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Teach Yourself Android Application Development in 24

1. Supported Image Description Required Format Extension Portable Network Graphics Preferred format png PNG lossless Nine Patch Stretchable Images Preferred format 9 png PNG lossless Working with Layouts 67 TABLE 4 4 Continued Supported Image Description Required Format Extension Joint Photographic Experts Group Acceptable format jpg JPEG JPG lossy Graphics Interchange Format Discouraged but gif GIF supported Using Image Resources Programmatically Images resources are encapsulated in the class BitmapDrawab1e To access a graphic resource file called res drawable logo png you would use the getDrawable method as follows BitmapDrawable logoBitmap BitmapDrawable getResources getDrawable R drawable logo Most of the time however you don t need to load a graphic directly Instead you can use the resource identifier as an attribute on a control such as an ImageView control The following code for example sets and loads the logo png graphic into an ImageView control named LogoImageView which must be defined within the layout ImageView logoView ImageView findViewById R id LogoImageView logoView setImageResource R drawable logo Working with Other Types of Drawables In addition to graphics files you can also create specially formatted XML files to describe other Drawable subclasses such as ShapeDrawable You can use the ShapeDrawable class to define different shape
2. OOOO 5 42 o o Tuesday April 6 Charging 50 A A a ik cel kd a ll jo fe fm fo fy fu fs fo fe als oe nied ne AEA a q 5 Now the Eclipse debugger is attached and your application runs as shown in Figure 1 7 a 5554 VanillaAVD ANDO ajo aw efdal fof fe fo fo Running and Debugging Applications 21 As you can see the application is very simple It displays a single TextView control with a line of text The application does nothing else Debugging Android Applications Using DDMS In addition to the normal Debug perspective built into Eclipse for stepping through code and debugging the ADT plug in adds the DDMS perspective While you have the application running take a quick look at this perspective in Eclipse You can get to the DDMS perspective see Figure 1 8 by clicking the Android DDMS icon is in the top right corner of Eclipse To switch back to the Eclipse Project Explorer sim ply choose the Java perspective from the top right corner of Eclipse If the DDMS perspective is not visible in Eclipse you can add it to your workspace By the __ by clicking the Open Perspective button in the top right next to the available per ay spectives or alternately choose Window Open Perspective To see a complete list of available perspectives select the Other option from the Open Perspective drop down menu Select the DDMS perspective and press OK FIGURE 1
3. Update question text TextSwitcher questionTextSwitcher TextSwitcher findViewById R id TextSwitcher_QuestionText questionTextSwitcher setText getQuestionText nextQuestionNumber Update question image ImageSwitcher questionImageSwitcher ImageSwitcher findViewById R id ImageSwitcher_QuestionImage Drawable image getQuestionImageDrawable nextQuestionNumber questionImageSwitcher setImageDrawable image else handleNoQuestions When you run the application and launch the game screen it should look some thing like Figure 12 4 Wiring Up Game Logic Have you evef _ climbed a mountain f X There are two easy ways to reset the quiz for testing purposes The first method is to delete the application s SharedPreferences file from the Android file system and restart the emulator You use the Eclipse DDMS perspective to navigate to the data directory of the application and delete the associated SharedPreferences file You can also uninstall and reinstall the application by using the Settings Menu item from the Android Home screen Adding a reset mechanism to the Been There Done That application is left as an exercise to the reader at the end of this hour Addressing Edge Cases If there are no more questions available you must inform the user This case is han dled by the handleNoQuestions method First you set the text and image to appropriate values as follo
4. Summary In this hour you built a simple App Widget for the Been There Done That applica tion to display the user s avatar nickname and score This hour covered all the implementation details of App Widget development including designing the layout and defining the App Widget properties You also added some simple event han dling allowing the user to click the App Widget to launch the Been There Done That application Finally you used a background service to handle processing of App Widget events and updates Q Is the Home screen the only place I can include App Widget controls A No Any App Widget host can hold App Widget controls The Home screen is simply the place you ll most commonly see App Widgets used See the docu mentation for AppWidgetHost and AppWidgetHostView for more details Q How do add more interactive features such as Button controls to an App Widget A If you want to add configuration controls to an App Widget and allow the user to trigger updates to the App Widget content you need to define each event separately and implement the appropriate click handlers to send specific event commands via PendingIntent objects to a registered receiver of the Intent objects Then the App Widget application needs to receive the com mands and process them accordingly updating the App Widget content as necessary You can find a complete example of an interactive App Widget pro vided in our article Handling
5. 440 gallery G gallery 227 228 game logic addressing edge cases 213 214 declaring string literals for question parsing 209 handling button presses 211 212 storing questions in hashtable 210 updating SharedPreferences to include game state settings 208 209 game screens adding resources to 200 202 defining features of 102 designing 197 200 updating layout of 202 203 ViewSwitcher controls 203 204 generating with ViewFactory 204 205 ImageSwitcher 206 207 TextSwitcher 205 gen com androidbook droid1 Rjava file 12 generating bitmaps 229 Geocoder class 247 geocoding services 246 247 gestures handling 351 352 GET method 282 285 getActivity method 376 getApplicationContext method 46 getAssets method 74 getAttributeValue method 157 getBestProvider method 244 getCacheDir method 359 getCallState method 279 getColor method 65 getConfiguration method 329 getDeviceld method 279 getDimension method 66 getDir method 359 getDrawable method 67 getFilesDir method 359 getFromLocation method 247 getFromLocationName method 247 getIntent method 54 getLastKnownLocation method 245 getLatitude method 245 getLongitude method 245 getNetworkInfo method 261 getNetworkType method 279 getOwnerActivity method 194 getPackagelnfo method 392 getPhoneType method 279 getPreferences method 50 110 getProvider me
6. Q changed the locale to Spanish Why are some applications still displaying in English A If an application has its default strings in English and has no Spanish resources available then the defaults will be used regardless of the language chosen 332 HOUR 19 Internationalizing Your Application Workshop Quiz 1 True or False An Android application can support multiple languages within a single APK file 2 True or False The number of languages supported by the Android platform and the Android Market is fixed 3 What language should your default resources be A English B Chinese C The language that appeals most to your target audience D Another language Answers 1 True An application can be compiled with resources in several different lan guages The Android platform can switch between these resources on the fly based upon the locale settings of the handset 2 False Android language support is being updated continuously New lan guages and locales are being added all the time 3 C Your default resources should be the ones that are most likely to load and be used Therefore it makes sense to design these resources to be in the lan guage and locale that appeals to the most number of users Exercises 1 Add a new set of string resource values to the Been There Done That applica tion in the language or locale of your choice Test the results in the Android emulator and on a real handset if
7. Try It Yourself Edit a String Resource If you inspect the main xml layout file of the project you will notice that it displays a simple layout with a single TextView control This user interface control simply displays a string In this case the string displayed is defined in the string resource called string hello To edit the string resource called string hello using the string resource editor follow these steps 1 Open the strings xml file in the resource editor 2 Select the String called hello and note the name hello and value Hello World DroidActivity shown in the resource editor 3 Within the Value field change the text to Hello Dave 4 Save the file If you switch to the strings xm tab and look through the raw XML you will notice that two string elements are defined within a lt resources gt block lt xml version 71 0 encoding utf 8 gt lt resources gt lt string name hello gt Hello Dave lt string gt lt string name app_name gt Droid 1 lt string gt lt resources gt The first is the string string hello The second is string app_name which con tains the name label for the application If you look at the Android manifest file again you will see string app_name used in the application configuration We will talk much more about project resources in Hour 4 Managing Application Resources For now let s move on to compiling and running the application Running an
8. 2 On the Emulator Control tab input the incoming phone number for exam ple 5551212 in the Telephony Actions section 3 Select the Voice radio button 4 Click the Call button 5 In the emulator you should see an incoming call Answer the call by clicking the Send button in the emulator 6 End the call at any time by clicking the End button in the emulator or by clicking the Hang Up button on the DDMS Emulator Control tab Debugging Applications with DDMS 33 Simulating Incoming SMS Messages to the Emulator You can simulate incoming SMS messages by using the DDMS Emulator DDMS see Figure 2 6 You send an SMS much as you initiate a voice call FIGURE 2 6 April 13 2010 fill 6 27PM Using the Fae Ech Retactor Run Navigate Search Project Window Heip Android Gea DDMS Emulator ne per ori e oe A Qe BH noeme EE O Control tab left Onine VanBaAVD 2 1 debug 3 to send an SMS n 2600 l t i message to the 38 601 1 2602 emulator right Lal a 8503 851 8634 8700 8542 Notifications 8646 Try It Yourself v Send an SMS to the Emulator To send an SMS message to an emulator running on your machine follow these steps 1 2 In DDMS choose the emulator you want a send an SMS to On the Emulator Control tab input the Incoming phone number for exam ple 5551212 in the Telephony Actions section Select the SMS radio button Type an SMS message Click the Sen
9. FIGURE 8 5 The Been There Done That game screen with an options menu Implementing the Main Menu Screen Handling Options Menu Selections To listen for when the user launches the options menu and selections a menu option you implement the onOptionsItemSelected method of the activity For example you start the appropriate activity by extracting the intent from the menu item selected as follows Override public boolean onOptionsItemSelected MenuItem item super onOptionsItemSelected item startActivity item getIntent return true The method given here for handling onOptionsItemSelected works as designed It s not technically required if the only thing your menu will do is launch the Intent set via the setIntent method However to add any other function ality to each MenuItem requires the implementation of this method There you have it You have created an options menu on the game screen If you save the class and run the application once more you will see that you can navi gate to the game screen press the Menu button and use a fully functional options menu see Figure 8 5 BM G 2 36 pm Th Game Screen Workshop 141 Summary You ve made excellent progress The main menu screen is now fully functional and you ve learned key skills for developing Android applications including how to use new layouts such as RelativeLayout as well as how to use the powerful ListView control
10. Force create _Greateavo Cancel Creating Debug and Run Configurations in Eclipse You are almost ready to launch your application You have one last task remaining You need to create a Debug configuration or a Run configuration for your project To do this take the following steps 1 In Eclipse choose Run Debug Configurations 2 Double click the Android Application item to create a new entry 3 Choose that new entry called New_configuration Running and Debugging Applications 4 Change the name of the entry to DroidDebug 5 Choose the Droid1 project by clicking the Browse button 6 On the Target tab check the box next to the AVD you created If you choose Manual on the Target tab instead of choosing Automatic and select ing an AVD you will be prompted to choose a target each time you launch this configuration This is useful when you re testing on a variety of handsets and emu lator configurations See Launching Android Applications on a Handset later in this hour for more information 7 Apply your changes by clicking the Apply button Your Debug Configurations dialog should look as shown in Figure 1 5 Create manage and run configurations Android Application Pexers a Android Application oe DroidDebug Ja Android JUnit Test Apache Tomcat Eclipse Application amp Eclipse Data Tools _ E Generic Server 5 Generic Server
11. HOUR 10 Building Forms to Collect User Input gt Email The unique identifier for each user This is a text field gt Password A mechanism to handle user verification This is a password text field When setting the password the user should input the password twice for verification The password text may be stored as plaintext gt Date of Birth To verify minimum age when necessary This is a date field but often displayed in a friendly way users understand and can easily interact with gt Gender A piece of demographic information which could be used for special score listings or to target ads to the user This can be set to three different set tings Male 1 Female 2 or Prefer Not to Say 0 Figure 10 1 shows a rough design for the settings screen NICKNAME 20 characters max EMAIL Will be used as unique account id PASSWORD Password requires entering twice to verify BIRTH DATE DOB requires entering Month Day Year GENDER Male Female or Prefer Not To Say Designing the Settings Screen 163 The application settings screen will contain quite a few different controls so you need to be careful with screen real estate You begin here as you have on other screens with the customary title bar Below the title you add a region for each setting Because you may add new settings in the future you should encapsulate the settings area of the screen within a ScrollView control This wa
12. The main xml layout file also references another resource the string resource called string hello which is defined in the strings xml resource file Layouts can also be created modified and used at runtime However in most cases using the XML layout files greatly improves code clarity and reuse There are two ways to format layout resources The simplest way is to use the layout resource editor in Eclipse to design and preview layout files You can also edit the XML layout files directly Designing Layouts Using the Layout Resource Editor You can design and preview layouts in Eclipse by using the layout resource editor see Figure 4 2 If you click on the project file res layout main xml you see a Layout tab which shows you the preview of the layout You can add and remove layout controls by using the Outline tab You can set individual properties and attributes by using the Properties tab Working with Layouts 2 Dron Lireo Arw fle Edt Bun Naigme Search Boject Retacior Window tiep ne 8 BIR O O Gr BEGCG Pnr 3 Package Engl N Hietanchy S emai SS singend eh T Editing config detadt E comandioicbookaroidlien 5 Droidt ou D en Generated hove Fue mi Googie APIs Android 2 1 assets bres 2 Crawable nop erawable iap trawable map AndroidMansestarn B cetar popernes Devices AD Config Landscape Locale Theme gt yours Darsonnetayout DoweFine Depancapierieview Dromers Be
13. lt LinearLayout xmlns android http schemas android com apk res android android id tid root android orientation vertical android layout_width wrap_content android layout_height wrap_content android background drawable bkgrnd gt lt TextView android id id TextView_Friend_Email android layout_width wrap_content android layout_height wrap_content android textSize dimen help_text_size android textStyle bold android text string settings_friend_email gt lt TextView gt lt EditText android id id EditText_Friend_Email android layout_height wrap_content android maxLength 50 android layout_width fill_ parent android maxLines 7 android inputType textEmailAddress gt lt EditText gt lt LinearLayout gt The contents of this layout are straightforward The layout is a LinearLayout con tainer with two controls a TextView label that prompts the user to enter an email address and an EditText control to receive the email address string from the user 296 HOUR 17 Adding Social Features Launching the Friend Request Dialog Clicking the Button control called Button_Friend_Email launches a dialog that allows the user to enter a friend s email address This dialog is launched much the same as any other dialog in the settings screen Button addFriend Button findViewById R id Button_Friend_Email addFriend setOnClickListener new View OnClickListener public void onClic
14. In the final version of the application you will be retrieving new batches of ques tions from the Internet For now though you can retrieve several batches of ques tions from local XML files The application can keep a working set of questions in memory and new batches of questions can be loaded as required To implement the game logic for the game screen follow these steps 1 Update SharedPreferences with game state settings 2 Handle the retrieval and parsing batches of trivia questions XML into a rele vant data structure 3 Implement Button click handling to drive the ImageSwitcher and TextSwitcher updates as well as the game logic 4 Handle edge cases such as when no more questions are available The following sections describe these steps in more detail Updating SharedPreferences to Include Game State Settings To keep track of game state you need to add two more Integer settings to the application SharedPreferences the game score and the current question number To add these preferences you first declare the preference name String values to the QuizActivity java class public static final String GAME_PREFERENCES_SCORE Score public static final String GAME_PREFERENCES_CURRENT_QUESTION CurQuestion Next you define the SharedPreferences object as a member variable of the QuizGameActivity class SharedPreferences mGameSettings You initialize the maameSettings member variable in the onCreate metho
15. There are many ways to develop an application server This implementation lever ages a very simple scalable server that uses Google App Engine http code google com appengine with Java and servlets The Google App Engine technology stores information using a schemaless object datastore with a query engine and support for atomic transactions While the implementation details of the application server are beyond the scope of this book it can be helpful to understand how it was designed Think of this example s application server as a black box with the following attributes gt The application server is always on and available for users gt The application server is remotely accessed via HTTP gt The application server stores data such as player settings scores and trivia questions Developing Network Applications 257 gt The application server can be queried for information such as top scores or batches of questions gt The application server uses JavaServer Pages JSP to handle HTTP requests and return the appropriate results in the XML format that the Android appli cation expects The application server developed for use with this book is not part of the code on By the the website for this book However it is available for your use in open source ay form at http code google com p triviaquizserver You could create an application server that has different characteristics than the one des
16. This screen displays instructions for how to play the game including controls goals scoring methods tips and tricks Starting to sound familiar This is the prototypical design of just about any mobile application game or otherwise on any platform Certainly you are free to implement any kind of user interface you desire There are no real user interface requirements on the Android platform other than that the application must be stable responsive and play nice with the rest of the Android system That said the best and most popular applications leverage the users existing experience with user interfaces It s best to improve upon those features when necessary rather than reinvent them so you don t force the user to exert time and effort to learn your application in order to use it properly Determining Application Activity Requirements You need to implement five activity classes one for each feature of the game gt SplashActivity This activity serves as the default activity to launch It sim ply displays a layout maybe just a big graphic plays music for several sec onds and then launches MenuActivity gt MenuActivity This activity is pretty straightforward Its layout has several buttons each corresponding to a feature of the application The onClick handlers for each button trigger cause the associated activity to launch gt PlayActivity The real application guts are implemented here T
17. waai HOUR 16 Adding More Network Support You could also use a List container of BasicNameValuePair objects in conjunc tion with the URLEncodedUtils format method However for primitive values such as integers no additional encoding is needed Uploading Player Avatars with HTTP POST To upload binary data such as an avatar image you need to consider using an HTTP POST request as opposed to a GET request This allows you to submit the avatar content much as you would in an HTML web form The application server can then handle the POST request appropriately and save a copy of the player avatar see Figure 16 2 Whenever you are storing non primitive types of data consider the best practices for the datastore your application server relies upon For example one common practice for SQL databases is to store the address to the image in the database but not store the binary data as a blob Adding JAR Files to Your Android Project Ideally you want to use the HttpClient class to upload a multipart MIME message containing the avatar and some other important information for the application server However as of this writing Apache HttpClient support within the Android Uploading Data to a Remote Application Server 287 SDK is incomplete The Android SDK does not yet contain multipart MIME support but this is likely to change in a future version of the SDK For now if you want to include multipart M
18. 313 314 ImageButton events 222 223 ListView events custom dividers 136 custom selectors 137 listening for 135 136 execute method 267 298 Export Android Application command 389 Extract Local Variable tool 419 Extract Method tool 419 F Facebook Platform for Mobile 301 Facebook support 300 301 fade_in xml animation 120 fade_in2 xml animation 120 favorite place feature accessing LBS location based services 244 245 designing 233 234 dialog 235 237 enabling location testing on emulator 241 243 geocoding services 246 247 guidelines for LBS location based services 240 241 implementing framework for 237 240 layout updates 234 235 maps launching map applications with intents 248 249 working with Google APIs 250 251 receiving location updates 245 feasibility testing 373 FierceDeveloper 425 File Explorer DDMS 31 file system browsing with DDMS 31 fileList method 359 files AndroidManifest xml See AndroidManifest xml file default properties 12 DroidActivity java 12 explained 358 help xml 144 JAR files 286 287 main xml 13 quizhelp txt 145 R java class file 12 62 raw resource files 72 73 147 148 scores xml 150 154 strings xml 13 widget xml 308 XML files accessing 72 editing 24 formatting 71 parsing 156 157 retrieving 156 XML parsers 74 How can we make this filling ListView control 134 135 filters log filter
19. 414 Eclipse IDE installation 410 Wireless Developer Network 426 wizards Test Application Project Wizard 375 X Y Z XML files accessing 72 designing layouts with 69 editing 24 formatting 71 parsing 156 157 retrieving 156 XML parsers 74 XML utility packages 71 72 XmIPullParser class 74 262 269 XmlResourceParser class 156 157 zipalign utility 390
20. A Sometimes you can t The official documentation for the Android system resources does not describe each resource If you are confused about what a specific system resource is or how it works you can either experiment with it or examine its resource definition Android system resources are defined in the tools lib res default directory of the Android SDK Q Must string color and dimension resources be stored in separate XML files A Technically no However it is highly recommended For example localization and internationalization may require different strings but the dimensions might remain the same ones Keeping the resource types separate keeps them organized Q Which XML parser should use A Our tests have shown that the SAX parser is the most efficient XML parser closely followed by XMLPullParser and we recommend this parser for most purposes However the choice is yours and you should test your specific XML implementation to determine the appropriate parser for your application s needs Q What is the difference between project resources and project assets A Project resources are compiled into the application and easily accessed using the getResources method Application assets are used less frequently to store uncompiled files within the application package file that is installed on the handset Assets are accessed using the getAssets method Workshop 75 Workshop Quiz 1 What color formats
21. A notification in the status bar Ott HOUR 21 Diving Deeper into Android Alerting the User with Notifications An application can alert the user even when the application isn t actively running in the foreground using a notification For example a messaging application might notify users when a new message is delivered as shown in Figure 21 1 BR G 4 53 pm Android Clear notifications Si Hi there This is even more text 4 55 PM Notifications come in a variety of forms An application can use several different kinds of notifications provided that it has the appropriate permissions registered in the Android manifest file gt Display a text notification on the status bar gt Play a sound gt Vibrate the device gt Change the indicator light color and blinking frequency Not all devices support every notification type For example some devices might not have the ability to vibrate or play sounds or have an indicator light Designing Advanced User Interfaces 349 Notifications are created and triggered using the NotificationManager system serv ice android app NotificationManager Once it is requested you can create a Notification object by setting the appropriate notification text vibration light and sound settings and use the notify class method to trigger the notification Take special care to use notifications appropriately so as not to be a nuisance to Wa
22. Adding an Avatar to the Settings Screen Layout To update the settings screen you begin by adding new resources to the project and then you update the settings xml layout resource to reflect the new settings screen design To enable the avatar feature in the Been There Done That application you need to add some new resources including any String Dimension Color and Drawable resources you might need For example you should add a new graphic resource to show as the default avatar Updating the Settings Screen Layout The settings xml layout file dictates the user interface of the settings screen You need to reopen this layout file in the Eclipse layout resource editor and make the fol lowing changes 1 First find the TextView control called TextView_Nickname in the file Above this control and inside the ScrollView control add a new LinearLayout con trol and set its orientation attribute to horizontal Set the layout_width and layout_height attributes to fill_parent 220 FIGURE 13 3 The settings screen with the avatar feature LI ri oO 13 Working with Images and the Camera 2 Within the LinearLayout control add an ImageButton control called ImageButton_ Avatar Set the layout_width and layout_height attributes to wrap_content You need to be able to scale the avatar graphic while preserv ing its aspect ratio so set its adjustViewBounds attribute to true and its scaleType attribute to fitXY You will al
23. Android SDK Designing the Favorite Place Feature Mobile users are always on the go and mobile applications that include integration with LBS have become incredibly popular The Android platform makes it simple to add LBS support to applications The degree to which LBS support is incorporated into an applica tion is a design choice for the developer and there are a number of options Because the Been There Done That application is primarily a game you want to include some of the most common LBS features You do this by adding a favorite place feature to the settings screen As you build this feature you will learn about some of the other options available for building more powerful LBS applications 234 FIGURE 14 1 Rough design of the favorite place feature HOUR 14 Adding Support for Location Based Services On the settings screen the user will be able to choose to label and save the handset s last known location as his or her favorite place or type in a place name such as an address a city or a landmark for example New York City Iceland Yellowstone National Park 90210 The application then uses any geocoding service providers available to resolve these locations into the appropriate GPS coordinates To incorporate this kind of feature into the Been There Done That Settings screen you need to modify the screen design slightly to include the new favorite place fea ture Figure 14 1 shows a rough design of how th
24. Creating Custom Log Filters Every Android log statement includes a tag These tags can be used with filters defined in LogCat To add a new filter click the green plus sign button in the LogCat pane Name the filter perhaps using the tag name and fill in the tag you want to use Now there is another tab in LogCat that will show messages that contain this tag In addition you can create filters that display items by severity level Android convention has largely settled on creating tags based on the name of the class You see this frequently in the code provided with this book Note that we cre ate a constant in each class with the same variable name to simplify each logging call Here s an example public static final String DEBUG_TAG MyClassName This convention isn t a requirement though Tags could be organized around specif ic tasks that span many activities or could use any other logical organization that works for your needs Integrating Source Control Moving Tabs Around Eclipse provides some pretty decent layouts with the default perspectives However not everyone works the same way and with Android a few perspectives have poor default layouts for us For instance the Properties tab is usually found on the bottom For code this works fine because this tab is only a few lines high But for layouts in Android this doesn t work so well Luckily in Eclipse this is easy to fix Simply drag the tab by left
25. Finally the scale operation scales from 10 to 100 over the same 2 second period This entire ani mation takes 2 seconds to complete After you have saved all three of your animation files you can begin to apply the animations to specific views Animating Specific Views Animations must be applied and managed programmatically Remember costly operations such as animations should be stopped if the application is paused for some reason The animation can resume when the application comes back into the foreground Let s start with a simplest case applying the fade_in animation to your title TextView control called TextViewTopTitle All you need to do is retrieve an instance of your TextView control in the onCreate method of the QuizSplashActivity class load the animation resource into an Animation object and call the startAnimation method of the TextView control TextView logoi TextView findViewById R id 7TextViewTopTitle Animation fade1 AnimationUtils loadAnimation this R anim fade_in logo1 startAnimation fade1 121 122 HOUR 7 Implementing an Animated Splash Screen When an animation must be stopped for instance in the onPause method of the activity you simply call the clearAnimation method For instance the following onPause method demonstrates this for the corner logos Override protected void onPause super onPause Stop the animation TextView logoi TextView findViewByI
26. HOUR 13 Working with Images and the Camera graphics on the handset Resource URIs can be referenced by resource identifier or by resource type name The Uri address format for the resource identifier method is as follows android resource package res id For example you could use the following Uri to access a Drawable resource called avatar png by its resource identifier Uri path Uri parse android resource com androidbook triviaquiz13 R drawable avatar The Uri address format for the resource type name method is as follows android resource package res type res name For example you could use the following Uri to access a Drawable resource called avatar png by its resource type name Uri path Uri parse android resource com androidbook triviaquiz13 drawable avatar When you have a valid Uri for the Drawable resource you can use it with the setImageURI method of an ImageButton control as follows ImageButton avatarButton ImageButton findViewById R id ImageButton_ Avatar avatarButton setImageURI path Handling ImageButton Events You handle ImageButton events such as clicks exactly the same way as you would with any View control by using click listeners For the avatar ImageButton control you want to handle clicks and long clicks Handling Clicks with setOnClickListener To listen and handle when a user clicks on the avatar ImageButton control you must implement the View
27. MenuActivity class This intent requests the launch of the target activity named MenuActivity by its class This class must be implemented elsewhere within the package Because the MenuActivity class is defined within this application s package it must be registered as an activity within the Android manifest file In fact you could use this method to launch every activity in your theoretical game application however this is just one way to launch an activity Launching an Activity for a Result Sometimes an activity wants to launch a related activity and get the result instead of launching an entirely independent activity In this case you can use the Working with Activities 49 Activity startActivityForResult method The result will be returned in the Intent parameter of the calling activity s onActivityResult method We will talk more about how to pass data using an Intent parameter in a moment Managing Activity State Applications can be interrupted when various higher priority events such as phone calls take precedence There can be only one active application at a time specifical ly a single application activity can be in the foreground at any given time Android applications are responsible for managing their state as well as their mem ory resources and data The Android operating system may terminate an activity that has been paused stopped or destroyed when memory is low This means that any activ
28. TABLE 7 1 Common Layout Controls Key Layout Control Name Description Attributes Elements LinearLayout Each child view is placed Orientation vertical or after the previous one in horizontal a single row or column RelativeLayout Each child view is placed in Many alignment attributes relation to the other views to control where a child in the layout or relative to view is positioned relative the edges of the parent to other child View controls layout FrameLayout Each child view is stacked The order of placement of within the frame relative to child View controls is the top left corner View important when used with controls may overlap appropriate gravity settings TableLayout Each child view is a cell in Each row requires a a grid of rows and columns TableRow element As of Android 1 5 SDK the AbsoluteLayout control which requires specific X Y values was deprecated yet has remained available for use Although this control is not recommended for use occasionally having exact X Y sizing control can be useful for specific kinds of layouts that require pixel perfect precision The SDK s own WebView control uses this layout Layouts and their child View controls have certain attributes that help control their behavior For example all layouts share the attributes android layout_width and android layout_height which control how wide and high an item is These attrib ute values can be dimensions such as
29. You ve also learned about the other types of navigation mechanisms avail able in Android and implemented an options menu on the game screen Q amp A Q What is the difference between a ListView control s setOnClickListener method and the setOnItemClickListener method A The setOnClickListener method listens for a click anywhere in the entire ListView control The setOnItemClickListener method listens for a click in a specific View item within the ListView control Q There is no default item selected in the ListView control I created How can l have it default to a specific item A To have a ListView control highlight a specific list item by default use the setSelection method Workshop Quiz 1 True or False Context menus are launched using the Menu button 2 What mechanism acts as the glue between a data source and a ListView control A A database B An interpolator C A data adapter 142 HOUR 8 Implementing the Main Menu Screen 3 What type of layout is most appropriate for aligning child View controls in relation to the parent control A RelativeLayout B AbsoluteLayout C LinearLayout True or False Using ListActivity is a convenient way to build screens that are just ListView objects Answers 1 False Options menus are launched using the Menu button Context menus 4 are launched using a long click on a View control C A data adapter such as ArrayAdapter is used t
30. adding tabs to 155 adding to scores screen 150 configuring 155 setting default tab 155 updating layout of 152 154 scores xml file 152 154 ScoresActivity class 44 Screen Capture button DDMS 33 34 screen headers building with RelativeLayout control 129 screen orientations creating custom layout for landscape mode 335 337 handling 339 listening for screen orienta tion changes 338 344 screenshots taking of emulator or handset 33 34 SD card images 38 SDK Android 28 defining 343 detecting programmatically 343 453 setOnltemClickListener method installing explained 411 Linux installations 412 Mac OS X installations 412 Windows installations 411 specifying target SDK 342 upgrading 413 versions 341 342 searching global search 361 secure applications 367 Secure Hash Algorithm SHA 285 security application permissions 347 copy protection 406 self distribution 402 403 sensor data reading 362 SensorManager object 362 servers application servers 256 257 availability checking 261 uploading data to determining data to send 277 278 explained 281 with HTTP GET method 282 285 with HTTP POST method 286 288 Service objects creating 316 317 starting stopping 317 318 services creating 316 317 NotificationManager system service 349 starting stopping 317 318 ServiceTestCase class 380 setAdapter method 173 setConte
31. amp Noble nook digital photo frames and a variety of other consumer electronics There are even proof of concept appliances such as an Android microwave and washer dryer combo Hey why not See http bit ly bGqmZp Mobile operators and carriers are taking the platform seriously and spending gazillions on ad campaigns for Android phones like Verizon s Droid campaign In the past year or so the Android platform has transitioned from a gearheads only plat form to providing some serious competition to more established platforms Yes we re talk ing about platforms such as the iPhone But let s not digress into an argument over whose platform is better so early okay Because honestly you re wasting your time if you think there s one platform to rule them all The reality is people the world over use different phones in different places CDMA GSM and for different reasons price availability coverage quality feature set design familiarity compatibility There is no one size fits all answer to this debate Having developed for just about every major mobile platform out there we are keenly aware of the benefits and drawbacks of each platform We do not presume to claim that one platform is better than another in general each platform has distinct advantages over the rest and these advantages can be maximized The trick is to know which platform to use for a given project Sometimes the answer is to use as man
32. and drawable hdpi For this book the icon quizicon png file contains the hour number to differentiate each project visually Implementing Application Activities To implement a base Activity class you simply copy the source file called QuizSplashActivity java Then you create a new class file called QuizActivity This class should look very simple for now Implementing an Application Prototype 105 package com androidbook triviaquiz6 import android app Activity public class QuizActivity extends Activity public static final String GAME_PREFERENCES GamePrefs You will add to this class later Next you update the QuizSplashActivity class to extend from the QuizActivity class instead of directly from the Activity class Creating the Rest of the Application Activities You can copy the QuizSplashActivity five more times once for each activity you need QuizMenuActivity QUizHelpActivity QuizScoresActivity QuizSettingsActivity and QuizGameActivity Note the handy way that Eclipse updates the class name when you copy a class file You can also create class files by right clicking the package name com android book triviaquiz and choosing New Class Eclipse presents a dialog where you can fill in class file settings For more tips on working with Eclipse check out Appendix B Eclipse IDE Tips By the and Tricks ay Note that there is an error in each Java file This is because each activity
33. debugging 414 developing for Android SDKs 341 342 choosing application s target platform 342 defining Android SDK 343 designing for backward compatibility 342 detecting SDK programmatically 343 specifying target SDK 342 developing for different devices configuration management 333 335 handset features 341 screen orientations 335 339 344 Dialer application 37 Dialog class 182 dialogs 53 54 181 AlertDialog 182 CharacterPickerDialog 182 custom password dialog adding to QuizSettingsActivity class 190 193 designing 188 189 implementing layout 190 launching 193 DatePickerDialog 182 adding to QuizSettingsActivity class 184 185 initializing 185 186 launching 186 187 DatePickerDialog class 184 defining 183 Dialog 182 dismissing 184 favorite place dialog 235 237 initializing 183 437 Eclipse IDE launching 183 documentation 27 29 res files 15 16 life cycle of 182 183 code comments 416 string resources 16 methods 53 online versus local SDK launching on handset 22 23 ProgressDialog 182 documentation 40 launching with emulator removing from use 184 dolnBackground method 265 19 24 TimePickerDialog 182 268 ete 283 285 29 project files 12 13 digital signatures 387 390 downloading dimensions 65 66 Android SDK 9 411 directories Eclipse IDE 410 E assets 12 question batches 271 273 explained 358 cae ore e method Log class 54 layout 15 i i wa 361 n
34. definition of 59 referencing 62 storing 60 62 avatars adding to settings screen layout 219 220 bitmaps 228 230 designing 217 219 gallery 227 228 ImageButton controls 221 223 launching activities and handling results 224 225 photo taking with camera 225 227 Been There Done That game See Been There Done That application configuring application settings linking secondary libraries 82 naming Android packages 82 naming applications 84 providing application description 85 providing application icons 84 setting debug information 85 setting minimum Android SDK version 83 version code 82 version name 82 versioning applications 82 83 context menus 138 copy protection 406 designing application activity requirements 44 45 application features 43 44 application functionality 45 46 for response during low memory conditions 55 dialogs See dialogs game logic addressing edge cases 213 214 declaring string literals for question parsing 209 handling button presses 211 212 storing questions in hashtable 210 updating SharedPreferences to include game state settings 208 209 game screens adding resources to 200 202 designing 197 200 updating layout of 202 203 help screens adding resources to 145 146 designing 144 raw resource files 147 148 updating layout of 146 installing 390 391 intents explained 51 launching other applications wi
35. ductory Java book or do an online tutorial and have enough Java knowledge to make it through this book alive We do assume that you re somewhat comfortable installing applications on a computer for example Eclipse the Java JDK and the Android SDK and tools and drivers for USB access to a phone and we assume that you can navigate your way around an Android handset well enough to launch applications and such No wireless development experience is neces sary How This Book Is Structured In 24 easy one hour lessons you ll design and develop a fully functional network and LBS Location Based Services enabled Android application complete with social features Each lesson builds on your knowledge of newly introduced Android concepts and you ll iterative ly improve your application from chapter to chapter This book is divided into six parts gt Part I Android Fundamentals In Part I you ll get an introduction to Android become familiar with the Android SDK and tools install the development tools and write your first Android application Part I also introduces the design principles necessary to write Android applications including how Android applications are structured and configured as well as how to incorporate application resources such as strings graphics and user interface compo nents into your projects gt Part II Building an Application Framework In Part II you ll begin developing an application framew
36. gt Draw 9 Patch tool Helps developers design stretchable PNG files gt AIDL Compiler Helps developers create remote interfaces to facilitate inter process communication IPC on the Android platform gt mksdcard command line utility Allows developers to create stand alone SD card images for use within AVDs and the emulator Developing Android Applications Without Eclipse Eclipse is the preferred development environment for Android but it is not required for development The ADT plug in for Eclipse provides a convenient entry point for many of the underlying development tools for creating debugging pack aging and signing Android applications Developers who do not use Eclipse or require some of the more powerful debug ging features not available in the Eclipse ADT plug in can access these underlying tools directly from the command line Tools such as the following are found in the tools directory of the Android SDK gt android Creates Android project files and to manage AVDs gt aapt Android Asset Packaging Tool Packages Android project files into apk files for installation on the emulator and handset gt ddms Dalvik Debug Monitor Service Has a user interface of its own which resembles the Eclipse DDMS perspective gt adb Android Debug Bridge Has a command line interface for interacting with the emulator and the device Summary The Android SDK ships with a number of powerful tools t
37. id ImageSwitcher_QuestionImage 11 Below the TextSwitcher control add a Button control with an id of id Button_Yes Set layout_width to wrap_content and layout_height to wrap_content Also set its layout_alignParentBottom and layout_alignParentLeft attributes to true Set its text attribute toa resource string Yes and tweak any other attributes to make the Button control look nice 12 Add another Button control below the previous Button control with an id of id Button_No Set the Layout_width to wrap_content and the layout_height to wrap_content Also set its layout_alignParentBottom and layout_alignParentRight attributes to true Set its text attribute toa resource string No and tweak any other attributes to make the Button con trol look nice At this point save the game xml layout file The Eclipse layout resource editor does not display TextSwitcher or Watch _ ImageSwitcher controls in design mode You must view the resulting TextView ut and ImageView controls generated by the switchers by using the Android emula tor In this case the layout designer does not reflect actual application look and feel Working with ViewSwitcher Controls For situations in which an activity is going to be updating the content of a View control repeatedly the Android SDK provides a mechanism called a ViewSwitcher control Using a ViewSwitcher is an efficient way to update content on a screen A ViewSwitcher control has two
38. if strPassword1 equals strPassword2 Editor editor mGameSettings edit editor putString GAME_PREFERENCES_PASSWORD strPassword1 editor commit passwordInfo setText R string settings_pwd_set else Log d DEBUG_TAG Passwords do not match Not saving Keeping old password if set QuizSettingsActivity this removeDialog PASSWORD_DIALOG_ID 5 The negative button Cancel simply returns the user to the main screen You config ure the negative button using the setNegativeButton method of the builder builder setNegativeButton android R string cancel new DialogInterface OnClickListener public void onClick DialogInterface dialog int whichButton QuizSettingsActivity this removeDialog PASSWORD_DIALOG_ID Working with Custom Dialogs When your dialog is fully configured using the builder you call the create method to generate the custom AlertDialog and return it AlertDialog passwordDialog builder create return passwordDialog Launching the Custom Password Dialog A custom dialog such as your password dialog is launched the same way as a regu lar dialog using the showDialog method of the activity On the settings screen of the Been There Done That application the user triggers the custom password dia log to launch by pressing the Button control called Button_Password Therefore you can register for click events on this Button control and launch the password dialog acc
39. ifest xmlns android http schemas android com apk res android package com androidbook droid1 android versionCode 7 android versionName 7 0 gt lt application android icon drawable icon android label string app_name gt lt activity android name DroidActivity android label string app_name gt lt intent filter gt lt action android name android intent action MAIN gt lt category android name android intent category LAUNCHER gt lt intent filter gt lt activity gt lt application gt lt uses sdk android minSdkVersion 7 gt nifest gt Familiarizing Yourself with Eclipse 15 Because all Android resource files including the Android manifest file are simply Did you__ XML files you are always able to edit the raw resource files instead of using the resource editors You can create a new Android XML file by clicking the Android XML creator icon which looks like a file with the letter a and a plus sign ap on the Eclipse toolbar Try It Yourself v Edit the Android Manifest File Now let s edit the Android manifest file One setting you re going to want to know about is the debuggable attribute You will not be able to debug your application until you set this value so follow these steps 1 2 3 4 Open the AndroidManifest xm1 file in the resource editor Navigate to the Application tab Pull down the drop down for the debuggable attribute and choo
40. opportunities for the application gt How can my end user invite contacts to play my application Will users enter their friends email addresses phone numbers or user names to connect with them Will invitations be delivered via email SMS Will player relationships like friendships need to be confirmed by both sides gt What existing social networking sites Facebook Twitter and so on are my target users a part of and does it make sense for my application to integrate any of these sites features gt How will my application protect its users and their friends privacy What guidelines will I use to determine what the application and my company can and cannot do with private user data Supporting Basic Player Relationships Social applications rely on relationships between users Different applications describe these relationships using different terminology The terms contact and friend are the most widely used terms to describe user relationships but some sites use unique terminology such as user s circle or follower Clever applications sometimes refer to friends or contacts within the theme of the game For example a clever war themed game might use the phrase recruit fellow warriors for the mission instead of the more generic invite your friends to play the game by giving us their email addresses Adding Friend Support to Your Application For the Been There Done That application you wil
41. tab 81 Application tab 78 79 Instrumentation tab 80 Manifest tab 78 79 Permissions tab 79 80 methods creating 415 refactoring 418 420 Rename tool 417 418 tabs rearranging 421 edge case testing 370 editing AndroidManifest xml file AndroidManifest xml tab 81 Application tab 78 79 Instrumentation tab 80 Manifest tab 78 79 Permissions tab 79 80 code 416 417 project resources AndroidManifest xml file 13 15 res files 15 16 string resources 16 XML files 24 EditText controls committing EditText input 169 configuring 168 handling text input 168 listening for EditText key strokes 169 170 elements See tags emulator configuring location of 241 enabling location testing on 241 243 explained 35 incoming calls simulating with DDMS 31 32 incoming SMS messages simulating with DDMS 33 launching Android applications with 19 21 launching applications in 109 limitations 35 providing input to 36 SD card images with 38 skins 38 40 taking screenshots of 33 34 testing network applications on 258 testing on 372 Emulator Control DDMS 31 33 enabling friend requests AsyncTask class 297 298 Friend Request dialog 296 settings screen layout 293 295 location testing on emulator 241 243 USB debugging 413 414 enhancing player relationships 299 300 errors build errors 420 events handling animation life cycle events 123 handling in App Widgets
42. the settings screen of the Been There Done That application works fine in both land scape and portrait modes because each setting is stacked in a LinearLayout control within a scrolling area that can scale well to any size However some layouts such as the splash or game screen may need some special tweaking for each orientation There are many strategies for supporting different screen sizes and orientations Here are some tips for developing layouts that work for multiple types of screens gt Don t crowd screens Keep them simple gt Use scalable container views such as ScrollView and ListView gt Scale and grow screens in only one direction vertically or horizontally not both gt Don t hard code the positions of screen elements Instead use relative posi tions and layouts such as RelativeLayout gt Avoid AbsoluteLayout and other pixel specific layout settings gt Use stretchable graphics such as Nine Patch gt Keep resources as small as possible so they load fast when the screen orienta tions change The Android developer website contains a helpful set of guidelines for supporting Did you__ multiple screens http developer android com guide practices screens_ ow support html Supporting Different Screen Characteristics Android devices come with a wide variety of display settings including different screen sizes densities aspect ratios and resolutions Also different devices have
43. xii Teach Yourself Android Application Development in 24 Hours HOUR 24 Publishing on the Android Market 395 Selling on the Android Market 395 Exploring Other Android Publishing Options 402 Summary 405 Q amp A 405 Workshop 406 Part VI Appendixes APPENDIX A Configuring Your Android Development Environment 409 Development Machine Prerequisites 409 Installing the Java Development Kit 410 Installing the Eclipse IDE 410 Installing the Android SDK 411 Installing and Configuring the Android Plug in for Eclipse ADT 412 Upgrading the Android SDK 413 Configuring Development Hardware for Device Debugging 413 APPENDIX B Eclipse IDE Tips and Tricks 415 Creating New Classes and Methods 415 Organizing Imports 415 Documenting Code 416 Using Auto Complete 416 Editing Code Efficiently 416 Renaming Almost Anything 417 Formatting Code 418 Organizing Code 418 Fun with Refactoring 418 Resolving Mysterious Build Errors 420 Creating Custom Log Filters 420 Moving Tabs Around 421 Integrating Source Control 421 xiii Contents APPENDIX C Supplementary Materials 423 Accessing the Publisher s Website ae ea Bee l vo 423 Accessing the Authors Website 424 Contacting the Authors 425 reyeraging Online Android Resources ae iiei een 429 427 xiv About the Authors Lauren Darcey is responsible for the technical leadership and direction of a small soft ware company specializing in mobile technologies including Android iPhone Blac
44. you will build a custom dialog from the AlertDialog class The favorite place setting will be stored internally in three parts gt The name of the location a String value gt The latitude of the location a float value gt The longitude of the location a float value 235 FIGURE 14 2 The settings screen layout updates required for the favorite place feature 236 FIGURE 14 3 Rough design of the favorite place dialog HOUR 14 Adding Support for Location Based Services Technically you could also retrieve and store the altitude of the location but with most map applications these days people want a bird s eye view on a two dimensional space To keep the dialog simple you can offer the user two choices use the last known location provided that the handset GPS provider exists and has this information or enter a string into an EditText control which the geocoding functionality available in the Android SDK translates into GPS coordinates When you have latitude and longitude information on the location you can include the ability to launch into the Maps application if it is available on the device Figure 14 3 shows a rough design of the favorite place dialog FAVORITE PLACE Place name resolved when user leaves focus of control COORDINATES Show resolved GPS coordinates for location Implementing the Favorite Place Dialog Layout You need to create a new layout file where you can st
45. 108 debug information setting for applications 85 device debugging 414 USB debugging 413 414 default resources specifying 325 default tabs setting 155 default properties file 12 defect tracking systems 369 defects 369 defining Android SDK 343 deleteFile method 359 descriptions adding to applications 85 designating launch activity 87 88 designing applications activity requirements 44 45 96 97 App Widget layouts 308 application features 43 44 application functionality 45 46 avatars 217 219 backward compatibility 342 favorite place feature 233 234 game screens 102 197 200 help screens 98 99 144 high level game features 96 layouts with Layout Resource Editor 68 70 with XML 69 main menu screens 98 network applications application servers 256 257 explained 255 256 progress bars 257 password dialog 188 189 response during low memory conditions 55 scores screens 100 149 settings screens 100 101 161 163 splash screens 97 98 113 114 input forms 55 detecting SDK programmatically 343 determinate progress displaying with progress bars 263 determining locales 329 330 Dev Guide tab Android documentation 28 Dev Tools 38 110 developer accounts Android Market benefits 402 signing up for 396 397 Developer Challenges 9 Developer com 426 developing network applications 257 258 device fragmentation 371 372 devices
46. 11 value 44 427896 110 585632 The 11 value 44 427896 110 585632 stands for latitude 44 427896 and longitude 110 585632 You can double check these coordinates by pasting them into Google Maps again and seeing if the map pinpoints the same place location again 242 HOUR 14 Adding Support for Location Based Services To seed the emulator with a latitude and longitude follow these steps 1 Launch the emulator If you re running an application click the Home button 2 Launch the Maps application 3 Click the Menu button 4 Choose the My Location menu item see Figure 14 7 FIGURE 14 7 The Maps applica tion in the Android emulator Search Directions Layers 2 My Location Join Latitude Open Eclipse and click on the DDMS perspective Choose the emulator instance you want to send a location fix to In the Emulator Control pane scroll down to the location control eo nN 2 wo Enter the longitude and latitude of your desired location Try the coordinates for Yellowstone National Park latitude 44 427896 and longitude 110 585632 see Figure 14 8 9 Click Send Using Location Based Services Back in the emulator you ll notice that the Google map is now showing the location you seeded Your screen should now display your location as Yellowstone National Park as shown in Figure 14 9 You can also use the emulator console command line tool to send a location fix with
47. 150 TabHost control 150 155 updating layout of 152 154 security 367 setting debug information for 85 settings screens adding resources to 165 166 Button controls 170 172 designing 161 163 431 ApplicationTestCase class EditText controls 168 170 SharedPreferences 175 178 Spinner controls 172 174 updating layout of 166 167 splash screens adding resources to 116 117 animation 119 124 designing 113 114 Layout controls 114 116 updating layout of 117 119 stability 367 testing 40 automated testing 373 380 best practices 367 370 on emulator 372 managing test environment 371 372 on target handsets 373 types of testing 370 uploading to Android Market 397 400 verifying 391 392 version code setting 82 version name setting 82 ViewSwitcher controls 203 204 generating with ViewFactory 204 205 ImageSwitcher 206 207 TextSwitcher 205 ApplicationTestCase class 379 more useful Email us at indexes samspublishing com 432 AppWidgetProvider class AppWidgetProvider class 309 311 ARCHOS 5 Internet tablet 402 assertTrue method 377 assets compared to project resources 74 definition of 73 assets folder 12 asynchronous tasks running with AsyncTask class 265 266 with threads and handlers 266 AsyncTask class 265 266 282 285 288 297 298 audio 353 authors contact information 425 authors website 424 425 Auto comp
48. 177 178 saving settings to 176 Spinner controls 172 configuring 173 handling Spinner selections 173 174 listening for selection events 174 updating layout of 166 167 updating to enable friend requests 293 295 setTitle method 192 setup method 155 376 SHA Secure Hash Algorithm 285 ShapeDrawable class 67 SharedPreferences 46 47 defining SharedPreferences entries 175 reading settings from 177 178 retrieving 107 108 saving 107 saving settings to 176 updating to include game state settings 208 209 sharing data content providers Browser 360 CallLog 360 Contacts 360 explained 360 361 live folders 364 MediaStore 360 UserDictionary 360 directories 358 files 358 form data with SharedPreferences defining SharedPreferences entries 175 reading settings from 177 178 saving settings to 176 overview 358 SQLite databases 359 SHOP4APPS 404 showDialog method 53 183 186 193 194 signing applications 387 390 SIM information retrieving 280 simulating incoming calls to emulator 31 32 incoming SMS messages to emulator 33 skins emulator 38 40 SlideME 404 sliding drawer 37 SMS messages simulating incoming SMS messages to emulator 33 SmsManager class 281 SmsMessage class 281 social features friend support displaying friends scores 298 enabling friend requests 293 298 enhancing player relationships 299 300 explained 2
49. 311 background operations 314 318 controls 318 event handling 313 314 explained 305 306 layout 308 methods 309 multiple instances of 319 properties 306 307 RemoteViews object 311 application preferences creating 106 107 retrieving shared preferences 107 108 saving shared preferences 107 avatars adding to settings screen layout 219 220 bitmaps 228 230 designing 217 219 gallery 227 228 ImageButton controls 221 223 launching activities and handling results 224 225 photo taking with camera 225 227 context menus 138 creating new project 103 debug configuration 108 explained 95 favorite place feature accessing LBS location based services 244 245 designing 233 234 dialog 235 237 enabling location testing on emulator 241 243 geocoding services 246 247 guidelines for LBS location based services 240 241 implementing framework for 237 240 layout updates 234 235 maps 248 251 receiving location updates 245 How can we make this 433 Been There Done That application friend support displaying friends scores 298 enabling friend requests 293 298 enhancing player relationships 299 300 explained 292 293 game logic addressing edge cases 213 214 declaring string literals for question parsing 209 handling button presses 211 212 storing questions in hashtable 210 updating SharedPreferences to include game state
50. Designing the Main Menu Screen _ 127 Implementing the Main Menu Screen Layout 131 Working with the ListView Control M EAA 134 Working with Other Menu Types 138 Summary 141 Q amp A CEE AE T E ee A E E aoc 141 HOUR S Developing the Help and Scores Screens D 143 Designing the Help Screen 144 Implementing the Help Screen Layout cc wes L45 Working with Files f 147 Designing the Scores Screen 149 Implementing the Scores Screen Layout ccc LSL Designing a Screen with Tabs ers siete cence PE a 154 Working with XML 156 Summary siese E dina ceoumnaseeniih noiire E LOO QRA ainni E fie E T teenies LOS Workshop 159 viii Teach Yourself Android Application Development in 24 Hours HOUR 10 Building Forms to Collect User Input 161 Designing the Settings Screen areas sisi ae 161 Implementing the Settings Screen Layout 165 Using Common Form Controls 167 Saving Form Data with SharedPreferences eres TEEN aze WTS Summary 178 Q amp A 178 HOUR aihe Dialogs to Collect User Input xe 181 Working with Activity Dialogs 181 Using DatePickerDialog 184 Working with Custom Dialogs esses sssttnsssttnesneieessiee wu 187 Summary 194 Q amp A 194 HOUR 12 Adding Application Logic Riera nic tle RZ 197 Designing the Game Screen 197 Implementing the Game Screen Layout 200 Working with ViewSwitcher Controls siete fis ae wisi 203 Wiring Up Game Logic 208 Summary 214 OSTA O E E E E gc aed nna AS Workshop 215 Part Ill Enhancing Your Appl
51. Dialog Button click handler Make it display the message Clicked when the Button is clicked 2 Modify each EditText control to save its contents when the user presses the up key KEYCODE_DPAD_UP or down key KEYCODE_DPAD_DOWN on the direc tional keypad in addition to the Enter key KEYCODE_ENTER 3 Implement a Clear button that deletes all game preferences using the clear method of SharedPreferences Editor Don t forget to call the commit method This page intentionally left blank HOUR 11 Using Dialogs to Collect User Input What You ll Learn in This Hour Working with activity dialogs Using DatePickerDialog Handling and formatting date information Building custom dialogs v vV v V In this hour you complete the Been There Done That settings screen by adding several Dialog windows to QuizSettingsActivity Each Dialog window is specially designed to collect a specific type of input from the user First you add a Dialog window called DatePickerDialog to collect date input allowing the user to supply his or her date of birth and then you build a custom Dialog window to facilitate changing the user s password Working with Activity Dialogs An activity can use Dialog windows to organize information and react to user driven events For example an activity might display a dialog informing the user of an error or asking to confirm an action such as deleting a piece of information Using the Dialog mechani
52. Enter email adggess of friend fawn email com Creating an AsyncTask Subclass to Handle Friend Requests To send friend requests to the application server you need to add another AsyncTask subclass called FriendRequestTask to QuizSettingsActivity The FriendRequestTask class can be run using the execute method whenever the player inputs a friend s email address in the friend request dialog and presses OK The details of the FriendRequestTask class are very similar to those of the other AsyncTask subclasses you have written over the past few hours In the following example exception handling has been removed for clarity and brevity The only really interesting part to this new task is the friend request code within the doInBackground method Override protected Boolean doInBackground String params Boolean succeeded false String friendEmail params Q SharedPreferences prefs getSharedPreferences GAME_PREFERENCES Context MODE_PRIVATE Integer playerId prefs getInt GAME_PREFERENCES_PLAYER_ID 1 Vector lt NameValuePair gt vars new Vector lt NameValuePair gt vars add new BasicNameValuePair command add vars add new BasicNameValuePair playerId playerId toString vars add new BasicNameValuePair friend friendEmail HttpClient client new DefaultHttpClient HttpPost request new HttpPost T7TRIVIA_SERVER_FRIEND_EDIT request setEntity new UrlEncodedFormEntity vars Resp
53. External Launch HTTP Preview 6 J2EE Preview X l Filter matched 18 of 33 items Name DroidDebug 7 ElAndroid Target Common Project Launch Action Launch Default Activity Launch N Spk Do Nothing Apply Revert Gove Launching Android Applications Using the Emulator It s launch time and your droid is ready to go To launch the application you can simply click the Debug button from within the Launch Configuration screen or you can do it from the project by clicking the little green bug icon on the Eclipse toolbar Then select DroidDebug Debug Configuration from the list The first time you try to select DroidDebug debug configuration from the little green bug drop down you have to navigate through the configuration manager Future attempts will show this configuration for convenient use under the bug drop down 19 DiRwz FIGURE 1 5 The DroidDebug debug configura tion in Eclipse 20 FIGURE 1 6 An Android emu lator launching Screen Locked view FIGURE 1 7 The Droid 1 Android applica tion running in the emulator HOUR 1 Getting Started with Android After you click the Debug button the emulator screen will launch This can take some time so be patient You may need to click the Menu button on the emulator when you come to the Screen Locked view see Figure 1 6 Pa 642 Pa Android
54. Female Bc aa d Using Common Form Controls 173 Configuring Spinner Controls Most of the configuration for a Spinner control must be handled programmatically As with a ListView control a Spinner control uses a data adapter to map its con tents from a dataset to each view displayed in the control To load a Spinner control with data you follow these steps 1 Retrieve the Spinner control from the layout 2 Configure a data adapter to map the data to the control 3 Call the setAdapter method of the Spinner control To load the Spinner control from the layout you use the familiar findViewById method final Spinner spinner Spinner findViewById R id Spinner_Gender Next you configure your data adapter A Spinner control displays its data different ly when it s closed than when it s open Therefore you need to provide layout tem plates for both display states Fortunately the Android platform includes several spe cial layout resources to help create Spinner controls that contain text Specifically you can use the layout resource named android R layout simple_spinner_item to create the appropriate view for each item in a default Spinner control You can use the android R layout simple_spinner_dropdown_item layout resource as the drop down view resource template Using these handy built in layout templates you can load your String Array resource called genders into an ArrayAdapter control by using the
55. In this case the two strings are compared They should be equal The next test is to verify that editing the field actually updates the Shared Preferences value Add the following code to QuizSettingsActivity to test that this is true private static final String TESTNICK_KEY_PRESSES T E S T N I C K ENTER P aai public void testUpdateNickname Log w DEBUG_TAG Warning If nickname was previously testnick this test is invalid getActivity runOnUiThread new Runnable public void run nickname setText nickname requestFocus H sendKeys TESTNICK_KEY_PRESSES SharedPreferences settings getActivity getSharedPreferences QuizActivity GAME_PREFERENCES Context MODE_PRIVATE String fromPrefs settings getString QuizActivity GAME_PREFERENCES_NICKNAME assertTrue Prefs should be testnick fromPrefs equalsIgnoreCase testnick As before most of this is standard Android code that you should be familiar with However notice that this code is performing a couple calls on the UI thread This is required for these particular calls if you remove those calls from the UI thread the test case fails 378 itr FIGURE 22 3 Eclipse console output while running JUnit tests on Android Ott HOUR 22 Testing Android Applications To run an entire test method on the UI thread add the UiThreadTest annotation before your method implementation But note that this won t work in the
56. Now it s time to upload player information to the application server To do this you need to learn how to use the Apache HTTP client features available on the Android platform as well as how to add extra Apache libraries to the project Three features of the Been There Done That application need to upload data to the appli cation server gt QuizSettingsActivity This class needs to create a player record on the applica tion server and upload player settings information gt QuizGameActivity This class needs to upload the player s score gt QuizSettingsActivity This class needs to upload the avatar graphic 278 Oat HOUR 16 Adding More Network Support To enable the Been There Done That application to handle live data you need to access an application server as well as add networking functionality to the client Android application The full implementation of the networking code provided in this hour is available on the book s website http www informit com title 9 780321673350 Accessing Phone Status Information Some of the Been There Done That player settings will be uploaded to the applica tion server The application server needs to be able to determine which player or device it is communicating with Therefore the application uses the unique device identifier of each player s handset to differentiate between players To get this unique identifier you need to access information availabl
57. OnClickListener method avatarButton setOnClickListener new View OnClickListener Override public void onClick View v TODO Launch the Camera and Save the Photo as the Avatar H This should look familiar because you ve already implemented a number of listeners for Button controls Working with Image Media 223 Handling Long Clicks with setOnLongClickListener A long click is a special type of click available on the Android platform Basically a long click event is when a user clicks on a control for about one second This type of click is handled separately from a regular short click To handle long clicks you need to implement the View OnLongClickListener class and pass it into the ImageButton control s setOnLongClickListener method OnLongClickListener has one required method you must implement onLongClick Here is a sample implementation of OnLongClickListener for the avatar ImageButton control avatarButton setOnLongClickListener new View OnLongClickListener Override public boolean onLongClick View v TODO Launch Image Picker and Save Image as Avatar return false The onLongClick method looks much like the onClick method of the OnClickListener class However it has a return value which should be true if long click events are handled Try It Yourself v Take a moment to try out clicks and long clicks with an ImageButton control 1 Navigate to the QuizSettingsActivit
58. Signed Application Package Up until now you ve allowed Eclipse to handle the packaging and delivery of the application to handsets and emulators for debugging purposes Now you have the application release version sitting on your hard drive and you need to load it and test it Before installing the release version of your application on the emulator or hand set you should uninstall the debugging version completely You can do this on the handset or emulator from the Home screen by clicking Menu Settings Application Manage Applications choosing the application from the list clicking the Uninstall button and verifying that you want to uninstall the application Note that files or data in shared locations such as images stored in the gallery may be left behind Private files and data including preferences will be removed though The simplest way to manually install or uninstall an application package apk file on a handset or the emulator is to use the adb command line tool The following is the command for installing a package using adb adb install lt path_to_apk gt Testing the Signed Application Package 391 If there is only one device or emulator this command works However if you have multiple devices and emulators floating around you need to direct the installation command to a specific one You can use the devices command of the adb utility to query for devices connected to your computer adb de
59. Stark Refresh i Manager Q amp A 23 7 Double click one of the running Android devices There should be one listed for each handset plugged into the machine in addition to one for each emu lator instance running If you do not see the handset listed check your cables and make sure you installed the appropriate drivers as explained in Appendix A Eclipse now installs the Android application on the handset attaches a debugger and runs the application Your handset now shows a screen very similar to the one you saw in the emulator If you look at the DDMS perspective in Eclipse you see that logging information is available and many features of the DDMS perspective work with real handsets as well as the emulator New to Eclipse If you re still learning the ropes of the Eclipse development environment now is a great time to check out Appendix B Eclipse IDE Tips and Tricks Summary Congratulations You are now an Android developer You are starting to learn your way around the Eclipse development environment You created your first Android project You reviewed and compiled working Android code Finally you ran your newly created Android application on the Android emulator as well as on a real Android device Q What programming languages are supported for Android development A Right now Java is the only programming language fully supported for Android development Other l
60. The configured AVDs will be displayed as a list 3 Click the New button to create a new AVD 4 Choose a name for the AVD Because you are going to take all the defaults name this AVD VanillaAVvD 5 Choose a build target For example to support Android 2 1 choose the item build target called Android 2 1 API Level 7 from the drop down 6 Choose an SD card capacity in either kibibytes or mibibytes This SD card image will take up space on your hard drive so choose something reasonable such as a 1024MiB or less The minimum is 9MiB but keep in mind that the full size of the SD card is stored on your machine 18 Way FIGURE 1 4 Creating a new AVD in Eclipse HOUR 1 Getting Started with Android 7 Choose a skin This option controls the different visual looks of the emulator In this case go with the default HVGA screen which will display in portrait mode Your project settings should look as shown in Figure 1 4 8 Click the Create AVD button and wait for the operation to complete 9 Click Finish Because the Android Virtual Devices Manager formats the memory allocated for SD card images creating AVDs with SD cards may take a few moments Name VanillaAVD Target Android 2 1 API Level 7 M SD Card Size 1024 MiB O File __ Browse Skin Built in Default HVGA X Resolution x Hardware Property Value Abstracted LCD de 160 Delete
61. URL class as shown here URL xmlUrl new URL xmlSource Xm1PullParser questionBatch Xm1PullParserFactory newInstance newPullParser questionBatch setInput xmlUrl openStream null From here the parsing of the XML is unchanged because the XML format is the same and the Xm1ResourceParser used previously was derived from the Xm1PullParser class Because the parsing may take longer now you will move it off the main thread later in the hour Once you have the question batches and score data downloading from the remote server you can remove the mock XML resources from the project and the code that retrieves the XML resources If your application wants to retrieve and display web content you can use the WebView control which leverages the WebKit rendering engine to draw HTML content onscreen You can use the WebView control to display local or remote content Indicating Network Activity with Progress Bars Network enabled applications often perform tasks such as connecting to remote servers and downloading and parsing data These tasks take processing time and the user should be aware that these activities are taking place A great way to indi cate that an application is doing something is to show some sort of progress indica tor The Android SDK provides two basic styles of the ProgressBar control to handle determinate and indeterminate progress Indicating Network Activity with Progress Bars 263 Displayi
62. What software features will the application require Does the application support different screen orientations gt What Android SDK does the application require 334 HOUR 20 Developing for Different Devices While some of these decisions necessitate changes in the project libraries and the Android manifest file many can be handled using the same resource directory qual ifier strategy used for application internationalization Resource directories can be qualified to provide resources for a number of different application configurations see Table 20 1 You can apply these directory name qualifiers to the resource subdirectories such as res values Qualifiers are con catenated onto the existing subdirectory name in a strict order shown in prece dence order in Table 20 1 You can combine multiple qualifiers by separating them with dashes Qualifiers are always lowercase and a directory can contain only one qualifier of each type Custom qualifiers are not allowed TABLE 20 1 Important Resource Directory Qualifiers Directory Qualifier Type Values Comments Language Region locale Screen dimensions Screen orientation Screen pixel density Touch screen type Is keyboard available Are navigation keys available en fr es zh ja ko de and so on rUS rGB rFR rJP rDE and so on small normal large port land ldpi mdpi hdpi nodpi notouch stylus finger keysexposed keysh
63. a number of pixels or use a more flexible approach fill_parent or wrap_content Using fill_parent instructs a layout to scale to the size of the parent layout and using wrap_content shrink wraps the child View control within the parent giving it only the space of the child View con trol s dimensions A number of other interesting properties can be used to control specific layout behavior including margin settings and type specific layout attributes 116 FIGURE 7 2 Layout design for the Been There Done That splash screen HOUR 7 Implementing an Animated Splash Screen Let s use a TableLayout control to display some ImageView controls as part of the splash screen In the splash screen design you can use a vertical LinearLayout control to organize the screen elements which are in order a TextView control a TableLayout control with some TableRow control elements of ImageView controls and then two more TextView controls Figure 7 2 shows the layout design of the splash screen LinearLayout Vertical Orientation TableLayout 2 Rows 2 Columns ImageView ImageView splash1 png splash2 png ImageView ImageView splash3 png splash4 png TextView Version Info Adding New Project Resources Now that you have your layout design for the splash screen you need to create the string color and dimension resources to use within the layout You begin by adding four new graphic resources to the res draw
64. about the Twitter API at http apiwiki twitter com Working with the OpenSocial Initiative When you want to target more than one social networking site or reach as many end users as possible you ll want to look into the OpenSocial APIs http wiki opensocial org OpenSocial uses common APIs instead of site specific ones to integrate with many popular social applications and services including the following which are in alphabetic order gt friendster still popular in Southeast Asia gt hi5 popular in Europe and Central and South America gt Hyves popular in the Netherlands gt LinkedIn business networking gt Mail ru popular in Russia gt mixi popular in Japan gt MySpace popular in the United States and worldwide gt Netlog popular in Europe and the Middle East gt orkut popular in South America and India gt RenRen formerly Xiaonei popular with students in China gt Yahoo popular in the United States and worldwide gt XING business networking popular in Europe and China Each of these social networks has daily and monthly active users in the millions 302 HOUR 17 Adding Social Features Summary In this hour you learned how social features can be used to enhance the user expe rience of a mobile application You worked through a short example of how to add social features to the Been There Done That application by adding the ability for a user to specify friends by em
65. accompany this book These materials such as source code for many of the examples provided in the book are available online There are also a number of other online resources available for Android developers Accessing the Publisher s Website The source code that accompanies this book is available for download from the publisher s website see Figure C 1 http www informit com title 9780321673350 FIGURE C 1 The InformIT ry website Dy sere Darcey Shane Concer Pustaned 49 24 2000 ay Sama Pra ef te Sams Teac Yourser Hours genes ranuta onam m Dersiopment Adobo Reader y naw coman Lone Dorens sgh mt sma Ads To Uy Wish List Salb gys Descreten Sampie Contant Here s what you ll find on the publisher s website gt A thorough description of this book gt Downloadable source code 424 FIGURE C 2 The Android Mobile Application Development website APPENDIX C Supplementary Materials v Errata and book updates v InformIT users reviews of the book gt Sample content gt Other related books Accessing the Authors Website The authors book website at http androidbook blogspot com is a comprehensive guide for designing developing debugging and distributing Android applications see Figure C 2 gt fh amp Niipy androidbookblogspot com gt 0 efi Share Repot Abuse Next Bogs Create Beg Sipin ANDROID MOBILE APPLICATION DEVELOPMEN
66. agent Browse Ason pactag gt Ki ater restore Rewore needs appbcavon WESARH WA Attributes for DroidActiity Activity aa T The actully tag declares an andretdapp Activity chass that is avelatie as part of the package s anciecation components mm lmonementing a part of the application s iner eitertace Mame Using the Permissions Tab The Permissions tab see Figure 5 3 contains any permission rules required by the application This tab can also be used to enforce custom permissions created for the application 79 FIGURE 5 1 The Manifest tab of the Eclipse mani fest file resource editor FIGURE 5 2 The Application tab of the Eclipse mani fest file resource editor 80 FIGURE 5 3 The Permissions tab of the Eclipse manifest file resource editor Ott FIGURE 5 4 The Instrumentation tab of the Eclipse manifest file resource editor HOUR 5 Configuring the Android Manifest File File Edit Run Navigate Search Project Refactor Window Heip ori amp BEI 6 rOrQr BGr SEV a 5 Android Manifest Permissions 4 Permissions Attributes for android_permission CAMERA Uses Permission The lare peemnssiod tag requests a permission that the containing package must be granted in order for t to operate correctly Name android permission CAMERA android permission CAMERA Uses Permission Do not confuse the application Permission field a drop
67. and on devices Designing a Screen with Tabs Now you need to switch your focus to the QuizScoresActivity java file and wire up the controls needed by the TabHost control First you need to initialize the TabHost control and then you need to fill it with two tabs making the default tab the All Scores tab Finally you use mock score data to populate the TableLayout control in each tab Designing a Screen with Tabs 155 Configuring the TabHost Control The TabHost control must be initialized before it will function properly Therefore you first retrieve it by using the findViewById method Next you must call the TabHost control s setup method which initializes the TabHost and glues the specially named TabWidget and FrameLayout controls together to form a tab set as follows TabHost host TabHost findViewById R id TabHost7 host setup Adding Tabs to the TabHost Control Now that you have retrieved your TabHost control and initialized it you need to configure each tab using the addTab method This method takes a TabSpec parameter which describes the tab contents For example the following code creates the All Scores tab TabSpec allScoresTab host newTabSpec allTab allScoresTab setIndicator getResources getString R string all_ scores getResources getDrawable android R drawable star_on allScoresTab setContent R id ScrollViewAllScores host addTab allScoresTab The TabSpec con
68. application to allow a player to enter friends email addresses There are a number of ways you could go about doing this of course You could add a new activity and update the menu screen allowing for a whole new screen in the application or you could just update the settings screen with a new area To keep things simple you can just add a new section at the bottom of the settings screen that acts much like the other settings that rely on a dialog see Figure 17 1 293 Way 294 FIGURE 17 1 The settings screen updated to allow for friend requests Password 4 Password Set Birth Date SS F April 06 2018 Gender 4 Female v r Favorige Place MountWashington New Hampshire Friends si Pick a Place Add a new fri nd by email For example you could add the following just below the favorite place layout controls lt TextView android id tid TextView_Friend_Email android layout_width wrap_content android layout_height wrap_content android text string settings_friend_email_label android textSize dimen help_text_size android textStyle bold gt lt TextView gt lt LinearLayout android id id LinearLayout_Friend_Email android orientation horizontal android layout_height wrap_content android layout_width fill_parent gt lt Button android id id Button_Friend_Email android layout_width wrap_content android layout_height
69. as part of the Eclipse plug in perform the following steps 1 In Eclipse right click the appropriate application project and choose the Export option 2 Under the Export menu expand the Android section and choose Export Android Application Packaging and Signing an Application 389 3 Click the Next button 4 Select the project to export The one you right clicked before is the default 5 On the keystore selection screen choose the Create New Keystore option and enter a file location where you want to store the key as well as a password for managing the keystore If you already have a keystore choose browse to pick your keystore file then enter the correct password Make sure you choose strong passwords for the keystore Remember where the Watch keystore is located too The same one is required to publish an upgrade to your ut application If its checked in to a revision control system the password will help protect it but consider adding an extra layer of privilege required to get to it 6 Click the Next button 7 On the Key Creation screen enter the details of the key as shown in Figure 23 3 in EEE FIGURE 23 3 Exporting an Key Creation 3 Android applica tion using the Eclipse plug in Alias BeenThereDoneThatAlias Password evccecsccees i Confirm awhvawauawue Validity years 30 First and Last Name Anthony E Stark Organizational Unit And
70. at the top level of any Android project The Android system uses the information in this file to do the following gt Install and upgrade the application package gt Display application details to users gt Launch application activities 78 Dw HOUR 5 Configuring the Android Manifest File gt Manage application permissions gt Handle a number of other advanced application configurations including act ing as a service provider or content provider If you use Eclipse with the ADT plug in for Eclipse the Android project wizard will create the initial AndroidManifest xml file with default values for the most important configuration settings You can edit the Android manifest file by using the Eclipse manifest file resource editor or by manually editing the XML The Eclipse manifest file resource editor organizes the manifest information into categories presented on five tabs gt Manifest gt Application gt Permissions v Instrumentation gt AndroidManifest xml Using the Manifest Tab The Manifest tab see Figure 5 1 contains package wide settings including the package name version information and minimum Android SDK version informa tion You can also set any hardware configuration requirements here Using the Application Tab The Application tab see Figure 5 2 contains application wide settings including the application label and icon as well as information about application compo ne
71. be the normal launch activity of the Been There Done That application Note that any activity could be launched such as the high scores but this one makes the most sense When you create a dynamic App Widget individual views could have their own PendingIntent objects assigned This way the actions they send cause an updateAppWidget method call to change the look of the App Widget in response to the click Working with Widget Background Operations You might think that because the App Widget doesn t run within the application process you don t have to worry about operations taking too long You might also think that because the App Widget is a BroadcastReceiver object it will automatical ly perform its actions in the background In both cases you d be wrong For lengthy operations the general solution is to launch a separate thread to handle things However for App Widgets this isn t feasible Instead you must create and launch an Android Service instance and then from the service you can launch a background thread An Android service can provide two useful operations It can provide background processing and it can provide an interface to a remote object such as providing access to extensions or software libraries Working with Widget Background Operations 315 Why can t a Thread class be used directly from an App Widget Although the full details are beyond the scope of this book the simple answe
72. begin to imple ment each activity later in the book Running the Game Prototype You are almost ready to run and test your application But first you need to create a debug configuration for your new project within Eclipse 108 FIGURE 6 8 The prototype for Been There Done That in the application drawer HOUR 6 Designing an Application Framework Creating a Debug Configuration You need to create a debug configuration for each project within Eclipse Be sure to set the preferred AVD for the project to one that is compatible with the Google APIs API Level 7 If you do not have one configured or are unsure simply click the Android SDK and AVD Manager button in Eclipse From here you can determine which AVDs are appropriate for the application and create new ones as necessary Launching the Prototype in the Emulator It s time to launch the Been There Done That application in the Android emulator You can do this by using the little bug icon in Eclipse or by clicking the Run button on the debug configuration you just created As you can see in Figure 6 8 the application does very little so far It has a pretty icon which a user can click to launch the default activity QUizSplashActivity This activity displays its TextView control informing you that you have reached the splash screen There is no real user interface yet for the application and you still need to wire up the transitions between the different activitie
73. calendars android permission READ CALENDAR android permission WRITE_CALENDAR Changing general phone android permission SET ORIENTATION settings android permission SET_TIME_ZONE android permission SET WALLPAPER Making calls android permission CALL_PHONE android permission CALL_PRIVILEGED Sending and receiving android permission READ SMS messages android permission RECEIVE_MMS android permission RECEIVE_SMS android permission RECEIVE_WAP_PUSH android permission SEND_SMS android permission WRITE_SMS Using network sockets android permission INTERNET Accessing audio settings android permission RECORD AUDIO android permission MODIFY_AUDIO_ SETTINGS Accessing network settings android permission ACCESS NETWORK_STATE android permission CHANGE_NETWORK_STATE Accessing Wi Fi settings android permission ACCESS WIFI_STATE android permission CHANGE_WIFI_STATE Accessing phone hardware android permission BLUETOOTH android permission CAMERA android permission FLASHLIGHT android permission VIBRATE android permission BATTERY_STATS Account services android permission GET_ ACCOUNTS android permission MANAGE_ACCOUNTS Summary 91 Permission Category Useful Permissions Synchronization android permission READ_SYNC_SETTINGS android permission READ_SYNC_STATS android permission WRITE_SYNC_SETTINGS For a complete list of the permissions used by Android applications see the android Manifest permission class documentation Some permissions ar
74. can use the TelephonyManager class to retrieve information about the phone user s voice mail For example you access the voice mail number by using the getVoiceMailNumber method Retrieving Network Roaming Information You ve already seen how to access roaming information from the networking servic es found in Hour 15 Adding Network Support You can also determine whether the subscriber service is roaming by using the isNetworkRoaming method of the TelephonyManager class This is not necessarily a reliable method for determining whether a user will be charged extra for data or phone calls but you can consider it a hint that the user might be charged depending on the user s service plan However an application could use this information to prompt the user to choose whether to allow network usage when roaming with a message such as Your handset appears to be roaming Would you like to continue Retrieving Other Telephony Status Information The TelephonyManager class also has many other methods for determining fine grained device telephony status information See the Android SDK documentation for more details Uploading Data to a Remote Application Server 281 You can use the SmsManager class android telephony SmsManager and the Did you__ SmsMessage Class android telephony SmsMessage to send SMS messages ow Uploading Data to a Remote Application Server In Hour 10 Building Forms to Colle
75. children and handles transition from the currently visible child view to the next view to be displayed The child View controls of a ViewSwitcher control can be generated programmatically using ViewFactory 204 ow HOUR 12 Adding Application Logic There are two subclasses of the ViewSwitcher class gt TextSwitcher A ViewSwitcher control that allows swapping between two TextView controls gt ImageSwitcher A ViewSwitcher control that allows swapping between two ImageView controls Although a ViewSwitcher control only ever has two children it can display any number of View controls in succession ViewFactory generates the content of the next view such as the ImageSwitcher and TextSwitcher controls for iterating through the question images and text You can create a custom switcher by implementing your own subclass of the ViewSwitcher class Using ViewFactory to Generate ViewSwitcher Views When you create a ViewSwitcher control you can configure ViewFactory using the setFactory method ViewFactory has one required method the makeView method This method must return a View of the appropriate type For example ViewFactory for TextSwitcher should return a properly configured TextView whereas ViewFactory for ImageSwitcher would return ImageView Here is an implementation of a ViewFactory control for an ImageSwitcher control that you could use to generate each question graphic on the game play screen priv
76. clicking and holding on the tab the title itself and dragging it to a new location such as the vertical sec tion on the right side of the Eclipse window This provides the much needed vertical space to see the dozens of properties often found there You can experiment to find a tab layout that works well for you Each perspective has its own layout too and the perspectives can be task oriented If you completely mess up a perspective or just want a clean start you can simply choose Window Reset Perspective Integrating Source Control Eclipse has the ability to integrate with many source control packages through add ons This allows Eclipse to manage checking out a file making it writable when you first start to edit a file checking a file in updating a file showing a file s status and a number of other tasks depending on the support of the add on Common source control add ons are available for CVS Subversion Perforce git and many other packages Generally speaking not all files are suitable for source control For Android projects any file with the bin and gen directories shouldn t be in source control To exclude these generically within Eclipse go to Preferences Team Ignored Resources Add apk ap_ and dex by clicking the Add Pattern button and adding one at a time This page intentionally left blank APPENDIX C Supplementary Materials A number of supplementary materials have been developed to
77. configuration 108 designing activity requirements 96 97 creating new project 103 game screen features 102 help screen features 98 99 high level game features 96 main menu screen features 98 scores screen features 100 settings screen features 100 101 splash screen features 97 98 launching in emulator 109 project resources adding 103 104 providers See content providers ProviderTestCase2 class 380 proximity sensor 362 publishing on Android Market billing 404 developer account benefits 402 explained 395 removing applications 402 return policy 401 402 signing up for developer account 396 397 uploading applications 397 400 release process 383 385 packaging and signing 387 390 preparing release candidate build 385 386 testing packaged application 390 392 testing release candidate 386 387 self distribution 402 403 to other marketplaces 404 405 publishProgress method 265 269 putExtra method 51 putint method 176 putString method 176 Q question batches downloading and parsing 271 272 dismissing progress dialog 273 handling background processing 273 starting progress dialog 272 lt question gt element 201 questions declaring string literals for question parsing 209 storing in hashtable 210 lt questions gt element 201 QuizActivity class 96 QuizGameActivity class 97 277 QuizHelpActivity class 97 QuizMe
78. dif ferent default settings for display purposes including themes and styles Make sure you run your application on all target platforms prior to release Your application will likely behave and display slightly differently on each device Screen characteris tics are major design factors to consider when developing user interfaces You can create specific AVD profiles to mimic the behavior of specific screen char Did you acteristics in the emulator using the Android SDK and AVD Manager ow 340 IOUR 20 Developing for Different Devices Figure 20 5 shows how the same layout might appear different on different screens On the left we have a generic medium density HVGA screen and on the right we have the Motorola Droid which has a high density WVGA854 screen Note the rather marked differences FIGURE 20 5 A layout may display different ly on different devices Have you eVer b en n an African Safari Don t despair though Fixing these sorts of problems is straightforward Some ways to prevent display problems associated with screen density and the like in the first place include the following gt Only set attributes you require no unnecessary settings to maintain gt Keep all dimension values in a dimension value resource file not in individ ual layout files gt Specify font sizes in dp or sp as opposed to pt Configuration Management for Android 341 gt Specify pixel dimension
79. displaying a static image such as a JPEG a live wallpaper can dis play anything that can be drawn on a surface using the full graphical capabilities of the device and the Android SDK as described in the section on 2D and 3D graph ics we discussed earlier in this hour A live wallpaper is similar to an Android Service but its result is a surface that the host can display You can create a live wallpaper as complex as you like but hand set responsiveness and battery life should be taken in to account Some examples of live wallpapers include gt A 3D display showing an animated scene portraying abstract shapes gt A service that animates between images found on an online image sharing service gt An interactive pond with water that ripples with touch gt Wallpapers that change based on the actual season weather and time of day To learn more about how to implement live wallpapers see the article on live wall By the papers at the Android documentation site http bit ly bngiaP and the Cube Live ay Wallpaper sample application included with the Android SDK 358 HOUR 21 Diving Deeper into Android Managing and Sharing Data You are already familiar with some of the ways applications can store data persistently gt They can store simple primitive data types within SharedPreferences at the application and activity levels gt They can store data on a remote application server Applications can also
80. example shown here because the sendKeys method can t be run on the main thread You get the This method cannot be called from the main application thread exception error Instead just portions of the test can be run on the UI thread as shown Running Automated Tests Now that your tests are written you need to run them to test your code There are two ways of doing this The first method is the most straightforward and provides easy to read results right in Eclipse You simply select Debug Debug As Android JUnit Test The Console view of Eclipse shows the typical installation progress for both the test application and the application being tested see Figure 22 3 If the test project is not selected Eclipse may try to run a regular application as a JUnit test application resulting in a bunch of warnings and errors To avoid this problem right click on the project name in the Package Explorer pane of Eclipse choose Debug As and then choose Android JUnit Test Alternately you can go to the Debug Configurations menu double click on Android JUnit Test to create a new test configuration and then fill in the details With the LogCat view you see the normal Android debug output as well as new out put for the tests that are performed In this way you can better debug problems or errors that result from failures or even find new failures that should be tested for The JUnit view though may be the most u
81. for 396 397 explained 395 language support 405 locales 326 327 removing applications from 402 return policy 401 402 uploading applications to 397 400 Android mascot 8 Android Mobile Application Development website 424 425 Android NDK 23 Android Plug in for Eclipse ADT installing 412 413 Android Project command New menu 10 Android Project Wizard 10 11 Android SDK defining 343 detecting programmatically 343 installing 10 explained 411 Linux installations 412 Mac OS X installations 412 Windows installations 411 setting minimum Android SDK version 83 specifying target SDK 342 upgrading 413 versions 341 342 Android Virtual Devices See AVDs Android Wireless Application Development 73 251 364 android bluetooth package 363 android database package 359 android database sqlite package 359 android gesture package 352 android graphics package 355 android media package 353 android provider package 360 android sax package 72 android service wallpaper package 357 android speech Recognizer Intent 353 android speech tts package 352 android util Xml package 72 AndroidManifest xml file 12 15 activities designating launch activity 87 88 registering 86 87 92 application permissions managing 88 92 application settings configuring linking secondary libraries 82 naming Android packages 82 naming applications 84 providing applica
82. for portrait mode the default and one for landscape mode The full layout implementation for the landscape mode changes and handset differences discussed in this hour is available on the book s website http www informit com title 9780321673350 First let s review the design of the existing game xml layout file shown in Figure 20 2 Configuration Management for Android TRIVIA QUESTION In landscape mode you just don t have enough vertical space for the ImageView TextView and Button controls To streamline this layout for landscape mode you might consider putting the TextView control to the right of the ImageView control You could also modify the size of the graphic or the buttons if you needed to The same controls with the same names are defined in both versions of the layout file they re just rearranged in the landscape version see Figure 20 3 TRIVIA QUESTION HERE The resulting screen looks much nicer when you switch to landscape mode as shown in Figure 20 4 337 FIGURE 20 2 The game screen design default layout version FIGURE 20 3 The game screen design custom land scape layout version 338 FIGURE 20 4 The game screen in land scape mode landscape specific layout used un ra Developing for Different Devices Because screen orientation changes cause the current activity to be restarted any processing tasks such as image decoding
83. get results for places called East Springfield or Springfield by the Sea for example For the best results choose the geocoding address that is the most specific for example use Springfield s zip code instead of its name to resolve the coordinates Like other network operations geocoding services are blocking operations This means that you ll want to put any calls to geocoding services in a thread separate from the main UI thread Using Geocoding Services 247 Using Geocoding Services with Android The Android SDK includes the Geocoder android location Geocoder class to facilitate interaction with the handset s geocoding and reverse geocoding services if they are present Instantiating a Geocoder is simple Geocoder coder new Geocoder getApplicationContext When you have a valid Geocoder you can begin to use any geocoding or reverse geocoding services available on the device Geocoding Translating Addresses into Coordinates You can use the Geocoder class getFromLocationName method to resolve a loca tion into coordinates This method takes two parameters the string containing the location information and the number of results you want returned For example the following code looks up Springfield and limits the number of results to three String strLocation Springfield List lt Address gt geocodeResults coder getFromLocationName strLocation 1 You can iterate through the Geocoder results
84. getSystem to retrieve the global system Resource object Then you can call the getString method with the appropriate string resource name like this String confirm Resources getSystem getString android R string ok To reference a system resource from another compiled resource such as a layout file use the following format android resource type resource name For example you could use the system string for ok by setting the appropriate string attribute as follows android string ok Working with Simple Resource Values Simple resources such as string color and dimension values should be defined in XML files under the res values project directory in XML files These resource files use special XML tags that represent name value pairs These types of resources are compiled into the application package at build time You can manage string color and dimension resources by using the Eclipse By the Resource editor or you can edit the XML files directly ay 64 Way HOUR 4 Managing Application Resources Working with Strings You can use string resources anywhere your application needs to display text You tag string resources with the lt string gt tag and store them in the resource file res values strings xml Here is an example of a string resource file lt xml version 71 0 encoding utf 8 gt lt resources gt lt string name app_name gt Name this App lt string gt lt string n
85. gives you the nice effect of each ImageView spinning into existence in a cascading fashion Stopping LayoutAnimationController animations is no different from stopping individual animations You simply use the clearAnimation method The addi tional lines to do this in the existing onPause method are shown here Summary 123 TableLayout table TableLayout findViewById R id 7TableLayout07 for int i 0 i lt table getChildCount i TableRow row TableRow table getChildAt i row clearAnimation Handling Animation Life Cycle Events Now that you are happy with your animations you just need to make QuizSplashActivity transition to QUizMenuActivity when the animations are complete To do this you create a new Intent control to launch the QuizMenuActivity class and call the startActivity method You should also call the finish method of QuizSplashActivity because you do not want to keep this activity on the stack that is you do not want the Back button to return to this screen Of your animations the fade_in2 animation takes the longest at 5 seconds total This animation is therefore the one you want to trigger your transition upon You do so by creating an AnimationListener object which has callbacks for the animation life cycle events start end and repeat In this case only the onAnimationEnd method has an interesting implementation Here is the code to create the AnimationListener and implement the on
86. go to the Instrumentation section you see the text of the label rather than the name Adding More Tests Now you have all the tools you need to add more unit tests to your application The Android SDK includes a variety of classes that can be implemented for performing a wide range of tests specific to Android Among these are the following gt ActivityUnitTestCase Similar to the example testing in the preceding sec tion in that it tests on Activity but at a lower level This class can be used to unit test specific aspects of an activity such as how it handles onPause when it has called onFinished and so on This is a great way to test the life cycle of an activity gt ApplicationTestCase Like ActivityUnitTestCase this class allows testing of Application classes in a fully controlled environment 380 HOUR 22 Testing Android Applications gt ProviderTestCase2 Performs isolated testing on a content provider gt ServiceTestCase Performs isolated testing on a service In addition to these test case objects there are helper classes for providing mock objects that is objects that aren t the real ones but can be used to better trace calls to the real objects helper classes for simulating touch screen events and other such utilities You can find full documentation on these classes in the android test package Summary In this hour you learned about the many different ways in which an Android appli c
87. graphic to 36x36 pixels and place it in the res drawable 1dpi directory This is the icon for low pixel density screens 6 Set the android icon property to the resource name of your new icon drawable myicon This will pick one of the three graphics you created based on the pixel density of the handset or emulator that the application is running on The end result will be the same graphic found in three differently sized files in three different resource directories Typically a graphic may be further optimized for each resolution A Providing an Application Description The lt application gt tag android description attribute is a string representing a short description of the application You can set this name to a string resource lt application android label My application name android description string app_desc gt The Android system and application marketplaces use the application description to display information about the application to the user Setting Debug Information for an Application The lt application gt tag android debuggable attribute is a Boolean value that indi cates whether the application can be debugged using a debugger such as Eclipse You will not be able to debug your application until you set this value You will also want to reset this value to false before you publish your application Setting Other Application Attributes There are a number of other settings on the Application ta
88. hand set if a handset is plugged in Launching Android Applications on a Handset It s time to load your application onto a real handset To do this you need to plug a handset into your computer using the USB data cable To ensure that you debug using the correct settings follow these steps 1 2 In Eclipse choose Run Debug Configurations Double click DroidDebug Debug Configuration On the Target tab set Deployment Target Selection Mode to Manual You can always change it back to Automatic later but choosing Manual will force you to choose whether to debug within the emulator and choose an AVD ora device if one is plugged in whenever you choose to debug Apply your changes by clicking the Apply button Plug an Android device into your development computer using a USB cable Click the Debug button within Eclipse A dialog Figure 1 9 appears showing all available configurations for run ning and debugging your application All physical devices are listed as are existing emulators that are running You can also launch new emulator instances by using other AVDs you have created la D E racc owa E O Select a device compatible with target Android 2 1 Choose a running Android device Serial Number AVD Name Target Debug State E 0403699212 N A 21 updatel Online Launch a new Android Virtual Device AVD Name Target Name Platform API Level Details VanillaAVD Android 2 1 21 7
89. handsets These handsets are useful for general development and testing but may not be suitable for final testing on actual target handsets because some functionality may be limited and the firmware version may be different than that found on consumer handsets Exploring Other Android Publishing Options The Android platform is an open platform and publishing options are also very open You ve learned how to publish on the Android Market but there are other options available as well You might want to take advantage of these alternatives to target handsets and devices that do not come with the Android Market distribute handsets to a narrower target audience distribute applications that don t comply with the Android Market rules or simply control distribution on your own There are alternative markets for Android devices such as the ARCHOS 5 Internet Tablet Applications developed especially for these types of devices are generally but not always marketed separately from applications developed for Android handsets Selling Your Application on Your Own Site You can distribute Android applications directly from your own website or server This method is most appropriate for vertical market applications content compa nies developing mobile marketplaces and big brand websites wishing to drive users to their branded Android applications It can also be a good way to get beta feed back from end users Although self distri
90. has a number of methods for retrieving important information about the network state including whether the network is available connected and roaming boolean isMobileAvail netInfo isAvailable boolean isMobileConn netInfo isConnected boolean isRoamingConn netInfo isRoaming The NetworkInfo class also has many other methods for determining fine grained network status information These can be read about in the documentation Checking Server Availability Programmatically Even if a network is available and connected there is no guarantee that the remote server you want to communicate with is accessible from the network However ConnectivityManager has a handy method called requestRouteToHost that allows you to attempt to validate traffic using a given network type for example mobile network Wi Fi and IP address is possible Using HTTP Networking The most common network transfer protocol is Hypertext Transfer Protocol HTTP Most commonly used HTTP ports are open and available for use on phone networks 262 ow HOUR 15 Adding Network Support A fast way to get to a network resource is by retrieving a stream to the content Many Android interfaces for reading data accept streams One such example is XmlPullParser The setInput method of Xm1PullParser class takes an InputStream Previously you retrieved this stream from the resources Now howev er you can get it from a network resource using the simple
91. input HOUR 10 Building Forms to Collect User Input Working with EditText Controls The EditText control which is derived from the TextView control is used to collect textual input from the user Figure 10 3 shows a simple EditText control This is an input field Configuring EditText Controls All the typical attributes of a TextView control for example textColor textSize are available to EditText controls The following are some EditText attributes that are commonly used for the settings screen gt inputType Instructs the Android system about how to help the user fill in the text For example you set the inputType attribute of the EditText control for the Email field to textEmailAddress which instructs the Android system to use the email oriented soft keyboard with the sign The inputType value called textPassword automatically masks the user s password as it is typed gt minLines and maxLines Restrict the number of lines of text allowed in the control gt maxLength Restricts the number of characters of text allowed in the control For example you can limit the number of characters allowed in the Nickname setting by setting the maxLength attribute of the Nickname setting s EditText control to 20 Handling Text Input As with a TextView control you can access the text stored in an EditText control by using the getText and setText methods For example to extract the string typed into the Edit
92. intent action called ACTION_PICK that allows the user to choose from a set This type of intent is often used in conjunction with a URI but it need not be This kind of intent can also be used to create a set of all data of a given MIME type on the handset and allow the user to choose an item from the set For example you can create an intent to use within the onLongClick method to display all images to the user as follows Intent pickPhoto new Intent Intent ACTION_PICK pickPhoto setType image startActivityForResult pickPhoto TAKE_AVATAR_GALLERY_REQUEST When you run the application and long click the avatar ImageButton control a gallery of images available on the device is displayed see Figure 13 5 FIGURE 13 5 Choosing an image from the gallery on the Android emulator 228 wash HOUR 13 Working with Images and the Camera The ACTION_PICK Intent action causes a gallery of all images stored on the hand set to launch allows the user to choose one image and returns a URI address to the image s location Therefore within a specific case statement of the onActivityResult method for the request code TAKE_AVATAR_GALLERY_REQUEST you can retrieve the URI by inspecting the Intent parameter called data as follows Uri photoUri data getData Then to convert the Uri to a valid Bitmap object you can use the following method Bitmap galleryPic Media getBitmap getContentResolver photoUri
93. is already stored on the handset Designing the Avatar Feature Many mobile applications today are networked and have some social component One way for users to differentiate themselves from others is by setting custom icons to represent who they are To give users this ability you can implement the avatar feature on the set tings screen Avatars come in many forms an avatar may be a close up photograph of the user s face or it might be a funky graphic that speaks to the user s personality To incorporate of the avatar feature into the Been There Done That Settings screen you need to modify the screen design slightly to include the graphic as well as some mecha nism by which the user can change the graphic Figure 13 1 shows a rough design of how the avatar feature will be incorporated into the settings screen 218 FIGURE 13 1 Rough design for the Been There Done That avatar feature HOUR 13 Working with Images and the Camera AVATAR NICKNAME Picture 20 characters max EMAIL Will be used as unique account id PASSWORD Password requires entering twice to verify BIRTH DATE DOB requires entering Month Day Year GENDER Male Female or Prefer Not To Say Space is at a premium in a mobile application and you want to keep the settings screen for the Been There Done That application as easy to use as possible The avatar feature has two requirements The user must be able to set the ava
94. is any ambiguity in the name of a class during automatic import such as with the Android Log class Eclipse prompts you with the package to import 416 APPENDIX B Eclipse IDE Tips and Tricks Finally you can configure Eclipse to automatically organize the imports each time you save a file This can be set for the entire workspace or for an individual project Configuring this for an individual project allows better flexibility when you re work ing on multiple projects and don t want to make changes to some code even if they are an improvement To configure this perform the following steps 1 Right click the project and choose Properties 2 Expand Java Editor and choose Save Actions 3 Check Enable Project Specific Settings Perform the Selected Actions on Save and Organize Imports Documenting Code Regular code comments are useful when done right Comments in Javadoc style appear in code completion dialogs and other places thus making them even more useful To quickly add a Javadoc comment to a method or class simply press Ctrl Shift J in Windows or Cmd Alt J on a Mac Alternatively you can choose Source Generate Element Comment to prefill certain fields in the Javadoc such as parameter names and author thus speeding up the creation of this style of com ment Using Auto Complete Auto complete is a great feature that speeds up text entry If this feature hasn t appeared for you yet or has gone away you can br
95. is the explosion of new Android devices on the market This problem called handset fragmentation makes the task of keeping track of the devices available running the different ver sions of the Android SDK and having different screen sizes features and hardware increasingly complex see Figure 22 1 372 HOUR 22 Testing Android Applications FIGURE 22 1 Handset frag mentation Managing a Handset Database It is a good idea to use a database to keep track of handset information for develop ment testing and marketing purposes Such a database might contain information such as the following gt Handset information models features SDK versions hardware specifics such as whether a handset has a camera or built in keyboard gt Which handsets you have on hand and where they are if they are owned or loaned and so on gt Which handsets you want to target for a given application gt The handsets on which your applications are selling best Testing on the Emulator A test team cannot be expected to set up testing environments on every carrier or in every country where users will use an application There are times when using the Android emulator can reduce costs and improve testing coverage The following are some of the benefits of using the emulator gt Rapidly testing when a target handset is not available or is in short supply gt Simulating handsets when they are not yet available for example p
96. made dialog types available for use in addition to the basic dialog These are AlertDialog CharacterPickerDialog DatePickerDialog ProgressDialog and TimePickerDialog You can also create an entirely custom dialog by designing an XML layout file and using the Dialog setContentView method To retrieve controls from the dialog layout you simply use the Dialog findViewById method Logging Application Information Android provides a useful logging utility class called android util Log Logging messages are categorized by severity and verbosity with errors being the most severe Table 3 3 lists some commonly used logging methods of the Log class TABLE 3 3 Commonly Used Log Methods Method Purpose Log e Logs errors Log w Logs warnings Log i Logs informational messages Log d Logs debug messages Log v Logs verbose messages Excessive use of the Log utility can result in decreased application performance Debug and verbose logging should be used only for development purposes and removed before application publication The first parameter of each Log method is a string called a tag One common Android programming practice is to define a global static string to represent the overall application or the specific activity within the application such that log filters can be created to limit the log output to specific data For example you could define a string called TAG as follows private static final Stri
97. of users are using Android SDK 2 1 This data was collected and provided online by the Android developer website dur ing the two weeks prior to April 4 2010 You can check for updated statistics at the following Android developer website http developer android com resources dashboard platform versions html One particularly interesting factor is that some versions of the SDK are effectively skipped by most devices such as 2 0 because they are quickly replaced and updates like 2 0 1 and 2 1 are pushed out to users This data can be invaluable for reducing testing load to just platforms where it matters 342 Oat HOUR 20 Developing for Different Devices It may not be feasible for certain phones especially older models to receive the lat est firmware updates As you can see if you want to hit the broadest range of users you may need to develop for several different versions of the SDK This data can be invaluable for reducing the testing load to only those platforms where it matters Looking for new data watching the market news and surveying your target users will all ultimately help you determine which devices to target Choosing an Application s Target Platform To appeal to the most users you need to give some thought to your target platform before you develop any Android application Will your application support some of the older more established handsets or just the newest ones Do some market research and determi
98. phone settings for the emulator such as application management sound and display settings and localization Dev Tools application Built in application to configure configure development tool settings fed amp a Using Emulator Skins Emulator features such as screen size screen orientation and whether the emulator has a hardware or soft keyboard are dictated by the emulator skin The Android SDK supports a number of different skins which emulate various handset screen resolutions the default being HVGA The specific skins available depends on the target build platform Determining the appropriate skin is part of the AVD configuration process Using SD Card Images with the Emulator To save data with the emulator there must be an SD card image configured For example you must have a properly configured SD card image to save media files like camera graphics and sound files to the emulator The most convenient way to create SD card images for use with the emulator is to create them as part of the AVD process as you did in Hour 1 SD card images should be at least 9 MiB Using Other Android Tools Although we ve already covered the most important tools a number of other special purpose utilities are included with the Android SDK gt Android Hierarchy Viewer Allows developers to inspect application user interface components such as View Properties while the application is running Summary 39
99. process is essential for a successful Android proj ect This is especially true for any application that plans to support multiple Android SDK versions handsets or languages To perform regular versioned builds do the following Testing Best Practices 369 gt Use a source control system to keep track of project files gt Version project files at regular intervals and perform builds gt Verify through testing that each build performs as expected There are many wonderful source control systems out there for developers and most that work well for traditional development will work fine for a mobile project Many popular source control systems such as Perforce Subversion and CVS work well with Eclipse Because of the speed at which mobile projects tend to progress iterative develop Did you__ ment processes are generally the most successful strategies for mobile develop ow ment Rapid prototyping gives developers and quality assurance personnel ample opportunities to evaluate an application before it reaches users Using a Defect Tracking System A defect tracking system provides a way to organize and keep track of application bugs called defects and is generally used along with a process for resolving these defects Resolving a defect generally means fixing the problem and verifying that the fix is correct in a future build With mobile applications defects come in many forms Some defects occur on all ha
100. question public static final String XML_TAG_QUESTION_ATTRIBUTE_NUMBER number public static final String XML_TAG_QUESTION_ATTRIBUTE_TEXT text public static final String XML_TAG_QUESTION_ATTRIBUTE_IMAGEURL imageUr1 While you are at it you can also define the default batch size to simplify allocation of storage for questions while parsing the XML public static final int QUESTION_BATCH_SIZE 15 Storing the Current Batch of Questions in a Hashtable Now within the QuizGameActivity class you can implement a simple helper class called Question to encapsulate each trivia question private class Question int mNumber String mText String mImageUr1 public Question int questionNum String questionText String questionImageUrl mNumber questionNum mText questionText 210 ow HOUR 12 Adding Application Logic mImageUrl questionImageUrl You will not be storing all the questions locally Instead you fetch a batch of ques tions at a time for now from local mock XML files later from the web You need a place to store these questions so declare a Hashtable member variable within the QuizGameActivity class to hold a batch Question objects in memory after you have parsed a batch of XML Hashtable lt Integer Question gt mQuestions The Android SDK includes many commonly used Java classes For example you ll find many familiar data structures Such as Hashtable and utility classes in the java
101. ready to publish 392 HOUR 23 Getting Ready to Publish Summary In this hour you learned how to prepare an application for publication Specifically you learned about the steps to take to verify that your application is ready for publi cation such as stripping debugging information and verifying application configu ration settings You then learned to export an unsigned application package file generate a private key and digitally sign the application for publication Q amp A Q Will the release process described in this hour work for any Android applica tion marketplace A Generally speaking yes We have focused on the Android Market require ments For details on the requirements imposed by other marketplaces see those specific developer programs Typically any differences are in the require ments imposed on the application s Android manifest file and the specifics of the digital signature that accompanies the application Q Why must the key be valid until October 22 2033 A The digital signature of an application may persist through various applica tion upgrades By enforcing a date far in the future trust relationships between the application provider and third parties including users can be established and maintained for the long term Q Can I programmatically obtain information about an application package A Yes you can use the getPackageInfo method of the PackageManager class to obtain info
102. resource hierarchy In this hour we review the most common types of resources used by Android applications how they are stored and how they can be accessed programmatically Using Application and System Resources Resources are broken down into two types application resources and system resources Application resources are defined by the developer within the Android project files and are specific to the application System resources are common resources defined by the Android platform and accessible to all applications through the Android SDK You can access both types of resources at runtime You can also access resources from within other compiled resources such as XML layout files to define attributes of specific controls 60 HOUR 4 Managing Application Resources Working with Application Resources Application resources are created and stored within the Android project files under the res directory Using a well defined but flexible directory structure resources are organized defined and compiled with the application package Application resources are not shared with the rest of the Android system Storing Application Resources Defining application data as resources is a good programming practice Grouping application resources together and compiling them into the application package has the following benefits gt Code is cleaner and easier to read leading to fewer bugs gt Resources are organized by type and guaran
103. run into cases where a referenced view is undefined in one orientation Workshop Quiz 1 True or False The following is a correctly qualified resource directory name res drawables ruUS en 2 For which of the following handset configurations can resources be defined A Language and region locale B Input methods such as keyboards touch screens and navigation keys C Screen size resolution and orientation D Whether the keyboard and navigation keys are hidden E All of the above Answers 1 False The region must follow the language Therefore the directory would appropriately be named res drawables en rus 2 E All these qualifiers are available for application resources There are also others For a complete list see the list at the Android developer website http developer android com guide topics resources resources i18n html AlternateResources Workshop 345 Exercises 1 Test the Been There Done That application on a handset Change to land scape mode and ensure that all screens of the application display correctly Add landscape specific layout resources where needed the splash screen and game play screen at a minimum 2 Compile the Been There Done That application for a variety of target SDK versions and test them on handsets or the emulator with the appropriate AVD This page intentionally left blank HOUR 21 Diving Deeper into Android What You l Learn in This Hour gt Ex
104. scores gt An explanation of the game rules gt A way to store game settings You also need a way to transition between these different features One way to do this is to create a main menu screen that the user can use to navigate the applica tion features Reviewing the requirements we find that we need six primary screens within the Been There Done That application They are the following gt A startup screen gt A main menu screen gt A game play screen gt A settings screen gt A scores screen gt A help screen These screens will make up the core user interface for the application Determining Activity Requirements Each screen of the Been There Done That application will have its own Activity class Figure 6 1 shows the six activities required one for each screen A good design practice is to implement a base Activity class with shared compo nents which we ll simply call QuizActivity You will employ this practice as you define the activities needed by the Been There Done That game gt QuizActivity Derived from android app Activity this is the base class Here you will define application preferences and other application wide set tings and features gt QuizSplashActivity Derived from QuizActivity this class represents the splash screen Designing an Android Trivia Game 97 gt QuizMenuActivity Derived from QuizActivity this class represents the main menu screen gt QuizHelpActi
105. settings 208 209 game screen 102 adding resources to 200 202 designing 197 200 updating layout of 202 203 help screen 98 99 adding resources to 145 146 designing 144 raw resource files 147 148 updating layout of 146 high level game features determining 96 internationalization 325 326 launching in emulator 109 main menu 98 adding project resources 131 designing 127 130 layout requirements 129 ListView control 129 134 137 screen headers building with RelativeLayout 129 updating layouts 132 133 network support See network applications options menus adding resources to 138 139 adding to activities 139 handling menu selections 140 project resources adding 103 104 scores screen 100 adding resources to 151 152 completed scores screen 157 delays in loading 158 designing 149 layout requirements 150 TabHost control 150 155 updating layout of 152 154 settings screen 100 101 adding resources to 165 166 Button controls 170 172 designing 161 163 EditText controls 168 170 index more useful Email us at indexes samspublishing com 434 Been There Done That application SharedPreferences 175 178 Spinner controls 172 174 updating layout of 166 167 splash screen 97 98 adding resources to 116 117 animation 119 123 designing 113 114 Layout controls 114 116 updating layout of 117 119 ViewSwitcher contro
106. state permissions 278 index raw files 72 73 strings 64 XML files 72 accounts Android Market developer accounts benefits 402 signing up for 396 397 ACTION_CHOOSER intent 226 ACTION_IMAGE_CAPTURE intent 225 226 230 ACTION_VIEW intent 248 activities activity requirements determining 96 97 adding options menus to 139 callback methods 49 50 designating launch activity 87 88 explained 47 implementing for Been There Done That game 105 106 launching 48 49 managing state 49 preferences 110 428 activities registering 86 87 92 saving state 50 51 activity dialogs See dialogs lt activity gt tag 86 87 ActivityUnitTestCase class 379 adb Android Debug Bridge 39 391 addresses translating 247 addTab method 155 addTextChangedListener method 169 ADT Android Development Tools Android Project Wizard 10 11 installing 412 413 overview 9 afterTextChanged method 191 AIDL Compiler 39 AlertDialog 182 alerting users with notifications 348 349 AndAppStore 404 anddev org 425 Android Asset Packaging Tool aapt 39 Android Debug Bridge adb 39 391 Android developer program 8 9 Android developer website 364 425 Android Development Tools ADT See ADT Android documentation 27 29 Android Hierarchy Viewer 38 Android Market 8 425 billing 401 developer account benefits 402 developer accounts benefits 402 signing up
107. store and share data by doing the following gt They can leverage the file and directory structure on the device to store private application files in any format gt They can store structured data in private SQLite databases gt They can access data within other applications that act as content providers gt They can share internal application data by becoming content providers You already know how to work with SharedPreferences and how to store data on a network application server so let s talk about other ways of managing and shar ing data Working with Files and Directories Each Android application has its own private application directory and files You can use the standard java file I O package called java io to manipulate files and directories Android application files are stored in a standard directory hierarchy on the Android file system Android application data is stored on the Android file system in the following top level directory data data lt package name gt Several special purpose subdirectories are created beneath the top level application directory to store databases preferences and files You can also create private direc tories and files here as needed using the appropriate methods of the application s Context object The following are some of the important file and directory manage ment methods of the Context class gt openFileInput Opens an application file for reading in the fil
108. t you worry because we ll just tell you again tomorrow Acknowledgments This book would never have been written without the guidance and encouragement we received from a number of very patient and supportive people including our editorial team coworkers friends and family Throughout this project our editorial team at Pearson Sams Publishing was top notch Special thanks go to Trina MacDonald Olivia Basegio and Betsy Harris Our fantastic tech nical reviewer Jonathan Jackson helped us ensure that this book provides true correct and high quality technical information Finally we d like to thank many of our friends and family members who supported us during some difficult times when we needed to make our book deadlines despite a very serious family illness that required us to write the book from Grandma s kitchen table Yes you can develop Android apps anywhere We would like to specifically single out Liz Reid Guy Grayson the Lenz family especially Thomas and Patrick Shoshi Brown and family especially Jacob the Badger family especially Wi Vi and Nolia Richard deCastongrene Asher Siddiqui Anthony Shaffer Spencer Nassar and Mary Thompson for their support and encouragement xvi We Want to Hear from You As the reader of this book you are our most important critic and commentator We value your opinion and want to know what we re doing right what we could do better what areas you d like to see us publis
109. target handsets getVoiceMailNumber identifying and acquiring 371 method 280 testing on 373 isNetworkRoaming method 280 target platforms choosing 342 temperature sensor 362 Test Application Project Wizard 375 testing applications 40 automated testing 373 adding more tests 379 380 creating test cases 375 377 creating test projects 374 375 explained 374 logging application information 374 running automated tests 378 379 best practices 367 368 coding standards 368 defect tracking system 369 regular versioned builds 368 369 test plans 369 370 on emulator 372 feasibility testing 373 managing test environment device fragmentation 371 372 handset databases 372 target handsets 371 network applications on emulator 258 on hardware 259 packaged applications 390 392 release candidate 386 387 on target handsets 373 test cases creating 375 377 test environment managing device fragmentation 371 372 handset databases 372 target handsets 371 test plans 369 370 test projects creating 374 375 types of testing 370 text converting speech to 353 text input handling in EditText controls 168 TTS text to speech 352 TextSwitcher controls 205 TextView control 133 themes 349 350 Thread class 266 315 time internationalization 330 TimePickerDialog 182 TimeUtils class 330 title attribute lt item gt element 138 tools See spe
110. the parts of the date day month and year You can use this feature of the Calendar class to configure DatePickerDialog with a specific date 185 ow 186 HOUR 11 Using Dialogs to Collect User Input The onPrepareDialog method passes in both the Dialog identifier and the instance of the Dialog window so you can modify it as needed For example in this case you want to update the date of DatePickerDialog so you use the updateDate method Override protected void onPrepareDialog int id Dialog dialog super onPrepareDialog id dialog switch id case DATE_DIALOG_ID Handle any DatePickerDialog initialization here DatePickerDialog dateDialog DatePickerDialog dialog int iDay iMonth iYear Check for date of birth preference if mGameSettings contains GAME_PREFERENCES_DOB Retrieve Birth date setting from preferences long msBirthDate mGameSettings getLong GAME_PREFERENCES_DOB 0 Time dateOfBirth new Time dateOfBirth set msBirthDate iDay dateOfBirth monthDay iMonth dateOfBirth month iYear dateOfBirth year else Calendar cal Calendar getInstance Today s date fields iDay cal get Calendar DAY_OF_MONTH iMonth cal get Calendar MONTH iYear cal get Calendar YEAR Set the date in the DatePicker to the date of birth OR to the current date dateDialog updateDate iYear iMonth iDay return Launching DatePickerDialog You have configur
111. the gallery the ImageButton control contents will be updated with the appropriate graphic as shown in Figure 13 6 Password _ j Set Password No Password et Birth Date Pick Date No Date Set tua Gender Prefer Not To Say Scaling Bitmap Graphics You can use the createScaledBitmap method of the Bitmap class to generate thumbnails and such Make sure to calculate the destination height and width appropriately to retain the original bitmap image s aspect ratio Otherwise the scaled graphic will be stretched and shrunk in odd ways which lessens its appeal Generating Bitmap Graphics from Various Sources You can use the BitmapFactory class android graphics BitmapFactory to decode bitmap objects from various sources including files byte arrays streams and resources 229 FIGURE 13 6 The Been There Done That set tings screen with a custom avatar 230 HOUR 13 Working with Images and the Camera Performing Bitmap Image Transformations You can perform various image transformations such as rotation operations on bitmap objects by using the Matrix class android graphics Matrix This class manages a 3x3 image matrix that can be used for image translations Summary In this hour you implemented a new avatar feature on the Been There Done That settings screen The user can set an avatar by taking a picture with the built in cam era or by choosing an existing image fr
112. the geo fix command 243 FIGURE 14 8 Setting the location of the emulator to Yellowstone National Park with DDMS FIGURE 14 9 Setting the loca tion of the emu lator to Yellowstone National Park Oitow 244 HOUR 14 Adding Support for Location Based Services Accessing the Location Based Services To access the LBS service on an Android device you must have the appropriate per missions Location based services cannot be used by an Android application unless it is granted the appropriate lt uses permission gt settings configured in the Android manifest file The most common permissions used by applications leveraging LBS are android permission ACCESS_FINE_LOCATION and android permission ACCESS __ COARSE_LOCATION To use the GPS provider you use android permission ACCESS_FINE_LOCATION When you have registered the appropriate permission you can access the LocationManager class by using the getSystemService method as follows LocationManager locMgr LocationManager getSystemService LOCATION_SERVICE The LocationManager class allows you to access the LBS functionality available on the device Working with Providers There may be any number of LBS providers for a device You can get a list of all providers by calling the getProviders method of the LocationManager class You can limit the providers returned to only those that are enabled or you can provide criteria for returning only provi
113. to Collect User Input Assume that you added to the strings xml resource file the following three gender resource strings defined earlier lt string name gender_male gt Male lt string gt lt string name gender_female gt Female lt string gt lt string name gender_neutral gt Prefer Not To Say lt string gt Within the arrays xml resource file you set each item in the genders string array to the appropriate string resource For example the first Item element in the array with an index of 0 would have the value string gender_neutral The resulting arrays xml resource file follows lt xml version 7 0 encoding utf 8 gt lt resources gt lt string array name genders gt lt item gt string gender_neutral lt item gt lt item gt string gender_male lt item gt lt item gt string gender_female lt item gt lt string array gt lt resources gt Save the arrays xml resource file Now when you want to load the genders string array resource into memory you can access it programmatically by using the R array genders resource identifier Updating the Settings Screen Layout The settings xml layout file dictates the user interface of the settings screen Again you open the Eclipse layout resource editor and remove all existing controls from the layout You then follow these steps to generate the layout you want based on your earlier design 1 Add the customary LinearLayout control with its background attrib
114. to your Droid1 project Within the layout file change the textSize attribute of the TextView control to the dimension resource you just created Rerun the application and view the result 3 Add a new drawable graphics file resource to your Droid1 project Within the layout file add an ImageView control and set its src attribute to the drawable resource you just created Rerun the application and view the result 4 Add a raw text file resource to the Droid1 project Use the openRawResource method to create an InputStream object and read the file Output the con tents of the file to the log by using the Log v method Rerun the application and view the result HOUR 5 Configuring the Android Manifest File What You l Learn in This Hour Exploring the Android manifest file Configuring basic application settings Defining activities Managing application permissions Managing other application settings v vv v v Every Android project includes a special file called the Android manifest file The Android system uses this file to determine application configuration settings including the applica tion s identity as well as what permissions the application requires to run In this hour we will examine the Android manifest file in detail and look at how different applications use its features Exploring the Android Manifest File The Android manifest file named AndroidManifest xml is an XML file that must be included
115. tricks guides and pointers to other resources http androidbook blogspot com 366 HOUR 21 Diving Deeper into Android Exercises 1 Think of three different ways a local SQLite database could be used to enhance the Been There Done That application 2 Review the various system services that can be requested by using the getSystemService method The various services are defined in the android content Context class 3 Review the Been There Done That application and identify three functional areas where you could design and use custom View controls What would those custom controls do 4 Many Android applications have the same look because they rely on the default theme provided by the platform Add theme definitions to the layout screens in the Been There Done That application This way the application will have a custom look that will be consistent across Android devices regard less of what their default theme is HOUR 22 Testing Android Applications What You l Learn in This Hour gt Best practices for testing mobile applications gt Developing a mobile test framework gt Handling other testing concerns Every mobile developer dreams of developing a killer app Many people think that if they could just come up with a great idea they d be home free Wrong The truth is any one can come up with a great idea The trick is to act on the idea with a clear vision a concise pitch to users
116. user int startingNumber ProgressDialog pleaseWaitDialog Once you ve implemented the QuizTask class you can update the onCreate method of the QuizGameActivity class to call the QuizTask class s execute method when the screen first loads The execute method takes two parameters the server web address for question downloads and the starting question number an Integer for the batch to download public static final String TRIVIA_SERVER_QUESTIONS TRIVIA_SERVER_BASE questions jsp LE aan QuizTask downloader new QuizTask downloader execute TRIVIA_SERVER_QUESTIONS startingQuestionNumber Starting the Progress Dialog Now you need to implement the onPreExecute method This is the perfect place to display a progress dialog that tells the user that the trivia questions are being downloaded The user won t be able to do anything until the questions are down loaded Although you put the indicator in the title bar when downloading the scores earlier you want to put the progress dialog over the game screen Override protected void onPreExecute pleaseWaitDialog ProgressDialog show QuizGameActivity this Trivia Quiz Downloading trivia questions true true pleaseWaitDialog setOnCancelListener new OnCancelListener public void onCancel DialogInterface dialog QuizTask this cancel true Although we ve used hardcoded strings here for clarity a well written application would use string reso
117. using the LogCat utility provided with the Android SDK Don t forget to strip any diagnostic information such as logging information from the application before publication Logging information and diagnostics can nega tively affect application performance Automated Testing with JUnit and Eclipse The Android SDK includes extensions to the JUnit framework for testing Android applications Automated testing is accomplished by creating test cases in Java code that verify that the application works the way you designed it This automated test ing can be done for both unit testing and functional testing including user interface testing This discussion is not meant to provide full documentation for writing JUnit test cases For that look to online resources such as http www junit org or books on the subject Some people follow a paradigm of creating the test cases first and then writing code that causes the test cases to pass This method can work well in an envi ronment where all application results and behavior are known before coding begins and will change little or not at all Automated testing for Android involves just a few straightforward steps 1 Create a test project 2 Add test cases to the new project 3 Run the test project The following sections walk you through how to perform each of these steps to test a specific feature of the Been There Done That settings screen Creating the Tes
118. wrap_content android text string settings_button_friend_email gt lt Button gt lt TextView android layout_width fill_ parent android layout_height fill_ parent android textSize dimen help_text_size android textStyle bold android gravity center android id t id TextView_Friend_Email_Tip android text string settings_friend_email_tip gt lt TextView gt lt LinearLayout gt Adding Friend Support to Your Application 295 Like other settings on this screen the layout updates involve adding several TextView labels and a Button control called Button_Friend_Email Clicking this button will launch a new dialog Therefore you need to add a new layout resource to describe the dialog layout see Figure 17 2 FIGURE 17 2 Explode Outline Preview of the friend request dialog layout Editing config default Devices ADP2 Y contig Landscape closed v Localel A Theme x I Create Enter email adggess of friend Layouts A AbsoluteLayout O DialerFilter E ExpandableListView G FrameLayout G GridView HorizontalScrollView Views GestureOverlayView SurfaceView view vViewstub AnalogClock autocom pleteTextView Layout friend_entry xml This layout should be defined as follows in the XML layout file called res layout friend_entry xml lt xml version 7 0 encoding utf 8 gt
119. you can simply right click the item you want to rename and then choose Refactor Rename Alternatively after selecting the item you can press Ctrl Alt R in Windows or Cmd Alt R on a Mac to begin the renam ing process If you are renaming a top level class in a file the filename will have to be changed as well Eclipse usually handles the source control changes required to do this if the file is being tracked by source control 418 APPENDIX B Eclipse IDE Tips and Tricks If Eclipse can determine that the item is in reference to the identically named item being renamed all instances of the name will be renamed as well Occasionally this even means comments are updated with the new name Quite handy Formatting Code Eclipse has a built in mechanism for formatting Java code Formatting code with a tool is useful for keeping the style consistent applying a new style to old code or matching styles with a different client or target such as a book or an article To quickly format a small block of code select the code and press Ctrl Shift F in Windows or Cmd Shift F on a Mac The code is formatted to the current settings If no code is selected the entire file is formatted Occasionally you need to select more code such as an entire method to get the indentation levels and brace matching correct The Eclipse formatting settings are found in the Properties pane under Java Code Style Formatter You can configure these settings o
120. yourself with the XML layout file format Switch to the XML view frequently and accustom yourself to the XML generated by each type of control Do not rely on the Eclipse layout resource editor alone 69 FIGURE 4 2 The layout resource editor in Eclipse 70 Dw HOUR 4 Managing Application Resources Try It Yourself Give the Eclipse Layout editor a spin 1 2 Open the Droid1 Android project you created earlier Navigate to the res layout main xml layout file and double click the file to open it in the Eclipse layout resource editor Switch to the Layout tab and you should see the layout preview in the main window The two most important tabs for the layout resource editor are the Outline tab and the Properties tab If you drag the Properties tab up to the right side of the Eclipse Java perspective you can simultaneously view the main layout resource editor in the middle of the screen the Project Explorer to the left the Properties tab to the right to fully use the vertical space it needs and Outline mode along the bottom which is usually shorter and doesn t need the vertical space of the Properties tab Click the Outline tab This outline is the XML View hierarchy of this layout file In this case you have a LinearLayout control If you expand it you see that it contains a TextView control Select the TextView control on the Outline tab You see a red box highlight this control
121. 04 monitoring battery life 363 multimedia 353 audio 353 supported formats 364 video 354 MultipartEntity class 288 multiple App Widgets 319 naming Android packages 82 applications 84 network applications accessing network services HTTP networking 261 262 network permissions 260 network status checking 260 261 accessing phone status information retrieving telephony information 279 280 setting phone state permissions 278 asynchronous tasks with AsyncTask class 265 266 with threads and handlers 266 designing application servers 256 257 explained 255 256 progress bars 257 guidelines 257 258 progress bars indicating network activity with 262 determinate progress 263 indeterminate progress 263 progress dialogs 263 264 question batches download ing and parsing 271 272 dismissing progress dialog 273 handling background processing 273 starting progress dialog 272 scores downloading and displaying 267 background processing 268 269 cancellation 270 271 progress indicator 268 270 progress updates 269 270 ScoreDownloaderTask class 267 testing on emulator 258 on hardware 259 447 notifications uploading data to servers determining data to send 277 278 explained 281 with HTTP GET method 282 285 with HTTP POST method 286 288 network permissions 260 network roaming information retrieving 280 network services acc
122. 147 148 specifying default resources 325 language specific resources 325 region specific resources 326 storing 74 strings accessing 64 adding to Been There Done That game 104 explained 64 formatting 64 system resources definition of 59 documentation for 74 referencing 63 storing 63 XML resources retrieving 156 responsive applications 367 REST representational state transfer 300 results launching activities for 48 retrieving color resources 65 shared preferences 107 108 XML files 156 return policy Android Market 401 402 reverse geocoding 247 RingtoneManager class 356 ringtones 356 running automated tests 378 379 tasks asynchronously with AsyncTask class 265 266 with threads and handlers 266 S sandboxes 386 saveAvatar method 225 228 saving activity state 50 51 bitmaps 228 229 settings to SharedPreferences 176 shared preferences 107 SAX parser 74 scaling bitmaps 229 230 lt score gt element 152 ScoreDownloaderTask class 267 scores See also scores screens downloading and displaying 267 background processing 268 269 cancellation 270 271 progress indicator 268 270 progress updates 269 270 ScoreDownloaderTask class 267 uploading 285 scores screens adding resources to 151 152 completed scores screen 157 defining features of 100 delays in loading 158 designing 149 layout requirements 150 TabHost control
123. 352 UserDictionary content provider 360 users alerting with notifications 348 349 identifiers 302 informing about network activity 257 lt uses library gt tag 82 lt uses permission gt tag 88 lt uses sdk gt tag 83 vV v method Log class 54 values folder 16 variables renaming 417 418 verifying applications 391 392 versioning applications 82 83 video 354 Videos tab Android documentation 28 VideoView control 354 View controls 350 ViewFactory class 204 205 ViewGroup controls 350 viewing log information 35 views animating all views in layout 122 123 animating specific views 121 122 custom views 350 ViewSwitcher controls 203 204 generating with ViewFactory 204 205 ImageSwitcher 206 207 TextSwitcher 205 virtual devices See AVDs Android Virtual Devices voice mail information retrieving 280 Ww w method Log class 54 wallpaper 356 357 WallpaperManager class 356 websites anddev org 425 Android developer website 364 425 Android Market 425 Android Mobile Application Development website 424 425 Developer com 426 FierceDeveloper 425 InformIT 423 424 JUnit 380 Open Handset Alliance 425 OpentIntents 425 Stack Overflow Android 426 Wireless Developer Network 426 Wi Fi 363 widget xml file 308 widgets See App Widgets WifiManager object 363 Windows Android SDK installation 4141 device debugging configuration
124. 39 handling menu selections 140 MessageDigest class 285 Messaging application 37 methods addTab 155 addTextChangedListener 169 afterTextChanged 191 assertTrue 377 bindService 317 clearAnimation 122 123 commit 212 compress 228 contains 177 containsKey 210 create 193 createChooser 226 createFromResource 173 createScaledBitmap 229 creating 415 d Log class 54 deleteFile 359 dismiss 264 dismissDialog 53 183 184 dolnBackground 265 268 273 283 285 297 e Log class 54 execute 267 298 fileList 359 findViewByld 54 147 155 171 173 191 finish 51 format 187 fromFile 228 GET 282 285 getActivity 376 getApplicationContext 46 getAssets 74 getAttributeValue 157 getBestProvider 244 getCacheDir 359 getCallState 279 getColor 65 getConfiguration 329 getDeviceld 279 getDimension 66 getDir 359 getDrawable 67 getFilesDir 359 getFromLocation 247 getFromLocationName 247 getintent 51 getLastKnownLocation 245 445 methods getLatitude 245 getLongitude 245 getNetworkinfo 261 getNetworkType 279 getOwnerActivity 194 getPackagelnfo 392 getPhoneType 279 getPreferences 50 110 getProvider 244 getQuestionImageDrawable 206 getQuestionImageUrl 207 getResources 62 74 getSharedPreferences 46 110 getSimOperator 280 ge
125. 8 POST 286 288 processScores 269 publishProgress 265 269 putExtra 51 putint 176 putLong 176 putString 176 removeDialog 53 183 184 192 194 renaming 417 418 requestLocationUpdates 245 requestRouteToHost 261 saveAvatar 225 228 setAdapter 173 setContentView 54 268 setCurrentTabByTag 155 setCurrentText 205 207 setEntity 288 setFactory 204 setiImageBitmap 221 setImageDrawable 206 207 221 setiImageResource 221 setiImageURI 206 215 221 222 setiImageViewBitmap 311 setlmageViewResource 311 setInAnimation 207 setinput 262 269 273 setintent 140 setLayoutAnimation 122 setNegativeButton 192 setOnClickListener 141 171 setOnClickPendingIntent 314 setOnltemClickListener 135 141 setOnltemSelectedListener 174 setOnKeyListener 169 setOnLongClickListener 223 setProgress 263 setSelection 141 173 setText 147 168 205 207 setTextViewText 311 setTheme 350 setTitle 192 setup 155 376 showDialog 53 183 186 193 194 startActivity 48 51 123 startActivityForResult 49 52 224 startAnimation 122 startService 317 stopSelf 317 stopSelfResult 317 stopService 318 tearDown 376 updateAppWidget 311 314 updateDate 186 v Log class 54 w Log class 54 minimum Android SDK version setting 83 mksdcard utility 39 MobiHand 4
126. 8 6 BHU a o e The DDMS per CGO Sz SM 7 2S mes 9 Hea O Alocation Tracer Fie apere s spective in nave Sae Dace Time Permon hie i 2i woaatel ome 7020 04 06 URL omen Eclipse Vaewi aVO 2 1 detug 0t PcomanecicbockdodLapk 13296 2010 04 06 1902 wr comandioidbook d apo orvate ate gt ancara gt au 70100406 LAL dwowe s Gorros 2010 04 06 1840 oraw ow 2020 04 06 1840 crwerver x gt on towns 2020 04 06 IAO araras gt mac 2020 04 06 2840 west propery 2020 04 06 IA Gwe omen 2010 04 06 1902 armarwar s ew 1970 01 01 0000 dimra Smm A09 OOS ormara kcoming mambec 5551712 voce a sus Venne Tha a an SAIS Menage 10 the emas 0000 7 e 04 06 19 09 04 06 19220 04 06 19 20 04 06 19210 04 08 19 40 Fitter The DDMS perspective can be used to monitor application processes as well as interact with the emulator You can simulate voice calls and send SMS messages to the emulator You can send a mock location fix to the emulator to mimic location based services You will learn more about DDMS and the other tools available to Android developers in Hour 2 Mastering the Android Development Tools 22 FIGURE 1 9 The Eclipse dia log for choosing an application deployment target HOUR 1 Getting Started with Android The LogCat logging tool is displayed on both the DDMS perspective and the Debug Perspective This tool displays logging information from the emulator or the
127. 88 launching activities 48 49 Android applications with emulator 19 21 109 on handset 22 23 with intents 52 53 248 249 dialogs 183 custom password dialog 193 DatePickerDialog to 186 187 Layout controls 114 116 layout folder 15 Layout Resource Editor 68 70 Layoutinflater class 71 layouts accessing programmatically 71 adding to Been There Done That game 104 App Widgets 308 creating custom layout for landscape mode 335 337 designing with Layout Resource Editor 68 70 with XML 69 explained 67 68 favorite place feature 234 235 favorite place dialog 236 237 help screens 146 game screens 202 203 Layout controls 114 116 main menu screens adding TextView template layout 133 layout requirements 129 ListView control 129 130 updating master layouts 132 133 password dialog 190 RelativeLayout control 129 scores screens 150 154 settings screens 166 167 splash screen layouts 117 119 443 listen method LBS Location Based Services 352 accessing last known location 245 providers 244 enabling location testing on emulator 241 243 favorite place feature designing 233 234 dialog 235 237 implementing framework for 237 240 layout updates 234 235 geocoding services 246 247 guidelines for 240 241 maps launching map applications with intents 248 249 working with Google APIs 250 251 receiving location updates 245 libr
128. 92 293 privacy concerns 302 social networking services integrating Android applications with explained 300 Facebook support 300 301 OpenSocial initiative 301 other social network applications 303 Twitter support 301 supporting player relation ships 292 tailoring to application 292 types of 291 social networking services integrating Android applications with explained 300 Facebook support 300 301 OpenSocial initiative 301 other social network applications 303 Twitter support 301 social trivia game See Been There Done That application software piracy protecting against 406 source control integrating with Eclipse 421 source files editing 416 417 Source menu commands Override Implement Methods 415 space requirements 410 speech converting text to 352 converting to text 353 speech recognition 353 Spinner controls 172 configuring 173 handling Spinner selections 173 174 listening for selection events 174 splash screens adding resources to 116 117 animation adding to splash screens 120 121 animating all views in lay out 122 123 animating specific views 121 122 handling animation life cycle events 123 performance issues 124 types of 119 120 defining features of 97 98 designing 113 114 Layout controls 114 116 updating layout of 117 119 SplashActivity class 44 SQLite databases 359 src folder 12 stable applications 367 Stack Overfl
129. AdSense Understanding the Android Market Application Return Policy Although it is a matter of no small controversy the Android Market has a 24 hour refund policy on applications That is to say a user can use an application for 24 hours and then return it for a full refund As a developer this means that sales aren t final until after the first 24 hours However this only applies to the first down load and first return If a particular user has already returned your application and wants to try it again he or she must make a final purchase and can t return it a second time Although this limits abuse you should still be aware that if your appli cation has limited reuse appeal or if all its value can come from just a few hours or less of use you might find that you have a return rate that s too high and need to pursue other methods of monetization 402 Dwr HOUR 24 Publishing on the Android Market Removing Your Application from the Android Market You can use the unpublish action in your developer account to remove an applica tion from the Android Market The unpublish action has an immediate effect but may take a few moments to become unavailable across the entire system Using Other Developer Account Benefits Having a registered Android developer account enables you to manage your appli cations on the Android Market In addition if you have a developer account you can purchase development versions of Android
130. AnimationEnd callback Animation fade2 AnimationUtils loadAnimation this R anim fade_in2 fade2 setAnimationListener new AnimationListener public void onAnimationEnd Animation animation startActivity new Intent QuizSplashActivity this QuizMenuActivity class QuizSplashActivity this finish Now if you run the Been There Done That application again either on the emula tor or on the handset you see some nice animation on the splash screen The user then transitions smoothly to the main menu screen which is the next screen on your to do list Summary Congratulations You ve now implemented the first screen of the Been There Done That trivia quiz In this hour you designed a screen and then identified the appro priate layout and View components needed to implement your design After you included the appropriate resources you were able to configure the splash xm1 lay out file Finally you added some tweened animations to the screen and then han dled the transition between QuizSplashActivity and QuizMenuActivity 124 HOUR 7 Implementing an Animated Splash Screen Q How well does the Android platform perform with regard to animation A The Android platform has reasonable performance with animations However it is very easy to overload a screen with animations and other controls For example if you were to place a VideoView control in the middle of the screen with all the animations you might see d
131. By launching the Contacts application and allowing the player to choose a contact D By allowing the player to input a friend s phone number 3 True or False The Android SDK has built in support for social networking sites such as Facebook Twitter and MySpace 304 HOUR 17 Adding Social Features Answers 1 False Adding social features to an application can enhance the experience for users but this is a design decision that requires thought and planning Some types of applications benefit greatly from these features while others may not Add social features to an application only when doing so provides a clear ben efit to both users and the developer 2 B Players can add friends in the Been There Done That application by inputting their email addresses The application server tries to match each email address entered to an existing player If the player exists then a friend relationship is established 3 False You can use the networking features of the Android SDK to access the developer APIs provided by third party social networking sites such as Facebook Twitter and MySpace Exercises 1 Modify the Scores of Friends tab of the scores screen to display each friend s avatar as well as each score Hint The URL for each friend s avatar is includ ed in the XML score data downloaded from the application server 2 Modify the scores screen to add another tab showing the scores of players who have added this play
132. C fi http marketandroid com publish Home EOr gt O countries to Vabhanng oppone export your application to f Tiarna Daars ae Ll veme Seemee ateate eet onda aumsa imas tanas Emne Demay pna i UU The following is some of the information you must enter on this form gt Application title and description in several languages English is the default language gt Countries locations where the application will be published These loca tions are subject to export compliance laws so choose your locations carefully As of this writing nearly 50 locations are available and new locations are being added regularly In addition you can choose specific carriers for each location to further limit application distribution Alternatively you can choose All Locations to include any future locations supported by the market For a complete list of locations where Android applications can be sold or published for free see http market android com support bin answer py hl en amp answer 138294 gt Application type and category Spend the time to set these fields appropri ately as defined by the Android Market so that your application reaches its intended audience Incorrectly categorized applications do not sell well gt Application price The Android Market currently supports only one pricing model single payment No subscription model pricing exists yet within the Android Market You m
133. Compositor Gloria Schurick Contents at a Glance THRO GU CHOW cee ses sze cesses es ta aes EA RAEE I OR EO A A a a Part I Android Fundamentals HOUR 1 Getting Started with Android E E E ci eer an T 2 Mastering the Android elope TOOS E 27 3 Building Android Applications ccc 43 4 Managing Application Resources ett OD 5 Configuring the Android Manifest File oot Z7 6 Designing an Application Framework ooo occ 9S Part Il Building an Application Framework HOUR 7 Implementing an Animated Splash Screen oo 113 8 Implementing the Main Menu Screen deaa LA 9 Developing the Help and Scores Screens eaa 143 10 Building Forms to Collect User Input 00cc LOL 11 Using Dialogs to Collect User Input es 181 12 Adding Application LOGIC 2 octets LOT Part Ill Enhancing Your Application with Powerful Android Features HOUR 13 Working with Images and the Camera a EE E Le 14 Adding Support for Location Based Services e 233 15 Adding Network Support ccce LOD 16 Adding More Network Support inisini 277 17 Adding Social Features i E A DOL 18 Creating a Home Screen App Widget Keepin ennn Part IV Adding Polish to Your Android Application HOUR 19 Internationalizing Your Application ee B21 20 Developing for Different Devices oot SOS 21 Diving Deeper into Android SAT 22 Testing Android Applications o oo ccc SOT iv Teach Yourself Android Application Development in 24 Hours Part V Publishing Your Applicati
134. D nme uD 12308 208 G 3 WEALTH poan 123555 Implementing Application Functionality Now that you understand how a typical Android application might be designed you re probably wondering how to go about implementing that design We ve talked about how each activity has its own user interface defined within a separate layout resource file You might be wondering about implementation hur dles such as the following gt How do I control application state gt How do I save settings gt How do I launch a specific activity 46 waai HOUR 3 Building Android Applications With our theoretical game application in mind it is time to dive into the implemen tation details of developing an Android application A good place to start is the application context Using the Application Context The application context is the central location for all top level application function ality You use the application context to access settings and resources shared across multiple activity instances You can retrieve the application context for the current process by using the getApplicationContext method like this Context context getApplicationContext Because the Activity class is derived from the Context class you can use this instead of retrieving the application context explicitly You might be tempted to just use your Activity context in all cases Doing so can lead to memory leaks though The sub
135. Dismissing the Progress Dialog Next you implement the onPostExecute method Now that the background pro cessing has taken place you can just drop in the code you originally used to display the screen This is also the perfect place to dismiss the progress dialog Override protected void onPostExecute Boolean result Log d DEBUG_TAG Download task complete if result displayCurrentQuestion startingNumber else handleNoQuestions pleaseWaitDialog dismiss For the full code to the implementation please see the sample code provided on By the this book s website ay 274 HOUR 15 Adding Network Support Summary In this hour you modified the Been There Done That application to download data including the quiz question batches and user scores from a remote application server You learned how to use the AsyncTask class to handle background processing and keep your application responsive You also learned about many of the issues to be aware of when developing network enabled mobile applications Q What is the optimum batch size for downloads A This is a tricky question The short answer is not so much data that the user is tapping his or her foot waiting for the application to run but enough so that the user doesn t have to wait for downloads too often Ideally all downloading would take place behind the scenes while the user is doing something else such as answering the qu
136. Drawable resource repre senting the application In the Droid1 project you set the application icon to the Drawable resource as follows lt application android icon drawable icon gt Try It Yourself Although you will place just a single icon reference in the lt application gt tag attrib ute android icon you will need to create three different icons These will represent the three default icons for low pixel density screens ldpi high pixel density screens hdpi and medium pixel density screens mdpi The Android system will automati cally choose the appropriate graphic based upon the capabilities of the device the application is running on You will learn more about this topic in Hour 20 Developing for Different Devices For now you can just create a single graphic and then resize it for the three different resolutions To make your own custom application icons perform the following steps 1 Design a 48x48 pixel graphic with your favorite graphics program This is the icon for medium pixel density screens 2 Save the graphic in PNG format using the filename myicon png 3 Add the graphic file as a Drawable resource to your application in the res drawable mdpi directory Configuring Basic Application Settings 85 4 Repeat steps 1 3 but resize the graphic to 72x72 pixels and place it in the res drawable hdpi directory This is the icon for high pixel density screens 5 Repeat steps 1 3 but resize the
137. Eclipse allows seamless integration with many of the Android development tools If you re using Eclipse it s highly recommended that you install the in as it will make your life much easier The Plug in includes various wizards for creating and debugging Android projects To install the Android Plug in for Eclipse ADT you must launch Eclipse and install a custom software update The steps required depend on the version of Eclipse you use For complete instructions see the Android developer website http developer android com sdk eclipse adt html To install Android Plug in on Eclipse 3 5 Galileo follow these steps 1 Launch Eclipse 2 Select Help Install New Software 3 Select the Available Software tab 4 Click the Add button 5 Add the remote site https dl ssl google com android eclipse If this site fails try http dl ssl google com android eclipse 6 On the Available Software tab check the box next to Developer Tools box Also check the boxes for Android DDMS and Android Development Tools 7 Click the Next button and follow the wizard for installing the tools Accept the terms of the license agreement and click the Finish button 8 After the software update completes restart Eclipse After you install the Android SDK Eclipse plug in update your Eclipse preferences to point at the Android SDK you previously downloaded To do this launch Eclipse and Configuring Development Hardware for Device Debugg
138. Geocoding is the process of translating a description of a location into GPS coordi nates latitude longitude and sometimes altitude Geocoding enables you to enter a place name such as Eiffel Tower into Google Maps http maps google com and get the appropriate spot on the map Many geocoding services also have reverse geocoding abilities which can translate raw coordinates into some form of address usually a partial address Android devices may or may not have geocoding services available and geocoding obviously requires a back end service and the device must have network connectivi ty to be able to contact this back end service Different geocoding services support different types of descriptions but the following are some of the most common ones gt Names of towns states and countries gt Various forms of postal style addresses full and partial gt Postal codes gt Airport codes for example LAX LHR JFK gt Famous landmarks Of course most geocoding services also allow input of raw coordinates latitude and longitude as well Geocoding services are often localized Geocoded addresses are often ambiguous so a geocoding service may return multi ple records For example if you were to try to resolve the address Springfield you would likely get quite a few results because there is a town called Springfield in about 35 states in the United States and there are even more Springfields abroad You might also
139. IME support you must add these Apache libraries to your proj ect as JAR files Specifically you ll need to add the following JAR files to your project gt Mime4j http james apache org mime4j index html gt HttpMime 4 0 http hc apache org httpcomponents client httpmime index html gt Apache Commons IO http commons apache org io Don t know what multipart MIME is A great description is available on Wikipedia Dig you http en wikipedia org wiki MIME Multipart_messages Essentially multipart ow MIME is a way of encoding multiple pieces of data including binary data in a single text message Multipart MIME messages used with an HTML form corre spond to the content encoding type multipart form data Multipart MIME is not limited to HTTP For example email messages often use multipart MIME Try It Yourself v Adding a JAR File to an Android Project To add a JAR file to an Android project follow these steps 1 Download the JAR file s you want to include in your project 2 Create a directory called libs in your project This folder should be at the same level as the src and res folders 3 Copy the JAR file s to the libs directory 4 Under Android Project Properties select the Java Build Path menu option and navigate to the Libraries tab 5 Click the Add JARs button and choose the JAR files you want to add to the project Click OK 6 Refresh the project if necessary Code awa
140. ImageSwitcherFactory to gen erate a new ImageView control with the Drawable object supplied in the setImageDrawable parameter Animating ViewSwitcher To animate the transition between the child View controls of ViewSwitcher you use the setInAnimation and setOutAnimation methods For example to add fade in and fade out animations to the TextSwitcher control you could load and set the built in Android fade animations as follows Animation in AnimationUtils loadAnimation this android R anim fade_in Animation out AnimationUtils loadAnimation this android R anim fade_out TextSwitcher questionTextSwitcher TextSwitcher findViewById R id TextSwitcher_QuestionText questionTextSwitcher setInAnimation in questionTextSwitcher setOutAnimation out Now each time the setText method or setCurrentText method of TextSwitcher is called this fade animation will run You can now improve the question transition further by adding the same animations to the ImageSwitcher displaying the question images 207 208 HOUR 12 Adding Application Logic Wiring Up Game Logic The Been There Done That application has an open ended set of trivia questions Therefore you cannot save all the questions as resources but instead need to devel op a simple way to get new questions on the fly Also by storing the complete set of trivia questions in a remote location you streamline the application on the handset saving disk space
141. K 6 You can read the license agreement and download the latest version of the Java Standard Edition JDK at Sun s website http java sun com javase downloads For specific installation for your operating system see the documentation available with the installation pack age you choose Installing the Eclipse IDE Most developers use the popular Eclipse IDE for Android development this IDE is available for Windows Mac and Linux operating systems You can develop Android applications using either Eclipse 3 4 Ganymede or Eclipse 3 5 Galileo If this is your first time using Eclipse you ll probably want to choose the Eclipse IDE for Java EE Developers This version of the Eclipse IDE includes the Eclipse Java Development Tools JDT plug in and the optional Web Tools Platform WTP You can read the license agreement and download the Eclipse IDE for Java EE Developers at www eclipse org downloads The Eclipse package comes as a compressed zip file There is no installer You unzip the package into the desired folder and then follow the specific instructions in the following sections for your target operating system Notes on Windows Installations Once you ve installed the files in the appropriate location navigate to the Eclipse exe executable and create a shortcut on your desktop Edit the shortcut and modify the target field with any command line arguments you desire Notes on Mac OS X Installations If you are inst
142. KNAME Nickname String public static final String GAME_PREFERENCES EMAIL Email String public static final String GAME_PREFERENCES_ PASSWORD Password String public static final String GAME_PREFERENCES_DOB DOB Long public static final String GAME_PREFERENCES_ GENDER Gender Int 175 FIGURE 10 8 The Been There Done That set tings screen 176 HOUR 10 Building Forms to Collect User Input Saving Settings to SharedPreferences Now that you have defined the preference settings you can save any committed form field to the game preferences Within the QuizSettingsActivity class you begin by defining a SharedPreferences member variable SharedPreferences mGameSettings Within the onCreate method of the activity you initialize this member variable as follows mGameSettings getSharedPreferences GAME_PREFERENCES Context MODE_PRIVATE You pass in the name of your SharedPreferences the String called GAME_PREF ERENCES you created in the QuizActivity class The mode called MODE_PRIVATE is the default permission used for private application files Now anyplace you need to save a preference you simply open SharedPreferences Editor assign a specific preference setting and commit the change For example to save the Nickname EditText information you retrieve the text by using the EditText control s getText method final EditText nicknameText EditText findViewById R id EditText_N
143. Launching Google Street View and supplying a location gt Launching the built in Camera application in still or video mode gt Launching a ringtone picker v Recording a sound Here is an example of how to create a simple intent with a predefined action ACTION_VIEW to launch the web browser with a specific URL Uri address Uri parse http www perlgurl org Intent surf new Intent Intent ACTION_VIEW address startActivity surf This example shows an intent that has been created with an action and some data The action in this case is to view something The data is a uniform resource identi fier URI which identifies the location of the resource to view For this example the browser s activity then starts and comes into foreground caus ing the original calling activity to pause in the background When the user finishes with the browser and clicks the Back button the original activity resumes Working with Dialogs 53 Applications may also create their own intent types and allow other applications to call them allowing for tightly integrated application suites The Openintents org website keeps a list of intent actions at Did you www openintents org en intentstable This list includes those built into Android as ow well as those available from third party applications Working with Dialogs Handset screens are small and user interface real estate is valuable Sometimes you want to handle a sma
144. Lauren Darcey Shane Conder Sams Teach Yourself Android Application Development SAM 800 East 96th Street Indianapolis Indiana 46240 USA Sams Teach Yourself Android Application Development in 24 Hours Copyright 2010 Lauren Darcey and Shane Conder All rights reserved No part of this book shall be reproduced stored in a retrieval system or transmitted by any means electronic mechanical photocopying recording or otherwise without written permission from the publisher No patent liability is assumed with respect to the use of the information contained herein Although every precaution has been taken in the preparation of this book the publisher and author assume no responsibility for errors or omissions Nor is any liability assumed for damages resulting from the use of the information contained herein Visible Earth images owned by NASA http visibleearth nasa gov ISBN 13 978 0 321 67335 0 ISBN 10 0 321 67335 2 Library of Congress Cataloging in Publication Data Darcey Lauren 1977 Sams teach yourself Android application development in 24 hours Lauren Darcey Shane Conder p cm Sams teach yourself in 24 Hours Includes index ISBN 978 0 321 67335 0 pbk 1 Application software Development 2 Android Electronic resource 3 Mobile computing Conder Shane 1975 ll Title QA76 76 A65D26 2010 005 1 dc22 2010011663 Printed in the United States of America First Printing Ju
145. O TAKEN break case TAKE_AVATAR_GALLERY_ REQUEST if resultCode Activity RESULT_CANCELED Avatar gallery request mode was canceled else if resultCode Activity RESULT_OK TODO HANDLE IMAGE CHOSEN break Working with Image Media 225 Note that the user might launch an activity and then cancel it In this case the resultCode of the onActivityResult method is Activity RESULT_CANCELED However when the resultCode parameter is Activity RESULT_OK you should have a valid result to handle Because both cases result in a graphic you want to save as an application avatar you can create a helper method called saveAvatar This method can take a bitmap save it as a local file and use it within the Been There Done That applica tion The pseudo code for the saveAvatar method looks like this private void saveAvatar Bitmap avatar TODO Save the Bitmap as a local file called avatar jpg TODO Determine the Uri to the local avatar jpg file TODO Save the Uri path as a String preference TODO Update the ImageButton with the new image Working with the Camera There are many ways to incorporate camera hardware into your application You can build camera support directly into your application or you can integrate existing camera support functionality into your application by using the Intent mechanism For more fine tuned control over the handset camera hardware you can use the H android
146. Pair score score toString vars add new BasicNameValuePair nickname nickname vars add new BasicNameValuePair email email vars add new BasicNameValuePair password password p vars add new BasicNameValuePair gender gender toString vars add new BasicNameValuePair faveplace favePlaceName vars add new BasicNameValuePair dob birthdate toString String url TRIVIA_SERVER_ACCOUNT_EDIT URLEncodedUtils format vars null HttpGet request new HttpGet url ResponseHandler lt String gt responseHandler new BasicResponseHandler HttpClient client new DefaultHttpClient String responseBody client execute request responseHandler if responseBody null amp amp responseBody length gt Integer resultId Integer parseInt responseBody Editor editor mGameSettings edit editor putInt GAME_PREFERENCES_PLAYER_ID resultId editor commit succeeded true return succeeded Don t be overwhelmed by this code It is actually pretty straightforward You begin by creating a vector of name value pairs for each of the player settings saved in SharedPreferences that you want to communicate to the server If this is the first time these player settings are being communicated to the server a new record will be created The new record is basically an empty player record on the server with only one value the device s unique identifie
147. SDK comes with the android graphics package which includes a number of handy classes for drawing on the screen see Figure 21 4 Some features of the Android graphics package include bitmap graphics utilities and support for typefaces fonts paints gradients shapes and animation There are also helper classes such as the Matrix class that can help perform graphics operations EIS torn hile be dimensional graphic created with Android Using the OpenGL ES Graphics API For more advanced graphics Android uses the popular OpenGL ES graphics API 1 0 and it provides limited support for OpenGL ES 1 1 Applications can use Android s OpenGL ES support to draw animate light shade and texture graphical objects in three dimensions see Figure 21 5 356 FIGURE 21 5 An OpenGL ES graphic created with Android HOUR 21 Diving Deeper into Android BME 7 08 pm Android OpenGL ES Personalizing Android Devices Personalization of a device involves allowing the user to change the look and behavior of their user experience From the software side personalization involves configuring features such as the wallpaper ringtone and such Android allows a deep level of customization and personalization Alternate home screens themes graphics and sounds can be modified Android applications can provide many of these personalization features to users For instance a branded application might allow the users to set r
148. T What a mess Be fanera can causel A R it before aE a r F 16 too Tate Here s what you ll find on the authors website gt Information about Android SDK updates gt Market news and information related to Android and other mobile technologies gt Tips tricks and pitfalls of Android development gt Links to public reviews of this book gt Supplemental code examples Leveraging Online Android Resources 425 gt Informal discussions of more advanced Android development topics gt Links to other Android materials written by the authors including their more advanced Android book and technical articles available online Contacting the Authors l em f gmail com Send the authors feedback at androidwirelessdev We welcome your feedback If you have comments questions or concerns about the content of this book you can email us Lauren and Shane at androidwirelessdev gmail com see Figure C 3 We do our best to answer each and every query and often post commonly asked questions and their answers on the book website at http androidbook blogspot com FIGURE C 3 Send us feedback Leveraging Online Android Resources The Android developer community is friendly and helpful Here are a number of useful websites for Android developers and followers of the wireless industry in general gt Android Developer Website The Android SDK developer reference site and forums http dev
149. Text control called EditText_Nickname you use the getText method as follows EditText nicknameText EditText findViewById R id EditText_Nickname String strNicknameToSave nicknameText getText toString The getText method returns an Editable object but in this case you simply want its String value equivalent Using Common Form Controls 169 Committing EditText Input To handle EditText input to a form you need to determine when new text has been entered To do this you can listen for EditText key events and commit the text entered when certain keys are pressed For example to listen for the Enter key during input of the Nickname setting you would register View OnKeyListener by using the setOnKeyListener method of the EditText control as follows final EditText nicknameText EditText findViewById R id EditText_Nickname nicknameText setOnKeyListener new View OnKeyListener public boolean onKey View v int keyCode KeyEvent event if event getAction KeyEvent ACTION_ DOWN amp amp keyCode KeyEvent KEYCODE_ENTER String strNicknameToSave nicknameText getText toString TODO Save Nickname setting strNicknameToSave return true return false 3 Listening for EditText Keystrokes Eventually you will design a Password dialog Say that you want to match the text strings within two EditText password fields called EditText_Pwd1 and EditText_Pwd2 while the user is typing A
150. User Interaction with Android App Widgets available at http www developer com ws article php 3837531 Handling User Interaction with Android App Widgets htm Workshop 319 Q Can I have multiple instances of an App Widget A Having multiple instances doesn t make sense with the App Widget you implemented for the Been There Done That application However in certain instances it might make sense to allow the user to have multiple instances of an App Widget with different configurations One way to accomplish this is to allow the user to configure each App Widget instance using the configuration activity defined for the App Widget Then the application must keep track of the differences between the instances by keeping track of the user configura tion activity for each App Widget identifier We also cover this advanced topic in our article Handling User Interaction with Android App Widgets see the previous Q amp A for details Workshop Quiz 1 True or False App Widgets can reside only on the Home screen 2 Which of the following is an example of a View widget that cannot be used with an App Widget A Button B WebView C ProgressBar 3 True or False Although App Widgets are defined in pixels their size must cor respond directly to a certain number of cells 4 For what reason is a service used in an App Widget A To handle lengthy background operations B To handle drawing directly on the screen C T
151. Within the loop you watch for the START_TAG event When the tag name matches the lt score gt tag you know you have a piece of score data You then extract the data by using the getAttributeValue method For each score you find you add a new TableRow control to the appropriate TableLayout control in the appropriate tab Applying Finishing Touches to the Scores Screen After you have written the code to parse the two mock XML files and populate the two TableLayout controls in the TabHost control you need only make a few minor additions to QuizScoresActivity You should add a header TableRow to each TableLayout control with nicely styled column headers as well as handling for the case where no score data is available When you re done applying these finishing touches you save the class and run the application in the emulator or on the device When you navigate to the scores screen you see that both tabs are populated with data see Figure 9 6 FIGURE 9 6 8 19 PM wile The Been There Done That scores screen 158 HOUR 9 Developing the Help and Scores Screens Summary In this hour you added two new screens to the Been There Done That trivia appli cation As you implemented the help screen you learned how to display large amounts of data by using a scrolling TextView control You also learned how to access a file resource and change layout characteristics programmatically With the scores screen you learned a
152. You can then pass the bitmap into your helper method called saveAvatar Working with Bitmaps You now have two methods of retrieving a bitmap graphic to save as the applica tion avatar You can use the Bitmap class android graphics Bitmap to create manipulate and save graphics on the device The Bitmap class encapsulates various bitmap style graphics formats including PNG and JPG Do not confuse this with the bitmap file format image bmp You use the Bitmap class to create and manipulate PNG and JPG graphics on the Android handset Saving Bitmap Graphics You can use the compress method of the Bitmap class to save a bitmap in various formats For example to save the avatar bitmap to a private application JPG file you could use the following code String strAvatarFilename avatar jpg avatar compress CompressFormat JPEG 100 openFileOutput strAvatarFilename MODE_PRIVATE You can determine the URI address of a file by using the fromFile method of the Uri class For example to determine the URI for the avatar graphics file you just saved using the compress method you could use the following Uri imageUri Uri fromFile new File getFilesDir strAvatarFilename Working with Bitmaps After you have saved the avatar to a file and generated the appropriate URI you can update the ImageButton control contents with the new image Now if you run the application and choose an avatar via the camera or
153. a and a plus sign E on the Eclipse toolbar The first time you try to create an Android Project you might need to choose File New Project and then select the Android Android Project After you have done this once it appears in the Eclipse project types and you can use the method described in Step 1 2 Choose a project name In this case name the project Droid1 3 Choose a location for the project Because this is a new project select the Create New Project in Workspace radio button Check the Use Default Location check box If you prefer to store your project files in another location simply uncheck the Use Default Location check box and browse to the directory of your choice Familiarizing Yourself with Eclipse 4 Select a build target for your application For most applications you want to select the version of Android most appropriate for the devices used by your target audience and the needs of your application If you will be using the Google add ons for example Google Maps be sure to choose the Google APIs version for your target platform For this example the Android 2 1 API level 7 build target is sufficient 5 Specify an application name This name is what users will see In this case call the application Droid 1 6 Specify a package name following standard package namespace conventions for Java Because all code in this book falls under the com androidbook namespace use the pa
154. a remote application server to get live data To do this you need to learn about the networking features available on the Android platform as well as how to offload tasks from the main UI thread and execute them asynchronously 256 HOUR 15 Adding Network Support Two classes of the Been There Done That application need to download informa tion from an application gt QuizScoresActivity This class needs to download score information gt QuizGameActivity This class needs to download each batch of trivia ques tions To enable the Been There Done That application to handle live data you need to access an application server as well as add networking functionality to the client Android application The full implementation of the networking code provided in this hour is available on the book s website http www informit com title 9 780321673350 Working with an Application Server Network enabled applications often rely on an application server The application server provides centralized data storage a database and high performance process ing power Using a centralized server also allows the developer to develop a single server side with multiple client applications For example you could easily write iPhone BlackBerry and web versions of the Been There Done That application that use the same back end application server Scores and friends could then be shared across multiple client environments easily
155. a string array Adding New String Resources The settings screen relies on numerous new string resources You add the following text resources to the strings xml resource file gt Text for each setting s TextView label for example Nickname gt Text for each Button control for example Set Password gt Text to display in a TextView control when the password is set or not set gt Text to display in a TextView control when the Date of Birth field is not set gt Text to display in a TextView control when the two Password fields match or don t match gt Text for each Gender option in the Spinner control for example Male After you have added these strings save the strings xml resource file Adding New String Array Resources Spinner controls like ListView controls use data adapters You have your gender string resources defined but you still need to group them into some sort of dataset The simplest dataset is an array and the corresponding ArrayAdapter control To group the gender string resources Male Female Prefer Not To Say together into an array you create a new resource type called a String array To create a String array resource you must add a new resource file called res values arrays xml Within this file you create a new string array element called genders Within this string array element you add three Item elements one for each string resource 166 HOUR 10 Building Forms
156. able directory creating the directory if necessary splash1 png splash2 png splash3 png and splash4 png These graphics will be displayed in the TableLayout control in the center of the splash screen The code for this project is available on the book website http www informit com title 9 780321673350 Implementing the Splash Screen Layout 117 Then you can add three new strings to the res values strings xml resource file one for the top title Been There one for the bottom title Done That and one for some version information multiple lines Technically you can now remove the splash string because you will no longer be using it Next you create a new resource file called res values colors xml to contain the three color resources you need one for the title text color a golden yellow one for the version text color grayish white and one for the version text background color deep blue Because you will be setting the overall background color of the splash screen to Did you__ black you do not need to create a special resource Instead you just use the ow built in Android resource android color black Finally you need to create some dimension resources in a new resource file called res values dimens xml You create three new dimension values one to control the title font size 24pt one to control the version text font size Spt and one to allow for nice line spacing between the
157. ad the chapters of this book in order As you progress through the book you ll note that we do not spell out each and every step that must be taken for each and every feature you implement to follow along in building the core application example For example if three buttons must be implemented on a screen we walk you step by step through the implementation of the first button but leave the implementation of the other two buttons as an exercise for you In a later chapter on a different topic we might simply ask you to implement some buttons on another screen Where we tell you to navigate through menu options we separate options using com mas For example if we told you to open a new document we d say Select File New Document This page intentionally left blank HOUR 1 Getting Started with Android What You ll Learn in This Hour A brief history of the Android platform Familiarizing yourself with Eclipse Creating Android projects v v v Vv Running and debugging applications Android is the first complete open and free mobile platform Developers enjoy a compre hensive software development kit with ample tools for developing powerful feature rich applications The platform is open source relying on tried and true open standards devel opers will be familiar with And best of all there are no costly barriers to entry for devel opers no required fees A modest fee is required to publish on third party distribu
158. ae eae feature 416 cancellation 270 271 res 12 15 16 62 on automated testing with progress indicator res drawable 13 268 270 adding more tests resource directory qualifiers progress updates 379 380 334 335 269 270 creating test cases jee 12 ScoreDownloaderTask are values 16 class 267 creating test projects dismiss method 264 Draw 9 Patch tool 39 374 375 dismissDialog method 53 drawable resources explained 374 183 184 adding to Been There Done running automated tests dismissing That game 104 SASA dialogs 184 images build errors resolving 420 progress dialog 273 loading 67 classes creating 415 displaying scores 267 code comments 416 ShapeDrawable class 67 i code editing 416 417 background processing supported image formats ring 268 269 66 67 code formatting 418 cancellation 270 271 code organization 418 Droid 1 project friends scores 298 creating 10 11 developing Android progress indicator 268 270 creating debug and run con applications without 39 progress updates 269 270 figurations 18 19 imports organizing 415 416 ScoreDownloaderTask debugging with DDMS 21 22 installing 410 class 267 integrating with source editing project resources AndroidManifest xml file controlipackages Aal 13 15 log filters 420 How can we make this index more useful Email us at indexes samspublishing com 438 Eclipse IDE manifest file resource editor AndroidManifest xml
159. ail address and view friends scores Finally you learned about many of the third party social networking services you can consider integrating your application with Q How do I determine the best unique identifier to distinguish users A Despite a number of initiatives to implement single login services there is still not a great answer to this question Some candidates are unique username password pairings email addresses or phone numbers In the example in this hour we relied on the email address of the player as a unique identifier and we allowed the user to set up a password Many social network ing sites use a similar mechanism but this approach is not without prob lems for example email addresses change users may have more than one account and they have to keep track of yet another login and password com bination When you re integrating with a social networking website you need to use whatever authentication and credentials are required by the site s API Q What are some of the privacy concerns I should consider when developing social applications A When it comes to social applications you should always include information about how you ll use any information supplied by the user You re going to be safest when you follow these principles Don t access use or store any infor mation your application doesn t require and do assume that any and all information supplied by the user is private Now by this def
160. ality is not guaranteed so enabling network support gives your application a variety of opportunities to fail 258 waihi Oat HOUR 15 Adding Network Support The Android system addresses these issues in part through permissions but much of the burden of managing the impact of network features and performance falls upon the developer Here are some guidelines for developers leveraging network features within applications gt Use network services only when they are needed and cache data locally when ever possible gt Inform the user when collecting and using sensitive data as appropriate gt Allow the user to configure and disable features that might adversely affect his or her experience when using your application For example develop an air plane mode for your application to allow the user to enjoy your application without accessing a remote server gt Gracefully handle events such as no network coverage Your application is more valuable to the user if it is useful even without an Internet connection gt Consider including a privacy message as part of your application s terms of use Use this opportunity to inform the user about what data is collected from the user how it will and will not be used and where it is stored for example on a remote application server Most Android devices on the market at this time are Internet enabled phones and tablets but the Android platform is not limited to just
161. alization Some types of applications require complete internationalization Providing custom resources for each supported language and locale is a time intensive endeavor and Using Localization Utilities you should not do it unless you have a really good reason to do so because the size of the application grows as you include more resources This approach often necessi tates breaking the individual languages into separate APK files for publication resulting in more complex configuration management However this allows a devel oper to tailor an application for each specific marketplace to a fine degree Some of the pros of this strategy are the following gt The application is fully tailored and customized to individual audiences this strategy allows for tweaks to individual locales gt It builds user loyalty by providing users with the best most customized experi ence This is also a technique used by Google Some of the cons of this strategy are the following gt It is the most lengthy and complicated strategy to develop gt Each internationalized version of the application must be fully tested as if it were a completely different application which it may well be if you are forced to split it into different APK files due to application size Beware of over internationalizing an application The application package size will grow as you add language and locale specific resources There is no reason to head down t
162. alling Eclipse on a Mac OS X system make sure to review the README html file included with the Eclipse package This readme file covers how to Installing the Android SDK 411 pass command line arguments to Eclipse using the eclipse ini file and how to run more than one instance of Eclipse so that you can work with multiple project work spaces simultaneously If you don t want to use Eclipse you can find more information about configuring Did you__ your computer for Android development with other IDEs at the Android website ow http developer android com guide developing other ide html Installing the Android SDK You need to install the Android SDK to develop Android applications The Android SDK includes the Android JAR file Android application framework classes as well as Android documentation tools and sample code The Android SDK is available from the Android Developer website at http developer android com sdk index html You need to agree to the Android license agreement prior to installing the developer package Newer versions of the Android SDK have a helpful installer You simply download the compressed file unzip it into the desired folder and launch the setup The com pressed SDK files require about 25MB of hard drive space and uncompress to a size of approximately 40MB The Android tools and SDK versions are componentized This means that instead of installing one large package for development f
163. ame hello gt Hello lt string gt lt resources gt String resources have a number of formatting options Table 4 1 shows some simple examples of well formatted string values Strings that contain apostrophes or single straight quotes must be escaped or wrapped within double straight quotes TABLE 4 1 String Resource Formatting Examples String Resource Value Will Be Displayed As Hello World Hello World Hello World Hello World Mother s Maiden Name Mother s Maiden Name He said No He said No There are several ways to access a string resource programmatically The simplest way is to use the getString method String greeting getResources getString R string hello Working with Colors You can apply color resources to screen controls You tag color resources with the lt color gt tag and store them in the file res values colors xml This XML resource file is not created by default and must be created manually You can add a new XML file such as this one by choosing File New Android XML File and then fill out the resulting dialog with the type of file such as values This will automatically set the expected folder and type of file for the Android project Working with Simple Resource Values Here is an example of a color resource file lt xml version 7 0 encoding utf 8 gt lt resources gt lt color name background_color gt 006400 lt color
164. an be used to generate the current question ImageView and switch in the next ques tion s ImageView when the user clicks a Button control Similarly a TextSwitcher control has two child TextView controls with transitional animation applying to the text 199 FIGURE 12 2 Layout design for the Been There Done That game screen 200 HOUR 12 Adding Application Logic Figure 12 3 shows the updated layout design of the game screen which uses an ImageSwitcher control and a TextSwitcher control FIGURE 12 3 Revised layout design for the Been There RelativeLayout Done That game ImageSwitcher and TextSwitcher controls LinearLayout Vertical Orientation ImageSwitcher Question Specific Graphic TextSwitcher Question Specific Text Button Yes Button No Implementing the Game Screen Layout To implement the game screen you begin by adding new resources to the project Then you need to update the game xml layout resource to reflect the game screen design Adding New Project Resources For the game screen you need to add some new resources gt String resources for the text on the Button controls as well as the text to dis play when no questions are available Implementing the Game Screen Layout 201 gt Miscellaneous Dimension and Color resources needed to design the game screen controls gt Two XML resources with mock question batches You should now be comfortable creating any Str
165. an intuitive user interface and you have to get that app out to users quickly before someone else does A killer app must have the right mix of these ingredients but a poor implementation of an excellent idea isn t going to become a killer app so it s important to test an application thoroughly before you publish it In this hour you learn how to test mobile applications in a variety of ways Testing Best Practices Mobile users expect a lot from today s mobile applications They expect the applications they install to be stable responsive and secure Stable means that the application works and doesn t crash or mess up the user s phone Responsive means the phone always responds to key presses and long operations use progress bar indicators Secure means that the application doesn t abuse the trust of the user either intentionally or unintention ally Users expect an application to have a reasonably straightforward user interface and they expect the application to work 24 7 especially when it comes to networked applica tions with a server side It might seem like users expect a lot for an application that might be priced at 0 99 but really do any of these expectations seem unreasonable We don t think so However they do impose significant responsibilities on a developer in terms of testing and quality control 368 Dw HOUR 22 Testing Android Applications Whether you re a team of one or one hundred every mob
166. and com This list is not complete and we don t specifically endorse any one market over another but it is important to note that there are a number of alternative distribu tion mechanisms available to developers Application requirements vary by store In addition to these many manufacturers and wireless operators have their own stores especially for devices that don t include the Google experience that is devices that don t include Google apps such as the Android Market Third party application stores are free to enforce whatever rules they want on the applications they accept so carefully read the fine print at each site A particular site may enforce content guidelines require additional technical support and enforce digital signing requirements Only you and your team can determine which sites are suitable for your specific needs Anyone can develop a new Android application store and market applications on his or her own terms That s one of the benefits of an open and free platform Q amp A 405 Summary In this final hour you learned how to publish an Android application for the world to see and use You now know there are several different publishing avenues includ ing self publishing from your website as well as a variety of third party application stores that can help you sell your work usually for a cut of the profit You also learned how to set up a developer account with the Android Market one of
167. anguages such as C may be added in the future Although applications must be Java C and C can be used for certain routines that need higher performance by using the Android NDK For more information about using the Android NDK see http developer android com sdk ndk 24 HOUR 1 Getting Started with Android Q Why would want to create AVDs for Android 1 1 or any older firmware when newer versions of the Android SDK are available A Although handset firmware may be updated over the air not every Android device will support every future firmware version Check the firmware avail able on each of your target handsets carefully before choosing which version your application will support and be tested on Q The Android resource editors can be cumbersome for entering large amounts of data such as many string resources Is there any way around this A Android project files such as the Android manifest layout files and resource values for example res values strings xml are stored in specially for matted XML files You can edit these files manually by clicking on the XML tab of the resource editor We will talk more about the XML formats in Hour 4 Workshop Quiz 1 Who are the members of the Open Handset Alliance A Handset manufacturers B Wireless operators and carriers C Mobile software developers D All of the above 2 True or False You can simply launch the Android emulator to use default set tings right af
168. aphics 355 android media 353 android provider 360 android service wallpaper 357 android speech Recognizer Intent 353 android speech tts 352 installing 390 391 java io 358 naming 82 packaging applications 387 390 parse method 248 parsing declaring string literals for question parsing 209 question batches 271 272 dismissing progress dialog 273 handling background processing 273 starting progress dialog 272 SAX parser 74 XML files 156 157 XMLPullParser 74 passing information with intents 51 52 password dialog adding to QuizSettingsActivity class 190 193 designing 188 189 implementing layout 190 launching 193 performance of animation 124 performance testing 370 lt permission gt element 347 permissions 347 BATTERY_STATS 363 including in Android manifest file 92 managing 88 91 network permissions 260 phone state permissions 278 Permissions tab manifest file 14 79 80 personalization explained 356 ringtones 356 wallpaper 356 357 phone status information accessing retrieving telephony information call state information 279 CDMA GSM information 279 280 network roaming information 280 network type information 279 SIM information 280 voice mail information 280 setting phone state permissions 278 PlayActivity class 44 player relationships enhancing 299 300 pleaseWaitDialog control 264 plug ins See ADT Android Develop
169. ard http proguard sourceforge net do support Android The Android Market application publication screen also includes a mysterious undocumented check box for copy protection when publishing your application Workshop Quiz 1 True or False You don t need an account to sell on the Android Market 2 Which of the following statements are true A The Android Market allows for paid and free applications B The Android Market allows developers to sell applications only in the United States C The Android Market is the only Android application store available D The Android Market imposes a 30 transaction fee on applications sold E All of the above 3 True or False You can sell Android applications from your own website 4 Before submitting an application to the Android Market which of the follow ing must you do A Certify your application through an approved expensive certification pro gram B Provide a notarized Statement of Testing Completeness proving you ve test ed every single aspect of the application in all scenarios C Sign your application package with a well known certificate authority approved for use with the Android Market D Record a video of your application in action Workshop 407 E Provide a Word document with thorough documentation of application flows and a complete user manual F Get certified carrier and operator approval from each and every carrier you plan on launching on b
170. ardware are not fully functional gt Phone calls cannot be placed or received but are simulated SMS messages are also simulated and do not use a real network gt No USB or Bluetooth support is available Using Android emulator is not a substitute for testing on a true target handset or device 35 36 HOUR 2 Mastering the Android Development Tools Providing Input to the Emulator As a developer you can provide input to the emulator in a number of ways gt Use your computer mouse to click scroll and drag items for example side volume controls onscreen as well as on the emulator skin Use your computer keyboard to input text into controls Use your mouse to simulate individual finger presses on the soft keyboard or physical emulator keyboard Use a number of emulator keyboard commands to control specific emulator states Vv Try It Yourself Try out some of the methods of interacting with the emulator 1 In Eclipse launch the Droid1 application you created in Hour 1 Getting Started with Android While your application is running press the control F11 and control F12 keys to toggle the emulator orientation Note how your application redraws the simple screen in portrait and landscape modes Press Alt Enter to enter full screen mode with the emulator Then press Alt Enter again to return to normal mode Many useful commands are available For an exhaustive list see the official emula t
171. are supported for color resources A 12 bit color B 24 bit color C 64 bit color 2 True or False You can include files of any format as a resource 3 Which graphics formats are supported and encouraged on Android A Joint Photographic Experts Group JPG B Portable Network Graphics PNG C Graphics Interchange Format GIF D Nine Patch Stretchable Images 9 PNG 4 True or False Resource filenames can be uppercase 5 True or False Naming resources is arbitrary Answers 1 A and B Both 12 bit and 24 bit color are supported 2 True Simply include a file as a raw resource 3 Band D Although all four formats are supported they are not all encour aged PNG graphics including Nine Patch Stretchable graphics are highly encouraged for Android development because they are lossless and efficient JPG files are acceptable but lossy and GIF file use is outright discouraged 4 False Resource filenames may contain letters numbers and underscores and must be lowercase 5 False The resource names dictate the variable names used to reference the resources programmatically 76 HOUR 4 Managing Application Resources Exercises 1 Add a new color resource with a value of 00ff00 to your Droid1 project Within the layout file change the textColor attribute of the TextView con trol to the color resource you just created Rerun the application and view the result 2 Add a new dimension resource with a value of 22pt
172. aries graphics libraries 355 linking 82 life cycles of activity dialogs 182 183 light sensor 362 limited internationalization 328 LinearLayout control 115 132 linking secondary libraries 82 Linux Android SDK installation 412 device debugging configuration 414 listen method 279 How can we make this index more useful Email us at indexes samspublishing com 444 listening listening for EditText keystrokes 169 170 for ListView events 135 136 for screen orientation changes 338 344 for selection events 174 ListView control 129 130 custom dividers 136 custom selectors 137 filling 134 135 listening for ListView events 135 136 live folders 361 loading images 67 scores screen 158 loadQuestionBatch method 273 locales Android Market support for 326 327 Android SDK support for 322 323 changing 324 choosing target locales 331 currency 330 date time formatting 330 defined 321 determining 329 330 resources specifying default resources 325 language specific resources 325 region specific resources 326 location testing enabling 241 243 Location Based Services LBS 352 LocationManager class 244 Log class 54 log filters 420 LogCat 35 logic See game logic logs filtering 35 log methods 54 logging application information 374 viewing log information 35 low memory conditions 55 Mac OS X Android SDK installation 412 device deb
173. as a string resource and create resource files for each locale you want to support We will talk more about localizing resources later in this book Q If permissions are not being enforced why should I include them in the Android manifest file A While your application might function even if you don t declare certain per missions this is dangerous behavior Firmware upgrades can result in the Android system enforcing these permissions at a future date causing your application to stop functioning properly Q added a new Activity class to my project and my application keeps crashing What did I do wrong A Chances are you forgot to register the activity in the Android manifest file If you don t register the activity by using an lt activity gt tag your application may crash upon launch Q IfI can use the Eclipse resource editor to edit the Android manifest file why do I need to know about the raw XML A When making straightforward configuration changes to the manifest file using the resource editor is the most straightforward method However when bulk changes must be made editing the XML directly can be much faster Q Why do need read permission to shared resources such as contacts A To protect the privacy of the user applications must register permission to read sensitive data While applications cannot do any direct harm to the Android system with just read access the information extracted from contacts or
174. at similar features the scores screen The requirements for this screen include showing several different scores to the user There are two types of scores the all time high scores and the user s friends scores You want to show both on the same screen Each screen shown will include the user s name score and overall ranking There are a number of ways you could implement the scores screen For example you could use a TextView control or ListView control to display the score informa tion However you are working with a small screen and you don t want to over whelm the user with too much information Because you have two different sets of data to display two tabs would be ideal for this screen Figure 9 4 shows a rough design of the scores screen FIGURE 9 4 Rough design for the Been There Done That scores screen Game Score Sample Tab Name Score Rank 12345 12344 12343 150 HOUR 9 Developing the Help and Scores Screens Determining Scores Screen Layout Requirements Now that you know how you want your scores screen to look you need to translate your rough design into the appropriate layout design In this case you need to update the res layout scores xml layout file that is used by the QuizScoresActivity class In the case of the scores layout you can again take advantage of the RelativeLayout control to add a familiar title bar to the top of the scores screen In this case the header will be followe
175. ate Private App Files and App Files and Databases Databases Android Platform Security Enforcement Try It Yourself vyv To give your application permission to access the built in camera use the following steps 1 Open the Droid1 project in Eclipse 2 Open the Android manifest file and click the Permissions tab of the resource editor 3 Click the Add button and choose Uses Permission The Name attribute for the permission is shown in the right side of the screen as a drop down list 4 Choose android permission CAMERA from the drop down list 5 Save the manifest file Switch to the AndroidManifest xml tab to see what the new XML looks like You have now registered the camera permission Your application will be able to access the camera without security exceptions A 90 HOUR 5 Configuring the Android Manifest File During the application installation process the user is shown exactly what permis sions the application uses The user must agree to install the application after reviewing these permissions Table 5 2 lists some of the most common permissions used by Android applications TABLE 5 2 Common Permissions Used by Android Applications Permission Category Useful Permissions Location based services android permission ACCESS COARSE_LOCATION android permission ACCESS_FINE_LOCATION Accessing contact database android permission READ CONTACTS android permission WRITE_CONTACTS Accessing
176. ate class MyImageSwitcherFactory implements ViewSwitcher ViewFactory public View makeView ImageView imageView new ImageView QuizGameActivity this imageView setScaleType ImageView ScaleType FIT_CENTER imageView setLayoutParams new ImageSwitcher LayoutParams LayoutParams FILL_PARENT LayoutParams FILL_PARENT return imageView Note that the source or contents of the view have not been configured in the makeView method Instead you can consider this a template that the ViewSwitcher control will use to display each child view When you create a ViewSwitcher control you can configure its ViewFactory using the setFactory method For example to set ViewFactory of the ImageSwitcher control you created for MyImageSwitcherFactory you do the following Working with ViewSwitcher Controls 205 ImageSwitcher questionImageSwitcher ImageSwitcher findViewById R id ImageSwitcher_QuestionImage questionImageSwitcher setFactory new MyImageSwitcherFactory Similarly you must create a ViewFactory to generate the TextView controls for each question on the game screen Here is an implementation of a ViewFactory called MyTextSwitcherFactory that does just that private class MyTextSwitcherFactory implements ViewSwitcher ViewFactory public View makeView TextView textView new TextView QuizGameActivity this textView setGravity Gravity CENTER Resources res getResources float dimension res getDimension R di
177. ateFormat to generate date and time strings in the current locale or you can customize date and time information as needed for your application You can use the TimeUtils class android util TimeUtils to determine the time zone of a specified country by name Handling Currencies Much like dates and times currencies and how they are formatted differ by locale You can use the standard java Currency class java util Currency to encapsu late currency information You can use the NumberFormat class java text NumberFormat to format and parse numbers based on locale informa tion Summary In this hour you reviewed basic internationalization principles such as externalizing project resources and knowing your target markets You learned how the Android platform handles different countries languages and locales Finally you learned how to organize Android application resources for a variety of different countries and regions for maximum profit using a number of different internationalization strategies Q amp A 331 Q Which languages and locales should target in my Android applications A The answer to this question depends on a variety of factors and is something of a numbers game The short answer is this the fewest you can get away with The number of mobile users who use a specific language should not be the only factor in deciding which languages to support For example there are many more Spanish and Chinese speak
178. ated tests can be performed on any Android device that can be connected for debugging C and D Unfortunately the JUnit framework alone can t physically move handsets around the world In addition it can t simulate nuances to specific carriers around the world However emulator options can be used to mimic certain network performance characteristics but not the specifics of a different networking environment Exercises 1 2 Develop a high level test plan for the Been There Done That application Write a test case for validating that a user s avatar uploads correctly Review the various agreements you have encountered in beginning to develop Android applications such as the Android SDK License Agreement and Google Maps API Terms and Conditions Identify any test cases that might be required for compliance with these agreements HOUR 23 Getting Ready to Publish What You l Learn in This Hour gt Preparing for application publication gt Testing and verifying a release build gt Packaging and signing your application for release An application may be functionally complete but you need to take one final step before you can publish You must package the application so that it can be deployed to users In this hour you will learn how to prepare and package an application for release on the most popular Android publishing program the Android Market Understanding the Release Process Preparing and packagin
179. ation can be tested and improved resulting in a higher quality product that users will appreciate You learned many best practices for testing mobile applications including the importance of creating a solid complete testing plan You learned about some of the ways you can acquire handsets for testing purposes You also learned how to create automated tests using the Android JUnit framework Finally you learned about some other specialized testing concerns that should be part of any good product test plan Q Are there any certification programs for Android applications A There are currently no certification programs for Android applications However providers operators and certain mobile marketplaces may impose their own application quality standards as they see fit Q Where can I find out more about creating automated test suites with JUnit A Visit the JUnit organization website at www junit org or find one of the many books on JUnit Workshop 381 Workshop Quiz 1 True or False Developers can create automated tests to exercise Android appli cations programmatically 2 Which of the following should be considered an application defect or bug An application takes a long time to start up An application crashes when there is an incoming call German text is too long to display onscreen and overflows Buttons are too small or close together to push with a finger An application enters an infinite loop when certain c
180. avior is the same regardless of the locale However the data must be local ized This is one of the key reasons resource files exist to externalize application data The most common type of application data that requires localization is the strings of text used by the application For example a string of data might represent a user s name but the text label for that value on an application screen would need to be shown in the proper language for example Name Nom Nombre Development platforms that support internationalization typically allow for string tables which can be swapped around so that the same application can target differ ent languages The Android platform is no exception Do not hard code string information into an application that is the Java source file unless absolutely necessary Doing so hinders internationalization efforts How Android Localization Works Compared to other mobile platforms the Android SDK provides reasonably exten sive support for internationalization However this is a fairly complex topic with lots of caveats and the Android documentation in this area is virtually nonexistent Android localization considerations fall into three main categories gt The languages and locales supported by the Android platform an extensive list the superset of all available languages gt The languages and locales supported by a specific Android handset a list that varies a subset of
181. b but they generally apply only in very specific cases such as when you want to apply a theme other than the default to your application There are also settings for handling how the application interacts with the Android operating system For most applications the default settings are acceptable You will be spending a lot of time on the Application tab in the Application Nodes box where you can register application components most commonly each time you register a new activity 86 HOUR 5 Configuring the Android Manifest File Defining Activities Recall that Android applications comprise a number of different activities Every activity must be registered within the Android manifest file before it can be used You need to update the manifest file each time you add a new activity to an application Each activity represents a specific task to be completed often with its own screen Activities are launched in different ways using the Intent mechanism Each activi ty can have its own label name and icon but uses the application s generic label and icon by default Registering Activities You can register each new activity in the Application Nodes section of the Application tab Each new activity has its own lt activity gt tag in the resulting XML For example the following XML excerpt defines an activity class called DroidActivity lt activity android name DroidActivity gt This activity must be defined as a cla
182. back reasonably quickly so that the main thread is not blocked If the main UI thread is blocked for too long the Android system will shut down the activity due to a lack of response This is especially important to respond quickly during the onPause callback when a higher priority task for example an incoming phone call is entering the foreground Figure 3 2 shows the order in which activity callbacks are called Request Activity Start onCreate onRestart Activity ect onResume Activity Foreground anit Background Activity Activity aD sor Ean ity Li Foreground Brought to g Activity Killed Foreground For Memory Activity Sent To Background onStop onDestroy Saving Activity State An activity can have private preferences much like shared application preferences You can access these preferences by using the getPreferences method of the Working with Intents 51 activity This mechanism is useful for saving state information For example PlayActivity for your game might use these preferences to keep track of the cur rent level and score player health statistics and game state Shutting Down Activities To shut down an activity you make a call to the finish method There are sever al different versions of this method to use depending whether the activity is shut ting itself down or shutting down another activity Within your ga
183. be defined within the activity in which it will be used A Dialog window may be launched once or used repeatedly Understanding how an Working with Activity Dialogs 183 activity manages the Dialog window life cycle is important to implementing a Dialog window correctly Let s look at the key methods that an activity must use to manage a Dialog window gt The showDialog method is used to display a Dialog window gt The dismissDialog method is used to stop showing a Dialog window The Dialog window is kept around in the activity s Dialog window pool If the Dialog window is shown again using showDialog the cached version is displayed once more gt The removeDialog method is used to remove a Dialog window from the Activity object s Dialog window pool The Dialog window will no longer be kept around for future use If you call showDialog again the Dialog win dow must be re created Defining a Dialog A dialog used by an activity must be defined in advance Each dialog has a special Dialog identifier an integer When the showDialog method is called you pass in this Dialog identifier as a parameter At that point the onCreateDialog method is called and must return a dialog of the appropriate type You must override the onCreateDialog method of an activity and return the appropriate dialog for a given identifier If an activity has multiple Dialog windows the onCreateDialog method can use a switch statement
184. benefit it s with mobile develop ment Wireless application development with its ridiculously expensive compilers and preferential developer programs has been notoriously expensive to break into compared to desktop development Here Android breaks the proprietary mold Unlike with other mobile platforms there are virtually no costs to developing Android applications The Android SDK and tools are freely available on the Android developer website http developer android com The freely available Eclipse program has become the most popular integrated development environment IDE for Android application development there is also a powerful plug in available on the Android developer site for facilitating Android development So we ve covered cheap now let s talk about why Android development is easy Because Android applications are written in Java developers will be familiar with many of the packages provided as part of the Android SDK such as java net Developers will be pleased to find that the learning curve for Android is quite rea sonable So let s get started Familiarizing Yourself with Eclipse Let s begin by writing a simple Android Hello World application that displays a line of text to the user As you do so you will also be taking a tour through the Eclipse environment Specifically you will learn about the features offered by the Android Development Tools ADT plug in for Eclipse The ADT plug in provid
185. bout the TabHost control as well as how to parse XML to display some mock score data Q amp A Q Why do need to name certain controls within the TabHost control with spe cific Android id attributes A Occasionally you will find situations in which you need to name layout con trols with specific names in order for the controls to work properly The more complex a control the more likely it requires a bit of glue or magic for the Android system to load the right templates and resources to display the control in a familiar way Usually these kinds of naming requirements are documented in the Android SDK Q There is a bit of a delay when loading the scores screen Why A There are a number of reasons this screen appears less responsive than other screens First you are parsing XML which can be a costly operation Second you create a large number of View controls to display the score data You must always be careful to offload intense processing from the main UI thread to make the application more responsive and avoid unnecessary shutdown by the Android system You could easily add a worker thread to handle the XML and you might also consider other more efficient controls for displaying the score data Finally with Eclipse when the debugger is attached performance of an application greatly degrades Workshop 159 Workshop Quiz 1 True or False A TextView control can display a large amount of text 2 What cla
186. bution is perhaps the easiest method of application distribution it may also be the most difficult in terms of marketing and protect your application Exploring Other Android Publishing Options and making money The only requirement for self distribution is to have a place to host the application package file The downside of self distribution is that the end user must configure his or her device to allow packages from unknown sources This setting is found under the Application Settings section of the device Settings application as shown in Figure 24 5 Quick launch eyboard shortcuts to launch applications Manage applications Manage and remove Installed applications Running services and control currently running services Development Set options for application development After that the user must enter the URL of the application package into the web browser on the handset and download the file or click a link to it Once the file is downloaded the standard Android installation process occurs during which the user needs to confirm the permissions and optionally confirm an update or replace ment of an existing application if a version is already installed Not all devices include the option for enabling installation from unknown sources For instance the ARCHOS 5 Internet Tablet does not include this option but luck ily automatically has this functionality turned on so users can install applications from an
187. button on the emulator over the area where you want to add the App Widget When the pop up menu appears choose Add to Home Screen Widgets Select the App Widget you just created or any other App Widget from the list and add it to your Home screen At this point the App Widget looks as shown in Figure 18 2 Handling App Widget User Events BME 3 16 pm Handling App Widget User Events As it stands the App Widget works but isn t terribly interactive You don t want it to just display information to the user you want it to also bring the user back to the application Another area where the App Widget might be improved is to make it handle slow avatar image downloads gracefully App Widgets are displayed through RemoteViews objects and not within the applica tion where they are created Instead they are displayed within an App Widget host This affects the handling of user input Recall that the list of views that an App Widget supports did not include any user input fields Basically the only event that an App Widget supports is a click event You may have seen a number of App Widgets such as the Facebook App Widget present what look like EditText fields However if you click on them to enter text you ll notice that in all cases a different Ul comes up to actually take the entry This method is an excellent way to provide advanced controls within the limita tions of the App Widget framework Becau
188. by using an iterator Iterator lt Address gt locations geocodeResults iterator while locations hasNext Address loc locations next double lat loc getLatitude double lon loc getLongitude TODO Do something with these coordinates Each Address object returned contains information about the location You can use the getLatitude and getLongitude methods of the Address class to access the location s coordinates You can also use the getFromLocationName method to limit the returned address results to a certain range Reverse Geocoding Translating Coordinates into Addresses You can use the Geocoder class s getFromLocation method to translate raw lati tude and longitude coordinates into address information Again you pass in the coordinates and the number of results to be returned 248 HOUR 14 Adding Support for Location Based Services Working with Maps Most map features of Android are provided with the special Google API add ons For example you can use the MapView control in your layout files to tightly integrate Google Maps features into applications You can also integrate with existing Maps applications available on the handset by way of the intent mechanism Launching a Map Application by Using an Intent Location applications such as the Maps application handle the ACTION_VIEW intent when supplied with a URI with geographic coordinates This URI has a special format When you have d
189. ces i18n html AlternateResources Handling Different Screen Orientations Android applications can run in landscape or portrait mode depending on how the user tilts the handset screen Besides internationalization one of the most common situations in which applications might want to customize resources is to handle screen orientation changes Adding a Custom Layout for Landscape Mode Thus far you have been developing and testing the Been There Done That applica tion in portrait mode Launch it now and change to landscape mode before launch ing the application Review each screen You ll note that some screens display fine they have flexible layouts that work well in either landscape or portrait mode and some screens such as the game screen see Figure 20 1 could use some work 336 FIGURE 20 1 The game screen in land scape mode default layout used Have you ever b en on an African safari Modifying how a screen displays based on the orientation of the device is as simple as adding a new set of layout resource files To do this you need to do the following gt Use all currently defined layout resources as the defaults gt Design a new version of each layout that also looks nice in landscape mode gt Add these new landscape specific layouts to the res layout land directory Let s give this a shot by providing two different versions of the game screen in the Been There Done That application one
190. cific tools tools folder 27 transformations 230 translating addresses coordinates 247 trivia game See Been There Done That application troubleshooting firmware upgrades 343 internationalization 331 TTS text to speech 352 tweened animation 119 Twitter support 301 457 uploading U UiThreadTest annotation 378 UI threads 50 Update Threads button 30 updateAppWidget method 311 314 updateDate method 186 updating game screen layout 202 203 help screen layout 146 ImageSwitcher control 207 scores screen layout 152 154 settings screen layout 166 167 SharedPreferences to include game state settings 208 209 splash screen layout 117 119 TextSwitcher control 205 upgrades testing 370 upgrading Android SDK 413 Upload Application button 397 uploading applications to Android Market 397 400 avatars 288 player scores 285 to servers determining data to send 277 278 explained 281 with HTTP GET method 282 285 with HTTP POST method 286 288 How can we make this index more useful Email us at indexes samspublishing com 458 UrlEncodedFormEntity class UrlEncodedFormEntity class 298 usability testing 370 USB debugging enabling 413 414 user gestures handling 351 352 user interfaces custom views 350 input methods 350 speech recognition 353 styles 349 350 themes 349 350 TTS text to speech 352 user gestures handling 351
191. ckage name com androidbook droid1 7 Check the Create Activity check box This will instruct the wizard to create a default launch Activity class for the application Call your activity DroidActivity What Is an Activity An activity is a core component of the Android platform Each activity represents a task the application can do often tied to a corresponding screen in the applica tion user interface The Droid 1 application has a single activity called DroidActivity which has a single responsibility to display a String to the user We will talk more about activities in Hour 3 Building Android Applications Your project settings will look as shown in Figure 1 2 8 Confirm that the Min SDK Version field is correct This field will be set to the API level of the build target by default Android 2 1 is API level 7 If you want to support older versions of the Android SDK you need to change this field However in this case we can leave it as its default value 9 Click the Next button 10 The Android project wizard allows you to create a test project in conjunction with your Android application For this example a test project is unnecessary However you can always add a test project later by clicking the Android Test Project creator icon which is to the right of the Android project wizard icon with the letter a letter J and letter u aap on the Eclipse toolbar Test projects are discussed in detail in Ho
192. content exists You can use the managedQuery method to retrieve data from a content provider and then iterate through the query results by using a cursor just as you would any database query result Exploring Some Commonly Used Content Providers The content providers included with Android can be found in the android provider package Here are some of the most useful content providers gt MediaStore Used to access media audio video and still images on the phone and on external storage devices gt CallLog Used to access information about dialed received and missed phone calls gt Browser Used to access the user s browsing history and bookmarked websites gt Contacts Used to access the user s contacts database gt UserDictionary A dictionary of user defined words for use with predictive text input Managing and Sharing Data 361 You can bind data from a database or content provider cursor directly to user Did you__ interface View controls such as ListView To do so use a data Adapter control ow such as ArrayAdapter or CursorAdapter and a View control derived from AdapterView such as a ListView or Spinner control Acting as a Content Provider An application can expose internal data to other applications by becoming a con tent provider To share information with other applications an application must implement a content provider interface and register as a content provider within the Android
193. control Configure the Button control with the id attribute Button_Password and the text attribute set to the Password button text string resource Configure the TextView control to display the Password setting state string Password not set for now 8 At the same level as the Password setting region add a region for the Date of Birth setting Start by adding another TextView control to display the Date of Birth label text Next add another horizontal LinearLayout control with two controls a Button control and a TextView control Configure the Button con trol with the id attribute Button_DOB and the text attribute set to the Date of Birth button text string resource Configure the TextView control to display the Date of Birth setting state string Date not set for now 9 Add one last settings region for the Gender drop down by adding a TextView control to display the Gender label text Then add a Spinner control and set its id attribute to Spinner_Gender 10 Before saving adjust any text sizes fonts colors height or width settings until the screen draws as desired At this point save the settings xml layout file Using Common Form Controls Now that the settings xml layout file is complete you need to update the QuizSettingsActivity class to populate the controls and allow editing and saving of form data This section shows you how to save and restore data to the form 168 FIGURE 10 3 An EditText control for text
194. cores available if bFoundScores false publishProgress The publishProgress method can be called anytime within the doInBackground method to cause the onProgressUpdate callback method to be called This allows the background process to communicate with the UI thread Handling Progress Updates You can update the UI thread with background progress information by overriding the onProgressUpdate method Here you grab the new score just parsed from the method parameters and insert a new row in the score TableLayout control 0verride protected void onProgressUpdate String values if values length 3 270 HOUR 15 Adding Network Support String scoreValue values Q String scoreRank values 1 String scoreUserName values 2 insertScoreRow table scoreValue scoreRank scoreUserName else final TableRow newRow new TableRow QuizScoresActivity this TextView noResults new TextView QuizScoresActivity this noResults setText getResources getString R string no_scores newRow addView noResults table addView newRow The insertScoreRow method simply creates a new TableRow control and adds it to the TableLayout control The array of values must be passed in the same order each time This is because of how the AsyncTask Java template works Clearing the Progress Indicator Next you implement the onPostExecute method which runs on the UI thread after background processing com
195. createFromResource method ArrayAdapter lt gt adapter ArrayAdapter createFromResource this R array genders android R layout simple_spinner_item adapter setDropDownViewResource android R layout simple_spinner_dropdown_item Finally you call the setAdapter method of the Spinner control to bind the data to the control spinner setAdapter adapter Handling Spinner Selections After the Spinner control has been filled with data you can control which item is selected by using the setSelection method For example you know that the option for female gender is stored in the string array at index 2 because you use a 174 HOUR 10 Building Forms to Collect User Input 0 based string array Because you conveniently decide to map the indexes directly to the gender values you can set the Spinner control to the Female option by using the setSelection method as follows spinner setSelection 2 The Spinner class also includes a number of methods for retrieving the current item selected Listening for Selection Events You want to save the Spinner control option chosen as soon as the user selects one To do this you use the setOnItemSelectedListener method of the Spinner con trol to listen for selection events Specifically you need to implement the onItemSelected method of AdapterView OnItemSelectedListener like this spinner setOnItemSelectedListener new AdapterView OnItemSelectedListener Ov
196. creen are used to drive the ImageSwitcher and TextSwitcher controls Each time the user clicks a Button control any score changes are logged and the ViewSwitcher controls are updated to display the next question In this way the Button controls drive the activity forward and the user progresses through the trivia quiz questions There is little difference between the handling of the Yes and No Button controls Let s take a closer look at the OnClickListener OnClick method of the Yes Button control Button yesButton Button findViewById R id Button_Yes yesButton setOnClickListener new View OnClickListener public void onClick View v handleAnswerAndShowNextQuestion true 3 The View onClickListener method for the corresponding No Button is almost identical to the Yes Button control handler shown here The only difference is that you pass a false value into the handleAnswerAndShowNextQuestion method This is a custom method you will implement to log the score change and handle any ViewSwitcher logic Now let s look in more detail at the handleAnswerAndShowNextQuestion method which takes one parameter boolean bAnswer First examine the following pseudo code showing what this Button handler will do private void handleAnswerAndShowNextQuestion boolean bAnswer Load game settings like score and current question Update score if answer is yes Load the next question handling if there are no more q
197. cribed here For example you could create a SQL database driven applica tion server using MySQL and PHP instead or you could use a number of other technologies Informing the User of Network Activity In this hour we re most interested in how to query the application server and retrieve the XML returned from a query Networking support does not necessitate any specific user interface or layout updates to the Been There Done That applica tion However any time the user is required to wait for an operation that takes time for example for XML data to be downloaded from a server and parsed it is important to inform the user that something is happening using a visual mecha nism such as an indeterminate ProgressBar control as shown in Figure 15 1 Otherwise the user might abandon the application due to lack of response FIGURE 15 1 Using an inde terminate progress bar to inform the user about a lengthy operation Trivia Quiz Downloading trivia questions Developing Network Applications Developers who enable network support in applications need to be aware of a num ber of issues These issues are very similar to those faced when enabling Location Based Services LBS features in an application User privacy concerns device per formance degradation and unwanted network data charges are all common points to consider when developing network applications Also network connectivity availability strength and qu
198. ct User Input you created the settings screen and stored the data in SharedPreferences Now you will modify this screen to upload a copy of the player settings to the server in addition to storing it in SharedPreferences With this particular implementation the client device always has the last word in the data The application server simply stores a copy of the set tings This particular application does not have two way synchronization that would be beyond the scope of this book and take quite a bit longer than an hour to explain To keep the code readable and demonstrate important networking functionality By the __ we ve taken some liberties in the application architecture and have not always ay used the network in the most efficient fashion However the methods we have used allow us to demonstrate important features such as background updating progress indicators and more features of the AsyncTask class To communicate with the application server you can leverage the HttpClient package org apache http included in the Android SDK This package provides utilities for handling a wide variety of HITP networking scenarios within your appli cation You will learn how to use HttpGet to post query variables in the same way a web form submission would work using the HTTP GET method Then you ll learn how to use HttpPost to post form variables and upload the avatar graphic in the same way a web form might use the HTTP POST metho
199. ctivity retrieves the activity being tested Within the ActivityInstrumentationTestCase2 class the activity is created as it would nor mally be when the activity is launched Normally you would also override the tearDown method However for these tests you have no lingering items that need to be cleaned up JUnit tests must begin with the word test So to write specific tests you need to cre ate methods that begin with the word test followed by what you are testing First Maximizing Test Coverage 377 make sure the displayed Nickname field is consistent with the stored value in SharedPreferences Add the following code to QuizSettingsActivityTests to implement this test public void testNicknameFieldConsistency SharedPreferences settings getActivity getSharedPreferences QuizActivity GAME_PREFERENCES Context MODE_PRIVATE String fromPrefs settings getString QuizActivity GAME_PREFERENCES_NICKNAME String fromField nickname getText toString assertTrue Field should equal prefs value fromPrefs equals fromField The first few lines are all standard Android code that you should be familiar with By using the Android testing framework you are enabling using the various Android objects within the testing code The last line however is where the real test is performed The assertTrue method verifies that the second parameter actually is true If it s not the string is output in the results
200. ctly to the user s cell phone bill Instead Android Market uses Google checkout for processing payments Once an application is purchased the user owns it If your application requires a service fee or sells other goods within the application for example ringtones music ebooks you need to develop a custom billing mech anism Most Android devices can leverage the Internet so using online billing serv ices and APIs PayPal Google and Amazon to name a few is likely to be the common choice Check with your preferred billing service to make sure it specifically allows mobile use Currently the Android Market agreement does not allow for collecting payments Watch within an application Although there are applications available on the market that ut leverage this sort of thing for enhancing the appeal and user experience of the applications this is technically in violation of the current Android Market Developer Distribution Agreement Other forms of application distribution though may not be subject to these limitations Another method for making money from users is to have an ad supported mobile business model This is a relatively new model for use within applications as many older application distribution methods specifically disallowed it However Android has no specific rules against using advertisements within applications This shouldn t come as too much of a surprise considering the popularity of Google s
201. d The application server was written with HTML web forms in mind In fact the server was tested using a standard HTML form before the Android client was written By developing a web client before the Android client you ensure that the client server communication protocols used are standard and cross platform compatible When you use this procedure you know that any platform including Android that can handle web form style GET and POST methods will be compatible with this applica tion server This way the application can rely on the Apache HTTP libraries primarily the org apache http client package 282 By fhe waihi HOUR 16 Adding More Network Support The application server developed for use with this book is not part of the code on the website for this book However it is available for your use in open source form at http code google com p triviaquizserver Network upload operations can take some time Therefore all network related calls should be handled asynchronously separately from the main user interface thread This can be accomplished by using the Java Thread class or by using the Android AsyncTask class Also make sure to inform the user of lengthy opera tions by using a mechanism such as a ProgressBar control For more informa tion see Hour 15 Uploading Player Data with the HTTP GET Method The player data is submitted to the application server by using the HTTP GET method via
202. d Again EditText Password 2 Input TextView E g Passwords Match You can take advantage of the built in Button controls that can be configured for use with AlertDialog The three buttons need not be included in your layout design 189 FIGURE 11 4 Rough design for the Been There Done That password dialog FIGURE 11 5 Layout design for the Been There Done That settings screen 190 HOUR 11 Using Dialogs to Collect User Input Implementing the Password Dialog Layout Now it s time to implement the new layout that will be used by the password dialog You begin by creating a new layout resource file called password_dialog xml This layout file dictates the user interface of the dialog To create this file you follow these steps 1 Open the Eclipse layout resource editor and add a new file called res lay out password_dialog xml to the project 2 Adda LinearLayout control Set its id attribute to root and set its orienta tion attribute to vertical Set its layout_width and layout_height attrib utes to fill_parent All subsequent controls will be added inside this LinearLayout control 3 Add a TextView control to display the Password label text Then add an EditText control and set its id attribute to EditText_Pwd1 its maxLines attribute to 1 and its inputType attribute to textPassword 4 Add another TextView control to display the Password label text again Then add another EditText cont
203. d layout_height fill_parent gt lt TabWidget android id android id tabs 153 wyi 154 HOUR 9 Developing the Help and Scores Screens android layout_width fill_ parent android layout_height wrap_content gt lt FrameLayout android id android id tabcontent android layout_width fill_ parent android layout_height fill_parent gt lt ScrollView android id id ScrollViewAllScores android layout_width fill_ parent android layout_height fill_parent android scrollbars vertical gt lt TableLayout android id id TableLayout_AllScores android layout_width fill_parent android layout_height fill_parent android stretchColumns gt lt TableLayout gt lt ScrollView gt lt ScrollView android id id ScrollViewFriendScores android layout_width fill_ parent android layout_height fill_parent android scrollbars vertical gt lt TableLayout android id id TableLayout_FriendScores android layout_width fill_ parent android layout_height fill_parent android stretchColumns gt lt TableLayout gt lt ScrollView gt lt FrameLayout gt lt LinearLayout gt lt TabHost gt At this point save the scores xml layout file Watch __ At this point if you switch to the Layout view Eclipse may display a ut NullPointerException null error The Layout designer doesn t support TabHost controls as of Android 2 1 The layout will draw just fine in the emulator
204. d you must decide whether they are serious enough to stop the release process If you decide that an issue is serious enough to require another build you simply start the release process over again see Figure 23 2 FIGURE 23 2 The release candidate Test Build Log Bugs to testing cycle Thoroughly Defect Tracking Developer Implement Fixes to Defects from Defect produce New Build Tracking Log Bugs to Defect Tracking Test New Build Thoroughly Give Build the OK for Release Packaging and Signing an Application Now that you have a solid release candidate build that s tested and ready to go you need to package the application for publication This process involves generating the Android package file the apk file and digitally signing it The process of packaging and signing an application has never been easier The newest improvements to the Android plug in for Eclipse include a wizard for doing just that 388 Oat Diktow HOUR 23 Getting Ready to Publish Digitally Signing Applications Android application packages must be digitally signed for the Android package manager to install them Throughout the development process Eclipse has used a debug key to manage this process However for release you need to use a real digi tal signature one that is unique to you and your company To do this you must generate a private key A private key identifies the developer and is critica
205. d Debugging Applications 17 Running and Debugging Applications To build and debug an Android application you must first configure your project for debugging The ADT plug in enables you to do this entirely within the Eclipse devel opment environment Specifically you need to do the following gt Configure an Android Virtual Device AVD for the emulator gt Create a debug configuration for your project gt Build the Android project and launch the debug configuration When you have completed each of these tasks Eclipse will attach its debugger to the Android emulator or handset and you are free to debug the application as needed Managing Android Virtual Devices To run an application in the Android emulator you must configure an Android Virtual Device AVD The AVD profile describes the type of device you want the emulator to simulate including which Android platform to support You can specify different screen sizes and orientations and you can specify whether the emulator has an SD card and if so its capacity In this case an AVD for the default installa tion of Android 2 1 will suffice Here are the steps for creating a basic AVD 1 Launch the Android SDK and AVD Manager from within Eclipse by clicking on the little green Android icon with the arrow a on the toolbar You can also launch the manager by selecting Window Android SDK and AVD Manager in Eclipse 2 Click the Virtual Devices menu item on the left menu
206. d R id TextViewTopTitle logo1 clearAnimation TextView logo2 TextView findViewById R id 7TextViewBottomTitle logo2 clearAnimation stop other animations Animating All Views in a Layout In addition to applying animations to individual View controls you can also apply them to each child View control within a Layout such as TableLayout and each TableRow using LayoutAnimationController To animate View controls in this fashion you must load the animation create LayoutAnimationController configure it as necessary and then call the layout s setLayoutAnimation method For example the following code loads the cus tom_anim animation creates a LayoutAnimationController and then applies it to each TableRow in the TableLayout control Animation spinin AnimationUtils loadAnimation this R anim custom_anim LayoutAnimationController controller new LayoutAnimationController spinin TableLayout table TableLayout findViewById R id 7ableLayoutdO7 for int i 0 i lt table getChildCount i TableRow row TableRow table getChildAt i row setLayoutAnimation controller There is no need to call any startAnimation method in this case because LayoutAnimationController handles that for you Using this method the anima tion is applied to each child view but each starts at a different time The default is 50 of the duration of the animation which in this case would be 1 second This
207. d a Button control to launch a DatePickerDialog control The user selects the appropriate date and closes the dialog and the resulting date is displayed but not editable on the main settings screen within a TextView control gt The Gender setting is simply a choice between three values so a Spinner drop down control is most appropriate Figure 10 2 shows the layout design of the basic settings screen 164 FIGURE 10 2 Layout design for the Been There Done That settings screen HOUR 10 Building Forms to Collect User Input LinearLayout Vertical Orientation RelativeLayout ScrollView Vertical TextView Nickname EditText Nickname Input TextView Email EditText Email Input TextView Password LinearLayout Horizontal TextView Birth Date LinearLayout Horizontal TextView Gender Spinner Gender Input List Implementing the Settings Screen Layout 165 Implementing the Settings Screen Layout To implement the settings screen you begin by adding new resources to the project You then update the settings xml layout resource to reflect the settings screen design Adding New Project Resources Screens with form fields seem to rely on more resources than most other screen types You need to add a number of new resources to support the settings screen In addition to the string dimension and color resources you also need to add a new type of resource
208. d and how applica tions can define and enforce their own permissions You learned how to design con sistent user interfaces by using styles and themes You now know that Android devices have many powerful multimedia features including the ability to play and record audio and video and that it is feasible to develop 3D graphics intensive applications by using OpenGL ES Android applications can take advantage of the handy SQLite database features and can share data with other applications by accessing a content provider or by becoming a content provider Finally applica tions can access and interact with myriad underlying hardware sensors on a device Q What multimedia formats are supported on the Android platform A Different Android devices support different formats The platform supports a number of core formats but specific devices may also extend this list as they see fit For a complete list of supported formats see the Android documenta tion at http developer android com guide appendix media formats html Q Where can see code examples of the advanced features covered in this chapter A The implementation details of the features discussed in this chapter are beyond the scope of this book However we have written an advanced Android book titled Android Wireless Application Development You can also find many Android SDK examples on the Android developer website http developer android com Workshop 365 Workshop Q
209. d button In the emulator you should see an incoming SMS noti fication A Taking Screenshots of the Emulator or Handset One feature that can be particularly useful for debugging both handsets and emula tors is the ability to take screenshots of the current screen see Figure 2 7 34 HOUR 2 Mastering the Android Development Tools FIGURE 2 7 Using the B DOMS rot res valuesstongsam Etpse a sow al Lec Dore DDMS Screen Dior Bet Retector iy Movgate Senta Project Window Het me she Oorce pye 6 a dx B 2 56 PM Capture button 0 Dewes 5 TO JON fekal gome to take a Name gt ososesoz12024 Onine 21 updmel screenshot of Demsators354 Onine VanilaAVO 2 debog system n 600 the handset agrari us 4601 cOmancrokLinputmethod utn 136 8 android process accore 3 soot comandroxalarmcoct 199 3603 anod process media 70 su amp comandroidbookdroid1 us sit comandrod browser 404 ee O Emuiater Comet d Telephony Staas Telephony Actions d vy Try It Yourself Take a Screen Capture The screenshot feature is particularly useful when used with true handsets To take a screen capture follow these steps 1 In DDMS choose the device or emulator you want a screenshot of 2 On that device or emulator make sure you have the screen you want Navigate to it if necessary 3 Choose the multicolored square picture icon m to take a screen capture This launches a capture screen dialog 4 Within
210. d by a TabHost control with two tabs each of which will be a TableLayout control of scores one tab for all scores and one for friends scores Adding the TabHost Control To add tabbing support to the scores screen you include a TabHost control which is a container with child tabs each of which may contain some layout content TabHost is a somewhat complex control In order to configure it within an XML lay out file you need to follow a set of guidelines gt Include a TabHost control gt Ensure that there is a LinearLayout within the TabHost control gt Ensure that there is a specially named TabWidget control and FrameLayout control within the LinearLayout control gt Define the contents of each tab in the FrameLayout control Figure 9 5 shows the layout design for the scores screen Implementing the Scores Screen Layout 151 FIGURE 9 5 LinearLayout Vertical Orientation Layout design for the Been RelativeLayout There Done That scores ImageView a ImageView screen TabHost TabWidget FrameLayout TableRow Header TableRow One for each score TableRow Header TableRow One for each score Implementing the Scores Screen Layout To implement the scores screen you begin by adding new resources to the project Then you need to update the scores xml layout resource to reflect the scores screen design Adding New Project Resources In addition to the new string color and dimension re
211. d mobile development platforms on his tech blogs and is well known within the blogosphere Shane received a B S in Computer Science from the University of California A self admitted gadget freak Shane always has the latest phone or laptop He can often be found fiddling with the latest technologies such as Amazon Web Services Android iPhone Google App Engine and other exciting state of the art technologies that activate the creative part of his brain He also enjoys traveling the world with his geeky wife even if she did make him dive with 4 meter long great white sharks and almost get eaten by a lion in Kenya He admits that it was his fault they got attacked by monkeys in Japan that he snickered and whipped out his Android phone to take a picture when Laurie got her tongue stuck to that ice berg in Iceland and that he still hasn t learned his lesson about writing his own bio Other Publications by the Authors The authors have also published Android Wireless Application Development part of the Addison Wesley Developer s Library series as well as numerous online technical articles for http developer com http informIT com and their own Android blog http android book blogspot com Dedication To grandparents the world over especially those who are kind and generous bake awesome pecan pies and like to watch America s Most Wanted You are not a bother but a blessing And if you don t remember us telling you so don
212. d of the QuizGameActivity class mGameSettings getSharedPreferences GAME_PREFERENCES Context MODE_PRIVATE Wiring Up Game Logic 209 Now you can use SharedPreferences throughout the class as needed to read and write game settings such as the current question and the game score For example you could get the current question by using the getInt method of SharedPreferences as follows int startingQuestionNumber mGameSettings getInt GAME_PREFERENCES_CURRENT_QUESTION 0 Retrieving Parsing and Storing Trivia Question Data When the Been There Done That application runs out of questions to display to the user it attempts to retrieve a new batch of questions This architecture makes enabling networking for the application more straightforward in future hours because the parsing of the XML remains the same Each batch of questions arrives as a simple XML file which needs to be parsed You can store the current batch of questions in memory by using a simple but powerful data structure in this case a Hashtable member variable Declaring Helpful String Literals for Question Parsing Take a moment to review the XML format used by the question batches discussed earlier To parse the question batches you need to add several String literals to rep resent the XML tags and attributes to the QuizActivity java class public static final String XML_TAG_QUESTION_BLOCK questions public static final String XML_TAG_QUESTION
213. de relatively slow Internet connections compared to those found in personal computers Your Android applications must be responsive so you must always move all network operations off the main UI thread and onto a secondary worker thread The Android platform provides two methods for doing this gt AsyncTask This abstract class can be used to offload background operations from the UI thread easily This class is the first choice when handling opera tions that require some time and thus might affect the performance and responsiveness of your application gt Thread and Handler These classes can be used together to handle concurrent processing and communicating with the UI thread s message queue This advanced method allows more flexibility in terms of implementation but you as the developer are responsible for managing thread operations appropriately For the Been There Done That application the AsyncTask class is most appropriate because it s the most straightforward to implement Using AsyncTask The Android SDK includes the AsyncTask class android os AsyncTask to help manage background operations that will eventually post back to the UI thread Instead of using handlers and creating threads you can simply create a subclass of AsyncTask and implement the appropriate callback methods gt onPreExecute This method runs on the UI thread before background pro cessing begins gt doInBackground This met
214. de topics resources resources i18n html bestmatch How the Android Market Handles Locales The Android Market supports a subset of the locales available on the Android plat form Because the Android Market uses the Google Checkout system for payments only countries where this online marketplace is legal can be supported for paid applications Android Internationalization Strategies 327 For a complete list of the countries and languages supported by the Android Market see http market android com support bin answer py hl en amp answer 138294 Note that the Android Market differentiates between countries that allow only free appli cations and countries where developers can distribute fee based applications Developers must register to sell applications on the Android Market A complete Did you__ list of countries where developers of free Android apps may reside which is differ ow ent from where they may publish is available at http market android com support bin answer py hl en amp answer 136758 Android Internationalization Strategies Don t be overwhelmed by the permutations available to developers when it comes to internationalizing an application Instead give some thought to how important internationalization is to your application during the design phase of your project Develop a strategy that suits your specific needs and stick to it Here are some basic strategies to handle Android application inte
215. ders with certain features such as fine accuracy You can also use the getBestProvider method to return the most appropriate provider for a given set of criteria Each of these provider retrieval methods returns a list of names of location providers The best location provider for given set of criteria can be returned by name using the getProvider method You can use the LocationProvider class to inspect a given provider and see what features it has such as whether it supports altitude bearing and speed information and whether using it may incur a mone tary cost to the user Using Location Based Services 245 Getting the Last Known Location You can retrieve the last known location of the device as calculated by a specific provider by using the getLastKnownLocation method of the LocationManager class This location may not be current but it often gives you a good starting point and this data is returned quickly whereas trying to get a current satellite fix can often take quite some time You need not start the provider to get the last known location you simply need to request its last known result The getLastKnownLocation method returns a Location object Location recentLoc locMgr getLastKnownLocation LocationManager GPS PROVIDER The Location object can contain a number of interesting pieces of information regarding a location The information available depends on the abilities of the LBS provider For example mo
216. ding the information provided in the uses sdk settings O Disable the debuggable option O Confirm that all application permissions are appropriate Request only the permissions the application needs with uses permission and make sure to request permissions the application uses regardless of handset behavior with out them Readying Related Services for Release If the Android application relies on any external technologies or services such as an application server then these must also be readied for release Many large projects have a mock application server often called a sandbox as well as a real live server The release build needs to be tested against the live serv er just the way users would use it Testing the Application Release Candidate Once you have addressed all the prerelease issues discussed earlier you re ready to perform the release candidate build There is nothing particularly special about the general build process here except that you need to launch Run Configuration rather than Debug Configuration in Eclipse Packaging and Signing an Application 387 You should test the release candidate as rigorously as possible In addition to any regular testing you should verify that the application meets the criteria of the appli cation marketplaces such as the Android Market that where you want to publish to the app If you find any defects or issues with the release candidate buil
217. down during low memory situations by prudently managing activity state This means using the appropriate activity callbacks and following the recom mendations Most importantly applications should acquire resources only when necessary and release those resources as soon as possible Q How should I design an input form for an Android application A Mobile applications need to be ready to pause and resume at any time Typical web form style with various fields and Submit Clear and Cancel buttons isn t very well suited to mobile development Instead consider com mitting data as it is entered This will keep data housekeeping to a minimum as activity state changes without frustrating users 56 HOUR 3 Building Android Applications Workshop Quiz 1 Which of these screens does it make the most sense to show to a user first A Menu screen B Splash screen C Play screen 2 True or False Android provides a simple method for storing application set tings 3 What is the recommended way to get a context instance required by many Android calls A Context context Context this B Context context getAndroidObject CONTEXT C Context context getApplicationContext 4 True or False The android util Log class supports six types of logging Answers 1 B The splash screen shows the game logo before the user starts to play 2 True Simply use the SharedPreferences class to store simple settings 3 C T
218. down list on the Application tab with the Permissions tab features Use the Permissions tab to define the permissions required for the application to access the resources or APIs it needs The other is for defining permissions required by other applications to access exposed resources and APIs in your application Using the Instrumentation Tab You can use the Instrumentation tab see Figure 5 4 to declare any instrumentation classes for monitoring the application In the Name field you fill in the fully quali fied class name of the Instrumentation subclass for your application and for Target Package you provide the name of the package whose manifest file contains the lt application gt tag for the application to be monitored We will talk more about instrumentation and testing in a later chapter free Eat Ron Naeger sean Project Rear Window Hep nge amp SHE V 07 Q Baor Sere Attributes for android test InstrumentationTestRunner Instrumentation Attributes that can be supplied in an AndroidManitestxm instnamentation tag 4 child of the root manifest 129 android testUnstrumentatonTestunner Browse Configuring Basic Application Settings 81 Using the AndroidManifest xml Tab The Android manifest file is a specially formatted XML file You can edit the XML manually in the AndroidManifest xml tab of the manifest file resource editor see Figure 5 5 FIGURE 5 5 The A BRA FrOra BAGr Snar 3H AndroidManifest xml tab
219. droid database package ow In addition to programmatically creating and using SQLite databases developers can use the sqlite3 command line tool which is accessible through the ADB shell interface for debugging purposes 360 HOUR 21 Diving Deeper into Android Sharing Data with Other Applications An application can leverage the data available within other Android applications if they expose that data by becoming content providers You can also enable your application to share data within other applications by making it a content provider Using Content Providers The Android platform ships with some useful applications such as a contacts application and a browser application that expose some or all of their data by act ing as content providers An application can access the content of these applications by using the content provider data interface Some content providers provide only read access to data while others allow applications to create update and delete records such as contacts Most access to content providers comes in the form of queries to specific predefined URI object contained addresses Once formulated a query might return a list of con tacts or missed calls or it might return a specific record such as all contact informa tion for John Smith Applications can access content provider interfaces much as they would access any database You can think of a URI as an address to the location where
220. e 61 FIGURE 4 1 Android applica tions can use a variety of resources 62 Oitow ut HOUR 4 Managing Application Resources When resources are compiled their name dictates their variable name For exam ple a graphics file saved within the drawable directory as mypic jpg is refer enced as drawable mypic It is important to name resource names intelligently Consult the Android documentation for specific project directory naming conven tions Referencing Application Resources All application resources are stored within the res project directory structure and are compiled into the project at build time Application resources can be used pro grammatically They can also be referenced in other application resources Each time you save a resource file that is copy a resource file such as a graph ics file into the appropriate directory within Eclipse the R java class file is recompiled to incorporate your changes If you have not used the correct directory or file naming conventions you see a compiler error in the Eclipse Problems tab Application resources can be accessed programmatically using the generated class file called R java To reference a resource you must retrieve the application s Resources object using the getResources method and then make the appropri ate method call based on the type of resource you wish to retrieve For example to retrieve a string named hello defin
221. e To do this add a lt service gt block to the lt application gt section of the manifest file like this Working with Widget Background Operations 317 lt service android name QuizWidgetProvider WidgetUpdateService gt This tells the system that there is a service and where to find it Controlling the Service You now need to start the service from within the App Widget onUpdate method You can start a service in one of two ways either through a call to the Context startService method or through a call to the Context bindService method In this case you use the startService method by replacing the onUpdate method with the following code Override public void onUpdate Context context AppWidgetManager appWidgetManager int appWidgetIds Intent serviceIntent new Intent context WidgetUpdateService class context startService serviceIntent When a service has finished it s a good idea to stop it to free up valuable resources The App Widget will update only once every three hours Although you could leave the service around doing nothing you might as well stop it until it is needed again This is accomplished by placing the following call at the end of the run method of the Thread class you use to perform the background tasks if WidgetUpdateService this stopSelfResult startId Log e DEBUG_TAG Failed to stop service This call to the stopSelfResult method tells the service t
222. e http developer android com The Android documentation is divided into six sections see Figure 2 1 28 HOUR 2 Mastering the Android Development Tools gt SDK This tab provides important information about the SDK version installed on your machine One of the most important features of this tab is the release notes which describe any known issues for the specific installation This information is also useful if the online help has been upgraded but you want to develop to an older version of the SDK gt Dev Guide This tab links to the Android Developer s Guide which includes a number of FAQs for developers as well as step by step examples and a useful glossary of Android terminology for those new to the platform gt Reference This tab includes a searchable package and class index of all Android APIs provided as part of the Android SDK gt Blog This tab links to the official Android developer blog Check here for the latest news and announcements about the Android platform This is a great place to find how to examples learn how to optimize Android applications and hear about new SDK releases and Android Developer Challenges gt Videos This tab which is available online only is your resource for Android training videos Here you ll find videos about the Android platform developer tips and the Google I O conference sessions gt Community This tab is your gateway to the Android developer forums There ar
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224. e application tray and choosing About Phone or About device and then Status from the menus Here you will find important phone service Developing Network Applications in flight regulations Wi Fi There are a number of Wi Fi settings for when wireless networks are available for use Mobile Networks There are several settings for handling data services when roaming information such as the following gt gt Phone number for example 888 555 1212 Wireless network for example Verizon T Mobile Network type for example CDMA EVDO rev A or EDGE Signal strength for example 81 dBm 0 asu Service state for example In service Roaming state for example Roaming or Not roaming Mobile network state for example Connected You can cause a mobile device to lose its signal by placing it inside a cookie tin refrigerator microwave or in any other shielded area Doing so can be helpful for testing signal and network service loss Just don t leave a handset in the cold too long or you will drain the battery And don t use the microwave with the phone inside common sense for all 259 Dw 260 wai HOUR 15 Adding Network Support Accessing Network Services The Android platform has a wide variety of networking libraries Those accustomed to Java networking will find the java net package familiar There are also some helpful Android utility classes for various types of netwo
225. e as follows O Verify that the application icon various sizes of PNG is set appropriately This icon will be seen by users and is often used by marketplaces to display the application O Verify that the application label is set appropriately This represents the appli cation name as users will see it O Verify that the application version name is set appropriately The version name is a friendly version label that developers and marketplaces use 386 Oat Dw HOUR 23 Getting Ready to Publish The Android SDK allows the android versionName attribute to reference a string resource The Android Market does not You will see an error during the upload process when your package is validated The package will not be accepted O Verify that the application version code is set appropriately The version code is a number that the Android platform uses to manage application upgrades Consider incrementing the version code for the release candidate in order to differentiate it from the prerelease version of the application O Confirm that the application uses sdk setting is set correctly You can set the minimum target and maximum Android SDK versions supported with this build These numbers are saved as the API level of each Android SDK For example Android 2 1 is API level 7 The Android Market filters applications available to specific users based on the information provided in each application s manifest file inclu
226. e familiar getSystemService method of the application s Context object TelephonyManager telMgr TelephonyManager getSystemService Context TELEPHONY SERVICE Once you have a valid instance of TelephonyManager you can request the detailed information about the device and its telephony services Retrieving Call State Information You can use the TelephonyManager class to determine the call state of a cellular device by using the getCallState method This method tells you whether the phone is idle off the hook or currently receiving an incoming call You can also register to listen for changes in the phone state by using the listen method so that your application can receive a notification when an incoming call occurs You might use this information to screen specific phone numbers or prepare the application for the user to answer the phone Retrieving Network Type Information You can use the TelephonyManager class to query the network radio type of a cellu lar network by using the getNetworkType method This method tells you which network type the device is currently using such as GPRS EDGE or EVDO These and many other network types for example NETWORK_TYPE_GPRS are defined as con stants in the TelephonyManager class You can also register to listen for changes in the network type by using the listen method You might use this type of information to listen for a high speed data con nection and use the opportu
227. e favorite place feature will be incorporated into the settings screen AVATAR NICKNAME Picture 20 characters max EMAIL Will be used as unique account id PASSWORD Password requires entering twice to verify BIRTH DATE DOB requires entering Month Day Year GENDER Male Female or Prefer Not To Say FAVORITE PLACE Current Location or Search By Name Determining Favorite Place Feature Layout Updates Recall that the fields displayed on the settings screen are encapsulated within a ScrollView control This makes it easy to add a new setting at the bottom of the screen The favorite place feature will function much like the date of birth and pass word settings Designing the Favorite Place Feature To incorporate the favorite place design changes into the res layout settings xml layout file you need to add a new region to the settings screen below the gender Spinner control You begin by adding a TextView control to display the label of the new setting Then you add an inner LinearLayout control with a Button control to launch the dialog and a TextView control to display the resulting Favorite Place name Figure 14 2 shows the layout updates required by the favorite place feature LinearLayout Vertical Other Settings Like Gender Spinner LinearLayout Horizontal Designing the Favorite Place Dialog You need to give some thought to the custom favorite place picker dialog Again
228. e not enforced yet by the Android system An application ne should still request these permissions anyway for compatibility reasons ut Applications can define and enforce their own permissions This can be critically By the important for certain types of applications such as banking and commerce ay applications Managing Other Application Settings In addition to the features already discussed in this hour a number of other special ized features can be configured in the Android manifest file For example if your application requires a hardware keyboard or a touch screen you can specify these hardware configuration requirements in the Android manifest file You must also declare any other application components such as whether your application acts as a service provider content provider or broadcast receiver in the Android manifest file Summary The Android manifest file AndroidManifest xm1 exists at the root of every Android project It is a required component of any project The Android manifest file uses a simple XML schema to describe what the application is what its components are and what permissions it has The Android platform uses this information to manage the application Eclipse has a handy resource editor for managing Android manifest files 92 HOUR 5 Configuring the Android Manifest File Q Can application names be internationalized A Yes You simply define the android label attribute
229. e package names contain the hour number of the project they represent For example the package name for this hour is com android book triviaquiz6 This allows the projects to coexist on the handset and makes it easier to load all of them at once Adding Project Resources The Been There Done That project requires some additional resources Specifically you need to add a Layout file for each activity and a text string for each activity name and you need to change the application icon to something more appropriate Adding String Resources First you modify the strings xml resource file You delete the hello string and cre ate six new string resources one for each screen For example you should create a string called help with a value of Help Screen When you are done the strings xml file should look like this lt xml version 7 0 encoding utf 8 gt lt resources gt lt string name app_name gt Been There Done That lt string gt lt string name help gt Help Screen lt string gt lt string name menu gt Main Menu Screen lt string gt lt string 103 Oitow 104 Diktow HOUR 6 Designing an Application Framework name splash gt Splash Screen lt string gt lt string name settings gt Settings Screen lt string gt lt string name game gt Game Screen lt string gt lt string name scores gt Scores Screen lt string gt lt resources gt Adding Layout Resources Next you
230. e setOnClickListener method It is within the onClick method that you want to trigger DatePickerDialog to be launched However you are not quite ready to implement this Dialog window yet Instead you can drop in a useful little helper pop up mes sage called a toast A toast is a view that pops up in the foreground to display a message for a few Dig you _ seconds and then disappears ow 172 FIGURE 10 6 A Toast mes sage triggered by a button click FIGURE 10 7 A Spinner con trol closed left and open right HOUR 10 Building Forms to Collect User Input For example you could add a Toast message to the onClick method of the Button_DOB like this Toast makeText QuizSettingsActivity this TODO Launch DatePickerDialog Toast LENGTH_LONG show Figure 10 6 shows the resulting Toast message DM 8 33 pm Eeenrhereano j s tings Nickname Password Set Password No Password Set Birth Date gt n No Date Set TODO Launch DatePickerDialo Gend g Prefer Not To Say Working with Spinner Controls The Spinner control is basically the Android platform s version of a drop down list The control looks much like a drop down when closed see Figure 10 7 left but when the Spinner control is activated it displays a chooser window see Figure 10 7 right instead of drawing the drop down on the main screen r 7 Prefer Not To Say Prefer Not To Say s Male
231. e within the TelephonyManager class In addition to the wide variety of Android SDK networking libraries you have learned about thus far you can also access phone status and telephony information by using the TelephonyManager class The TelephonyManager class allows an Android application to access information about the phone carrier network cellular data connection subscriber identity module SIM and the device Android devices are not guaranteed to be mobile handsets Support for telephony service support may vary widely by phone type and service provider or may not be available at all Setting Phone State Permissions To access phone state information an Android application must have the appropri ate permissions granted within the Android manifest file Phone state information cannot be accessed or modified by an Android application unless it is granted the appropriate lt uses permission gt settings configured in the Android manifest file The following are common permission values used by applications leveraging phone state information gt android permission READ_ PHONE STATE gt android permission MODIFY_PHONE_STATE Accessing Phone Status Information 279 Retrieving Telephony Information Developers can leverage the TelephonyManager class android telephony TelephonyManager to access network status information about the device programmatically You can get an instance of TelephonyManager by using th
232. ed The other two are not SDK provided classes if they exist at all Exercises 1 Use the hashed unique device ID and the URL http tqs mamlambo com get player to perform a GET request to retrieve player info and load up the set tings with the data from the server Pass in just the playerId to get public data or pass in playerId and password to get all the data this is what you ll need for a full recovery 2 Add a new feature to the application to allow players to suggest for new trivia questions via SMS to the developer 3 Add a new feature to the application that allows players to suggest new trivia questions with images by uploading them via multipart MIME POST to http tqs mamlambo com suggest with a player identifier form field playerId question text form field question and question image form field questionImage with the image data done in the same way as for the avatar image used in this hour HOUR 17 Adding Social Features What You I Learn in This Hour gt Enhancing applications with social features gt Adding friend request support gt Displaying friends scores gt Integrating with third party social networking services In this hour you enhance the Been There Done That application by adding some social integration Specifically you modify the application to allow the user to keep track of other players scores You also review the many ways in which Android applications can
233. ed DatePickerDialog but it doesn t display unless the user clicks the appropriate Button control on the main settings screen The user triggers DatePickerDialog by pressing the Button control called Button_DOB You registered for click events on the Button_DOB control and currently make a Toast call Now you can change this to call the showDialog method which launches DatePickerDialog as shown in Figure 11 2 Button pickDate Button findViewById R id Button_DOB pickDate setOnClickListener new View OnClickListener public void onClick View v showDialog DATE_DIALOG_ID Working with Custom Dialogs Thursday January 21 1988 You can use the DateFormat class to format a date string The DateFormat class works well with Calendar dates as well as long format dates milliseconds since epoch For example to format a long date in the form January 1 2010 you could use the format method of the DateFormat method as follows String strDate DateFormat format MMMM dd yyyy dtDob Working with Custom Dialogs When the basic Dialog types do not suit your purpose you can create a custom dia log One easy way to create a custom dialog is to begin with AlertDialog and use an AlertDialog Builder class to override its default layout To create a custom dialog this way follow these steps 1 Design a custom layout resource to display in AlertDialog 2 Define the custom Dialog identifier in the act
234. ed Services The full implementation of these hints is available in the code provided at the book s website After you have implemented the framework to support the favorite place feature you can turn your attention to more interesting matters such as calculating the user s last known location and mapping GPS coordinates on a map Using Location Based Services Developers who enable LBS support in applications need to be aware of a number of issues First and foremost a user s location is personal information and subject to privacy concerns Second using LBS on a handset takes a toll on the device in terms of network data usage and battery life The Android system addresses these issues in part through permissions That said some of the burden of managing the impact of LBS features on the user and the user s device does fall on the developer Therefore here are some guidelines for using services such as LBS gt Enable LBS features only when they are needed and disable them as soon as they are no longer required gt Inform the user when collecting and using sensitive data as appropriate Many users consider their present or past locations to be sensitive gt Allow the user to configure and disable features that might adversely affect their experience when using your application For example develop a roam ing mode for your application to allow the user to enjoy your application without incurring huge f
235. ed as part of the Android SDK A Location based services B Geocoding and reverse geocoding services C Mapping services 4 True or False Because the emulator is not the real device there is no way to use LBS on the emulator Workshop 253 Answers 1 F Developers need to take all these concerns into account when developing LBS enabled applications 2 True Button controls included as part of a custom layout for a dialog are acceptable You should provide the appropriate View OnClickListener click handlers as part of the dialog building process Note that this is slightly differ ent from the DialogInterface OnClickListener click handlers required to handle the basic three dialog buttons available with AlertDialog 3 A and B The Android SDK includes support for LBS geocoding and reverse geocoding The services provided by specific devices vary Mapping services are provided as part of the Google API add on not as part of the stock Android SDK 4 False The emulator provides support for LBS services for some services the Google add on is needed and DDMS can be used to change location Exercises 1 Modify the favorite place picker dialog to take GPS latitude and longitude data that the user inputs 2 Modify the favorite place picker dialog to allow the user to configure the zoom level of the map shown 3 Modify the Been There Done That application to save altitude information along with the latitude and longi
236. ed in the strings xml resource file you would use the following method call String greeting getResources getString R string hello We will talk more about how to access different types of resources later in this hour To reference an application resource from another compiled resource such as a lay out file use the following format resource type resource name For example the same string used earlier would be referenced as follows string hello We will talk more about referencing resources later in the hour when we talk about layout files Working with Simple Resource Values 63 Working with System Resources Developers can access in addition to application resources Android system resources You can share many system resources across multiple applications for a common look and feel For example the Android system string resource class android R string contains strings for words such as OK Cancel Yes No Cut Copy and Paste To keep your application small and efficient always check out the system By the __ resources before adding generic resources to your project ay System resources are stored within the android package There are classes for each of the major resource types For example the android R string class contains the system string resources To retrieve a system resource string for ok for example you first need to use the static method of the Resources class called
237. eed to perform all testing Watch of Wi Fi APIs on a device ut Working with Bluetooth The Android SDK includes Bluetooth support classes in the android bluetooth package Here you ll find classes for scanning for Bluetooth enabled devices pair ing and handling data transfer Managing Power Settings and Battery Life Most mobile devices operate primarily using battery power To monitor the battery an application must have the BATTERY_STATS permission register to receive Intent ACTION_BATTERY_CHANGED BroadcastIntent and implement BroadcastReceiver to extract the battery information and take any actions required The following are some of the battery and power settings that can be monitored gt Whether a battery exists gt The battery health status charging state voltage and temperature gt The battery charge percentage and associated icon gt Whether the device is plugged in via AC or USB power An application can use the information about the device power state to manage its own power consumption For example an application that routinely uses a lot of processing power might disable features that use a lot of power in a low power situation 364 HOUR 21 Diving Deeper into Android Summary In this hour you learned about more advanced features of the Android platform You learned about some of the more advanced architectural components of Android applications such as how services and notifications can be use
238. ees gt Handle events such as low battery warnings and adjust how your application runs accordingly gt Consider including a custom privacy message as part of your application s usage terms to explain how any data collected from the user including the user s name and location information will and will not be used Not every Android device will have LBS hardware so you should not assume that all devices will be able to provide location information Using Location Based Services 241 A number of LBS features are available as part of the Android SDK but some of the most exciting features are actually part of the Google APIs add on This add on allows you to incorporate powerful features such as Google Maps functionality directly into Android applications Developers using the Google APIs add on must register for a special Google developer account and use a special API key Enabling Location Testing on the Emulator Many LBS features are available to developers without the special Google developer accounts and API keys For example you need a special API key to use Google Maps within an application but you do not need any special permission to launch an Intent object to view a location that can be matched to any Map applications on the device Creating an AVD with Google APIs and Applications You may have noticed that the basic Android installation the target platform cho sen when creating an AVD for use wit
239. eference HOUR 10 Building Forms to Collect User Input What You ll Learn in This Hour Designing and implementing the settings screen gt Working with EditText controls gt Working with Button controls gt Working with Spinner controls gt Saving form data with SharedPreferences In this hour you begin to implement the settings screen of the Been There Done That application The settings screen displays a form for entering application configuration information including the user s login and profile settings Different settings necessitate the use of different input controls including EditText Spinner and Button controls Finally you need to ensure that each setting is saved and stored in a persistent manner as part of the application s preferences Designing the Settings Screen The settings screen must allow the user to configure a number of game settings and save them Game settings may be text input fields drop down lists or other more complex controls You eventually want to handle social gaming with friends but you will deal with that requirement later For now you begin by implementing a simple settings screen with five basic game settings gt Nickname The name to be displayed on score listings This text field should be no more than 20 characters long an arbitrary but reasonable length for your purposes 162 FIGURE 10 1 Rough design for the Been There Done That settings screen
240. efore uploading your application package Answers 1 False You must create an authenticated developer account with Google before you can publish Android applications on the Android Market 2 A and D The Android Market the most popular Android application store allows developers to publish free and paid applications in a number of differ ent countries and it takes a 30 transaction fee for hosting applications 3 True You can sell your Android applications from a number of application shops including your own site Keep in mind that users need to enable instal lation of applications from unknown sources to install applications from unknown websites 4 None Although none of these are required some of them such as thoroughly testing your application are advisable Others might be useful for marketing purposes However none are actually required by the Android Market It s very open Exercises 1 Create a developer account for yourself on the Android Market 2 Browse through the Android Market on a handset or on the Android Market website Think of an idea for an application and determine what category and price range for that application in the Android Market 3 Go write a fabulous and exciting application and then share it with the world This page intentionally left blank APPENDIX A Configuring Your Android Development Environment This appendix walks you through the steps needed to install and configu
241. elected you ll be adding to that Instead select None or choose the Create a New Element at the Top Level in Application radio button at the top of the dialog 12 13 Click the Browse button next to the activity Name field Choose the new activ ity you created DroidActivity2 Save the manifest file Switch to the AndroidManifest xm1 tab to see what the new XML looks like You now have a new fully registered DroidActivity2 activity that you can use in your application 87 Sit Designating the Launch Activity You can use an Intent filter to designate an activity as the primary entry point of the application The Intent filter for launching an activity by default must be con figured using an lt intent filter gt tag with the MAIN action type and the LAUNCHER category In the Droid1 project the Android project wizard set DroidActivity as the primary launching point of the application lt activity android name DroidActivity android label string app_name gt lt intent filter gt lt action android name android intent action MAIN gt 88 HOUR 5 Configuring the Android Manifest File lt category android name android intent category LAUNCHER gt lt intent filter gt lt activity gt This lt intent filter gt tag instructs the Android system to direct all application launch requests to the DroidActivity activity Managing Application Permissions The Android platform
242. elephony information retrieving That game 104 adding to settings screens call state information 279 CDMA GSM information lt activity gt 86 87 165 166 lt application gt 279 280 declaring string literals for android debuggable network roaming question parsing 209 attribute 85 information 280 iti android description editing 16 N P network type attribute 85 explained 64 it information 279 android icon attribute 84 formatting 64 P SIM information 280 android label attribute styles 349 350 N l voice mail information 280 lt intent filter gt 87 88 supplementary materials TelephonyManager class i ae lt item gt 138 Android Mobile Application 55 getCallState method 279 g lt manifest gt Development website 3 getDeviceld method 279 424 425 lt permission gt 347 getNetworkType InformIT website 423 424 lt question gt 201 method 279 online Android resources lt questions gt 201 getPhoneType method 279 425 426 i i lt receiver gt 307 getSimOperator supported operating lt score gt 152 method 280 systems 409 i y lt uses library gt 82 getSimOperatorName system resources lt uses permission gt 88 method 280 definition of 59 lt uses sdk gt 83 getSimSerialNumber documentation for 74 TAKE_AVATAR_CAMERA_REQUEST method 280 referencing 63 intent 227 getSimState method 280 storing 63 TAKE_AVATAR_GALLERY_ getSubscriberld REQUEST intent 228 method 280
243. eloper android com gt Open Handset Alliance Android manufacturers operators and developers http www openhandsetalliance com gt Android Market Buy and sell Android applications http market android com publish gt OpenIntents An Android developer resource with a public intent registry as well as source for third party Android libraries and extensions http openintents org gt anddev org An Android developer forum http www anddev org gt FierceDeveloper A weekly newsletter for wireless developers http www fiercedeveloper com 426 APPENDIX C Supplementary Materials gt Stack Overflow Android A collaborative site for programmers with an offi cial section for Android http stackoverflow com questions tagged android gt Wireless Developer Network A daily news digest for the wireless industry http www wirelessdevnet com gt Developer com A developer oriented site that publishes technical articles http www developer com A aapt Android Asset Packaging Tool 39 AbsoluteLayout control 115 accelerometer 362 accessing application functionality with contexts 47 application preferences 46 47 layouts 71 LBS location based services last known location 245 providers 244 network services HTTP networking 261 262 network permissions 260 network status checking 260 261 phone status information retrieving telephony information 279 280 setting phone
244. en There Done That application in the emulator the main menu screen should look as shown in Figure 8 4 FIGURE 8 4 ame 8 36 2M The Been There eeenirnerenonemhs henna Done That ti MAIN MENU amp screeni customized ListView control 138 HOUR 8 Implementing the Main Menu Screen Working with Other Menu Types The Android platform has two other types of useful menu mechanisms gt Context menus A context menu pops up when a user performs a long click on any View object This type of menu is often used in conjunction with ListView controls filled with similar items such as songs in a playlist The user can then long click on a specific song to access a context menu with options such as Play Delete and Add to Playlist for that specific song gt Options menus An options menu pops up whenever a user clicks the Menu button on the handset This type of menu is often used to help the user handle application settings and such Because we ve been focusing on application screen navigation in this hour let s con sider where these different menus are appropriate in the Been There Done That application This application design lends itself well to an options menu for the game screen which would enable the user to pause while answering trivia questions to access the settings and help screens easily and then return to the game screen Adding an Options Menu to the Game Screen To add an options menu to the game screen
245. en should look as shown in Figure 7 3 You could stop here except that your splash screen still lacks pizzazz Also you need some way to transition from the splash screen to the main menu screen Working with Animation Version 1 0 0 Copyright 2010 Mamlambo Inc All Rights Reserved Working with Animation One great way to add zing to your splash screen would be to add some animation The Android platform supports four types of graphics animation gt Animated GIF images Animated GIFs are self contained graphics files with multiple frames gt Frame by frame animation The Android SDK provides a similar mecha nism for frame by frame animation in which the developer supplies the individual graphic frames and transitions between them see the AnimationDrawable class gt Tweened animation Tweened animation is a simple and flexible method of defining specific animation operations that can then be applied to any view or layout gt OpenGL ES Android s OpenGL ES API provides advanced three dimensional drawing animation lighting and texturing capabilities For your application the tweened animation makes the most sense Android pro vides tweening support for alpha transparency rotation scaling and translating moving animations You can create sets of animation operations do be done 119 FIGURE 7 3 The Been There Done That splash screen 120 ow HOUR 7 Implementing an Animated Splash Sc
246. enuActivity this QuizHelpActivity class else if strText equalsIgnoreCase getResources getString R string menu_item_settings Launch the Settings Activity startActivity new Intent QuizMenuActivity this QuizSettingsActivity class else if strText equalsIgnoreCase getResources getString R string menu_item_scores Launch the Scores Activity startActivity new Intent QuizMenuActivity this QuizScoresActivity class 3 The onItemClick method passes in all the information needed to determine which item was clicked In this case one of the simplest ways is to cast the view clicked to a TextView control because you know all items are TextView controls although you might want to verify this by using instanceof and just extract the specific Text control and map it to the appropriate screen Another way to deter mine which item was clicked would be to check the View control s id attribute Now if you implement the OnItemClickListener method and rerun the applica tion in the emulator you can use the main menu to transition between the screens in the Been There Done That application Customizing ListView Control Characteristics Now you re ready to customize the rather bland especially for a game menu default ListView control with a custom divider and selection graphics A ListView control has several parts a header the list of items and a footer By default the ListView control displays no
247. enus gt Animation sequences gt Shape drawables gt Styles and themes gt Custom layout controls When you are ready to use these other resource types consult the Android docu mentation for further details You will also want to consider reading a more advanced book on Android development There are several available including the Developer s Library book Android Wireless Application Development Written by yours truly this complete Android reference includes an exhaustive explanation of appli cation resources types with accompanying source code sample projects Summary Android applications can use many different types of resources including application specific resources and system wide resources The Eclipse resource editors facilitate resource management but XML resource files can also be edited manually Once 74 HOUR 4 Managing Application Resources defined resources can be accessed programmatically as well as referenced by name by other resources String color and dimension values are stored in specially for matted XML files and graphic images are stored as individual files Application user interfaces are defined using XML layout files Raw files which can include custom data formats may also be included as resources for use by the application Finally applications may include uncompiled binary files which are called application assets Q Can tell what all the system resources are just by their names
248. er as a friend in other words players who are watching this player s score The application server has the appropriate query implemented Use the same URL but add the variable followers and set it to the string true for example hnttp tqs mamlambo com scores jsp playerld amp followers true 3 Review the development API documentation of the third party social network ing service of your choice Consider implementing a simple feature for the Been There Done That application which accesses that networking service in an interesting way For example you might post a tweet to the player s Twitter feed each time that player answers a quiz question in the affirmative for example Player X has climbed Mount Everest 4 Add a feature to send a text message to the user s friend to challenge him or her to beat the user s score HOUR 18 Creating a Home Screen App Widget What You ll Learn in This Hour gt Designing and implementing an App Widget gt Handling App Widget user events gt Working with services In this hour you will create an App Widget for the Been There Done That application Specifically you will create a simple App Widget control that can be added to the user s Home screen to display the user s avatar nickname and score information and remind them to continue playing the game Designing an App Widget The Android SDK provides developers with an interesting way to provide func
249. er setText Next Text String Calling the setText method causes MyTextSwitcherFactory to generate a new TextView control with the String contents supplied in the setText parameter Working with ImageSwitcher The ImageSwitcher control enables an activity to animate between two ImageView controls You have included an ImageSwitcher control called ImageSwitcher_ QuestionImage in the layout of the game screen to display each trivia question image to the user Initializing an ImageSwitcher Control To initialize an ImageSwitcher control you simply set its ViewFactory and then use one of the three methods to set the image In this case you use the setImageDrawable method like so ImageSwitcher questionImageSwitcher ImageSwitcher findViewById R id ImageSwitcher_QuestionImage questionImageSwitcher setFactory new MyImageSwitcherFactory Drawable image getQuestionImageDrawable startingQuestionNumber questionImageSwitcher setImageDrawable image Unfortunately you cannot use the setImageURI method with a remote online URL with ImageSwitcher at this time Instead you need to perform a bit of extra work to download the image from the supplied URL and save it into an image Drawable object The implementation of the getQuestionImageDrawable method does just that private Drawable getQuestionImageDrawable int questionNumber Drawable image URL imageUr1 try Create a Drawable by decoding a stream from a
250. erride public void onItemSelected AdapterView lt gt parent View itemSelected int selectedItemPosition long selectedId TODO Save item index selectedItemPosition as Gender setting Other required overrides With certain versions of the Android SDK you might also need to provide the appropriate stub implementations for other required methods of the AdapterView OnItemSelectedListener class At this point save the QuizSettingsActivity java file and run the Been There Done That application in the Android emulator After the splash screen finishes choose the settings screen option The screen should look as shown in Figure 10 8 Saving Form Data with SharedPreferences DM G 8 33 pm g it Stings Nickname Password r pP Set Password No Password Set Birth Date Pick Date No Date Set Prefer Not To Say Saving Form Data with SharedPreferences You can use the persistent storage mechanism called SharedPreferences to store the application game settings Using these preferences you can save all the form values on the settings screen Defining SharedPreferences Entries Earlier you added a string to the QuizActivity base class for your game prefer ences public static final String GAME_PREFERENCES GamePrefs Now you need to add a preference String name for each of the values you want to store to the QuizActivity class public static final String GAME_PREFERENCES_NIC
251. es functionality for developing compiling packaging and deploying Android applica tions Specifically it provides the following gt The Android project wizard which generates all the required project files gt Android specific resource editors gt The Android SDK and AVD Android Virtual Devices Manager 10 wash Dw HOUR 1 Getting Started with Android gt The Eclipse DDMS perspective for monitoring and debugging Android applications gt Integration with Android LogCat logging gt Automated builds and application deployment to Android emulators and handsets gt Application packaging and code signing tools for release deployment Installing the Android SDK and Tools You will find all the details of how to install and configure your computer for Android application development in Appendix A Configuring Your Android Development Environment You will need to install and configure Eclipse the Android SDK and the ADT plug in for Eclipse You may also need to install the USB drivers for any Android handsets you will be using for development Now let s take some of these features for a spin Creating Android Projects The Android Project Wizard creates all the required files for an Android application Open Eclipse and follow these steps to create a new project 1 Choose File New Android Project or click the Android Project creator icon which looks like a folder with the letter
252. es of the Android SDK Next you design and implement the scores screen With its more complicated requirements the scores screen is ideal for trying out the tab set control called TabHost Finally you test the scores screen by parsing mock XML score data and display ing the appropriate information on each tab 144 FIGURE 9 1 Rough design for the Been There Done That help screen HOUR 9 Developing the Help and Scores Screens Designing the Help Screen The help screen requirements are straightforward This screen must display a large quantity of text and have scrolling capability Figure 9 1 shows a rough design of the help screen Game Help Text Vertical Scrolling You want the application screens to share some common features Therefore you can have the help screen mimic some of the menu screen features such as a header To translate your rough design into the appropriate layout design you need to update the res layout help xml layout file and the QuizHelpActivity class You want the same sort of title header you used in the menu screen using a RelativeLayout followed by a TextView control with scrolling capability Figure 9 2 shows the layout design for the help screen Implementing the Help Screen Layout 145 LinearLayout Vertical Orientation opis r for the Been RelativeLayout There Done That help TextView Implementing the Help Screen Layout To implement the help screen you begin by addin
253. es subdirectory Managing and Sharing Data 359 gt openFileOutput Creates or opens an application file for writing in the files subdirectory gt deleteFile Deletes an application file by name from the files subdi rectory gt fileList Lists all files in the files subdirectory gt getFilesDir Retrieves a File object for the files subdirectory gt getCacheDir Retrieves a File object for the cache subdirectory gt getDir Creates or retrieves a File object for a subdirectory by name You can browse the Android file system of the emulator or a connected device by Dig you using the DDMS File Explorer Ow Storing Structured Data in a SQLite Database Android applications can have a locally accessible private application database powered by SQLite SQLite relational databases are lightweight and file based ideal for mobile devices The Android SDK includes a number of useful SQLite database management classes The SQLite support available on the Android platform is found in the android database sqlite package Here you ll find utility classes for the following gt Creating versioning and managing databases Vv Building proper SQL queries gt Iterating through query results with Cursor objects gt Processing database transactions gt Handling specialized database exceptions Android has built in SQLite support However you will also find generic database tee classes within the an
254. essing HTTP networking 261 262 network permissions 260 network status checking 260 261 network status checking 260 261 network type information retrieving 279 Networklnfo class 261 New Android Project dialog Create New Project in Workspace button 10 Create Project from Existing Sample button 13 Create Project from Existing Source button 13 New menu commands Android Project 10 Class 415 next method 156 Notification object 349 NotificationManager system service 349 notifications 348 349 How can we make this index more useful Email us at indexes samspublishing com 448 objects o objects Context getConfiguration method 329 getSystemService method 261 279 Notification 349 RemoteViews 311 SensorManager 362 Service creating 316 317 starting stopping 317 318 WifiManager 363 onActivityResult method 49 52 224 225 228 onAnimationEnd method 123 onBind method 316 onCancelled method 270 271 OnClickListener method 222 onCreate method 49 171 176 208 268 316 onCreateDialog method 53 183 185 190 296 onCreateOptionsMenu method 139 onDateSet method 185 onDeleted method 309 onDestroy method 49 177 316 onDisabled method 309 onDoubleTap gesture 351 onDoubleTapEvent gesture 351 onDown gesture 351 onEnabled method 309 onFling gesture 352 onltemClick method 135 136 OnltemClickLi
255. est class part of the java security package conveniently provides this ability MessageDigest sha MessageDigest getInstance SHA byte enc sha digest uniqueId getBytes The book s website contains the full implementation of this example and sends the hashed value to the server Handling Player Score Uploads To upload the player score information to the application server you might want to add another AsyncTask subclass to the QuizGameActivity class But why not just update the existing QuizTask to communicate the player s score to the application server each time the game downloads new questions This can help reduce latency and increase network efficiency You can simply add the score information as a query variable of the request being sent to the server within the doInBackground method of the QuizTask class You use the following code to accomplish this SharedPreferences settings getSharedPreferences GAME_PREFERENCES Context MODE_PRIVATE Integer playerId settings getInt GAME_PREFERENCES PLAYER _ID 1 if playerId 1 Log d DEBUG_TAG Updating score Integer score settings getInt GAME_PREFERENCES_SCORE 1 if score 1 pathToQuestions amp updateScore yes amp updateId playerId amp score score The code is added right after the pathToQuestions URL is created but before it s used so it can be updated 286 Ditow FIGURE 16 2 Uploading the avatar
256. estions that have downloaded Q Where can I find out more about the network protocol support available on the Android platform A Three good networking packages to browse within the Android SDK are android net java net and org apache Workshop Quiz 1 Where can you find out information about an Android handset s network status A On the status bar B In the Android Settings application C By calling the getHandsetNetworkStatus method of the NetStatus class 2 True or False The Android emulator cannot simulate network speed and latency similar to that found on real Android devices 3 True or False You must use Google App Engine for Android application servers Workshop 275 4 Which of the following is a not a network protocol or technology that Android can use A HTTP B HTTPS C TCP D IP E Raw Sockets RS Answers 1 A and B Some basic information about the device s network status is indeed shown on the status bar but you can get detailed network status information from the Android Settings application 2 False The Android emulator has a number of settings for simulating network speed and latency 3 False You can use any server technology standard you want to implement an application server to interact with the Android application Google App Engine is only one of many such technologies 4 Trick question All of the listed protocols or network technologies can be used within Android a
257. et and then click the little green bug IEA to attach a debugger to that process You need to have the source code in your Eclipse workspace for this to work properly This works only in Eclipse not in the standalone version of DDMS Debugging Applications with DDMS 31 Browsing the Android File System You can use the DDMS File Explorer to browse files and directories on the emulator or a device see Figure 2 4 You can copy files between the Android file system and your development machine by using the push and pull de icons FIGURE 2 4 Using the ae Ge neeee BOR 0 Re o a EE Teas O Heap Aoaton Tracer CAERE DDMS File ak A rsa Explorer to VaniiigAVD 2 1 cebu 2010 04 05 1841 1970 01 01 0000 browse system Soriano fonts on the SE handset 42 1409 2009 12 19 6035 2009 12 19 0O45 2009 12 19 0038 6880 2009 11 24 1738 wrer 191032 2009 09 21 190044 2009 09 21 30819 2003 09 21 117072 2009 09 21 154836 2009 09 21 189916 2009 09 21 177176 2009 09 21 172532 2009 09 21 2009 12 19 2009 12 19 2010 04 13 OP 12 19 2009 12 19 0P 12 19 REGEEEEEEEEEE You can also delete files and directories by using the minus button or just pressing Delete There is no confirmation for this Delete operation nor can it be undone Interacting with Emulators DDMS can send a number of events such as simulated calls SMS messages and location coordinates to specific emulator instances These features are fou
258. etermined the latitude and longitude of a location you can launch the Maps application or any application that handles this type of data using the following URI format string geo lat lon Here s an example String geoURI String format geo sf f lat lon This special URI can also include a zoom level which is a number between 1 and 23 where zoom level 1 shows the whole planet and zoom level 23 zooms in all the way often way too far for map resolution To include a zoom level use the follow ing URI format string geo lat lon z level Here s an example String geoURI String format geo f f z 10 lat lon When you have a properly formatted URI you can use the parse method to gen erate the Uri and use it with the ACTION_VIEW intent as follows Uri geo Uri parse geoURT Intent geoMap new Intent Intent ACTION_VIEW geo startActivity geoMap Working with Maps 249 If there are applications on the device that handle geo format URIs the appropriate application for example the Google Maps application will launch as the new fore ground activity and show the location After the user has looked at the map he or she can return to the calling application by pressing the Back button By using the Geocoder class and an intent to launch the Google Maps application you can complete the favorite place picker dialog including the Map It Button con trol as shown in Figure 14 10 Sae sorm et
259. etting that can be modified by the mobile opera tor For example a German mobile operator might make the default locale Deutsch Deutschland for its shipping handsets An American mobile operator would likely set the default locale to English American and also include an option for the locale Espa ol Estados Unidos thus supporting American English and Spanish of the Americas A user can change the system wide setting for locale in the Settings application The locale setting affects the behavior of applications installed on the handset Try It Yourself To change the locale on a handset perform the following steps 1 From the Home screen click the Menu button and choose Settings 2 From the Settings menu select the Language amp Keyboard option 3 Choose Select Locale and select a locale The Android platform immediately changes the locale on the system For example if you choose Espa ol you see that many of the menus on the Android platform are now in Spanish Take care to remember these steps as you will have to navigate back to the locale settings in the foreign language you chose How Applications Handle Locales Now let s look at how the system wide locale setting affects each Android applica tion When an Android application uses a project resource the Android operating system attempts to match the best possible resource for the job at runtime In many cases this means checking for a resource in the specific
260. ew such preferences SharedPreferences settings getSharedPreferences GamePrefs MODE_PRIVATE SharedPreferences Editor prefEditor settings edit prefEditor putString UserName Spunky prefEditor putBoolean HasCredits true prefEditor commit To retrieve preference settings you simply retrieve SharedPreferences and read the values back out SharedPreferences settings getSharedPreferences GamePrefs MODE_PRIVATE String userName settings getString UserName Chippy Jr Default Accessing Other Application Functionality Using Contexts The application context provides access to a number of top level application fea tures Here are a few more things you can do with the application context gt Launch Activity instances gt Retrieve assets packaged with the application gt Request a system level service provider for example location service v Manage private application files directories and databases gt Inspect and enforce application permissions The first item on this list launching Activity instances is perhaps the most com mon reason you will use the application context Working with Activities The Activity class is central to every Android application Much of the time you ll define and implement an activity for each screen in your application In the Chippy s Revenge game application you have to implement five different Activity classes In the course of playin
261. ewInstance newPullParser scores setInput xmlUrl openStream null if scores null processScores scores return result Here you simply generate the appropriate URL to the application server and use the openStream method to access the data stream from a remote application server Downloading and Displaying Scores 269 After you call the setInput method of the Xm1PullParser you can use that Xm1PullParser just as you used the one pointed at local resource data Now move the processScores method into the ScoreDownloaderTask class Now you will want to update the method which simply takes the Xm1PullParser and parses the XML to publish scores as they are parsed using the publishProgress method private void processScores XmlPullParser scores throws XmlPullParserException IOException int eventType 1 boolean bFoundScores false Find Score records from XML while eventType XmlResourceParser END DOCUMENT if eventType XmlResourceParser START_TAG Get the name of the tag eg scores or score String strName scores getName if strName equals score bFoundScores true String scoreValue scores getAttributeValue null score String scoreRank scores getAttributeValue null rank String scoreUserName scores getAttributeValue null username publishProgress scoreValue scoreRank scoreUserName eventType scores next Handle no s
262. ferences The Been There Done That trivia game needs a simple way to store some basic state information and user data You can use Android s shared preferences android content SharedPreferences to add this functionality You can access shared preferences by name from any activity within the applica tion Therefore declare the name of your set of preferences in the base class QuizActivity so that they are easily accessible to all subclasses public static final String GAME_PREFERENCES GamePrefs There is no limit to the number of sets of shared preferences you can create You can use the preference name string to divide preferences into categories such as game preferences and user preferences How you organize shared preferences is up to you To add shared preferences to the application take the following steps 1 Use the getSharedPreferences method to retrieve an instance of a SharedPreferences object 2 Create a SharedPreferences Editor object to modify preferences 3 Make changes to the preferences by using the editor 4 Commit the changes by using the commit method in the editor Saving Specific Shared Preferences Each preference is stored as a key value pair Preference values can be the following types gt Boolean gt Float gt Integer Running the Game Prototype 107 gt Long gt String After you have decided what preferences you want to save you need to get an insta
263. ffset attrib ute to 2500 milliseconds This means that this animation will actually take 5 sec onds total It waits 2 5 seconds and then fades in for 2 5 seconds Because 5 seconds is long enough to display the splash screen you should plan to listen for fade_in2 to complete and then transition to the main menu screen Finally you need some fun animation sequence for the TableLayout graphics In this case your animation set contains multiple simultaneous operations a rotation some scaling and an alpha transition As a result the target View spins into exis tence The custom_anim xml file looks like this Working with Animation lt xml version 7 0 encoding utf 8 gt lt set xmlns android http schemas android com apk res android android shareInterpolator false gt lt rotate android fromDegrees 0 android toDegrees 360 android pivotX 50 android pivotY 50 android duration 2000 gt lt alpha android fromAlpha 0 0 android toAlpha 7 0 android duration 2000 gt lt alpha gt lt scale android pivotX 50 android pivotY 50 android fromxXScale 7 android fromYScale 7 android toxXScale 7 0 android toYScale 7 0 android duration 2000 gt lt set gt As you can see the rotation operation takes 2 seconds to rotate from O to 360 degrees pivoting around the center of the view The alpha operation should look familiar it simply fades in over the same 2 second period
264. file comes up With the previous tip you can now have two different views of the same file Ever feel like you get far too many tabs open for files you re no longer editing I do There are a number of solutions to this problem First you can right click a file tab and choose Close Others to close all other open files besides the chosen one You can quickly close specific tabs by middle clicking with a mouse on each tab This even works on a Mac with a mouse that can middle click such as one with a scroll wheel Finally you can use the Eclipse setting that limits the number of open file editors 1 Open Eclipse s Preferences dialog 2 Expand General choose Editors and check Close Editors Automatically 3 Edit the value in Number of Opened Editors Before Closing I find eight to be a good number to use for the Number of Opened Editors Before Closing option to keep the clutter down but have enough editors open to still get work done and have reference code open Note also that if you check Open New Editor under When All Editors Are Dirty or Pinned more files will be open if you re actively editing more than the number chosen Thus this setting doesn t affect pro ductivity when you re editing a large number of files all at once but can keep things clean during most normal tasks Renaming Almost Anything Eclipse s Rename tool is quite powerful It can be used to rename variables methods class names and more Most often
265. ft blank HOUR 24 Publishing on the Android Market What You l Learn in This Hour gt Selling Android applications to the Android Market gt Exploring Android application publishing options gt Protecting your intellectual property Congratulations You ve made it to the final hour and you ve learned how to build and test an Android application The next logical step is to publish your application In this hour you learn how to publish an Android application on the popular Android Market and explore other publishing options Unlike other mobile platforms Android supports paid distribution free distribution and even self distribution options This gives a developer wonderful flexibility for getting appli cations into the hands of users with fewer hurdles than most platforms and a greater number of choices for users Selling on the Android Market At this time the Android Market is the primary mechanism for distributing Android appli cations This is where typical users purchase and download applications As of this writ ing the Android Market is available on most Android handsets Therefore in this hour we show you how to check a package for preparedness sign up for a developer account and submit your application for sale on the Android Market 396 FIGURE 24 1 The Android Market publish er sign up page HOUR 24 Publishing on the Android Market Signing Up for a Developer Account To publish app
266. g HttpPost request new HttpPost TRIVIA_SERVER_ACCOUNT_EDIT request setEntity entity HttpClient client new DefaultHttpClient ResponseHandler lt String gt responseHandler new BasicResponseHandler String responseBody client execute request responseHandler if responseBody null amp amp responseBody length gt Log w DEBUG_TAG Unexpected response from avatar upload responseBody return null You need to create a browser compatible multipart MIME object by using the MultipartEntity class and add two parts one for the avatar file contents and one for the unique player identifier that the avatar belongs to Next you generate an HttpPost object with the URL to the application server Finally you set the entity within the HttpPost object by using the setEntity method To send the request and retrieve the response you use the HttpClient and ResponseHandler classes as usual Workshop Summary In this hour you modified the Been There Done That application to upload game data including player settings avatar and scores to a remote application server You also learned how to retrieve telephony information such as network type and roaming information via TelephonyManager In addition you learned how to use the HTTP GET and POST methods with HttpClient when uploading data to a server Q How can I avoid uploading user data in plain text A There are many ways you can pr
267. g in the phone via USB and it will show up when you launch an application via Eclipse Notes on Windows Installations You need to install Android USB drivers You will find them as one of the packages in the Android SDK and AVD Manager under USB Driver Package Alternatively you can download them separately from http developer android com sdk win usb html After you unzip the drivers connect your phone to your computer via the USB cable and select the drivers you want to install Notes on Mac OS X Installations On a supported Mac all you have to do is plug in the USB cable to the Mac and the device There is no additional configuration needed Notes on Linux OS Installations Ubuntu Linux installations require a rules file using the following steps 1 Log in as root administrator 2 Create the file etc udev rules d 50 android rules 3a For Gutsy 7 10 Hardy 8 04 Ubuntu Linux installations the file should con tain SUBSYSTEM usb SYSFS idVendor O0bb4 MODE Q666 3b For Dapper 6 06 Ubuntu Linux installations the file should contain SUBSYS TEM usb_device SYSFS idVendor 0bb4 MODE 0666 4 Enter chmod a rx etc udev rules d 5Q0 android rules Py Way APPENDIX B Eclipse IDE Tips and Tricks In this appendix a variety of tips and tricks for Eclipse are offered for your enjoyment and benefit These tips and tricks are geared toward tasks performed frequently while develop ing Android a
268. g an application for publication is called the release process Figure 23 1 The release process is an exciting time The application is humming all those trou blesome bugs have been resolved within reason at least and you re ready to put your app in front of users The final build you perform the build you expect to deliver to users is called the release candidate build The release candidate build should be rigorously tested and verified before it reaches users hands If the release candidate build passes every test it becomes the release build the official build for publication 384 HOUR 23 Getting Ready to Publish FIGURE 23 1 An overview of Prepare for the release Build process Perform Build Release Candidate Fix Bugs Test Build Got Bugs Thoroughly Package and Sign Package Test Packaged Release Candidate Publish Release By the Different people use different terminology for the release process Different soft ay ware methodologies impose different terms Some companies have code names for such events such as going gold Over the years we ve settled on release and release candidate because regardless of the methodology of choice the terms are pretty self explanatory to most developers To publish an Android application take the following steps 1 Prepare and perform a release candidate build of the application 2 Test the application release candidate thoroug
269. g is an integer representing the mini mum Android SDK version required Table 5 1 shows the Android SDK versions available for shipping applications TABLE 5 1 Android SDK Versions Available Android SDK Version Value Android 1 0 SDK 1 Android 1 1 SDK Android 1 5 SDK Android 1 6 SDK Android 2 0 SDK Android 2 0 1 SDK Android 2 1 SDK N O OO fF WO DN For example in the Droid1 project you specified that the minimum SDK as Android 2 1 SDK lt uses sdk android minSdkVersion 7 gt Each time a new Android SDK is released you can find the SDK version number in Did you the SDK release notes This is often referred to as the API Level within the tools ow especially the Android SDK and AVD Manager 84 HOUR 5 Configuring the Android Manifest File Naming an Application The lt application gt tag android label attribute is a string representing the appli cation name You can set this name to a fixed string as in the following example lt application android label My application name gt You can also set the android label attribute to a string resource In the Droid1 project you set the application name to the string resource as follows lt application android label string app_name gt In this case the resource string called app_name in the strings xml file supplies the application name Providing an Icon for an Application The lt application gt tag attribute called android icon is a
270. g new resources to the project Then you must update the help xml layout resource to reflect the help screen design Adding New Project Resources In addition to any new string color and dimension resources you use within the layout for the help screen you also need to add a new type of resource a raw file resource file In this instance you include a text file called res raw quizhelp txt that includes a number of paragraphs of help text which you will display in the main TextView control of the help screen 146 Dw Dw Diiw HOUR 9 Developing the Help and Scores Screens You can also include large bodies of text as string resources This can be helpful for internationalization Using a string resource also allows you to take advantage of the built in support for some HTML style tags In this case we ve used a text file to demonstrate the use of raw file resources Updating the Help Screen Layout The help xml layout file dictates the user interface of the help screen At this point you open the Eclipse layout resource editor and remove all existing controls from the layout You then follow these steps to generate the layout you want based on the screen design 1 Adda new LinearLayout control and set its background attribute to draw able bkgrnd All subsequent controls will be added inside the LinearLayout control 2 Add the same header you created in the menu xml layout It should contain a RelativeLayo
271. g the game the user transitions from one activity to the next interacting with the layout controls of each activity 48 Dw HOUR 3 Building Android Applications Launching Activities There are a number of ways to launch an activity including the following gt Designating a launch activity in the manifest file gt Launching an activity using the application context gt Launching a child activity from a parent activity for a result Designating a Launch Activity in the Manifest File Each Android application must designate a default activity within the Android manifest file If you inspect the manifest file of the Droid1 project you will notice that DroidActivity is designated as the default activity Other Activity classes might be designated to launch under specific circum stances You manage these secondary entry points by configuring the Android manifest file with custom filters In Chippy s Revenge SplashActivity would be the most logical activity to launch by default Launching Activities Using the Application Context The most common way to launch an activity is to use the startActivity method of the application context This method takes one parameter called an intent We will talk more about the intent in a moment but for now let s look at a simple startActivity call The following code calls the startActivity method with an explicit intent startActivity new Intent getApplicationContext
272. gathering information about the current state of a network This is useful for determining whether a network connection is avail able before trying to use a network resource By validating network connectivity before attempting to make a connection you can avoid many of the failure cases Accessing Network Services 261 common in mobile device networking applications and provide your end users with a more pleasant user experience Retrieving Network Status Information Programmatically Applications need to register the android permission ACCESS_NETWORK_STATE per mission in the Android manifest file to read the network status of the device To alter the network state of the device the application must also have the android per mission CHANGE_NETWORK_STATE permission Developers can leverage the ConnectivityManager class android net ConnectivityManager to access network status information about the device programmatically You can get an instance of ConnectivityManager by using the familiar getSystemService method of the application s Context object ConnectivityManager conMgr ConnectivityManager getSystemService Context CONNECTIVITY_SERVICE When you have a valid instance of ConnectivityManager you can request the mobile cellular network information by using the getNetworkInfo method NetworkInfo netInfo conMgr getNetworkInfo ConnectivityManager 7TYPE_MOBILE The NetworkInfo class android net NetworkInfo
273. gt lt color name app_text_color gt FFE4C4 lt color gt lt resources gt The Android system supports 12 bit and 24 bit colors in RGB format Table 4 2 lists the color formats that the Android platform supports TABLE 4 2 Color Formats Supported in Android Format Description Example RGB 12 bit color 00F blue ARGB 12 bit color with alpha 800F blue alpha 50 RRGGBB 24 bit color FFOOFF magenta AARRGGBB 24 bit color with alpha 80FFOOFF magenta alpha 50 The following code retrieves a color resource named app_text_color using the getColor method int textColor getResources getColor R color app text_color There are lots of color pickers on the web For example http html color codes info provides a simple color chart as well as a clickable color picker Working with Dimensions To specify the size of a user interface control such as a Button or TextView control you need to specify different kinds of dimensions You tag dimension resources with the lt dimen gt tag and store them in the resource file res values dimens xml This XML resource file is not created by default and must be created manually Here is an example of a dimension resource file lt xml version 7 0 encoding utf 8 gt lt resources gt lt dimen name thumbDim gt 1 Opx lt dimen gt lt resources gt Each dimension resource value must end with a unit of measurement Table 4 3 lists the dimension u
274. h in and any other words of wisdom you re willing to pass our way You can email or write me directly to let me know what you did or didn t like about this book as well as what we can do to make our books stronger Please note that I cannot help you with technical problems related to the topic of this book and that due to the high volume of mail I receive I might not be able to reply to every message When you write please be sure to include this book s title and author as well as your name and phone or email address I will carefully review your comments and share them with the author and editors who worked on the book Email feedback samspublishing com Mail Mark Taub Editor in Chief Sams Publishing 800 East 96th Street Indianapolis IN 46240 USA Reader Services Visit our website and register this book at http informit com register for convenient access to any updates downloads or errata that might be available for this book Introduction The Android platform is packing some serious heat these days in the mobile marketplace and gaining traction worldwide The platform has seen numerous advancements in terms of SDK functionality handset availability and feature set A wide diversity of Android handsets and devices are now shipping and finally in consumers hands and we re not just talking about phones Android has begun to ship on netbooks Internet tablets such as the ARCHOS 5 ebook readers like the Barnes
275. h the emulator does not include the Maps application To use the Android Maps application developed by Google with the Emulator you need to create an Android AVD with the Google APIs target platform Because you want to add some mapping features to the Been There Done That application you need to create a new AVD for this target platform Configuring the Location of the Emulator Unfortunately the Android emulator just pretends to be a real device that is it doesn t actually have any hardware internals so it cannot for example determine its current location via satellites Instead you have to seed the location information to the specific emulator instance The easiest way to configure your emulator is to use the DDMS perspective in Eclipse You need the latitude and longitude of the location you want the emulator to use You can use Google Maps to determine GPS coordinates To find a specific set of Dig you _ coordinates go to http maps google com and navigate to the location you ow desire Center the map on the location by right clicking the map and then choose the option to link to the map usually in the top right corner of the screen above the map Copy the link URL which has the GPS coordinates as part of the query string to a text file Find the last 11 query variable which should represent the latitude and longitude of the location For example the west edge of Yellowstone Lake in Yellowstone National Park has the
276. handset may have the ability to handle this operation The Android operating sys tem attempts to match the most appropriate activity to handle the request However if you want the user to be shown a list of applicable activities or applica tions to handle the request simply wrap your intent within another intent called ACTION_CHOOSER You often see this mechanism used with common applications such as messaging applications for example Which application do you want to use to send this message You can wrap an intent within a chooser by using the createChooser method like this Intent createChooser innerIntent Choose which application to handle this Although most handsets have only one image capturing application as a develop er you are better off not making assumptions of this sort The ACTION_IMAGE_CAPTURE intent action causes the camera application to launch allows the user to take a photograph and returns the photo By default a small bitmap is returned and it is suitable for your avatar Within a specific case statement of the onActivityResult method for the request code Working with Image Media 227 TAKE_AVATAR_CAMERA_REQUEST you can retrieve the bitmap by inspecting the Intent parameter called data as follows Bitmap cameraPic Bitmap data getExtras get data You can then pass the bitmap graphic into your helper method saveAvatar Working with the Gallery Android has a standard
277. hardware Camera class to connect to the Camera service on the device ow configure settings and take photos and video Your application will require the android permission CAMERA permission to access the camera hardware on the handset By far the simplest way to include photo taking abilities in an application is by launching the ACTION_IMAGE_CAPTURE intent For example you could add the fol lowing code to the onClick method of the avatar ImageButton control s OnClickListener Intent pictureIntent new Intent android provider MediaStore ACTION_IMAGE_CAPTURE startActivityForResult pictureIntent TAKE_AVATAR_CAMERA_REQUEST There is no camera available on the Android emulator Instead a mock camera screen is shown and a fixed graphic is saved whenever the user chooses to take a picture This is helpful for testing camera functionality using the Android emulator When you run the application and click the avatar ImageButton control the emu lator screen should look something like Figure 13 4 226 FIGURE 13 4 Taking a photo graph using the camera applica tion in the Android emulator HOUR 13 Working with Images and the Camera 0 CANCEL ahh When launching a remote activity that is an activity that is not necessarily part of your application you are effectively sending out an intent that says l want to do this Who can do it for me A number of other applications on the
278. hat class directly If you were paying close attention you may have noticed that you didn t use two of the onUpdate parameters appWidgetManager and appWidgetIds The ay appWidgetManager parameter isn t used because you ll be moving the code to a dif ferent method shortly where an instance of it will be retrieved separately The appWidgetIds parameter is used when you want to support multiple unique App Widgets that show different data In that case the application must track the appWidgetIds values which are assigned by the system separately and pair them correctly to the data that needs to be shown in each App Widget Typically this is done using a distinct configuration activity for each App Widget so the user controls what they want displayed in each different instance of this App Widget The App Widget should now appear in the Home screen s App Widget interface as shown in Figure 18 1 312 HOUR 18 Creating a Home Screen App Widget FIGURE 18 1 Adding the App Widget to the Home screen Choose widget Analog clock Been There Done That Music Picture frame Power Control Search Vv Try It Yourself To add an App Widget to the Home screen of an Android phone or the emulator follow these easy steps 1 2 Navigate to the Home screen Find a suitably empty area of the screen Remember that the App Widget needs 2x2 grid cells Click and hold your finger or the mouse
279. he DDMS per spective of Eclipse For example you could check out the application directory for the com androidbook triviaquiz package on the Android file system You could also step through the code of QuizSplashActivity Summary In this hour you built a basic prototype on which you can build in subsequent chapters You designed a prototype and defined its requirements in some detail Then you created a new Android project configured it and created an activity for each screen You also added custom layouts and implemented shared preferences for the application 110 HOUR 6 Designing an Application Framework Q amp A Q What class might you inherit from to provide an application with consistent shared components A By creating your own shared Activity base class you can implement behav ior that will exist within each screen Q Can an activity have its own preferences A Yes preferences can be shared among activities and an activity can have its own preferences To access shared preferences use the getSharedPreferences method To access activity level preferences use the getPreferences method Q What two things need to be configured before you can run and debug an Android application in Eclipse A You need to have configured both an AVD and the debug configuration Then you can easily launch your application straight from Eclipse for debugging and testing Workshop Quiz 1 True or False The Been There D
280. he UI thread using a Handler object on the main thread to change a TextView control called parsingStatus which displays the parsing status import android os Handler Handler mHandler new Handler LP cmb new Thread public void run Instantiate XML parser mHandler post new Runnable public void run parsingStatus setText Began Parsing XML Parsing loop here Update parsingStatus has needed mHandler post new Runnable public void run parsingStatus setText Finished parsing H start The Thread class uses the Handler object called mHandler to post information back to the main UI thread Downloading and Displaying Scores 267 Downloading and Displaying Scores Now let s work through a simple example of using AsyncTask within the QuizSettingsActivity class to handle the downloading and parsing of XML score information You begin by creating a subclass called ScoreDownloaderTask which extends the AsyncTask class within the QuizSettingsActivity class private class ScoreDownloaderTask extends AsyncTask lt Object String Boolean gt TODO Implement AsyncTask callback methods TableLayout table Because you will be populating a TableLayout control as part of this background task it makes sense to add a handy member variable within ScoreDownloaderTask as well Starting ScoreDownloaderTask After you ve implemented the ScoreDownloaderTask class
281. he battery unnecessarily Performance testing This testing uses the debugging utilities of the Android SDK to monitor memory and resource usage it also identifies performance bottlenecks as well as dangerous memory leaks and fixes them Conformance testing This testing reviews any policies license agreements and terms that an application must conform to and verifies that the applica tion complies Edge case testing An application must be robust enough to handle random and unexpected events We ve all forgotten to lock our phones on occasion only to find that the phone has received random key presses launched ran dom apps or made unnecessary phone calls from the comfort of our pocket An application must handle these types of events gracefully That is to say it shouldn t crash You can use the Exerciser Monkey tool that comes with the Android SDK to stress test an application Maximizing Test Coverage 371 Maximizing Test Coverage While 100 test coverage is unrealistic the goal is to test as much of an application as possible To do this you are likely to need to perform tests on the emulator as well as on target handsets and you might want to consider using both manual and automated testing procedures Managing the Testing Environment Don t assume that mobile applications are simpler to test just because they are smaller than desktop applications or have fewer features Testing mobile applica tions pose
282. he main menu screen Note that instead of adding new drawable resources for the options menu icons you use built in drawable resources from the Android SDK to have a common look and feel across applications You can use the built in drawable resources provided in the android R drawable class just as you would use resources you include in your application package If you want to see what each of these shared resources looks like check the Android SDK installed on your machine Specifically browse the platforms direc tory choose the appropriate target platform and check its data res drawable directory Adding an Options Menu to an Activity For an options menu to show when the user presses the Menu button on the game screen you must provide an implementation of the onCreateOptionsMenu method in the QuizGameActivity class Specifically you need to inflate load the menu resource into the options menu and set the appropriate Intent information for each menu item Here is a sample implementation of the onCreateOptionsMenu method for QUizGameActivity Override public boolean onCreateOptionsMenu Menu menu super onCreateOptionsMenu menu getMenuInflater inflate R menu gameoptions menu menu findItem R id help_menu_item setIntent new Intent this QuizHelpActivity class menu findItem R id settings_menu_item setIntent new Intent this QuizSettingsActivity class return true 139 ow 140 Did you _
283. header or footer If you have a screen with only a ListView control consider using the ListActivity class which simplifies ListView management Adding a Custom Divider A ListView divider is displayed between each ListView item The divider attribute can be either a color or a drawable graphic resource If a color is specified then a horizontal line whose thickness is configurable will be displayed between items in the list If a drawable graphic resource is used the graphic will appear between items By default no divider is displayed above the first list item nor below the last Working with the ListView Control 137 Adding a Custom Selector A ListView selector indicates which list item is currently selected within the list The ListView selector is controlled by the listSelector attribute The default selector of a ListView control is a bright orange band Try It Yourself v To add a divider to the ListView control simply open the menu xm1 layout file and change the ListView control s divider attribute to the drawable divider graphic resource a squiggly yellow line you added earlier Now add a custom selector to the ListView control To do this simply open the menu xml layout file and change the ListView control s listSelector attribute to the drawable textured graphic resource a textured orange halo you added earlier A If you make the changes to the ListView divider and selector and re launch the Be
284. his activity needs to draw stuff onscreen handle various types of user input keep score and generally follow whatever game dynamics the developer wants to sup port gt ScoresActivity This activity is about as simple as SplashActivity It does little more than load a bunch of scoring information into a TextView control within its layout gt HelpActivity tThis activity is almost identical to ScoresActivity except that instead of displaying scores it displays help text Its TextView control might possibly scroll Designing a Typical Android Application 45 Each activity class should have its own corresponding layout file stored in the appli cation resources You could use a single layout file for ScoresActivity and HelpActivity but it s not necessary If you did though you would simply create a single layout for both and set the image in the background and the text in the TextView control at runtime instead of within the layout file Figure 3 1 shows the resulting design for your game Chippy s Revenge Version 0 0 1 for Android FIGURE 3 1 Application design of a sim ple Android application j Chippy s Revenge Default Launch Activity Started aa USER LAUNCHES Menu Activity APPLICATION Help Button onClick Play Button onClick Launches Help Activity Launches Play Activity Score Button onClick Launches Scores Nes uo nys uo mu uD m0 wo nw wo mH D ao uo am u
285. his retrieves the context tied to your application Using the activity con text as shown in A works but is not recommended 4 False The Log class supports five log types error warning informational debug and verbose Workshop 57 Exercises 1 Add a logging tag to your Droid1 project Within the onCreate callback method add an informational logging message using the Log i method Run the application and view the log results 2 Implement some of the Activity callback methods in addition to onCreate such as onStart onRestart onResume onPause onStop and onDestroy Add a log message to each callback method and then run the application normally View the log results to trace the applica tion life cycle Next try some other scenarios such as pausing or suspending the application and then resuming Simulate an incoming call Watch the application log to see how the activity responds to such events This page intentionally left blank HOUR 4 Managing Application Resources What You l Learn in This Hour Using application and system resources Working with simple resource values Working with drawable resources Working with layouts Working with files Working with other types of resources v vV vV V Vv YV Android applications rely upon strings graphics and other types of resources to generate robust user interfaces Android projects can include these resources using a well defined project
286. his road unless you have a compelling reason to do so and unless you have the development testing and product team to manage it Having a poor ly localized version of an application can be worse to your image than having no localization at all Using Localization Utilities The Android SDK includes support for handling locale information For example the Locale class java util Locale encapsulates locale information Determining System Locale If you need to modify application behavior based on locale information you need to be able to access information about the Android operating system You can do this by using the getConfiguration method of the Context object as follows Configuration sysConfig getResources getConfiguration 329 Waie 330 Dw HOUR 19 Internationalizing Your Application One of the settings available in the Configuration object is the locale Locale curLocale sysConfig locale You can use this locale information to vary application behavior programmatically as needed Formatting Strings Like Dates and Times Another aspect of internationalization is displaying data in the appropriate way For example U S dates are formatted MM DD YY and December 8 1975 whereas much of the rest of the world uses the formats DD MM YY and 8 December 1975 The Android SDK includes a number of locale specific utilities For example you can use the DateFormat class android text format D
287. hly 3 Package and digitally sign the application Preparing the Release Candidate Build 385 4 Test the packaged application release thoroughly 5 Publish the application Let s explore each of these steps in more detail Preparing the Release Candidate Build It s important to polish your application and make it ready for public consumption This means you have to resolve any open or outstanding problems or issues with the application that might block the release All features must be implemented and tested All bugs must be resolved or deferred Finally you need to remove any unnecessary diagnostic code from the application and verify that the application configuration settings in the Android manifest file are appropriate for release Here s a short prerelease checklist for a typical Android application O Sufficiently test the application as described in the test plan including testing on target handsets O Fix and verify all defects and bugs in the application O Turn off all debugging diagnostics for release including any extraneous log ging that could affect application performance Preparing the Android Manifest File for Release Before release you need to make a number of changes to the application configura tion settings of the Android manifest file Some of these changes are simply com mon sense and others are imposed by marketplaces such as the Android Market You should review the Android manifest fil
288. hnology uses different terminology to describe its application compo nents The three most important classes on the Android platform are Context Activity and Intent While there are other more advanced components developers can imple ment these three components form the building blocks for each and every Android application In this hour we focus on understanding how Android applications are put together We also take a look at some handy utility classes that can help developers debug applications Designing a Typical Android Application An Android application is a collection of tasks each of which is called an activity Each activity within an application has a unique purpose and user interface To understand this more fully imagine a theoretical game application called Chippy s Revenge Designing Application Features The design of the Chippy s Revenge game is simple It has five screens gt Splash This screen acts as a startup screen with the game logo and version It might also play some music gt Menu On this screen a user can choose from among several options including playing the game viewing the scores and reading the help text 44 HOUR 3 Building Android Applications gt Play This screen is where game play actually takes place gt Scores This screen displays the highest scores for the game including high scores from other players providing players with a challenge to do better gt Help
289. hod runs in the background and is where all the real work is done gt publishProgress This method called from the doInBackground method periodically informs the UI thread about the background process progress This method sends information to the UI process gt onProgressUpdate This method runs on the UI thread whenever the doInBackground method calls publishProgress This method receives information from the background process 266 HOUR 15 Adding Network Support gt onPostExecute This method runs on the UI thread once the background processing is completed When launched with the execute method the AsyncTask class handles process ing in a background thread without blocking the UI thread Using Threads and Handlers When you want to control a thread yourself you can use the Thread class in con junction with a Handler object The style of networking that has been presented so far causes the thread it s running on to block until the operation is finished For small tasks this might be acceptable However when timeouts or additional processing time is needed such as parsing XML you need to move these time intensive operations away from the main UI thread by launching a new thread This provides a smoother experience for the user The following code demonstrates how to create and launch an anonymous thread that connects to a remote server retrieves and parses some XML and posts a response back to t
290. ial Follow these steps to use the Extract Local Variable tool 1 Select the expression getResources getColor R color title_color 2 Right click and choose Refactor Extract Local Variable or press Ctrl Alt L 3 In the dialog that appears enter a name for the variable and leave the Replace All Occurrences check box selected Then click OK and watch the magic happen 4 Repeat steps 1 3 for the text size The result should now look like this int textColor getResources getColor R color title_color float textSize getResources getDimension R dimen help_text_size TextView nameCol new TextView this nameCol setTextSize textSize nameCol setText scoreUserName nameCol setTextColor textColor table addView nameCol All repeated sections of the last five lines also have this change made How conven ient is this Now you re ready for the second tool Follow these steps to use the Extract Method tool 1 Select all five lines of the first block of code 2 Right click and choose Refactor Extract Method or choose Ctrl Alt M 3 Name the method and edit the variable names anything you want Move them up or down too if desired Then click OK and watch the magic hap pen By default the new method is below your current one If the other blocks of code are actually identical meaning the statements of the other blocks must be in the exact same order the types are all the same and so on they w
291. ication After roughly sketching the screen design you can determine exactly what Android View controls you need to implement the splash xml layout file When you are satisfied with the screen layout you can add some tweened animations to give the splash screen some pizzazz Finally you need to make sure to transition from the splash screen to the main menu screen smoothly after your animations have completed Designing the Splash Screen You ll implement the Been There Done That application from the ground up beginning with the screen users see first the splash screen Recall from Hour 6 Designing an Application Framework that you had several requirements for this screen Specifically the screen should display some information about the application title and version infor mation in a visually appealing way and then after some short period of time automati cally move on to the main menu screen Figure 7 1 provides a rough design for the splash screen 114 FIGURE 7 1 Rough design for the Been There Done That splash screen HOUR 7 Implementing an Animated Splash Screen Some Fun Logo Animation IILE VERSION INFO For the time being you will focus on designing the splash screen in portrait mode but you will try to avoid making the porting effort difficult for landscape or square orientations With the simple design of the splash screen you can be confident that the elements can scale reasonably well to
292. ication with Powerful Android Features HOUR 13 Working with Images and the Camera 217 Designing the Avatar Feature 217 Adding an Avatar to the Settings Screen Layout EE LD Working with ImageButton Controls ITE is ee siia DLL Working with Image Media 223 ix Contents Working with Bitmaps 228 Summary 230 Q amp A 230 HOUR Lae PRs Support for Location Based Services a 233 Designing the Favorite Place Feature 233 Implementing the Framework for the Favorite Place Feature 237 Using Location Based Services 240 Using Geocoding Services 246 Working with Maps 248 Summary 251 Q amp A 251 HOUR 1e Aiding Network Support mala 255 Designing Network Applications 255 Developing Network Applications 257 Accessing Network Services 260 Indicating Network Activity with Progress Bars 262 Running Tasks Asynchronously 265 Downloading and Displaying Scores 267 Downloading and Parsing Question Batches 271 Summary 274 Q amp A 274 HOUR Ae icing More Network Support na 277 Determining Data to Send to the Server 277 Accessing Phone Status Information 278 Uploading Data to a Remote Application Server 281 Summary 289 Q amp A 289 Workshop 289 X Teach Yourself Android Application Development in 24 Hours HOUR 17 Adding Social Features Enhancing Your Application with Social Features Adding Friend Support to Your Application Integrating with Social Networking Services Summary Q amp A Workshop pe HOUR 18 Creating a Home Screen App Widge
293. ickname String strNickname nicknameText getText toString After you have extracted the String value from the EditText input field you can save it to SharedPreferences Editor using the putString method Editor editor mGameSettings edit editor putString GAME_PREFERENCES_NICKNAME strNickname editor commit The Nickname Email and Password settings can be saved as String values but the Date of Birth and Gender settings are of long and integer types respectively To save these settings you must extract the value from the appropriate control convert it if necessary and save it using the SharedPreferences Editor methods putLong and putInt For now you can commit the input from the Nickname Email and Gender fields You will work further with the Date of Birth and Password fields in the next hour when you implement the DatePickerDialog and Password Dialog window If you go back through the QuizSettingsActivity class and look for the places where you have TODO comments you can see exactly where you need to commit the data Saving Form Data with SharedPreferences 177 Reading Settings from SharedPreferences When you begin saving settings in a persistent fashion you are going to need to be able to read them back out and load them into the form for editing To do this you need to access the game preferences and check whether specific settings exist For example you might want to check and see if the Nickname se
294. idden keyssoft navexposed navhidden ISO 639 1 two letter language codes ISO 3166 1 alpha 2 region code in ALL UPPERCASE preceded by a lowercase r Screen size and density ratio Portrait mode landscape mode Screen density that the resource is for No Touch screen Stylus only Finger Touch screen Keyboard available Keyboard not available to user resources used only with software keyboard Whether navigational keys are available or hidden because phone keypad is shut Configuration Management for Android 335 Directory Qualifier Type Values Comments Primary non touch screen nonav dpad Four key directional pad navigation method trackball wheel trackball scroll wheel SDK version v1 v2 v3 v4 The SDK version s API v5 v6 v7 level for example v1 is and so on Android SDK 1 0 while v7 represents Android SDK 2 1 You can concatenate together resource directories by using dashes Here are some good examples of properly qualified directories res values en rUS port finger res drawables en rUS land res values en qwerty The following are some incorrectly qualified directories res values en rUS rGB res values en rUS port FINGER res values en rUS port finger custom For an exhaustive list of the qualifiers available for resource customization mobile country code carrier screen size and so on see the Android developer website http developer android com guide topics resources resour
295. ide protected void onPreExecute mProgressCounter QuizScoresActivity this setProgressBarIndeterminateVisibility true There are two tabs of scores Each tab s scores are downloaded separately and you want the progress indicator to display until both are complete Thus you can create a counter mProgressCounter to track each download In this way you could also add a third tab and the indicator would still hide at the correct time In the onCreate method of the activity the following line must be added before the indeterminate progress bar indicator will display properly in the title bar requestWindowFeature Window FEATURE_INDETERMINATE_PROGRESS You must call this method before you call the setContentView method Handling the Background Processing Now it is time to identify what processing should run asynchronously For this example it is the downloading and parsing code You override the doInBackground method which is where all the background processing takes place The methods called within doInBackground will not block the main UI thread Here s a sample implementation of the doInBackground method with exception handling removed for clarity Override protected Boolean doInBackground Object params boolean result false String pathToScores String params Q table TableLayout params 1 Xm1PullParser scores null URL xmlUrl new URL pathToScores scores Xm1PullParserFactory n
296. ile development project can benefit from a good development process with a solid test plan The following are some quality measures that can greatly improve the development process gt Coding standards and guidelines gt Regular versioned builds gt A defect tracking system with a process for resolving defects gt Systematic application testing using a test plan You can outsource application testing to a third party Keep in mind that the suc cess of any outsourced project depends heavily on the quality of the documenta tion you provide for example functional specifications use cases to the out sourcing facility Developing Coding Standards When developers have and follow some guidelines their code is more cohesive and easy to maintain Developing a set of well communicated coding standards for development can help drive home some of the important requirements of mobile applications For example developers might want to do the following gt Discuss and come up with a common way for all developers to implement error and exception handling gt Move lengthy or process intensive operations off the main UI thread gt Release objects and resources that aren t actively being used gt Practice prudent memory management and track down memory leaks gt Use resources appropriately For example don t hard code data in code or layout files Performing Regular Versioned Builds Implementing a reproducible build
297. ill also be replaced with calls to this new method You can see this in the count of additional occurrences shown in the dialog for the Extract Method tool If that count doesn t match what you expect check that the code follows exactly the same pattern 420 APPENDIX B Eclipse IDE Tips and Tricks Now you have code that looks like the following addTextToRowithValues newRow scoreUserName textColor textSize It is easier to work with this code than with the original code and it was created with almost no typing If you had ten instances before refactoring you ve saved a lot of time by using a useful Eclipse tool Resolving Mysterious Build Errors Occasionally you might find that Eclipse is finding build errors where there were none just moments before In such a situation you can try a couple quick Eclipse tricks First try refreshing the project Simply right click the project and choose Refresh or press F5 If this doesn t work try deleting the R java file which is found under the gen directory under the name of the particular package being compiled Don t worry This file is created during every compile If the Compile Automatically option is enabled the file is recreated Otherwise you need to compile the project again Finally you can try cleaning the project To do this choose Project Clean and choose the projects you want to clean Eclipse removes all temporary files and then rebuilds the project s
298. imple XML file and extract the mock score data Retrieving XML Resources First you need to access the mock XML data you saved in the project resources Specifically you want to parse the res xml allscores xml file You can initialize an instance of an Xm1lResourceParser by using the getXML method as follows XmlResourceParser mockAllScores getResources getXm1 R xml allscores Parsing XML Files with XmlResourceParser The mock score files have a very simple schema with only two tags lt scores gt and lt score gt You want to find each lt score gt tag and extract its username rank and score attributes Because you can assume a small amount of data you can imple ment your parsing routing by using a simple while loop to iterate through the events by using the next method as follows int eventType 1 boolean bFoundScores false Find Score records from XML while eventType XmlResourceParser END DOCUMENT if eventType XmlResourceParser START_TAG Get the name of the tag eg scores or score String strName scores getName if strName equals score bFoundScores true String scoreValue scores getAttributeValue null score String scoreRank scores getAttributeValue null rank String scoreUserName scores getAttributeValue null username insertScoreRow scoreTable scoreValue scoreRank scoreUserName Working with XML 157 eventType scores next
299. in many countries and many locales Developers need to keep this in mind when designing and developing applications for the Android platform applications will likely be used by foreign speaking users In this hour you learn about the localization features of the Android platform and the Android Market In Hour 24 Publishing on the Android Market you ll learn how your application can be made available for distribution within the Android Market General Internationalization Principles With a global marketplace developers can maximize profits and grow their user base by supporting a variety of different languages and locales Let s take a moment to clarify some terms While you likely know what we mean by language you may not be aware that each language may have a number of different locales For example the Spanish spoken in Spain is quite different from that spoken in the Americas the French spoken in Canada differs from that of Europe and Africa and the English spoken in the United States differs from that spoken in Britain English is a language while English United States English United Kingdom and English Australia are locales see Figure 19 1 322 FIGURE 19 1 People who speak the same language often have localized dialects Oat HOUR 19 Internationalizing Your Application l Australian British American Applications are made up of data and functions behavior For most applications the beh
300. in the RelativeLayout control add an ImageView control Set the ImageView control s layout_alignParentLeft and layout_alignParentTop attributes to true Set the image s src attribute to the drawable quizicon graphic Still within the RelativeLayout control add a TextView control for the title text Set the TextView control s text textSize and textColor attributes to the resources you just created Then set the layout_centerHorizontal and layout_alignParentTop attributes to true You can make TextView text glow by setting the shadow attributes including shadowColor shadowDx shadowDy and shadowRadius 5 Finish the RelativeLayout control by adding one more ImageView control Set the control s layout_alignParentRight and layout_alignParentTop attributes to true Set the image s src attribute to the drawable quizicon graphic Next we must add a second RelativeLayout to hold the ListView and ImageView controls Start by adding a new RelativeLayout outside of the one we were just working in but still inside the LinearLayout Now add the last ImageView control inside this new RelativeLayout Set its src attribute to the drawable half graphic its layout_width attribute to fill_parent and its layout_height attribute to fill_parent to ensure that the control fills any space at the bottom of the screen Additionally set its layout_alignParentBottom attribute to true and scaleType attribute to fitEnd so
301. in the layout preview Click the Properties tab This tab displays all the properties and attributes that can be configured for the TextView control you selected Scroll down to the property called Text and note that it has been set to a string resource variable called string hello Click the Text property called string hello on Properties tab You can now modify the field Each time you change this field note how the layout preview changes You can type in a string directly type a different string resource string app_name for example or click the little button with the three dots and choose an appropriate resource from the list of string resources available to your application Switch to the main xml tab and note the XML If you save and run your proj ect in the emulator you should see results similar to those displayed in the preview Working with Files Feel free to continue to explore You might want to try adding controls such as an ImageView control or another TextView control to your layout We cover designing layouts in much more detail later in this book Using Layout Resources Programmatically If and when you need to access an entire layout programmatically you can use a LayoutInflater class to inflate the layout file into a View object as in the follow ing example LayoutInflater inflater getLayoutInflater View layout inflater inflate R layout main null However in most instances you do not
302. ined as the default launch activity in the Android manifest file gt gen com androidbook droid1 R java A generated resource management source file Do not edit this file gt assets folder Required folder where uncompiled file resources can be includ ed in the project gt res folder Required folder where all application resources are managed Application resources include animations drawable graphics layout files data like strings and numbers and raw files Familiarizing Yourself with Eclipse gt res drawable Application icon graphic resources are included in several dif ferent sizes gt res layout main xml Layout file used by DroidActivity to draw onscreen gt res values strings xml The path where string resources are defined You can also add existing Android projects to Eclipse by using the Android Project Wizard To do this simply select Create Project from Existing Source instead of the default Create New Project in Workspace in the New Android Project dialog refer to Figure 1 2 Several sample projects are provided in the samples direc tory of the Android SDK under the specific platform they support For example the Android SDK sample projects are found in the directory platforms android xxx samples where xxx is the platform version number You can also select a third option Create Project from Existing Sample which will do as it says However make sure you choose the build target f
303. inflate them pro grammatically at runtime You can create new types of controls or you can simply extend the functionality of existing controls such as TextView or Button controls For more information on implementing custom View controls see http developer android com guide topics ui custom components html Working with Input Methods The Android platform provides a user friendly software keyboard see Figure 21 2 for devices that do not have hardware keyboards The Android SDK also includes powerful text input method support for predictive text and downloadable input method editors IMEs Designing Advanced User Interfaces 351 FIGURE 21 2 The Android software key board BME 1 44PM Seca Bil Aes bunny Show All Pets g1 wi ped fri pti by fai fi dt PS4 101 fig hj ik pi amp zxcv bnm amp 7123 A gaj Handling User Gestures You already know how to listen for click events You can also handle gestures such as flings scrolls and taps by using the GestureDetector class android view GestureDetector You can use the GestureDetector class by implementing the onTouchEvent method within an activity The following are some of the gestures an application can watch for and handle gt gt onDown Occurs when the user first presses the touch screen onShowPress Occurs after the user first presses the touch screen but before the user lifts up or moves around on the screen onSingleTapUp Occur
304. ing Dimension and Color resources you need for the screen layout so let s talk for a moment about the mock question batches Eventually the questions used by the Been There Done That application will be retrieved from a server on the Internet However for now you can create two batch es of mock questions that can be accessed locally as XML res xm1 sampleques tions xml and res xm1 samplequestions2 xml Later when you add network support to the application you will retrieve this same XML from a server By includ ing mock batches of questions now you can iron out the game logic without worry ing about network connectivity Regardless of whether the batch of questions is sourced locally or from a remote server the XML block looks the same Here is what it looks like lt xml version 1 0 encoding utf 8 gt lt This is a mock question XML chunk gt lt questions gt lt question number 7 text Have you ever been on an African safari imageUr1l http www perlgurl org Android BeenThereDoneThat Questions q1 png gt lt question number 2 text Have you ever climbed a mountain imageUrl http ww perlgurl org Android BeenThereDoneThat Questions q2 png gt lt question number 3 text Have you ever milked a cow imageUrl http ww perlgurl org Android BeenThereDoneThat Questions q3 png gt lt questions gt As you can see the XML is very simple It has one
305. ing 413 choose Window Preferences or Eclipse Preferences in Mac OS X Select the Android preferences and set the path to where you installed the Android SDK Once you have set the path appropriately you will see a number of target SDK versions Android 1 0 1 5 1 6 2 0 2 01 2 1 and so on listed below SDK Location in the Android Preferences dialog in Eclipse Upgrading the Android SDK The Android SDK is currently in development which means you will inevitably have to upgrade the version of the SDK on your machine Changes to the Android SDK may include addition update and removal of features package name changes and tool updates With each new version of the SDK Google provides the following useful documents gt An Overview of Changes A brief description of major changes to the SDK gt An API Diff Report A complete list of specific changes to the SDK gt Release Notes A list of known issues with the SDK To update the Android SDK you launch the Android SDK and AVD Manager by clicking the little icon that looks like a phone or under Window Android SDK and AVD Manager and update all packages and check for new ones Upgrading the Android SDK involves updating the Android targets and AVD within Eclipse updating path variables and reconfiguring existing Android development tools as needed After you upgrade the development environment you need to port your Android applications to the new SDK Configuring Devel
306. ing it up by pressing Ctrl space bar Auto complete not only saves time in typing but can be used to jog your memory about methods or find a new method You can scroll through all the methods of a class and even see the associated Javadocs with them You can easily find static methods by using the class name or the instance variable name You follow this name with a dot and maybe Ctrl spacebar and then scroll through all the names Then you can start typing the first part of a name to filter the results Editing Code Efficiently Sometimes you might find that the editor window is just too small especially with all the extra little metadata windows and tabs surrounding it Try this Double click Renaming Almost Anything 417 the tab of the source file that you want to edit Boom It s now nearly the full Eclipse window size Just double click to return it to normal Ever wish you could see two source files at once Well you can Simply grab the tab for a source file and either drag it over to the edge of the editor area or to the bot tom You then see a dark outline showing where the file will be docked either side by side with another file or above or below another file This creates a parallel editor area where other file tabs can be dragged as well Ever wish you could see two places at once in the same source file You can Right click the tab for the file in question and choose New Editor A second editor tab for the same
307. ing mobile users than English speaking ones but generally English market users are willing to pay much higher prices for applications The answer really boils down to knowing your user audience s which should be part of your business plan to begin with Q Why does my Android handset show only a subset of the languages and locales listed in this hour A While the Android platform supports a variety of languages and locales mobile handset manufacturers and operators can customize the locale support available on specific devices This may be done for resource efficiency For example a phone available through a U S operator might support only English American and Spanish Americas Q What language should I use for default resources such as strings A Your default resources should be in the language locale used by your largest target audience the most generic likely values that will appeal to the most users If you re targeting the world at large the choice is often English but it need not be For example if your application allows turn based directions anywhere in China then you d probably want your default language locale to be one of the Chinese options and even within China different locale set tings are more widely used than others unless you were targeting business types who are visiting China in which case you re back to using English which is still the international language of business at least for now
308. ingtones and wallpapers that support the brand Setting the Ringtone An application can change the handset ringtone by using the RingtoneManager To modify the ringtone an application must have the appropriate permission android permission WRITE_SETTINGS registered in the Android manifest file You can also launch the ringtone picker by using the ACTION_RINGTONE_PICKER intent Setting the Wallpaper An application can set a wallpaper for the background of the Home screen by using the WallpaperManager class Various methods are provided to retrieve the current wallpaper and set a new one using a bitmap a resource or another form of wallpaper Personalizing Android Devices 357 In addition to using static images as wallpapers Android supports the notion of live wallpapers These are essentially animated wallpapers but can contain almost any thing an application can draw on a surface For example you could create a wall paper that visually shows the current weather time of day information about music playing a slideshow or some sort of video or animated demonstration Live wallpa pers are similar to widgets in that they are surfaces however the implementation details are different For more information on wallpapers see the Android SDK documentation related to the android service wallpaper package Creating a Live Wallpaper In addition to still image wallpapers Android supports the notion of a live wallpa per Instead of
309. initialLayout layout widget gt lt appwidget provider gt This definition file defines an App Widget that will update every three hours and be 2x2 grid cells in size If you ve done the math you may have noticed that the 146dp on each edge is not double the 74dp we previously defined a grid cell size to be Although a grid cell is typically considered 74dp on edge when calculating the size you must subtract 2dp from the final result In this example we multiplied 74 by 2 to get 148 Then we subtracted 2 from it to get to the 146 we put in the file Without this the App Widget may not draw in the expected number of cells This App Widget will receive update calls every 10 800 000 milliseconds which cor responds to three hours In addition this App Widget will initially use a predefined layout referenced by android initialLayout layout widget The contents of this layout file will be discussed shortly Updating the Android Manifest File The Android manifest file needs to be updated to tell the system where to find the definition of the App Widget An App Widget is a specialized form of a BroadcastReceiver control Therefore a lt receiver gt definition must be placed within the AndroidManifest xml file that defines what Intent objects will be received and a couple other pieces of data specific to the App Widget To accomplish this task add the following lt receiver gt section to the application sec tion of the And
310. inition even the lightweight friend support you added to the Been There Done That applica tion is sharing private data the user s nickname score and avatar See the exercises for accessing friends avatar images from the server Technically if you published this application you would want to make it very very clear to the player that this information is going to be uploaded to the application server and accessible to other players Workshop 303 Q How do find out if my application can integrate with a social network application that s not listed in this hour A Whether you want to integrate with a social networking service or some other web service for example Google Amazon eBay the simplest way to find out if a service has an API is to browse the company s website There you will often find a link for developers near the information about customer support contact and company information or within the customer support FAQ Most companies require developers to agree to terms of use and some companies require you to register for a special API key to use the services Workshop Quiz 1 True or False All Android applications can and should be enhanced using social features 2 How does the Been There Done That application create friend relationships A By allowing the player to search the application server for friends he or she recognizes B By allowing the player to input a friend s email address C
311. ion to the manifest file using the manifest file editor Observe the changes made by looking at the XML Attempt to do the same by just editing the XML This page intentionally left blank HOUR 6 Designing an Application Framework What You l Learn in This Hour gt Designing an Android trivia game gt Implementing an application prototype gt Running the game prototype It s time to put the skills you have learned so far to use In this hour you design an Android application prototype a basic framework on which you will build in the future You will add many exciting features to this application over the course of this book Designing an Android Trivia Game Because social trivia games are so popular right now you want to implement one In your soon to be viral game the user will be asked random questions about travel and related experiences such as these gt Have you ever visited the pyramids in Egypt gt Have you ever milked a cow gt Have you ever gone diving with great white sharks gt Have you climbed a mountain The user with the highest score is the most well traveled and well seasoned You ll call the game Been There Done That 96 HOUR 6 Designing an Application Framework Determining High Level Game Features Try to imagine what features a good game application should have In addition to the game question screen itself you need the following gt A startup screen gt A way to view
312. ional state transfer REST 300 requestLocationUpdates method 245 451 resources requestRouteToHost method 261 res folder 12 15 16 62 res drawable 13 res layout help xml 144 res layout main xml 13 res layout scores xml 150 res raw quizhelp txt 145 res values strings xml 13 resource directory qualifiers 334 335 resources adding to game screens 200 202 to help screens 145 146 to main menu screens 131 to options menus 138 139 to scores screens 151 152 to settings screens 165 166 to splash screens 116 117 Android Mobile Application Development website 424 425 application resources 46 definition of 59 referencing 62 storing 60 62 colors explained 64 65 retrieving 65 supported color formats 65 index more useful Email us at indexes samspublishing com 452 resources compared to project assets 74 dimensions explained 65 66 supported dimension units 66 drawable resources 104 editing AndroidManifest xml file 13 15 res files 15 16 string resources 16 explained 73 files See files images loading 67 ShapeDrawable class 67 supported image formats 66 67 InformIT website 423 424 layouts accessing programmatically 71 adding to Been There Done That game 104 designing with Layout Resource Editor 68 70 designing with XML 69 explained 67 68 online Android resources 425 426 raw resource files 72 73
313. irst option to get the list of sample projects you can create Editing Project Resources By default the Android manifest file resource editor is opened when you create a new Android project If you have clicked away from this screen to check out the var ious project files simply double click the AndroidManifest xml file within your new project to return to the Android manifest file resource editor see Figure 1 3 6 GKF O G EBC BEF GAA pos 3 Package Exp 1 Droid Bue comandroidbook dro DroisActivityjeve Package comandroidbookdroid Defines general information about the AndroidManitestimm Version code 1 Vernon name 19 Shared userid gt drawable hdpi Shared uter label seoapng gt drawable idpi DOO Attributes for Uses sak iconpng The userad tag describes the SDK gt drawable mdpi a features that the comaining package 1 iconpng on pa ra ayou omet x mainami Min SOK version 7 Browse values zaa stringsxmi 1i AndroidManitestam hr amen x I5 gefaun propenies Target SDK version To export the application for distndution you have the fosowing optons Use the Export Wizard to export and sign an APK Export an unsigned APK and sign it manuatty Manifest Application Permissions Instrumentation AndroxiManifestam Z Problems Javadoc E Declaration Console Outline Launching TrviaQuiz17 13 Ditow FIGURE 1 3 Editing an Android res
314. is built on a Linux kernel and leverages its built in system security as part of the Android security model Each Android application exists in its own virtual machine and operates within its own Linux user account see Figure 5 6 Applications that want access to shared or privileged resources on the handset must declare those specific permissions in the Android manifest file This security mecha nism ensures that no application can change its behavior on the fly or perform any operations without the user s permission Because each application runs under a different user account each application has its own private files and directories just as a Linux user would Android applications can access their own private files and databases without any special permissions However if an application needs to access shared or sensitive resources it must declare those permissions using the lt uses permission gt tag with in the Android manifest file These permissions are managed on the Permissions tab of the Android manifest file resource editor Managing Application Permissions 89 ANDROID PLATFORM SECURITY MODEL esti Android platform Fi ET z EE architecture Android Application 1 Android Application 2 from a security DroidWars Chippy s Revenge erspective com androidbook DroidWars com androidbook Chipmunk pee Linux User Linux User com androidbook DroidWars com androidbook Chipmunk LS ss Priv
315. is essential when publishing and supporting applications The lt manifest gt tag android versionName attribute is a string value provided to keep track of the application build number For example the Droid1 project has the version name 1 0 The format of the version name field is up to the developer However note that this field is visible to the user Setting the Version Code The version code allows the Android platform to programmatically upgrade and downgrade an application The lt manifest gt tag android versionCode attribute is Configuring Basic Application Settings 83 an integer value that the Android platform and Android marketplaces use to man age application upgrades and downgrades android versionCode generally starts at a value of 1 This value should be incremented with each new version of the application deployed to users The version code field is not visible to the user and need not stay in sync with the version name The version code needs to be incremented for published applications or testing By the purposes only not each time you deploy an application onto a device for ay debugging Setting the Minimum Android SDK Version Android applications can be compiled for compatibility with several different SDK versions You use the lt uses sdk gt tag to specify the minimum SDK required on the handset in order for the application to build and run properly The android minSdkVersion attribute of this ta
316. is trying to load the main xml layout file which no longer exists You need to modify each class to load the specific layout associated with the activity For example in the QuizHelpActivity class you modify the setContentView method to load the layout file you created for the help screen as follows setContentView R layout help You make similar changes to the other activity files such that each call to setContentView loads the corresponding layout file Updating the Android Manifest File You now need to make some changes to the Android manifest file First you modify the application icon resource to point at the drawable quizicon icon you created Second you need to register all your new activities in the manifest file so they will run properly Finally you set the Debuggable application attribute to true and veri fy that you have QuizSplashActivity set as the default activity to launch 106 Way Dw HOUR 6 Designing an Application Framework For the book code we ve only created a single icon However even if you ve creat ed three differently sized icons and placed them in the three default directories drawable ldpi drawable mpi and drawable hdpi only a single reference to the icon is required Just make sure all of the icons are named exactly the same This allows the Android system to choose the most appropriate one for the hardware the application is running on Creating Application Pre
317. istinct performance issues Always test operations such as animations on a handset to be sure your implementa tion is feasible Q Why did you iterate through each child view of the TableLayout control instead of accessing each TableRow control R id TableRow01 and R id TableRow02 by name A It would be perfectly acceptable to access each TableRow element by name if each one is guaranteed to exist in all cases You will be able to take advantage of this iterative approach later when you port your project to different screen orientations For now the Splash screen draws well only in portrait mode Q What would happen if you applied LayoutAnimationController to TableLayout instead of each TableRow A If you applied LayoutAnimationController to TableLayout each TableRow control instead of each ImageView control would spin into existence It would be a different less visually appealing effect Workshop Quiz 1 True or False There is no way to stop an animation once it has started 2 What types of operations are supported with tweened animation A Transparency motion and 3D rotation B Alpha scale rotate and translate C Dance sing and be merry 3 True or False LinearLayout can be used to allow all child View objects to draw above and below each other vertical Workshop 125 4 Which of these is not a built in layout in the Android SDK A FrameLayout B CircleLayout C HorizontalLayout D RelativeLayo
318. it supports the language locale you chose 2 Change the Been There Done That application so that it loads a custom drawable or color resource for a specific language or locale For example change the planet graphic on the main menu to something more specific to that language locale Test the results in the Android emulator and on a real handset if it supports the language locale you chose HOUR 20 Developing for Different Devices What You l Learn in This Hour gt Designing for different handset configurations gt Handling screen orientation changes gt Working with different Android SDK versions The Android platform is maturing at an accelerating rate We re seeing revisions of the Android SDK rolling out every few months with new handsets showing up all the time In this hour you learn how to develop Android applications for different targets Android devices vary in terms of hardware and software features as well as the version of the Android SDK they run Configuration Management for Android Developers must try to support the widest possible range of devices without biting off more than they can chew in terms of maintenance and configuration management The following are some factors to consider when determining target platforms gt What hardware features will the application require Does the application require a touch screen A hardware keyboard A directional pad Specific screen dimensions gt
319. ity that is not in the foreground is subject to shutdown In other words an Android application must keep state and be ready to be interrupted and even shut down at any time Using Activity Callbacks The Activity class has a number of callbacks that provide an opportunity for an activity to respond to events such as suspending and resuming Table 3 1 lists the most important callback methods TABLE 3 1 Key Callback Methods of Android Activities Callback Method Description Recommendations onCreate onResume onPause onDestroy Called when an activity starts or restarts Called when an activity becomes the foreground activity Called when an activity leaves the foreground Called when an application is shutting down Initializes static activity data Binds to data or resources required Sets layout with setContentView Acquires exclusive resources Starts any audio video or animations Saves uncommitted data Deactivates or releases exclu sive resources Stops any audio video or ani mations Cleans up any static activity data Releases any resources acquired 50 FIGURE 3 2 Important call back methods of the activity life cycle HOUR 3 Building Android Applications The main thread is often called the UI thread because this is where the processing for drawing the UI takes place internally An activity must perform any processing that takes place during a call
320. ively straightforward as form controls go Generally speaking a Button control is simply a clickable area with a text string label Figure 10 5 shows a Button control Configuring Button Controls Many of the typical attributes of TextView controls such as textColor and textSize are available for the Button text label You need two simple Button con trols for the settings screen one for launching the Password Dialog window and one for launching the DatePickerDialog You configure these Button controls by giving each a unique identifier and setting the text attribute labels of each You also set each Button control s layout_width and layout_height attributes to wrap_con tent so that each button scales appropriately based on the text label The Android platform actually supports two kinds of Button controls the basic Button control and the ImageButton control An ImageButton control behaves much like a regular Button control only instead of displaying a text label it dis plays a Drawable image resource You can use attributes to modify the look of a Button control For example you can change the shape of the button by default a white rectangle with rounded corners by setting the background drawableTop drawableBottom drawableLeft and drawableRight attributes of the Button to a Drawable resources Using Common Form Controls 171 Try It Yourself v Try changing the look of the Button control called Button_DOB by ta
321. ivity 3 Update the activity s onCreateDialog method to build and return the appropriate custom AlertDialog 4 Launch the dialog using the showDialog method 187 FIGURE 11 2 DatePicker Dialog used for date of birth input Dw 188 FIGURE 11 3 A custom dialog used for han dling password input HOUR 11 Using Dialogs to Collect User Input Adding a Custom Dialog to the Settings Screen In the Been There Done That application you want to include a custom dialog to handle entering and verifying a new password Figure 11 3 shows the password dia log states matching and not matching passwords Set Password Set Password Password a Password again The custom password dialog you want to create requires two text input fields for entering password data When the two passwords match the password will be set Figure 11 4 shows a rough design of the settings screen in this case Working with Custom Dialogs PASSWORD Text Hidden as Typed PASSWORD Again Text Hidden as Typed Passwords Match The password dialog is simply a subform of the settings screen that has two EditText input fields You also need a TextView control below the input fields to tell the user whether the passwords match Figure 11 5 shows the layout design of the password dialog LinearLayout Vertical Orientation TextView Password EditText Password 1 Input TextView Passwor
322. k View v showDialog FRIEND_EMAIL_DIALOG_ID 3 You need to update the onCreateDialog method of the QuizSettingsActivity class to include a case statement for this new dialog case FRIEND_EMAIL_DIALOG_ID final View friendDialogLayout layoutInflater inflate R layout friend_entry ViewGroup findViewById R id root AlertDialog Builder friendDialogBuilder new AlertDialog Builder this friendDialogBuilder setView friendDialogLayout final TextView emailText TextView friendDialogLayout findViewById R id EditText_Friend_Email friendDialogBuilder setPositiveButton android R string ok new DialogInterface OnClickListener public void onClick DialogInterface dialog int which String friendEmail emailText getText toString if friendEmail null amp amp friendEmail length gt 0 doFriendRequest friendEmail return friendDialogBuilder create This dialog implementation should look quite familiar Again you are building up an AlertDialog control by inflating a layout resource When the user clicks the OK button in the dialog see Figure 17 3 the email address is communicated to the application server asynchronously using the FriendRequestTask class We ll talk more about this in a moment The application server is responsible for setting up the friend relationship if the friend s email address exists in the datastore Adding Friend Support to Your Application
323. kberry Palm Pre BREW and J2ME With more than two decades of experience in professional soft ware production Lauren is a recognized authority in enterprise architecture and the devel opment of commercial grade mobile applications Lauren received a B S in Computer Science from the University of California Santa Cruz She spends her copious free time traveling the world with her geeky mobile minded hus band and is an avid nature photographer Her work has been published in books and news papers around the world In South Africa she dove with 4 meter long great white sharks and got stuck between a herd of rampaging hippopotami and an irritated bull elephant She s been attacked by monkeys in Japan gotten stuck in a ravine with two hungry lions in Kenya gotten thirsty in Egypt narrowly avoided a coup d tat in Thailand geocached her way through the Swiss Alps drank her way through the beer halls of Germany slept in the crumbling castles of Europe and gotten her tongue stuck to an iceberg in Iceland while being watched by a herd of suspicious wild reindeer Shane Conder has extensive development experience and has focused his attention on mobile and embedded development for the past decade He has designed and developed many commercial applications for BREW J2ME Palm Windows Mobile and Android some of which have been installed on millions of phones worldwide Shane has written extensively about the mobile industry and evaluate
324. king the follow ing steps in the settings xm1l layout file 1 Change the background property of the Button control to the Drawable graphic resource called drawable textured 2 Change the drawableTop property of the Button control to the Drawable graphic resource called drawable divider 3 Change the drawableBottom property of the Button control to the Drawable graphic resource called drawable divider Note that the Button control is now an ugly orange menace on the screen You ve created a monster 4 Change the Button control back to the default Button control look and feel by removing the background drawableTop and drawableBottom properties from Button_DOB A Handling Button Clicks Handling the click event of a Button control is achieved by using the setOnClickListener method Specifically you need to implement the onClick method of View OnClickListener This is where any event handling for clicks should take place For example to handle when a user clicks the Button control called Button_DOB you add the following code to the onCreate method of the QuizSettingsActivity class to handle the event Button pickDate Button findViewById R id Button_DOB pickDate setOnClickListener new View OnClickListener public void onClick View v Handle date picking dialog You retrieve the Button control by using the findViewById method and then you set View OnClickListener for the control by using th
325. l add some light social integra tion to allow players to follow other players game scores This is a relatively simple Adding Friend Support to Your Application way to encourage game play By sharing only public score information you can avoid having to build in support for friend validation and confirmation The simple social feature you will add in this hour works as follows 1 A player adds a friend s email address to mark the person as a friend 2 If the email address matches that of another player on the application server a friendship link is established 3 The players now see each other s scores on the Scores of Friends tab of the scores screen The full implementation of the code provided in this hour is available at this book s website http www informit com title 9 780321673350 Enabling Friend Requests on the Settings Screen To add friend support to the Been There Done That application you need to update QuizSettingsActivity to allow the user to input friend email addresses Specifically you need to do the following gt Add a button to the settings screen to launch a new dialog gt Implement the dialog to QUizSettingsActivity to allow the user to input a friend s email address gt Add some networking code to communicate the friend request to the applica tion server Updating the Settings Screen Layout You need to update the user interface of the Been There Done That
326. l areas gt Task management File management Emulator interaction Logging Screen captures 30 Ditow FIGURE 2 3 Using DDMS to examine thread activity for the Droid1 applica tion HOUR 2 Mastering the Android Development Tools DDMS and the DDMS perspective are essential debugging tools Now let s take a look at how to use these features in a bit more detail The DDMS tool can be launched separately from Eclipse You can find it in the Android SDK tools directory Managing Tasks The top left corner of the DDMS lists the emulators and handsets currently connect ed You can select individual instances and inspect processes and threads You can inspect threads by clicking on the device process you are interested in for example com androidbook droid1 and clicking the Update Threads button Sp as shown in Figure 2 3 You can also prompt garbage collection on a process and then view the heap updates by clicking the green cylinder button 8 Finally you can stop a process by clicking the button that resembles a stop sign 8 6 SJU Qv osr trir s tacS2z cu lt VansiaAVD 21 debug m0 ae Orre 2 n 0 uo us wo iu 189 aw 20 Orre Retest Tue Age 13 125026 EDT 2019 Om jova iang Otyect maang Object BERLE CEEEUESEE RE gg Debugging from the DDMS Perspective Within the DDMS perspective you can choose a specific process on an emulator or a hands
327. l so that the RelativeLayout ListView and ImageView controls are shown in a top down fashion Figure 8 2 shows the layout design of the main menu screen LinearLayout Vertical Orientation RelativeLayout aa ListView TextView Play Game TextView View Scores TextView Settings TextView Help ee Implementing the Main Menu Screen Layout 131 Implementing the Main Menu Screen Layout To implement the main menu screen you begin by adding new resources to the project Then you must update the menu xml layout resource to reflect the main menu screen design Adding New Project Resources Now that you have your layout designed you need to create the drawable string color and dimension resources you will use in the layouts used by the main menu screen You begin by adding four new graphic resources to the res drawable directory bkgrnd jpg divider png half png and textured png LinearLayout will use the bkgrnd jpg graphic file as the background image The ListView control will use the divider png and textured png graphics for the custom divider and selec tor respectively The ImageView control will use the half png graphic at the bottom of the screen You continue by adding and modifying several new strings in the res values strings xml resource file so that you have a string for each menu option as well as one for the title TextView control Finally update the color re
328. l to building trust relationships between developers and users It is very important to secure private key informa tion The private key can be used to digitally sign the release package files of your Android application as well as any upgrades This ensures that the application as a complete entity is coming from you the developer You don t need to use a certificate authority such as Verisign Equifax or any of the other companies that will certify that you are who you say you are before pro viding a certificate Self signing is standard for Android applications which simply means that you aren t proving who you are but the next time you publish some thing if the keys match then users and Android will know it s been signed by the same person or entity So don t share your private key Application updates must be signed with the same private key For security reasons the Android package manager does not install the update over the existing applica tion if the key is different This means you need to keep the key corresponding with the application in a secure easy to find location for future use The Android platform tests the digital signature only at install time Therefore if the signature expires after installation the application will continue to run Exporting and Signing the Package File You are now ready to export and sign your Android package file To do this using the wizard provided
329. language or regional locale If no resource matches the required locale the system falls back on the default resource How Android Localization Works 325 Developers can specify specific language and locale resources by providing resources in specially named resource directories of the project Any application resource can be localized whether it is a string resource file a drawable an animation sequence or some other type Specifying Default Resources So far every resource in the Been There Done That application is a default resource A default resource is simply a resource that does not have specific tags for loading under different circumstances Default resources are the most important resources because they are the fallback for any situation when a specific tailored resource does not exist which happens more often than not In the case of the Been There Done That application the default resources are all in English Specifying Language Specific Resources To specify strings for a specific language you must supply the resource under a spe cially named directory that includes the two letter language code provided in ISO 639 1 see www loc gov standards iso639 2 php code_list php For example English is en French is fr and German is de Let s look at an example of how this works Say that you want the Been There Done That application to support English German and French strings You would take the following s
330. languages chosen by a handset manufacturer or operator How Android Localization Works 323 gt The countries languages and locales supported by the Android Market appli cation the countries and locales where Google can sell legally this list grows continuously The specific locales supported by Android as of this writing are shown in Table 19 1 TABLE 19 1 Languages and Regions Supported in Android Language Regions Chinese zh Czech cs Dutch nl English en French fr German de Italian it Japanese jp Korean ko Polish pl Russian ru Spanish es PRC zh_CN Taiwan zh_TW Czech cs_CZ Netherlands nl_NL Belgium nl_BE United States en_US Britain en_GB Canada en_CA Australia en_AU New Zealand en_NZ Singapore en_SG France fr_FR Belgium fr_BE Canada fr_CA Switzerland fr_CH Germany de_DE Austria de_AT Switzerland de_CH Liechtenstein de_Ll Italy it_IT Switzerland it_CH Japan jp_JP South Korea ko_KR Poland pl_PL Russia ru_RU Spain es_ES 324 Diktow HOUR 19 Internationalizing Your Application The locales are likely to be enhanced The latest list of locales can be viewed at http developer android com sdk android 2 1 html locs How the Android Operating System Handles Locale Much like other operating systems the Android platform has a system setting for locale This setting has a default s
331. le application in the emulator This page intentionally left blank HOUR 2 Mastering the Android Development Tools What You l Learn in This Hour Using the Android documentation gt Debugging applications with DDMS gt Working with the Android Emulator Using the Android Debug Bridge ADB gt Working with Android virtual devices Android developers are lucky to have more than a dozen development tools at their dis posal to help facilitate the design of quality applications Understanding what tools are available and what they can be used for is a task best done early in the Android learning process so that when you are faced with a problem you have some clue as to which utili ty might be able to help you find a solution The Android development tools are found in the tools subdirectory of the Android SDK installation During this hour we walk through a number of the most important tools available for use with Android This infor mation will help you develop Android applications faster and with fewer roadblocks Using the Android Documentation Although it is not a tool per se the Android documentation is a key resource for Android developers An HTML version of the Android documentation is provided in the docs sub folder of the Android SDK documentation and this should always be your first stop when you encounter a problem You can also access the latest help documentation online at the Android Developer websit
332. led root Once a layout has been inflated into a View it can be modified programmatically much like a regular layout At this point controls can be populated with data and event listeners can be registered For example to retrieve the EditText_Pwd1 control from the layout view you call the findViewById method as follows final EditText p1 EditText layout findViewById R id EditText_Pwad7 final EditText p2 EditText layout findViewById R id EditText_Pwa2 At this point you register any event listeners on the EditText fields such as those discussed earlier to watch EditText input and match the strings as the user types For example you can register to listen for text change events in the second EditText password field using a TextWatcher and match the contents of the field to that in the first EditText field You can then display the password matching sta tus in the third TextView control we created called TextView_PwdProblen final TextView error TextView layout findViewById R id TextView_PwoProblem p2 addTextChangedListener new TextWatcher Override public void afterTextChanged Editable s String strPass1 p1 getText toString String strPass2 p2 getText toString if strPass1 equals strPass2 error setText R string settings pwd_equal else error setText R string settings_pwd_not_equal other required overrides do nothing H The TextWatcher has a number of me
333. lete feature 416 automated testing 373 adding more tests 379 380 creating test cases 375 377 creating test projects 374 375 explained 374 logging application information 374 running automated tests 378 379 availability of servers checking 261 avatars adding to settings screen layout 219 220 bitmaps generating 229 saving 228 229 scaling 229 230 transformations 230 designing 217 219 gallery 227 228 ImageButton controls handling events 222 223 setting images of 221 222 launching activities and handling results 224 225 photo taking with camera 225 227 uploading 288 AVDs Android Virtual Devices advantages 24 creating 17 18 241 background operations in App Widgets 314 315 creating services 316 317 starting stopping services 317 318 handling 268 269 273 backward compatibility designing for 342 battery life 363 BATTERY_STATS permission 363 Been There Done That application activities 96 97 105 106 activity dialogs 181 AlertDialog class 182 CharacterPickerDialog class 182 custom password dialog 188 193 DatePickerDialog class 182 187 defining 183 Dialog class 182 dismissing 184 initializing 183 launching 183 life cycle of 182 183 ProgressDialog class 182 removing from use 184 TimePickerDialog class 182 App Widget adding to Home screen 312 313 Android manifest file updates 307 AppWidgetProvider class implementation 309
334. lications through the Android Market you must register as a develop er Registering as a developer verifies who you are to Google and signs you up for a Google Checkout account which the Android Market uses to disperse revenue from applications sales back to developers To sign up for Android Market follow these steps 1 Browse to http market android com publish signup as shown in Figure 24 1 market Distribute your applications to users of Android mobile phones Android Market enuttes developers 1o easily pubksh and distribute ther apphcations drecthy to users of Andrei compatibae phones E Come one Come all Android Market is open to all Android aplication dewelopees Once segsternd developers have complete control over when and how they make thee applications salable to users Easy and simple to use Start using Andrond Market 3 easy steps regster upload and pubbsh Great 3 Dewlopers can easily manage thew application portfoho where they can wew information about downloads ratings and comments Developers can aiso easy puthsh updates and new versions of thew apps To leam mare about how to use Android Markt visit the Android Market help contor 2008 Google Andenid com Prhmcy Policy Program Policies Terms gi Use Sign in to Andrond Market Publisher Sito with your Google Account Enet fewwword Stay oped Senin Can access your accourt Vort have a Google Account Cremo on account now 2 Sig
335. lines of the version text 3pt After you have saved the resource files you can begin to use your new resources in the splash xml layout resource file Updating the Splash Screen Layout You could modify the existing splash xml layout but it is sometimes easier to start from scratch by using the Eclipse layout resource editor to remove all existing con trols You then take the following steps to generate the layout you want based on your intended layout design 1 Begin by adding a new LinearLayout control and setting its background attribute to android color black and its orientation to vertical All subsequent controls will be added inside the LinearLayout control It s often easiest to use the Outline view of Eclipse to add View controls within one another or move them around 2 Adda TextView control called TextViewTopTitle Set layout_width to fill_parent and layout_height to wrap_content Set the control s text attribute to the string resource its textColor attribute to the yellow color resource and its textSize to the dimension resource you created 3 Adda TableLayout control called TableLayout 1 Set layout_width to fill_parent and layout_height to wrap_content Also set the stretchColumns attribute to to stretch any column as necessary to fit the screen 118 HOUR 7 Implementing an Animated Splash Screen 4 Within the TableLayout control add a TableRow control Within the TableRow control add two ImageView co
336. ll amount of user interaction without creating an entirely new activity In such instances creating an activity dialog can be very handy Dialogs can be helpful for creating very simple user interfaces that do not necessitate an entirely new screen or activity to function Instead the calling activity dispatches a dialog which can have its own layout and user interface with buttons and input controls Table 3 2 lists the important methods for creating and managing activity dialog windows TABLE 3 2 Important Dialog Methods of the Activity Class Method Purpose Activity showDialog Shows a dialog creating it if necessary Activity onCreateDialog Is a callback when a dialog is being created for the first time and added to the activity dia log pool Activity onPrepareDialog Is a callback for updating a dialog on the fly Dialogs are created once and can be used many times by an activity This callback enables the dialog to be updated just before it is shown for each showDialog call Activity dismissDialog Dismisses a dialog and returns to the activity The dialog is still available to be used again by calling showDialog again Activity removeDialog Removes the dialog completely from the activity dialog pool Activity classes can include more than one dialog and each dialog can be created and then used multiple times 54 Oat HOUR 3 Building Android Applications There are quite a few types of ready
337. lor scheme as the other screens To translate the rough design into the appropriate layout design you need to update the res layout game xml layout file and the QuizGameActivity class RelativeLayout works especially well for displaying icon graphics in each of the four corners of the screen You can also use another RelativeLayout to display each question to the user using one ImageView control and one TextView control as well as two Button controls to handle responses Figure 12 2 shows the basic layout design of the game screen Designing the Game Screen LinearLayout Vertical Orientation RelativeLayout ImageView Question Specific Graphic TextView Question Specific Text Button Yes Button No Each time the user clicks a Button control the game screen will update the ImageView and TextView controls to display the next question To smoothly transi tion and animate from one question to the next you can use the special controls ImageSwitcher and TextSwitcher which are subclasses of the ViewSwitcher class A ViewSwitcher control can animate between two child View controls the current View control and the next View control to display Only one View control is dis played at any time but animations such as fades or rotates can be used during the transition between View controls These child View controls are generated using ViewFactory For example ImageSwitcher and its corresponding ViewFactory c
338. ls 203 204 generating with ViewFactory 204 205 ImageSwitcher 206 207 TextSwitcher 205 billing Android Market 401 bindService method 317 bitmaps generating 229 saving 228 229 scaling 229 230 transformations 230 Blog tab Android documentation 28 Bluetooth 363 BroadcastReceiver class 363 Browser application 37 Browser content provider 360 browsing file system with DDMS 31 build errors resolving 420 Button controls configuring 170 171 handling button clicks 171 172 buttons handling button presses 211 212 Upload Application 397 Button_Friend_Email control 296 C call state information retrieving 279 callback methods activities 49 50 CallLog 360 camera 225 227 cancellation handling 270 271 CDMA phones determining 279 280 certificate authorities 388 certification programs 380 changing locales 324 CharacterPickerDialog 182 checking network status 260 261 server availability 261 Chippy s Revenge game activity requirements 44 45 application features 43 44 application functionality 45 46 choosing target languages 331 target locales 331 target platform 342 Class command New menu 415 classes See specific classes Clean command Project menu 420 clearAnimation method 122 123 clearing progress indicators 270 clicks handling 171 172 client server testing 370 code comments 416 code editing 416 417 code forma
339. manifest file Organizing Content with Live Folders A live folder is a special type of object that when clicked shows data from an appli cation acting as a content provider For example a music application might allow the user to create live folders for specific music playlists which could be placed on the Home screen via a long click on the home screen then choosing Folders To create a live folder an application must create an Activity class that responds to the intent action ACTION_CREATE_LIVE_FOLDER and have a corresponding ContentProvider object for the data contents of the live folder See the documenta tion for the android provider LiveFolders package for more details Integrating with Global Search Android allows applications to be searchable at a system wide level This is done by configuring the application and providing custom Activity classes that handle the various commands required to handle the search actions and search results Additionally applications can provide search suggestions that will display when a user is typing their search criteria in the search field the Quick Search Box If your application is content rich either with content created by users or with con tent provided by you the developer then integrating with the global search mecha nism of Android can provide many benefits and add value to the user The applica tion data becomes part of the overall handset experience is more accessible and you
340. me application you might return from the Scores Play and Help screens to the Menu screen by finishing ScoresActivity PlayActivity or HelpActivity Working with Intents An Intent object encapsulates a task request used by the Android operating system When the startActivity method is called with the Intent parameter the Android system matches the Intent action with appropriate activity on the Android system That activity is then launched The Android system handles all intent resolution An intent can be very specific including a request for a specific activity to be launched or somewhat vague requesting that any activity matching certain criteria be launched For the finer details on intent resolution see the Android documentation Passing Information with Intents Intents can be used to pass data between activities You can use an intent in this way by including additional data called extras within the intent To package extra pieces of data along with an intent you use the putExtra method with the appropriate type of object you want to include The Android pro gramming convention for intent extras is to name each one with the package prefix for example com androidbook chippy NameOfExtra For example the following intent includes an extra piece of information the current game level which is an integer Intent intent new Intent getApplicationContext HelpActivity class intent putExtra com androidbook chip
341. men game_question_size int titleColor res getColor R color title_color int shadowColor res getColor R color title_glow textView setTextSize dimension textView setTextColor titleColor textView setShadowLayer 10 5 5 shadowColor return textView Note that much like the MyImageSwitcherFactory implementation the MyTextSwitcherFactory also implements the makeView method this time gen erating the appropriate TextView control with some text size color and gravity attributes Working with TextSwitcher The TextSwitcher control enables an activity to animate between two TextView controls You need to include a TextSwitcher control called TextSwitcher_ QuestionText in the layout of the game screen to display each trivia question to the user Initializing a TextSwitcher Control To initialize a TextSwitcher control you simply set its ViewFactory and then use the setCurrentText method like so TextSwitcher questionTextSwitcher TextSwitcher findViewById R id TextSwitcher_QuestionText questionTextSwitcher setFactory new MyTextSwitcherFactory questionTextSwitcher setCurrentText First Text String Updating a TextSwitcher Control When you want to update a TextSwitcher control with a new TextView control you can call the setText method 206 HOUR 12 Adding Application Logic TextSwitcher questionTextSwitcher TextSwitcher findViewById R id TextSwitcher_QuestionText questionTextSwitch
342. ment Tools PocketGear 404 449 Project menu commands POST method 286 288 power settings 363 preferences activity preferences 110 application preferences accessing 46 47 creating 106 107 debug configuration 108 retrieving shared preferences 107 108 saving shared preferences 107 privacy concerns 302 processScores method 269 programming languages support for 23 progress bars 257 clearing 270 indicating network activity with 262 determinate progress 263 indeterminate progress 263 progress dialogs 263 264 starting 268 progress dialogs 263 264 dismissing 273 starting 272 progress updates handling 269 270 ProgressBar control 263 ProgressDialog class 182 263 264 ProGuard 406 Project menu commands Clean 420 How can we make this index more useful Email us at indexes samspublishing com 450 projects projects adding to Eclipse 13 creating 10 11 103 debug and run configurations 18 19 debugging with DDMS 21 22 29 30 developing without Eclipse 39 editing project resources AndroidManifest xml file 13 15 res files 15 16 string resources 16 launching on handset 22 23 with emulator 19 21 project files 12 13 project resources adding 103 104 properties of App Widgets 306 307 prototypes activities 105 106 application preferences creating 106 107 retrieving shared preferences 107 108 saving shared preferences 107 debug
343. mobile devices Not every Android device is guaranteed to have network support although it s generally a pretty safe bet that some form of access to the Internet will be available Keep this fact in mind when making assumptions about how much your application will rely on a network Enabling Network Testing on the Emulator You do not need to make any changes to the emulator to write network enabled applications The emulator will use the Internet connection provided by your devel opment computer and simulate true network coverage Also the emulator has a number of settings for simulating network latency and network transfer speeds which can give you a better idea of the actual experience a user would have For details on the network debugging features of the emulator see the Android emulator documentation Because the emulator uses your desktop Internet connection it is likely to be higher speed than a true Android device Internet connection will be Testing Network Applications on Hardware As usual the best way to test network enabled applications is on the target Android device There are a number of network related settings on an Android device You configure these settings through the Settings application on the device gt Airplane Mode This mode will block all network activity according to most You can also find a lot of information about the phone service by clicking on the Settings application from th
344. n What You ll Learn in This Hour gt Designing the main menu screen gt Implementing the main menu screen layout gt Working with ListView controls gt Working with other menu types In this hour you learn about some of the different menu mechanisms available in Android You begin by implementing the main menu screen of the Been There Done That application using new controls such as ListView and RelativeLayout You then learn about other screens that can benefit from special types of menus such as the options menu Designing the Main Menu Screen To design the main menu screen you begin by roughly sketching what you want it to look like If you review the screen requirements you see that this screen provides essential navi gation for the rest of the application Users can choose from four different options play the game review the help configure the settings or view the high scores Figure 8 1 shows a rough design of the main menu screen 128 FIGURE 8 1 Rough design for the Been There Done That main menu screen HOUR 8 Implementing the Main Menu Screen Game Features Play Scores Settings and Help Picture There are a number of different ways you could implement the main menu screen For example you could create a button for each option listen for clicks and funnel the user to the appropriate screen However if the number of options grows this method would not scale well Therefore a list of
345. n I do A First dry your tears and delete that angry ranting email you were about to send off to the Android development team This kind of thing is annoying and sometimes downright embarrassing but it happens a lot In some cases you can avoid surprises like this by testing your application against the open source project for the upcoming Android SDK release but there s no guarantee that a specific handset or operator won t modify the firmware release adding and removing features at will Sometimes you won t know there s a problem until you get a complaint from someone in Sao Paulo or Beijing or perhaps most cringe worthy from your boss Here a solid response plan is a must Designate someone poor sod in advance to stay on top of Android SDK releases to fix bugs and to publish application updates to users 344 HOUR 20 Developing for Different Devices Q How can I listen for orientation changes and load the appropriate portrait or landscape layout so my application screens always look nice A Your application does not have to listen for orientation changes to do this Instead just make sure you have the appropriately qualified layout resources using the port or land qualifier The Android operating system will auto matically load the appropriate layout whenever the orientation of the device changes As with any other resource make sure the portrait and landscape resources contain the same child views so you don t
346. n This Book This book presents several types of sidebars for special kinds of information gt Did You Know messages provide useful information or hints related to the current text gt By the Way messages provide additional information that might be interesting or rel evant gt Watch Out messages provide hints or tips about pitfalls that may be encountered and how to avoid them This book uses the following code related conventions gt Code and programming terms are set in a monospace font gt is used to signify that the code that follows should appear on the same line as the preceding code gt Exception handling and error checking are often removed from printed code samples for clarity and to keep the book a reasonable length This book uses the following conventions for step by step instructions and explanations gt The core application developed in this book is developed iteratively Generally this means that the first time a new concept is explained every item related to the new concept is discussed in detail As we move on to more advanced topics in later lessons 5 What Conventions Are Used in This Book we assume that you have mastered some of the more rudimentary aspects of Android development from previous chapters and we do not repeat ourselves much In some cases we instruct you to implement something in an early lesson and then help you improve it in a later chapter We assume that you ll re
347. n a per project or workspace wide basis Dozens of rules can be applied and modified to suite your own style Organizing Code Sometimes formatting code isn t enough to make it clean and readable Over the course of developing a complex activity you might end up with a number of embedded classes and methods strewn about the file A quick Eclipse trick comes to the rescue With the file in question open make sure the outline view is also visible Simply click and drag methods and classes around in the outline view to place them in a suitable logical order Do you have a method that is only called from a certain class but available to all Just drag it in to that class This works with almost any thing listed in the outline including classes methods and variables Fun with Refactoring Do you find yourself writing a whole bunch of repeating sections of code that look for instance like this TextView nameCol new TextView this nameCol setTextColor getResources getColor R color title_color nameCol setTextSize getResources getDimension R dimen help_text_size nameCol setText scoreUserName table addView nameCol Fun with Refactoring 419 This code sets text color text size and text If you ve written two or more blocks that look like this your code could benefit from refactoring Eclipse provides two very useful tools Extract Local Variable and Extract Method to speed up this task and make it almost triv
348. n in with the Google Account you want to use At this time you can t change the associated Google Account but you can change the contact email addresses for applications independently 3 Enter you developer information including your name email address and website as shown in Figure 24 2 Selling on the Android Market 397 reser FIGURE 24 2 loper Signup i gt C f r hitp marketandroid com publish signup eR gnaao1 ANNES P ai er profile page market Getting Started Before you can publish software on the Andioid Market you must do three things Create a developer profile Pay a registration fee 25 00 with your credit card using Google Checkout Agree to the Android Market Developer Distnbultion Agreement Details Your eavalopar prosa ait dalerming how yeu appaar ta customers an me Android Lkweat Developer Name VAD appear to users under the name of your appicatan Email Address Website URL Phone Number laclude country code and area code tiy do wo aak for this Email updates Z Contact me occasionally stout development and Market opportunities 2010 Google Android Market Developer Disinhution Agreement Google Terma ol Senice Pracy Policy 4 Confirm your registration payment as of this writing 25 USD Note that Google Checkout is used for registration payment processing 5 Provide information for a Google Checkout Merchant account This is manda tory when signing up a
349. nce of the SharedPreferences object and use the Editor object to make the changes and commit them In the following example you save two preferences the user s name and age import android content SharedPreferences 1S ore SharedPreferences settings getSharedPreferences GAME_PREFERENCES MODE_PRIVATE SharedPreferences Editor prefEditor settings edit prefEditor putString UserName JaneDoe prefEditor putInt UserAge 22 prefEditor commit You can also use the shared preferences editor to clear all preferences using the clear method and to remove specific preferences by name using the remove method Retrieving Shared Preferences Retrieving shared preference values is even simpler than creating them because you don t need an editor The following example shows how to retrieve shared prefer ence values SharedPreferences settings getSharedPreferences GAME_PREFERENCES MODE_PRIVATE if settings contains UserName true We have a user name String user Settings getString UserName Default You can use the SharedPreferences object to check for a preference by name retrieve strongly typed preferences or retrieve all the preferences and store them in a map Although you have no immediate needs for shared preferences yet in Been There Done That you now have the infrastructure set up to use them as you need them within all the application activities This will be handy when you
350. ncel buttons that you d see on a web form A Mobile input forms may certainly be designed using this traditional approach but consider the overhead in terms of state management Activity life cycle events such as suspend and resume would need to save and restore pending input A common approach for mobile input forms is to commit form fields as they are completed Q Does a Spinner control have to be populated from an array A No the underlying data of a Spinner control can be populated from numerous data sources using a data adapter For example the contents of a Spinner con trol might instead come from a database Workshop 179 Workshop Quiz 1 True or False EditText controls are derived from TextView controls 2 What types of button controls are available on the Android platform A Button B TextButton C ImageButton 3 True or False You can store Calendar data in SharedPreferences Answers 1 True The TextView class with its familiar attributes and methods such as getText and setText is the base class of the EditText class 2 A and C There are two button controls in Android Button is a simple button with a text label ImageButton is a button with a Drawable graphic label 3 False The only types supported by SharedPreferences are Boolean float int long and String To save dates or times consider storing them as long values milliseconds from epoch Exercises 1 Adda Toast to the Password
351. nctionality should be encapsulated within the QuizScoresActivity class This screen should do the fol lowing gt Display top score statistics gt Show the latest score if the user is coming from the game screen Figure 6 5 shows a mockup of the scores screen 12345 12344 PEEN v ewNUANERWN x Ke r 12335 12245 12222 11667 11345 11234 9 10000 10 1234 te 123 12 5 122 31 Defining Settings Screen Features The settings screen allows users to edit and save game settings including username and other important features Its functionality should be encapsulated within the QuizSettingsActivity class This screen should do the following gt Allow the user to input game settings gt Allow the user to invite friends to play Designing an Android Trivia Game Figure 6 6 shows a mockup of the basic settings screen AME 8 26 pm Settings Nickname Q NAD Email s nad fakeschool edu Password j Password Set Birth Date January 21 1988 ws Gender Defining Game Screen Features The game screen displays the trivia quiz Its functionality should be encapsulated within the QuizGameActivity class This screen should do the following gt Display a series of yes no questions gt Handle input and keep score and state of the quiz gt Transition to the scores screen when the user is finished playing 101 FIGURE 6 6 The Been There Done That set tings
352. ncvew HorizontaiScouView Dimageswacher Views OGesweOverayvew Osutaceview Oven Qviewsne Bansiogdiock noCompietetextview Domon create Eocene E Proser Sooty Setect ail on focus Shadow color Shacow ax Sracom oy Sacow acs Sound effects enabie Sie Tag Text Gsinng hetio Text appearance Text color Text color hightigne Test colcr him Text coler tink Ten saie X Text sve Text styie Typeface vismut wan Layout manem Problems Javadoc Deciaration Conioie Outline O Uneartxyout O Teven Like most other user interface designers the layout resource editor works well for basic layout design However the layout resource editor does not fully support all View controls For some of the more complex user interface controls you might be forced to edit the XML by hand You might also lose the ability to preview your lay out if you add any of these controls to your layout In such a case you can still view your layout by running your application in the emulator or on a handset Displaying an application correctly on a handset rather than the Eclipse layout edi tor should be a developer s primary objective Designing Layouts Using XML You can edit the raw XML of a layout file directly If you click on the project file res layout main xml you see the main xml tab which shows you the raw XML of the layout file As you gain experience developing layouts you should familiarize
353. nd paying to be an Android Developer 6 Agree to link your credit card and account registration to the Android Market Developer Distribution Agreement When you successfully complete these steps you are presented with the home screen of the Android Market which also confirms that the Google Checkout Merchant account was created Uploading an Application to the Android Market Now that you have an account registered for publishing applications through Android Market and a signed application package you are ready to upload it From the main page of the Android Market website sign in and click the Upload Application button as shown in Figure 24 3 398 HOUR 24 Publishing on the Android Market FIGURE 24 3 Android Market ei c Tr hnp marketandroid com pubih Home listings EER Ars 2 market moia rer Grestoprrent prones gt aac YO CY pachare m wher bed freee OW Gogs Antpa Ure Devotee Deringer Aeervers Gage Temm gi Sere Precy Pory You now see a form as shown in Figure 24 4A for uploading the application pack age FIGURE 24 4A j Uploading an gt C fi httpy market android com publish HometEDIT A amp Dr 7 application yoo pees anne ee tormi gt market Figure 24 4B shows the screen allowing the developer to choose which countries to ship the application to All countries that do not allow paid applications to be exported to are disabled Selling on the Android Market 399 FIGURE 24 4B Choosing the
354. nd under the Emulator Control tab in DDMS These events are all one way meaning that they can be initiated from DDMS not from the emulator to DDMS These features work for emulators only not for handsets For handsets you must By the use real calls and real messages ay Simulating Incoming Calls to the Emulator You can simulate incoming voice calls by using the DDMS Emulator Control tab see Figure 2 5 This is not a real call no data voice or otherwise is transmitted between the caller and the receiver 32 FIGURE 2 5 Using the DDMS Emulator Control tab left to place a call to the emulator right HOUR 2 Mastering the Android Development Tools Fie Eon Refactor Run Navigate Search Project Widow Help f m gt fr vor e ligw 8 A7 BEB apime Incoming call T Devices ce0 a2 clu Name O emsaor 5554 ir Vania AVD 2L debug system_process a500 comandroid phone 01 comandroid inputmethod Jatin 2 anrod process acore EO comandroidalarmelock 603 awodd process media sll comandroiddocie droid 8414 8700 comandroig email B COM ancrord browser BENE Telephony Status Voice home vi Speet f v Datx home 7 Latency None v Telephony Actions Incoming number 5551212 o boxe sms Try It Yourself Simulate an Incoming Call to an Emulator To simulate an incoming call to an emulator running on your machine follow these steps 1 In DDMS choose the emulator you want to call
355. ndroid layout_gravity center_horizontal android layout_height wrap_content android shadowRadius 5 android gravity center android textColor color menu_color android shadowColor color menu_glow android shadowDy 3 android shadowDx 3 gt It can be helpful to set the text attribute to a test string so you can see how the TextView control s attributes look in the Eclipse resource designer This string will be programmatically overwritten by the ListView control At this point save the menu_item xml layout file 133 woii ow 134 HOUR 8 Implementing the Main Menu Screen Working with the ListView Control Now you should switch your focus to the QuUizMenuActivity java file Here you need to flesh out the ListView control First you need to fill the ListView control with content and then you need to listen for user clicks on specific items in the ListView control and send the user to the appropriate screen Filling a ListView Control Your ListView control needs content ListView controls can be populated from a variety of data sources including arrays and databases using data adapters In this case you have a fixed list of four items so a simple String array is a reasonable choice for your ListView data Begin by retrieving an instance of the ListView control just after the setContentView method call in the onCreate method of your activity To pop ulate your ListView control
356. ndroid SDK and used a Hashtable member variable to store a batch of questions parsed from XML Finally you used the application s SharedPreferences to keep track of settings and game state information Workshop 215 Q amp A Q If I m storing images locally can use the ImageSwitcher setImageURI method instead of the setImageDrawable method A Of course In fact we recommend it If the graphic is locally available use the setImageURI method to greatly simplify the code for loading a graphic into an ImageSwitcher or ImageView control There is no need for streams or Drawable objects in memory When using a ViewSwitcher control can set my own animations A Yes you can create any animation you want between the old View control and the new View control However keep in mind that once a View control has been switched out the only way to bring it back is by setting it as the next View control There is no notion of a previous View control with the ViewSwitcher control Workshop Quiz 1 What subclasses are available for the ViewSwitcher class A TextSwitcher B VideoSwitcher C ImageSwitcher D AudioSwitcher 2 True or False The TextView controls used by a TextSwitcher control must be defined before the TextSwitcher control can be used 3 True or False Standard packages such as java io java math java net and java util are available within the Android SDK 216 HOUR 12 Adding Application Logic An
357. ndsets while others occur only on specific handsets Functional defects that is features of an application that are not working properly are only one type of defect You must look beyond these and test whether an application works well with the rest of the Android operating system in terms of performance responsiveness usability and state management Developing Good Test Plans Testers must rely heavily on an application s functional specification as well as any user interface documentation to determine whether features and functionality have been properly implemented The application features and workflow must be thor oughly documented at the screen level and then validated by testing In larger teams it is not uncommon for interpretive differences to exist between the function al specification the developer s implementation and the tester s resulting experi ence These differences must be resolved as part of the defect resolution process Testers of Android applications have a variety of tools at their fingertips While some manual testing is essential there are now numerous opportunities for automated testing to be incorporated into testing plans 370 HOUR 22 Testing Android Applications Test plans need to cover a variety of areas including the following gt Functional testing This testing ensures that the features and functions of the application work correctly as detailed in the application s functional s
358. ne 2010 Trademarks All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized Sams Publishing cannot attest to the accuracy of this information Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark Warning and Disclaimer Every effort has been made to make this book as complete and as accurate as possible but no warranty or fitness is implied The information provided is on an as is basis The authors and the publisher shall have neither liability nor responsibility to any person or entity with respect to any loss or damages arising from the information contained in this book or from the use of the programs accompanying it Bulk Sales Sams Publishing offers excellent discounts on this book when ordered in quantity for bulk pur chases or special sales For more information please contact U S Corporate and Government Sales 1 800 382 3419 corpsales pearsontechgroup com For sales outside of the U S please contact International Sales international pearson com Editor in Chief Mark Taub Acquisitions Editor Trina MacDonald Development Editor Michael Thurston Managing Editor Kristy Hart Project Editor Betsy Harris Copy Editor Kitty Wilson Indexer Erika Millen Proofreader Sheri Cain Technical Editor Jonathan Jackson Publishing Coordinator Olivia Basegio Book Designer Gary Adair Senior
359. ne what versions of the SDK your target users are using in the field Backward compatibility in the Android platform is not guaranteed Developers have experienced some rough patches when classes in the latest SDK are changed or deprecated For example some applications written for Android SDK 1 5 were bro ken by the Android 1 6 release and then they worked again in Android 2 0 This can be very frustrating to developers and users Specifying a Project s Target SDK You can specify an application s SDK support by compiling against the appropriate SDK version which is set in the project settings as well as the Android manifest file You can also specify certain application resources to work with certain SDK versions by using the appropriate resource directory qualifiers listed in Table 20 1 Designing Applications for Backward Compatibility To target the largest number of handsets you need to target multiple versions of the SDK However setting required SDK versions in the Android manifest file limits the versions of the SDK on which your application can be installed There is a workaround here though Because Java uses reflection you can query classes and methods without including them in the import statements You could therefore set the minimum SDK version to the lowest possible version that your application can reasonably use Then application logic can be used by determin ing what s actually available at runtime
360. need layout files to match each activity you will be creating First you rename the main xml layout splash xml Then you copy the splash xml file five more times resulting in one layout for each activity game xml help xml menu xml scores xml and settings xml You may notice that there is an error in each Layout file This is because the TextView control in the layout refers to the string hello string which no longer exists For each layout file you need to use the Eclipse layout editor to change the String resource loaded by the TextView control For example game xml needs to replace the reference to string hello with the new string you created called string game Now when each layout loads it displays the screen it is supposed to represent Adding Drawable Resources While you are adding resources you should change the icon for your application to something more appropriate Starting with a nice public domain image of Earth from NASA you can create a 48x48 pixel PNG file called quizicon png and add this resource file to the drawable resource directory Then you can delete the icon png file used by default In the project code for this chapter and future chapters you will see that there is only a single drawable resource directory named drawable Whenever the Android system goes about picking a drawable resource it only looks in this direc tory instead of the three default directories drawable 1ldpi drawable mdpi
361. need to load the layout itself but you need to interact with specific controls within the layout such as the TextView control in the main xml layout file Layout contents whether Button ImageView or TextView controls are derived from the View class The default layout file created with the Droid1 project contains a TextView control However this TextView control does not have a default name attribute The easiest way to access the right View control is by name so take a moment and set the id attribute of the TextView control using the layout resource editor Call it id TextViewO1 Here s how you would retrieve a TextView object named TextView 1 that has been defined in the layout resource file TextView txt TextView findViewById R id TextViewO7 Working with Files In addition to string graphic and layout resources Android projects can contain files as resources These files may be in any format However some formats are more convenient than others Working with XML Files The XML file format is well supported on the Android platform Arbitrary XML files can be included as resources These XML files are stored in the res xml directory XML file resources are the preferred format for any structured data your application requires How you format your XML resource files is up to you A variety of XML utilities shown in Table 4 5 are available as part of the Android platform 72 HOUR 4 Managing Application Resou
362. network resources The MediaPlayer class android media MediaPlayer can be used to play audio and the MediaRecorder class android media MediaRecorder can be used to record audio Recording audio requires the android permission RECORD_AUDIO permission 353 Diiw waihi 354 FIGURE 21 3 A VideoView control with a MediaControll er control HOUR 21 Diving Deeper into Android Playing and Recording Video You can use the VideoView control to play video content on a screen You can use the MediaController control to provide the VideoView control with basic video controls such as play pause and stop see Figure 21 3 BMS 7 37 pm Multimedia As with audio recording you can use the MediaRecorder class to record video con tent using the built in camera Applications that access the camera hardware must have the android permission CAMERA permission registered and those that record audio using MediaRecorder must register the android permission RECORD_AUDIO permission in the Android manifest file Thus to record video which uses the micro phone and camera both permissions should be added to the Android manifest file Working with 2D and 3D Graphics If you re familiar with computer graphics programming you will be pleased to note that Android has fairly sophisticated graphics capabilities for a mobile device Working with 2D and 3D Graphics 355 Using the Android Graphics Libraries The Android
363. nformation about that activity such as whether it com pleted successfully or was canceled by the user 2 False The ImageButton control is actually a subclass of ImageView However a Button control behaves in a very similar fashion to an ImageButton control because they are both derived from the View class 3 False The Bitmap class encapsulates all bitmap style graphics formats specif ically PNG recommended and JPG supported Exercises 1 Use the Bitmap class to modify an avatar in some way before saving it to the application file For example use the Matrix class to invert all the colors in the graphic inversion 2 Use the createScaledBitmap method of the Bitmap class to generate a scaled version thumbnail of a avatar graphic This page intentionally left blank HOUR 14 Adding Support for Location Based Services What You l Learn in This Hour gt Designing the favorite place feature Using location based services Using geocoding services gt Working with maps In this hour you add a new feature to the Been There Done That application the ability for the user to set his or her favorite place in the world from the settings screen The user can set this information in two ways by using the current location provided by location based services LBS on the handset or by supplying a place name that can be resolved into the corresponding GPS coordinates using the geocoding functionality provided in the
364. ng Indeterminate Progress The simplest ProgressBar control style is a circular indicator that animates see Figure 15 2 This kind of progress bar does not show progress per se but informs the user that something is happening You want to use this style of progress bar when the length of the background processing time is indeterminate FIGURE 15 2 http perlgurl org s An indetermi nate progress animation Displaying Determinate Progress When you want to inform the user of specific milestones in progress you can use the determinate progress bar control This control displays as a horizontal progress bar that can be updated to show incremental progress toward completion see Figure 15 3 To use this progress indicator you use the setProgress method of the ProgressBar control A determinate progress bar As described later in this hour you can put progress bars in the application s title Did you__ bar This can save valuable screen space You often see this done on screens dis ow playing web content Displaying Progress Dialogs You may want to indicate progress in a dialog window as opposed to adding a ProgressBar control to the layout of an existing screen You can use the special Dialog class called ProgressDialog for this purpose For example you can use ProgressDialog windows see Figure 15 4 in the Been There Done That applica tion to inform the user that data is being downloaded and parsed bef
365. ng TAG MyApp Now anytime you use a Log method you supply this tag An informational logging message might look like this Log i TAG In onCreate callback method Q amp A 55 You can use the LogCat utility from within Eclipse to filter your log messages to Did you__ the tag string See Appendix B Eclipse IDE Tips and Tricks for details ow Summary In this hour you ve seen how different Android applications can be designed using three application components Context Activity and Intent Each Android application comprises one or more activities Top level application functionality is accessible through the application context Each activity has a special function and usually its own layout or user interface An activity is launched when the Android system matches an intent object with the most appropriate application activity based on the action and data information set in the intent Intents can also be used to pass data from one activity to another In addition to learning the basics of how Android applications are put together you ve also learned how to take advantage of useful Android utility classes such as application logging which can help streamline Android application development and debugging Q amp A Q How do design a responsive application that will not be shut down during low memory conditions A Applications can limit but never completely eradicate the risk of being shut
366. ng of the contents 147 Dw 148 FIGURE 9 3 The Been There Done That help screen HOUR 9 Developing the Help and Scores Screens At this point save the QuizHelpActivity java file and run the Been There Done That application in the Android emulator After the splash screen finishes choose the help screen option from the main menu The help screen should look much like Figure 9 3 BEE 8 19 pm HelScreen amp Have you Been there Have you done that BEEN THERE DONE TRAT is atrivia quiz dedicated to those Who love travel and adventure By answering a s series of Yes or No questions you gain points toward being the most well travel d and field tested person on the planet Share your experiences and compete with your friends j GAME SETTINGS _ lt TBD gt SUPPORT INF QRMATION Try It Yourself Now that you have the help screen displaying the appropriate information you might want to improve the look of it to more closely match Figure 9 3 Start by changing the font size of the help text in the TextView control Then consider changing other attributes such as padding font text colors and so on For more information see the attributes configured in the TextView implementation provided with the book code Designing the Scores Screen 149 Designing the Scores Screen Now that you ve created the help screen you can turn your attention to another screen with somewh
367. ning an App Widget 311 At this point you need to get the data that will be displayed in the App Widget The getWidgetData method handles this by getting the player identifier from SharedPreferences and then downloading the data from the server You handle the operation this way instead of loading this data straight from SharedPreferences so that you can switch it later to support loading data from friends or other players Next you build up the RemoteViews object The initialization requires not only the layout to use but also the package for where the layout comes from Recall that a RemoteViews object will not be displayed in the same process so more information is needed in order for it to access the resources You have access to the nickname and score information or suitable default values so you can set those via the setTextViewText method passing in both the identifier from the layout and the value The code for the avatar image is similar but first ver ifies that a suitable URL for the avatar is available and that the image can be decoded Finally either the setImageViewBitmap or setImageViewResource method is called to apply the avatar image to the RemoteViews object Finally you have to actually update the App Widget You do this via a call to the updateAppWidget method of AppWidgetManager It requires both the RemoteViews object and the Android ComponentName object of the QuizWidgetProvider retrieved by instantiating t
368. nits that Android supports 65 Dw 66 HOUR 4 Managing Application Resources TABLE 4 3 Dimension Unit Measurements Supported in Android Type of Measurement Description Unit String Pixels Actual screen pixels px Inches Physical measurement in Millimeters Physical measurement mm Points Common font measurement pt Density independent pixels Pixels relative to 160dpi dp Scale independent pixels Best for scalable font display sp The following code retrieves a dimension resource called thumbDim using the getDimension method float thumbnailDim getResources getDimension R dimen thumbDim Working with Drawable Resources Drawable resources such as image files must be saved under the res drawable project directory These types of resources are then compiled into the application package at build time and are available to the application You can drag and drop image files into the res drawable directory by using the Eclipse Project Explorer Again remember that filenames must be lowercase and contain only letters numbers and underscores Working with Images The most common drawable resources used in applications are bitmap style image files such as PNG and JPG files These files are often used as application icons and button graphics but may be used for a number of user interface components As shown in Table 4 4 Android supports many common image formats TABLE 4 4 Image Formats Supported in Android
369. nity to download larger batches of quiz questions in the background to cache for future use in the game or to modify the batch size to down load the optimum number of questions at a time to keep your application respon sive to users and improve user experience Determining Whether the Phone Is CDMA or GSM You can use the getPhoneType method of the TelephonyManager class to deter mine whether a handset is a CDMA or GSM phone Furthermore you can get the unique identifier of the handset by using the getDeviceId method This method 280 HOUR 16 Adding More Network Support returns the IMEI for GSM phones or the MEID for CDMA phones You can also get the unique subscriber identifier such as IMSI for GSM subscribers by using the getSubscriberId method Retrieving SIM Information The TelephonyManager class has a number of methods for retrieving information about the SIM card and SIM provider The following are some examples gt getSimState This method returns the state of the SIM card such as whether the SIM card is in the handset and whether it is locked that is requires a PIN or ready for use gt getSimSerialNumber This method returns the unique serial number of the SIM card gt getSimOperatorName This method returns the name of the SIM provider gt getSimOperator This method returns the mobile country code and net work code for the SIM provider Retrieving Device Voice Mail Information You
370. nt android layout_height wrap_content android layout_centerHorizontal true android layout_alignParentBottom true android id t id widget_score gt lt TextView gt lt RelativeLayout gt Implementing an App Widget Provider Now that the configuration is in place you need to implement the App Widget To do this you need to extend the AppWidgetProvider class which contains five methods that can be overridden gt onUpdate This method is called at each update interval gt onDeleted This method is called each time an App Widget is deleted gt onEnabled This method is called the first time an App Widget is created but not subsequent times gt onDisabled This method is called when the last instance of an App Widget is deleted gt onReceive This method is called for all received broadcast events the default implementation calls each of the previous callback methods e g onUpdate onDeleted onEnabled and onDisabled when necessary This method can be overridden when advanced behavior is required For this example you only need to override the onUpdate method to update the RemoteViews object No persistent setup is needed so you don t need to override any of the other methods That said here s the implementation of the AppWidgetProvider class 310 HOUR 18 Creating a Home Screen App Widget public class QuizWidgetProvider2 extends AppWidgetProvider Override public void
371. ntView method 54 268 setCurrentTabByTag method 155 setCurrentText method 205 207 setEntity method 288 setFactory method 204 setlmageBitmap method 221 setImageDrawable method 206 207 221 setImageResource method 221 setImageURI method 206 215 221 222 setimageViewBitmap method 311 setlmageViewResource method 311 setInAnimation method 207 setInput method 262 269 273 setintent method 140 setLayoutAnimation method 122 setNegativeButton method 192 setOnClickListener method 141 171 setOnClickPendingIntent method 314 setOnltemClickListener method 135 141 How can we make this index more useful Email us at indexes samspublishing com 454 setOnltemSelectedListener method setOnltemSelectedListener method 174 setOnKeyListener method 169 setOnLongClickListener method 223 setProgress method 263 setSelection method 141 173 setText method 147 168 205 207 setTextViewText method 311 setTheme method 350 Settings application 38 settings screens adding avatars to 219 220 adding resources to 165 166 Button controls configuring 170 171 handling button clicks 171 172 defining features of 100 101 designing 161 163 EditText controls committing EditText input 169 170 configuring 168 handling text input 168 SharedPreferences defining SharedPreferences entries 175 reading settings from
372. ntrols For the first ImageView control set the src attribute to the splash1 png drawable resource drawable splash1 Add a second ImageView control and set its src attribute to the splash2 png resource file 5 Repeat step 4 creating a second TableRow control Again add ImageView con trols for splash3 png and splash4 png 6 Much as in step 2 add another TextView control called TextViewBottomTitle within the parent LinearLayout Set its layout_width attribute to fill_par ent and layout_height to wrap_content Set its text attribute to the appro priate string its textColor attribute to the yellow color and its textSize attribute to the dimension resource you created 7 For the version information create one last TextView control called TextViewBottomVersion Set its Llayout_width attribute to fill_parent and layout_height to fill_parent Set its text attribute to the appropriate string its textColor attribute to the grayish color and its textSize attribute to the dimension resource you created earlier Also set its background attrib ute to the color resource dark blue and lineSpacingExtra to the spacing dimension resource value you created 8 Tweak the layout_gravity and gravity settings on the various controls until you think the layout looks reasonable in the Eclipse resource editor preview At this point save the splash xml layout file and run the Been There Done That application in the Android emulator The Splash scre
373. nts such as activities intent filters and other application functionality including configuration for service and content provider implementations Exploring the Android Manifest File ve Downe Browse Attributes for Uses Sit The eats acts tag describes Me SOK features Dut me comtanng package must be naing on to operate comecty MnSOKvenion 7 ove Target SOK version 7 i Max SOK version 7 porting To export te appcation for distribution you Nave the fotiowing extent Ue me Export Wizard t0 export and sgn an APK Export an umigned APS and sign manually gt Unis The coment of the Andros Manitest s made up ct twee sections Yos can also edit De XML dwecdy GB Ansecatce Activities intent Fren growers services anc ieceres fermion Perrmasons cefined and permswom used O innamen bitementaton defines ll Sarr Doeety edt Ne AndroidNunitesumi De Qocumentution Docsmentation trom the Ancrod SOX for AndrodMarstest ami A Bas O O 4 ddar Sere LEN Android Manilest Application Application Toggle 4 Thr anplicahon tag dendes epplicetion level components oaned in the package a well a general appia abon altnbutes V Define an lt apesication gt tag in the AncrosdManitest smn Application Attributes Defines tre altntanes spect bo the appacaton imn ane Mowe Desuggane Mrowse Manage space acovity Browne Allow clear user data leno Browse Hackun
374. nuActivity class 97 QuizScoresActivity class 97 QuizSettingsActivity class 97 277 adding DatePickerDialog to 184 185 adding password dialog to 190 193 onCreateDialog method 296 QuizSplashActivity class 96 QuizTask class 271 272 QuizWidgetProvider class 316 R java class file 62 raw resource files 72 73 accessing 147 148 adding 147 raw sensor data reading 362 reading raw sensor data 362 settings from SharedPreferences 177 178 rearranging tabs 421 lt receiver gt element 307 receiving location updates 245 refactoring 418 420 Reference tab Android documentation 28 referencing application resources 62 system resources 63 region specific resources specifying 326 How can we make this registering activities 86 87 92 for Android Market developer accounts 396 397 regular versioned builds 368 369 relationships enhancing 299 300 RelativeLayout control 115 129 132 release builds 383 release candidate defined 383 packaging and signing 387 390 preparing 385 386 testing 386 387 release process 383 385 packaging and signing 387 390 preparing release candidate build 385 386 testing packaged application 390 392 testing release candidate 386 387 RemoteViews object 311 removeDialog method 53 183 184 192 194 removing applications from Android Market 402 dialogs 184 Rename tool 417 418 renaming items 417 418 representat
375. o Android projects in Eclipse Each Android application has its own private directory on the Android file system for storing application files In addition to all the familiar File and Stream class es available you can access private application files and directories by using the following Context class methods fileList getFilesDir getDir openFileInput openFileOutput deleteFile and getFileStreamPath Accessing Raw File Resources The Android platform includes many of the typical Java file I O classes including stream operations To read string data from a file use the openRawResource method as in the following example InputStream iFile getResources openRawResource R raw quizhelp Now that you have an InputStream object you can read the file line by line or byte by byte and create a string There are a number of ways to do this When you have a proper string with the help text you simply retrieve the TextView control using the findViewById method and set the text using the TextView control s setText method as follows TextView helpText TextView findViewById R id TextView_HelpText String strFile inputStreamToString iFile helpText setText strFile The previous text references a helper method called inputStreamToString which is available with the QuizHelpActivity class implementation provided with this book The method simply reads in an InputStream and returns a Stri
376. o access private data 320 HOUR 18 Creating a Home Screen App Widget Answers 1 False App Widgets can reside within an application that implements an AppWidgetHost object 2 B Both Button and ProgressBar can be used but not WebView 3 True Each cell is typically defined as 74 pixels but when adding up the num ber for multiple cells 2 pixels are subtracted Thus 2 cells wide would be 74x2 2 or 146 pixels 4 A An App Widget runs in another process so must be responsive to requests A thread can t be used because it might be killed when the App Widget returns Therefore a service is started to perform background processing Exercises 1 Modify the App Widget in the Been There Done That application to show information about a friend The XML returned for the friend s scores contains the nickname score rank and avatar URL 2 Add a configuration activity that allows the user to choose which friend to show 3 Continuing with the previous two exercises modify the App Widget to allow multiple instances one showing the user s data and the other showing a friend s data By the HOUR 19 Internationalizing Your Application What You I Learn in This Hour gt Languages supported by the Android platform gt Managing strings and other resources gt Localized formatting utilities gt Other internationalization concerns The mobile marketplace is global serving a variety of users
377. o help with common Android development tasks The Android documentation is an essential reference for developers The DDMS debugging tool which is integrated into the Eclipse develop ment environment is useful for monitoring emulators and devices The Android emulator can be used for running and debugging Android applications virtually without the need for an actual device There are also a number of other tools for interacting with handsets and emulators at the command line level as well as spe cialized utilities for designing Android application user interfaces and graphics as well as packaging applications 40 HOUR 2 Mastering the Android Development Tools Q amp A Q Is the Android documentation installed with the Android SDK the same as the documentation found at http developer android com A No The documentation installed with the SDK was frozen at the time the SDK was released which means it is more specific to the version of the Android SDK you installed The online documentation will always be the lat est version of the Android SDK We recommend using the online documenta tion unless you are working offline or have a slow Internet connection in which case the local SDK documentation will suffice Q Do the different emulator skins have different features A Yes The emulator skins correspond to different screen sizes and orientations They also have keypads and buttons Some have hardware keyboards and other
378. o match a data source to the layout template used by a ListView control to display each list item A RelativeLayout is especially handy when its child View controls need to be aligned to the top bottom left right and center of the parent layout RelativeLayout can also be used to position child View controls relative to one another inside the parent layout True ListActivity simplifies the handling of ListView controls Exercises 1 Review some of the other data adapters available for use with the ListView 2 control Update the ListView control so that each list item contains an ImageView icon and the TextView control Hint Implement a custom data adapter Add a third option to the game screen s options menu to allow the user to access the scores screen Modify the LinearLayout control of menu xml to include an animation that fades in so that the entire main menu screen fades in HOUR 9 Developing the Help and Scores Screens What You l Learn in This Hour gt Designing and implementing the help screen gt Working with files gt Designing and implementing the scores screen gt Designing screens with tabs gt Working with XML In this hour you implement two more screens of the Been There Done That application the help and scores screens You begin with the help screen using a TextView control with text supplied from a text file which allows you to explore some of the file support class
379. o stop itself and returns whether or not the call was successful If you don t care about the result simply call the stopSelf method instead This method call is made when the processing is fin ished within the thread since there is no reason for the service to keep running as it has no further actions to perform in this case The service can be launched again the next time the App Widget updates which for this App Widget is after three hours have elapsed If the App Widget is removed from its host such as the Home screen while an update is taking place the service will need to be terminated in a different way To accomplish this put the following code for the onDeleted method into the AppWidgetProvider implementation Override public void onDeleted Context context int appWidgetIds Intent serviceIntent new Intent context WidgetUpdateService class context stopService servicelIntent super onDeleted context appWidgetIds 318 HOUR 18 Creating a Home Screen App Widget The call to the stopService method triggers a call to the onDestroy method of the Service class implementation which then attempts to interrupt the thread to stop it The example in this hour is pretty simple It will work fine for a single instance of the App Widget However if you want to support multiple instances of the App Widget running simultaneously further code is needed to handle the differentia tion between instances
380. o that in a moment The following are some of the common properties used to define an App Widget gt Size The width and height dimensions of the App Widget defined in density independent pixels dp or dip which correspond to the number of Home screen grid cells the App Widget will require to display correctly The Android Home screen is organized in grid cells that usually correspond to a Did you__ square of 74x74 pixels Only one item such as an App Widget or application ow ee p 3 shortcut can sit in any cell This way items on the Home screen do not overlap gt Update Frequency The time in milliseconds between system calls to the App Widget provider to update the contents of the App Widget gt Initial Layout A layout file to use when the App Widget is initially added This can be changed in code later gt Configuration Activity The definition for an activity to launch to config ure various aspects of the App Widget before it is first displayed To add an App Widget definition for this example start by adding a new XML file called widget_info xm1 under the res xm1 folder In this file place the following App Widget definition lt xml version 71 0 encoding utf 8 gt lt appwidget provider xmlns android http schemas android com apk res android android minWidth 746dp Designing an App Widget 307 android minHeight 746dp android updatePeriodMillis 10800000 android
381. of the lt xml version 1 0 encoding utf 8 7 gt Eclipse lt manifest xmlns android http schemas android com apk res android manifest file packages com androidbook droidl android versionCode 1 android versionName I 0 gt resource editor application android icons drawable icon android labels string app_ name android debuggable t rue gt lt activity android labele string app name android name DroidActivity gt lt intent fllter gt 3 lt caction android names android intent action MAIN gt lt category android name android intent category LAUNCHER gt lt activity gt lt applica n gt uses sdk android targetSdkVersion 7 android maxsdkVersion 7 android minsdkversion 7 gt lt uses adk gt lt uses permission android name android permission CAMBRA gt lt uses permission gt lt manifest gt Figure 5 5 shows the Android manifest file for the Droid1 project you created in the first hour which has fairly simple XML Note that the file has a single lt manifest gt tag within which all the package wide settings appear Within this tag is one lt application gt tag which defines the specific application with its single activity called DroidActivity with an Intent filter In addition the lt uses sdk gt tag is set to 3 Now let s talk about each of these settings in a bit more detail Configuring Basic Application Settings Many of the mos
382. of the class to build initialize and manage the new favorite place picker dialog Implementing the Framework for the Favorite Place Feature 239 n FIGURE 14 6 The favorite place picker Pick a Place ka Favorite Places Olympic National Park Map Coordinates 47 794415 123 68492 Because each of these tasks has been covered in a previous hour we do not go into too much detail here However here are a couple hints for getting things up and running gt Adda helper method called initFavoritePlacePicker to display the favorite place name if it exists and handle Button clicks that launch the favorite place picker dialog This method should closely resemble the initPasswordChooser and initDatePicker methods gt Build the new favorite place picker dialog much like the password dialog you implemented earlier One of the key differences between this new dialog and the password dialog is that the new dialog contains a Button control for launching the Map application gt Build the favorite place picker Dialog one step at a time Begin by having the Dialog save the text inputted as the favorite place name Next to save some mock latitude and longitude information along with the place name When this is all working add a View OnClickListener method for the map Button control and have it display a Toast message that says something like Map Button Clicked 240 waihi HOUR 14 Adding Support for Location Bas
383. ognition server for processing so this feature is not really practical for devices that don t have a reasonable network connection On Android SDK 2 1 and later speech recognition is built in to most pop up key boards Therefore an application may already support speech recognition to some extent without any changes However directly accessing the recognizer can allow for more interesting spoken word control over applications Working with Multimedia Mobile devices are increasingly being used as multimedia devices Many Android devices have built in cameras microphones and speakers allowing playback and recording of multimedia in a variety of formats The Android SDK provides compre hensive multimedia support allowing developers to incorporate audio and visual media still and video into applications These APIs are part of the android media package The Android emulator cannot record audio or video Testing of audio and video recording must be done using a real Android device Also the recording capabili ties of a given device may vary based upon the hardware and software compo nents used For instance Android devices that aren t phones may be lacking microphones and more frequently do not feature cameras Playing and Recording Audio The Android SDK provides mechanisms for audio playback and recording in various formats Audio files may be resources local files or URI objects to shared or
384. om the device You learned how to launch an activity and retrieve its results by using the startActivityForResult and onActivityResult methods Finally you learned about some of the graphics classes available in the Android SDK Q amp A Q By default the ACTION_IMAGE_CAPTURE intent returns a small bitmap graphic of the photo taken by the camera However the full size graphic captured by the camera is much larger Can I access this photograph data A You can control the data returned by camera application by supplying some extra data specifically the EXTRA_OUTPUT field to the intent Q How can I maintain aspect ratio when scaling a Bitmap graphic A To maintain the aspect ratio of a graphic simply scale each axis x and y by the same percentage Don t forget that if you apply scaling to all graphics some may be down scaled while others may be up scaled using the same code Workshop 231 Workshop Quiz 1 Activity results handled by the onActivityResult method are differentiat ed from one another using which parameter A requestCode B resultCode C data 2 True or False The ImageButton control is a subclass of the Button control 3 True or False The Bitmap class only creates traditional bitmap graphics with the bmp extension Answers 1 A The developer defined requestCode is used to determine which activity started with the startActivityForResult method is returning a result resultCode provides i
385. on HOUR 23 Getting Ready to Publish 24 Publishing on the Android Market Part VI Appendixes A Configuring Your Android Development Environment B Eclipse IDE Tips and Tricks C Supplementary Materials 383 395 409 415 423 Table of Contents Introduction 1 Part I Android Fundamentals HOUR 1 Getting Started with Android 7 Introducing Android sssttsstttssninsnsttsonissnissinisinissunissstissanissinissiieninsee 7 Familiarizing Yourself with Eclipse sssrssssiiceiisnssisiinaniinanonenianinin Running and Debugging Applications sssessttssttnsstntnntnnntessen 17 SUMMATY os ince shee tessa davecosssavaraceeesVaunesets taser enetpunscussapeqeeseestonse cians 23 Workshop e a A a net a A HOUR 2 Mastering the Android Development Tools 27 Using the Android Documentation cc 27 Debugging Applications with DDMS ccecce 29 Working with the Android Emulator ec add Using Other Android Tools ooo cccccssssstssstsssttsssttsssnnssntisssiisuniisssiisssisseessseen 38 DUIMIMOLY crcerenicnn annenamascesamnsna E EE E E E eta ental OD OS scat eases Berane Pes rv E A ded cat 40 WorYksShOD iets ceases de siceectdscg decane cageenthecdnadetagdsddonsscssds argenezucasaecctcentcatanscdasgsasssnsscensedfuarsaeiassqeesiectectis 40 HOUR 3 Building Android Applications 43 Designing a Typical Android Application occ ttt 43 Using the Application Context oo 46 Working with Activities ccccccsssssnisssnisssinssissnnssusissunisssnisssiisssissens
386. onUpdate Context context AppWidgetManager appWidgetManager int appWidgetIds WidgetData widgetData new WidgetData Unknown NA getWidgetData widgetData String packageName context getPackageName RemoteViews remoteView new RemoteViews context getPackageName R layout widget remoteView setTextViewText R id widget_nickname widgetData nickname remoteView setTextViewText R id widget_score Score widgetData score if widgetData avatarUrl length gt 0 URL image try image new URL widgetData avatarUr1 Bitmap bitmap BitmapFactory decodeStream image openStream if bitmap null Log w DEBUG_TAG Failed to decode image remoteView setImageViewResource R id widget_image R drawable avatar else remoteView set ImageViewBitmap R id widget_image bitmap catch MalformedURLException e Log e DEBUG_TAG Bad url in image e catch IOException e Log e DEBUG_TAG IO failure for image e else remoteView setImageViewResource R id widget_image R drawable avatar try ComponentName quizWidget new ComponentName context QuizWidgetProvider class AppWidgetManager appWidgetManager AppWidgetManager getInstance context appWidgetManager updateAppWidget quizWidget remoteView catch Exception e Log e DEBUG_TAG Failed to update widget e private void getWidgetData WidgetData widgetData Desig
387. one That application has three activities 2 What data types are supported within application shared preferences A Boolean Float Integer Long and String B Boolean Integer and String C All types that are available in Java 3 True or False You only need to put your base activity class for example QuizActivity in the Android manifest file Workshop 111 Answers 1 False The Been There Done That application has an activity for each screen It also has a base class activity from which all other activities are derived The design has seven total activity classes 2 A Boolean Float Integer Long and String preferences are possible 3 False Each activity needs its own entry in the Android manifest file Exercises 1 Add a preference to the application preferences called lastLaunch Have the QuizSplashActivity read and save the current time each time the onCreate method is called When this preference is read log it using the Log i method 2 Create a set of activity level preferences for QUizSettingsActivity using the getPreferences method instead of the getSharedPreferences method This page intentionally left blank HOUR 7 Implementing an Animated Splash Screen What You l Learn in This Hour gt Designing a splash screen gt Updating the splash screen layout gt Working with animation In this hour we focus on implementing the splash screen of the Been There Done That appl
388. onseHandler lt String gt responseHandler new BasicResponseHandler 297 FIGURE 17 3 The friend request dialog 298 HOUR 17 Adding Social Features String responseBody client execute request responseHandler if responseBody null succeeded true return succeeded Here you use HttpClient to execute an HTTP POST request using form variables to the application server You can form the HttpPost request object by combining the appropriate application server URL with the query variables encoded using the handy UrlEncodedFormEntity class set as the entity for the POST request When the query is fully formed you can execute the request by using the execute method of HttpClient as you have in previous examples Then you simply check the response to determine whether the friend request was successful by checking the resulting ResponseHandler object Displaying Friends Scores Now that players can add friends you need to update QuizScoresActivity to pop ulate the Scores of Friends tab with live data from the application server Luckily this feature is straightforward because the application server is the primary handler for friend relationships Retrieving friends scores is simply a slightly different query on the application server datastore Displaying friends scores on the scores screen is handled exactly the same way as displaying the all time high scores except that the application server URL f
389. opment Hardware for Device Debugging Each Android phone model may have different debugging configurations Your Android device must be enabled for debugging via a USB connection Enabling USB Debugging on an Android Device To enable USB debugging from the Home screen of the Android device select Menu Settings Applications Development and enable the USB Debugging option Different devices may have this option in different places For instance on the Archos 5 Internet tablet it is found under Device Storage amp USB connection USB Connection Mode and then choose Debug Bridge ADB to enable USB debugging 414 Ditow APPENDIX A Configuring Your Android Development Environment During long debugging sessions your phone might often go to sleep To prevent this from happening select the option to have the phone stay awake while charg ing found in the development settings You should see this option in the develop ment settings usually labeled Stay Awake or the likes Configuring Your Operating System for Device Debugging To install and debug Android applications on hardware such as the T Mobile G1 Motorola Droid or Nexus One you might need to configure your operating system to access the phone via USB This is especially true of Windows machines The Android SDK ships with drivers for some devices and you can simply point the Device Manager at the directory where you installed the Android SDK and then plu
390. or all supported versions of Android you can pick and choose the Android SDK versions you want to install and work with using the Android SDK and AVD Manager This tool allows developers to easily upgrade their development environment when a new version of Android comes out which historically has happened quite frequently In addition to various Android target versions to choose from other tools and support can be downloaded such as USB drivers for Windows You need to use the Android SDK and AVD Manager to install the tools Notes on Windows Installations To update your PATH variable to include the Android tools directory right click Computer and choose Properties In Vista you also need to click Advanced System Settings You continue by clicking the Advanced tab of the System Properties dialog and clicking the Environment Variables button In the System Variables section edit the PATH variable and add the path to the tools directory 412 APPENDIX A Configuring Your Android Development Environment Notes on Mac OS X Installations To update your PATH variable to include the Android tools directory you need to edit your bash_profile file in your Home directory Notes on Linux OS Installations To update your PATH variable to include the Android tools directory you need to edit your bash_profile bashrc or profile file Installing and Configuring the Android Plug in for Eclipse ADT The Android Plug in for
391. or documentation that was installed with the Android SDK documentation and is also available online at http developer android com guide developing tools A emulator html Exploring the Android System If you re not already familiar with Android devices now is a good time to learn your way around the Android system as users see it Table 2 1 lists some important fea tures of Android Working with the Android Emulator TABLE 2 1 Android System Screens and Features Feature Description Appearance Home screen Dialer application Messaging application Browser application Contacts application Application sliding drawer Default screen This is a common location for app widgets and live folders Built in application for making and receiving phone calls Note that the emulator has limited phone features Built in application for sending and receiving SMS messages Note that the emulator has limited messaging features Built in web browser Note that the emulator has an Internet connection provided that your machine has one Database of contact information Shows all installed applications From the Home screen pull the gray sliding drawer tab to see all installed applications 37 38 HOUR 2 Mastering the Android Development Tools TABLE 2 1 continued Feature Description Appearance Settings application Built in application to configure a wide variety of
392. or network operations begin again unless you implement the onRetainNonConfigurationInstance method of the Activity class For more information on this type of situation see the write up at the Android developer website http developer android com resources articles faster screen orientation change html Listening for Screen Orientation Changes Applications can register to listen for screen orientation events To do this you request SensorManager by using the getSystemService method You can then query SensorManager for the current orientation using the getOrientation method Alternatively you can implement the OrientationEventListener class android view OrientationEventListener and override onOrientation Changed to register for orientation changes However listening for orientation changes is necessary only when applications require special internal handling of orientation An application that defines a land scape layout resource in the res layout land directory and a default portrait layout resource in the res layout directory will work seamlessly without the need for a listener You can toggle the orientation of the emulator by pressing Ctrl F11 and Ctrl F12 Configuration Management for Android 339 Strategies for Handling Screen Orientation The best way to support different orientations is to design simple enough layouts that work in either portrait or landscape mode without modifications For example
393. or the data request includes the identifier of the player The application server then knows you want to filter the scores to just those connected to that player From an implementation perspective you can simply create another instance of ScoreDownloaderTask to retrieve these scores and populate the Scores of Friends tab see Figure 17 4 When you have the scores screen working with live data you can remove the mock XML resource files and any associated code from the project Adding Friend Support to Your Application 299 FIGURE 17 4 The Scores of Friends tab Little Fawn This Tiger Enhancing Player Relationships Enabling friend relationships can greatly enhance the experience for users in a vari ety of ways above and beyond what you have implemented thus far Adding friend support may seem like a very lightweight social feature but imagine how you can build up more social features from this simple starting point Player relationships allow developers the flexibility to enhance applications in a variety of ways such as the following gt The application server could send an email invitation to any friend who did not already exist in the database gt Players do not need to be restricted to the Android platform Other platforms web iPhone BlackBerry and so on could easily be added This means friends could contact the same application server and play each other across platforms gt Friend relationships could be one
394. ordingly Button setPassword Button findViewById R id Button_ Password setPassword setOnClickListener new View OnClickListener public void onClick View v showDialog PASSWORD_DIALOG_ID 3 Figure 11 6 shows the resulting settings screen with Dialog controls Nickname NAD Email gt nad fakeschool edu Password _ r j Password Set Birth Date Pick Date R January 21 1988 Gender 193 FIGURE 11 6 The complete Been There Done That set tings screen 194 HOUR 11 Using Dialogs to Collect User Input Summary In this hour you learned how an activity can use Dialog controls to simplify screen functionality and layout specifically on the settings screen of the Been There Done That application A dialog can be used to display appropriate information to the user in the form of a pop up window There are Dialog types for inputting dates times and special characters as well as helper Dialog types for showing progress or displaying alert messages You can also create custom Dialog controls Q amp A Q A How is dialog information saved within an activity Each activity keeps a pool of Dialog controls around for use and will reuse a Dialog control when asked to be shown again Basically a dialog is shown using the showDialog method and added to the pool Each dialog is dis missed but sticks around in the pool until either the activity is destroyed or the remo
395. ore displaying the appropriate screen of the application 264 FIGURE 15 4 Informing the user that trivia questions are being down loaded HOUR 15 Adding Network Support Been There Done That be TA O Trivia Quiz od gt Downloading trivia questions Here is the code needed to programmatically create and display the ProgressDialog class ProgressDialog pleaseWaitDialog ProgressDialog show QuizGameActivity this Trivia Quiz Downloading trivia questions true You can use the dismiss method to dismiss pleaseWaitDialog control when you have completed any background processing pleaseWaitDialog dismiss The pleaseWaitDialog control can be cancelled by the user if a fifth parameter is added to the show method and set to true In this case we don t allow the user to cancel the dialog because we want it showing during the entire download In the example code which shows the final results for this hour you ll see we do allow it to be cancelled and you can read about it later in this hour Now you know how to create progress bars and display them in dialog windows using ProgressDialog control Because the progress you want to indicate should actually be taking place asynchronously it s time to turn our attention to back ground processing Running Tasks Asynchronously 265 Running Tasks Asynchronously Despite rapidly evolving technology mobile wireless networks still provi
396. ore the favorite place dialog layout For this purpose you add a new layout resource called res layout fav_place_dialog xml to the project This layout is pretty straightforward All custom dialog controls are encapsulated within a vertically oriented LinearLayout control First you have a TextView con trol to display the label for choosing a favorite place Next you need to display the Implementing the Framework for the Favorite Place Feature 237 EditText input control for the user to type the place name next to a Button con trol to allow the user to launch the Map application You can easily organize the EditText and the Button controls side by side using RelativeLayout Finally you include two TextView controls one to display the label for the GPS coordinates and one to show the actual GPS coordinate data which is read only in the Been There Done That application Figure 14 4 shows the layout for the Favorite Place picker dialog FIGURE 14 4 The favorite place dialog lay TextView Favorite Place oyi EditText Favorite Place Input Button Launch Map TextView Coordinates LinearLayout Vertical Orientation TextView Show GPS Coordinates Implementing the Framework for the Favorite Place Feature Before you can turn your attention to the more interesting aspects of adding LBS support to the Been There Done That application you need to leverage many of the skills discussed in previous h
397. ored locally on By the the handset Attempting to use remote Uri addresses is not recommended due ay to decreased application performance and responsiveness Setting the Image of an ImageButton Control As with an ImageView control there are several different ways to set the graphic shown in an ImageButton control including the following gt setImageBitmap Use this method to set the graphic shown on the ImageButton control to a valid Bitmap object gt setImageDrawable Use this method to set the graphic shown on the ImageButton control to a valid Drawable object gt setImageResource Use this method to set the graphic shown on the ImageButton control to a valid Resource identifier gt setImageURI Use this method to set the graphic shown on the ImageButton control to a valid Uri address In some circumstances the ImageButton control will cache the graphic it is dis Watch playing and continue to do so even if you use one of the methods to change the ut graphic One workaround for this is to call setImageURI nu11 to flush the previ ous graphic and then call setImageURI again with a Uri set to the new graphic to display the ImageButton control Here s a handy trick for accessing application resources such as Drawable resources using a specially constructed Uri address This trick allows you to use the setImageURI method of the ImageButton for both image resources and other 222
398. ork that will serve as pri mary teaching tool for the rest of the book You ll start by developing an animated splash screen followed by screens for main menu settings help and scores You ll 3 What Is and Isn t in This Book learn basic user interface design principles how to collect input from the user and how to display dialogs to the user Finally you ll implement the core application logic of the game screen gt Part III Enhancing Your Application with Powerful Android Features In Part III you ll dive deeper into the Android SDK adding more specialized features to the Been There Done That application You ll learn how to work with graphics and the built in camera how to leverage LBS how to network enable your applica tion and how to enhance your application with social features gt Part IV Adding Polish to Your Android Application In Part IV you ll learn how to customize your application for different handsets screen sizes and foreign languages You ll also learn about different ways to test mobile applications gt Part V Publishing Your Application In Part V you ll learn what you need to do to prepare for and publish your Android applications to the Android Market gt Part VI Appendixes In Part VI you ll find several helpful references for setting up your Android develop ment environment using the Eclipse IDE and accessing supplementary book materi als like the book websi
399. otect user data during transmission For example you can encrypt all data being sent over HTTP via SSL using HTTPS Passwords that have already been shared through a secured channel can be sent in hashed form using MessageDigest Q Is JavaScript Object Notation JSON support available on the Android plat form A Yes you can find JSON libraries in the org json package in the Android SDK Workshop Quiz 1 Which of the following can the TelephonyManager class provide information about A Call State B Network Type C UserName 2 True or False The Android SDK comes complete with full multi part MIME handling support 3 True or False Network operations should always be performed on the UI thread so they are as fast as possible 290 HOUR 16 Adding More Network Support 4 Which of the following are classes or objects that cannot be used to perform tasks in the background A BackgroundTask B AsyncTask C Thread D AsyncActivity Answers 1 A and B The TelephonyManager can provide Call State and Network Type information 2 False There is no built in MIME support Instead this hour demonstrates how to add external libraries that have MIME support 3 False Lengthy operations such as networking operations should never be performed on the UI thread to keep the handset as responsive as possible 4 A and D An AsyncTask is really a helper class that simplifies the use of a Thread Both classes can be us
400. other orientations provided that you tweak font and graphic sizes later Porting issues is discussed in a future chapter Implementing the Splash Screen Layout Now that you know how your splash screen should look you need to translate the rough design into the appropriate layout design Recall that the res layout splash xml layout file is used by QUizSplashActivity You need to update the default layout which simply displays a single TextView control informing us it is the splash screen to contain controls for each of the elements in the rough design Screen layout controls come in many forms Each control is a rectangle that can control a specific part of the screen You are using two common screen controls on your splash screen gt A TextView control displays a text string onscreen gt An ImageView control displays a graphic onscreen You also need some way to organize various View controls on the screen in an order ly fashion For this you use Layout controls For example LinearLayout allows placement of child views in a vertical or horizontal stack Implementing the Splash Screen Layout 115 In addition to LinearLayout there are a number of other Layout controls Layouts may be nested and control only part of the screen or they may control the entire screen It is quite common for a screen to be encapsulated in one large parent lay out often a LinearLayout control Table 7 1 lists the available Layout controls
401. ource file in Eclipse 14 HOUR 1 Getting Started with Android Editing the Android Manifest File The Android manifest file is the central configuration file for an Android applica tion The editor organizes the manifest information into a number of tabs gt Manifest This tab shown in Figure 1 3 is used for general application wide settings such as the package name and application version information used for installation and upgrade purposes Application This tab is used to define application details such as the name and icon the application displays as well as the guts of the application such as what activities can be run including the default launch DroidActivity and other functionality and services that the application provides Permissions This tab is used to define the application s permissions For example if the application requires the ability to read the contacts from the phone then it must register a Uses Permission tag within the manifest with the name android permission READ CONTACTS gt Instrumentation This tab is used for unit testing using the various instru mentation classes available within the Android SDK gt AndroidManifest xml This tab provides a simple XML editor to edit the manifest file directly If you switch to the AndroidManifest xml tab your manifest file will look something like this lt xm lt man lt ma l version 7 0 encoding utf 8 gt
402. ours to develop the framework for the favorite place feature This is a great way to exercise some of your new skills To implement the feature follow these steps 1 Add any new String Dimension Color or Drawable resources needed to support the layouts used by the feature 2 Update the res layout settings xml layout file to add the new region at the bottom of the settings screen for launching the favorite place dialog and displaying the favorite location if one is set as shown in Figure 14 5 238 FIGURE 14 5 The settings screen with the favorite place feature un ra 14 Adding Support for Location Based Services androidwirelessdev gmail com Password v Birth Date 4 Dec mber 08 1975 Genda Favorite Place 7 Olympic Natfonal Park 3 Add the res layout fav_place_dialog xml layout file to the project and implement the TextView EditText and Button controls the dialog requires as shown in Figure 14 6 4 Define three new game preference String values in the QuizActivity class These preferences will be used by the application s SharedPreferences to store the user s favorite location name String as well as that location s lati tude float and longitude float 5 Update the QuizSettingsActivity class to include a new dialog First define a dialog identifier for example PLACE_DIALOG_ID in the class Then update the onCreateDialog and onPrepareDialog methods
403. out 2009 more Android handsets and diverse types of devices powered by Android reached world markets As of this writing there are more than 36 Android phones available from carriers around the world This number does not include the numerous Android tablet and e book readers also available nor the dozens of upcoming devices already announced nor the consumer electronics run ning Android The rate of new Android devices reaching the world markets has con tinued to increase In the United States all major carriers now include Android phones in their product lines Google has been a contributing member of the Open Handset Alliance from the beginning The company hosts the Android open source project as well as the Android developer program at http developer android com This developer website is your go to site for downloading the Android SDK getting the latest platform docu mentation and browsing the Android developer forums Google also runs the most popular service for selling Android applications to end users the Android Market The Android mascot is the little green robot shown in Figure 1 1 Familiarizing Yourself with Eclipse The Android Developer Challenge Google has hosted several contests called Developer Challenges to encourage developers to write Android applications The first two rounds saw 10 million in prize money awarded Cheap and Easy Development If there s one time when cheap and easy is a
404. out_height attributes to fill_parent 8 Define the content of your tabs Within the FrameLayout control add two TableLayout controls one for each tab You will use these TableLayout con trols to display the scores Name the first TableLayout control TableLayout_AllScores and the second TableLayout_FriendScores Set the layout_width and layout_height attributes to fill_parent Set the stretchColumns attribute to to allow columns to resize based on the content When creating a tabbed view in this way you must name the identifier as listed above android id tabcontent otherwise exceptions will be thrown at run time This references a special Android package resource It is not the same as using id tabcontent That would create a new identifier for a layout object in your own application package You can make many controls scrollable by wrapping them within a ScrollView control For example to give a TableLayout control a vertical scrollbar wrap it in a ScrollView control and set the scrollbars attribute to vertical You also need to set its layout_width and layout_height attributes The TabHost section of the scores screen layout file with optional scrolling TableLayout tabs should look something like this lt TabHost android id id TabHost1 android layout_width fill_ parent android layout_height fill_parent gt lt LinearLayout android orientation vertical android layout_width fill_ parent androi
405. ow Android website 426 startActivity method 48 51 123 455 storing data startActivityForResult method 49 52 224 startAnimation method 122 starting progress dialog 272 progress indicators 268 services 317 318 startService method 317 state activity state callback methods 49 50 managing 49 saving 50 51 status network status checking 260 261 phone status information accessing retrieving telephony information 279 280 setting phone state permissions 278 stopping services 317 318 stopSelf method 317 stopSelfResult method 317 stopService method 318 storing data application resources 60 62 directories 358 files 358 overview 358 questions in hashtable 210 resources 74 SQLite databases 359 system resources 63 How can we make this index more useful Email us at indexes samspublishing com 456 strategies for internationalization strategies for internationalization T target SDK specifying 342 forgoing internationalization tasks 327 328 TabHost control asynchronous tasks full internationalization adding tabs to 155 running with AsyncTask 328 329 adding to scores screen 150 class 265 266 limited l _ configuring 155 running with threads and internationalization 328 setting default tab 155 handlers 266 eve i TableLayout control 115 managing WiN BOMS 30 accessing oe tabs See TabHost control tearDown method 376 adding to Been There Done tage t
406. peDrawable class 67 supported image formats 66 67 ImageSwitcher controls animating 207 initializing 206 updating 207 ImageUploadTask class 288 imports organizing 415 416 incoming calls to emulator simulating with DDMS 31 32 incoming SMS messages to emulator simulating with DDMS 33 How can we make this index more useful Email us at indexes samspublishing com 442 indeterminate progress indeterminate progress displaying with progress bars 263 inflate method 191 InformIT website 423 424 integrating Eclipse IDE with source control 421 initializing dialogs 183 186 ImageSwitcher control 206 TextSwitcher control 205 input forms designing 55 input methods 350 inputStreamToString method 147 insertScoreRow method 270 installing Android Plug in for Eclipse ADT 412 413 Android SDK 10 explained 411 Linux installations 412 Mac OS X installations 412 Windows installations 411 applications 390 391 Eclipse IDE 410 JDK Java Development Kit 410 Instrumentation tab manifest file 14 80 integration testing 370 lt intent filter gt tag 87 88 intents ACTION_CHOOSER 226 ACTION_IMAGE_CAPTURE 225 226 230 ACTION_VIEW 248 explained 51 launching map applications with 248 249 launching other applications with 52 53 passing information with 51 52 TAKE_AVATAR_CAMERA_ REQUEST 227 TAKE_AVATAR_GALLERY_ REQUEST 228 internationalization a
407. pecially named directory that includes the two letter language code provid ed in ISO 639 1 see http www loc gov standards iso639 2 php code_list php fol lowed by a dash then a lowercase r and finally the ISO 3166 1 alpha 2 region code see http www iso org iso country_codes iso_3166_code_lists english_country_ names_and_code_elements htm For example American English is en rUS British English is en rGB and Australian English is en rAU Let s look at an example of how this works If you wanted the Been There Done That application to support these three versions of English you could do the following 1 Create a strings xml resource file for each language Any strings you don t want to localize can be left in the default American English res values strings xml file 2 Save the British English strings xml resource file to the res values en rGB directory 3 Save the Australian English strings xml resource file to the res values en rAU directory To summarize you start with a default set of resources which should be in the most common language your application will rely on Then you add exceptions such as separate language and region string values where needed This way you can optimize your application so it runs on a variety of platforms For a more complete explanation of how the Android operating system resolves resources check out the Android developer website http developer android com gui
408. pecification Integration testing This testing ensures that the software integrates well with other core device features For example an application must suspend and resume properly and it must gracefully handle interruptions from the operating system for example incoming messages calls powering off Client server testing Networked mobile applications often have greater test ing requirements than stand alone applications This is because you must ver ify the server side functionality in addition to the mobile client Upgrade testing Android phones receive frequent firmware updates necessi tating application upgrades When possible perform application upgrade test ing of both the client and the server to ensure that any upgrades go smoothly for users Internationalization testing This testing ensures internationalization sup port especially language support early in the development process If an application is supporting multiple languages you re likely to run into some problems in this area related to screen real estate as well as issues such as date formatting Usability testing This testing identifies any areas of the application that lack visual appeal or are difficult to navigate or use It verifies that the appli cation s resource consumption model matches the target audience For exam ple gamers might accept shorter battery life for graphic intensive games but productivity applications should not drain t
409. pletes Specifically when you have completed all parsing and displaying you can hide the progress indicator shown in the title bar if all the tasks are complete as determined by mProgressCounter Override protected void onPostExecute Boolean result Log i DEBUG_TAG onPostExecute mProgressCounter if mProgressCounter lt 0 mProgressCounter Q QuizScoresActivity this setProgressBarIndeterminateVisibility false Handling Cancellation You can handle cancellation of the background processing by overriding the onCancelled method The onCancelled method runs on the UI thread and if it s called it means that the onPostExecute method will not be called Thus any cleanup must be performed here For this example we perform the following operation Override protected void onCancelled Log i DEBUG_TAG onCancelled mProgressCounter if mProgressCounter lt 0 Downloading and Parsing Question Batches 271 mProgressCounter Q QuizScoresActivity this setProgressBarIndeterminateVisibility false The onCancelled method is called when the cancel method of AsyncTask is called This does not happen automatically Instead good practice is to cancel tasks when they are no longer needed For the scores screen you ll want to cancel the tasks if they re still running when the user leaves the screen for any reason That is you cancel them in the onPause method of the Activit
410. ploring more advanced Android features Designing advanced user interfaces Working with multimedia Managing and sharing data Accessing underlying device hardware When you are becoming familiar with a new mobile platform it can be very helpful to know what is feasible and what is not This hour provides a crash course in some of the more advanced features of the Android SDK Specifically you will learn more about using core application features designing advanced user interfaces using multimedia manag ing storage and data and accessing the underlying device hardware Exploring More Core Android Features Twenty four hours is certainly not enough time to cover all the interesting and useful fea tures of the Android platform and Android SDK You ve already packed tons of features into the Been There Done That application over the course of this book In this hour you will learn about many of the advanced features of the Android platform Declaring and Enforcing Application Permissions As you know applications must register the appropriate permissions they require within the Android manifest file Applications can also declare and enforce their own custom per missions with the lt permission gt tag Each permission must be defined in the Android manifest file and can be applied to specific components notably an activity or a serv ice within the application You can also apply permissions at the method level 348 FIGURE 21 1
411. pplication names 92 currency 330 date time formatting 330 explained 321 322 languages choosing target languages 331 defined 321 locales Android Market support for 326 327 Android SDK support for 322 323 changing 324 choosing target locales 331 defined 321 determining 329 330 resources specifying default resources 325 language specific resources 325 region specific resources 326 strategies forgoing internationalization 327 328 full internationalization 328 329 limited internationalization 328 testing 370 troubleshooting 331 isNetworkRoaming method 280 lt item gt element 138 J K JAR files adding to projects 286 287 jarsigner utility 390 Java Development Kit JDK installing 410 java io package 358 JavaScript Object Notation JSON 289 javax xml package 72 JDK Java Development Kit installing 410 JSON JavaScript Object Notation 289 JUnit automated testing with adding more tests 379 380 creating test cases 375 377 creating test projects 374 375 explained 374 running automated tests 378 379 website 380 keystrokes EditText 169 170 keytool utility 390 L landscape mode creating custom layout for 335 337 languages Android Market support for 405 choosing target languages 331 defined 321 language specific resources specifying 325 last known location LBS 245 launch activity designating 87
412. pplications HTTP and HTTPS can be used for web technolo gies TCP and IP are lower level network protocols used by Android and there are standard Java APIs for direct network socket use Exercises 1 Test the Been There Done That application in a variety of network situations Modify the emulator settings to simulate a slow network and then run the application and view the results 2 Modify the application to use the Thread and Handler methods for back ground processing instead of the AsyncTask method 3 Modify the application to download the next batch of trivia questions in the background prior to running out of existing questions in the batch This page intentionally left blank HOUR 16 Adding More Network Support What You l Learn in This Hour gt Accessing device telephony information Using HTTP client services Performing HTTP GET requests Performing HTTP POST requests Adding third party JAR files to your project Working with multipart MIME files vv v v Vv In this hour you enhance the Been There Done That application to upload player data such as settings scores and avatars to the application server You also learn how to access information about the device s telephony status Finally you add some external libraries to an Android project and work with multipart MIME entities Determining Data to Send to the Server So far you have only downloaded data within the Been There Done That application
413. pplications but may also apply to other Java development in Eclipse Do you have your own tips or tricks for Android development in Eclipse If so email them to us with permission to publish them at androidwirelessdev gmail com and they may be included on our blog at http androidbook blogspot com Get your moment of geekly fame Creating New Classes and Methods You can quickly create a new class and corresponding source file by right clicking the package to create it and choosing New Class Then you enter the class name pick a superclass and interfaces and choose whether to create default comments and method stubs for the superclass for constructors or abstract methods Along these lines you can quickly create method stubs by right clicking a class or within a class in the editor and choosing Source Override Implement Methods Then you choose the methods to create stubs for where to create them and whether to generate default comment blocks Organizing Imports When referencing a class in your code for the first time you can hover over the newly used class name and choose Import Classname package name to have Eclipse quickly add the proper import statement In addition the Organize imports command Ctrl Shift O in Windows or Cmd Shift O on a Mac causes Eclipse to automatically organize your imports Eclipse removes unused imports and adds new ones for packages used but not already imported If there
414. py LEVEL 23 startActivity intent When the HelpActivity class launches the getIntent method can be used to retrieve the intent Then the extra information can be extracted using the appropri ate methods Here s an example 52 HOUR 3 Building Android Applications Intent callingIntent getIntent int helpLevel callingIntent getIntExtra com androidbook chippy LEVEL 1 This little piece of information could be used to give special Help hints based on the level For the parent activity that launched a subactivity using the startActivityForResult method the result will be passed in as a parameter to the onActivityResult method with an Intent parameter The intent data can then be extracted and used by the parent activity Using Intents to Launch Other Applications Initially an application may only be launching activity classes defined within its own package However with the appropriate permissions applications may also launch external activity classes in other applications There are well defined intent actions for many common user tasks For example you can create intent actions to initiate applications such as the following gt Launching the built in web browser and supplying a URL address gt Launching the web browser and supplying a search string gt Launching the built in Dialer application and supplying a phone number gt Launching the built in Maps application and supplying a location gt
415. r This allows you to have a reasonable identifier for the player even before he or she begins to enter other settings information It also makes it possible for the player to change other information such as his or her nickname without unforeseen consequences You should store the resulting identifier because it is used in all future requests When you have all the appropriate query variables set you are ready to generate the request You can use the handy URLEncodedUtils format method to format the vector of variables for the GET request Finally you initialize an HttpGet object Uploading Data to a Remote Application Server 285 pass the GET request string you formulated and execute it by using an HttpClient instance The HttpClient class provides helper utilities in the form of the ResponseHandler classes to parse the response In this case BasicReponseHandler is used to easily retrieve the body of the response as a String object In this case the String object contains the unique player ID which can be stored in SharedPreferences for future use It is typically not a good idea to send sensitive data across networks in plain text By For example the device identifier could be used for nefarious purposes Because ay all this application needs is some sort of unique but repeatable identifier you could use a one way hashing function such as Secure Hash Algorithm SHA to do secure the device identifier data The MessageDig
416. r application may be presented to the user in more cases than just when they launch it To learn how to incorporate global search functionality into Android applications By the see the documentation for SearchManager android app SearchManager and ay the Searchable Dictionary sample application found with the Android SDK 362 Oat ow HOUR 21 Diving Deeper into Android Accessing Underlying Device Hardware Android developers have unprecedented access to the underlying hardware on a device In addition to hardware such as the camera and LBS services the Android SDK has a variety of APIs for accessing low level hardware features on the handset including the following gt Reading raw sensor data such as the magnetic and orientation sensors gt Accessing Wi Fi and Bluetooth sensors gt Monitoring battery usage and power management Not all sensors and hardware are available on each Android device Many of these features are optional hardware The sensors available on a given device vary in terms of availability and sensitivity Some sensors provide raw sensor data while others are backed by services or soft ware to provide useful data to the application Reading Raw Sensor Data The following are some of the device sensors that the Android SDK supports gt Accelerometer Measures acceleration in three dimensions gt Light sensor Measures brightness which is useful for camera flashes g
417. r is that when pro cessing returns from the onUpdate method the App Widget process may go away destroying any running threads An Android Service instance won t go away though so you can use it to run background operations You can see all the services currently running on an Android handset or emulator by selecting Settings Applications Running Services From here you can choose to stop services as well Figure 18 3 shows the Running Services screen FIGURE 18 3 The Running Services Android keyboard 22M8 screen Process com androld inputmethod latin S Android keyboard Been There Done That Process com androldbook LHviatnjutz22 g QuizWidgetProvider Wi00 07 Na Started by applicat ch to ste on tou p Avail 27MB 26MB in 6 Other 26M8 in 3 Creating a Service A Service object is created by extending the Service class overriding three primary methods and defining the service within the AndroidManifest xm1 file For the Been There Done That App Widget you must define the Service object within QuizWidgetProvider Then you can move the bulk of the onUpdate code to the onStartCommand method of the Service object and create a Thread object to do the work so the App Widget and service are responsive 316 ow ow HOUR 18 Creating a Home Screen App Widget The life cycle of a Service is different from that of an Activity class Because the example here has been simplified you are no
418. raw file resource programmatically simply use the openRawResource method For example the following code would create an InputStream object to access to the resource file res raw file1 txt InputStream iFile getResources openRawResource R raw file7 All raw file resources must have unique names excluding the file suffix so file1 txt and file1 dat would conflict Summary 73 There are times when you might want to include files within your application but Dig you _ not have them compiled into application resources Android provides a special ows project directory called assets for this purpose This project directory resides at the same level as the res directory Any files included in this directory are includ ed as binary resources along with the application installation package and are not compiled into the application Uncompiled files called application assets are not accessible through the getResources method Instead you must use AssetManager to access files included in the assets directory Working with Other Types of Resources We have covered the most common types of resources you might need in an appli cation There are numerous other types of resources available as well These resource types may be used less often and may be more complex However they allow for very powerful applications Some of the other types of resources you can take advantage of include gt String arrays gt M
419. rces TABLE 4 5 XML Utility Packages Package Description android sax Framework to write standard SAX handlers android util Xml XML utilities including the XMLPullParser org xml sax Core SAX functionality see www saxproject org javax xml SAX and limited DOM Level 2 core support org w3c dom Interfaces for DOM Level 2 core org xmlpull XmlPullParser and XMLSerializer interfaces see www xmlpull org To access an XML file called res xm1 default_values xml programmatically you could use the getXm1 method like this XmlResourceParser defaultDataConfig getResources getXm1 R xml default_values Working with Raw Files An application can include raw files as resources Raw files your application might use include audio files video files and any other file formats you might need All raw resource files should be included in the res raw directory There are no rules or restrictions for formatting raw files aside from the resource filenames rules discussed earlier If you plan to include media file resources you should consult the Android platform documentation to determine what media for mats and encodings are supported on your application s target handsets The same goes for any other file format you want to include as an application resource If the file format you plan on using is not supported by the native Android system your application will be required to do all file processing internally To access a
420. re all the appro priate tools you need to get started developing Android applications gt The appropriate Java Development Kit JDK gt The Eclipse integrated development environment IDE gt The Android Software Development Kit SDK and tools gt Any drivers required by specific Android devices These software packages are available free of charge from their vendors websites Development Machine Prerequisites Android developers may use a number of different operating systems and software config urations This appendix walks you through the installation of the tools used in this book If you re installing from scratch you will want to choose the latest versions of the software packages required for development For a complete list of software and system requirements see the Android developer web site http developer android com sdk requirements html Supported Operating Systems Android applications can be written on the following operating systems gt Windows XP or later gt Mac OS X 10 5 8 or later x86 only gt Linux 410 Dw APPENDIX A Configuring Your Android Development Environment Available Space You need around 2GB of space to safely install all the tools you need to develop Android applications This includes installing the JDK the Eclipse IDE the Android SDK and the tools and plug ins Installing the Java Development Kit Android applications can be developed using Sun s JDK 5 or JD
421. reating project 10 11 debugging with DDMS 21 22 editing project resources AndroidManifest xml file 13 15 res files 15 16 string resources 16 launching on handset 22 23 launching with emulator 19 21 project files 12 13 help screens adding resources to 145 146 defining features of 98 99 designing 144 raw resource files 147 148 updating layout of 146 HelpActivity class 44 high level game features determining 96 history of Android 8 Home screen adding App Widgets to 312 313 explained 37 HTTP GET method 282 285 HTTP networking 261 262 HTTP POST method 286 288 HttpClient class 285 286 HttpGet class 281 282 i method Log class 54 icon attribute lt item gt element 138 icons adding to applications 84 id attribute lt item gt element 138 identifiers 302 identifying target handsets 371 image media 223 gallery 227 228 launching activities and han dling results 224 225 photo taking with camera 225 227 441 incoming SMS messages ImageButton controls handling events 222 223 setting images of 221 222 images avatars adding to settings screen layout 219 220 designing 217 219 bitmaps generating 229 saving 228 229 scaling 229 230 transformations 230 image media 223 gallery 227 228 launching activities and handling results 224 225 photo taking with camera 225 227 ImageButton controls 221 223 loading 67 SD card images 38 Sha
422. reen simultaneously in a timed sequence and after a delay Thus tweened animation is a perfect choice for your splash screen With tweened animation you create an animation sequence either programmati cally or by creating animation resources in the res anim directory Each anima tion sequence needs its own XML file but the animation may be applied to any number of View controls You can use the built in animations provided in the android R anim class Adding Animation Resources For your splash screen you need to create three custom animations in XML and save them to the res anim resource directory fade_in xml fade_in2 xml and custom_anim xml The first animation fade_in xml simply fades its target from an alpha value of 0 transparent to an alpha value of 1 opaque over the course of 2500 milliseconds or 2 5 seconds There is no built in animation editor in Eclipse The XML for the fade_in xml animation looks like this lt xml version 7 0 encoding utf 8 gt lt set xmlns android http schemas android com apk res android android shareInterpolator false gt lt alpha android fromAlpha 0 0 android toAlpha 7 0 android duration 2500 gt lt alpha gt lt set gt You can apply this animation to the top TextView control with your title text Next you create the fade_in2 xm1 animation This animation does exactly the same thing as the fade_in animation except that you set the startO
423. remote URL imageUrl new URL getQuestionImageUrl1 questionNumber Bitmap bitmap BitmapFactory decodeStream imageUrl openStream image new BitmapDrawable bitmap catch Exception e Log e DEBUG_TAG Decoding Bitmap stream failed image getResources getDrawable R drawable noquestion return image Working with ViewSwitcher Controls The getQuestionImageUr1 method is a simple helper method that retrieves the appropriate graphic web address for a given question This information is stored in the Hashtable of questions We ll talk more about how we handle ques tions in a moment For the full implementation of the getQuestionImageUr1 method see the code provided with this book You use the URL class to encapsulate the remote address to the PNG image file you want to load into ImageSwitcher You then dump the data into BitmapDrawab1e Finally using the stream methods requires the android per mission INTERNET permission which needs to be added to the Android manifest file for the project Updating ImageSwitcher When you want to update ImageSwitcher with a new ImageView control you call the setImageDrawable method ImageSwitcher questionImageSwitcher ImageSwitcher findViewById R id ImageSwitcher_QuestionImage Drawable image getQuestionImageDrawable nextQuestionNumber questionImageSwitcher setImageDrawable image Calling the setImageDrawable method causes My
424. reproduc tion phones gt Testing difficult or dangerous scenarios that are not feasible or recommended on live handsets such as tests that might somehow break a phone or invali date a service agreement Maximizing Test Coverage The emulator provides a useful but limited simulation of a generic Android device By using AVD configuration options you can customize an emulator to closely rep resent a target handset However an emulator does not rely on the same hard ware or software implementation that will be found on an actual handset An emulator simply pretends The more hardware features an application relies on for example making calls networking LBS the camera Bluetooth the more important it is to test on an actual device Testing on Target Handsets Here is a mobile mantra that is worth repeating Test early test often test on the actu al device It s important to get target handsets in hand as soon as you can This cannot be said enough Testing on the emulator is helpful but testing on the handset is essential In reality it doesn t really matter if your application works on the emulator users run the applications on handsets It s important to test application assumptions early and often on the target hand set s This is called feasibility testing It is disheartening to design and develop an application and then find that it doesn t work on the actual handset Just because yo
425. riteria are reached mo oO gt All of the above 3 True or False Automated testing for Android applications can be performed only on the emulator 4 The JUnit framework included with Android can be used for testing many things Which of the following can it not do A Run repeated tests all day long without tiring B Test on old devices C Move the handset around the country to test GPS signals D Test behavior on multiple carriers operators Answers 1 True The Android SDK includes a variety of packages for developing test suites for automated application testing 2 F These are all defects of different kinds performance integration interna tionalization usability and functional defects A An application that takes too long to start up is a serious performance issue that may cause the Android operating system to kill the app which is not good B Most Android devices are phones first an application must interact well with the rest of the system which means gracefully handling incoming calls and text messages C A well written application does not short change users in foreign languages by 382 HOUR 22 Testing Android Applications providing a substandard user interface D A well done user interface is essen tial to the success of an application E A functional defect that is a prob lem with the core application logic is always a defect no matter how unlike ly the event False Autom
426. rk operations and protocols Developers can secure network communication by using common technologies such as SSL and HTTPS To access a network an Android application must have the appropriate permissions granted within the Android manifest file Network tasks are blocking operations and mobile networks can be very slow so it is imperative that all network opera tions be handled asynchronously Network operations can take some time Therefore all network related calls should be handled asynchronously separately from the main UI thread This can be accomplished by using the Java Thread class or by using the Android AsyncTask class which is discussed later in this hour Setting Network Permissions To access network services on an Android device you must have the appropriate permissions An Android application can use most networking services only if it is granted the appropriate lt uses permission gt settings configured in the Android manifest file The following are some common permission values used by applications leveraging the network gt android permission INTERNET gt android permission ACCESS NETWORK_STATE There are a number of other permissions related to networking including those that allow access and changes to Wi Fi state and network state You might also want to look at android permission WAKE_LOCK to keep the device from sleeping Checking Network Status The Android SDK provides utilities for
427. rmation about an application package This method returns a PackageInfo object which contains all the information of that application s manifest file from configuration details to the list of specific activities and per missions of the application Workshop 393 Workshop Quiz 1 True or False The release process is important only for big projects 2 Which version fields in the application s Android manifest file should you ver ify for release purposes A android versionCode B android versionLabel C android versionName D android version E All of the above 3 True or False You cannot publish an application that includes a debug signature Answers 1 False Whether you re a hobbyist working on your own or a member of a large development team taking the time to verify whether an application is ready for release is important to the success of the application 2 A and C The Android platform uses the version code to perform upgrades and the version name is a string field that developers and markets use for product support purposes 3 True The Android package manager installs only applications that have been properly signed Exercises 1 Choose one of the Been There Done That builds from this book from any hour Export the APK package file and digitally sign it 2 Install the Been There Done That application package on a handset by using the adb command line utility This page intentionally le
428. rnationalization gt Forgo internationalization entirely gt Limit internationalization gt Implement full internationalization for target audiences Now let s talk about each of these strategies in more detail Forgoing Application Internationalization Whenever possible save your development and testing teams a lot of work don t bother to internationalize your application This is the one size fits most approach to mobile development and it is often possible with games and other simple graphic intensive applications If your application simple enough to work smoothly with internationally recognized graphical icons such as play pause stop and so on instead of text labels or Sims language garbled mumbles that get the point across to speakers of any language then you may be able to forgo internationaliza tion entirely However this works only for a subset of applications If your applica tion requires a help screen for example you re likely going to need at least some localization for your application to work well all over the world Some of the pros of this strategy are the following 328 HOUR 19 Internationalizing Your Application gt Simplified development and testing gt Smallest application size only one set of resources Some of the cons of this strategy are the following gt For text or culture dependant applications this approach greatly reduces the value of the application It is
429. roid Development Division Organization Stark Enterprises City or Locality Los Angeles State or Province California Country Code XX US The Android team recommends that you use a key validity of 25 years or more In Watch fact the Android Market will reject any application with a key that is not valid until ut at least October 22 2033 so 25 years covers this requirement as well 390 Diktow HOUR 23 Getting Ready to Publish 8 Click the Next button 9 On the Enter destination and key certificate checks screen enter a destina tion for the application package file 10 Click the Finish button You have now created a fully signed and certified application package file You can also use the keytool and jarsigner applications available within the JDK in addition to the zipalign utility provided with the Android SDK to create a suitable key and sign an application package file apk Although zipalign is not directly related to signing it optimizes the package for more efficient use on Android The ADT plug in for Eclipse runs zipalign automatically after the signing step Testing the Signed Application Package Now that you have signed and packaged an application and now that it s ready for production you should perform one last test cycle paying special attention to subtle changes to the installation process for signed applications Installing the
430. roidManifest xml file lt receiver android name QuizWidgetProvider gt lt intent filter gt lt action android name android appwidget action APPWIDGET_UPDATE gt lt intent filter gt lt meta data android name android appwidget provider android resource xml widget_info gt lt receiver gt This lt receiver gt segment of the Android manifest file defines an intent filter for App Widget updates In addition it ties the App Widget and its definition file to the overall application 308 HOUR 18 Creating a Home Screen App Widget Designing the App Widget Layout App Widgets have specific layout requirements To begin with an App Widget is drawn through the RemoteViews interface which limits the user interface that can be displayed Next the App Widget must conform to the size configured in its proper ties A RemoteViews object is used when the actual display of a view will be performed from within another process This is exactly what happens with an App Widget It is displayed in the App Widget host process not the application s main process RemoteViews objects are limited in the layout and view objects they may use Some layout and view objects supported within App Widgets include the following gt LinearLayout gt FrameLayout gt RelativeLayout gt TextView gt ImageView gt Button gt ImageButton gt ProgressBar gt AnalogClock gt Chronometer Classes extending these con
431. rol This is a perfect time to try out RelativeLayout which allows each child view to be placed in relation to the parent layout or other child view controls Therefore you can easily describe the header as a RelativeLayout control with three child layouts gt An ImageView control aligned to the top left of the parent control gt A TextView control aligned to the top center of the parent control gt An ImageView control aligned to the top right of the parent control Adding the ListView Control Next in your layout you include the ListView control A ListView control is simply a container that holds a list of View objects The default is for a ListView control to contain TextView controls but ListView controls may contain many different View controls A ListView control of TextView controls works fine for this example To override the default behavior of each child TextView you need to make a layout resource to act as the template for each TextView control in the ListView control Also you can make the menu more interesting by adding a custom divider and selector to the ListView control 130 FIGURE 8 2 Layout design for the Been There Done That main menu screen HOUR 8 Implementing the Main Menu Screen Finishing Touches for the Main Menu Layout You finish off the layout by adding the ImageView control after the ListView con trol As before you need to wrap your screen in a vertically oriented LinearLayout contro
432. rol and set its id attribute to EditText_Pwd2 its maxLines attribute to 1 and its inputType attribute to textPassword 5 Finally add a TextView control with the id attribute TextView_PwdProblem to display the password status label text This TextView control will display whether the two password fields match At this point save the password_dialog xml layout file Adding the Password Dialog to the QuizSettingsActivity Class To create a custom AlertDialog you must first declare a unique identifier to repre sent the dialog as follows static final int PASSWORD _DIALOG_ID 1 Next you need to update the onCreateDialog method of QuizSettingsActivity to include a case statement for the new Dialog identifier case PASSWORD_DIALOG_ID Build Dialog Return Dialog Now let s look at how to build the password dialog from the ground up You begin by inflating loading the layout you created into a View control Working with Custom Dialogs 191 LayoutInflater inflater LayoutInflater getSystemService Context LAYOUT_INFLATER_SERVICE final View layout inflater inflate R layout password_dialog ViewGroup findViewById R id root To load the password_dialog xml layout file into a view you must retrieve LayoutInflater and then call the inflate method passing in the layout resource identifier as well as the root layout control s identifier in this case the LinearLayout encapsulating the Dialog controls cal
433. rovide an implementation of the onDateSet method to handle when the user chooses a spe cific date of birth and save it to the SharedPreferences DatePickerDialog dateDialog new DatePickerDialog this new DatePickerDialog OnDateSetListener public void onDateSet DatePicker view int year int monthOfYear int dayOfMonth Time dateOfBirth new Time dateOfBirth set dayOfMonth monthOfYear year long dtDob dateOfBirth toMillis true dob setText DateFormat format MMMM dd yyyy dtDob Editor editor mGameSettings edit editor putLong GAME_PREFERENCES_DOB dtDob editor commit J s 0 0 0 A DatePicker control has three different input controls month day and year Therefore to create DatePickerDialog you must set these date fields individually Because DatePickerDialog can be launched any number of times you do not ini tialize its date within the onCreateDialog method but instead pass in default val ues three zeros Finally you return the new DatePickerDialog you created in the onCreateDialog method switch statement return dateDialog Initializing DatePickerDialog You want to initialize DatePickerDialog each and every time it is displayed so you override the onPrepareDialog method to set DatePicker to either today s date or the birth date saved in the game preferences You can use the Calendar class to get the current date on the device The Calendar class has fields for each of
434. roy Log d DEBUG_TAG SHARED PREFERENCES Log d DEBUG_TAG Nickname is mGameSettings getString GAME_PREFERENCES_ NICKNAME Not set Log d DEBUG_TAG Email is mGameSettings getString GAME_PREFERENCES EMAIL Not set Log d DEBUG_TAG Gender M 1 F 2 U 0 is mGameSettings getInt GAME_PREFERENCES_GENDER 0 We are not saving the password yet Log d DEBUG_TAG Password is mGameSettings getString GAME_PREFERENCES_ PASSWORD Not set We are not saving the date of birth yet Log d DEBUG_TAG DOB is DateFormat format MMMM dd yyyy mGameSettings getLong 178 HOUR 10 Building Forms to Collect User Input GAME_PREFERENCES_DOB 0 super onDestroy Now whenever QuizSettingsActivity is destroyed for example when a user presses the Back button the preferences that have been committed are displayed in the LogCat console Summary In this hour you added a form to the settings screen of the Been There Done That trivia application The form handles various fields including text input of various kinds using EditText controls and a drop down list using a Spinner control You also conserved screen space by implementing two Button controls which can be wired up in the future to launch Dialog windows Finally you implemented a sim ple SharedPreferences mechanism to load and save game settings for use in the application Q amp A Q Why not use the typical Save and Ca
435. s 316 317 starting stopping services 317 318 controls 318 event handling 313 314 explained 305 306 layout 308 methods 309 multiple instances of 319 properties 306 307 RemoteViews object 311 429 applications application assets compared to project resource 74 definition of 73 application contexts accessing application functionality 47 accessing application preferences 46 47 launching activities with 48 retrieving application resources 46 retrieving context for current process 46 Application Manager 109 application resources definition of 59 referencing 62 storing 60 62 application servers 256 257 application sliding drawer 37 Application tab manifest file 14 78 79 lt application gt tag android debuggable attribute 85 android description attribute 85 android icon attribute 84 android label attribute 84 applications activities callback methods 49 50 explained 47 launching 48 49 managing state 49 saving state 50 51 How can we make this index more useful Email us at indexes samspublishing com 430 applications application assets compared to project resource 74 definition of 73 application contexts accessing application functionality 47 accessing application preferences 46 47 retrieving application resources 46 retrieving context for current process 46 application information logging 374 application resources
436. s 420 findViewByld method 54 147 155 171 173 191 finish method 51 firmware troubleshooting 343 folders See directories forgoing internationalization 327 328 format method 187 formatting code 418 strings 64 XML files 71 forms Button controls configuring 170 171 handling button clicks 171 172 EditText controls committing EditText input 169 configuring 168 handling text input 168 listening for EditText key strokes 169 170 input forms 55 saving form data with SharedPreferences defining SharedPreferences entries 175 reading settings from 177 178 saving settings to 176 439 functional testing settings screens adding resources to 165 166 designing 161 163 updating layout of 166 167 Spinner controls 172 configuring 173 handling Spinner selections 173 174 listening for selection events 174 frame by frame animation 119 FrameLayout control 115 Friend Request dialog 296 friend requests enabling AsyncTask class 297 298 Friend Request dialog 296 settings screen layout 293 295 friend support enabling friend requests AsyncTask class 297 298 Friend Request dialog 296 settings screen layout 293 295 explained 292 293 friends scores displaying 298 FriendRequesttTask class 296 297 fromFile method 228 full internationalization 328 329 functional testing 370 index more useful Email us at indexes samspublishing com
437. s However you now have a framework to build on In the next few hours you will flesh out the different screens and begin to implement game functionality BMS 9 30 pm B e gt amp Alarm Clock BeenThere Browser fer fal liste Done That G ws Camera Contacts Custom Dev Tools Locale i amp Gallery Maps Messaging s amp s Me Summary 109 Exploring the Prototype Installation The Been There Done That application does very little so far but you can use tools on the Android emulator to peek at all you ve done so far gt Application Manager This is helpful for determining interesting informa tion about an application In the emulator navigate to the home screen click the Menu button and choose Settings Applications Manage Applications and then choose the Been There Done That item from the list of applications Here you can see some basic information about the application including storage and permissions used as well as information about the cache and so on gt Dev Tools This tool helps you inspect the application in more detail In the emulator pull up the application drawer launch the Dev Tools application and choose Package Browser Navigate to the package name com androidbook triviaquiz This tool reads information out of the manifest and allows you to inspect the settings of each activity registered Of course you can also begin to investigate the application by using t
438. s You can use the TTS engine to have your appli cations read text to the user You may have seen this feature used frequently with Location Based Services LBS applications that allow for hands free directions Other applications use this feature for users who have reading or sight problems The Android TTS engine supports a variety of languages including English in American or British accents French German Italian and Spanish The synthesized speech can be played immediately or saved to an audio file which can be treated like any other audio file To provide TTS services to users an Android device must have both the TTS engine available in Android SDK 1 6 and higher and the appropriate language resource files In some cases the user must install the appropriate language resource files assuming that the user has space for them from a remote loca tion The users can do this themselves by going to Settings Text to speech Install Voice Data You may also need to do this on your devices Additionally the appli cation can verify that the data is installed correctly or trigger the installation if it s not See the documentation for the android speech tts package Working with Multimedia Converting Speech to Text You can enhance an application with speech recognition support by using the speech recognition framework android speech RecognizerIntent You use this intent to record speech and send it to a rec
439. s such as rectangles and ovals See the Android documentation for the android graphics drawable package for further information Working with Layouts Most Android application user interfaces are defined using specially formatted XML files called layouts Layout resource files are included in the res layout directory You compile layout files into your application as you would any other resources Layout files often define an entire screen and are associated with a specific activi Did you__ ty but they need not be Layout resources can also define part of a screen and ow can be included within another layout 68 ow HOUR 4 Managing Application Resources Here is an example of a layout resource file lt xml version 7 0 encoding utf 8 gt lt LinearLayout xmlns android http schemas android com apk res android android orientation vertical android layout_width fill_ parent android layout_height fill_parent gt lt TextView android layout_width fill_ parent android layout_height wrap_content android text string hello gt lt LinearLayout gt You might recognize this layout It is the default layout called main xml created with any new Android application This layout file describes the user interface of the only activity within the application It contains a LinearLayout control that is used as a container for all other user interface controls in this case a single TextView control
440. s a draft which is great for verification before final publish ing Also the application icon name version localization information and required permissions are shown so you can verify that you have configured the Android Manifest file properly Publishing on the Android Market After you click the Publish button the application appears in the Android Market almost immediately Once your app is published you can see statistics including ratings reviews downloads active installs and so on in the Your Android Market Listings section of the main page on your developer account These statistics aren t updated as frequently as the publish action and you can t see review details directly from the listing By clicking the application listing you can edit the various fields Although some details can be edited pricing information can t be changed For example if your app starts as a free application it will remain that way You can always upload a different version for a paid version of the application with new features Paid Selling on the Android Market 401 application pricing can be changed at any time but must fall within certain limits In USD this is from 99 cents to 200 but it varies depending on the currency in use Understanding Billing Unlike some other mobile platforms you may have used Android does not currently provide built in billing APIs that work directly from within applications or charge dire
441. s in dp as opposed to px gt Add custom alternative resources when needed but sparingly By making these changes to the Been There Done That project we see that the application now displays properly on a wider variety of devices including the Motorola Droid Supporting Different Handset Features As you saw in Table 20 1 developers can provide custom resource files for a number of different handset configuration situations A game might customize certain resources if the handset has no hardware keyboard or if the handset has a specific type of touch screen or navigation pad Graphics files may be enlarged for very capable handsets with high resolution screens whereas on basic handsets they may be reduced to save space In extreme cases a game may be 2D on one handset and 3D on another Developing for Different Android SDKs At the time of this writing there are six different versions of the Android SDK in users hands Android 1 1 Android 1 5 Android 1 6 Android 2 0 Android 2 0 1 and Android 2 1 The upcoming releases codenamed Froyo and Gingerbread will add to this list From time to time Google publishes a breakdown of the usage of various Android versions on handsets gt 0 1 of users are using Android SDK 1 1 gt 38 0 of users are using Android SDK 1 5 gt 31 6 of users are using Android SDK 1 6 Vv 0 3 of users are using Android SDK 2 0 gt 2 7 of users are using Android SDK 2 0 1 gt 27 3
442. s many unique challenges to testers especially in terms of configuration management Identifying and Acquiring Target Handsets The earlier you can decide on and get your hands on the target handsets the better Sometimes this is as easy as going to the store and grabbing a new phone with a new service plan other times it s more complicated Some companies run developer programs with phone labs Here developers can Dig you rent time on specific handsets by mail remotely via the Internet or by traveling ow to the lab This gives developers access to a wide variety of handsets on many different networks without requiring them to own each and every one Some labs are even staffed with experts to help iron out handset specific problems For preproduction handsets it can take months to get the hardware in hand from the manufacturer or operator through developer program loaner services Cooperating with carrier handset loaner programs and buying handsets from retail locations is frustrating but sometimes necessary Don t wait until the last minute to gather the test hardware you need There is no guarantee that a preproduction handset will behave exactly the same Watch as the production model that eventually ships to consumers Features are often ut cut at the last minute to make the production deadline Dealing with Device Fragmentation One of the biggest challenges a mobile application tester faces
443. s not display TabHost controls properly in design mode To design this kind of layout you should stick to the XML layout mode You must use the Android emulator or an Android device to view the tabs 1 Remove all the old controls as you have done for other layouts in this book 2 Adda new LinearLayout control setting its android background attribute to drawable bkgrnd All subsequent controls will be added inside this LinearLayout control 3 Add the same header you created in other layouts It should contain of a RelativeLayout control with two ImageView controls and a TextView con trol Set the TextView control s text attribute to the string resource string scores to reflect the appropriate screen title Implementing the Scores Screen Layout 4 Outside the RelativeLayout control but still within the LinearLayout adda TabHost control called TabHost1 Set its layout_width and layout_height attributes to fill_parent 5 Inside the TabHost control add another LinearLayout control with its orientation attribute set to vertical Set its layout_width and layout_height attributes to fill_parent 6 Inside the inner LinearLayout control add a TabWidget control Set the con trol s id attribute to android id tabs 7 Within the inner LinearLayout control at the same level as the TabWidget control add a FrameLayout control Set the FrameLayout control s id attribute to android id tabcontent and its layout_width and lay
444. s rely on soft keyboard support Q Is testing your application on the emulator alone sufficient A No The Android emulator simulates the functionality of a real device and can be a big time and cost saving tool for Android projects It is a convenient tool for testing but it can only pretend at real device behavior The emulator can not actually determine your real location or make a phone call Also the emulator is a generic device and does not attempt to simulate any quirky details of a specific handset Just because your application runs fine on the emulator does not guarantee that it will work on the device Workshop Quiz 1 Which features are available in the DDMS perspective A Taking screenshots of emulator and handset screens B Browsing the file system of the emulator or handset C Monitoring thread and heap information on the Android system D Stopping processes Simulating incoming phone calls and SMS messages to emulators All of the above Workshop 2 True or False You must use the Android emulator for debugging 3 Which target platforms can Android applications be written for 4 True or False The Android emulator is a generic device that supports only one screen configuration Answers 1 F All of the above The DDMS perspective can be used to monitor browse and interact with emulators and handsets in a variety of ways 2 False The Android emulator is useful for debugging but you can also connec
445. s to support map overlays drawing on top of the map gt Classes for working with position projections and handling other common LBS related tasks For some Google APIs and features you must sign up for a special account agree to further terms of service and receive an API key to use those services These features are exciting and powerful but they are unfortunately beyond the scope of this book Once you have mastered the basics of Android LBS support consider consulting a more advanced Android manual such as our book Android Wireless Application Development Addison Wesley Developer s Library which contains extensive exam ples using the Google APIs You can read more about these classes at the Google APIs Add On Reference website http code google com android add ons google apis reference index html Summary In this hour you implemented a new favorite place feature on the Been There Done That settings screen In this hour you learned how to use built in location based services to determine the current location as well as how to translate addresses into geographical coordinates You also learned how to launch the Maps application and view a specific location Finally you learned about some of the advanced features of the location based services functionality available within the Android SDK Q amp A Q want to use the MapView control Where do I get a Google API key A Start at the Google API add ons website which lis
446. s when the user lifts up from the touch screen as part of a single tap event onSingleTapConf irmed Called when a single tap event occurs onDoubleTap Called when a double tap event occurs onDoubleTapEvent Called when an event within a double tap gesture occurs including any down move or up action 352 Oat HOUR 21 Diving Deeper into Android gt onLongPress Similar to onSingleTapUp but called if the user has held his or her finger down just long enough to not be a standard click but also didn t move the finger gt onScrol1l Called after the user has pressed and then moved his or her finger in a steady motion and lifted up gt onFling Called after the user has pressed and then moved his or her finger in an accelerating motion just before lifting it In addition the android gesture package allows an application to recognize arbi trary gestures as well as store load and draw them This means almost any symbol a user can draw could be turned into a gesture with a specific meaning Some ver sions of the SDK have a Gesture Builder application that can simplify the process of creating gestures for applications that don t have a gesture recording feature For more information about the android gesture package see http developer android com resources articles gestures html Converting Text to Speech The Android platform includes a TTS engine android speech tts that allows devices to perform speech synthesi
447. sbens as wel as FAQS 9 glossary of lemma and other wlormanon The teat wep progamreg te Andad dowrlaadiny the SOK s0ware Seveleoment ir For unitrachom and wiloireanon abou the kt go to the SOK tab abo After you hae the SOK tegn by locking over the Dev Guide if you want to stat by geting a quick isok at the code the short Hato Stahl pania ats you Manag y ssn Vin Weft aphcaten 20 wmd bo when fr the Anton perm The Flundamentats Cocumert rs a good place to star for an understanding of he arpic atien amemo For as tcnal hep conde jorung one o mare of the Androd decussion groups Go te the Community pages lor more miotmaben To return to ths 5 past chch the Dev Gude tad misia amy Dev Gude Debugging Applications with DDMS 29 Now is a good time to get to know your way around the Android SDK documen tation First try the local documentation and then check out the online documentation Debugging Applications with DDMS The Dalvik Debug Monitor Service DDMS is a debugging utility that is integrated into Eclipse through the DDMS perspective The DDMS perspective provides a num ber of useful features for interacting with emulators and handsets see Figure 2 2 FIGURE 2 2 The DDMS per z on Js A Mirea G hesp Accation Tracker fe Dopico spective with A s a T A r ee one emulator and one Android device connected VanaavO 21 ceog __ 89000 tr The features of DDMS are roughly divided into five functiona
448. screen 102 FIGURE 6 7 The Been There Done That game screen 6 Designing an Application Framework Figure 6 7 shows a mockup of the game screen Have you evef climbed a mountain 9 l BS t Implementing an Application Prototype Now that you have a rough idea what the Been There Done That application will do and how it will look it s time to start coding This involves the following steps 1 Creating a new Android project in Eclipse 2 Adding some project resources including strings and graphics 3 Creating a layout for each screen 4 Implementing an activity for each screen 5 Creating a set of application wide preferences The code for this project is available on the book website http www informit com title 9780321673350 Implementing an Application Prototype Creating a New Android Project You can begin creating a new Android project for your application by using the Eclipse Android project wizard The project has the following settings gt Project name TriviaQuiz gt Build target Android 2 1 Google APIs gt Application name Been There Done That gt Package name com androidbook triviaquiz gt Create activity QUizSplashActivity Using these settings you can create the basic Android project However you need to make a few adjustments In the code provided with this book available at http www informit com title 9780321673350 th
449. se 47 Working with Tite nt oiin EE AA E RR a DI Working with DId logs assassiner O e Logging Application Information eee 54 Summary sidecases r E AN AEE EE E EESTE QQA oiii PE ETNE E E E T 55 WOEKSHOD So ssscssssssscnedssnscanecasstecaqenstsengsnsanasgangtnaassbetsesasssncagecassscenstsalonssasestnsasnnsuongsedbsasepasestasgstncncntat 56 vi Teach Yourself Android Application Development in 24 Hours HOUR 4 Managing Application Resources 59 Using Application and System Resources 59 Working with Simple Resource Values 63 Working with Drawable Resources 66 Working with Layouts 67 Working with Files 71 Working with Other Types of Resources 73 Summary 73 Q amp A 74 HOUR S Kuring the Android Manifest File E 77 Exploring the Android Manifest File 77 Configuring Basic Application Settings 81 Defining Activities 86 Managing Application Permissions 88 Managing Other Application Settings 91 Summary 91 Q amp A 92 Hour e Dasening an Application Framework a 95 Designing an Android Trivia Game 95 Implementing an Application Prototype 102 Running the Game Prototype 107 Summary 109 Q amp A 110 Workshop 110 vii Contents Part Il Building an Application Framework HOUR 7 Implementing an Animated Splash Screen 113 Designing the Splash Screen 113 Implementing the Splash Screen Layout 114 Working with Animation ee reece rate A EEFE LAD Summary 123 Q amp A 124 HOUR amp Implementing the Main Menu Screen d 127
450. se the App Widget isn t displayed in the same process as the application a new method is needed for getting the click event The Android SDK provides an 313 FIGURE 18 2 The Been There Done That App Widget 314 ow HOUR 18 Creating a Home Screen App Widget Intent type known as PendingIntent for this purpose This is an Intent that will basi cally be sent at a future time and can be sent by another process To create a PendingIntent an Intent instance must first be created Then the PendingIntent is created with some additional information such as what to do on subsequent uses of the same Intent That is the exact same instance could be used or a new instance could be created Once the PendingIntent object is created it can be assigned to the RemoteViews object via a call to the setOnClickPendingIntent method You need to add the code for this must before the call to the updateAppWidget method Intent launchAppIntent new Intent context QuizMenuActivity class PendingIntent launchAppPendingIntent PendingIntent getActivity context 0 launchAppIntent PendingIntent FLAG_UPDATE_CURRENT remoteView setOnClickPendingIntent R id widget_view launchAppPendingIntent The view identifier that the PendingIntent is added to via the call to the setOnClickPendingIntent method is the RelativeLayout object from the widget xml layout file Now when the App Widget is clicked QuizMenuActivity is launched this happens to
451. se true Save the manifest file If you switch to the AndroidManifest xml tab and look through the XML you will notice that the application tag now has the debuggab1le attribute android debuggable true A Editing Other Resource Files Most Android application resources are stored under the res subdirectory of the project The following subdirectories are also available gt drawable ldpi drawable hdpi drawable mdpi These subdirectories store graphics and drawable resource files for different screen densities and resolutions If you browse through these directories using the Eclipse Project Explorer you will find the icon png graphics file in each one this is your application s icon You ll learn more about the difference between these direc tories in Hour 20 Developing for Different Devices layout This subdirectory stores user interface layout files Within this subdi rectory you will find the main xml screen layout file that defines the user interface for the default activity 16 HOUR 1 Getting Started with Android gt values tThis subdirectory organizes the various types of resources such as text strings color values and other primitive types Here you find the strings xml resource file which contains all the resource strings used by the application If you double click on any of resource files the resource editor will launch Remember you can always edit the XML directly
452. seful It summarizes all the tests run and how long each one takes and it includes a stack trace for any failures found Figure 22 4 shows what this looks like in Eclipse Maximizing Test Coverage 379 FIGURE 22 4 Eclipse JUnit view running Android tests zi veto E Reler inished after 10 82 seconds 7 kai Rung 4 4 a Eros 0 a Failures 0 i comandeoidbook triviequiz22 tes QuickTest ver Aiit 3 0 506 s Failure Trace F 4 E comandroidbook triviaquiz22 test QuzSettingsActivityTests A testNidnamefieldConsistency 3 575 5 i testUpdateNiciname 7 026 s The second way of running the tests is available only in the emulator To use this method launch the Dev Tools app and then choose Instrumentation If you ve fol lowed along and don t have any other tests installed you ll likely see android test InstrumentationTestRunner as the only item shown Clicking this launches the tests When you use this method the only way to see results other than a visual indication during user interface tests is to watch the LogCat output The description of the item in the list can be changed In the AndroidManifest xml file of the test app in the instrumentation section modify it to read as follows lt instrumentation android targetPackage com androidbook triviaquiz22 android name android test InstrumentationTestRunner android label TriviaQuiz22 Tests gt Now when you launch Dev Tools and
453. simply too generic gt This strategy automatically alienates certain audiences and limits your appli cation s potential marketplaces Limiting Application Internationalization Most applications require only some light internationalization This often means internationalizing string resources only but other resources such as layouts and graphics remain the same for all languages and locales Some of the pros of this strategy are the following gt Modest development and testing requirements gt Streamlined application size specialized resources kept to a minimum Some of the cons of this strategy are the following gt Application may still be too generic for certain types of applications Overall design especially screen design may suffer from needing to support multiple target languages For example text fields might need to be large enough to support verbose languages such as German but look odd and waste valuable screen real estate in less verbose languages gt Because you ve headed down the road of providing language specific resources your users are more likely to expect other languages you haven t supported In other words you re more likely to start getting requests for your app to support more languages if you ve supported some That said you ve already built and tested your application on a variety of languages so adding new ones should be straightforward Implementing Full Application Internation
454. sm for simple tasks helps keep the number of Activity classes in an application manageable 182 FIGURE 11 1 The different Dialog window types available in Android HOUR 11 Using Dialogs to Collect User Input Exploring the Different Types of Dialog Windows There are a number of different Dialog window types available in the Android SDK including the following gt Dialog The basic class for all Dialog types see Figure 11 1a gt AlertDialog A dialog with one two or three Button controls see Figure 11 1b gt CharacterPickerDialog A dialog for choosing an accented character associ ated with a base character see Figure 11 1c gt DatePickerDialog A dialog with a DatePicker control see Figure 11 1d gt ProgressDialog A dialog with a determinate or indeterminate ProgressBar control see Figure 11 1e gt TimePickerDialog A dialog with a TimePicker control see Figure 11 1f A alog with a Title Tuesday April 12 1977 Set Cancel An Alert Dialog An Alert Message Insert character A Progress Dialog 11 59 PM be Set Cancel L s d If none of the existing Dialog window types is adequate you can create custom Dialog windows that meet your specific layout requirements We will discuss custom Dialog windows later in this hour Tracing the Life Cycle of an Activity Dialog Each Dialog window must
455. so want to set its maxHeight and minHeight attributes to a dimension that gives the graphic reasonable bounds for the settings screen for example 75px 3 Below the ImageButton control add another LinearLayout control Set its orientation attribute to vertical Set the layout_width and layout_height attributes to fill_parent Now move the nickname controls the TextView control called TextView_Nickname and the EditText control called EditText_Nickname into this layout At this point save the settings xml layout file If you rerun the application in the emulator the settings screen should now look like Figure 13 3 Password _ z D A Set Password _ No Password Set Birth Pate Pick Date No Date Set we Gender Prefer Nat To Say Working with ImageButton Controls 221 Working with ImageButton Controls The ImageButton control is a special type of button that displays a Drawable graph ic instead of text Figure 13 3 showed an ImageButton control used to display an avatar graphic as part of the settings screen The ImageButton and Button controls are both derived from the View class but they are unrelated to each other otherwise The Button class is actually a direct sub class of TextView think of it as a line of text with a background graphic that looks like a button whereas the ImageButton class is a direct subclass of ImageView Any graphics displayed within an ImageButton control should be st
456. sources in res menu colors xml to include colors for the screen title TextView attributes as well as the TextView items displayed within the ListView You should also update the resources in res values dimens xml to include dimensions for the title text and the ListView item text For specific resource configurations you can use the values provided in the book source code as a guide or configure your own custom values After you have saved the resource files you can begin to use them in the layout resource files used by the main menu screen Updating the Main Menu Screen Layouts Perhaps you have noticed by now that the main menu screen relies on layout resource files plural The master layout file menu xml defines the layout of the overall screen You must also create a new layout file template for each item in your ListView control 132 Dw HOUR 8 Implementing the Main Menu Screen Updating the Master Layout Again you open the Eclipse layout resource editor and remove all existing controls from the menu xm1 layout file You then follow these steps to generate the layout you want based on your intended layout design 1 Add a new LinearLayout control and set its background attribute to drawable bkgrnd All subsequent controls will be added inside this LinearLayout control Add a RelativeLayout control Set its Layout_width attribute to wrap_con tent and its layout_height attribute to wrap_content With
457. sources you use in the scores screen layout you must also add a new type of resource an XML file resource file 152 Oat HOUR 9 Developing the Help and Scores Screens The scores for the Been There Done That application will eventually be sourced from a remote server but for now you can build the screen and use some mock score data This mock score data will be provided in XML so you can mimic the structure you will use when the real scores are available In this instance you include in the res xml resource directory two XML files allscores xml and friendscores xm1l that represent the mock score data lt xml version 7 0 encoding utf 8 gt lt This is a mock score XML chunk gt lt scores gt lt score username LED score 12345 rank 7 gt lt score username SAC score 12344 rank 2 gt lt score username NAD score 12339 rank 3 gt lt scores gt The score data uses a very simple schema A single lt scores gt element has a number of child lt score gt elements Each lt score gt element has three attributes username score and rank For this example you can assume that the score data will be sorted and limited to the top 20 or so scores Updating the Scores Screen Layout The scores screen user interface is defined in the scores xml layout file To update this layout to your intended layout design you follow these steps The Eclipse layout resource editor doe
458. ss can be used to simplify tab screens A Tabify B TabActivity C TabController 3 True or False XML files are handled by the XML Resource Manager so no parsing is necessary 4 What type of control can be used to enable scrolling A ScrollLayout B Scroller C ScrollView Answers 1 True The TextView control can display large quantities of text with optional horizontal and vertical scrollbars 2 B A screen that requires only a tab set can use the TabActivity class to han dle tabbing setup and tasks efficiently 3 False XML files can be included but still need to be parsed Three parsers are available with the default resource parser being XML Pull Parser 4 C The Scroll1View control can be used to wrap child View controls within a scrolling area 160 HOUR 9 Developing the Help and Scores Screens Exercises 1 Launch the application and click each of the links in the help screen text Note how easy it can be to integrate Android applications into the Android platform Try launching some other kinds of intents and seeing what happens For a good list of intents check out the Intents Registry at http www openintents org en intentstable 2 Add a third tab to the scores screen to display the user s current score Make the content of this new tab different from the other two tabs by including a TextView control instead of a TableLayout control The user s current score will be be stored as an application pr
459. ss within the application package Try It Yourself To register a new activity in the Droid1 project follow these steps 1 Open the Droid1 project in Eclipse 2 Right click src com androidbook droid1 and choose New Class The New Java Class window opens 3 Name your new class DroidActivity2 4 Click the Browse button next to the Superclass field and set the superclass to android app Activity 5 Click the Finish button You see the new class in your project 6 Make a copy of the main xml layout file in the res layout resource directo ry for your new activity and name it second xml Modify the layout so that you know it s for the second activity For example you could change the text string shown Save the new layout file 10 11 Defining Activities Open the DroidActivity2 class Right click within the class and choose Source Override Implement Methods Check the box next to the onCreate Bundle method This method is added to your class Within the onCreate method set the layout to load for the new activity by adding and calling the setContentView R layout second method Save the class file Open the Android manifest file and click the Application tab of the resource editor In the Application Nodes section of the Application tab click the Add button and choose the Activity element The attributes for the activity are shown in the right side of the screen If you have an existing Activity s
460. st providers return latitude and longitude but not all can calculate altitude You use the getLatitude and getLongitude methods to retrieve the coordinates from the Location object Receiving Location Updates When you need more current information and want to know when the location changes you can register for periodic location updates by using the requestLocationUpdates method of the LocationManager class This method allows an activity to listen to events from a specific provider for example the best provider given your criteria This frequency of notifications can be adjusted by spec ifying the minimum time in milliseconds and the minimum distance interval in meters between updates To receive a notification when the location changes you should have the interested activity implement the LocationListener android location LocationListener interface This interface has a number of helpful callback methods which allow the activity to react when the provider is enabled and disabled when its status changes and when the location changes Resolving the current location can take some time Therefore you ll want to con Watch sider putting most LBS calls in a worker thread separate from the main UI thread ut or writing a background service to support your application We will discuss threading later in this book 246 Oat HOUR 14 Adding Support for Location Based Services Using Geocoding Services
461. state In this hour you wire up the screen at the heart of the Been There Done That applica tion the game play screen This screen prompts the user to answer a series of trivia ques tions and stores the resulting score information Because the screen must display a dynamic series of images and text strings you can use several new View controls includ ing ImageSwitcher and TextSwitcher to help transition between questions in the quiz You can also update QuizGameActivity with game logic and game state information including the retrieval of batches of new questions as a user progresses through the quiz Designing the Game Screen The game screen must lead the user through a series of trivia questions and log the num ber of positive responses the score Each trivia question has a corresponding graphic to display For example the game might show the user a picture of a mountain and ask if the user has ever climbed a mountain 198 FIGURE 12 1 Rough design for the Been There Done That game screen HOUR 12 Adding Application Logic Unlike previous screens you have developed the game screen does not need the cus tomary title bar Instead you want to use the entire screen to display the game com ponents Figure 12 1 shows a rough design of the game screen TRIVIA QUESTION You want the game screen to share some common features with the rest of the appli cation It should use the same background graphic font and co
462. stener method 136 online Android resources 425 426 onLongClick method 227 onLongPress gesture 352 onOptionsltemSelected method 140 onPause method 49 122 onPostExecute method 266 270 273 onPreExecute method 265 268 272 onPrepareDialog method 53 183 186 onProgressUpdate method 265 269 onReceive method 309 onResume method 49 onRetainNonConfiguration Instance method 338 onScroll gesture 352 onShowPress gesture 351 onSingleTapConfirmed gesture 351 onSingleTapUp gesture 351 onStartCommand method 316 onUpdate method 309 311 Open Handset Alliance 7 8 425 openFilelnput method 358 openFileOutput method 359 OpenGL ES 120 355 Openintents 362 425 Openintents org website 53 openRawResource method 72 147 OpenSocial initiative 301 openStream method 268 operating systems configuring for device debugging 414 supported operating systems 409 options menus adding resources to 138 139 adding to activities 139 handling menu selections 140 org w3c dom package 72 org xml sax package 72 org xmlpull package 72 organizing code 418 imports 415 416 orientation sensor 362 Override Implement Methods command Source menu 415 overriding dolnBackground method 273 P PackageManager class 392 packages android bluetooth 363 android database 359 android database sqlite 359 android gesture 352 android gr
463. sult by implement ing the calling activity class s onActivityResult method The startActivityForResult method takes two parameters the intent to launch and a developer defined request code In this case the calling activity is QuizSettingsActivity You have two instances in which you want to start a new activity The first instance is when the user clicks on the ImageButton control to start the camera capture activity The second instance is when the user long clicks on the ImageButton control to start the image gallery Therefore you need to define two request codes within QuizSettingsActivity static final int TAKE_AVATAR_CAMERA_REQUEST 1 static final int TAKE_AVATAR_GALLERY_ REQUEST 2 We will talk more about the startActivityForResult method in a moment but for now let s focus on how the QuizSettingsActivity handles the results returned when the launched activity completes You handle the result returned by the activity by implementing the onActivityResult method of the QuizSettingsActivity class Because you have more than one request code you add a switch statement with two cases one for camera results and one for image picker results protected void onActivityResult int requestCode int resultCode Intent data switch requestCode case TAKE_AVATAR_CAMERA_REQUEST if resultCode Activity RESULT_CANCELED Avatar camera mode was canceled else if resultCode Activity RESULT_OK TODO HANDLE PHOT
464. swers 1 A and C The ViewSwitcher class has two subclasses TextSwitcher for ani mating between two TextView controls and ImageSwitcher for animating between two ImageView controls 2 False The TextView controls displayed by a TextSwitcher control can be cre ated on the fly by using ViewFactory 3 True Many standard Java packages are available within the Android SDK There are also a number of packages specially designed for Android under the android package tree See the Android SDK documentation for a complete list of available packages Exercises 1 Add a new option to the options menu of the game screen to reset the trivia quiz Make sure you clear only the appropriate game settings not all of the preferences in SharedPreferences 2 Modify the application to use a different data structure like a linked list instead of a Hashtable HOUR 13 Working with Images and the Camera What You l Learn in This Hour Designing the avatar feature Working with ImageButton controls Working with the camera and the gallery gt gt gt Launching activities and handling results gt gt Working with bitmaps In this hour you add a new feature to the Been There Done That application the ability for the user to add a custom avatar or small graphic from the settings screen The user will be able to set the avatar in two ways by using the camera that is built in to the handset or by choosing an image that
465. t Designing an App Widget Handling App Widget User Events Working with Widget Background Operations Summary Q amp A Workshop Part IV Adding Polish to Your Android Application HOUR 19 Internationalizing Your Application General Internationalization Principles How Android Localization Works Android Internationalization Strategies Using Localization Utilities Summary Q amp A Worksho EOE eee HOUR 20 Developing for Different Devices Configuration Management for Android Summary Q amp A Workshop 291 291 292 300 302 302 303 305 305 313 314 318 318 319 321 321 322 327 329 330 332 333 333 343 343 344 xi Contents HOUR 21 Diving Deeper into Android 347 Exploring More Core Android Features 347 Designing Advanced User Interfaces 349 Working with Multimedia 353 Working with 2D and 3D Graphics 354 Personalizing Android Devices 356 Managing and Sharing Data 358 Accessing Underlying Device Hardware 362 Summary 364 Q amp A 364 HOUR 22 HPne Android Applications 2 367 Testing Best Practices 367 Maximizing Test Coverage 371 Summary 380 Q amp A 380 Workshop 381 Part V Publishing Your Application HOUR 23 Getting Ready to Publish 383 Understanding the Release Process 383 Preparing the Release Candidate Build 385 Testing the Application Release Candidate 386 Packaging and Signing an Application 387 Testing the Signed Application Package 390 Summary 392 Q amp A 392 Workshop 393
466. t Magnetic field sensor Measures magnetism in three dimensions gt Orientation sensor Measures a device s orientation gt Temperature sensor Measures temperature gt Proximity sensor Measures the distance from the device to a point in space The Android emulator does not simulate any device sensors natively but Openintents provides a handy sensor simulator www openintents org en node 23 This tool simulates accelerometer compass and orientation sensors as well as a temperature sensor and it transmits data to the emulator You can also test sensor functionality on the target device The SensorManager object is used to gather data from the device sensors You can retrieve an instance of SensorManager by using the getSystemService method Accessing Underlying Device Hardware 363 Working with Wi Fi Applications with the appropriate permissions ACCESS_WIFI_STATE and CHANGE_WIFI_STATE can access the built in Wi Fi sensor on a device by using the WifiManager object You can retrieve an instance of Wif iManager by using the getSystemService method The Android SDK provides a set of APIs for retrieving information about the Wi Fi networks available to a device as well as Wi Fi network connection details This information can be used for tracking signal strength finding access points or per forming actions when connected to specific access points The emulator does not emulate Wi Fi support so you n
467. t the debugger to an actual device and debug directly 3 There are a number of target platforms available and more are added with each new SDK release Some important platform targets include Android 1 1 Android 1 5 Android 1 6 Android 2 0 Android 2 0 1 and Android 2 1 Targets higher than Android 1 1 can include the Google APIs if desired These targets map to the AVD profiles you must create in order to use the Android emulator 4 False The Android emulator is a generic device but it can support several dif ferent skins For a complete list of skins supported see the Android SDK and AVD Manager in Eclipse Exercises 1 Launch the Android emulator and browse the settings available Change the language settings Uninstall an application 2 Launch the Android emulator and customize your home screen Change the wallpaper Install an AppWidget Get familiar with how the emulator tries to mimic a real handset Note the limitations such as how the dialer works 3 Try launching the Hierarchy Viewer tool with the Droid1 project you created in Hour 1 Note how you can drill down to see the TextView_controls you created This page intentionally left blank HOUR 3 Building Android Applications What You l Learn in This Hour gt Designing a typical Android application Using the application context gt Working with activities intents and dialogs gt Logging application information Every platform tec
468. t Application Project Wizard defaults in Eclipse 376 HOUR 22 Testing Android Applications Right click the package name within the src folder of your test project Choose New JUnit Test Case Modify the Name field to say QuizSettingsActivityTests W N PR Modify the Superclass field to say android test ActivityInstrumentation TestCase2 lt QuizSettingsActivity gt Ignore the warning that says Superclass does not exist 5 Modify Class Under Test to say com androidbook triviaquiz22 QuizSettingsActivity 6 Click Finish 7 In the newly created file manually add an import statement for QuizSettingsActivity or organize your imports 8 Finally add the following constructor to the newly created class public QuizSettingsActivityTests super com androidbook triviaquiz22 QuizSettingsActivity class Now that your test case file is ready you can test the Nickname field and make sure it matches the value of the nickname in SharedPreferences and that it updates after a new string is entered You first need to modify the setUp method to per form some common behavior You get the nickname EditText object for use in the other two tests The following code does just that Override protected void setUp throws Exception super setUp final QuizSettingsActivity settingsActivity getActivity nickname EditText settingsActivity findViewById R id EditText_Nickname The method call for getA
469. t Project Recall from Hour 1 Getting Started with Android when you first created a project using Eclipse that the wizard has an option for creating a test project You re now going to leverage that option to get up and running quickly with creating test cases Maximizing Test Coverage Conveniently the option for creating a test project is also available after a project already exists To create a test project for an existing Android project in Eclipse fol low these steps 1 Choose File New Project 2 Under the Android option choose Android Test Project 3 In the section labeled Test Target choose An Existing Android Project and click the Browse button 4 Find the project you want to test and select it The wizard fills in the rest of the fields with reasonable default values as shown in Figure 22 2 Test Project Name TriviaQuiz22Tests Content J Use default location Test Target Select the project to test This project An existing Android project ToviaQuiz22 Tacs Paans Martna cams sinide shiim Baia Target 5 Click Finish Your new test project is created Creating a Test Case When you have your test project in place you can write test cases You will now create a test case that tests the behavior of the Nickname field of the settings screen controlled by the QuizSettingsActivity class To do this first follow these steps to create the empty test case file 375 FIGURE 22 2 Tes
470. t a picker dialog Pick a Place launching the r Google Maps ELLE application The Great Pyramids Coordinates 4 29 97611 31 132778 gt gt If you press the Menu button in the Maps application you can change the map mode to satellite and zoom in to see the Great Pyramids as well as all the tour buses and the Sphinx as shown in Figure 14 11 250 HOUR 14 Adding Support for Location Based Services FIGURE 14 11 Using the x x Google Maps D Tis fi SA application to zoom in satel lite view Working with Third Party Services and Applications The built in LBS features of the Android SDK are located in the android location package Basic LBS functionality such as getting a location fix from satellite trian gulation is built into the Android SDK However many of the most interesting and powerful mapping and LBS related features on Android phones are not actually built into the basic Android SDK but are part of the Google APIs that ship along with the Android SDK Working with Google APIs and Advanced Map Features Map features can be built into applications using the Google API add on The following are some of the features available in the com google android maps package gt A MapView control for displaying an interactive map within a layout gt AMapActivity class to simplify MapView controls on a screen Q amp A 251 gt The GeoPoint class which encapsulates position information gt Classe
471. t exploring the complete life cycle of a service However generally speaking the onCreate method is called followed by either the onStartCommand or onBind method depending on the type of service and how it was started When the service is finished either because it is or there is no process bound to it the onDestroy method is called At this point put the following code in to the QuizWidgetProvider class public static class WidgetUpdateService extends Service Thread widgetUpdateThread null private static final String DEBUG_TAG WidgetUpdateService Override public int onStartCommand Intent intent int flags final int startId widgetUpdateThread new Thread public void run code moved from onUpdate method widgetUpdateThread start return START_REDELIVER_INTENT Override public void onDestroy widgetUpdateThread interrupt super onDestroy Override public IBinder onBind Intent intent no binding can t from an App Widget return null This is the service implementation as it would appear after moving the code from the onUpdate method to the run method of the thread created in the onStartCommand method The full implementation of the App Widget can be found in the code provided on the website for this book http www informit com title 9 780321673350 Now the Android manifest file needs to be updated so the system knows about this servic
472. t important settings your application requires are set using attrib utes and child tags of the lt manifest gt and lt application gt blocks 82 HOUR 5 Configuring the Android Manifest File Naming Android Packages You define the package within the Android manifest file in the lt manifest gt tag using the package attribute as follows lt manifest xmlns android http schemas android com apk res android package com androidbook droid1 android versionCode 7 android versionName 7 0 gt If you use the Android project wizard in Eclipse to create a project you must fill in the package name at that time That package name is used in the default Android manifest file Linking Secondary Libraries Applications can use the lt uses library gt tag to link to other libraries in addition to the standard Android packages This feature is available on the Application tab of the resource editor Here s an example lt uses library android name com company sharedutilities gt Versioning an Application Manifest version information is used for two purposes gt To organize and keep track of application features gt To manage application upgrades For this reason the lt manifest gt tag has two separate version attributes a version name and a version code Setting the Version Name The version name is the traditional versioning information used to keep track of application builds Smart versioning
473. tSimOperatorName 280 getSimSerialNumber 280 getSimState 280 getString 64 177 getSubscriberld 280 getSystem 63 getSystemService 261 279 362 363 getText 168 176 getVoiceMailNumber 280 getWidgetData 311 getXml 72 156 handleAnswerAndShowNext Question 2114 handleNoQuestions 213 i Log class 54 inflate 191 inputStreamToString 147 insertScoreRow 270 isNetworkRoaming 280 listen 279 How can we make this index more useful Email us at indexes samspublishing com 446 methods loadQuestionBatch 273 makeView 204 205 managedQuery 360 next 156 onActivityResult 49 52 224 225 228 onAnimationEnd 123 onBind 316 onCancelled 270 271 OnClickListener 222 onCreate 49 171 176 208 268 316 onCreateDialog 53 183 185 190 296 onCreateOptionsMenu 139 onDateSet 185 onDeleted 309 onDestroy 49 177 316 onDisabled 309 onEnabled 309 onltemClick 135 136 OnltemClickListener 136 onLongClick 227 onOptionsltemSelected 140 onPause 49 122 onPostExecute 266 270 273 onPreExecute 265 268 272 onPrepareDialog 53 183 186 onProgressUpdate 265 269 onReceive 309 onResume 49 onRetainNonConfiguration Instance 338 onStartCommand 316 onUpdate 309 311 openFilelnput 358 openFileOutput 359 openRawResource 72 147 openStream 268 parse 24
474. tag called lt questions gt which can contain a number of lt question gt tags Each lt question gt tag has three attrib utes the question identifier number the question itself text and the URL to the image associated with the question imageUr1 Note that you use remote graphics 202 HOUR 12 Adding Application Logic sourced from the Internet instead of adding each and every question graphic to the resources of the application Updating the Game Screen Layout The game xml layout file dictates the user interface of the game screen Again you open the Eclipse layout resource editor and remove all existing controls from the lay out You then follow these steps to generate the layout you want based on your design 1 Add a new LinearLayout control and set its background attribute to drawable bkgrnd All subsequent controls will be added inside the LinearLayout control Add a RelativeLayout control and set layout_width to wrap_content and layout_height to wrap_content Within the RelativeLayout control add four ImageView controls one for each corner of the screen Set each control s image src attribute to the draw able quizicon graphic Give each ImageView control a specific id attribute id ImageView_Header id ImageView_Header2 id ImageView_Header3 and id ImageView_Header4 Find the ImageView control with the id attribute set to ImageView_Header and set its layout_alignParentLeft and la
475. tar from a custom graphic and the graphic chosen must be displayed on the settings screen Of the various controls available in Android the ImageButton control would be able to handle both tasks To incorporate your avatar design changes into the res layout settings xml layout file you need to modify the region of the screen where the nickname controls reside Because you want to add a control to the left of the nickname controls you need to encapsulate all three controls the avatar ImageButton nickname label TextView and nickname EditText controls inside a child layout control such as a nested LinearLayout Control horizontally oriented By nesting the nickname controls in their own vertically oriented LinearLayout control you get the intended results Figure 13 2 shows the layout updates required by the avatar feature Adding an Avatar to the Settings Screen Layout 219 FIGURE 13 2 The settings screen layout updates required for the TextView Nickname avatar feature LinearLayout Horizontal Orientation EditText Nickname Input But wait You want the user to be able to configure the avatar by using the camera to take a new picture or by choosing an image already saved on the device No problem You can do this by handling clicks and long clicks on the same Button control The user can click the ImageButton control to launch the camera or long click the same ImageButton control to launch the image picker
476. tch the user Some notification methods such as vibration must be tested on the ut device because the Android emulator does not simulate this type of action Designing Advanced User Interfaces The best and most popular applications on the Android platform have one thing in common Each has an excellent well designed user interface You ve worked with many of the common user interface features of Android such as layouts and user interface controls However the Android SDK has many other exciting user interface features including the following gt The ability to apply consistent settings across many controls or entire screens using styles and themes gt The ability to design and reuse custom user interface components gt A powerful input method framework gt The ability to detect various screen gestures gt A text to speech TTS engine gt Speech recognition support Using Styles and Themes The Android SDK provides two powerful mechanisms for designing consistent user interfaces styles and themes You can use themes and styles to make application screens consistent and easy to maintain A style is a grouping of common View attribute settings that can be applied to any number of View controls For example you might want all View controls in your application such as TextView and EditText controls to use the same text color font and size You could create a style that defines these three attributes and apply it
477. teed to be unique gt Resources are conveniently located for handset customization gt Localization and internationalization are straightforward The Android platform supports a variety of resource types see Figure 4 1 which can be combined to form different types of applications Android applications can include many different kinds of resources The following are some of the most common resource types gt Strings colors and dimensions gt Drawable graphics files gt Layout files gt Raw files of all types Resource types are defined with special XML tags and organized into specially named project directories Some res subdirectories such as the drawable layout and values directories are created by default when a new Android project is created while others must be added by the developer when required Using Application and System Resources Android Application Resources Game Example Chippy s Revenge DRAWABLES Graphics and Icons ANDROID APPLICATION CHIPPY S REVENGE LAYOUT FILES Screen User Interfaces This is the help text for Chippy s Revenge a game about collecting nuts and avoiding cats Resource files stored within res subdirectories must abide by the following rules gt Resource filenames must be lowercase gt Resource filenames may contain letters numbers underscores and periods only gt Resource filenames and XML name attributes must be uniqu
478. teps 1 Create a strings xml resource file for each language Each string that is to be localized must appear in each resource file with the same name so it will be programmatically loaded correctly Any strings you don t want to localize can be left in the default English res values strings xml file 2 Save the French strings xml resource file to the res values fr directory 3 Save the German strings xml resource file to the res values de directory Android can now grab the appropriate string based on the system locale However if no match exists the system falls back on whatever is defined in the res values directory This means that if English or Arabic or Chinese or Japanese or an unex pected locale is chosen the default fallback English strings will be used Similarly you could provide a German specific drawable resource to override one in the default res drawable directory by supplying one with the same name in the res drawable de directory 326 how HOUR 19 Internationalizing Your Application Specifying Region Specific Resources You may have noticed that the previous example specifies high level language set tings only English but not American English versus British English vs Australian English Don t worry You can specify the region or locale as part of the resource directory name as well To specify strings for a specific language and locale you must supply the resource under a s
479. ter the SDK is installed 3 What is the most popular IDE for Android development A Eclipse B IntelliJ C Emacs 4 True or False You can use Eclipse for handset debugging Workshop 25 Answers 1 D The Open Handset Alliance is a business alliance that represents all levels of the handset supply chain 2 False You must first create an AVD 3 A Eclipse is the most popular IDE for Android development Other IDEs can be used but they will not enable you to use the ADT plug in that is integrated with Eclipse 4 True Eclipse supports debugging within the emulator and on the handset Exercises 1 Visit http developer android com and take a look around Check out the online Developer s Guide and reference materials Check out the Community tab and considering signing up for the Android Beginners and Android Developers Google Groups 2 Add more text to the Droid 1 application To do this first add another String resource to the strings xml resource file and save this file Next use the layout resource editor to modify the main xml layout file to add a second TextView control Set the text attribute of the TextView control to your newly created String resource Finally rerun the application in the emulator to see the results 3 Add to your Eclipse workspace one of the Android sample projects provided with the Android SDK Browse through the project files and then create a run configuration and launch the samp
480. tes and downloadable source code What Is and Isn t in This Book While we specifically targeted Android SDK Version 2 1 in this book many of the examples were tested on handsets running a variety of Android SDK versions The Android SDK is updated very frequently every few months We kept this in mind when choosing which features of the SDK to highlight to ensure maximum forward and backward compatibility When necessary we point out areas where the Android SDK version affects the features and functionality available to the developer This book is written in a beginner s tutorial style If you re looking for an exhaustive refer ence on Android development with cookbook style code examples and a more thorough examination of all the features of the Android platform we recommend our other more advanced Android book Android Wireless Application Development which is part of the Addison Wesley Developer s Library series 4 Introduction What Development Environment Is Used The code in this book was written using the following development environments gt Windows 7 and Mac OS X 10 6 gt Eclipse Java IDE Version 3 5 Galileo gt Eclipse JDT plug in and Web Tools Platform WTP gt Sun Java SE Development Kit JDK 6 Update 18 gt Android SDK Version 2 1 Primary target developed and tested on a variety of SDK versions gt Various Android handsets Android SDK 1 6 2 0 1 and 2 1 What Conventions Are Used i
481. th 52 53 passing information with 51 52 internationalizing application names 92 launching in emulator 109 with intents 52 53 layouts accessing programmatically 71 designing with Layout Resource Editor 68 70 designing with XML 69 explained 67 68 logging application information 54 main menu screens adding project resources 131 designing 127 130 layout requirements 129 ListView control 129 134 137 screen headers building with RelativeLayout 129 updating layouts 132 133 naming 84 options menus adding resources to 138 139 adding to activities 139 handling menu selections 140 permissions 347 including in Android manifest file 92 managing 88 91 prototypes activities implementing 105 106 activity requirements 96 97 application preferences creating 106 108 creating new project 103 debug configuration 108 game screen features 102 help screen features 98 99 How can we make this index high level game features 96 main menu screen features 98 project resources adding 104 scores screen features 100 settings screen features 100 101 splash screen features 97 98 providing descriptions for 85 providing icons for 84 publishing See publishing removing from Android Market 402 responsiveness 367 scores screens adding resources to 151 152 completed scores screen 157 delays in loading 158 designing 149 layout requirements
482. that after it scales it ll still be at the bottom Implementing the Main Menu Screen Layout 8 Now add a ListView control called ListView_Menu just below the ImageView Set its layout_width attribute to fill_parent and layout_height attribute to wrap_content Additionally set its Layout_alignParentTop attribute to true We add this second attribute so the control will draw over the top of the image At this point save the menu xm1 layout file The Eclipse layout resource editor does not display ListView controls in design mode You must view a ListView control by using the Android emulator In this case the layout designer does not reflect actual application look and feel Adding the ListView Template Layout You now need to create a new layout called res layout menu_item xml that will serve as a template for your ListView items In this case the menu_item xml layout file will contain a TextView control The TextView control has all the typical attributes assigned except for one the text itself The text attribute will be supplied by the ListView control At this point you can tweak the TextView attributes for textColor and textSize which you created as color and dimension resources earlier The menu_item xml file looks like this lt TextView xmlns android http schemas android com apk res android android layout_width fill_parent android textSize dimen menu_item_size android text test string a
483. the HttpGet class Because you are posting form query variables you want to use the URLEncodedUtils utility with a List container of BasicNameValuePair objects to assist with creating the final URL for the request Finally the whole network operation must be wrapped inside the AsyncTask object so that the user interface can continue to respond while the network request is being handled Creating an AsyncTask Class to Handle Uploads To upload the user settings information to the application server you need to add another AsyncTask subclass called AccountTask to QuizSettingsActivity The AccountTask class can be run using the execute method whenever the player changes a setting on the settings screen see Figure 16 1 You can also run this task when the user first launches the application to set up a unique player identifier on the application server for this player on this particular device even if the person has not entered his or her nickname or email address This could also allow you to retrieve the settings data from the server via two way syncing Uploading Data to a Remote Application Server Ga G 10 06 pm Settings Nickname LaurieDarcey Email led host com Passw e Password Set Birth Date NI No Date Set Gender Prefer Not To Say Favosite Place The details of the AccountTask subclass are very similar to those of the other AsyncTask subclasses you have written over the past two ho
484. the calendar could theoretically be used for nefarious purposes Thus per mission is required to access this information Workshop 93 Workshop Quiz 1 True or False Every Android application needs an Android manifest file 2 True or False The android versionCode numbers must correspond with the application android versionName 3 What is the permission for using the camera A android permission USE_CAMERA B android permission CAMERA C android permission hardware CAMERA 4 True or False When installing an application the user is shown the permis sions requested in the Android manifest file Answers 1 True The Android manifest file is an essential part of every Android project This file defines the application s identity settings and permissions 2 False The android versionCode attribute must be incremented each time the application is deployed and it can be upgraded This number need not match the android versionName setting 3 B You use the android permission CAMERA permission to access the camera 4 True This way the user knows what the application might attempt to do such as take a picture or access the user s contacts Exercises 1 Create a new icon for the Droid1 project 2 Create another Activity class Edit the permissions to use a permission of your choice Also try to use feature without requesting the appropriate per mission and observe the results 3 Perform a modificat
485. the capture screen click Save to save the screenshot to your local hard A drive Working with the Android Emulator Viewing Log Information The LogCat logging utility that is integrated into DDMS allows you to view the Android logging console You may have noted the LogCat logging tab with its diag nostic output in many of the figures shown so far in this chapter We will talk more about how to implement your own custom application logging in Hour 3 Building Android Applications Filtering Log Information Eclipse has the ability to filter logs by log severity You can also create custom log filters by using tags For more information on how to do this see Appendix B Eclipse IDE Tips and Tricks Working with the Android Emulator The Android emulator is probably the most powerful tool at a developer s disposal It is important for developers to learn to use the emulator and understand its limita tions The Android emulator is integrated with Eclipse using the ADT plug in for the Eclipse IDE Emulator Limitations The Android emulator is a convenient tool but it has a number of limitations gt The emulator is not a device It simulates general handset behavior not spe cific hardware implementations gt Sensor data such as satellite location information battery and power set tings and network connectivity are all simulated using your computer gt Peripherals such as camera h
486. the most popular application stores and can now begin to sell your own applications there Perhaps you already have some great app ideas in mind Fire up Eclipse and start coding When you start building applications drop us a note and tell us about them Our contact information is available in Appendix C Supplementary Materials We d love to hear from you Q What languages are supported by the Android Market A The Android Market currently supports over a dozen languages and more are added all the time The following are some of the languages currently support ed by the Android Market gt American English en_US gt French frangais fr_FR gt German Deutsch de_DE gt Italian italiano it_IT gt Spanish Espariol es_ES gt Dutch Nederlands nl_NL gt Polish polski pl_PL gt Czech testina cs_CZ gt Portugese portugu s pt_PT gt Taiwanese P X RE zh_TW gt Japanese AAR ja_JP gt Korean et 4 OH ko_KR gt Russian pyCCKN ru_RU 406 HOUR 24 Publishing on the Android Market Q How can I protect my hard work from software piracy A After you spend time money and effort building a valuable Android applica tion it makes sense to protect yourself against reverse engineering of trade secrets and software piracy Because Android applications are compiled for the Dalvik virtual machine most traditional Java obfuscation tools won t work Some tools such as ProGu
487. the options in the form of a ListView control is more appropriate This way if the list becomes longer than the screen you have built in scrolling capability In addition to the screen layout you want the main menu screen to have some bells and whistles You begin with the default behavior of each layout control and then add some custom flair to those controls For example you could add a nice back ground image behind the entire screen and add a custom selection graphic to the ListView control Finally you wire up the ListView control to ensure that when a user clicks on a spe cific list option he or she is taken to the appropriate screen This will allow users to easily access the rest of the screens you need to implement within the Been There Done That application Designing the Main Menu Screen 129 Determining Main Menu Screen Layout Requirements Now that you know how you want your main menu screen to look you need to translate your rough design into the appropriate layout design In this case you need to update the res layout menu xml layout file that is used by QuizMenuActivity In the case of the main menu layout you want some sort of header followed by a ListView control and then an ImageView control Building the Screen Header with RelativeLayout You know you want to display a TextView control for the screen title in the header Wouldn t it be nice if you also included graphics on each side of the TextView con t
488. third TextView control called TextView_PwdProblem provides feedback about whether the passwords match First you need to retrieve each of the controls final EditText p1 EditText findViewById R id EditText_Pwd7 final EditText p2 EditText findViewById R id EditText_Pwd2 final TextView error TextView findViewById R id 7TextView_PwdProblem Next you add TextWatcher to the second EditText control using the addTextChangedListener method like this p2 addTextChangedListener new TextWatcher Override public void afterTextChanged Editable s String strPass1 p1 getText toString String strPass2 p2 getText toString if strPass1 equals strPass2 error setText R string settings pwd_equal else error setText R string settings_pwd_not_equal Other required overrides do nothing 170 FIGURE 10 4 A Password dia log with two EditText con trols and a TextView control FIGURE 10 5 A Button control OiKtow HOUR 10 Building Forms to Collect User Input The user can type the password into the EditText_Pwd1 EditText control normally However each time the user types a character into the EditText_Pwd2 control you compare the text in both EditText controls and set the text of the TextView control called TextView_PwdProblem to reflect whether the text matches see Figure 10 4 Working with Button Controls The Button control on the Android platform is relat
489. thod 244 getQuestionImageDrawable method 206 getQuestionImageUrl method 207 getResources method 62 74 getSharedPreferences method 46 110 getSimOperator method 280 getSimOperatorName method 280 getSimSerialNumber method 280 getSimState method 280 getString method 64 177 getSubscriberld method 280 getSystem method 63 getSystemService method 261 279 362 363 getText method 168 176 getVoiceMailNumber method 280 getWidgetData method 311 getXml method 72 156 GIFs animated GIFs 119 global search integrating with 361 Google APIs 241 250 251 Google APIs Add On Reference website 251 Google App Engine 256 Google Developer Challenges 9 Google Maps 241 Google Open Handset Alliance 7 8 graphics android graphics package 355 OpenGL ES graphics API 355 GSM phones determining 279 280 handleAnswerAndShowNext Question method 211 handleNoQuestions method 213 Handler class 266 handsets handset databases 372 launching Android applications on 22 23 supporting 341 taking screenshots of 33 34 target handsets identifying and acquiring 371 testing on 373 hardware battery life 363 Bluetooth 363 power settings 363 sensor data reading 362 testing network applications on 259 Wi Fi 363 hashtables storing questions in 210 Hello World application creating debug and run con figurations 18 19 c
490. thods which require implementation However the one we re must interested in is the afterTextChanged method 192 HOUR 11 Using Dialogs to Collect User Input Now that you have inflated the view and configured it for use you can to attach it to AlertDialog To do this you use the AlertDialog Builder class AlertDialog Builder builder new AlertDialog Builder this builder setView layout builder setTitle R string settings_button_pwd First you set the view of AlertDialog Builder to the layout you inflated Then you set the title of the Dialog window with the setTitle method Your dialog will have two Button controls a positive button OK and a negative button Cancel Because you do not want this dialog cached for reuse by the activi ty both Button handlers need to call the removeDialog method which destroys the dialog QuizSettingsActivity this removeDialog PASSWORD_DIALOG_ID The positive button OK requires some handling When the user clicks the positive button you need to extract the password text from the EditText controls compare it and if two strings match store the new password builder setPositiveButton android R string ok new DialogInterface OnClickListener public void onClick DialogInterface dialog int which TextView passwordInfo TextView findViewById R id TextView_Password_Info String strPassword1 p1 getText toString String strPassword2 p2 getText toString
491. tion descriptions 85 providing application icons 84 setting debug information for applications 85 setting minimum Android SDK version 83 versioning applications 82 designating launch activity in 48 editing with Eclipse manifest file resource editor AndroidManifest xml tab 81 Application tab 78 79 Instrumentation tab 80 Manifest tab 78 79 Permissions tab 79 80 explained 77 78 lt manifest gt tag 82 preparing for release 385 386 lt receiver gt tag 307 lt uses library gt tag 82 updating for App Widgets 307 versioning applications 83 android debuggable attribute lt application gt tag 85 android description attribute lt application gt tag 85 android icon attribute lt application gt tag 84 android label attribute lt application gt tag 84 android minSdkVersion attribute lt uses sdk gt tag 83 android versionCode attribute lt manifest gt tag 82 android versionName attribute lt manifest gt tag 82 animation adding to splash screens 120 121 animating all views in layout 122 123 animating specific views 121 122 handling animation life cycle events 123 ImageSwitcher control 207 performance issues 124 types of 119 120 annotations UiThreadTest 378 App Widgets adding to Home screen 312 313 Android manifest file updates 307 AppWidgetProvider class implementation 309 311 background operations 314 315 creating service
492. tion mechanisms such as the Android Market Android developers have numerous options for distributing and commercializing their applications Introducing Android To understand where Android fits in with other mobile technologies let s take a minute to talk about how and why this platform came about Google and the Open Handset Alliance In 2007 a group of handset manufacturers wireless carriers and software developers notably Google formed the Open Handset Alliance with the goal of developing the next generation of wireless platform Unlike existing platforms this new platform would be nonproprietary and based on open standards which would lead to lower development costs and increased profits Mobile software developers would also have unprecedented access to the handset features allowing for greater innovation FIGURE 1 1 The Android mascot HOUR 1 Getting Started with Android As proprietary platforms such as RIM BlackBerry and Apple iPhone gained traction the mobile development community eagerly listened for news of this potential game changing platform Android Makes Its Entrance In 2008 the Open Handset Alliance announced the Android platform and launched a beta program for developers Android went through the typical revisions of a new platform Several prerelease revisions of the Android Software Development Kit SDK were released The first Android handset the T Mobile G1 began shipping in late 2008 Through
493. tionality out side the traditional boundaries of a mobile application by using App Widgets Developers can use the App Widget API to create mini controls or views that can be added to the user s Home screen These simple controls can provide a user with information about the application and remind the user to launch the application when necessary App Widgets can be useful for certain types of applications such as those that might need to inform the user of some status or update A weather application might include an App Widget that displays the current weather conditions at the given location on the Home screen A task management application might include an App Widget that informs the user of the next task on his or her to do list or how many tasks are left for the day A pic ture gallery application might include an App Widget that acts as a slideshow of all the pictures stored in the gallery 306 HOUR 18 Creating a Home Screen App Widget In this lesson you will create a simple App Widget for the Been There Done That application This App Widget will do the following gt Display the user s avatar gt Display the user s nickname gt Display the user s current score gt Launch the Been There Done That application when clicked Defining App Widget Properties App Widget definition and configuration properties are defined in a separate XML file and are then referenced from within the Android manifest file We ll get t
494. tired of watching the splash screen appear when you launch the applica tion simply modify the AndroidManifest xml file to launch QuizMenuActivity ow by default until you are done testing As you can see the main menu screen is beginning to take shape However clicking the menu items doesn t yet have the desired response Listening for ListView Events You need to listen for and respond to specific events within the ListView control Although there are a number of events to choose from you are most interested in the event that occurs when a user clicks an item in the ListView control To listen for item clicks you use the setOnItemClickListener method of the ListView Specifically you implement the onItemClick method of the AdapterView OnItemClickListener class like this menuList setOnItemClickListener new AdapterView OnItemClickListener public void onItemClick AdapterView lt gt parent View itemClicked int position long id TextView textView TextView itemClicked String strText textView getText toString if strText equalsIgnoreCase getResources getString R string menu_item_play Launch the Game Activity startActivity new Intent QuizMenuActivity this QuizGameActivity class 136 ow HOUR 8 Implementing the Main Menu Screen else if strText equalsIgnoreCase getResources getString R string menu_item_help Launch the Help Activity startActivity new Intent QuizM
495. tleties of why this happens are beyond the scope of this book but there is a great official Android blog post on this topic http android developers blogspot com 2009 01 avoiding memory leaks html Once you have retrieved a valid application context you can use it to access appli cation wide features and services Retrieving Application Resources You can retrieve application resources by using the getResources method of the application context The most straightforward way to retrieve a resource is by using its unique resource identifier as defined in the automatically generated R java class The following example retrieves a String instance from the application resources by its resource ID String greeting getResources getString R string hello Accessing Application Preferences You can retrieve shared application preferences by using the getSharedPreferences method of the application context You can use the SharedPreferences class to save simple application data such as configuration set tings Each SharedPreferences object can be given a name allowing you can organize preferences into categories or store preferences all together in one large set Working with Activities 47 For example you might want to keep track of each user s name and some simple game state information such as whether the user has credits left to play The follow ing code creates a set of shared preferences called GamePrefs and saves a f
496. to each TextView and EditText control within your application layouts 350 Dw HOUR 21 Diving Deeper into Android A theme is a collection of one or more styles Whereas you apply a style to a specific control such as a TextView control you apply a theme to all View objects within a specified activity Applying a theme to a set of View objects all at once simplifies making the user interface look consistent it can be a great way to define color schemes and other common View attribute settings across an application You can specify a theme programmatically by calling the Activity class s setTheme method You can also apply themes to a specific activity in the Android manifest file The Android SDK includes a number of built in themes which can be found in the android R style class For example android R style Theme is the default system theme There are themes with black backgrounds themes with and with out a title bar themes for dialog controls and more Designing Custom View and ViewGroup Controls You are already familiar with many of the user interface controls such as layout and View controls that are available in the Android SDK You can also create cus tom controls To do so you simply start with the appropriate View or ViewGroup control from the android view package and implement the specific functionality needed for your control or layout You can use custom View controls in XML layout files or you can
497. to enhance any functionality or features that are available This method can also be used on devices that include specialized features or functions not found on other devices but that your application may want to leverage when they are available Q amp A 343 A great example of how to use reflection to support multiple Android SDK versions Did you__ is available at http developer android com resources articles backward ow compatibility html Detecting the Android SDK Programmatically You can programmatically determine the version of Android by using the Build class android os Build Specifically you can check the Build VERSION class s SDK_INT value as defined in android os Build VERSION_CODES Defining Android SDK Specific Application Resources Much as developers can provide resources for specific language region and handset configuration options in applications they can also provide resources for specific versions of the Android SDK Recall from Table 20 1 that resource paths can also specify a particular Android API level number Summary In this hour you learned how to customize application resources for a variety of handset configurations including hardware and software requirements You also learned how to design applications to smoothly handle orientation changes Finally you learned how to develop applications for a variety of Android SDK versions Q A firmware upgrade broke my application What ca
498. to return the appropri ate Dialog window based on the incoming parameter the Dialog identifier Initializing a Dialog Because a Dialog window may be kept around by an activity it may be important to re initialize a dialog each time it is shown instead of just when it is created the first time For this purpose you can override the onPrepareDialog method of the activity While the onCreateDialog method may be called only once for initial dialog cre ation the onPrepareDialog method is called each time the showDialog method is called giving the activity a chance to initialize the dialog each time it is shown to the user Launching a Dialog You can display any dialog defined within an activity by calling its showDialog method and passing it a valid Dialog identifier one that will be recognized by the onCreateDialog method 184 HOUR 11 Using Dialogs to Collect User Input Dismissing a Dialog Most Dialog types have automatic dismissal circumstances However if you want to force a dialog to be dismissed you can simply call the dismissDialog method and pass in the Dialog identifier Removing a Dialog from Use Dismissing a Dialog window does not destroy it If the dialog is shown again its cached contents will be redisplayed If you want to force an activity to remove a dia log and not reuse it you call the removeDialog method and pass in the valid Dialog identifier Using DatePickerDialog Now you sho
499. trol called allScoresTab has the tag reference allTab The actu al tab label contains a TextView control and an icon a star Finally you set the contents of the tab to ScrollViewAl11Scores which wraps the TableLayout control called TableLayout_AllScores defined in the scores xml layout resource Next you add a second tab called friendsTab to the TabHost control The second tab is implemented much like the first only with different content friend scores only not all scores Setting the Default Tab At this point you need to identify which tab to show by default To do this you call the setCurrentTabByTag method and pass in the tag name of the tab host setCurrentTabByTag allTab Save the QuizScoresActivity java file and run the application in the Android emulator If you navigate to the scores screen you see the two tabs but you still have no score data to display If you have a screen that only displays a TabHost control consider using the Watch TabActivity class to simplify management of the TabHost control ut 156 HOUR 9 Developing the Help and Scores Screens Working with XML The Android platform has a number of mechanisms for working with XML data including support for the following gt SAX Simple API for XML gt XML Pull Parser gt Limited DOM Level 2 core support The XML technology you use depends on your specific project For this example you simply want to read through a s
500. trols cannot be used This means that the design of the layout is very limited App Widgets are not meant to display much information though and the customary way of enhancing the features of an App Widget is to trigger the launch of full activity when more powerful features or complex screens are required This functionality could be used to draw an entire screen or be limited to just a popup screen Either way activities launched from an App Widget no longer carry the limitations that an App Widget has from the required use of a RemoteViews object To design a layout for the App Widget create a new layout file called widget xml and place the following code in it lt xml version 7 0 encoding utf 8 gt lt RelativeLayout xmlns android http schemas android com apk res android android layout_width wrap_content Designing an App Widget 309 android layout_height wrap_content android id id widget_view gt lt ImageView android layout_centerInParent true android layout_height fill_ parent android layout_width fill_ parent android id id widget_image gt lt ImageView gt lt TextView android text id TextView01 android layout_width wrap_content android layout_height wrap_content android layout_alignParentTop true android layout_centerHorizontal true android id t id widget_nickname gt lt TextView gt lt TextView android text id TextView02 android layout_width wrap_conte
501. ts all the steps you need to follow to register for the key http code google com android add ons google apis mapkey html As part of this process you need to set up a Google account if you do not have one already 252 HOUR 14 Adding Support for Location Based Services Q How do design an application that needs more robust location information such as an update when the location changes A There are a number of ways to design LBS applications For starters the LocationManager object allows you to register an activity for periodic updates of location information including the ability to launch an intent when a spe cific location event occurs Make sure you move all LBS tasks off the main UI thread as they are time intensive use a worker thread the AsyncTask class or a background process instead Also only listen for location events when you must to avoid performance issues on the device Workshop Quiz 1 Developers need to consider which of the following when working with location based services A The user s privacy B The user s phone bill C The device s battery life D The accuracy and validity of the information provided by LBS and geocod ing services E The time it takes for location information to be resolved F All of the above 2 True or False In addition to the Button controls provided with AlertDialog other Button controls can be used as part of a custom layout 3 Which services are provid
502. tting 418 code organization 418 coding standards 368 colors explained 64 65 retrieving 65 supported color formats 65 commands Class New menu 415 Clean Project menu 420 Override Implement Methods Source menu 415 comments 416 commit method 212 committing EditText input 169 Community tab Android documentation 28 compress method 228 configuration management 333 335 debugging device debugging 414 USB debugging 413 414 EditText controls 168 power settings 363 ringtones 356 Spinner controls 173 TabHost control 155 wallpaper 356 357 conformance testing 370 ConnectivityManager class 261 contacting authors 425 Contacts application 37 Contacts content provider 360 contains method 177 containsKey method 210 content providers Browser 360 CallLog 360 Contacts 360 explained 360 361 live folders 361 MediaStore 360 UserDictionary 360 context menus 138 Context object getConfiguration method 329 getSystemService method 261 279 launching activities with 48 retrieving context for current process 46 How can we make this 435 DDMS Dalvik Debug Monitor Service controls See specific controls coordinates translating 247 copy protection 406 Create New Project in Workspace button New Android Project dialog 10 Create Project from Existing Sample button New Android Project dialog 13 Create Project from Existing Source bu
503. tting is set and if so load its value into the EditText input field called EditText_Nickname You can do this by using the contains and getString methods of SharedPreferences final EditText nicknameText EditText findViewById R id EditText_Nickname if mGameSettings contains GAME_PREFERENCES_NICKNAME nicknameText setText mGameSettings getString GAME_PREFERENCES_NICKNAME Here you check for the existence of a specific setting name defined as GAME_PREFER ENCES NICKNAME in SharedPreferences by using the contains method If the contains method returns true you extract the value of that setting a String setting from SharedPreferences by using the getString method The Nickname Email and Password settings are strings and can be extracted using the getString method However the Date of Birth setting must be extracted using the getLong method and the Gender setting requires the getInt method Application preferences are stored on the Android file system as XML files Preferences files can be accessed using the File Explorer of the Eclipse DDMS ow perspective SharedPreferences files are found in the following directory data data lt package name gt shared_prefs lt preferences filename gt xml Finally for testing purposes you override the onDestroy method of QuizSettingsActivity to log all current settings whenever the settings screen is destroyed Override protected void onDest
504. tton New Android Project dialog 13 create method 193 createChooser method 226 createFromResource method 173 createScaledBitmap method 229 Cube Live Wallpaper 357 currency Currency class 330 internationalization 330 Currency class 330 custom dividers adding to ListView 136 custom log filters 420 custom password dialog adding to QuizSettingsActivity class 190 193 designing 188 189 implementing layout 190 launching 193 custom selectors adding to ListView 137 custom views 350 d method Log class 54 Dalvik Debug Monitor Service See DDMS databases handset databases 372 SQLite databases 359 DateFormat class 330 DatePickerDialog 182 184 adding to QuizSettingsActivity class 184 185 initializing 185 186 launching 186 187 date internationalization 330 DDMS Dalvik Debug Monitor Service browsing file system with 31 debugging Android applications with 21 22 debugging applications with 29 30 Emulator Control 31 33 explained 39 File Explorer 31 managing tasks 30 managing tasks with 30 Screen Capture button 33 34 simulating incoming calls to emulator 31 32 simulating incoming SMS messages to emulator 33 taking screenshots of emulator or handset 33 34 viewing log information 35 index more useful Email us at indexes samspublishing com 436 debugging debugging Android applications with DDMS 21 22 29 30 debug configuration
505. tude settings This page intentionally left blank HOUR 15 Adding Network Support What You I Learn in This Hour gt Designing network applications gt Running tasks asynchronously gt Working with progress bars gt Downloading data from an application server In the next two hours you enable the Been There Done That application to handle two way network communication In this hour you concentrate your attention on download ing data from the Internet Specifically you modify the application to retrieve batches of quiz questions and live score data from a remote application server Designing Network Applications Although mobile devices have come a long way in terms of computing speed and data storage servers can still provide valuable processing power for backing up data or for pro viding ease of data portability between devices or access to portions of larger datasets that can t be retained on the local device Luckily mobile devices have also come a long way in terms of their ability to connect to networks and the Internet Most Android devices can connect to the Internet in multiple ways including through 3G and beyond networks or Wi Fi connections Android applications can use many of the most popular Internet proto cols including HTTP HTTPS TCP IP and raw sockets So far you have supplied only mock XML data in the Been There Done That application Now it s time to modify the application to contact
506. uestions Now let s work through the pseudo code and implement this method First you must retrieve the current game settings including the game score and the next question number from SharedPreferences int curScore mGameSettings getInt GAME_PREFERENCES_SCORE 0 int nextQuestionNumber mGameSettings getInt GAME_PREFERENCES_CURRENT_QUESTION 1 1 Next you need to increment the value of the next question in SharedPreferences Editor editor mGameSettings edit editor putInt GAME_PREFERENCES_CURRENT_QUESTION nextQuestionNumber 212 HOUR 12 Adding Application Logic If the user clicked the Yes button you also need to update the score and save it to SharedPreferences if bAnswer true editor putInt GAME_PREFERENCES_SCORE curScore 1 After you have changed all the SharedPreferences values necessary you save the changes with the commit method of the editor editor commit Next you check whether the next question is available in the hashtable If you need to retrieve a new batch of questions do so now if mQuestions containsKey nextQuestionNumber false Load next batch try loadQuestionBatch nextQuestionNumber catch Exception e Log e DEBUG_TAG Loading updated question batch failed e Finally you update the TextSwitcher and the ImageSwitcher controls with the text and image for the next question if mQuestions containsKey nextQuestionNumber true
507. ugging configuration 414 Eclipse IDE installation 410 magnetic field sensor 362 main menu screens adding project resources 131 defining features of 98 designing 127 130 layout requirements 129 ListView control 129 130 custom dividers 136 custom selectors 137 filling 134 135 listening for ListView events 135 136 screen headers building with RelativeLayout 129 updating layouts 132 133 makeView method 204 205 managedQuery method 360 managing activity state 49 application permissions 88 91 tasks with DDMS 30 manifest file See AndroidManifest xml file Manifest tab manifest file 14 78 79 lt manifest gt tag 82 maps Google Maps 241 launching map applications with intents 248 249 working with Google APIs 250 251 marketplaces AndAppStore 404 Android Market 8 425 billing 401 developer account benefits 402 developer accounts 396 397 402 explained 395 language support 405 locales 326 327 removing applications from 402 return policy 401 402 uploading applications to 397 400 MobiHand 404 PocketGear 404 SHOP4APPS 404 SlideME 404 master layouts updating for main menu screens 132 133 MediaController control 354 MediaPlayer class 353 MediaRecorder class 353 MediaStore 360 MenuActivity class 44 menus context menus 138 main menus See main menu screens options menus adding resources to 138 139 adding to activities 1
508. uiz 1 True or False Content providers always require an Android application to declare permissions in the Android manifest file 2 Which multimedia features are feasible on Android Ability to play audio Ability to play video Ability to record audio Ability to record video mo QO W R All of the above 3 True or False The indicator light on an Android device is accessible using the Android SDK 4 True or False This chapter covers all additional features of the Android SDK not covered elsewhere in this book Answers 1 False Content providers may require specific permissions However the enforcement of permissions depends on the content provider Check the specif ic content provider documentation for what specific permissions are required to access its provider interface 2 E The android media package includes support for playing and recording audio and video in a variety of formats Different Android devices have differ ent hardware available so check specific target devices to make sure they sup port the multimedia features an application requires 3 True You can use the NotificationManager class to access the LED indicator light on an Android device 4 False The Android SDK has many more features and nuances In addition the framework is being updated and enhanced very rapidly Various resources blogs articles and developer guides can be found at http developer android com Also see our blog for tips
509. uld add a Dialog window to the QuizSettingsActivity class Specifically you should add DatePickerDialog to handle input of the user s date of birth Adding DatePickerDialog to QuizSettingsActivity involves several steps 1 Define a unique identifier for the dialog within the activity 2 Implement the onCreateDialog method of the activity to return DatePickerDialog when supplied the unique identifier 3 Implement the onPrepareDialog method of the activity to initialize DatePickerDialog with the date of birth preference or the current date 4 Launch the DatePickerDialog using the showDialog method with the unique Dialog identifier Adding the DatePickerDialog to the QuizSettingsActivity Class To create DatePickerDialog you must first declare a unique identifier to represent the dialog as follows static final int DATE_DIALOG_ID 0 Next you need to implement the onCreateDialog method of QuizSettingsActivity and include a case statement for the new Dialog identifier Override protected Dialog onCreateDialog int id switch id case DATE_DIALOG_ID TODO Return a DatePickerDialog here Using DatePickerDialog return null Now let s look at how to construct a DatePickerDialog in detail Within the switch statement for DATE_DIALOG_ID you must return a valid DatePickerDialog for dis play The constructor for DatePickerDialog includes a DatePickerDialog OnDateSetListener parameter where you can p
510. ur 22 Testing Android Applications 11 Click the Finish button 12 FIGURE 1 2 The Android Project Wizard in Eclipse HOUR 1 Getting Started with Android New Android Project Creates a new Android Project resource Project name Droid Contents Create new project in workspace Create project from existing source Z Use default location CfUsers tauren sams Wws Oroydl Create project from existing sample Samples ApiDemos Build Target Target Name Vendor Prattorm APIL Android 2 0 1 Android Open Source Project Google APIs Google Inc Android 2 1 Android Open Source Project T Google APis Google Inc Standard Android platform 21 Properties Application name Droid 1 Package name Comandroidbook droid X Create Activity DroidActivity Min SOK Version 7 Exploring the Android Project Files You will now see a new Android project called Droid1 in the Eclipse File Explorer In addition to linking the appropriate Android SDK jar file the following core files and directories are created gt AndroidManifest xml The central configuration file for the application gt default properties A generated build file used by Eclipse and the Android ADT plug in Do not edit this file gt src folder Required folder for all source code gt src com androidbook droid1 DroidActivity java Main entry point to this application named DroidActivity This activity has been def
511. ur application works on the emulator does not guarantee that it will work on the handset Testing on a target handset is the safest way to ensure that an application works correctly because you are running the application on the same hardware that your users are going to use By mimicking the environment your users will use you can ensure that your application works as expected in the real world While it can be convenient to test with the handset plugged in this is not the way most users will use your application They will generally use battery power only Be sure to unplug the handset and test an application the way users will most likely encounter it Performing Automated Testing Collecting application information and building automated tests can help you build a better more bulletproof application The Android SDK provides a number of pack ages related to code diagnostics Application diagnostics fall into two categories gt Logging application information for performance or usage statistics gt Automated test suites based on the JUnit framework 373 waai wach Waie 374 Oat Dw HOUR 22 Testing Android Applications Logging Application Information At the beginning of this book you learned how to leverage the built in logging class Log android util Log to implement different levels of diagnostic logging You can monitor the output of log information from within Eclipse or by
512. urces for easy localization A cancel listener is added This allows the user to press the back button to cancel the dialog When this happens the AsyncTask cancel method is called This means that cancelling the dialog will now cancel the task which will cancel the network activity Downloading and Parsing Question Batches 273 Handling the Background Processing Now you need to identify what processing should run asynchronously Again this is the downloading and parsing code The following code with exception handling removed for clarity shows how to override the doInBackground method Override protected Boolean doInBackground String params boolean result false startingNumber Integer params 1 String pathToQuestions params Q max QUESTION_BATCH_SIZE amp start startingNumber result loadQuestionBatch startingNumber pathToQuestions return result Here the background processing simply involves determining the appropriate ques tion batch to download and calling the helper method loadQuestionBatch This method must be moved into the QuizTask class and updated to contact the applica tion server Again this is simply a matter of generating the appropriate URL open ing the stream to the remote application server and using the setInput method of Xm1PullParser For the full code to the implementation please see the sample code provided on By a this book s website ay
513. urs In the following example exception handling has been removed for clarity and brevity The only interesting method here is doInBackground which communicates player settings to the application server Override protected Boolean doInBackground Object params Boolean succeeded false Integer playerId mGameSettings getInt GAME_PREFERENCES_PLAYER_ID 1 String nickname mGameSettings getString GAME_PREFERENCES_NICKNAME String email mGameSettings getString GAME_PREFERENCES EMAIL String password mGameSettings getString GAME_PREFERENCES_PASSWORD Integer score mGameSettings getInt GAME_PREFERENCES_ SCORE 1 Integer gender mGameSettings getInt GAME_PREFERENCES_GENDER 1 Long birthdate mGameSettings getLong GAME_PREFERENCES DOB 0 String favePlaceName mGameSettings getString GAME_PREFERENCES_FAV_PLACE_NAME Vector lt NameValuePair gt vars new Vector lt NameValuePair gt if playerId 1 TelephonyManager telManager 283 FIGURE 16 1 Using an inde terminate progress indica tor in the top right of the menu bar faint circle 284 HOUR 16 Adding More Network Support TelephonyManager getSystemService Context TELEPHONY SERVICE String uniqueId telManager getDeviceld vars add new BasicNameValuePair uniquelId uniqueld else vars add new BasicNameValuePair updateld playerId toString vars add new BasicNameValue
514. use social features and third party social networking sites to improve the game experience for users Enhancing Your Application with Social Features The Been There Done That application has really taken shape over the past few hours However it s not terribly fun to play a game all alone Ideally users want to be able to share the game experience with other players Applications that allow some sort of user interaction are more likely to become viral and more popular thus ensuring success Social applications can be roughly divided into two categories those that are designed to access social networks such as MySpace or Facebook directly and applications that use social information to enhance the user s game experience The Been There Done That game is ideal for this latter use 292 HOUR 17 Adding Social Features Tailoring Social Features to Your Application Determining what social and interactive features to build into your application can be tricky business As an application designer you might ask yourself questions like the following gt What social features if any make sense in my application Will the applica tion use social features to encourage competition high score comparisons notifications when a friend surpasses the user s high score and so on Will the application use social networking features to broadcast game activity post game wins to Facebook or a Twitter feed and thus enable free promotional
515. ust find other mechanisms in you re interested in recurring payment pricing Note that the Android Market currently imposes a 30 transaction fee for hosting applications within the Android Market Prices 400 Oat Di tow HOUR 24 Publishing on the Android Market can range from 0 99 to 200 USD and similar ranges are available in euros and UK pounds gt Copy protection information Choosing this option may help prevent the application from being copied from the device and distributed without your knowledge or permission gt Support contact information This option defaults to the information you provided for the developer account You can change it on an app by app basis though which allows for great support flexibility when you re publish ing multiple applications gt Consent You must click the checkboxes to agree to the terms of the current at the time you click Android Content Guidelines as well as the export laws of the United States regardless of your location or nationality Be sure to carefully read the details pages follow the Learn More link for the export compliance rules There Google also links to a couple of U S government web pages that provide enough information to know if you ll run afoul of these laws The application package is uploaded and verified while you fill out the form Once an application package has been successfully uploaded the previous infor mation can be saved a
516. ut Answers 1 False Use the clearAnimation method to clear all pending and executing animations on a given view 2 B Tweened animation can include any combination of alpha transitions transparency scaling growth or shrinking two dimensional rotation and translation moving from one point to another 3 True In addition LinearLayout can be used for all child View objects to draw to the left and right of each other horizontal 4 Band C FrameLayout and RelativeLayout are both included in the Android SDK Exercises 1 Modify LayoutAnimationController to apply animations of each child view within a TableRow control in random order by using the setOrder method with a value of 2 random 2 Modify LayoutAnimationController to apply animations to each child view within a TableLayout control instead of each TableRow control View the resulting animation 3 Modify the splash screen layout to play a short video instead of animating the ImageView controls First replace the TableLayout control with a VideoView control Then set the URI of VideoView to the URL of a web video in the appropriate format using the Uri parse method and the VideoView con trol s setVideoURI method Finally remove AnimationListener and use a VideoView control s OnCompletionListener instead to transition to the main menu screen when the video completes This page intentionally left blank HOUR 8 Implementing the Main Menu Scree
517. ut control with two ImageView controls and a TextView con trol Set the TextView control s text attribute to the string resource called string help to reflect the appropriate screen title 3 Outside the RelativeLayout control but still within the LinearLayout con trol add a TextView control called TextView_HelpText Set its layout_width attribute to fill_parent and its layout_height attribute to fill_parent You can automatically link phone numbers web addresses email addresses and postal addresses that show in the TextView control to the Android Phone Dialer Web Browser Email and Map applications by setting the linksClickable attri bute to true and the autoLink attribute to all for the TextView control At this point save the help xm1 layout file You can make TextView control text bold or italic by using the textStyle attribute Working with Files Working with Files Now that the help xml layout file is complete you need to update the QuizHelpActivity class to read the quizhelp txt file and save the resulting text into the TextView control called TextView_HelpText Adding Raw Resource Files Raw resource files such as the quizhelp txt text file can be added to the project by simply including them in the raw resources project directory This can be done by either creating them as a new file dragging them in from a file management tool or any other way you re accustomed to adding files t
518. ute set to drawable bkgrnd All subsequent controls will be added inside the LinearLayout control 2 Add the same title bar controls you ve added to other screens 3 Below the title bar add a Scroll1View control to encapsulate your settings Set its isScrollContainer attribute to true and its scrollbars attribute to ver tical Set its layout_width and layout_height attributes to fill_parent 4 Within the ScrollView control add a LinearLayout control to encapsulate your settings Set its orientation attribute to vertical Set its layout_width Using Common Form Controls 167 and layout_height attributes to fill_parent All subsequent controls will be added within this LinearLayout control 5 Within the LinearLayout control add a TextView control to display the Nickname label text Below the TextView control for the label add an EditText control Set its id attribute to EditText_Nickname its maxLength attribute to 20 its maxLines attribute to 1 and its inputType attribute to textPersonName 6 Add a TextView control to display the Email label text Then add another EditText control below it setting its id attribute to EditText_Email its maxLines attribute to 1 and its inputType attribute to textEmailAddress 7 Add the Password settings region of the form by adding another TextView control to display the Password label text Below it add a horizontal LinearLayout control with two controls a Button control and a TextView
519. util package as well as additional specialized classes in the android util package You can instantiate the Hashtable member variable in the onCreate method of the QuizGameActivity class as follows mQuestions new Hashtable lt Integer Question gt QUESTION_BATCH_SIZE Now assuming we have some XML representing a new batch of questions we can create an XmlResourceParser object called questionBatch The XmlResourceParser can be used it to extract the data for each question and save into a Hashtable member variable of type Question using the put method like this String questionNumber questionBatch getAttributeValue null XML_TAG_QUESTION_ATTRIBUTE_NUMBER Integer questionNum new Integer questionNumber String questionText questionBatch getAttributeValue null XML_TAG_QUESTION_ATTRIBUTE_TEXT String questionImageUrl questionBatch getAttributeValue null XML_TAG_QUESTION_ATTRIBUTE_IMAGEURL Save data to our hashtable mQuestions put questionNum new Question questionNum questionText questionImageUr1 You can check for the existence of a specific question in the Hashtable member variable by question number using the containsKey method You can also retrieve a specific Question object by its question number by using the get method Question curQuestion Question mQuestions get questionNumber Wiring Up Game Logic 211 Handling Button Presses The Button controls on the game s
520. veDialog method is called explicitly Q How can I determine which activity launched a Dialog control A You can use the getOwnerActivity method of the Dialog class to deter mine the parent activity of a specific Dialog control Workshop Quiz 1 What class can be used to create pop up windows within an activity A Popup B ActivityWindow C Dialog True or False You can use the same dialog for multiple uses if the layout is the same True or False Only certain layouts can be used with a dialog such as Alert and ContinueOrCancel Workshop 195 Answers 1 C The Dialog class and its subclasses are used to create pop up windows within an activity using the onCreateDialog and showDialog methods 2 True But if you want the data shown to be different you need to override onPrepareDialog in the activity 3 False You can use any layout you want for a dialog Exercises 1 Update the DatePickerDialog onDateSet method to save the date of birth to a TextView to display on the main settings screen 2 Update the password dialog to display the status of the password set or unset in a TextView on the main settings screen This page intentionally left blank HOUR 12 Adding Application Logic What You l Learn in This Hour Designing the game screen Working with ViewSwitcher Controls Data structures and parsing XML gt gt gt gt Wiring up the game logic and keeping game
521. vices The list this command returns includes any emulators or handsets attached to the computer The results might look like this adb devices List of devices attached emulator 5554 device HT9CSP801234 device You can then target a specific device on which to install the application package file by using the s option For example to install the BeenThereDoneThat apk appli cation package file on the emulator you use the following adb s emulator 5554 install BeenThereDoneThat apk For more information about the adb command line tool see the website http developer android com guide developing tools adb html Verifying the Signed Application You re almost done Now it is time to perform a few last minute checks to make sure the application works properly gt Verify smooth installation of the signed application package gt Verify that all debugging features have been disabled gt Verify that the application is using the live services as opposed to any mock services gt Verify that application configuration data such as the application name and icons as well as the version information displays correctly If you find any issues with the signed application functionality you must decide whether they are serious enough to stop the release process and begin again Once you ve tested the application package thoroughly and are confident that users will have a positive experience using your application you are
522. vity Derived from QuizActivity this class represents the help screen gt QuizScoresActivity Derived from QuizActivity this class represents the scores screen gt QuizSettingsActivity Derived from QuizActivity this class represents the settings screen gt QuizGameActivity Derived from QuizActivity this class represents the game screen FIGURE 6 1 A rough design of the activity workflows in the Been There Done That application Determining Screen Specific Game Features Now it s time to define the basic features of each activity in the Been There Done That application Defining Splash Screen Features The splash screen serves as the initial entry point for the Been There Done That game Its functionality should be encapsulated within the QuizSplashActivity class This screen should do the following gt Display the name and version of the application gt Display an interesting graphic or logo for the game gt Transition automatically to the main menu screen after a period of time 98 FIGURE 6 2 The Been There Done That splash screen HOUR 6 Designing an Application Framework Figure 6 2 shows a mockup of the splash screen Version 1 0 0 Copyright 2010 Mamlambo Inc All Rights Reserved Defining Main Menu Screen Features The main menu screen serves as the main navigational screen in the game This screen displays after the splash screen and requires the user to choose
523. way or two way showing up on one or both players Friends lists Different trust relationships could be established allow ing players access to different types of information about other players including friends answers to questions and their favorite place in the world 300 HOUR 17 Adding Social Features gt After a friend relationship has been established more application features could be added including challenges messaging notifications the sky s the limit Use your imagination The complete implementation of the friends feature as described in this hour may seem incomplete and it is Any application incorporating a similar friends features should at minimum allow the player to manage for example view delete his or her existing friend relationships However these improvements are left as exercises for the reader Integrating with Social Networking Services Social networking has really come into its own in the past few years allowing peo ple to connect keep in touch and share information for better or worse about their lives Many social networking sites have developed APIs for third party devel opers many of which are web services based on representational state transfer REST There has been an explosion in the number of applications available for social networks such as Facebook Android applications can integrate with a social networking site through develop ment programs and the API provided b
524. where to go next Its functionality should be encapsulated within the QuizMenuActivity class This screen should do the following gt Automatically display after the splash screen gt Allow the user to choose Play Game Settings Scores or Help Figure 6 3 shows a mockup of the main menu screen Defining Help Screen Features The help screen tells the user how to play the game Its functionality should be encapsulated within the QuizHelpActivity class This screen should do the following gt Display help text to the user and enable the user to scroll through text gt Provide a method for the user to suggest new questions Designing an Android Trivia Game 99 FIGURE 6 3 The Been There Done That main menu screen FIGURE 6 4 The Been There Done That help HelScreen 25 screens Have you been there Have you done that fall G 8 19pm BEEN THERE DONE TRAT is atrivia quiz dedicated to those Who love travel and adventure By answering a series of Yes or No questions you gain points toward being the most well travel d and field tested person bn the planet Share your experiences and compete with your friends ri GAME SEJTINGS _ lt TBD gt SUPPORT INFORMA TION 5 100 FIGURE 6 5 The Been There Done That scores screen HOUR 6 Designing an Application Framework Defining Scores Screen Features The scores screen allows the user to view game scores Its fu
525. ws TextSwitcher questionTextSwitcher TextSwitcher findViewById R id TextSwitcher_QuestionText questionTextSwitcher setText getResources getText R string no_questions ImageSwitcher questionImageSwitcher ImageSwitcher findViewById R id ImageSwitcher_QuestionImage questionImageSwitcher setImageResource R drawable noquestion 213 FIGURE 12 4 The Been There Done That game screen 214 Adding Application Logic You should also take this opportunity to disable the Button controls Button yesButton Button findViewById R id Button_Yes yesButton setEnabled false Button noButton Button findViewById R id Button_No noButton setEnabled false When the application runs out of questions the game screen looks as shown in Figure 12 5 The user is informed that there are no more questions available and is not allowed to press any of the Button controls Instead the user must press the Back button and return to the main menu FIGURE 12 5 The Been There peer There Dene Done That nren ere Done That game screen lt p when no ee f questions are available No more questi ns available Try back later gt Summary In this hour you implemented the most important screen of the Been There Done That application the game screen You learned how to animate between View controls by using ImageSwitcher and TextSwitcher You also got your first look at the various data structures available in the A
526. y To have full multipart MIME support in the Been There Done That applica tion you need to add all three JAR files listed earlier These packages also add some other interesting utilities such as the I0Utils class which provides a number of handy methods for dealing with data streams A 288 HOUR 16 Adding More Network Support Creating an AsyncTask Class to Handle Avatar Uploads To upload the avatar graphic to the application server you need to add another AsyncTask subclass called ImageUploadTask to the QuizSettingsActivity class The ImageUploadTask class can be run using the execute method whenever the player sets a new avatar on the settings screen The details of the ImageUploadTask class are very similar to those of the other AsyncTask subclasses you have written over the past two hours The only really interesting part to this new task is the avatar file handling code needed within the doInBackground method exception handling removed for clarity and brevity Override protected Boolean doInBackground Object params String avatar mGameSettings getString GAME_PREFERENCES_AVATAR Integer playerId mGameSettings getInt GAME_PREFERENCES_PLAYER_ID 1 MultipartEntity entity new MultipartEntity HttpMultipartMode BROWSER_COMPATIBLE File file new File avatar FileBody encFile new FileBody file entity addPart avatar encFile entity addPart updateId new StringBody playerId toStrin
527. y as shown here Override protected void onPause if allScoresDownloader null amp amp allScoresDownloader getStatus AsyncTask Status FINISHED allScoresDownloader cancel true if friendScoresDownloader null amp amp friendScoresDownloader getStatus AsyncTask Status FINISHED friendScoresDownloader cancel true super onPause Downloading and Parsing Question Batches Now that you understand how to download data asynchronously you can use AsyncTask to handle downloading and displaying the question batches on the game screen This process is very similar to the process involved in downloading score data However you will not publish progress as you go instead you will sim ply display a progress bar until all questions in a given batch are downloaded Begin by creating a subclass called QuizTask that extends the AsyncTask class with in the QuizGameActivity class like this private class QuizTask extends AsyncTask lt Object String Boolean gt TODO Implement AsyncTask callback methods You might want to add a custom DEBUG_TAG member variable to the QuizTask By the class This allows you to differentiate between debugging information from the ay background thread and UI thread 272 HOUR 15 Adding Network Support The QuizTask class also needs member variables for the starting question number and a ProgressDialog to display background processing progress to the
528. y if all the settings fields do not fit on a screen the user can scroll The ScrollView control can have only a single child control so you can encapsulate the bulk of your settings in another vertical LinearLayout control Each setting requires two rows in the LinearLayout control a TextView row that displays the setting name label and a row for the input control to capture its value For example the Nickname setting would require a row with a TextView control to display the label string Nickname and a row for an EditText control to allow the user to input a string of text Now you need to determine which control is most appropriate for each setting gt The Nickname and Email fields are simply different types of single line text input so they can be EditText controls gt The Password setting requires two EditText controls However the Password text need not be displayed on the settings screen directly Instead you create a Button control to launch a Dialog window to allow the user to change the password using the two EditText controls The main settings screen can just display whether a password has been set in a TextView control gt The Date of Birth setting requires a DatePicker control Because the DatePicker control is actually three separate controls a month picker a day picker and a year picker it takes up a lot of space on the screen Therefore instead of including it directly on the screen you can ad
529. y java class file and add a click listen er and a long click listener to the ImageButton_Avatar control 2 Within the onClick method of OnClickListener add a Toast message that says Short click 3 Within the onLongClick method of OnLongClickListener add a Toast message that says Long click 4 Save your work and re launch the application Click the avatar ImageButton control on the settings screen and note when click and long click events occur A Working with Image Media Now that you have the avatar ImageButton control configured you can work on handling the user click actions When the user clicks the avatar button you want to launch the appropriate activity via Intent and then handle the resulting image and set it as an avatar 224 HOUR 13 Working with Images and the Camera For now you can save the avatar image locally on the handset You also need to add a new preference to the application SharedPreferences You begin by defining this new preference in the QuizActivity java class as follows public static final String GAME_PREFERENCES_AVATAR Avatar Launching Activities and Handling Results If you think back to Hour 3 Building Android Applications when we talked about application life cycle you will recall that there are several ways to launch an activi ty Specifically there is a method called startActivityForResult that allows you to launch an activity using an intent and then handle the re
530. y platforms as possible Lately we ve been finding that the answer is the Android platform It s inexpensive and easy to develop for it s available to millions of potential users worldwide and it has fewer limitations than other platforms Still the Android platform is relatively young and has not yet reached its full fledged poten tial This means frequent SDK updates an explosion of new devices on the market anda nearly full time job keeping track of everything going on in the Android world In other words it may be a bit of a bumpy ride but there s still time to jump on this band wagon write some kick butt applications and make a name for yourself So let s get to it 2 Introduction Who Should Read This Book There s no reason anyone with an Android handset and a good idea for a mobile application couldn t put this book to use for fun and profit Whether you re a programmer looking to break into mobile technology or an entrepreneur with a cool app idea this book is for you We make very few assumptions about you as a reader of this book You may have a basic understanding of the Java programming language understanding classes methods basic inheritance and so on but Android makes a fantastic platform for learning Java as well We have avoided using any fancy or confusing Java in this book so if you re just getting started with programming you should be able to read the first few chapters of any intro
531. y source they choose Keep in mind such device differences when provid ing instructions for users 403 FIGURE 24 5 The Application Settings screen showing the set ting for down loading from unknown sources 404 Di tow HOUR 24 Publishing on the Android Market Selling Your Application Using Other Alternatives The Android Market is not the only consolidated market available for selling Android applications Because Android is an open platform there is nothing pre venting a handset manufacturer or an operator or even you from running an Android marketplace website or building an Android application that serves as a market Here are a few marketplaces where you might consider distributing your Android applications gt PocketGear This site distributes mobile applications across a wide range of devices using various billing models http www pocketgear com gt SlideME This is an Android specific distribution community for free and commercial applications using an on device store http slideme org gt AndAppStore This site offers Android specific distribution for free applica tions using an on device store http www andappstore com gt SHOP4APPS This application store run by Motorola targets China http developer motorola com shop4apps gt MobiHand This site distributes mobile applications for a wide range of devices for free and commercial applications http www mobih
532. y the specific site or service The level of inte gration may range from lightweight to complete Here are some examples of social networking integration you could consider in an Android application gt Giving the user the option to automatically tweet on Twitter when he or she wins a game gt Writing an application that allows the user to view and update his or her per sonal blog Twitter feed and Facebook status gt Developing a fully featured Twitter client application In each case Twitter features are integrated into the Android application in different ways Now let s look at adding support for some of the social networking services that are popular today Adding Facebook Support Facebook is a popular social web service where people can connect share pictures and video and chat Facebook provides a portal for developers who want to Integrating with Social Networking Services 301 integrate Facebook functionality into third party applications at http developers facebook com You can find out more about the Facebook Platform for Mobile Facebook Connect Facebook SMS and so on at http wiki developers facebook com index php Mobile Adding Twitter Support Twitter is a popular social networking service where people share short text mes sages called tweets Each tweet is only 140 or fewer characters making Twitter an ideal platform for mobile Twitter provides a portal for developers with reference information
533. you must first retrieve it by using the findViewById method as follows ListView menuList ListView findViewById R id ListView_Menu Next you need to define the String values you will use to populate the TextView items within the ListView control In this case you will load the four resource strings representing the choices String items getResources getString R string menu_item_play getResources getString R string menu_item_scores getResources getString R string menu_item_settings getResources getString R string menu_item_help Now that you have retrieved the ListView control and have the data you want to stuff into it you need to use a data adapter to map the data to the layout template you created menu_item xml The choice of adapter depends on the type of data being used In this case you use ArrayAdapter ArrayAdapter lt String gt adapt new ArrayAdapter lt String gt this R layout menu_item items Next you need to tell the ListView control to use the adapter menuList setAdapter adapt At this point you can save the QuizMenuActivity java file and run the Been There Done That application in the Android emulator After the splash screen fin ishes the main menu screen should look much like the screen shown in Figure 8 3 Working with the ListView Control 135 n FIGURE 8 3 Gail 8 41 pm The Been There ADoneltt Done That y MAIN MENU Py splash screen If you get
534. you need to add a special type of resource called a menu resource You can then change QuizGameActivity class to enable an options menu and handle menu selections Adding Menu Resources For your options menu you create a menu definition resource in XML and save it to the res menu resource directory as gameoptions xml A menu resource contains a lt menu gt tag followed by a number of lt item gt child ele ments Each lt item gt element represents a menu option and has a number of attrib utes The following are some commonly used attributes gt id tThis attribute allows you to easily identify the specific menu item gt title This attribute is the string shown for the options menu item gt icon This is a drawable resource representing the icon for the menu item Your options menu will contain only two options Settings and Help Therefore your gameoptions xml menu resource is fairly straightforward Working with Other Menu Types lt menu xmlns android http schemas android com apk res android gt lt item android id id settings_menu_item android title string menu_item_settings android icon android drawable ic_menu_preferences gt lt item gt lt item android id id help_menu_item android title string menu_item_help android icon android drawable ic_menu_help gt lt item gt lt menu gt You set the title attribute of each menu option by using the same String resources you used on t
535. you will want to update the onCreate method of the QuizScoresActivity class to call the ScoreDownloaderTask class s execute method when the screen first loads The execute method takes two parameters the server web address and the table to populate with scores a TableLayout control public static final String TRIVIA_SERVER_BASE http tqs mamlambo com public static final String TRIVIA_SERVER_SCORES TRIVIA_SERVER_BASE scores jsp ED vais allScoresDownloader new ScoreDownloaderTask allScoresDownloader execute 7TRIVIA_SERVER_SCORES allScoresTable SharedPreferences prefs getSharedPreferences GAME_PREFERENCES Context MODE_PRIVATE Integer playerId prefs getInt GAME_PREFERENCES_PLAYER_ID 1 if playerId 1 friendScoresDownloader new ScoreDownloaderTask friendScoresDownloader execute TRIVIA_SERVER_SCORES playerId playerId friendScoresTable Now that you have set up the ScoreDownloaderTask class you can focus on imple menting the AsyncTask callback methods appropriately Don t worry about the player Id value just yet We ll discuss that next hour By fhe 268 HOUR 15 Adding Network Support Starting the Progress Indicator Next you need to implement the onPreExecute method which runs on the UI thread before background processing begins This is the perfect place to demonstrate adding to the title bar an indeterminate progress indicator Overr
536. yout_alignParentTop attributes to true Find the ImageView control with the id attribute set to ImageView_Header2 and set its layout_alignParentRight and layout_alignParentTop attrib utes to true Find the ImageView control with the id attribute set to ImageView_Header3 and set its layout_alignParentLeft and layout_alignParentBottom attrib utes to true Find the ImageView control with the id attribute set to ImageView_Header4 and set its layout_alignParentRight and layout_alignParentBottom attributes to true Still within the RelativeLayout control add another RelativeLayout control for the trivia question region after the ImageView control name it ImageView_Header2 Set its id attribute to the value id RelativeLayout_Content Set layout_width to wrap_content and layout_height to wrap_content Also set its gravity attribute to center and its layout_margin to 45px Working with ViewSwitcher Controls 203 9 Within the new RelativeLayout control add an ImageSwitcher control with an id of id ImageSwitcher_QuestionImage Set layout_width to wrap_content and layout_height to wrap_content Also set its layout_alignParentTop and layout_centerInParent attributes to true 10 Below the ImageSwitcher control add a TextSwitcher control with an id of id TextSwitcher_QuestionText Set layout_width to wrap_content and layout_height to wrap_content Also set its layout_centerInParent attrib ute to true and its layout_below attribute to

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