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VisualAge for Smalltalk Handbook Volume 1

1. 0 2 127 Access to Container Object Attribute 0 2020 0 128 Removing an Icon e 128 Error Attribute Does Not Exist 024 129 Adding an Icon to A List Part aaa aaa 129 Drag and Drop s bosd oo e g 4046 eet ee or Se eR EY 129 Multiline Text 224 2 8 e4 no 280 6 eek Bee Se Dee he ta hea 130 WindowoTitles 2444 32 4 45644 eden dorar bee ad 131 Querying the Caret Position in Text 131 Color Bitmap Resolution 0 2 00 2000000200 131 Automatic Tab Moving aoaaa aaa ee 132 User Input Error locaciones ee 133 Closing the Window 2 aa 134 Transparent Background 0 20020 0554 135 Getting the Anchor Block Handle 135 Turning Off Error Message 00 000 00 pee 135 Locating the Focus 2 5 4 5 44 e058 ed ee a a 136 Bitmaps on Buttons 0 020000 2 ee 136 Progress Indicator Window 200544 137 HotSpots altea chen amp it Gee dye ko Ga hee oe oe Ges 138 SAA E A Se ofertas eae A aay oot 138 WallPaper iras ad Cute ee eee eRe I Pa ee RS 138 Labels on Message Prompter 20 0 20005 139 Visual Part Reuse ect a Bal la RE oo oe 140 Supported Image Formats 2 000002 eee 140 Click Sensitive Bitmap 0 02000002 pee 140 Seting Help 25 a A Se Ae ede tele Ged ep iota Bees e we Aan 141 Modifying Data Entry Parts 0 0 o 141 Re
2. classCollection Set new appCollection Set new catFiles Set new mprFiles Set new spusageFile spusage es asFileSpec fileStream spusageFile cfsStreamReadOnlylfError aCfsErr aCfsErr printString fileStream skipToAll Output statistics for ifTrue icxFileName fileStream nextLine fileStream skipToAll Size Size Size ifTrue fileStream nextLine nextLine fileStream atEnd whileFalse class fileStream upTo isEmpty ifTrue fileStream setToEnd ifFalse classCollection add class asClass fileStream nextLine fileStream close classCollection do eachClass app app eachClass controller appCollection add app rootApplication appCollection do eachApp poolNames mprName poolNames eachApp definedPoolNames poolNames do eachPoolName pool catName pool Smalltalk at eachPoolName ifAbsent eplsPoolDictionary ifTrue catName pool at CATALOGNAME ifAbsent isNil ifFalse catFiles add catName cat mprName eachApp abtNisRawFilename isEmpty ifFalse mprFiles add AbtNLSCoordinator resolveLanguageMappingCharacter mprName Chapter 2 General Information 79 Smalltalk continued work Transcript bringToFront work cr nextPutAll The required message files for icxFileName cr cr nextPutAll Cat files cr catFiles isEmpty ifTrue wor
3. API See application program interface APPC See Advanced Program to Program Communication application 1 The use to which an information processing system is put for example a payroll application or an order entry application 2 A collection of defined and extended classes that provides a reusable piece of functionality An application contains and organizes functionally related classes It also can contain subapplications and specify prerequisites application layer In Open Systems Architecture the layer of the OSI reference model that provides a means for application processes residing in different open systems to exchange information application manager 1 A team member who is responsible for the overall state of an application An application manager coordinates the activities of the application s developers and assigns ownership of classes to team members 2 The browser from which users can create delete manage or configure applications in their image application program 1 A program written for or by a user that applies to the user s work Some application programs receive support and services from a special kind of application program called a network application program 280 VisualAge for Smalltalk Handbook Fundamentals 2 A program used to connect and communicate with stations in a network enabling users to perform application oriented activities Note Do not use the term applicat
4. How to Get ITSO Redbooks This section explains how both customers and IBM employees can find out about ITSO redbooks CD ROMs workshops and residencies A form for ordering books and CD ROMs is also provided This information was current at the time of publication but is continually subject to change The latest information may be found at URL http www redbooks ibm com How IBM Employees Can Get ITSO Redbooks Employees may request ITSO deliverables redbooks BookManager BOOKs and CD ROMs and information about redbooks workshops and residencies in the following ways PUBORDER to order hardcopies in United States GOPHER link to the Internet type GOPHER WTSCPOK ITSO IBM COM Tools disks To get LIST3820s of redbooks type one of the following commands TOOLS SENDTO EHONE4 TOOLS2 REDPRINT GET SG24xxxx PACKAGE TOOLS SENDTO CANVM2 TOOLS REDPRINT GET SG24xxxx PACKAGE Canadian users only To get BookManager BOOKs of redbooks type the following command TOOLCAT REDBOOKS To get lists of redbooks type one of the following commands TOOLS SENDTO USDIST MKTTOOLS MKTTOOLS GET ITSOCAT TXT TOOLS SENDTO USDIST MKTTOOLS MKTTOOLS GET LISTSERV PACKAGE To register for information on workshops residencies and redbooks type the following command TOOLS SENDTO WTSCPOK TOOLS ZDISK GET ITSOREGI 1996 For a list of product area specialists in the ITSO type the following command TOOLS SENDTO WTSCPOK TOOLS ZDISK GET ORGCARD PACK
5. 214 Smalltalk featuresAffectedByAction actionName For objects that do not signal their own change events Defines the features affected by an action Do not signal any events the receiver handles all change events itself Smalltalk featuresAffectedByAttributeChange attributeName For objects that do not signal their own change events Do not signal any events the receiver handles all change events itself For both methods the code has been replaced by the simple return of an empty array indicating that no change events need to be signaled For both methods answering an array containing self a Symbol signals change events for all the receiver s features Be warned that with these methods overridden you have the responsibility for triggering all events yourself VisualAge will do nothing for you automatically If you have an attribute that is an OrderedCollection for example and you add an object to that OrderedCollection in a method or script you have to trigger the changed event for that collection yourself The ToDoList class subclass of Object keeps a list of things to do in an OrderedCollection in an attribute named ist The action addToList invokes the method addToList Smalltalk addToList aString Adds a string to the receiver s list self list add aString self signalEvent list with self list The last line of th
6. Chapter 3 Graphical User Interface 95 a form part or in a group box and offset the controls from each other and the sides of the form or group and then offset the forms and group boxes Setting Minimum Window Size Answer How can you set or specify the minimum size for a window The following script checks after each window resize whether it has exceeded a predefined minimum size If so it sets it to the predefined minimum size Do not forget to connect the resized event of the window to this script Smalltalk checkResize tempWidget minimumWidgetSize minimumWidgetSize 400 200 tempWidget self primaryWidget tempWidget width lt minimumWidgetSize first ifTrue tempWidget width minimumWidgetSize first tempWidget height lt minimumWidgetSize last ifTrue tempWidget height minimumWidgetSize last Closing a Widget from a Script have created a view in which show some customer information from an ordered collection that dropped on the free form also dropped a button and connected it to the following script Smalltalk return Close the widget and return self closeWidget When testing the script the widget closes but a dependent of ordered collection remains in the Dependent dictionary Is this not the proper way of closing a view have noticed that if you close the view by using ALT F4 96 VisualAge for Smalltalk Handbook Fundamentals A
7. Smalltalk 1 abtPadWith 0 upToLength 5 onRight false gt 00001 abc abtPadWith d upToLength 4 onRight true gt abcd Trimming a String Questioni How do trim a string padded with spaces If you want to remove only the leading and trailing spaces use trimBlanks If you want to remove all the white space use abrWithoutWhitespace Inhibiting List Selection Question need to be able to inhibit list selection when users click on specific items within Cw and Ew list widgets but there doesn t seem to be a public interface for doing so know native aboutToChangeSelection events exist down on the GUI platforms I ve implemented them on Windows not sure about OS 2 The documentation I ve read make no mention of any callback return values that could be used towards this end ld like to avoid subclassing or extending classes in OSwidget layer if possible The Ew list widgets EwList and subclasses have a selectionPolicy interface have a look at the comment This should enable you to do what you want Chapter 4 IBM Smalltalk Programming Language 223 Resizable Table Rows Answer l am using VisualAge Professional for OS 2 and WindowBuilder Pro for OS 2 3 0 and am having difficulty trying to use the multiline text edit policy within an EwTableList widget hope someone can come up with a simple solution for what am trying to do We have an interface that is supp
8. Smalltalk AbtTableView gt gt subpartNamed aColName put aColumnView colNdx self components includesKey aColName ifTrue false colNdx self components size 1 self subpartNamed aColName put aColumnView partindex colNdx Chapter 3 Graphical User Interface 147 Smalltalk AbtTableView gt gt suggestedNewColumnWidth Use this method when adding new columns dynamically at runtime to prevent the new column from being too small ans self components size 0 ifTrue 1 ans 9999999999 self components do col ans ans min col ratioWidth ans N Smalltalk AbtTableColumnView gt gt openWidget Public Category AbtRun Internal pv pv self parentView nil ifTrue self pv setUpWidget Synchronize Table Scrolling Question Is there any way of synchronizing the scrolling of two tables in the same window would like to move the vertical scroll bar of one table and have the scroll bar of the other table move in the same way To synchronize the scrolling of two tables you will have to use callbacks The slider bar is a CwScrollBar widget Callbacks can be specified for the various slider requests for example moving the slider clicking on the arrows Each callback method will have to scroll the second table For example suppose you set up an increment callback for table A The method specified for this callback gets c
9. You can store a code string to be evaluated with YourApplication toBeLoadedCode yourcode or bring up a simple editor with YourApplication abtEditToBeLoadedCode The TrailBlazer can modify these directly by selecting an application Browse Applications and changing the lower pane property to ToBeLoadedCode Forking and Cycles Answer have an application in which display a window containing a graphic that through the use of a timer appears to move That is the users see an image move across the window to illustrate that information is being downloaded from a database To do this have used fork forkAt and a number of other techniques The problem is that cannot get the graphic moving smoothly while the domain is initiated When run both pieces of code it appears that the graphics get held up during the actual query call and the instantiation gets held up by the timer The resulting behavior is that the graphics appear but don t move until the query has finished Would this be the right approach to do this Getting a smooth graphic is difficult when you depend on the scheduling algorithm Instead it would be better to use signaling from the work process to the status process For example for each step through the database table you signal the status process This is often necessary because graphics update runs at the low priority By forcing graphics updates at regular intervals you assure your user is seeing
10. sets the image owner to nil Then save the image and exit VisualAge for Smalltalk When VisualAge for Smalltalk starts you get the who does this image belong to prompt Moving Development Code How do move development code between libraries Chapter 5 ENVY 251 Answer The best way is by creating a new library then exporting a configuration map or applications to the library Exporting requires the parts to be versioned because editions cannot be exported Distributing an Application for OS 2 and AIX Answer How do distribute an application for both OS 2 and AIX clients You must package on the target environment We access a single manager on an AIX machine for all environments using TCP IP and the EMSRV support thus no import export is necessary just a load and package Exporting an Application to a Non LAN PC 252 Answer How do export an application to another PC not attached to a LAN You can create an export file that contains the application that you want to copy to the other VisualAge for Smalltalk workstation Keep in mind the following e The component being exported must be a version e The component version you want to export cannot already exist in the target library If it does already exist in that library the system exports only those components not already there Here s what you do From your source image e Open an Application Manager browser from the transcript Small
11. stream close Decimal Point Representations Questioni Is it possible to change the default decimal point for the current local representation which probably is a comma The following code results in 0 75 if the local representation of a decimal uses a comma Smalltalk Locale current IcNumeric printNumber 3 4 asFloat on Transcript The next code will result in 0 75 and the reason is that the compiler needs to be able to recognize a float from a method named 264 VisualAge for Smalltalk Handbook Fundamentals Smalltalk 3 4 asFloat printOn Transcript When you use printString on a Float you are getting a representation that can be highlighted and evaluated compiled For occasions where you need locale specific output you instead use the printNumber on method Using Multiple National Languages Questioni How do use multiple national languages with VisualAge for Smalltalk See the VisualAge for Smalltalk User s Guide for a complete discussion of how national language support NLS enablement works Adding French Characters to English Questioni How do allow input of French characters in my English application I ve been running Windows 95 lately and for typing French characters use the U S International keyboard layout That maps certain deadkeys such as apostrophe followed by e gives e accent grave I m not certain OS 2 has this same keyboard layout sc
12. yourself EtInspector publicMethods defaultTextMenu Answer the modified textMenu super defaultTextMenu addLine add menuBrowse label Browse add menuFind label Find yourself EtWindow publicMethods menuBrowse Browse the class for the selection selection className selection self targetTextWidget getSelection trimBlanks className Smalltalk classAt selection ifAbsent self evaluateSelectionIn targetTextWidget ifFail self class className inheritsFrom AbtPart ifTrue className editPart ifFalse EtTools browser class on className open Chapter 2 General Information 59 Smalltalk continued menuFind The Find window selection className selection self targetTextWidget getSelection selection isNil ifFalse selection selection trimBlanks AbtApplicationsOrganizerView current find secondaryViews at find ifAbsent nil findText selection EtWorkspace publicMethods defaultTextMenu Answer the modified textMenu super defaultTextMenu addLine add menuBrowse label Browse add menuFind label Find yourself INhaTools class privateMethods runtimeStartUp self abtViewApplicationPackage runtimeStartUp NhaToolsAbtPackage initializeAfterLoad NhaTools initializeAfterLoad NhaTools loaded 60 VisualAge for Smalltalk Handbook Fundamental
13. American Standard Code for Information Interchange this is the world wide standard for the code numbers used by computers to represent all the upper and lower case Latin letters numbers punctuation etc There are 128 standard ASCII codes each of which can be represented by a 7 digit binary number 0000000 through 1111111 atomic 1 Pertaining to the smallest element in a composite object that can be manipulated independently 2 Pertaining to a set of operations performed such that either all the operations performed or none of the operations are performed 3 Pertaining to a set of operations that cannot be interrupted such as a critical section of a parallel program attribute 1 In VisualAge data that represents a property of a part For example a customer part could have a name attribute and an address attribute Attributes enable a part s public interface to give other parts access to its properties An attribute can itself be a part with its own behavior and attributes Compare to event and action 2 Information that describes the characteristics of system objects or program objects attribute to attribute connection A connection from an attribute of one part to an attribute of another part When one attribute is updated the other attribute is updated automatically See also connection attribute to script connection A connection from an attribute of a part to a script The connected attribute receive
14. Open Database Connectivity ODBC support This feature enables you to access data from a variety of databases and file systems which support the ODBC interface Performance improvements through tuning and enhancements to the underlying virtual machine VM up to 5 times faster execution machine code execution for Intel platforms Usability improvements through improved startup consistency in dialogs settings font usage additional parts improved help better and more complete examples Enhanced database parts for greater usability and performance Upgraded IBM Database support for DB2 2 V2 1 with support for user defined functions UDFs user defined types UDTs and binary large objects BLOBs New portable controls notebook container slider and spin button for multiplatform support and portability Portable drag and drop support VBX support Windows only This feature enables you to wrapper existing VBX controls and use them on the VisualAge for Smalltalk palette Multimedia enhancements including kiosk authoring enablement OS 2 and Windows only which includes support for hot spots and scene to scene navigation Chapter 1 What Is VisualAge for Smalltalk 13 e VisualAge for Smalltalk Distributed enables you to develop a VisualAge for Smalltalk application on a single development platform and split the logic of the application to run on multiple execution platforms Facilities are provided for remote debuggin
15. This code is given as is That is it has some drawbacks First when you get to the end you will have to know the number to reset it to We don t have that check in the code above And when it gets to a group of push buttons I m not sure of the behavior it may just go to the first in a group This is a good start however and the concerns mentioned can be checked for in a script User Input Error Question How can I get the userlnputConvertError event to fire if the user does not change an invalid field You must modify the method AbtTextConverterManager gt gt primCommitUserlnput to handle this or run this script using aDateString as an example when losing focus Smalltalk AbtDateConverter new primDisplayToObject aDateString ifError error CwAppContext default asyncExecInUl aView setFocus Chapter 3 Graphical User Interface 133 Closing the Window Question When I press the Esc key the window closes What event is triggered by pressing the Esc key Can capture this event to alter the behavior Yes Connect the shell s closeWidgetRequest event to a script like this Smalltalk myShellCloseWidgetRequest aConfirmationCallbackData aConfirmationCallbackData doit false The window won t close as long as doit is set to false When you use openOwnedWidget as opposed to openWidget you are actually creating a dialog box as opposed to a standard frame window It is the dialog box th
16. e Smalltalk with Style David Thomas et al Prentice Hall e Smalltalk Best Practice Patterns Kent Beck Prentice Hall Chapter 2 General Information 63 64 Class Name Prefix The prefix is arbitrarily defined with the following three characters 1 The first letter stands for the company name 2 The second letter describes the type of components A c M Application Class Configuration map 3 The third letter is used to categorize the component within a layered architecture A Defines classes of the top layer which is the application layer All classes are visual representing the screens of the application At the application layer the primary part of a class is always a window for example an instance of AbtShellView rather than a form an instance of AbtFormView This optional layer contains reusable visual classes The main difference between this layer and the application layer is the fact that the primary part of a class is always a form rather than a window The model layer contains the implementation of the object model reflecting the business domain of the enterprise As part of the infrastructure the GUI layer contains classes that provide additional features to the base product such as converters security defined at the widget level controller services common to any instances of Model View Controler MVC or a window manager that keeps track of the view that owns the current unit of work
17. 0 000000 02000 249 Loading Previous Editions of Application 249 Deleting an Application 0 2 0 0 a 249 Creating a New Application 2 02 00200 250 Removing an Application 2 0 0 0 0000 2 ee 250 Deleting Old Versions of Classes 250 Getting Rid of Damaged Classes 251 Prompting for Ownership 2 0 0202004 251 Moving Development Code 00 251 Distributing an Application for OS 2 and AIX 2 252 Exporting an Application to a Non LAN PC 2 2 252 Associating DAT files with Features 2 o o 253 Manager Consistency o 253 Exporting a Pool Dictionary 020202000 254 Exporting Configuration Maps 200 0020 0005 254 Manager Growth Rate 2 2 0 2000000000000 254 Class Changes versus Alternatives 255 Moving Windows Library to AIX 0 0 0 a 255 Identical Users cima e aa o e ve ida 256 Classes Available in the Library oaaao 257 ENVY Windows95 Novell 20 o 257 Chapter 6 Microsoft Windows 259 Sizing the Windows 95 Toolbar 2 2 2 259 Windows 95 TreeView o 259 Deactivation of OLE Embedded WordPro Document 260 Copying from Windows Explorer into an OLE Client Part 260 Generating OLE Method
18. Caching the itemPosition value for performance currentPosition currentPosition callData itemPosition callData selectedltemPositions includes currentPosition ifTrue self lastltemSelected currentPosition Default Action Requested Questioni How do get an event that could work as the DefaultActionRequested available in a text part for a combo box This question indicates an apparent oversight and I ve opened DCR 6872 for a future release In the meantime you can add an activate callback to the widget For example hooked the following code to the combo box s openedWidget event Smalltalk addComboBoxActivateCallback aComboBoxView aComboBoxView widget addCallback XmNactivateCallback receiver self selector myComboBoxDefaultAction clientData callData clientData nil The myComboBoxDefaultAction clientData callData will be invoked when the user presses Enter Or if you prefer you could create a subclass of AbtComboBoxView that adds the new event See also AbtAbstractTextView for an example especially the methods postCreationInitialization Chapter 3 Graphical User Interface 113 defaultActionEvent and defaultAction clientData callData suspect they could be copied to your subclass with only minor modification and the addition of the defaultEventRequested to the public interface of course For an Multiline Edit MLE part the activate callback for CwText applies only when it is
19. In the VisualAge Composition Editor the strip of icons along the top of the free form surface The tool bar contains tools to help construct composite parts These tools are also available through the Tools pull down menu of the Composition Editor window transaction 1 In client server transaction processing a business activity or set of activities that transforms a database from one state to another for example making an airline reservation or custom ordering an automobile 2 In an SNA network an exchange between two programs that usually involves a specific set of initial input data that causes the execution of a specific task or job Examples of transactions include the entry of a customer s deposit that results in the updating of the customer s balance and the transfer of a message to one or more destination points transaction program A program that processes transactions in or through a logical unit LU type 6 2 in an SNA network Application transaction programs are end users in an SNA network they process transactions for service transaction programs and for other end users Service transaction programs are IBM supplied programs that typically provide utility services to application transaction programs Transcript window The main controlling window in Smalltalk Transmission Control Protocol Internet Protocol TCP IP A set of protocols that allow cooperating computers to share resources across a heterog
20. Now was timing the code on VisualWorks 2 0 The first method with become resulted in 396 464 460 the second method came back with 56 52 The ratio here is roughly 400 50 or 8 1 Finally timed the test on Smalltalk V MAC The result of the first version were 9617 6917 8100 8417 The second method resulted in 183 183 183 The ratio is roughly 7000 180 or roughly 40 1 In conclusion IBM and Digitalk got 100 1 and 40 1 which indicates considerable slowness is involved VisualWorks gave only 9 1 which is a lot faster One would suspect the wizards are using different spells but which ones Isn t 100 1 too fast for a search of the whole world Isn t 9 1 too slow for a simple indirection don t know to Method Answer What does the Number class gt gt to do get to do and understand what this does but what is this plain to The to message answers an instance of a collection named Interval Smalltalk 1 to 10 is equivalent to Smalltalk Interval from 1 to 10 and is equivalent to Smalltalk Interval from 1 to 10 by 1 Chapter 4 IBM Smalltalk Programming Language 189 Intervals act like collections if you read from them but they cannot be modified Further they are not stored as collections so that 1 to 1000000 doesn t take any more space than 1 to 10 For example you can write loops just as with any other kind of collection Smalltalk Interval from 1 to
21. One of the methods used in HTTP requests A GET request is used to retrieve data from an HTTP server See also POST GIF Graphics Interchange Format A graphics file format that is commonly used on the Internet to provide graphics images in Web pages global variable A variable that any method in any object can access graphical user interface GUI A type of interface that enables users to communicate with a program by manipulating graphical elements rather than by entering commands Typically a graphical user interface includes a combination of graphics pointing devices menu bars overlapping windows and icons graphics 1 The making of charts and pictures 2 Pertaining to charts tables and their creation group member A team member who belongs to a group that is responsible for developing an application GUI See graphical user interface H hardware Physical equipment as opposed to programs procedures rules and associated documentation header The portion of a message that contains control information for the message such as one or more destination fields name of the originating station input sequence number character string indicating the type of message and priority level for the message HLLAPI High level language application programming interface A programming interface that enables a workstation application to communicate with a mainframe application HLLAPI usually operates in conj
22. The only risk can think of is working on the same edition of a class in two or more images since every method save implies a release of the current method edition into the class Therefore you might run into problems when trying to version or release the class since you may not have all the currently released methods in your image But even then a reload current on the class will do the trick You also may want to consider taking your image with you so that you are working with the same open editions The alternative is to version your code before leaving home or leaving the office and then just load it from the library when you arrive Actually there is really no need to cart the image back and forth Here is a simple process that you can follow to do nontrivial development at both the office and at home This process requires no new software or hardware It typically takes me 15 minutes or less to do the versioning and exporting and zipping required to prepare my work for travel Copyright IBM Corp 1997 243 1 Bootstrap your home system with a starter manager and a matching image You can create the manager by exporting the latest version of each configuration map or application loaded in your image 2 Going from home to work Version off the day s changes up to the application or map level and export them to a new library Zip it and put it on diskette Import the code into the office manager when you get to work
23. VisualAge for Smalltalk permits programmers to extend their applications and the Chapter 1 What Is VisualAge for Smalltalk 3 VisualAge for Smalltalk tool itself Where other tools require programmers to work within the limits of the tool VisualAge allows programmers to build new extensions to the VisualAge product that become reusable components and part of the complete Smalltalk environment VisualAge implements class based programming such that new parts become Smalltalk classes which can be part of the class hierarchy system and can be located with the Smalltalk browsers VisualAge for Smalltalk includes state of the art multimedia authoring support which allows developers to build exciting kiosk style applications VisualAge for Smalltalk also provides a report writer which provides the ability to lay out reports using the facilities of the VisualAge construction from parts paradigm Advantages of Smalltalk 4 Answer What are the key advantages of IBM Smalltalk IBM Smalltalk is a very robust Smalltalk that is based on industry standards such as POSIX for filing systems and Motif for GUI It is also based on the proposed common Smalltalk standard that was submitted to the X3J20 committee for making Smalltalk recommendations to ANSI in 1993 IBM Smalltalk contains a wide range of functions spanning more than 1100 classes in IBM Smalltalk and more than 2500 classes in VisualAge for Smalltalk IBM Smalltalk enables robust
24. Vol2 156 stored procedures Vol2 146 text Vol2 132 thread Vol2 143 transaction Vol2 14 updating 197 user feedback Vol2 155 user privilege Vol2 176 wild card Vol2 140 Windows 95 Vol2 165 date conversion Vol2 13 converting 219 defaults 212 format 212 Vol2 135 representation Vol2 135 retrieving current Vol2 135 stamp 247 DB2 2 Vol2 5 Vol2 6 Vol2 49 Vol2 124 Vol2 125 DB2 400 Vol2 135 DB2 6000 Vol2 119 Vol2 121 Vol2 124 Vol2 140 DBCS Vol2 50 Vol2 223 Vol2 255 DDCS 2 Vol2 6 Vol2 49 DDE Vol2 108 DDM Vol2 11 Vol2 14 Vol2 16 data stream Vol2 39 keyed file Vol2 26 open file Vol2 44 opening and closing file Vol2 43 performance Vol2 26 priority Vol2 41 sharing conversation Vol2 39 simultaneous access Vol2 39 ULDRECF Vol2 27 DDS generate records Vol2 31 record name Vol2 58 temporary generated Vol2 58 debug C DLL Vol2 96 distributed client Vol2 219 DLL Vol2 86 source breakpoint Vol2 86 decimal converting 210 fixed 182 point 264 default action 113 default icon 27 deferred update part 30 deleting application 249 class with instances 35 old classes 29 parts with instances 35 dependency mechanism 34 dependent attachments widget 97 dependents reinitializing 25 deselecting items 121 destroying notebook page 116 object 170 widget 95 Index 315 details view refreshing 127 details views back tabbing in container 74 device COM port 178 dialog box 134
25. Vol2 27 object space Vol2 222 verifying parameters Vol2 2 selecting multiple rows 150 semaphore Vol2 91 sender context signature serial port server 257 service program Vol2 24 session acquisition Vol2 114 class Vol2 114 data Vol2 249 Vol2 252 Vol2 253 setting focus 162 settings view changing 145 reusing 227 severity level 195 shadow Vol2 211 shape hot spot 138 SHARE EXE Vol2 24 shared folder Vol2 4 sharing data among applications files Vol2 24 menu 108 OLE objects 260 record Vol2 45 shutdown OS 2 43 Vol2 14 Vol2 16 Vol2 39 Vol2 41 196 195 178 Vol2 43 sign on dialog Vol2 17 screen Vol2 44 signature finding sender 195 single row Query Vol2 192 sizing table 149 Smalltalk advantages 4 API 172 books 165 caching compiler 192 closing DLL 55 committee 2 creating table Vol2 161 database access Vol2 154 database connection Vol2 138 description 2 distributing compiler 9 event 213 exception handling 179 fault tolerance Vol2 220 formatter 173 fractions 182 GUI architecture 87 incremental compiler 191 integer 216 method size limit Vol2 111 multiple inheritance 10 performance versus RPG Vol2 19 porting applications 10 process model Vol2 199 Server for MVS 15 source code 9 SQL INSERT Vol2 160 standardization 166 strategy 7 type converters 220 Usenet group 12 using TCP IP Vol2 66 versus C 5 versus Java 7 widget 87 smooth graphics 209 socket Vol2 66 Vol2 68 Solaris server
26. clientData nil tog2 self subpartNamed Toggle Button2 yourself tog2 primaryWidget addEventHandler KeyPressMask receiver self selector tabTo3 clientData event clientData nil tog3 self subpartNamed Toggle Button3 yourself tog3 primaryWidget addEventHandler KeyPressMask receiver self selector HtabTo4 clientData event clientData nil tog4 self subpartNamed Toggle Button4 yourself tog4 primaryWidget addEventHandler KeyPressMask receiver self selector tabTo1 clientData event clientData nil tabTo1 widget clientData clientData event event event type KeyPress ifTrue event keysym XKReturn ifTrue self subpartNamed Toggle Button1 setFocus tabTo2 widget clientData clientData event event and so on 154 VisualAge for Smalltalk Handbook Fundamentals Creating an Operation in Progress Window Answer would like to create an In Progress window that gets displayed while the application is off querying a database want to block the user interface so the users won t be able to start queuing up a lot of database queries which leads to a cache resource error have tried opening an in progress window as a full application modal but am not satisfied with the ability to hit the Esc key and exit out of the in progress window Is there another way of doing this The VisualAge for Smalltalk processing window is achi
27. creation use and maintenance of distributed applications in a heterogeneous computing environment 286 VisualAge for Smalltalk Handbook Fundamentals Distributed System Object Model DSOM An extension to SOM enabling SOM objects to reside on multiple network nodes DLL See dynamic link library domain 1 An access method its application programs communication controllers connecting lines modems and attached terminals 2 In SNA a system services control point SSCP and the physical units PUs logical units LUs links link stations and all the associated resources that the SSCP has the ability to control by means of activation requests and deactivation requests domain name The unique name that identifies an Internet site Domain names always have two or more parts separated by dots The part on the left is the most specific and the part on the right is the most general A given machine may have more than one domain name but a given domain name points to only one machine Usually all of the machines on a given network will have the same thing as the right hand portion of their domain names for example gateway mynetwork com br mail mynetwork com br www mynetwork com br and so on It is also possible for a domain name to exist but not be connected to an actual machine This is often done so that a group or business can have an Internet e mail address without having to establish a real Internet site I
28. e Programming with VisualAge for C for Windows by Marc Carrel Billiard Michael Friess and Isabelle Mauny Prentice Hall PTR 1997 ISBN 0 13 618208 9 VisualAge for Smalltalk Handbook Fundamentals VisualAge for Smalltalk Distributed by Walter Fang Sven Guyet Randy Haven Matti Vilmi and Eduardo Eckmann Prentice Hall PTR 1996 ISBN 0 13 570805 2 VisualAge for Smalltalk SOMsupport by Walter Fang Raymond Chu and Markus Weyerh user Prentice Hall PTR 1997 ISBN 0 13 570813 3 IBM Smalltalk Programming for Windows and OS 2 by Dan Shafer and Scott Herndon Prima Publishing 1995 ISBN 1 55958 749 0 Visual Modeling Technique by Daniel Tkach Walter Fang and Andrew So Addison Wesley 1996 ISBN 0 8053 2574 3 Smalltalk with Style by Edward Klimas Suzanne Skublics and David Thomas Prentice Hall PTR 1996 ISBN 0 13 165549 3 Object Technology in Application Development by Daniel Tkach and Richard Puttick Benjamin Cummings Publishing Company ISBN 0 8053 2572 7 Designing Object Oriented Software by Rebecca Wirfs Brock Brian Wilkerson and Lauren Wiener Prentice Hall PTR 1994 ISBN 0 13 629825 7 TCP IP Tutorial and Technical Overview by Eamon Murphy Steve Hayes and Matthias Enders Prentice Hall PTR 1995 ISBN 0 13 460858 5 Object Oriented Interface Design IBM Common User Access Guidelines SC34 4399 Appendix B Related Publications 273 274 VisualAge for Smalltalk Handbook Fundamentals
29. example 38 opening device 84 multiple AS 400 connections Vol2 10 inheritance 10 rows selecting 150 select list 112 windows application 89 multirow query Vol2 133 Vol2 231 multitasking Vol2 15 multithreading 28 204 mutable object 241 MWave 85 N name server changing entries Vol2 211 persistent Vol2 213 named pipe Vol2 91 naming convention 63 174 national language support See NLS navigating between columns 117 NetBIOS asynchronous function Vol2 71 dictionary Vol2 70 random errors Vol2 70 Index 325 Netware client 84 server 84 network managing traffic node Vol2 10 NFS drive 82 NLS decimals 210 double byte character set multiple languages 265 report writer default fonts search path 266 nonmodal dialog 142 nonvisual part 208 notebook advancing pages 114 bitmap on tab 115 destroying page 116 disabling tab 125 hiding page 116 migrating 117 portable 117 porting across platforms settings view 75 skipping through tab contents 115 turning pages 114 validating input 118 Novell 83 257 NSAPI 20 number converting 210 floating point 182 precision 183 rounding 182 Vol2 211 267 Vol2 229 117 114 O object changing class 231 class identification 182 copying between spaces creating at compile time creation 174 destroying 170 dumper 39 247 Vol2 229 Vol2 198 167 326 VisualAge for Smalltalk Handbook Fundamentals object continued finalization 171 identity 226 240 im
30. host 3270 emulator Vol2 79 passing data Vol2 36 presentation space server program Vol2 36 services Vol2 12 transaction interface variable Vol2 162 ODBC driver hot spot border 138 coordinates image 140 reshaping hover help behavior 198 push buttons widgets 157 HP printer Vol2 233 HTML form Vol2 249 form data Vol2 250 image Vol2 250 links Vol2 252 literal text Vol2 252 session data Vol2 252 Vol2 80 Vol2 111 Vol2 114 Vol2 113 Vol2 42 138 138 32 ICAPI icon adding dynamically to container adding to list 129 as cursor 103 DLL 48 gadgets 107 in container column missing 50 missing after packaging 50 moving 152 on menu 108 push button 157 removing from container VisualAge 70 20 125 125 128 320 VisualAge for Smalltalk Handbook Vol2 79 Vol2 80 126 Vol2 42 Vol2 127 Vol2 140 Vol2 146 Fundamentals identical users 256 identity 221 226 240 ILE Vol2 24 image backup copy 24 base 23 calling from OS 2 Vol2 91 CAT files 264 cleaning 23 cleared cache click sensitive closing windows component 15 component packaging 75 concurrently running 83 connecting to cloned library 248 copyright 200 creating 23 disconnecting remote exiting 199 finding remote object space pointers Vol2 219 formats 140 growing after packaging 26 hot spot 138 live updating 33 loading different memory allocation merging applications missing class 52 owner 251 package size packaged
31. see the visualag install visualag api file for a list of redistributable classes and methods this is partly because those workspaces have menu options for evaluating code using the compiler which is definitely not packageable If you are looking to simply reproduce an editor window just drop a multiline edit part in a window Image Reduction 48 Answer How do strip down my development image The VisualAge for Smalltalk packager is functionally equivalent to the third party and OEM strippers that are available for other Smalltalks They all analyze your image and remove unneeded classes and methods The major difference is that some of the better third party strippers can dynamically analyze the running system where the VisualAge packager does only a VisualAge for Smalltalk Handbook Fundamentals static analysis Even so the packager does a pretty good job of getting the image size down Ensuring that Needed Classes are Packaged Answer How can make sure that all classes and methods need for an application are packaged given that the classes are spread over various applications Would it be sufficient to include two private methods packagerIncludeSelectors and packagerIncludeClassNames The packager excludes all applications that are not part of the prerequisite list even if you implement one of the methods packager ncludeSelectors packagerIncludeClassNames By using one of these methods you are tell
32. small 241 intercepting key stroke Vol2 80 interface repository Vol2 243 Internet ITSO xvii interrupting infinite loop 28 interval reverse 190 to method 189 invisible part 45 INZPFM Vol2 26 IPMD Vol2 86 IRDUMP Vol2 243 ISAPI 20 iterating over widgets 94 iterator field break Vol2 226 header color Vol2 231 ITSO feedback xviii FTP server xviii Internet xvii redbooks home page xvii World Wide Web xvii J Java beans 22 job asynchronous Vol2 12 DDM requests Vol2 43 description Vol2 12 library list Vol2 57 log Vol2 53 queue Vol2 59 sharing data Vol2 43 unspecified key Vol2 63 join outer Vol2 146 JPEG support 20 Index 321 K key accelerator 157 alteration Vol2 112 compound Vol2 28 Ctrl 159 dictionary 234 function 163 intercepting stroke Vol2 80 lookup table 234 partial Vol2 29 pressed event 230 release 134 simple Vol2 29 specifying Vol2 29 unique Vol2 46 unspecified Vol2 63 keyboard event handler 230 foreign characters 265 handling 159 input 141 L label changing color 120 multiline text 130 LAN LAN Server 400 Vol2 7 OS 2 LAN Server Vol2 7 last selected item 112 launching application 203 legacy code 9 library access 84 available classes 257 cloned 248 closing DLL Vol2 98 consistency 253 corruption 83 deleting application 249 ENVY Manager 257 growth rate 254 importing application 245 list Vol2 57 322 VisualAge for Smalltalk Handbook Fundamentals library co
33. 0000 173 Contents IX x Testing Instances and Classes 0 173 Garbage Collection Rate 2 2 2 0 0 200000048 174 Inherited Messages 00022 e 175 File System er aiea tai e a eee wee ee SPARS 176 File EXISTENCE 4254 3214 44 lead by a Be AA e de 177 Accessing COM Ports 0 2 0000 pe ee 178 Gatching Errors ova Steet ee Ae ge ee St es 179 File Systeim Errors und ea y She ee ee BSE ek A 180 Catching All Errors s sean eat ures snip o ok Gaa PG 181 Exception Handling Code 00 00 0020 0005 182 Fixed Decimal Class 00 00 0002 2p ee 182 Object Class Identification 2 o 182 Floating Point Numbers e 182 Reversing Collections 0 2 00 00020 Dee 186 SubStringS di it BA heh wo eee ta a 186 Implementation of become a 02000 2 ee 187 ll y eae A eh ose sy kl he ee te ao i ate 189 Interval gt gt reverse Method 000000022 190 Updating Widgets 2 0 0 0 a ee 191 Incremental Compiler 0 2 0 2 0 020000002 191 Caching Compiler 2 0 2 0 00002 ee ee 192 Creation of Blocks at Run time 00200 192 Pool DictiOnares cava 2204 Stade dae e eee SE aE Rot Sale 193 Text Color Changes 0 000 2p 193 Sorting SortedCollections 2 2 2 0 0 20 2 0048 194 Compiler Severity Level 00 0000 0000200 195 Finding the Sender Signat
34. 10 do block For convenience the to and to by messages of Number answer intervals so this can be written as Smalltalk 1 to 10 do block And for convenience the to do and the to by do messages of Number make things even easier Smalltalk 1 to 10 do block Interval gt gt reverse Method Question The comment explaining what reverse does says Answer a object conforming to the same protocols as the receiver but with its elements arranged in reverse order can t make head or tail of this Why not say simply Answer an Interval in reverse order Inspect the following code Smalltalk 0 to 5 reverse The elements of the result are just as you expected However the class of the result may not be what you expected notice it s an Array not an Interval 190 VisualAge for Smalltalk Handbook Fundamentals Updating Widgets Answer We have some code that sends messages to a visual part which is then supposed to display some status information in a text window The code works fine except that the status messages are showing up asynchonously that is none show up at all until they all show up at once in a big flood am guessing that what is happening is that the VisualAge part is getting some events queued up but that these events aren t handled until the user interface process gets control again Is there s
35. 102 object table 187 pointer continued passing Vol2 101 recaching 243 248 remote object Vol2 197 retaining address Vol2 89 weak 170 pool dictionary Abt3270HIlapiConstants Vol2 80 AbtMQConstants Vol2 74 CfsConstants 176 corrupted Vol2 3 defining 198 establishing 197 excluded keys 51 exporting 254 NisGlobals Vol2 136 packaging 51 replacing associations 197 repopulating Vol2 3 resolving references 193 SystemExceptions 180 using 197 pop up menu extending 57 port COM 178 number Vol2 221 portability CUA 88 Windows 95 88 portable notebook 117 porting drag and drop 129 notebook across platforms 117 Smalltalk applications 10 positioning window at cursor 90 POSIX 2 PostScript Vol2 232 precision 183 prerequisite 52 81 preventing image growth 25 primary part 69 primitive error code 73 Vol2 97 failed Vol2 124 object 217 Index 329 printer save settings printf 173 printing conditional Vol2 227 printing form with visual part proc dialog APPC Vol2 71 CICS Vol2 72 code page Vol2 73 transaction abend Vol2 72 process aborting stack 199 background 201 forking 197 pausing 197 synchronization processor 196 profiler 216 Vol2 211 program asynchronous calling Vol2 40 CICS Vol2 72 COBOL Vol2 71 listener Vol2 73 partner Vol2 34 signaling end Vol2 84 starter Vol2 59 Vol2 84 synchronous calling Vol2 40 working directory Vol2 84 Vol2 229 152 209 progress indicator 137 Vol2 155 messa
36. 153 SOM object Vol2 240 table list 149 validation 152 with instances deleting 35 partial key Vol2 29 passing data Vol2 36 parameters 34 password protection 244 pausing process 197 PC Support communication error Vol2 2 Rumba Vol2 10 status Vol2 17 TCP IP Vol2 51 user ID Vol2 17 PCL print stream Vol2 233 peer to peer communication Vol2 207 performance access set Vol2 127 activator Vol2 199 class naming 226 concatenation 237 performance continued copying object Vol2 221 CPI C Vol2 114 DDM Vol2 26 degrading 24 dictionary 234 dynamic session acquisition Vol2 114 file access part Vol2 60 hiding visual objects 158 image size 24 logical view Vol2 26 lookup table 234 Novell Client32 258 object space Vol2 216 ODBC Vol2 48 Vol2 60 Vol2 172 opening and closing file Vol2 43 opening widgets 158 Oracle Vol2 172 readAll Vol2 14 record cache Vol2 19 report printing Vol2 233 Smalltalk versus RPG Vol2 19 SQL Vol2 48 stream 237 trace logging 54 type converters 220 unloading application 56 Windows 95 83 persistence 217 Vol2 213 Personal Communications Vol2 37 phantom instance variables Vol2 113 physical file Vol2 14 platform drag and drop 20 129 function Vol2 95 function available Vol2 96 maximize window 91 porting notebook 117 screen resolution 95 Windows 16 bit Vol2 62 PlatformFunction Vol2 101 PlatformWidgetsConstants 41 pointer dead Vol2 204 manipulation Vol2 82 motion mask
37. 1670 Finnish 45 4810 1120 Spanish 45 4810 1220 French 45 4810 1170 Swedish Mail Orders send orders to IBM Publications IBM Publications IBM Direct Services Publications Customer Support 144 4th Avenue S W Sortemosevej 21 P O Box 29570 Calgary Alberta T2P 3N5 DK 3450 Aller d Raleigh NC 27626 0570 Canada Denmark USA Fax send orders to United States toll free 1 800 445 9269 Canada 1 403 267 4455 Outside North America 45 48 14 2207 long distance charge 1 800 IBM 4FAX United States or 1 001 408 256 5422 Outside USA ask for Index 4421 Abstracts of new redbooks Index 4422 IBM redbooks Index 4420 Redbooks for last six months Direct Services send note to softwareshop vnet ibm com On the World Wide Web Redbooks Home Page http www redbooks ibm com IBM Direct Publications Catalog http www elink ibmlink ibm com pbl pbl Internet Listserver With an Internet e mail address anyone can subscribe to an IBM Announcement Listserver To initiate the service send an e mail note to announce webster ibmlink ibm com with the keyword subscribe in the body of the note leave the subject line blank VisualAge for Smalltalk Handbook Fundamentals IBM Redbook Order Form Please send me the following Title Order Number Quantity First name Last name Company Address City Postal code Country Telephone number Telefax number VAT number e Invoice to custome
38. 2 To arrange such things as characters fields and lines FQDN Fully Qualified Domain Name The official name assigned to a computer Organizations register names such as bm com or utulsa edu They then assign unique names to their computers such as watson5 ibm com or tornado cs utulsa edu framework A library of classes intended for reuse that fall within a particular domain for example a communications framework or a graphics framework free form surface In VisualAge the large open area of the Composition Editor window The free form surface holds the visual parts contained by the views a user builds and representations of the nonvisual parts that an application includes FTP File Transfer Protocol The basic Internet function that enables files to be transferred between computers You can use it to download files from a remote host computer as well as to upload files from your computer to a remote host computer See Anonymous FTP function 1 A specific purpose of an entity or its characteristic action 2 In data communications a machine action such as carriage return or line feed G garbage collection A Smalltalk process for periodically identifying unreferenced objects and deallocating their memory gateway A device and its associated software that interconnect networks or systems of different architectures The connection is usually made above the reference model network layer GET
39. 3 Graphical User Interface 97 Widget A Widget B The nonobvious restriction with attachments is that in order for Widget B to successfully attach to Widget A Widget A s edges must be fully resolved That is they can t be directly or indirectly by additional widgets based on any of the edges of Widget B Always on Top Window Answer We have built a tool bar for our application We would like the tool bar window to always stay on top Is there a way in VisualAge for Smalltalk to set a window to always stay on top know there is a windows application programming interface API that will keep a window on top but do not know how to get to if from VisualAge An easy way to do this is to use CwOverrideShell rather than CwTopLevelShell as the shell class for the window This will cause it to float on top of all other windows If you want the tool bar to float on top of a specific window then make the tool bar a child of the other window by setting its parent to be the other window Either of the above methods requires digging into IBM Smalltalk a bit Changing the Mouse Pointer 98 When the mouse pointer enters into the scope of an editable field the pointer changes from the arrow to the I beam Is it possible to accomplish a similar behavior while crossing over some arbitrary other control like a form or button VisualAge for Smalltalk Handbook Fundamentals Answer To change the shape of the pointer whe
40. 51 user ID Vol2 17 Windows Vol2 59 cloned library 248 VisualAge for Smalltalk Handbook Fundamentals close option disabling 97 closing widget 96 window 95 CM 2 Vol2 50 AS 400 access Vol2 4 configured AS 400 systems Vol2 2 conversation security Vol2 27 optimized client Vol2 21 packaging AS 400 application profile list Vol2 28 setup Vol2 18 Vol2 27 user ID Vol2 17 CM 400 Vol2 7 Vol2 50 COBOL 9 55 Vol2 83 Vol2 98 Vol2 101 COBOL accessing through CICS Vol2 71 code page AS 400 Vol2 12 CICS Vol2 73 connection specification conversion 75 263 266 missing translation table 44 MPR file 263 support 263 collection do 218 heap sorted 219 interval 189 reversing 186 sorted 194 218 color bitmap resolution 131 changing 193 iterator header label 120 wallpaper 138 column adding to table 146 hiding 145 navigating between 117 resizing 123 COM port accessing 178 combo box adding items 110 behavior 114 default action 113 selected item Vol2 62 Vol2 21 Vol2 109 Vol2 231 combo box continued synchronizing 109 command bind syntax Vol2 117 CRTLF Vol2 31 DSPNETA Vol2 10 OVRDBF Vol2 43 OVRSCOPE Vol2 43 remote Vol2 43 Vol2 53 STRCMTCTL Vol2 1 command line arguments 200 commitment boundary Vol2 1 control Vol2 1 Vol2 59 Vol2 75 Vol2 78 Vol2 145 common file system API 176 common widgets reinitializing 25 communication AS 400 Vol2 2 saving image Vol2 35 static session acquisition
41. 95 override database Vol2 43 P package including classes in 46 packaged image 46 packaging 54 application Vol2 57 application prerequisites 52 Vol2 22 AS 400 Vol2 22 AS 400 application Vol2 8 Vol2 21 AS 400 sign on screen Vol2 44 changing database name Vol2 174 class modifications 49 database samples Vol2 194 distributed Vol2 217 distributed application Vol2 212 distributed tracing Vol2 195 for other platform 48 garbage collecting 26 image growing 26 image size Vol2 22 instruction 76 launch code 203 method exclusion Vol2 200 missing icons 50 missing method 53 packaged image browser 47 pool dictionaries 51 remote object pointer Vol2 204 removing methods 46 report application Vol2 230 required CAT and MPR files 76 required CAT files 264 required classes 49 required ICs 75 retaining classes Vol2 218 scan messages 50 target environment 252 Web application Vol2 251 without SWP files Vol2 3 workspace 48 packaging AIX 47 328 VisualAge for Smalltalk Handbook Fundamentals packaging in target environment 47 padding strings 223 palette 131 139 parameter passing 34 Vol2 98 parameter marker Vol2 42 parsing COBOL copy book Vol2 101 macro file Vol2 113 string 219 part AS 400 file access Vol2 4 changing settings view 145 composite Vol2 251 DBCS name Vol2 255 destroying 95 distributing Vol2 210 error when saving 69 invisible 45 labels 160 object list Vol2 59 primary 69 printing form 152 reusable table 149
42. Andreas Huber Greg Hutchinson Mike Jacobs Charif Jaouhar Chuck Jaynes Christopher Joak Greg Johnson Tom Johnson Jane Jones Gary Karasiuk Gijsbert Karens Dan Kehn John Kellington Dave Kennedy Brian Kent Kelly Keplinger Alan Knight George Kober Martin Kunz Bruce Lambert Micky Lim Michael Linderman Daniel Lipp Grace Liu Bill Lockard Tom Logan Mark Lorenz Pablo Lorenzo Sabina Luzzatti Stewart MacLean Bill Mathews Cynthia McCrickard David McGee John McIntosh Ted McKnight Gerald Meazell Eric Meredith Jim Mickelson Gonzalo Mourino Pat Mueller Gen Nagatsuka Martin Nally Binh Nguyen Jimmy Nguyen Achim Nogli Ami Noyman Patrick O Donnell John O Keefe Dan Ohlhaut Omar Padilla Jim Pendergast Rosa Peral Ralf Pfiszter Enrico Piccinin Oliver Picot Guenter Pindhofer Rene Plourde Greg Plummer Bob Poulton Steve Reeves Brian Remedios James Rendell Scott Rich Cameron Roy Jouko Ruuskanen Jari Saari Craig Setera Dan Shaver Ed Shirk Allen Smith Christine Smith Craig Smith David Smith Larry Smith Daniel Stainhauser Jim Stewart Jeff Stratford Jean Talbott Steve Tang John Tobin Mark Tompkin Mike Toohey Rick Trotter David Twyerould Timo Ullrich Harold Wadler Jim Wason Christopher Webster Tony Weddle Ronny Weisz David Whiteman Mark Wilkes Joe Winchester Rory Woodward Cindy Wotus Glorious Wright Alfred Wu Barry Young Ric Zapanta Sherwood Zern and Slavik Zorin for their numerous co
43. Answer ais i object This will include a return character at the end of each string from the multiline editor Action on PFkey Pressed Question would like to close a window when the PF12 key is pressed The problem have is how to see if PF12 gets pressed This is not quite as trivial as it seems but it can be done 1 Every visual part you attach to your window has a corresponding CwWidget attached to it It can be accessed via self subpartNamed myTextf widget lt is accessible once the window is created for example in scripts hooked to aboutToOpenWidget 2 Attach a keyboard message handler to each and every such widget that is capable of getting input focus something like this Smalltalk self subpartNamed myText widget addEventhandler KeyReleaseMask receiver self selector keyRelease clientData event clientData nil 3 Code the actual event handler corresponding to the selector Create a method with signature keyRelease clientData event 4 Every time a key is released this method will be called The event is the place to look for specific key information just printString it to the Transcript it will tell you most everything about the key released Whenever you think it is appropriate to close the window just do it Chapter 3 Graphical User Interface 163 164 VisualAge for Smalltalk Handbook Fundamentals Chapter 4 IBM Smalltalk Programming Language This chapter cov
44. Click OK The versions of the applications you selected will be loaded into your image Save the image Chapter 5 ENVY 245 Moving Components Between Libraries Tip You can move components between two libraries directly without exporting or importing them For example to move your applications from a Version 3 0 Manager to a Version 3 0a Manager without exporting or importing do the following From within your Version 3 0a image that is connected to the Version 3 0a manager choose Import and specify the Version 3 0 old manager as the file to import from It will then bring up the list of all applications in the manager You can choose all that you need to import over Remember Your Manager is essentially a normal DAT file Archival Code Answer I m using VisualAge for Smalltalk Professional use only import export and not filein fileout Do still need to generate archival code No you don t need the archival code The primary purpose of archival code is for sharing code between standalone images With the Professional product import export is much preferred So with VisualAge for Smalltalk Professional there may be only two cases when you might want archival code e If you want to move code to a Standard image If you are creating several copies of a part and want to modify the filed out version of it to file it in Identifying the Released Version 246 Answer How do see which versi
45. Contents Xilli XIV VisualAge for Smalltalk Handbook Fundamentals Preface This book addresses many common questions in the VisualAge for Smalltalk development arena It covers various aspects of VisualAge and IBM Smalltalk through answers to frequently asked questions hints and tips from users and developers and online bulletin boards inside and outside of IBM This redbook will help VisualAge for Smalltalk developers find answers to their everyday questions The book provides usage guidelines for areas such as change management performance database access and transaction processing to help developers avoid common programming pitfalls The VisualAge for Smalltalk Handbook has two volumes e Volume 1 Fundamentals Volume 1 covers general programming questions on such topics as image maintenance graphical user interfaces naming conventions and the IBM Smalltalk language e Volume 2 Features Volume 2 focuses on VisualAge for Smalltalk features such as AS 400 Connection Communications and Transactions Distributed Reports and Web Connection This book is written for VisualAge for Smalltalk programmers project leaders and developers Understanding many of the questions and answers in this book requires substantial knowledge of the VisualAge for Smalltalk product and the Smalltalk language This book does not discuss questions related to methodologies analysis and design For a discussion of object oriented anal
46. Copyright IBM Corp VisualAge Concepts and Features GG24 3946 VisualAge and Transaction Processing in a Client Server Environment GG24 4487 AS 400 Application Development with VisualAge for Smalltalk SG24 2535 World Wide Web Server Development with VisualAge for Smalltalk SG24 4734 VisualAge Building GUIs for Existing Applications GG24 4244 VisualAge for Smalltalk Distributed SG24 4521 VisualAge for Smalltalk and SOMobjects SG24 4390 OO Programming with Client Access for OS 400 and ODBC using VisualAge for Smalltalk SG24 4718 Application Development with VisualAge for Smalltalk and MQSeries SG24 2117 Object Oriented Application Development with VisualAge for C for OS 2 SG24 2593 Programming with VisualAge for C for Windows SG24 4782 IBM VisualAge for Cobol for OS 2 Workframe User Guide SG24 4604 IBM VisualAge for Cobol for OS 2 Primer SG24 4605 IBM VisualAge for Cobol for OS 2 Object Oriented Programming SG24 4606 Visual Modeling Technique Object Technology using Visual Programming SG24 4227 1997 271 Redbooks on CD ROMs Redbooks are also available on CD ROMs Order a subscription and receive updates 2 4 times a year at significant savings CD ROM Title Subscription Collection Kit Number Number System 390 Redbooks Collection SBOF 7201 SK2T 2177 Networking and Systems Management Redbooks Collection SBOF 7370 SK2T 6022 Transaction Processing and Data Management Redbook SBOF 7240 SK2T 8038
47. Guide for details Dragging Versus Pop Up Answer What is the difference between obtaining a pop up menu and dragging Drag does not start unless the mouse is moved a threshold amount If we are not in drag mode the pop up is displayed This is a general algorithm it varies slightly depending on the platform you are running on Icons on a Menu Bar 108 Answer tried adding an icon as a menu bar item and a menu pull down item To do that created a menu as usual then selected Open Settings from the Menu Choice pop up menu then clicked on Label Type Graphic Graphic Type Icon Module name abticons ID 1 That gave me a file cabinet icon on the menu but the icon was displayed as a bitmap that is the background was white not transparent The comment in the AbtLabelView gt gt calcGraphicLabelType says For OS 2 and Windows only bitmaps not icons are allowed as menu items so if the parent will be a menu then force the graphic to be a pixmap Is there a remedy I ve not seen a menu bar at the bottom of the frame but that is not native widget behavior The word processor must be implementing this or perhaps to use PM terminology overriding WM_FORMATFRAME to move it to a new location You may want to investigate using an AbtRowColumnView for building your tool bar It can be attached to the bottom the top or wherever on your window It is a special part that automatically attaches buttons to each ot
48. ICAPI Netscape s NSAPI and Microsoft s ISAPI on any platform that is supported by both the Web server product and VisualAge for Smalltalk The CGI interface continues to be supported Usability Drag and drop or direct manipulation of objects in a GUI is one of the most intuitive and efficient methods for interacting with a software application Version 4 0 adds platform drag and drop which allows you to drag objects between applications written in Smalltalk and any other drag and drop enabled application or any desktop object on any platform You can now let VisualAge for Smalltalk Handbook Fundamentals the users of your VisualAge for Smalltalk applications avail themselves of the improved usability and efficiency of drag and drop Enabling drag and drop for visual parts is as simple as changing a property setting on the part Speaking of property changes the most obvious and pervasive usability improvement in Version 4 0 is the new property view for parts This view appears whenever you want to display or change the properties or settings for a part typically by double clicking on the part Gone is the tedium of flipping notebook pages to find and change various properties and their values Instead you use a scrollable two column table which displays the property name on the left and its value on the right Your productivity is improved greatly when changing several properties for a part as the table is easy to use Optiona
49. If your connectivity is through Microsoft Windows for Workgroups 3 11 MSDLC protocol and Client Access 400 V3R1 router be aware that the CA 400 DOS Extended client is not supported for use with either MSDLC or VisualAge AS 400 Connection see AS 400 Connection User s Guide SC34 4544 0 under Chap 1 Getting Started section on Prerequisites for Windows In this case you must use the Client Access 400 for Windows 3 1 client Chapter 2 General Information 61 AbtRecord Question How do use AbtRecords There are some references to AbtRecord in the online Communications Transactions Guide and Reference One way to create an AbtRecord instance is by sending the message newRecord to an AbtCompoundType Here is an example found Smalltalk ctype rec ctype AbtCompoundType new addField AbtCOBOLDisplayField new name string1 length 8 addField AbtCOBOLDisplayField new name string2 length 8 yourself rec ctype newRecord rec at string1 put abcde rec at string2 put ddddd Transcript cr show rec at string1 cr show rec at string2 Indexed Message Editor Tip find that whenever made changes in the Indexed Message Editor need to 1 Save the changes 2 Execute application abtGenerateExternalizedStringslfNecessary 3 Execute AbtNLSCoordinator forceRelocalizationOfSeparatedConstants After do this
50. SNA network address and transformed to or from an SNA network address by the boundary function in a subarea node local area network LAN 1 A network in which devices are connected to one another for communication and can be connected to a larger network See also token ring 2 A network in which communications are limited to a moderately sized geographic area such as a single office building warehouse or campus and do not generally extend across public rights of way Contrast with wide area network local node In the subsystem the node from which one views the rest of the OSI network the node for which resources are defined Contrast with remote node logical file A description of how data is to be presented to or received from a program This type of database file contains no data but it defines record formats for one or more physical files The record formats allow a developer to present different views of the data in a physical file logical unit LU In SNA a port through which a user gains access to the services of a network A logical unit can support two types of sessions with the host and with other LUs See logical unit 6 2 logical unit LU 6 2 A type of logical unit that supports general communication between programs in a distributed processing environment LU 6 2 is characterized by 1 a peer relationship between session partners 2 efficient utilization of a session for multiple transacti
51. Smalltalk 11 CompuServe Question Which forums are available on CompuServe The CompuServe forums for VisualAge for Smalltalk are e Free for all e Install Begin e Communications Languages e Database e AS 400 Feature e How to e Everything Else e Bug Reports e Third Party e IBM Smalltalk e Classifieds Usenet Question Is there a Usenet group dedicated to Smalltalk Yes COMP LANG SMALLTALK Resource Catalog 12 Question How can get the resource catalog about vendors of components for VisualAge for Smalltalk The document number of the Resource Catalog is G325 0813 If you work for IBM you can order it through Puborder The catalog is also accessible from the VisualAge home page on the World Wide Web http www software ibm com software ad vastub html Be sure you are getting the latest catalog if you order a hard copy VisualAge for Smalltalk Handbook Fundamentals Learning Courses Question Where can find out about a suggested sequence of courses for application programming with VisualAge and IBM Smalltalk The Object Technology University OTU offers a curriculum for VisualAge for Smalltalk For more information visit their Web site at http www training bm com ibmedu roadmaps client ot New Features in Version 3 Question What are the new features in VisualAge for Smalltalk Version 3 The functions of Version 2 plus Development and run time support for AIX Version 4 1 3
52. Smalltalk development environment from OTI having features that no other Smalltalk development environment has Originally ENVY was an environment to be based on top of other basic Smalltalk implementations But now in IBM Smalltalk you have a full from scratch integration between the language and the environment Stability and Maturity 2 Answer How stable and mature is VisualAge for Smalltalk VisualAge for Smalltalk was in development for several years before it became generally available in the first quarter of 1994 According to Eric Ostrom a consultant for IS International VisualAge for Smalltalk is the most solid release 1 development tool have ever used Each release is faster and offers more features Version 3 0 with distributed Smalltalk is outstanding Standards conforming IBM Smalltalk and therefore VisualAge for Smalltalk is based on the proposed common base Smalltalk specification submitted to the X3J20 committee for making Smalltalk VisualAge for Smalltalk Handbook Fundamentals Openness Answer recommendations to ANSI Both the chairman and secretary of the ANSI Smalltalk committee work for IBM in Smalltalk development In addition IBM Smalltalk adheres to industry standards of OSF Motif X Windows POSIX and IBM s CORBA implementation SOM In what respect is VisualAge for Smalltalk open It is portable among platforms Windows OS 2 AIX Sun and HP VisualAge for Smalltalk supp
53. Smalltalk support multiple inheritance No Multiple inheritance is a property that has been confused as a characteristic of the OO paradigm It is not It is only mildy useful in certain situations invariably it causes objects to carry more attributes than necessary Porting Smalltalk Applications Questioni How do port a Smalltalk application to VisualAge The recommended approach is to import through a DAT file or file in through an ST file the model code The GUI code should be rebuilt in VisualAge because the effort to port may exceed the effort to rebuild 10 VisualAge for Smalltalk Handbook Fundamentals Sources of Support Question Once purchased VisualAge for Smalltalk what kind of support can expect A varietyof support is available including TalkLink Sixty days of free IBM direct telephone support TalkLink forums CompuServe forums Web for DAP members Technical support consulting education training and more from third parties Question Which forums are available on TalkLink Talklink s public forums for VisualAge for Smalltalk are IBMPARTS IBM Parts for Visualage for Smalltalk VADIST Distributed feature VAIMS CICS IMS feature VAINSTAL Install questions VACOMLNG Communications and Language features VA400 AS 400 Connection feature VAOTHER Other topics not covered VAHOWTO How to questions VADB Database questions VABUGS Bug reports Chapter 1 What Is VisualAge for
54. The default settings provided on installation have been tested in most cases there is a trade off between data integrity and performance for example True Commit set to off Although other settings have not been tested changing any of the settings in the Performance Cache parameter group to less optimistic values should not present any problems Chapter 2 General Information 83 When using this configuration set ENVY Manager s release lock mode parameter to true Windows NT Client Windows NT clients must only use the Microsoft Client Services for Netware CSNW that is provided with Windows NT 3 51 The Novell Netware Client for Windows NT should not be used as it has not been tested with VisualAge for Smalltalk When using this configuration set ENVY Manager s release lock mode parameter to true OS 2 Warp 3 Client From an OS 2 Warp 3 client use Novell s OS 2 2 11 requester for library access OS 2 Warp 4 Client Direct access to Novell Netware servers from Warp 4 is not currently supported OS 2 Warp 4 customers should use EMSRV for library access Opening Multimedia Devices Tip Open only one multimedia device for example Digital Video Player at a time Make sure you close one device before opening another otherwise unexpected results may occur This is an OS 2 Warp limitation Using Digital Video Player on OS 2 Tip To use the Digital Video Player move the MMOS2 directory to the beginning o
55. Vol2 114 Windows 3 1 Vol2 62 Communications Manager 2 See CM 2 comparing floating point 183 floating point 239 compatibility 10 compile time creating object 167 compiler caching 192 incremental 191 literal strings 227 optimization 221 severity level 195 warning 195 component moving between libraries 246 composition editor window location 90 compound key Vol2 28 CompuServe xix 12 Vol2 9 concatenation 237 configuration 5250PLU Vol2 2 VisualAge 213 configuration map deleting application 249 distributed load Vol2 201 configuration map continued distribution matrix Vol2 206 exporting 252 254 loaded features 253 version control 257 configured subsystems 199 connecting to AS 400 Vol2 2 to remote host Vol2 2 connection menu customizing 33 connection releasing 95 container adding icons dynamically 126 adding records 120 back tabbing in details views 74 check box 119 column list box 119 context menu 127 deselecting items 121 details tree 121 details tree children 124 details view 124 hiding column 125 hiding heading 124 icon column 125 nonexistent attribute 129 object attribute 128 OLE client 260 refreshing 128 refreshing details view 127 remove items 125 removing icon 128 resizing columns 123 scroll bar 124 selecting multiple rows 150 selection 117 sharing menu 108 valid objects 117 context menu 74 continuing background process 201 control widget buffering 30 controller class 65 conversation securi
56. WeakKey collections or WeakValue collections have slightly different behaviors that the class names are trying to describe A weak collection can be used as a cache to hold cached objects The cache itself can be assigned to a global variable a class variable and so VisualAge for Smalltalk Handbook Fundamentals on Since the cache is a weak collection references to the cache objects are not considered permanent references Normally if want to use the same object A in several windows would save that value in a global variable or put that object A in some global collection It is especially true if those several windows don t really have any logical connection to each other Since the object A is referenced by a global variable it is not a candidate for garbage collection However if the global cache collection is a weak collection every element of that collection is a candidate for garbage collection if that particular element is no longer referenced by any object that is live in terms of garbage collection Object Finalization Answer heard that now finalization is a hot topic What is it actually Does IBM Smalltalk support it If yes in what way Finalization is roughly like destructors in C Normally you don t need to take any special actions to free objects When an object is no longer needed there are no more references to it the Smalltalk garbage collector removes it from the object memory Ther
57. Wrapper holds self new SomeClass gt gt x X SomeClass gt gt x aValue x aValue The Wrapper class would look like this Smalltalk Wrapper class gt gt holds anObject self new holds anObject Wrapper gt gt holds anObject wrappedObject anObject Wrapper gt gt x wrappedObject aboutToExecute x wrappedObject x Wrapper gt gt x aValue wrappedObject aboutToExecute x wrappedObject x aValue Then Smalltalk ab a SomeClass new b a b x 234 causes the object in a to be sent the aboutToExecute message passing x Chapter 4 IBM Smalltalk Programming Language 207 Smalltalk Class or AbtAppBldrPart Answer What is the difference in using a Smalltalk class as opposed to a nonvisual part when creating business classes and what are the implications One of the main differences between a Smalltalk class and a VisualAge nonvisual part is that you have a Composition Editor with the latter The Composition Editor allows you to do visual programming within the nonvisual part This means that you can drop parts on the Composition Editor and make connections between them Obviously you wouldn t put visual parts for example a text part on the Composition Editor of a nonvisual part but you could place any nonvisual part or Smalltalk class on the Composition Editor and make connections between anything defined in the public interface for those parts When you want to c
58. a job that are used to identify the job or describe its requirements to an operating system journal A system object that identifies the objects being journaled the current journal receiver and all journal receivers on the system for the journal The system recognized identifier for the object type is JRN journaling The process of recording in a journal the changes made to a physical file member Journaling allows the programmer to reconstruct a physical member by applying or removing the changes in the journal to a saved version of the physical file member journal receiver A system object that contains journal entries added when changes are made to an object for example when an update is made to a file being journaled The system recognized identifier for the object type is JRNRCV JPEG Joint Photographic Experts Group The name of the committee that designed the photographic image compression standard JPEG is optimized for compressing full color or gray scale photographic type digital images It doesn t work well on drawn images such as line drawings and it does not handle black and white images or video images K kbps kilobits per second A speed rating for computer modems that measures in units of 1024 bits the maximum number of bits the device can transfer in one second under ideal conditions keyword 1 One of the predefined words of an artificial language 2 One of the significant and inform
59. a class is that edition s class developer Contrast with class owner class extension An extension to the functionality of a class defined by another application The extension consists of one or more methods that define the added functionality or behavior These methods cannot modify the existing behavior of the defined class they can only add behavior specific to the application that contains the extended class class hierarchy A tree structure that defines the relationships among classes A class has subclasses down the hierarchy from itself and superclasses up the hierarchy from itself The methods and variables of a class are inherited by its subclasses class instance variable Private data that belongs to a class The defining class and each subclass maintain their own copy of the data Only the class methods of the class can directly reference the data Changing the data in one class does not change it for the other classes in the hierarchy Contrast with class variable class method A method that provides behavior for a class Class methods are usually used to define ways to create instances of the class Contrast with instance method class owner Team member responsible for the integrity of that class in an application edition The class owner is responsible for releasing class versions Contrast with class developer class variable Data that is shared by the defining class and its subclasses The instance method
60. all my messages are immediately available never have to unload or reload the application 62 VisualAge for Smalltalk Handbook Fundamentals Corrupted MRI File Answer The messages in my MRI user message file appear corrupted or have bad data What can be wrong The MRI file in VisualAge for Smalltalk Version 1 0 has a limit of 64 KB so messages above this limit may appear corrupted To get past the limit in application AbtNLSSubApp change class AbtMRIGroupHeader method offsetSize as follows Smalltalk offsetSize Public answer size of file offset used in header offsetSize isNil ifTrue offsetSize 4 ifFalse offsetSize The only change in this method is to change the number 2 to 4 For VisualAge for Smalltalk Version 2 0 the changes have already been made In the method above the offsetSize now defaults to 4 instead of having to change it to 2 So corruption should no longer be a problem in Version 2 0 Class Naming Convention Answer What naming convention should use Our naming convention complements existing literature on the subject to facilitate code reuse and to provide a layered architecture for the development environment A naming convention in your development environment greatly helps reusing existing classes because it allows searching by class name based on a filter e VisualAge for Smalltalk Programmer s Guide to Building Parts for Fun and Profit IBM
61. and types of the data it contains RecordStructure classes Classes that provide a flexible open architecture for converting Smalltalk objects to and from data types of other languages release A system operation on a component that changes its containing component s configuration Releasing a component adds its released edition or version to the configuration for its containing component When a containing component is loaded into an image the released editions or versions of the components it contains are also loaded remote Concerning the peripheral parts of a network not centrally linked to the host processor and generally using telecommunication lines with public right of way remote node Any node other than the local node Contrast with local node repository 1 An organized shared body of information that can support business and data processing activities 2 In VisualAge or IBM Smalltalk the multiuser library that stores components such as applications classes and methods created by application developers It stores source code object code and persistent objects request A service primitive issued by a service user to call a function supported by the service provider reset button A type of push button that can appear on a form A reset button restores all input fields to their default states resource 1 Any facility of the computing system or operating system required by a job or task and inc
62. as the user types in it Identifying Last Selected Item 112 Answer For our application we would like to know what the last selected item in our multiple select list was We need this because the user can press a button that will open a detailed view on that item would like to see an attribute such as last item selected Any ideas how to achieve this There is no public attribute available on the multiple select list part that will tell you the last item selected However with a tiny bit of code you can get this information Here is what you can do First connect the aboutToOpenWidget event of your window to the following script Smalltalk addCallbackToList Set up a callback for the multiple selection list self subpartNamed Multiple Select List1 widget addCallback XmNmultipleSelectionCallback receiver self selector multipleSelect clientData callData clientData nil VisualAge for Smalltalk Handbook Fundamentals Then add an instance variable to your visual part s class definition called lastltemSelected with the appropriate get and set methods Now write the following script to maintain your lastltemSelected value Smalltalk multipleSelect widget clientData clientData callData callData Save the last item that was selected The includes logic will exclude any items that were deselected since itemPosition will return the last item either selected or deselected
63. click a button to toggle a boolean Yes but only for the container as AbtTableView does not support this Intercept the aboutToBeginEdit event and set the edit policy See the initializeChildrenAttributeList method in AbtContainerTreeChildrenAttributesPage for an example You would specify EwToggleButtonEditPolicy as the edit policy and initialize it appropriately Chapter 3 Graphical User Interface 119 Adding Records to Container Question How do add more records to a container after the user presses the page down key The packetRequested event is not signaled until an at request comes into the BufferedCollection and is indexing into a slot that does not have a value Do you know if this is occurring What is happening How many rows have you told the container that the virtual collection has Changing Labels Question How can change the color of the label that appears with an icon Below is an example of using the AbtContainerlconListView hover help on parts palette shows Container Icon List 1 Add acontainer icon list to your visual part 2 Create a script aboutToOpenProcessing to add a callback handler to do the background drawing See the sample code at the end of this message 3 Implement the appropriate callback method drawBackground This method will be called twice once for the icon image and once for the label 4 Add a connection from your visual part aboutToOpenWidget event to the script abou
64. could type 1800 new line characters much more than the 30 lines maximum we want If a multiline editor part is not usable any suggestions You are correct there is no way to set the number of lines a user can enter into a multiline editor part only the total amount of text You could however write a script that does this type of checking and formatting You would need to invoke the script every time the user presses a key The script could determine the number of lines in the multi line editor part by keeping a count of the number of line delimiters entered in the multiline editor part s text The script could also force a new line if the user has typed in 60 characters but failed to hit the new line key Disabling a Button 156 Answer Suppose you have a text entry part and an add button How can you disable the add button whenever there is no text in the text entry part If the text entry part is connected to the selected item in the list part you can connect the button s enabled attribute to the selectionIsValid attribute of the list If the button is independent of the list you have to write a small script and connect a string event string in the text entry part has been changed to the script You should probably set the button to be disabled initially from the settings notebook for the button The sort of script you need is VisualAge for Smalltalk Handbook Fundamentals Smalltalk setButtonForString aSt
65. creating your own view with your message then displaying it as a dialog like this Chapter 3 Graphical User Interface 139 Smalltalk myView openApplicationModalWidget suspendExecutionUntilRemoved myView result ifTrue The result method is implemented by your view and is the result of the user s selection probably saved in an instance variable Visual Part Reuse Question Can reuse my visual parts Yes by creating reusable forms Create a new visual part then select and delete the default window Add a Form and make it the primary part Lay out your GUI design and add in any functionality you like Save the part and add it to the palette for everyone to reuse You can also reuse menus Supported Image Formats Question What are the image formats that VisualAge for Smalltalk supports Individual bitmap files and icon resources in DLLs work for push button images and for wallpaper You can also have individual graphic files Open the settings on the button and choose label type Graphic graphic type Image and enter the filename should be path relative to your VisualAge directory Enter a text label first if you are using hover help since the text for the button is what appears Click Sensitive Bitmap Questioni How do display a bitmap and then sense mouse clicks over it Look at the Graphic Link example AbtGraphicLinkView in the VisualAge Help Example feature It uses Smalltalk code to trac
66. enabled action of the push button Then go into the settings of the connection select the set parameters button and set the value to true check the value box This causes the push button to be disabled until any text is entered in the text box The push button then remains enabled If you want the push button to again become disabled for whatever reason you would have to write script for that Which leads to the next example The second example starts off exactly like the first example The view contains a textbox and a disabled push button This push button will remain disabled until text is entered into the text box and the text box loses focus as when you tab out As soon as the text box loses focus with text entered into it the push button becomes enabled If you then go back to the text box delete the text and tab out of it then the push button becomes disabled again and will remain disabled until text is entered into the text box This is accomplished by writing a small script that looks something like this VisualAge for Smalltalk Handbook Fundamentals Smalltalk enableButton info info self subpartNamed Text string info isEmpty ifTrue self subpartNamed Push Button enabled false ifFalse self subpartNamed Push Button enabled true You would connect the losingFocus event of the text box to this script Event Handling in Windows AIX and OS 2 Tip OS 2 does n
67. files files OrderedCollection new self filesMatching pattern on pathName do fileName files add fileName files File Existence Questioni How do I check in Smalltalk if a file exists Use the methods provided above to determine if a file exists Chapter 4 IBM Smalltalk Programming Language 177 Smalltalk fileExists fileName on pathName Answers whether or not the file name file name exists on the path named pathName self filesMatching fileName on pathName notEmpty Accessing COM Ports Question What is the correct way to access a COM port from Smalltalk Are there special classes or do have to use C for that There are no special classes for that in Smalltalk but you can directly use 1OCtl from Smalltalk without any C code For example if you want to know how many bytes are on the input queue use a script like this Smalltalk inputQueueCount rc fileDescriptor queueLength queueLength ByteArray new 2 fileDescriptor deviceFile fileDescriptor rc fileDescriptor dosDevlOCtl loctlAsync function AsyncGetinquecount pParams nil coParmLenMax 0 pcbParmLen nil pData queueLength cbDataLenMax queueLength size pcbDataLen nil rc 0 ifFalse AbtError new OSType fromBytes queueLength asInteger where you get the deviceFile with 178 VisualAge for Smalltalk Handbook Fundamentals Smalltalk open portName Perform
68. following the example on page 124 of the IBM Smalltalk Programmer s Reference 102 visualAge for Smalltalk Handbook Fundamentals Icon as Cursor Questioni How can I use an icon as cursor The follwing code snippet reads an icon out of a DLL and uses it as a cursor Smalltalk window data pixmap cursor shell label icon gc image shell CwTopLevelShell createApplicationShell shell argBlock w w title label example shell width 200 height 200 gt be y 1 label shell createLabel label argBlock nil label labelString this is a label label manageChild shell realizeWidget window shell window get an icon from a file icon Cglcon fromResource 153 fileName d v3clientdllabticons dll Chapter 3 Graphical User Interface 103 104 Smalltalk continued create a pixmap from the icon pixmap window createPixmap icon width height icon height depth 1 get device independent image image icon shapelmage gc pixmap createGC 0 values nil create a rectangular area of data for the cursor pixmap putDevicelndependentimage gc image image srcRect 000 extent image extent destRect 000 extent image extent Create the cursor hardcoded a hotspot at 20 20 A better idea might be to use image width and image height cursor pixmap createPixmapCursor pixmap x 20 y 20 pix
69. for Smalltalk and Version 4 0 increases that choice fivefold New UNIX platforms HP UX V10 10 and Sun Solaris V2 5 have been added and additional versions of PC operating systems are now supported OS 2 Warp V4 0 and Windows NT 4 0 Finally Smalltalk applications can be written for the S 390 MVS platform by using the new VisualAge Smalltalk Server for MVS product in conjunction with VisualAge for Smalltalk Version 4 0 With Smalltalk on the S 390 MVS system mainframe programmers can achieve the same level of productivity and capability as those using Smalltalk on a PC or workstation Using Chapter 1 What Is VisualAge for Smalltalk 15 16 Server Smalltalk for MVS you can quickly build business logic in true object oriented form on the MVS operating system Support for IMS CICS DB2 native file system access and batch programing are just a few of the features included State of the art cross development tools allow you to develop the bulk of the application on a PC and later deploy it to MVS for the robust run time performance we all expect from that platform You can now create end to end enterprise objects from client to mid tier server to third tier server using a single language and development environment For more information please see the white paper titled Introducing VisualAge Smalltalk Server for MVS For those of you who use the Windows platform Version 4 0 adds additional power and function A new OLE applicatio
70. height and border width using OSCall gt gt winQuerySysValue for example Smalltalk PlatformGlobals at HwndDeskTop winQuerySysValue PlatformConstants at SvCytitlebar should return you the title bar height Chapter 3 Graphical User Interface 93 Iterating over Widgets Answer How do iterate over all widgets in a window Use recursiveViewsDo instead of components do against the main window This will ensure all widgets are touched it is necessary when adding callbacks to a window in Windows Modal Dialog Questioni How can get my modal dialog to return a value suggest adding an instance variable called result to your view and implementing a prompt method Smalltalk prompt result nil self suspendExecutionUntilRemoved result You would open the view like this Smalltalk view MyView new openApplicationModalWidget myResult view prompt Capturing the Minimize Request Question Is there a way to capture the minimize request similar to the CloseWidgetRequest do not want a window to minimize to the desktop would like to create a pseudo desktop within my application and minimize to it 94 VisualAge for Smalltalk Handbook Fundamentals Answer You get notified but cannot disallow it Answer Window Synchronization Questioni How do open a window from one method and wait on a return from the window in the method Try the f
71. in Progress Window 155 Progress Messages inie a eta Sg eee a e ed 156 Limiting the Number of Lines in Multiple Line Editor 156 Disabling a Button 204 804 A 156 Accelerator Keys 2 2 0020 Fe ee 157 Hover Help on Widgets 0 000 eee ee 157 Improving Performance 0 020002 eee ee 158 Tabbing Order 1 aaa 158 Ctrl Click Events socn sopa ena a o 159 Creating Push Buttons 0 0000000 pee 160 Changing Part Labels 0 000000000202 2s 160 Adding BMP Files to Buttons 0 020000 4 161 Creating a Prompter 0 e 161 Setting Focus to Next Entry Field 02 162 Missing Carriage Return in Multiple Line Editor 162 Action on PFkey Pressed 0000 a 163 Chapter 4 IBM Smalltalk Programming Language 165 Smalltalk BOOKS 2 2 2 49 aia be ee a eee ee OS 165 Smalltalk Standardization 2 020000 0 0004 166 HH Construct uo ta dela hw it hod 4 A ee he By ted Mol ce 167 Taking Actions Automatically at Class Recompilation 168 Weak Pointers 0 e ee es 170 Utility of Weak Pointers 0 0000020 2 170 Object Finalization i spes so Tun perus ar Be A Oe RR eR eR es 171 Standard Methods not in API Category 172 Using the Correct Variable Type 0000 172 Smalltalk printf like Formatter
72. is Button1Mask and the key pressed is Ctrl execute your mouse button Ctrl code Here is what the code would look like Smalltalk event state Buttoni Mask 8 event keysym XKControlL mouse button Ctrl logic Chapter 3 Graphical User Interface 159 Creating Push Buttons Questioni How do create push buttons on the fly You have two different approaches 1 You do it in pure Smalltalk starting from the parent part such as an AbtFormView you do Smalltalk lt part gt widget createButton myButton argBlock nil manageChild In the argBlock you could specify the widget attachments The disadvantage is that this will leave you without an AbtButtonView part which may be inconvenient 2 The other method is adapted from the abtBuildInternals method Smalltalk lt part gt subpartNamed button put tVar AbtButtonView newPart tVar openWidget The openWidget will actually draw the button To position it properly you might add a framingSpec look into abtBuildInternals of a visual part for an idea of how to do that If that does not satisfy you add the maximum amount of buttons in the Composition Editor and use the hide show protocol to dynamically hide and show your buttons For buttons you need initially invisible you send a hide attached to the aboutToOpenWidget event of your window so they won t show Changing Part Labels Questioni How do change the labe
73. new point is answered All variables that pointed to the point still point to it with its new value Small integers Small integers are immutable because they are encoded directly in the object pointer This is an optimization and not something esoteric in the basics of OOP or Smalltalk It is a hack but one that provides a huge gain in performance Ideally such optimizations should go unnoticed and this one almost does It requires some bit of odd code to tell when an integer is a small integer or where the boundary is with large integers See IBM Smalltalk The Language for some code The encoding in current Smalltalk systems usually takes 2 3 bits of a 32 bit address for flags With two bits 30 bits are left for encoding an integer However this internal representation is never accessible to Smalltalk code Users even those who dig into the innards see just integers the class may differ depending on the size but the direct encoding into an object pointer is never seen This is also true with characters which are often encoded in the object pointer as well Adding Now when it is time to add say 1 to a small integer the encoded value is converted into a regular hardware integer value 1 is added and the result is converted back into some kind of integer The answer is always a new object Chapter 4 IBM Smalltalk Programming Language 241 Characters cannot be added to but they do have a value that can be converted to
74. pool at CATALOGNAME ifAbsent isNil ifFalse catFiles add catName cat mprName eachApp abtNlsRawFilename isEmpty ifFalse mprFiles add AbtNLSCoordinator resolveLanguageMappingCharacter mprName Chapter 2 General Information 77 Smalltalk continued work Transcript bringToFront work cr nextPutAll The required message files for instructionClass name cr cr nextPutAll Cat files cr catFiles isEmpty ifTrue work tab nextPutAll No cat files needed cr ifFalse catFiles asSortedCollection do each work tab nextPutAll each cr work cr nextPutAll Mpr files cr mprFiles isEmpty ifTrue work tab nextPutAll No mpr files needed cr ifFalse mprFiles asSortedCollection do each work tab nextPutAll each cr Required CAT and MPR Files for a Reduced Run time Image Tip The following script can be run to determine the cat and mpr message files that are needed by a reduced image at run time It reads the spusage es file produced by packaging so you should run the script right after your packaging run so that you have the correct spusage es file available The required run time message files will be listed on the Transcript 78 VisualAge for Smalltalk Handbook Fundamentals Smalltalk spusageFile fileStream class classCollection appCollection catFiles mprFiles work icxFileName
75. portability Unlike other portable implementations that emulate objects on various platforms IBM Smalltalk applications automatically take on the look and feel of target platforms by using the native platform widgets Unlike simple check in and check out library systems IBM Smalltalk team support includes an object repository true version control and configuration management capabilities Do you have a vendor program similar to Digitalk s and Powersoft s that encourages third party vendors to build parts that can be utilized with VisualAge We have published a Construction from Parts architecture that teaches vendors and end users how to create their own parts IBM s Object Connection program for VisualAge encourages other companies to build components that enhance the applicability and value of VisualAge We are currently working with more than 100 corporate members who are marketing more than 50 products VisualAge for Smalltalk Handbook Fundamentals VisualAge for Smalltalk and VisualAge Generator Answer How would you compar VisualAge for Smalltalk and VisualAge Generator as client server application development tools VisualAge Generator provides a highly productive workstation development environment for traditional host based COBOL developers that exploit new object oriented technologies while not requiring an investment in additional skills training VisualAge Generator uses a 4GL COBOL like scripting language along wit
76. related to graphical user interface GUI GUI Architecture Question What GUI architecture does IBM Smalltalk use IBM Smalltalk has many advantages in its GUI implementation ParcPlace VisualWorks Smalltalk emulates all the supported operating systems GUls in Smalltalk that is it opens a window and does all the bit manipulation itself This makes it very flexible for cross system development but there is a performance overhead Digitalk now ParcPlace Visual Smalltalk uses more of the underlying operating system GUI for better performance but at the price of only supporting a common subset of GUI controls it s better with Version 3 but complex controllers still require quite a lot of work IBM Smalltalk maps the Motif GUI widgets onto the underlying operating system widgets This means you get a very rich kit to build your GUI but the widgets operate at near native speed You have the best of both worlds Mapping Widgets Across Systems Question How do map Motif widgets to Smalltalk widgets Each Smalltalk widget that maps to a Motif widget class must implement two class methods e platformWidgetClass platformWidgetGadget The XPlatformAdministration class gt gt initializeWidgetClasses method sets up global variables in PlatformGlobals used by each of these methods for example XmPushButtonWidgetClass These map a Motif widget class an address using the CwWidgetClassMappings variable of CwBasicWidget into a Sma
77. system unit a display a monitor a keyboard one or more diskette drives internal fixed disk storage and an optional printer PCs are designed primarily to give independent computing power to a single user and are inexpensively priced for purchase by individuals or small businesses Examples include the various models of the IBM personal computers and the IBM Personal System 2 computer physical connection The ability of two connectors to mate and make electrical contact In a network devices that are physically connected can communicate only if they share the same protocol physical file A description of how data is to be presented to or received from a program and how data is actually stored in the database A physical file contains one record format and one or more members physical unit PU In SNA a type of network addressable unit NAU A physical unit PU manages and monitors the resources such as attached links of a node as requested by a system services control point SSCP through an SSCP PU session An SSCP activates a session with the physical unit in order to indirectly manage through the PU resources of the node such as attached links pointer 1 An identifier that indicates the location of an item of data 2 A data element that indicates the location of another data element 3 A physical or symbolic identifier of a unique target polymorphism The ability of different objects to respond to the
78. the open action deviceFile CfsFileDescriptor open COM1 oflag ORDWR share ODENYNONE deviceFile isNil ifTrue CwMessagePrompter errorMessage Error opening COM1 You can read from COM1 with something like Smalltalk queueLength self inputQueueCount gt 0 ifTrue deviceFile read buf String new queueLength startingAt 1 nbyte queueLength self incomingData buf Catching Errors Questioni How do catch errors in Smalltalk To catch errors that are difficult or impossible to anticipate use the exception handling facilities provided by IBM Smalltalk The simplest form of exception handling involves catching errors which occur while attempting to evaluate a block Use this Smalltalk lt do something gt when lt error gt do signal lt handle the error gt The message when do when sent to a block evaluates the block If an error matching the first parameter occurs the exception handler will be invoked Chapter 4 IBM Smalltalk Programming Language 179 The first parameter describes the kind of error that can be trapped Potential values for this parameter can be found in the pool dictionary called SystemExceptions They are ExError Any error ExHalt A halt has been encountered e ExlndexOutOfRange An attempt to access a nonexistent array index e ExCFSError File system error The second parameter is a block that takes a sin
79. this before each test Smalltalk Smalltalk at GloballsTesting put true A walkback will occur only the first time the halt is encountered rather than every time Quickly Disabling Methods Tip To quickly make a method do nothing add this line Smalltalk true ifTrue nil 56 VisualAge for Smalltalk Handbook Fundamentals To quickly make a method forward its behavior to its superclass use this line Smalltalk true ifTrue super myMethodName In this way you do not have to delete or significantly modify a method when you want to change its behavior or bypass an unfinished portion Specifying Public or Private with TrailBlazer To quickly specify the public or private policy for a class select the class and in the lower area the properties area select the instance interface or class interface You can then easily make public or private assignments Browse and Find in the Pop Up Menu Here is a little tool that extends the development environment The tool adds two extra items to the pop up menu Browse and Find Browse is an intelligent browse you select the code in the pane and then make your choice The code you have marked is evaluated and the resulting class is determined If the class is a part the editPart message is sent and the VisualAge for Smalltalk editor is opened If the class is not a part the ordinary Smalltalk browser is opened Find brings th
80. to the undefineCursor script Note that the order of the two last connections is important 6 Test your part and enjoy Busy Cursor Questioni Can showBusyCursor in a development application be packaged with the user application The Programmers Guide to Building Parts for Fun and Profit suggests that you create two different applications Edit and Run You package only the Run applications when creating your packaged image The same applies to VisualAge for Smalltalk applications and parts themselves As AbtShellView gt gt showBusyCursor is defined in AbtRunViewsApp it is packaged into your run time image Note this Please don t be confused by similarity in the names of showBusyCursor and showBusyCursorWhile The method showBusyCursorWhile is an instance method of the class EmSystemConfiguration Its comment says Show the busy cursor during execution of aBlock The cursor is not changed if the graphics system has not been started The following code shows you another way you can change the cursor The example can be evaluated in a Transcript window 100 VisualAge for Smalltalk Handbook Fundamentals Smalltalk window cursor window Transcript shell window cursor CgDisplay default busyCursor window defineCursor cursor Delay forSeconds 5 wait window undefineCursor By the way do not explicitly free this cursor As for disabling the mouse you might want to co
81. unload dialog The products and sys parameters are no longer used The new productld parameter is used to determine whether a feature is for evaluation or for production If you use sdcs00000023 for the value of this parameter your evaluation status will track with the evaluation status of the base VisualAge product If you use an unrecognized string for this parameter your component will always be treated as for evaluation For the platforms parameter aix has been replaced with unix e Prerequisite loading Prerequisite features are indicated with the include statement referencing the ctl file of the prerequisite There is one include statement for each direct prerequisite feature In this example SOMsupport Base for IBM Smalltalk and VisualAge Base are the direct prerequisite features of SOMsupport Base for VisualAge These two lines are equivalent to the second line in the Version 3 example e Feature loading The final two lines in the example identify the configuration maps comprising the feature Each line is composed of four parts Name of the configuration map to be loaded Time stamp of the configuration map to be loaded Name of the DAT file containing the code to be loaded Chapter 2 General Information 81 A comment typically the name and version of the configuration map to be loaded These two lines are equivalent to the third line in the Version 3 example To have your compone
82. you normally would use in addition to option xd0 For instance if your normal EMSRV startup options are emsrv v b50 It240 then you should use emsrv v b50 It240 xd0 Note that when you use xd0 you lose the protection mechanism that prevents you from starting EMSRV on an NFS drive To avoid corruption take extra care to ensure that you run EMSRV from a local hard drive when you start with this option Windows 95 Client From a Windows 95 client you must use Novell s Client32 for Windows 95 requesters and associated patches If you use the wrong requesters library corruption is possible The Client32 for Windows 95 requester and the required patches can be obtained from Novell s Web site From the Core OS Updates section select landr9 exe from the Client Kits amp Updates section select cltdr2 exe Because fixes may be updated or files renamed over time you may find that these files are no longer available In this case follow the instructions at the top of the page for accessing Novell s Product Support area If these two patches are not used users may experience severe performance problems when reading from attached servers and may also find that locks are not correctly released if more than one image is running concurrently on the same machine The two patches should correct both of these problems The Client32 for Windows 95 requester has many parameters that may be changed in the Advanced Settings dialog
83. you would with any VisualAge application Thus you can quickly add a Web client interface to your existing VisualAge for Smalltalk applications or rapidly develop a new Web client from scratch that leverages your existing relational data and transactions To the Web client support Version 4 0 adds a grid visual part ActiveX controls and JPEG images The server now supports DLL or shared library based interfaces for improved performance The new grid visual part enables you to build HTML tables The tables can contain an arbitrary number of rows and columns and cells of the table can contain other visual parts such as text buttons list boxes and forms Using the grid you can create clean well organized visually appealing Web pages that provide table based user interface layouts You can easily embed ActiveX controls on a page using the object tag JPEG images are also supported When these Version 4 0 enhancements are taken in combination with the existing Web client development capabilities you can create dynamic visually attractive Web clients In Version 4 0 server application performance is greatly improved over the CGI using DLL or shared library interfaces These interfaces streamline the startup of the server application because an operating system process does not have to be created for each request made of the server as it does with CGI The DLL or shared library interfaces are available in Web server products supporting IBM s
84. 0 ee 29 Environment Variable 0 a 29 Registered Connection 2 00 00 a 30 Loading Different Image 0 000 000 2s 30 Deferred Update Part 2 2 0 0 200220 05002048 30 Renaming a Visual Part 0 2 0 0 0 00000000005 31 Hover Help for Buttons 2 00000 a 32 Customizing Connection Menu 2 2202 0 2 2 02 33 Live Updating of Images e 33 Passing Parameters Between Windows 34 Generating Archival Code 0 o 34 Deleting Parts with Instances 2 2 24 35 Change Table Format 2 0 00 000 pe ee 36 Error Messages 3 3 2 win a ak Gee ee a wie Sars 36 Removing Archival Code 0 o 37 Apply Push Button ei er co ra e ia 38 INnSpector roza a E a ene a ORR SS 38 MultiMedia estic a add a eee tes 38 Default MEMORY ici E e a Gao Garin ew da a 39 Storing Settings eat aa A dt 39 Extending Classes 2 3 e aes bop ee Ge ek De eed E E ee ed 40 Running VisualAge from External SCSI Drive 2 40 Damaged Classes 0 e E ae e ia ee 40 Extending Classes e 41 Modifying the System Menu 0000002 epee 41 VisualAge for Smalltalk Handbook Fundamentals Organizer VIEWS s a gadeg we a eee ew a dak ada lie Bla ew Se g 42 Bileme seS a e a saree id dere ci ees Sdn e a tea AL Bee ds ie Hee 43 OS 25S HUTA O Winey a a Eee ent cabos 4
85. 127 class continued AbtRecord 62 AbtResultTable Vol2 167 AbtRowColumnView 109 AbtSampleLauncherView Vol2 140 AbtShellView 69 155 AbtTextConverterManager 152 AbtTextView 145 AbtTimeConverter 219 agent 65 alternatives 255 AS 400 record Vol2 3 AS400APPCConfiguration Vol2 33 AS400DataQueueEntry Vol2 6 AS400DirectFile Vol2 49 AS400KeyedFile Vol2 49 AS400RecordDescription Vol2 35 AS400RemoteCommand Vol2 53 AS400RemoteProcedureCall Vol2 36 AS400SequentialFile Vol2 49 Vol2 50 AS400System Vol2 18 available in library 257 BplBusinessObj Vol2 112 business 208 catalog Vol2 230 CfsDirectoryDescriptor 176 changes 255 changing 231 comparing 257 controller 65 creating from script 229 CwOverrideShell 98 damaged 251 DatabaseAccessSet Vol2 192 Date 212 date stamp 247 Delay 197 delete old version 250 DsCallbackRec Vol2 196 DsDistributedSystem Vol2 202 DsTCPCommunicator Vol2 202 DsTracer Vol2 196 DtListBuilderCollection Vol2 209 E4AS400Broker Vol2 33 E4CommunicationService Vol2 54 E4FrameWorkApp Vol2 33 E4KeyedFile Vol2 61 class continued E4KeyedFiles Vol2 44 E4Service Vol2 17 Vol2 33 editions 249 EmFileOutinterface 28 EmLibraryStatistics 71 253 ensure packaging 49 EsLinearOrderedCollection 218 EwList 223 EwTableList 224 EwTextEditPolicy 224 extending 40 extending server Vol2 215 extension 40 49 64 facade 65 fixed decimal 182 generating with SOM prefix Vol2 238 hierarchy 172 identification 182 instance va
86. 3 Sorting SortedCollections Answer In Digitalk Smalltalk SortedCollection includes the method reSort I m trying to implement my own reSort method Smalltalk reSort newColl size 0 ifTrue self newColl self species new size newColl sortBlock self sortBlock newColl addAll self elements newColl elements However this method produces random results the contents of the SortedCollection don t get sorted Am missing something Yes you get the same result if you evaluate the following code ina Workspace Smalltalk newColl coll coll andi boris vincent asSortedCollection newColl coll species new coll size newColl sortBlock coll sortBlock newColl addAll coll coll elements newColl elements coll But now try this 194 VisualAge for Smalltalk Handbook Fundamentals Smalltalk newColl coll coll andi boris vincent asSortedCollection newColl coll species new coll size newColl sortBlock coll sortBlock newColl sorted true newColl addAll coll coll elements newColl elements coll Now the resulting collection gets sorted Compiler Severity Level Answer How do control the compiler warning severity level You must have the TrailBlazer loaded and enabled From the TrailBlazer pulldown menu select Options Compiler Warning Level Finding the Sender Signature Answer How
87. 3 BRW Format Generator 0 020200 00004 43 Loaded Methodi tener be Se le eek eee oe SE ae 44 Missing Character Set 00 0000 0 p ee ee 44 Event Triggering ii Bi Bae ew RA GA ee A DA eB Gee 44 Part not Visible aa e ea a SA das Sp atl Ee Gl AS 45 Removed Class comida iaa ae ae a ee ee eS 45 Synchronizing Attributes 2 2 0 200202000000 45 Keeping the Packaged Image Small 46 Including Classes in a Package 0 2000004 46 Packaging for AIX from OS 2 6 5 sw ww o 47 Loading Application in a Run time Image 47 Packaging an Application for Windows 48 Iconsand DELLS arts e co wk de a amp Aue de dei dr dobbs 48 Packaging a Workspace 0 000202 pete 48 Image Reduction 2 e g Boe Roe Ga a ee an ee 48 Ensuring that Needed Classes are Packaged 49 Class Modifications and Packaging 04 49 Merging Application Files into Run time Image 49 MISSING ICONS fot id Sd qa aot Gale Bares 50 Required CATFiles cn c0 ans th donde a My ds a de Soe an pang 50 Packaging Pool Dictionaries 0 2 51 Application Prerequisites 0 2 0 0 000020 ee 52 Missing Classes in the Run time Image 52 Missing Method in Package e 53 Run time Image Packaging Problem 54 Generating Getters and Setter
88. 43 file system 180 MCHO0802 Vol2 34 NetBIOS Vol2 70 opening proc dialog Vol2 72 ORA 00942 Vol2 177 primitive 73 Vol2 97 readAll method Vol2 44 return code 72 saving part 69 security Vol2 199 somFindClass Vol2 243 SQLO236W Vol2 188 SQLO805N Vol2 173 SQLSTATE 37000 Vol2 123 SQLSTATE S1010 Vol2 124 successor uniqueness violation Vol2 109 swapper 198 SYS317x 72 TCP IP startup Vol2 210 terminating SOM Vol2 241 time out Vol2 111 transaction abend Vol2 72 turning off message 135 user input 133 Win32s Vol2 226 error message displaying 36 explanation 68 escaping infinite loop 27 Ethernet Vol2 10 EtWorkspace 48 event aboutToOpenWidget 93 110 changed 213 Ctrl key and click 159 defaultActionRequested 70 double triggering 213 errorOccurred Vol2 72 gettingFocus 102 handler enter key 153 function key 143 keyboard 142 159 230 platform 151 Index 317 event continued itemChildrenRequested Vol2 62 itemCollapsed 259 itemExpanded 259 key pressed 230 losingFocus 102 not trappable 230 profiler 21 registered 260 registering 225 resized 96 selectediIndexChanged 110 selectedltemsChanged 117 selectionChanged 105 106 triggering 44 userlnputConvertError 133 userModified 141 EwDropCallbackData 144 exception doesNotUnderstand 228 process stack 199 exception handling catching errors 179 code 182 database code Vol2 119 debugging DLL Vol2 86 doesNotUnderstand 228 object space connection Vol2 196 open file 208 SOM
89. 46 packaging prerequisites preventing growth 25 rebind strings 75 reduced runtime 47 78 reducing size 23 25 232 remote Vol2 209 remote object space pointers required CAT files 50 run time 200 205 264 saving Vol2 35 saving before packaging 26 50 size 24 48 54 stock 47 50 synchronizing 243 50 140 95 Vol2 209 30 39 49 Vol2 22 52 Vol2 219 image continued update 249 using iterator field break Vol2 226 using phantom instance variables Vol2 113 virgin 23 wallpaper 138 immutable object 240 importing application 245 IMS communication Vol2 114 harclock Vol2 110 LU2 identification Vol2 109 screen scraping Vol2 111 stacked processing Vol2 114 transaction modeling Vol2 112 in place activation 260 in progress window 155 inactivity log off 202 including classes in package 46 incremental compiler 191 indexed message editor 62 inetd Vol2 73 infinite loop 27 Informix 8 inheritance RECORD subclass Vol2 48 script 204 visual class 215 visual part 204 inherited message 175 inhibiting list selection 223 initializing class variables 209 input error 133 validating 118 inspector opening 38 performance Vol2 19 installation AS 400 Connection Vol2 23 installing feature 253 instance equality 226 garbage collection 211 identity 226 phantom variables Vol2 113 removing Vol2 209 sharing across object spaces Vol2 207 instance continued testing 173 integer as key 235 hash 235 internal representation 216
90. 5 7 An Introduction to Object Oriented Programming amp Smalltalk Lewis Pinson amp Richard Wiener Addison Wesley 1988 ISBN 0 201 19127 x 1997 165 Object Oriented Design with Applications Grady Booch Benjamin Cummings 1991 ISBN 0 8053 0091 0 A Quick Trip to ObjectLand Object Oriented Programming with Smalltalk PTR Prentice Hall 1993 ISBN 0 13 012550 4 IBM Smalltalk The Language David N Smith Benjamin Cummings 1995 ISBN 0 8053 0908 X IBM Smalltalk Programming for Windows and OS 2 Dan Shafer and Dan Herndon Prima 1995 ISBN 1 55958 749 0 Smalltalk with Style Suzanne Skublics Edward J Klimas and David A Thomas Prentice Hall 1996 ISBN 0 13 165549 3 Question What books or reports about Smalltalk are available from IBM besides product documentation Answer Object Oriented Design A Preliminary Approach IBM 1990 GG24 3647 Developing a CUA Workplace Application IBM 1991 GG24 3580 Object Oriented Analysis of the ITSO Common Scenario IBM 1990 GG24 3566 Cooperative Processing in an Object Oriented Environment IBM 1991 GG24 3801 A Practical Introduction to Object Oriented Programming IBM 1992 GG24 3641 01 Smalltalk Portability A Common Base IBM 1992 GG24 3903 Object Centered Environments for Smalltalk IBM 1990 RC 15548 The Geometry Browser A Feature Modeler in Smalltalk IBM 1990 RC 15394 Smalltalk Standardization Questioni What is going on with the effort to standardize Smallt
91. 8 platforms 6 porting applications 10 replacing icon 27 resource catalog 12 running from external SCSI drive 40 stability 2 starting 71 support xix 11 TalkLink 11 upward compatibility 10 Windows Vol2 4 VisualAge Generator 5 visualization feature 82 visualizer 6 W walkback capturing information Vol2 213 looping 56 wallpaper 138 watch field Vol2 230 weak pointer 170 Web Connection AppletAuthor 22 CGI 20 ICAPI 20 ISAPI 20 JPEG 20 NSAPI 20 where clause Vol2 125 Vol2 133 widget attachments 95 circular reference 97 closing 96 dependent attachments 97 destroying 95 widget continued hover help 157 iterating over 94 key release 134 list 223 locating focus 136 mapping across systems 87 native presentation manager Vol2 94 updating 191 view wrapper 146 wildcard Vol2 140 Win32s 70 Vol2 226 window always on top 98 border 93 centered 93 closing 95 134 closing on PF key 163 Esc key 134 find active 155 in task list 131 in progress 155 iterating over widgets 94 location 90 log on Vol2 3 maximizing 91 minimizing 94 minimum size 96 moving icons 152 opening centered 93 opening maximized 92 palette 131 position 93 positioning at cursor 90 progress indicator 137 size 96 space planning 93 synchronization 95 title 131 title bar 93 Windows 16 bit Vol2 62 AS 400 application Vol2 4 code page conversion 266 database support Vol2 181 DBCS Vol2 255 disk space 261 Windows continued d
92. 82 SOM CORBA Vol2 239 development toolkit Vol2 244 DSOM hanging system Vol2 239 environment variable Vol2 241 SOM continued exception Vol2 239 feature Vol2 244 generating class with prefix Vol2 238 inout sequences Vol2 244 interface repository Vol2 245 LIBPATH Vol2 243 missing class definition Vol2 243 object Vol2 245 object as part Vol2 240 OS 2 desktop Vol2 246 prefix Vol2 238 terminating error Vol2 241 wrapper Vol2 240 Vol2 245 sorted collection 194 SoundBlaster 85 space planning window 93 SQL ANSI support Vol2 140 AS 400 database Vol2 5 Vol2 11 building statement Vol2 148 cursor Vol2 179 dynamic where clause Vol2 125 embedded Vol2 121 error 30081n Vol2 120 error 37000 Vol2 123 error S1010 Vol2 124 exception handling Vol2 119 for update of Vol2 127 host variable with wild card Vol2 140 IN clause Vol2 146 INSERT Vol2 160 Jet driver Vol2 127 locked row Vol2 145 ODBC Vol2 32 ODBC requirements Vol2 6 outer join Vol2 146 performance Vol2 48 statement Vol2 143 trace Vol2 164 wild card Vol2 140 SQL Server 8 Vol2 185 stability VisualAge 2 stack aborting process 199 frames 196 information capturing 28 Index 333 stack continued overflow 72 trace Vol2 213 stacked processing Vol2 114 static communication session acquisition Vol2 114 SQL 18 stock image 47 50 stored procedure Vol2 32 Vol2 146 Vol2 156 Vol2 185 Vol2 193 storing settings 39 stream 237 Vol2 70 strin
93. AGE Redbooks Home Page on the World Wide Web http w3 itso ibm com redbooks IBM Direct Publications Catalog on the World Wide Web http www elink ibmlink ibm com pb1 pbl IBM employees may obtain LIST3820s of redbooks from this page REDBOOKS category on INEWS Online send orders to USIB6FPL at IBMMAIL or DKIBMBSH at IBMMAIL Internet Listserver With an Internet e mail address anyone can subscribe to an IBM Announcement Listserver To initiate the service send an e mail note to announce webster ibmlink ibm com with the keyword subscribe in the body of the note leave the subject line blank A category form and detailed instructions will be sent to you Copyright IBM Corp 1997 275 How Customers Can Get ITSO Redbooks Customers may request ITSO deliverables redbooks BookManager BOOKs and CD ROMs and information about redbooks workshops and residencies in the following ways 276 Online Orders send orders to IBMMAIL Internet In United States usib6fpl at ibmmail usib6fpl ibmmail com In Canada caibmbkz at ibmmail Imannix vnet iobm com Outside North America dkibmbsh at ibmmail bookshop dk ibm com Telephone orders United States toll free 1 800 879 2755 Canada toll free 1 800 IBM 4YOU Outside North America long distance charges apply 45 4810 1320 Danish 45 4810 1020 German 45 4810 1420 Dutch 45 4810 1620 Italian 45 4810 1540 English 45 4810 1270 Norwegian 45 4810
94. AP developer assistance program DBA database administrator DBF database file DBMS database management system DB2 Database 2 Copyright IBM Corp 1997 DDCS DDL DDM DDS DLL DSN DSOM ECS EPI ESA FTP GIF GPF GUI HLLAPI HPFS HTML HTTP HTTPD IBM IDL distributed database connection services database definition language Distributed Data Management data description specifications dynamic link library data set name distributed system object model electronic customer support external presentation interface enterprise systems architecture File Transfer Protocol graphic interchange format general protection fault graphical user interface high level language application program interface high performance file system Hypertext Markup Language Hypertext Transfer Protocol Hypertext Transfer Protocol daemon International Business Machines Corporation interface definition language 305 ILE IMS IPC IPMD ISO ISP ISV ITSO JDBC LAN LF MB MIME MLE MQ MRI Mvs NLS NT ODBC OIDL OLTP 306 VisualAge for Smalltalk Handbook integrated language environment information management system inter processor communication IBM presentation manager debugger International Organization for Standardization Internet service provider independent software vendor International Technic
95. AS 400 Redbooks Collection SBOF 7270 SK2T 2849 RS 6000 Redbooks Collection HTML BkMgr SBOF 7230 SK2T 8040 RS 6000 Redbooks Collection PostScript SBOF 7205 SK2T 8041 Application Development Redbooks Collection SBOF 7290 SK2T 8037 Personal Systems Redbooks Collection SBOF 7250 SK2T 8042 Other Publications 272 These publications are also relevant as further information sources e VisualAge for Smalltalk User s Guide SC34 4518 e VisualAge for Smalltalk Programmer s Guide to Building Parts for Fun and Profit SC34 4496 e IBM Smalltalk Programmers Reference SC34 4493 e IBM Smalltalk Users Guide SC34 4536 e IBM Smalltalk The Language by David N Smith Benjamin Cummings Publishing Company ISBN 0 8053 0908 e VisualAge and Transaction Processing in a Client Server Environment by Andreas Bitterer Michel Brassard William Nadal and Chris Wong Prentice Hall PTR 1996 ISBN 0 13 460874 7 AS 400 Application Development with VisualAge for Smalltalk by Andreas Bitterer Masahiko Hamada John Oosthuizen Gino Porciello and H kon Rambek Prentice Hall PTR 1997 ISBN 0 13 520453 4 e World Wide Web Programming VisualAge for C and Smalltalk by Andreas Bitterer and Marc Carrel Billiard Prentice Hall PTR 1997 ISBN 0 13 612466 6 e Object Oriented Application Development with VisualAge for C for OS 2 by Marc Carrel Billiard Peter Jakab Isabelle Mauny and Rainer Vetter Prentice Hall PTR 1996 ISBN 0 13 242447 9
96. ActionRequested event of a text box How do fix it This is a known problem You ll need to change the method postCreationInitialization in AbtTextView Locate the following piece of code in the method and remove it Smalltalk widget addCallback XmNactivateCallback receiver self selector defaultAction clientData callData clientData nil Reusable Table Part Questioni How do create a reusable table part with different widths Promote the width attribute of each column so it becomes an attribute of the reusable part You should be able to change the width through the settings of the reusable part or via a script The width cannot be changed with the mouse because embedded parts are treated as singular primitive objects Trap the Enter Key for Tabbing Question want to add a callback XmNactivateCallback to a toggle button so that can trap the Enter key to do the tabbing Would this be the right way to do this To do this use an event handler rather than trying to add a callback not supported by the widget The following example sets up four toggle buttons in a view Run the following script when the openedWidget event fires Chapter 3 Graphical User Interface 153 Smalltalk setUpEventHandlers tog1 tog2 tog3 tog4 tog1 self subpartNamed Toggle Button1 yourself tog1 primaryWidget addEventHandler KeyPressMask receiver self selector tabTo2 clientData event
97. As part of the infrastructure this layer contains class extensions made to the base product As part of the infrastructure this layer contains in house development tools for developers These classes are never packaged with the end user application As part of the infrastructure this layer contains common services defined in the Common Object Request Broker Architecture CORBA for example the persistence object service concurrency and transaction service VisualAge for Smalltalk Handbook Fundamentals Class Name Suffix For a class the category of component is defined with the third letter of its prefix and the use of a suffix Model Class Model classes for example business domain classes do not need a suffix Reusable Visual Classes Reusable visual classes are derived from model classes There is a one to many relationship between one model class and its reusable visual classes and that is why we always use the name of the model class as the name of the reusable visual class lts suffix consists of two parts e The first part characterizes the information being displayed Use a name that characterizes the reusable visual class based on the attributes displayed from its model class Consider using terms like the following Summary Detail e The second portion is the word View Visual Classes Visual classes are task oriented and should reflect in their name their main task Use View for suffix Facade Clas
98. COM port 178 action closeLibrary Vol2 98 closeWidget 25 95 default 113 destroyPart 95 activator Vol2 199 Vol2 203 active terminating processes 25 ActiveX 14 adding column to table 146 container icons dynamically 126 icon to list 129 items to combo box 110 menu choices 105 records to container 120 agent class 65 AIX calling C function Vol2 103 DB2 6000 Vol2 119 DB2 6000 binding Vol2 121 DDE Vol2 108 distributing application 252 event handler 151 moving library to 255 MQSeries Vol2 73 packaging 47 reports feature Vol2 225 simplified Chinese 267 Copyright IBM Corp 1997 altering behavior 40 anchor block handle 135 animated busy cursor 105 ANSI Smalltalk committee 2 standardization 166 SQL Vol2 140 Anynet Vol2 51 API break Vol2 138 common file system 176 data queue Vol2 40 DosStartSession Vol2 84 EHNAPPC_QuerySystems Vol2 17 MQ Vol2 76 nonblocking Vol2 91 OS 2 PMs Vol2 88 router Vol2 4 system Vol2 50 APPC AS 400 configuration Vol2 33 AS 400 connection Vol2 35 Vol2 50 ASCII work station controller Vol2 4 blocking factor Vol2 15 LU 6 2 Vol2 9 proc dialog Vol2 71 router Vol2 35 stack Vol2 51 AppletAuthor 22 application AS 400 native Vol2 8 packaging Vol2 8 Vol2 21 runtime prerequisites Vol2 9 changing database name Vol2 174 CICS Vol2 72 COBOL Vol2 71 creating new 250 delete 249 distributing 252 edition 246 editions browser 250 307 application continued exporting 245 exporting t
99. Copy is another example Is there some reason why these messages are not in an API category The Smalltalk Programmers Reference says about deepCopy Unlike other Smalltalk implementations CLDT does not provide a public default version of either deepCopy or shallowCopy in Object protocol The semantics of both these messages are normally specific to each class and often to an application The categorization for value has been taken care of for the next release Note also that Block is an abstract superclass Using the Correct Variable Type Question If want many different methods to use a dictionary should have the following code Smalltalk SomeName Dictionary new 172 VisualAge for Smalltalk Handbook Fundamentals and assign the SomeName to be a global variable Is this the correct way of doing it guess the very first time it will ask me if would like to make SomeName a global variable If those methods are all instance methods on the same class then you would store the dictionary in an instance variable Otherwise you might want to make it a class variable with a public get method That way your global name space does not get overloaded Smalltalk printf like Formatter Questioni Is there any code available that does string formatting like printf in C You might want to check out EsString gt gt bindWith and all its variants in IBM Smalltalk It s good for the case where yo
100. Hiding and Showing Pages Questioni How do I hide and show pages of an OS 2 Windows notebook believe hide is not supported for notebook pages you must destroy the 116 page Here is how add a page dynamically basically copy from the abtBuildinternals method and add an openWidget send Smalltalk addNotebookPage aNotebook named aName page label aNotebook subpartNamed aName put page AbtPortableNotebookPageView newPart page framingSpec AbtViewAttachmentConstraint new leftEdge AbtEdgeConstant new offset 34 topEdge AbtEdgeConstant new offset 90 page subpartNamed label put label AbtLabelView newPart label object Time now printString framingSpec AbtViewAttachmentConstraint new leftEdge AbtRunEdgeAttachmentConstraint new attachment XmATTACHFORM offset 65 rightEdge AbtRunEdgeAttachmentConstraint new attachment XmATTACHNONE topEdge AbtRunEdgeAttachmentConstraint new attachment XmATTACHFORM offset 95 bottomEdge AbtRunEdgeAttachmentConstraint new attachment XmATTACHNONE page openWidget label openWidget VisualAge for Smalltalk Handbook Fundamentals To remove the page call destroyPart on the page This is just a simplified example in your case you would substitute label for an embeddable view that represents the entire page Porting Notebooks across Platforms Question If you try to port an OS 2 Windows notebook from an OS 2 pl
101. Load your changes into the image and start working 3 Going from work to home version off the day s changes up to the application or map level and export them to a new library Zip it and put it on diskette Import the code into your home manager when you get back home Load your changes into the image and start working Don t worry about having Version 999 or whatever The only thing that matters is the name that you use to version the code when you ship If this is a psychological barrier then start your version numbers at 0 1 and let them grow to 0 nnn When you are ready to ship version it as 1 0 Versioning often is a good habit It makes for excellent checkpoints Versioning is a tool It is your friend Use it Shared Library Password Protection Answer Libraries 244 How do protect certain components of my library against unauthorized access For example in a university environment rather than sharing code students need to hide their work from other students The VisualAge for Smalltalk Professional Server is meant for sharing information but it does have password control You should be able to define a password for each student to limit their access to only their work in a common repository Then define an application for each student where they and their professor are the only group members This is covered in the VisualAge for Smalltalk User s Guide The Professional version of VisualAge for Smalltalk permits
102. NVY configuration management and version control system is included in the VisualAge for Smalltalk Professional and Professional Server products precluding the need to order a separate product and managing compatability between VisualAge and ENVY The October 9 1995 issue of InfoWorld states that IBM did a superb job weaving Object Technology Chapter 1 What Is VisualAge for Smalltalk 7 Inc s Envy Developer into VisualAge resulting in ummatched team development facilities Packaging Support Answer How does VisualAge for Smalltalk support packaging One of the enhancements to Envy found in VisualAge for Smalltalk is the one button packager which automatically excludes unnecessary classes from the application executable The developer can also customize what is stripped out of the image to provide an even smaller executable Database Support Answer Which databases does VisualAge for Smalltalk support VisualAge for Smalltalk supports a wide variety of database systems including the DB2 family for example DB2 2 for OS 2 DB2 6000 for AIX and on Windows using CAE client support Through connectivity services of DDCS VisualAge for Smalltalk can access the DB2 family including DB2 and SQL DS and access to the AS 400 Oracle ODBC with industry standard drivers such as Sybase SQL Server Informix IBM intends to respond to additional customer needs for native support for other databases In addition to any datab
103. Not Understand Format Menu on Windows NT 4 0 2 Back tabbing in Container Details Views Properties Views and Notebook Settings Views Code Page Conversion Errors Determining Required ICs Required CAT and MPR Files for an IC Run time Image Required CAT and MPR Files for a Reduced Run time Image Format Change for CTLs Unloading the Visualization Feature Manager Access 0 000 a Opening Multimedia Devices 2 Using Digital Video Player on OS 2 Video Disk Player 2 5 080005 22 Gs Crystal Wave and MWave Audio Cards AVA Playback Windows 2044 Lotus Notes usina o dea Ge a Chapter 3 Graphical User Interface GUILArchitecture sip megis wae eee a dea a Mapping Widgets Across Systems Motif Documentation 2 Interface to Windows 95 7 o Applications with Multiple Windows Exit Dialog Message Box 04 Window Location 0 2 2002 Positioning Window at Cursor Maximizing a Window 20 000 Opening Window Maximized Display Resolution lt s ccosa coe koperasi e 2 0 0 0 000004 Opening Window Centered 02 Window Space Planning 04 I
104. QwParent winSetWindowPos nil x O y O cx O cy 0 fl SwpMinimize Opening Window Maximized Questioni How can cause a window to be opened maximized Let s apply what we just learned Create a script like the following Smalltalk maximizeWindow Maximize window in OS 2 self primaryWidget osWidget handle winQueryWindow QwParent winSetWindowPos nil x O y O cx O cy O fl SwpMaximize Then create an event to script connection from the openedWidget event of the window to the script you just wrote and enjoy Display Resolution Questioni How can retreive the display resolution The following code snippet buys you the height and width of the screen Smalltalk screenHeight CgScreen default width screenWidth CgScreen default height 92 visualAge for Smalltalk Handbook Fundamentals Opening Window Centered Questioni How do open a window centered on the screen depending upon its resolution Connect the aboutToOpen Widget event of your window to a setPosition method which determines window position based on screen size Smalltalk setPosition w w self primaryWidget w x CgScreen default width w width 2 asInteger y CgScreen default height w height 2 asInteger Window Space Planning Questioni How do calculate the space taken up by the window border title bar and so on In OS 2 you can query the title bar height menu bar
105. SG24 4828 00 VisualAge for Smalltalk Handbook Volume 1 Fundamentals September 1997 International Technical Support Organization San Jose Center SG24 4828 00 International Technical Support Organization VisualAge for Smalltalk Handbook Volume 1 Fundamentals September 1997 Take Note Before using this information and the product it supports be sure to read the general information in Appendix A Special Notices First Edition September 1997 This edition applies to VisualAge for Smalltalk Versions 2 3 and 4 for use with OS 2 AIX and Microsoft Windows 95 NT Comments may be addressed to IBM Corporation International Technical Support Organization Dept QXXE Building 80 E2 650 Harry Road San Jose California 95120 6099 When you send information to IBM you grant IBM a non exclusive right to use or distribute the information in any way it believes appropriate without incurring any obligation to you Copyright International Business Machines Corporation 1997 All rights reserved Note to U S Government Users Documentation related to restricted rights Use duplication or disclosure is subject to restrictions set forth in GSA ADP Schedule Contract with IBM Corp Contents Preface citada 02 MASE AE YAS E a Se AE SR ey XV How This Redbook Is Organized aaa aaa xvi ITSO onthe Internet 2 2 0200200 0000000000000 040 xvii VisualAge Support on CompuServe xi
106. SI open systems architecture OSA A model that represents a network as a hierarchical structure of layers of functions each layer provides a set of functions that can be accessed and that can be used by the layer above it Note Layers are independent in the sense that implementation of a layer can be changed without affecting other layers Open Systems Interconnection OSI 1 The interconnection of open systems in accordance with specific ISO standards 2 The use of standardized procedures to enable the interconnection of data processing systems Note The OSI architecture establishes a framework for coordinating the development of current and future standards for the interconnection of computer systems Network functions are divided into seven layers Each layer represents a group of related data processing and communication functions that can be carried out in a standard way to support different applications operating system Software that controls the execution of programs An operating system can provide services such as resource Glossary 295 allocation scheduling input output control and data management operation 1 A defined action namely the act of obtaining a result from one or more operands in accordance with a rule that completely specifies the result for any permissible combination of operands 2 A program step undertaken or executed by a computer 3 An action performed on one or more data i
107. Smalltalk features some of which are packaged with the base product and some others are separately orderable Chapter 1 AS 400 Connection This chapter provides a discussion of the AS 400 Connection feature and related items such as ClientAccess 400 and DB2 400 VisualAge for Smalltalk Handbook Fundamentals Chapter 2 Communications Transactions This chapter provides a discussion of the Communications Transactions feature and its protocols such as TCP IP APPC CICS or NetBIOS Chapter 3 Interface to External Routines This chapter discusses the use of external routines such as C or COBOL programs Chapter 4 CICS and IMS Connection This chapter provides a discussion of the CICS IMS Connection feature Chapter 5 Database This chapter covers questions and answers related to database access from VisualAge for Smalltalk such as DB2 or Oracle Chapter 6 Distributed This chapter provides insight into the VisualAge for Smalltalk Distributed feature for example remote objects or object spaces Chapter 7 Reports This chapter covers the VisualAge for Smalltalk Reports feature Chapter 8 SOM DSOM This chapter provides a discussion of the System Object Model and the Distributed System Object Model Chapter 9 Web Connection This chapter discusses the Web Connection feature of VisualAge for Smalltalk ITSO on the Inter
108. TH x VISUALAG PATH SET HELP x VISUALAG HELP HELP SET ABTPATH x VISUALAG ABT In addition you ll need to update ABT CNF and NLS CNF I make the path references relative to the current directory Damaged Classes Questioni How do I get rid of damaged classes Version and release your classes applications and configuration maps Then get a fresh image and reload your stuff 40 VisualAge for Smalltalk Handbook Fundamentals Extending Classes Answer How do extend classes in the Organizer You can extend classes in the Organizer in one of two ways Both ways require you to be using full menus To get full menus click Full Menus from the Options pull down menu e Option 1 Select the application you want to extend the class into From the Parts menu click on New gt Extension and enter the name of the class you want to extend e Option 2 Select the class part you want to extend From the Parts menu click on Extend and enter the name of the application you want to extend the class into Modifying the System Menu Answer would like to modify the System Menu the menu you get when you click on the VisualAge icon at the upper left corner of a window for an application The problem have is how to connect an appropriate action to the new menu items Here s an example that shows how you can change the system menu Make sure to add PlatformWidgetsConstants and the CwConstants pool diction
109. This example assumes that you are setting the background of a form Automatic Tab Moving Questioni How do implement automatic tab moving in a VisualAge text field You can implement auto tabbing in VisualAge by writing some script and making a connection to that script Here is an example Suppose you have two text fields Go into the settings of TextField1 and set its text limit to 5 Then connect the object event make sure it is the event of the text entry field to the following script Smalltalk autoTab position limit position self subpartNamed TextField1 queryCursorPosition limit self subpartNamed TextField1 textLimit position limit ifTrue self subpartNamed TextField2 setFocus Now if the user types five characters in the first text field focus is automatically set to the second text field 132 VisualAge for Smalltalk Handbook Fundamentals Question Is there a way to have it just tab to the next field I have around 10 fields and would rather avoid hard coding all the names USE Use some code such as Smalltalk widget list index next widget self subpartNamed Window framingWidget list widget tabList index list indexOf self subpartNamed field name primaryWidget next list at index 1 next userData setFocus We hooked this to a text field and passed in the self of the text field as the parameter
110. VisualAge for Smalltalk Handbook Fundamentals Answer To me this looks like a dirty solution is there a better way to force classes to be included in the package Implementing the method packagerlncludeClasses on your applications to answer a collection of classes that you want to force the packager to package will solve this problem Browse implementors of packagerlncludeClasses for more details Packaging for AIX from OS 2 Answer We are using VisualAge for Smalltalk for OS 2 V3 0 We need to distribute both OS 2 and AIX clients of the application Can we package the AIX version of the client from our OS 2 development environment Or do we need to export from OS 2 and then import into VisualAge for AIX and then package the AIX version from VisualAge for AIX You must package in the target environment By the way to access a single manager on an AIX machine you can use TCP IP and the EMSRV support for all environments If you do that no import export is necessary just a load and package Loading Application in a Run time Image Answer Is it possible to load APP files into a runtime image not a stock image if the ApplicationLoader and Swapper are included in it It seems that the reduced runtime image AbtEpStandardRuntimeSpecification that comes with VisualAge includes both The reduced runtime image does not have the ApplicationLoader and Swapper applications that you will need to bind APP files to it The
111. Vol2 239 transaction abend Vol2 72 unique key Vol2 46 exit dialog message box 89 Explorer 260 exporting application 245 configuration map 254 pool dictionary 254 extending classes 40 pop up menu 57 F facade class 65 fatal errors 36 318 VisualAge for Smalltalk Handbook Fundamentals fault tolerance Vol2 211 Vol2 220 feature AIX reports Vol2 225 DAT file 253 loading 80 unloading 82 Vol2 223 Vol2 254 field break Vol2 230 calculated Vol2 230 dynamically adding to report Vol2 233 iterator Vol2 226 literal Vol2 109 unprinted Vol2 232 watch Vol2 230 FIFO Vol2 36 file access mode Vol2 46 access part Vol2 4 Vol2 60 agent Vol2 61 AS4RTE20 MRI Vol2 44 blocking factor Vol2 15 broker Vol2 61 closing 208 commitment control Vol2 59 compound key Vol2 28 DDM Vol2 26 direct Vol2 26 existence 177 handle 208 handle limits on UNIX Vol2 224 in use error 43 join Vol2 48 keyed Vol2 26 Vol2 29 Vol2 60 library list Vol2 57 locking Vol2 45 logical record format Vol2 47 macro Vol2 113 member Vol2 11 opening and closing Vol2 43 physical Vol2 11 Vol2 14 read next Vol2 4 read previous Vol2 4 real library Vol2 61 record cache Vol2 19 record description Vol2 31 removing handles 208 sequential Vol2 26 file continued sharing Vol2 24 sharing field names Vol2 47 simultaneous DDM access Vol2 39 system 176 system error 180 unique key Vol2 46 UNIX Vol2 224 file in 28 file out 28 filing out classes 29 fin
112. a problem No Why used a printHex method to look at raw floating point values Expression Result Notes 1 5d0 printHex 1 8000000000000 0 Test case that converts evenly The value is in hex the exponent is hex and is the number of bits to shift the value For the other values it shows Expression Result Notes 1 15 printHex 1 2666666666666 e0 Not exact conversion 45 0 printHex 1 6800000000000e5 Exact conversion Chapter 4 IBM Smalltalk Programming Language 239 Expression Result Notes 10 0 printHex 1 4000000000000e3 Exact conversion Note how 1 15 seems to run forever lt is not represented exactly in binary Now let s look at the results of the calculation Smalltalk 45 0 1 15 10 0 printHex 1 2BFFFFFFFFFFe9 45 0 10 0 1 15 printHex 1 2C0000000000e9 Note how the first expression answers a value just a tiny bit smaller adding a one bit at the rightmost position makes the first equal to the second It s just off the minimum value that a float can be and still be different Such are the hazards of comparing floats for equality The top three rules in using floating point values are 1 Do not compare floats for equality 2 Do not use floats for monetary computations 3 Do not compare floats for equality Immutable Objects and Identity Objects 240 Tip There are two similar terms that are often confused I
113. acting to Keyboard Input 2 o 141 Using Esc to Close Nonmodal Dialog 142 Multiline Edit Part and Tab Order 0 o o 143 Using Predefined Function Keys 0 0 e 143 Grabbing Typed Words o 144 Dropping an Item on a Push Button 2 144 Changing a Part s Settings View 0 0 0 0 0 e 145 Hiding Table Columns Dynamically 145 VisualAge for Smalltalk Handbook Fundamentals Initializing a View Wrapper 0 000002 ee 146 Adding Columns to Tables 2000002000 146 Synchronize Table Scrolling 002000200004 148 Changing Table Size 1 2 a 149 Table List Patt arica as doi eee ea ily sunset of be eS 149 Reusable Table Part 2 02002 e 149 Changing a Table Cell 2 000000 00000504 149 Selecting Multiple Rows 2 0 00 000 pee 150 Changing Push Button Activation 0 150 Event Handling in Windows AIX and OS 2 151 Part Validation 0 Bogie s dabat i e doa g iao a 152 Moving CONS gt ia ae ee ee ee a Qed ot GLA dae tt 152 Printing a Form with a Visual Part 152 Text Box Problem lt r sesa 54568446 demas HH ee eS 153 Reusable Table Part 0 2 0 002 eee eee eee 153 Trap the Enter Key for Tabbing 0 0 e 153 Creating an Operation
114. ains all accessor methods for class variables Creations Contains methods returning one instance of the class Constants Contains constant methods Example Contains methods explaining how to use the class A common usage is showing how to create an instance of the receiver Extensions Used when an extension is made to an existing class of the development tool Initializations Contains initialization methods ResponsibilityName A category name is created for each responsibility for example contract taken by the object Services Contains methods having a general purpose such as boolean or copy methods Tests Contains unit testing methods Chapter 2 General Information 67 Archival Code is Missing Answer had an application on VisualAge for Smalltalk on OS 2 2 11 Now installed VisualAge for Smalltalk on a Warp system and filed in my application and the archive file get all parts but the view wrapper parts are empty the Composition Editor shows only an empty window Has anyone an idea what could be wrong The problem you are experiencing for example no visual parts in any of the windows is usually an indication that the archival code is missing Open a Composition Editor on one of your visual parts and then switch to the Script Editor Check and see if you have any class methods If you generated and then filed in your archival code you should see the following class public methods e calculatelnte
115. al Support Organization Java Database Connectivity local area network logical file megabyte Multipurpose Internet Mail Extensions multiline edit message queueing machine readable information multiple virtual storage national language support new technology Open Database Connectivity object interface definition language on line transaction processing Fundamentals OMT OOP OOSE ORB os os 2 Pcs PM PTF RAM RDBMS RFT RPC RPG SGML SHTTP SOM SQL SSL TCP IP URL VM VMT WWW object modeling technique object oriented programming object oriented software engineering object request broker operating system Operating System 2 PC Support presentation manager program temporary fix random access memory relational database management system request for technology remote procedure call report program generator standard generalized mark up language Secure Hypertext Transfer Protocol system object model structured query language secure sockets layer Transmission Control Protocol Internet Protocol uniform resource locator virtual machine visual modeling technique world wide web Index Numerics 3270 cursor position Vol2 79 host presentation space Vol2 79 A abend transaction Vol2 72 aborting process stack 199 aboutToExecute 207 ABTPATH 213 accelerator keys 157 230 access set Vol2 127 Vol2 145 Vol2 169 accessing
116. al form text Vol2 50 finalization 201 finding mouse pointer location 102 fixed character field Vol2 141 fixed decimal class 182 fixed object space 219 fixes Vol2 9 flat file 247 flips 211 floating point behavior 182 comparing 183 decimal 264 rounding 182 subtracting 183 floating window 98 floating point comparing values 239 focus setting 162 widget 136 folder shared Vol2 4 font scaled Vol2 233 forcing packager 47 forking background process 197 database read Vol2 15 form checker 118 data Vol2 250 printing 152 reusable 140 formatting string 173 FoxPro Vol2 127 fractions 182 freeing up resources 24 function key 143 163 G gadgets icon 107 garbage collection business object Vol2 112 fixed object 219 forcing 174 216 instances 211 object finalization 171 protection 219 rate 174 removing dependents Vol2 33 weak pointer 170 general protection fault 73 generating archival code 246 OLE methods 260 getters and setters generating 54 ghosts 26 GIF on Web page Vol2 250 global variable 172 205 graphical label push buttons 32 graphics priority 209 grid part 20 grouping methods 66 GUI architecture 87 wrapper Vol2 25 H heading hiding 124 headless server Vol2 200 help setting 141 hiding container column 125 heading on container details view 124 notebook page 116 table column 145 visual objects 158 hierarchical break Vol2 235 high level qualifier Vol2 157 Vol2 177 Index 319 HLLAPI
117. al user interface and to make connections among parts concrete class A subclass of an abstract class that is a specialization of the abstract class For example the concrete class OrderedCollection is a subclass of the abstract class Collection configuration 1 A description of a group of components that identifies for each component the component edition or version that is part of the group 2 The arrangement of a computer system or network as defined by the nature number and chief characteristics of its functional units More specifically the term may refer to a hardware configuration or a software configuration 3 The devices and programs that make up a system subsystem or network 284 VisualAge for Smalltalk Handbook Fundamentals configuration file The collective set of definitions that describes a configuration configuration map A named group of application editions A configuration map usually represents a product or one of its major parts connection 1 In VisualAge a formal explicit relationship between parts Connections define the ways in which parts communicate with one another Making connections is the basic technique used for building any VisualAge application See also attribute to script attribute to attribute event to script and event to action connection 2 A linkage between nodes Connections are established and released at the Network Session and Presentation Layers cons
118. alAge for Smalltalk under Windows 95 or Windows NT Removing Elements from a View Question How do remove elements from a tree view We opened APAR PN82758 on a problem that sounds very similar to this problem Here is a workaround or fix In EwHierarchy gt refreshltems childrenBlock Change the lines that read Smalltalk oldExpandedltems add self items at index oldExpandedNodes add node To the following Smalltalk index between 1 and self items size ifTrue oldExpandedltems add self items at index oldExpandedNodes add node Class EmLibraryStatistics Question Where is the class EmLibraryStatistics that was in IBM Library Tools configuration map It was left out of the Version 3 0a refresh manager You can import the configuration map from your Version 3 0 manager into your Version 3 0a manager The code hasn t changed between the two Chapter 2 General Information 71 Error rc 12 Questioni What does a rc 12 for abt exe mean Try executing the following code Smalltalk Object primitiveErrorStringFor 12 gt Not enough memory Error SYS317x Questioni Can avoid SYS317x in ESVM30 DLL PMMERGE DLL or xxx DLL on OS 2 OTI believes that many of the SYS317x messages our customers are seeing are due to stack overflow When the stack overflows some reasonably important data is trashed in ABT EXE The effect of trashing this data can be immediate or delayed d
119. alk ANSI officially approved the IBM project proposal for Smalltalk The project name is X3 Project 986 D and the technical committee is X3J20 Smalltalk Portability A Common Base document number GG24 3903 contains the proposed ANSI standard 166 visualAge for Smalltalk Handbook Fundamentals Construct Questioni What does do The construct in IBM Smalltalk is not unlike define from the C world It allows you to have objects created at compile time rather than at run time We all use 1 2 3 to create an array at compile time Well is no different It just lets you create objects other than arrays Writing Smalltalk expression evaluates the expression at compile time as if it were text selected in a workspace but takes the resulting object and places a reference to it in place of the construct Thus Smalltalk x 60 60 24 would return the number of seconds in a day The expression is evaluated at compile time At run time it acts as if this had been the source code Smalltalk x 86400 Now it is possible that the compiler could make this optimization But how about this Smalltalk birthdays birthdays Dictionary new birthdays at Boris put Jan 05 birthdays at Dennis put Jul 05 birthdays at Leo put Jan 05 birthdays The dictionary is created at compile time and not every time one ru
120. alk Organizer dialog Chapter 7 National Language Support 267 268 VisualAge for Smalltalk Handbook Fundamentals Appendix A Special Notices This publication is intended to help VisualAge for Smalltalk developers avoid common programming pitfalls and as a guide for frequently asked questions about the IBM Smalltalk language VisualAge for Smalltalk and its features The information in this publication is not intended as the specification of any programming interfaces that are provided by VisualAge for Smalltalk See the PUBLICATIONS section of the IBM Programming Announcement for VisualAge for Smalltalk for more information about what publications are considered to be product documentation References in this publication to IBM products programs or services do not imply that IBM intends to make these available in all countries in which IBM operates Any reference to an IBM product program or service is not intended to state or imply that only IBM s product program or service may be used Any functionally equivalent program that does not infringe any of IBM s intellectual property rights may be used instead of the IBM product program or service Information in this book was developed in conjunction with use of the equipment specified and is limited in application to those specific hardware and software products and levels IBM may have patents or pending patent applications covering subject matter in this document The fu
121. alled every time the user clicks on the slider bar down arrow The callback method will have to scroll the second table down one row To synchronizing scrolling between two tables you would need to add callbacks for each type of scroll request In addition you would need to add them for both CwScrollBar widgets 148 VisualAge for Smalltalk Handbook Fundamentals Changing Table Size Answer How do create a table that can grow and shrink in size Create an example of what you want save that part then look at the abtBuildinternals method lt shows the code that constructed the part You can copy or modify it to dynamically add parts A common mistake is to forget to send openWidget to the newly added part including container detail columns it is necessary if the view is already open Table List Part Answer Is there a table list part that has capabilities like row selection and programmatic column setting EwTableListExample fullfills these requirements EwTableList is the CommonWidget class used by the Container Details View available on the parts palette Reusable Table Part Answer How do create a reusable table part You should promote the width attribute of each column so it becomes an attribute of the reusable part They should be able to change the width through the settings of the reusable part or via a script The width cannot be changed with the mouse because embedded parts are treated as sing
122. an integer This integer can be incremented and converted to a different character if it is not too big In neither case is the immutable object changed internally the result is always a new value and all variables that hold the original value still hold it 242 VisualAge for Smalltalk Handbook Fundamentals Chapter 5 ENVY In this chapter we cover the ENVY programming environment Working with the Team Environment Answer We expect to have to put in quite a number of hours on our VisualAge for Smalltalk project on a tight schedule We are running in the Team environment at the office We would also like to do some development at home We have access to our Team server library drive remotely via LAN Distance and Netware Rather than have to go through all that is required to export the application or its parts we d like to simply have a client environment at home as well as at work The license agreement seems to allow this so from a technical point of view how should we set up the environment Are there any issues with respect to synchronizing the home client image with that at the office Do we need to make our image consistent or recache the pointers Principally speaking do not see how your home setup differs from your office setup Basically you share the same library across your remote LAN extension Since nothing is really locked in the library there should be no problem loading your editions at home
123. anager to handle this or run this script using aDateString as an example when losing focus Smalltalk AbtDateConverter new primDisplayToObject aDateString ifError error CwAppContext default asyncExecInUl aView setFocus Moving Icons Questioni How do move icons around in a window If the icons were drawn as a label widget you would use CwWidget gt gt makeGeometryRequest replyReturn if the label is an attached widget otherwise CwWidget gt gt moveWidget y see the comments of these methods for more details Moving a widget to simulate a spinning effect for example probably wouldn t look very smooth ld probably go directly to the Cg layer using a variation of the code in the CgClock examples for drawing the wheel points and perhaps CgStix for animating the spinning of the arrow Printing a Form with a Visual Part 152 Questioni How do print a form created that contains a visual part You create a CwPrinterShell initialize the shell on the map callback and draw your text during the expose callback The printer shell has additional APIs to support job and page start and end You can set fonts and colors by modifying the attributes of the graphics context GC for the printer shell CwTextPrintingManager uses CommonPrinting to print workspaces you can see the basics there VisualAge for Smalltalk Handbook Fundamentals Text Box Problem Question have a problem using the default
124. and enhance applications replaceable You can update an IC with bug fixes or patches and replace the existing IC not the entire image file Provided the Smalltalk code in an IC is platform independent an IC is portable because the same IC file will load and execute on all platforms supported by VisualAge for Smalltalk Version 4 0 Smalltalk Language and Tool Enhancements Support for ICs is just one of several improvements that have been made to the Smalltalk language and tools in Version 4 0 Breakpoints have been added to the debugger enabling you to more easily find isolate and remove bugs from your code You can set a breakpoint on any line of Smalltalk code and you will see a red dot in the margin of the browser indicating that a breakpoint is set The executing program stops when the breakpoint is reached and you can begin debugging at that point by stepping through the code inspecting objects and so forth A conditional expression can be associated with a breakpoint and the execution will stop only when the condition is true Thus you can isolate those hard to find bugs that occur when the state or content of an object becomes incorrect by setting a breakpoint that will only trip when that occurs You can also set the number of iterations a breakpoint must be reached before the execution will be stopped so that you can debug pieces of code that are executed repeatedly without stepping through each iteration manually From the devel
125. archical file system a piece of related information data such as a document 3 In SQL the term is generally referred to as a table file in A Smalltalk command for compiling external definitions of applications classes and methods from a text file file name 1 A name assigned to or declared for a file 2 The name used by a program to identify a file file out A Smalltalk command for writing definitions of applications classes and methods to an external text file firewall A combination of hardware and software that protects a local area network LAN from Internet hackers It separates the network into two or more parts and restricts outsiders to the area outside the firewall Private or sensitive information is kept inside the firewall first in first out FIFO A queuing technique in which the next request to be processed from a queue is the request of the highest priority that has been on the queue for the longest time fixed length record A record having the same length as all other records with which it is logically or physically associated 288 VisualAge for Smalltalk Handbook Fundamentals form An HTML element that can include entry fields push buttons and other user interface controls through which users can enter information Sometimes called a fill in form format 1 A specified arrangement of such things as characters fields and lines usually used for displays printouts or files
126. are running try this Smalltalk System configuredSubsystems This will answer a LookupTable which on OS 2 may contain something like this ABT VA ABTVER V 3 0b CFS 08 2 CG PM Chapter 4 IBM Smalltalk Programming Language 199 CLDT ES CLIM ES CP PM CPM ES CW PM Image Copyright Answer How do go about getting the image copyright programmatically You can get a string with the image copyright programmaticaly through executing Smalltalk System copyright Command Line Arguments Answer Do I have access to the command line arguments If you want the Smalltalk equivalent of the C variables argc and argv send the following Smalltalk System commandLine This will return you an array of strings including the executable name at index 1 Run Time Image How do I find out whether the the current image is a run time image 200 VisualAge for Smalltalk Handbook Fundamentals IBM Smalltalk has its own notion of whether the running image is a run time image You can get this information by sending Smalltalk System isRuntime EsWeakSet and Finalization Questioni How do go about synchronizing an EsWeakSet with the real state of objects EsWeakSet and finalization do work together that is finalization keeps a weak set of objects that could po
127. arget application and class The following methods are archival e Public Class Method calculatelnterfaceSpec calculatePartBuilder e Private Class Methods add PartBuilder codeGenerationParameters connect converter PartBuilder test Chapter 2 General Information 37 Apply Push Button Answer Inspector Answer Multimedia Answer There are unlisted actions for both an okay and cancel push button on a part s custom settings view but how do you handle an apply push button If you are creating a VisualAge part and want the custom settings view to have an apply push button add an event to script connection from the push button clicked event to the following script Smalltalk apply op newOp op self subpartNamed updateOperation value execute newOp op target customSettingsOperation stackHolder op stackHolder defaultValuesSource op defaultValuesSource target op target self subpartNamed updateOperation value newOp How can quickly open an inspector on a part in the Composition Editor Do Alt Shift Click1 on a part in the Composition Editor Where do find examples of using multimedia in VisualAge There are multimedia applications on the VisualAge CD Also when you load the Multimedia and Multimedia Samples features you will get an application named AbtMultimediaSamplesApp in your Organizer window In this applicati
128. ary to your class definition first Note that the second parameter of hook with is the method that will run when the menu item is selected and it must take one parameter even though you do nothing with it The example also highlights the use of an accelerator key Chapter 2 General Information 41 Smalltalk menultem key osWidget systemMenu owner self yourself ifAbsent nil menultem alt true shift false control false virtual true key key createMenultem menultem label my item accelText Alt F2 hook OSxSelect with myAction key VkToKeySym keyAtValue XKF2 menultem self subpartNamed Window1 yourself primaryWidget Organizer Views 42 Tip You can switch to different views in the Organizer For example it can look like this EE AbibxamplesHelpApp Y 3 0a CELI a BorisSpliterApp 1 11 II VisualAge for Smalltalk Handbook ApiExamplesHelp rchivedApp V 3 Da Fundamentals ooDialogManager AcocDialag AoDialogApp AxxDialogContral oxDialogFushGutton AxxDialogstatic AoDialogTestyiew oxDialogTextE ntry JxxDialagAppAbtPackage Smalltalk class Smalltalk class Smalltalk class Smalltelk class Smalltalk class Smalltalk class Smalltalk class visual part Smalltalk class File in Use Answer What might cause a Fi
129. as been user input Beep DosBeep callWith 100 with 200 Caret Shape Cursor Question have some text entry fields where the cursor is positioned at the right edge If tab into these empty fields nearly cannot detect in which field the focus is actually set because of the look of the cursor which is a thin line How can define another caret look for entry fields You can t change the caret look for your entry field The entry field input cursor known also as the caret I bar is defined by the operating system and cannot be changed by an application Some operating systems have configuration options to change the mouse cursor resize cursor and the text input cursor If you want a VisualAge for Smalltalk solution you could connect the gettingFocus and losingFocus event to a label s show and hide actions Put the label next to the entry field as Address i The asterisk will show when the field has the focus and hide when it doesn t Mouse Pointer Location Questioni How can find the position of the mouse cursor on the screen You can detect the cursor location in one of two ways You can call the OSWidget class method widgetUnderCursor to see where the cursor is or you can add a Pointer Motion Mask event handler to find where the cursor is and see if it s in the desired area see page 192 of the IBM Smalltalk Programmer s Reference for an example of the latter You can change the font of a cursor by
130. ase driver supported by ODBC the capability always exists within VisualAge to drop into the Smalltalk development environment to build any type of unique class library and parts you need Communication Protocol Support 8 Answer Which communications protocols does VisualAge for Smalltalk support Communications protocols are supplied in the VisualAge for Smalltalk Communications Transactions feature and include TCP IP APPC CPI C NetBIOS CICS ECI EHLLAPI MQSeries and RPC VisualAge for Smalltalk Handbook Fundamentals Legacy Code Answer Runtime Dist Answer How does VisualAge for Smalltalk handle legacy code You can wrapper legacy COBOL C or C applications into parts by using the COBOL C and C support included with the base product The IMS Connection feature enables you to wrap existing IMS transactions to be used as parts within the VisualAge for Smalltalk environment IBM SOM and DSOM support enables you to reuse existing SOM and DSOM objects as VisualAge for Smalltalk parts ribution Fees Are there any run time distribution fees for VisualAge or IBM Smalltalk No In contrast to many contemporary application development tools the VisualAge and IBM Smalltalk license agreements allow you to freely distribute the run time environment for the applications you write with VisualAge Distributing Smalltalk Compiler Answer Can the Smalltalk compiler be distributed with a run time applic
131. ass gt gt cwWidgetClass You could map the Esc key or any key you prefer yourself to close Here s an example First connect the Window part s openedWidget event to a script Smalltalk hookKeyReleaseEvent self subpartNamed Window components do view view primaryWidget addEventHandler KeyReleaseMask receiver self selector keyReleased clientData callData clientData nil VisualAge for Smalltalk Handbook Fundamentals This puts a key release hook on every widget under Window Next add a method to handle the key release Smalltalk keyReleased w clientData d callData callData callData keysym XKCancel ifTrue self closeWidgetCommand Note XKCancel is the Motif name for the Esc key Multiline Edit Part and Tab Order Answer If drop a multiline edit part on a window can t use the tab key to navigate through the different objects on the window The multiline edit part uses the tab key for spacing Is there another way to navigate through the window You can use Ctrl Tab instead to navigate through the different objects on a window Using Predefined Function Keys Why does the following code not work to catch the event when pressing a function key The code adds an eventHandler to the widget of the part and should cause a debugger window to come up as soon as an function key is pressed Smalltalk widget widget self subpartNamed myF
132. at provides the default behavior of closing when the Esc key is pressed and this is operating system behavior not part of VisualAge The solution above hooks to the system close action Since you are bringing up a dialog the Esc key is mapped to close by the CwDialogShell class for details see AbtShellView class gt gt cwModalWidgetClass and AbtShellView gt gt primCreateWidget If you do not set an owner window the CwTopLevelShell is used as the shell class see AbtShellView class gt gt cwWidgetClass You could map the Esc key or any key you prefer to close Here s an example First connect the Window part s openedWidget event to a script Smalltalk hookKeyReleaseEvent self subpartNamed Window components do view view primaryWidget addEventHandler KeyReleaseMask receiver self selector keyReleased clientData callData clientData nil This puts a key release hook on every widget under Window Next adda method to handle the key release 134 VisualAge for Smalltalk Handbook Fundamentals Smalltalk keyReleased w clientData d callData callData callData keysym XKCancel ifTrue self closeWidgetCommand Note XKCancel is the Motif name for the Esc key Transparent Background Questioni How can make the background of some text placed on top of a bitmap be transparent CwLabels cannot be made transparent suggest you hook the expose callback of the form and draw the t
133. atform to Windows NT or 95 the notebook is replaced by a VisualAge icon Why The OS 2 Windows notebook is not available on Windows NT or 95 since it is built from a 16 bit class library However you can migrate the notebook to the portable notebook which is supported under all VisualAge platforms by selecting Morph from the pop up menu of the icon that you are seeing This will morph the OS 2 notebook to the portable notebook Navigating between Columns Questioni How do I navigate between columns in a container without using the mouse Use CELLSINGLESELECT selection technique Selecting Valid Items Question l am using a container details part There are some rows that cannot be selected by the user depending on the data in the object whereas other rows may be selected Is there some kind of callback can capture that would allow me to deselect a row when do not want the object to be valid The container details will signal a selectedltemsChanged event every time the user modifies the selection You can then examine the selected items and change the selection to include only the valid objects using selectedltems Be careful of getting stuck in a loop some parts will resignal selectedltemsChanged even if the new selection is the same as the previous one You may have to keep track of this yourself Chapter 3 Graphical User Interface 117 Validating Input Fields 118 Question We have a written a notebook applic
134. ation No Redistribution of the Smalltalk compiler is not permitted The compiler is a key component of the VisualAge application development environment itself You must purchase one license for each compiler distributed However you can distribute the run time without a fee Source Code Answer Availability How much of the Smalltalk source is available with the VisualAge for Smalltalk product 99 of the source code is available Some methods remain proprietary and are still hidden however those methods are typically code that is not required for application evelopment for example method code in the Smalltalk compiler Chapter 1 What Is VisualAge for Smalltalk 9 Upward Compatibility Answer Is an application written for one version of VisualAge for Smalltalk compatible with the environment of a higher version of the product One of the features of the IBM VisualAge development environment is the ability to easily port existing VisualAge applications to other platforms and to easily upgrade the run time environment for a new release of VisualAge All you have to do is repackage the application with the new run times and DLLs Common User Access Compliance Answer Does VisualAge for Smalltalk force Common User Access CUA compliance CUA compliance is up to the programmer However with VisualAge it is a simple task to produce fully CUA compliant applications Multiple Inheritance Questioni Does
135. ation where data needs to be entered on different pages After the data has been entered need to see wether it is valid The following problem occurs when the user skips to the next or previous page A prompter might pop up on the new page displaying a message that shows the validation error from the previous page What can we do to prevent this from happening answer ER 1 2 3 4 5 6 7 solve the problem it sounds like a good idea to use a form checker Drop a form checker part onto the free form surface Following the example on page 149 in the VisualAge for Smalltalk User s Guide connect the verificationRoot attribute of the form checker part to the self attribute of each notebook page you want to verify Add an instance variable called lasiPageSelected to your visual part class Connect the switchedToMe event for each page to the following script Smalltalk saveLastPage Save the current page as the last page selected before the page is turned self lastPageSelected self subpartNamed OS 2 Windows Notebook topPagelndex Connect switchFromMe to the check action of the form checker part Create a script called keepPageOnTop as follows Smalltalk keepPageOnTop Keep the last page selected on top of the notebook by switching to it self subpartNamed OS 2 Windows Notebook topPagelndex self lastPageSelected In the set method for lastPageSelecte
136. ative words in a title or document that describes the content of that document Glossary 291 3 A name or symbol that identifies a parameter 4 A part of a command operand that consists of a specific character string such as DSNAME keyword message A message that takes one or more arguments A keyword is an identifier followed by a colon Each keyword requires one argument and the order of the keywords is important hello at 2 put H is an example of a keyword message at and put are keyword selectors 2 and H are the arguments See also message kilobyte A thousand bytes Actually usually 1024 210 bytes See also byte bit L LAN See local area network library 1 A shared repository represented by a single file lt stores source code object compiled code and persistent objects including editions versions and releases of software components 2 A system object that serves as a directory to other objects A library groups related objects and allows the user to find objects by name To identify a specific object to the system a user needs only to provide the object name the object type and the name of the library containing the object link 1 The logical connection between nodes including the end to end link control procedures 2 The combination of physical media protocols and programming that connects devices on a network 3 In computer programming the part of a program in s
137. attributes That is assume you have the object RightAngleTriangle with attributes a b and c where c is calculated based on a and b Using a deferred update part you will never see attribute c calculated until the user hits the apply button whereas without the deferred update part the attribute c will be updated as either a or b changes Second if you allow your users to open different views on the same object they may have made some changes on a view and not applied them When they then open a second view on this object it comes up without the changes they have just made on the first view and things look inconsistent In my opinion you have a couple of strategies depending on your application but the best is to have the view ask for a copy of the object this may even be a specific copy for this view Have the view be a view of the real objects and then you get all the behavior right away that the object should exhibit If the user cancels it is the view s responsiblity to set the object back into its original state VisualAge for Smalltalk Handbook Fundamentals Opinion Two To the naked eye the deferred update parts can be of little use once your objects consist of a bit more than primitive attributes But believe it or not we found ways around the problem You just have to look closely at the AbtDeferredUpdatedManager and what it does Your domain object can implement two different class methods which the Manager sends
138. can be run to determine the cat and mpr message files that are needed by an IC image at run time It will show a list of all IC packaging instructions that are currently loaded When you select a packaging instruction the required run time message files will be listed on the Transcript VisualAge for Smalltalk Handbook Fundamentals Smalltalk appCollection catFiles mprFiles instructionNames instructionName instructionClass work instructionNames EpAbstractPackagingInstructions withAllSubclasses collect ea ea name asSitring asSortedCollection asArray instructionName CwListPrompter new title Find cat and mpr files required by the selected IC items instructionNames prompt instructionName size O ifTrue self instructionClass Smalltalk classAt instructionName ifAbsent self appCollection Set new catFiles Set new mprFiles Set new instructionClass actuallncludedSubApplicationNames do eachApp appCollection add eachApp asClass rootApplication J instructionClass prerequisitelCs do eachICInstructionClass eachICInstructionClass asClass actuallncludedSubApplicationNames do eachApp appCollection add eachApp asClass rootApplication appCollection do eachApp poolINames mprName poolNames eachApp definedPoolNames poolNames do eachPoolName pool catName pool Smalltalk at eachPoolName ifAbsent eplsPoolDictionary ifTrue catName
139. ce an archival application for each one of your applications Remember If you want to share code you will have to file out both applications the original and the archival Deleting Parts with Instances Question How do I delete a class or part that still has instances USES To remove instances of a class execute Smalltalk lt MyClass gt alllnstances do anlnstance anlnstance become nil Although this method of removing instances does work and all of us have resorted to it at some time or another we should warn you that it is dangerous You will usually get away with this but it can also cause walkbacks and even system crashes or meltdowns Use it at your own risk Chapter 2 General Information 35 Change Table Format Questioni How can change the dashes on a table to a line You can use the following code Smalltalk setGridLineStyleAndColor Set the line style and color appropriate for the grid self foreground self clrGrid lineStyle AbtTWLineStyleGrid ifTrue self already done self gc setLineAttributes 1 line width lineStyle self useDashedLines ifTrue LineOnOffDash ifFalse LineSolid capStyle CapButt joinStyle JoinMiter lineStyle AbtTWLineStyleGrid The table defaults to having solid lines To change the table to have dashed lines true needs to be sent to the useDashedLines method This can be accomplished by conne
140. ch the signaled event name To fix this change the OlexPropertyDescription gt gt abtSetSelectorWithlnterace method Change the code lines Smalltalk nextPutAll self signalEvent nextPutAll selectorName asSymbol printString Smalltalk nextPutAll self signalEvent nextPutAll selectorName Changed asSymbol printString Free Disk Space on Windows Platform Questioni Does anybody know how to retrieve free disk space information on Windows platforms The GetDiskFreeSpace function call returns the following information 1 Number of sectors per cluster 2 Number of bytes per sector 3 Number of free clusters on the disk 4 Total number of clsuters on the disk Pointers to variables where the above information can be returned must be passed to the GetDiskFreeSpace function To get the total amount of free disk space you must multiply the sectors per cluster by the bytes per sector by the number of free clusters Listed below is code that will call the GetDiskFreeSpace function calculate the amount of free space on C and display that value in a message prompter Chapter 6 Microsoft Windows 261 Smalltalk oscall freeSpace sectorsPerCluster bytesPerSector freeClusters totalClusters rc oscall OSCall new sectorsPerCluster ByteArray new 4 bytesPerSector ByteArray new 4 freeClusters ByteArray new 4 totalClusters ByteArray new 4 rc oscall getD
141. ck tabbing in details views 74 background process continuing 201 database update Vol2 155 task garbage collection 174 background transparent 135 beep 101 bibliography 271 Vol2 259 bind command syntax Vol2 117 bitmap click sensitive 140 color 131 colors 139 image formats 140 on notebook tab 115 push button 161 resolution 131 bitmap on button 136 block creating at run time 192 reading from file 192 blocking factor Vol2 15 Vol2 19 broker file Vol2 61 registry Vol2 33 browser DBCS part name Vol2 255 progress message 156 suppressing URL query string Vol2 253 BRW format generator 43 building visual forms Vol2 3 business class 208 object garbage collection Vol2 112 key alteration Vol2 112 busy cursor 100 105 button activation 150 bitmap 136 161 disabling 106 156 Vol2 249 dynamic 160 enabling 150 mask 159 toggle 105 C C Vol2 89 Vol2 91 Vol2 96 Vol2 103 CA 400 ODBC Vol2 5 Vol2 42 Index 309 cache 50 Vol2 19 caching compiler CAE vol2 5 calculated field Vol2 230 call stack trace 21 192 call level interface Vol2 120 callback CICS ECI vol2 104 losing focus 56 mouse move 157 synchronizing table scrolling 148 calling convention Vol2 95 Vol2 101 OSObjects Vol2 95 capturing key pressed events 230 stack information 28 caret cursor 102 carriage return missing 162 CAT files 50 264 Vol2 251 catalog of classes Vol2 230 catching all errors 181 errors 179 category class meth
142. comment it s not stored in the image One day when have some spare time lIl write a program to automate this testing though my experience is that there are frequently insignificant changes to the output that would frustrate the automation I can see the difference is minor the test program would not As an aside a crucial requirements for such testing to work is to code a decent printOn method in every new class which prints enough details to identify the result Merely relying on Object s default a NewClass makes testing very hard You can always use a naming convention One that s possible in Digitalk Smalltalk and perhaps elsewhere is to use a capital letter in the method name Digitalk creates Doit methods all over the place for example Test or Testinteraction It s not to hard to strip such methods from the image With Visualage for Smalltalk you should be able to extend your class in a separate test application to hold all the instance class test methods for your class Garbage Collection Rate 174 Answer Can a Smalltalk application accessing many data objects in a short time from a large relational database via a persistence layer cause the workstation to page or swap excessively because the rate of object creation exceeds the rate of garbage collection The only way to determine this is to try When and if garbage collection runs differs from product to product release to release If you are
143. correctly translated to the new code page For example on my machine on Windows character 252 U umlaut On OS 2 that same character is 129 However don t have to modify the MPR file generated on Windows because code points are automatically translated for text stored in MPR files The ABTRULES NLS file contains the mappings and AbtCharacterTranslator handles the translations All you have to do is this 1 Generate your external strings with YourApp abtGenerateExternalStringsl Necessary 2 Add abiExternalizedStringBuildinginfo method to your application 3 Add loaded method that calls self abtRegisterExternalStrings O Copyright IBM Corp 1997 263 4 Add unloaded method that calls self abtUnregisterExternalStrings Required CAT Files Tip The following script helps you to determine based on your packager output log which CAT files you need with your run time image Just save the output log to a file and then run this script Smalltalk stream tokens file file CwFileSelectionPrompter new title Packaging Messages prompt file isNil ifTrue Snil stream CfsReadFileStream open file stream atEnd whileFalse tokens stream nextLine subStrings tokens size gt 0 and tokens at 1 indexOfSubCollection NlsCat startingAt 1 gt 0 ifTrue Transcript cr show References messages in Smalltalk at tokens at 1 asGlobalKey at CATALOGNAME
144. cting the aboutToOpenWidget event of the table to a script connection with similar code Smalltalk dashedLines self subpartNamed Table useDashedLines true Error Messages Questioni How do find information on fatal errors 36 VisualAge for Smalltalk Handbook Fundamentals Answer From the System Transcript display the following code Smalltalk SystemPrimitiveErrors keyAtValue errorNumber Example SystemPrimitiveErrors keyAtValue 33 If you highlight this code and choose Display the following is returned PrimErrlmageFileOpenError Removing Archival Code Answer How do remove archival code from my base application if generated it here instead of to an archival application Generating archival code to a new application will not move methods to the new application if they have previously been generated to a different application This is important especially when packaging your application to an image You should not package archival code to a run time image You may either delete the methods below from all classes in your application or move them to the new archival application If you delete them be sure to generate archival code to your new archival application after deletion To move the archival methods select the Move methods choice from the Classes pull down menu of an Application Browser or Classes Browser When prompted where to move the method type the name of the t
145. ctor abtAsInteger freeClusters abtAsInteger CwMessagePrompter message Free space on disk C is freeSpace printString Using LookupTable Instead of Dictionary Tip just did some timings of LookupTable and Dictionary LookupTable is faster typically about 15 to 20 but the difference is greatly influenced sometimes dwarfed by the selection of the key class The table below shows the test code run with both Dictionary and LookupTable and four kinds of keys In each case a random number between 0 0 and 1 0 is selected The number is used sometimes after is is transformed as a key Strings Floats Nice Ints Bad Ints 0 1 1 1000 1 huge Dictionary 136 22500 60 61 LookupTable 120 18600 50 51 The keys are formed like this 234 VisualAge for Smalltalk Handbook Fundamentals Strings A printString of the random number Floats The raw random number in the 0 0 1 0 range Nice Ints An integer in the 1 1000 range 1000 is the collection size Bad Ints An integer in the 1 7654000 range arbitrary range Here are some observations Integers happen to be extra nice keys because they are their own hashes and seem to distribute well over the dictionary and table size Strings hash quickly to a nice integer Floats hash by truncating to an integer and answering that integer That is always zero for the selected keys A fact didn t know until tried to explain the awful resul
146. d be sure to add a catch for the special case when the notebook is first opened and the index is 0 instead of 1 VisualAge for Smalltalk Handbook Fundamentals Smalltalk lastPageSelected anlnteger realPage realPage anlnteger 0 ifTrue 1 ifFalse anlnteger lastPageSelected realPage 8 Connect the checkFailed event of the form checker part to the keepPageOnTop script Also connect that same event to the showErrorToUser action Container Column List Box Question How do I create a container details column that displays a drop down list box for each item Take a look at AbtContainerTreeChildrenAttributesPage and the methods initializeHasChildrenAttributeList and initializeChildrenAttributeList Also take a look at EwEditPolicy Another good place to look for examples is the EwExampleLauncher and CwExampleLauncher You can load these by selecting the Smalltalk programmning examples from the Load Features menu option EwExampleLauncher is the one that you want to examine Type EwExampleLauncher new open select the code and execute it to bring up the example launcher think the EwxTableListExample contains exactly what you are looking for and the Abt stuff listed above will help you incorporate the code into the AbtLayer EwxEditPolicy also contains similar examples Columns with GUI Elements Question Can I create columns that contain GUI elements in particular check boxes so that the user can
147. d library access using the Microsoft Client for Netware Networks and has found problems that may result in corrupt libraries if this requestor is used The problem has been logged with Microsoft Australia Technical Support as Problem 1570370 Chapter 5 ENVY 257 258 The Client32 for Windows 95 requestor must be used only in conjunction with two patches available from Novell e c3295c exe Client32 for Windows 95 Update C e landr5 exe server patch If these two patches are not used users may experience severe performance problems when reading from attached servers and may also find that locks are not correctly released if more than one image is running concurrently on the same machine The two patches will correct both of these problems The Client32 for Windows 95 requestor has many parameters that may be changed in the Advanced Settings dialog IBM has tested with default settings provided on installation which in most cases trade data integrity for performance for example True Commit set to off Although other settings have not been tested changing any of the settings in the Performance Cache parameter group to less optimistic values should not present any problems ENVY Manager s release lock mode parameter should be set to true when using this configuration VisualAge for Smalltalk Handbook Fundamentals Chapter 6 Microsoft Windows In this chapter we cover VisualAge for Smalltalk on the Microsoft Window
148. date progress indicator gt occasionally 4 Background process finishes calls CwAppContext default syncExecInUl lt close process indicator gt Sometimes developers forget step 2 and run off the user interface process It doesn t halt VisualAge because the database component forks work processes but they don t get user interface updates as they expect Alternative approaches to background processing are covered in the BM Smalltalk Programmer s Reference Chapter 4 IBM Smalltalk Programming Language 197 Pool Dictionary Answer How do define a pool dictionary A pool dictionary is simply a dictionary that is used to declare constants You can define it with Smalltalk Smalltalk at YourPoolDictionaryName put Dictionary new or Smalltalk Smalltalk declarePoolDictionary YourPoolDictionaryName Swapper Error Answer Why do I get an error message when loading variable references It says swapper error Sounds like what you ve dumped has a reference possibly a subclass of extension to or contains a class variable instance of a class that was reduced away in the run time image you are binding to Was the run time image you are binding to created by the packager as a reduced image If so you must pay careful attention to both what actually exists in that image and what the application files you create require to ensure that the application file does not refer to nonexistent cla
149. dentity and Immutable Here is a definition of both Identity object An object where each object with the same value is the same object Identity objects include characters small integers true false nil and symbols The reason why each of these objetcs is an identity object differs but the result is the same If a and b refer to identity objects and a b is true then a b is always true as well Thus 2 2 1 3 is always true Immutable object An object whose contents are never modified Instead of modifying the contents a new object is answered VisualAge for Smalltalk Handbook Fundamentals Two objects with the same value are different objects 2 0 2 0 produces a 4 0 that is different from the 4 0 produced by 1 0 3 0 both have the same value but are not the same object Immutable objects include large integers floats and anything else you happen to code to be immutable If a and b refer to immutable objects and a b is true then a b may or may not be true as well Identity objects and immutable objects are not opposite terms In fact all identity objects are immutable objects Here is some related information Mutable objects Mutable objects have internal states that can be changed Most objects are mutable including most of the objects people typically write Points for example are mutable One can write p x p x 1 to increment the x value The result is stored in the same instance of point No
150. distributed transaction processing and remote database access A transaction program TP using the APPC API can communicate with other TPs on systems that support APPC 2 An implementation of the Systems Network Architecture SNA logical unit LU 6 2 protocol that enables interconnected systems to communicate and share the processing of programs agent A VisualAge part used to encapsulate business logic and data access executed outside a VisualAge for Smalltalk image allocate A logical unit LU 6 2 application program interface API verb used to assign a session to a conversation for the conversation s use Contrast with deallocate American National Standard Code for Information Interchange ASCII The standard code using a coded character set consisting of 7 bit coded characters 8 bits including parity check used for information interchange among 279 data processing systems data communication systems and associated equipment The ASCII set consists of control characters and graphics characters analog Pertaining to data consisting of continuously variable physical quantities Contrast with digital anonymous FTP Using the FTP function of the Internet anonymously by not logging in with an actual secret login ID and password Often permitted by large host computers that are willing to share openly some of the files on their system to outside users who otherwise would not be able to log in See also FTP
151. do get a hold of the signature Class gt gt method for the sender of a method In other words during the execution of a method how can find out who sent me To get the sending method just send Smalltalk Processor activeProcess methodAtFrame 1 This will answer the CompiledMethod who sent the method currently executing It can be extremely instructive to have a look at EslmageStarUp class gt gt outputWalkback on process Chapter 4 IBM Smalltalk Programming Language 195 The debugger itself provides a good clue to information like this but note that much of this code is development time only and private That said take a look at Process gt gt receiverAtFrame Process gt gt stackAtFrame offset good comments in this method View the senders of stackAtFrame offset for lots of examples of how to use it Sender Context Questioni How do I find the sender context of a method E You can use Smalltalk Process gt gt contextAtFrame frameDepth The following script prints out the top ten stack frames Smalltalk level nFrames level 10 nFrames Processor activeProcess numberOfFrames 1 1 to level min nFrames do fl Transcript cr show Processor activeProcess methodAtFrame f printString show to show Processor activeProcess receiverAtFrame f printString 196 VisualAge for Smalltalk Handbook Fundamentals Pool Dictionary Tips Ans
152. does the run time image get updated as the user exits the application You cannot normally update a run time image In order to do save changes you have to choose other techniques for example external files using the CfsFileStream class Chapter 4 IBM Smalltalk Programming Language 205 Class Methods at Run Time Answer Is there a way to check if a method exists in a class at run time something like allMethodsNamed selector The following code returns true if my class or a superclass contains a method implementation for the message selector and false otherwise Smalltalk myClass respondsTo myMethod ifTrue method exists ifFalse method doesn t exist Objects s Knowledge of Reference Answer Review the following code Smalltalk a b a SomeClass new b t a When variable b is assigned the value pointed to by variable a does the object that variable a is pointing to have any knowledge that it is being passed around there a way to inform the object when it is referenced The variable b not the object b is assigned the value pointed to by the variable a There are no messages sent and no code is triggered One approach to solve this problem is to put a wrapper around the object and let others pass the wrapper around Your class would look something like this 206 VisualAge for Smalltalk Handbook Fundamentals Smalltalk SomeClass class gt gt new
153. e What does it do actually First of all it clears out the dependents dictionaries Then it terminates all the running processes except the currently activeProcess lt then resets the Organizer applications view and restarts it And finally it does CommonWidgets reinitialize Chapter 2 General Information 25 Ghosts Answer How do get rid of unwanted ghosts multiple instances of my parts hanging around don t know what you are doing to cause them to hang around do you save your view instances in a global or class variable but you can scrub VisualAge with Smalltalk System abtScrublmage It clears out the dependents dictionaries and a few other things that can get messed up after lots of walkbacks Look at EmSystemConfiguration gt gt abtPrimScrublmage for details If you still have instances after running the scrub check who is referencing them with allReferences In addition make sure that if you are closing your views programatically you are sending closeWidgetCommand and not close Widget Image Growth after Packaging would bet that your image size has grown as the result of saving your image after doing the packaging I ve noticed that something created by the packager gets a global reference and is therefore never garbage collected To avoid this would advise saving your image immediately before packaging then package and exit without saving the image Keeping Multiple Ver
154. e Availability 0 0 2 2 02 0048 9 Upward Compatibility o o 10 Common User Access Compliance 04 10 Multiple Inheritance 2 2 e 10 Porting Smalltalk Applications 0 0 0 e 10 Sources of SUpport xls da ad S el he x i 11 Talkbidk io Gy dk hose A ete to esl Rite Bae de A Bee eed 11 CompuServe 0 2 2 a 12 Usenet lt 3 ace a SLO Mae A E ee ee BA ee 12 Copyright IBM Corp 1997 iii iv Resource Catalog acta ri melnas a awe of ant Ait eae e ee 12 Learning Courses 1 2 2 13 New Features in Version3 2 0 0 00 a ee 13 New Features in Version 4 0 20000 eee ee 14 Chapter 2 General Information 2 2 23 Cleaning Up the Image 0 e 23 Creating a New Image 1 2 ee 23 Reducing Image Size e 24 Preventing Image Growth 2 000000 pee 25 AbtScrublmage 2 82 2 Aud badd bd hee ed hee Get bed Red at a 25 GROSS O i eh 26 Image Growth after Packaging 2 00 00 00 26 Keeping Multiple Versions on the Same System 26 Replacing the Default Icon 0 2 0 0 0 000000004 27 Escaping an Infinite Loop 2 0 0 000022 eee 27 File In and File Out 2 2 0 2 00 000 2 ee 28 Separate Threads 2 0 0 2 ee 28 Capturing Stack Information oaa aa 28 Renaming a Class 0 000
155. e Tivoli Management Environment For developers of VisualAge applications in a complex network computing environment Tivoli Connection provides the support for building management ready applications AppletAuthor AppletAuthor is included with each copy of VisualAge for Smalltalk Version 4 0 AppletAuthor is a Java authoring tool that lets you create applets without writing a line of Java code By combining components Java beans from a palette using simple mouse movements Web site authors can bring to life their site Once you create your applets you can include them ina Web site created with any number of Web page or site creation tools including the Web Connection feature of VisualAge for Smalltalk VisualAge for Smalltalk Handbook Fundamentals Chapter 2 General Information It seems that every Smalltalk programmer looks for tips on good Smalltalk image maintenance This chapter covers questions and answers about the image and general housekeeping Cleaning Up the Image Questioni How do clean up my image The never fail approach to reducing your image size is to rebuild it Export all of your stuff from the old image Then get a virgin image you may need to get one from the installation CD and load all of your applications It s good practice to keep a base image around that has all of the IBM and third party applications already loaded When you need to rebuild simply load your applications to the base and save u
156. e a way to delete old versions of classes from user defined applications No a version is immutable Once you version the application you have to open a new edition to make changes When we are restructuring applications we open an edition move or delete the affected classes then version the application as obsolete or do not use If the intention is to reduce the manager s size by deleting the classes be aware that deleting doesn t shrink the manager only cloning does 250 VisualAge for Smalltalk Handbook Fundamentals Getting Rid of Damaged Classes Answer Answer How do get rid of damaged classes when my image refuses to let me delete the class Version and release your classes applications and configuration maps Get a fresh image and reload your stuff How do use the exporting option to get rid of unwanted versions of my library instead of using cloning Get a new copy of the ABTMGR30 DAT file from the CD and start with that In addition to an online copy of the original manager we keep a base manager that has all of the original application versions plus any PTFs and third party applications Since we keep this base manager up to date it becomes very easy for us to purge by exporting just our applications to a copy of the base Prompting for Ownership Answer How do get an image to prompt the user for Who does this image belong to Try this Smalltalk EmUser resetlmageOwner
157. e above method explicitly signals the event telling interested parties that the ist attribute has changed VisualAge for Smalltalk Handbook Fundamentals Inheriting Visuals Associated with a View Class Tip The visual representation is considered a singular entity When you create a subclass you get a one time snapshot of the visual representation of your superclass which is then overridden when you save your subclass Think of it as a method You can override the method in a subclass and you can even copy most of the contents down for tweaking in your subclass However depending on how and what you change you may no longer be able to use superclass and any changes you make in the superclass implementation will no longer affect the behavior of your subclass The reasons you must be very careful are basically the same as the reasons why inheritance is not done automatically Changes can occur that would leave your view in an inconsistent or at least confused state For example e View1 has Buttoni e View2 inherits from View1 It adds Button2 whose left edge is attached to the right edge of Button1 Suppose you now update View1 by removing or replacing Button1 What happens to View2 Should it lose Button1 too or does it still need it If we dropped it what does that say about the placement of Button2 This is actually a simplistic scenario Others can lead to much more severe issues Connections can be very problema
158. e are however cases when automatic garbage collection GC is not enough as when you deal with operating system resources For example you can open a file and then leave the stream to GC s mercy Smalltalk myMethod f f CfsReadFileStream open MYFILE TXT self In some moment the GC will destroy the object and you are probably going to suffer In situations like this you want to be notified when the garbage collector is going to destroy an object You can do this for example by using weak pointers Point two variables to the same object one in the weak and one in the hard way then examine whether the weak pointer is nil If it is you know the garbage collector was trying to get rid of your object and you are going to do an appropriate action such as closing a file Chapter 4 IBM Smalltalk Programming Language 171 In IBM Smalltalk you have a much easier and stylish way of finalization For example you can say Smalltalk myMethod f f CfsReadFileStream open MYFILE TXT f onFinalizeDo close and don t worry any more about closing the file Standard Methods not in API Category Answer While wandering through the class hierarchy in IBM Smalltalk noticed that a number of what considered standard Smalltalk APIs were in fact in non API categories For example the value messages sent to blocks passed as parameters are in the category ES Internal The method deep
159. e create a window in OS 2 we automatically add the title to the task list The only windows whose titles do not get added are dialog windows However if you were programming this in C you would have to add the window title to the task list explicitly It should be possible to create a window in Smalltalk and not add the title to the task list Querying the Caret Position in Text Answer have an entry field such as a text edit field or multiline edit field want to know where the caret the blinking l beam cursor is within the text The parts you are talking about have the queryCursorPosition action You can use it in a script or through a visual connection It is described in the VisualAge for Smalltalk Users Reference Color Bitmap Resolution Answer How can improve the resolution on 256 color bitmaps in Windows Basically you have to set the palette of the window to be equal to the palette of the bitmap To do this connect the openedWidget event of your window to a script like the following Chapter 3 Graphical User Interface 131 Smalltalk fixColors Ask the image for its palette and set the window to have the same palette imageDesc imageDesc self subpartNamed Form1 backgroundGraphicsDescriptor self subpartNamed Form1 primaryWidget shell window setPalette imageDesc image palette self subpartNamed Form1 backgroundGraphicsDescriptor imageDesc Note
160. e for Smalltalk Handbook Fundamentals Pool Dictionaries Answer What is the exact mechanism used by Smalltalk to resolve Pool Dictionaries constant references Apparently it is not a static substitution of the value at compile time because pool dictionary entries can be dynamically changed nor believe is there a complete dictionary lookup The association key and value pair not the value itself is compiled into the method Therefore run time dictionary lookups are not needed and changes to the value done via the pool dictionary don t require any recompiling of the method Text Color Changes Answer While the application is running send the message Smalltalk self subpartNamed Text2 backgroundColor yellow foregroundColor blue show to a text subpart When put a halt anywhere in the running code then Text2 shows the changed color When don t stop in the code then the changed color is not displayed What can do to have the color change visible with a running application need this indication to know what is happening with the application Sounds like you are not giving the user interface process a chance to run Either use updateWidget to force it to update immediately or fork your work process at a lower priority Processor userBackgroundPriority and use CwAppContext default syncExecInUl to update the user interface Chapter 4 IBM Smalltalk Programming Language 19
161. e marked text into the Find window of VisualAge for Smalltalk and opens it If the Organizer is not minimized the resulting class if you search for a class is marked Here is the code for filing into your image When the application NhaTool is loaded you have the extension Chapter 2 General Information 57 Smalltalk Application create NhaTools with AbtViewApplication EtTools collect each Smalltalk at each ifAbsent Application errorPrerequisite NhaTools missing each NhaTools becomeDefault AbtViewApplicationAbtPackage subclass NhaToolsAbtPackage instanceVariableNames classVariableNames poolDictionaries NhaTools becomeDefault Application subclass NhaTools instanceVariableNames classVariableNames poolDictionaries NhaTools becomeDefault EtBrowser publicMethods defaultTextMenu Answer the modified textMenu super defaultTextMenu addLine add menuBrowse label Browse add menuFind label Find yourself EtDebugger description Developer Niclas Havrup Date 96 06 07 APAR Description Menu items add to the debugger in NhaTools 58 VisualAge for Smalltalk Handbook Fundamentals Smalltalk continued EtDebugger privateMethods defaultTextMenu Answer the modified textMenu super defaultTextMenu addLine add menuBrowse label Browse add menuFind label Find
162. e settings attributes you will store persistent in the file To save the settings in the file use Smalltalk ObjectDumper new unload lt settingsInstance gt intoFile lt aFile gt To load the settings from the file use Smalltalk settings ObjectLoader new loadFromFile lt aFile gt Connect the save action with aboutToCloseWidget the load action with aboutToOpenWidget The objectDumper unloads the complete instance into Chapter 2 General Information 39 the file in a noneditable format For redistributing you also need the ABTSWP30 DLL Extending Classes Question Why do get a prompter asking me to create a scratch edition of the base VisualAge application when want to extend an existing method Extensions can only add behavior to an existing class for instance adding new methods to add functionality You cannot alter existing methods as an extension The only way to alter existing behavior alter existing methods is to subclass and alter the methods you want to do something different in your subclass Running VisualAge from External SCSI Drive Question How can copy the entire VisualAge installation to an external SCSI drive and run it from there Just copy the whole VISUALAG directory structure to the new drive and use a command file to setup VisualAge to run from a directory so you don t have to mess with CONFIG SYS for example echo off SET BEGINLIBPATH x VISUALAG DLL PA
163. e shells but with the lack of any good documentation am in the dark on this one For the multiple key pressed events assume you are using a method along the lines Smalltalk aWidget addEventHandler KeyPressMask receiver receiver selector keyPressed clientData callData clientData nil This will get you a callback each time a key is pressed for aWidget Implementing the three keyword method keyPressed clientData callData on the receiver object results in calling it each time a key is pressed If you look at the callData object the third argument to the message it is an instance of a CwKeyEvent CwKeyEvent has a state that can indicate whether keys such as Alt Shift or Ctrl were pressed together with the original key character It is a little esoteric but the state is an integer that represents a single byte bits of which are set on or off depending on which key was pressed Fortunately CwConstants contains pool dictionary entries that identify the masks and the best thing to do is to hide this complexity on an extension of CwKeyEvent VisualAge for Smalltalk Handbook Fundamentals Smalltalk CwKeyEvent gt gt isAltPressed NM self state 8 ModiMask O CwKeyEvent gt gt isShiftPressed NM self state 8 ShiftMask 0 CwKkKeyEvent gt gt isCtrltPressed MN self state amp ControlMask 0 In your callback method if you want to see whether Shift and F10 are pressed together the code wou
164. e tab to the next entry field in VisualAge You can implement automatic tabbing in VisualAge by writing some script and making a connection to that script Suppose your have two text entry fields Go into the settings of TextField1 and set its text limit to five If you then connect the object event of the text entry field to the following script the tabbing will be done automatically Smalltalk autoTab position limit position self subpartNamed TextField1 queryCursorPosition limit self subpartNamed TextField1 textLimit position limit ifTrue self subpartNamed TextField2 setFocus If the user types five characters in the first text field focus is automatically set onto the second text field Missing Carriage Return in Multiple Line Editor 162 Question l am trying to write a string which got from a multiple line editor to a stream It seems that lose all the carriage returns by executing the following code Any help would be highly appreciated Smalltalk writeFile Write the contents of a multiple line editor to a stream fileStream mleData fileStream CfsWriteFileStream openEmpty temp txt mleData self subpartNamed Multi line Edit string fileStream nextPutAll mleData fileStream close VisualAge for Smalltalk Handbook Fundamentals Answer To solve this problem the only thing you have to do is change string to
165. ect is anything that exhibits behavior All code and data in Smalltalk must be part of an object 2 On the AS 400 system an object is a named storage space consisting of a set of characteristics that describes itself and in some cases data Some examples of objects are programs files and libraries object code Compiler or assembler output that is itself executable machine code or is suitable for processing to produce executable machine code Contrast with source code object factory A nonvisual part capable of dynamically creating new instances of a specified part For example during the execution of an application an object factory can create instances of a new class to collect the data being generated object oriented programming A programming methodology built around objects and based on sending messages back and forth between those objects The basic concepts of object oriented programming are encapsulation inheritance and polymorphism object persistency A characteristic that enables objects to exist beyond the time in which their creating application runs One use of object persistency is sharing objects among programmers in a development environment open system 1 A system with specified standards that therefore can be readily connected to other systems that comply with the same standards 2 A data communications system that conforms to the standards and protocols defined by Open Systems Interconnection O
166. ed for each key entered while the combo box has the input focus Drag and Drop Support on List Boxes Question Is it possible to have drag and drop support for list boxes The documentation only describes the situation for containers would like to give the user the ability to move an item in a list box to a new position in the same list box using drag and drop 110 visualAge for Smalltalk Handbook Fundamentals Answer The drag and drop concepts are fairly universal The nice things containers will do for you is let you specify what sort of object can be moved copied or linked Basically the drag and drop callbacks in IBM Smalltalk are exposed as events for your list box in VisualAge for Smalltalk If you open the settings for the list box and select drag drop on the notebook page the events are added to the connection pop up menu These events are exactly the same as the callbacks listed in Chapter 9 of the IBM Smalltalk Programmers Reference The following example illustrates how to drag and drop items within a list box 1 2 Add a list box to any window Open its settings and go to page Drag Drop select Allow Drag and Allow Drop and Move as the valid default operation in both cases Use any collection as the items of the list as usual Connect the dropped event of the list to the following script Smalltalk moveltems aCallback items itemsDropped position index items aCallbac
167. eferences Workspace Scroll down a bit to find the following line within the Configuration Management section Smalltalk EmTimeStamp showVersionTimeStamps false Change false to true swipe the line and execute Note This still shows only the timestamp of the edition that is when the edition was created not when it was versioned Applications and Subapplications Question l am not quite sure when to use applications and when to use subapplications Would someone please explain the differences and the criteria generally used for determining when a set of classes are considering a subapplication Subapplications are used for functional grouping or for class extentions that need platform specific functions or supports By default when you load an application all its subapplications will also be loaded Especially for platform specific support an application will have some configurable expressions to specify which of its subapplications should not be loaded on a certain platform Connecting to a Cloned Library Question Can connect an old image to a cloned library Yes you can but recache your pointers Never connect an old image to a cloned library without having recached your pointers first Otherwise your cloned repository could get corrupted 248 VisualAge for Smalltalk Handbook Fundamentals Reloading an Application Answer How do in code reload the currently loaded edition of an ap
168. em Transcript window back to its default message Preventing Image Growth Question What should look for if my image size is increasing over time Execute System abtScrublmage Does your image size shrink considerably If so it is time to figure out where you are hanging onto resources There are several possibilities here Check the following AbtScrublmage Open a debugger You can open a debugger from the Transcript by selecting Smalltalk Tools Open Debugger or from the VisualAge Organizer Tools Debugger To see the Debugger item in the Tools pulldown menu select Options gt Full Menus in the Organizer From the Debugger s pull down menu select Processes gt Debug other There should be only two processes the CwAsynclOProcess process and the Idle process If there are others you should attempt to figure out what objects are suspending them and holding onto them With no windows but the Transcript and VisualAge Organizer open inspect the AbtEventDependents classVariable of AbtCLDTAdditions There should be only two entries If there are more then you have dependencies that are not being released This most often occurs when sending closeWidget as opposed to performing the action closeWidget The selector corresponding to the closeWidget action is closeWidgetCommand Sending closeWidget will prevent dependencies from being freed Question Vve heard many times about abtScrublmage that it helps me reduce my image siz
169. endpoint for communication between processes or applications A socket that can send data to and receive data from a remote node is a connected socket 2 Synonym for port socks Software to intercept and redirect all TCP IP requests at the firewall It handles data to and from applications such as Telnet FTP Mosaic and Gopher Provides users in a secured network access to resources outside the network by directing data through the firewall Firewall users must use client programs specifically designed to work with the sockd server software 1 Programs procedures rules and any associated documentation pertaining to the operation of a system 2 Contrast with hardware SOM See system object model source code Compiler or assembler input written in a source language Contrast with object code source file A file of programming code that is not compiled into machine language A source file can be created by the specification of FILETYPE SRC on the Create command A source file can contain source statements for such items as high level language programs and data description specifications DDS SQL Structured Query Language A language used to access relational databases SQL Editor An interactive tool for creating structured query language SQL statements It consists of a set of dialogs that prompt the user for information about database tables and use that information to generate SQL statements statemen
170. eneous network U uniform resource locator URL A standard identifier for a resource on the World Wide Web used by a Web browser to initiate a connection The URL includes the communications protocol to use the name of the server and path information identifying the object to be retrieved on the server usability The quality of a system program or device that enables users to easily understand and conveniently use it user interface UI The hardware software or both that enables a user to interact with a computer In VisualAge user interface normally refers to the visual presentation with which a user interacts and its underlying software user profile A file that contains the user s password the list of special authorities assigned to a user and the objects the user owns It is used by the system to verify the user s authorization to read or use objects such as files or devices or to run the jobs on the system Each user profile must have a unique name user space In OS 400 application programming interfaces an object consisting of a collection of bytes that can be used for storing any user defined information The system recognized identifier for the object type is USRSPC V variable 1 A storage place within an object for a data element The data element is an object such as a number or date stored as an attribute of the containing object 2 In VisualAge a part that receives an identity at
171. entals source code is stored This may allow for method changes at a faster rate than manual input A 1 GB drive should give you very comfortable room for development Even though you may not need that much a 1 GB drive should be cheap enough today to buy that luxury where a 300 MB or 500 MB drive would risk the later discovery that you ll have to spend time to move the manager to a larger drive Anyway make sure that your team has a good reliable means to back up the shared manager file You don t really need to back up each developer image file as the files can be rebuilt from the manager or library file And make as frequent daily weekly a backup schedule as you can afford Class Changes versus Alternatives Question What is the difference between class changes and class alternatives found the following information in an ENVY Manager user manual hope the information is helpful e File Out Changes File out methods in the primary class editions that are different from the corresponding methods in the alternative class editions File Out Alternatives File out methods in the alternative class editions that are different from the corresponding methods in the primary class editions Primary seems to indicate the editions that appear in the left pane of a changes browser Alternative method editions appear in the right pane of the browser Moving Windows Library to AIX Question We are developi
172. epending on how much is trashed and what the trash looks like Also according to OTI there is no way for customers to either protect against a stack overflow or know when one has occurred Many of our customers run quite successfully with the original stack size of 32 KB However as VisualAge for Smalltalk applications have become more complex stack usage has increased Therefore before the Version 3 0a refresh ABT EXE was rebuilt with a 64 KB stack It has been noted that a 64 KB stack is not always enough either So have developed a version of ABT EXE that runs Smalltalk on a thread This allows customers to set any stack size they need It also keeps Smalltalk called DLLs from writing past the end of the stack based on the different mechanism used for managing thread stacks vs the main thread stack When you get a report of a SYS317x on IBM Smalltalk or VisualAge for Smalltalk that occurred while running the product not during install for example here are some steps to diagnose and correct the problem 1 Does the trap occur when the user is doing lots of user interface interaction If so suggest that users update their video drivers to the newest level and retry In the past we ve seen this kind of problem on Windows but it is also beginning to show up on OS 2 It seems to be most prevalent with S3 based video cards but has been seen with others Diamond Stealth drivers seem to be particularly notorious for causing this p
173. er components that can be loaded and unloaded during program execution ICs enable a more fine grained packaging system and allow multiple applications to share the client s run time image which improves performance and footprint and further promotes reuse Performance of database applications will improve under Version 4 0 and DB2 applications can now be improved substantially by using static SQL Tool enhancements include a more robust debugger allowing for static and conditional breakpoints and profiler enhancements that provide for easier fine tuning of an application s performance VisualAge for Smalltalk has also improved its external callout and callback support allowing non Smalltalk applications to communicate more easily with Smalltalk applications Several Version 3 0 optional features have been moved into the base including native Oracle support Connection for Lotus Notes Reports a leading edge object visualization tool and Pro Server providing the best value in the industry Management of applications is improved by including parts that allow your application to interact with the Tivoli system management products Also included with each copy of Version 4 0 is AppletAuthor which allows you to create eye popping Java applets that lead to dynamic visually appealing Web sites without the need to know Java programming Additional Platforms and Windows Platform Exploitation Platform choice has been a hallmark of VisualAge
174. erface The reason is that the interface actually inherits these actions We are looking for a way avoid having unsupported features show up in the public interface Removing an Icon Questioni How come when you remove an icon from the icons collection of a container it is still visible in the container view Chapter 3 Graphical User Interface 125 Answer It is likely that the container does not get refreshed There are a couple of solutions to that You can send a refreshAll to the container which will update the view You can also tear off the items attribute and use the following code to do the same Smalltalk self subpartNamed itemsCollection performActionNamed remove with anltem Adding Icons Dynamically 126 Answer How do dynamically add icons to a container and use context menus in different variations To learn how to dynamically add icons to a container during run time instead of statically during development time see the example in the VisualAge for Smalltalk Users Guide and Reference pages 229 236 This example allows you to use a context menu while clicking the second mouse button anywhere in he container surface except on top of the icons There are other ways to use the context menu For instance you may want to be able to bring up the context menu while clicking the second mouse button both on the container surface and on top of the icons To do this you just have to modify the f
175. erform as well as or even better than some C applications which may display many complex notebook objects The notebook snaps open and clicking on the notebook pages is immediate Tabbing Order 158 Answer Is there an explanation somewhere of how to set tabbing order in a variety of situations The simple case is straightforward and one can happily drag the yellow tags around to change the order But what do the blue tags mean and how are they manipulated Also how can you create different traversal groups for separate groups of buttons Suppose you have a form which contains a set of buttons plus another group of buttons directly placed on the window The yellow tags show 3 1 and 3 2 on the directly placed buttons but there is a blue tag showing 3 on the buttons form The form gets tabbed to first when you want the other buttons to be tabbed to first Is there a way to change this When you see 1 2 3 whether it s blue or yellow that means it is a tab group and you use the tab key to navigate to or from it In this case yellow indicates that it is a tab group consisting of one part only An example would be an entry field Blue indicates that it is also a tab group but that it has multiple parts within it An example would be the form with multiple push buttons in it You typically want to navigate between push buttons using the arrow keys so when you place push buttons directly on the window it defaults
176. ers programming tips for the IBM Smalltalk language Smalltalk Books Question What mass market Smalltalk books are available Answer Copyright IBM Corp Smalltalk 80 The Language Adele Goldberg amp David Robson Addison Wesley 1989 ISBN 0 201 13688 0 Smalltalk 80 The Interactive Programming Environment Adele Goldberg Addison Wesley 1984 ISBN 0 201 11372 4 Smalltalk 80 Bits of History Words of Advice Glenn Krasner Addison Wesley 1984 ISBN 0 201 11669 3 Inside Smalltalk Volume I Wilf Lalonde amp John Pugh Prentice Hall 1990 ISBN 0 13 630070 7 Inside Smalltalk Volume II Wilf Lalonde amp John Pugh Prentice Hall 1991 ISBN 0 13 465964 3 Object Oriented Graphics P Wisskirchen Springer Verlag 1990 Practical Smalltalk Using Smalltalk V Dan Shafer and Dean A Ritz Springer Verlag ISBN 0 387 97394 X Rapid Prototyping for Object Oriented Systems Mark Mullen Addison Wesley 1990 ISBN 0 201 55024 5 Object Oriented Design Peter Coad and Ed Yourdon Yourdon Press 1991 Object Oriented Programming for Artificial Intelligence Ernest Tello Addison Wesley 1989 ISBN 0 201 09228 x The Well Tempered Object Stephen Travis Pope MIT Press 1991 ISBN 0 262 16126 5 Human Computer Interface Design Guidelines C Marlin Brown Ablex Publishing 1989 ISBN 0 89391 332 4 Designing Object Oriented Software Rebecca Wirfs Brock Brian Wilkerson and Lauren Wiener Prentice Hall 1990 ISBN 0 13 62982
177. es below it shows extra zeros Chapter 4 IBM Smalltalk Programming Language 183 184 Smalltalk 1502 03 printStringWidth 30 1502 0299999999999700000000000 1051 42 printStringWidth 30 1051 4200000000000700000000000 Now calculating the difference we see that the expected answer 450 61 is not quite what we get Smalltalk 1502 03 1051 42 printStringWidth 30 450 60999999999990000000000000 450 61 printStringWidth 30 450 61000000000001000000000000 1502 03 1051 42 printHex 1 C29C28F5C28F4e8 450 61 printHex 1 C29C28F5C28F6e8 In fact the difference is just in the rightmost two bits but that s enough to make it not equal Now what do roundTo and truncateTo do Smalltalk 1502 03 1051 42 roundTo 0 01 printStringWidth 30 450 61000000000001000000000000 1502 03 1051 42 truncateTo 0 01 printStringWidth 30 450 60000000000002000000000000 Clearly equality testing is not going to work But consider the following Smalltalk 1502 03 1051 42 between 450 605 and 450 615 which does answer true and will answer true unless and until the real internal precision gets very much smaller or the values get much much larger The former is not likely when doing currency calculations A method which does the between and test for floats is VisualAge for Smalltalk Handbook Fundamentals Smalltalk Float publ
178. es block with all files on pathname which match the provided pattern Note that only the names of files are provided no full paths directory entry directory CfsDirectoryDescriptor opendir pathName pattern pattern mode FREG directory isCfsError ifFalse entry directory readdirName notNil whileTrue block value entry directory closedir FREG is an entry in the pool dictionary CfsConstants The mode keyword in the message opendir pattern mode uses flags to determine which files to find FREG provides the names of all regular files FDIR provides the names of subdirectories To get both the names of files and directories pass FREG FDIR as the parameter to this keyword VisualAge for Smalltalk Handbook Fundamentals Use this method to print the names of all text files in the root directory the following code assumes the above method has been implemented in a class called FileManager Smalltalk FileManager filesMatching txt on do fileName Transcript cr show fileName The root directory can be specified as a forward slash which is very UNIX This works in OS 2 and in Windows as well as in AIX It may be handy to get a collection containing the file names Smalltalk filesMatching pattern on pathName Answers a collection with all files on pathname which match the provided pattern Note that only the names of files are provided no full paths
179. ession data A Web Connection nonvisual part that holds a persistent data object You can use CGI Link Session Data to store an application specific object that remains valid from one CGI query to the next for the duration of a session change event symbol In VisualAge the code used to signal that an attribute has changed in value character A symbol used in printing For example a letter of the alphabet a numeral punctuation or any other symbol that represents information character literal A literal that is any single character preceded by a dollar sign CICS See Customer Information Control System class The specification of an object including its attributes and behavior Once defined a class can be used as a template for the creation of object instances Class therefore can also refer to the collection of objects that share those specifications A class exists within a hierarchy of classes in which it inherits attributes and behavior from its superclasses which exist closer to the root of the hierarchy See also inheritance metaclass polymorphism private class and public class class definition The definition of a class containing Class name e Type of class Immediate superclass for the class e Instance class and class instance variables e Pool dictionaries that the class uses class developer A team member who develops and changes classes The team member who created an edition of
180. etting the simple packaging process to include all keys and values of two application specific pool dictionaries that are used in one of the classes in my application The packager seems to be excluding all keys values in these pools unless code a rather ugly method which explicitly refers to all keys values in these two pools What do do Chapter 2 General Information 51 Answer Are you referring to your pool dictionary entries by name for example are you using at to look them up If you are you ll need to inform the packager not to reduce the pool By default the packager will remove any entries that are not directly referenced To prevent this add a packaging rules class method to your application class like the one below The packager will not do pool reduction if a rule has been explicitly set Smalltalk aPackagedlmage includeGlobal MyPoolDictionary Application Prerequisites Of the problems we have encountered with packaging 90 have been problems with prerequistes With the team version of VisualAge it is possible to partition your deliverable across multiple applications Each application has certain requirements that must be met for an image to make sense For example if an application introduces a new class the superclass must be available either in the same application or in a prerequisite application It can be said that one application needs others to be in memory to work It is also worth mentioni
181. eved by Smalltalk execLongOperation aBlock with your long running stuff message Il am thinking please wait But to be honest this is only half the story because the message is implemented by AbtShellView That means you have to send it to the current window That in turn leaves the problem how to find the actual window for example the one having the focus You could use something like this Smalltalk CwTopLevelShell allShells reverseDo sh sh hasFocus ifTrue sh userData This method returns the window having the focus and accepts the execLongOperation message message If you don t pick the window having the focus the focus in your application changes to the window you reference This is quite confusing for users at least so they tell me The above examples work in Version 3 and have not been tested in any other version Chapter 3 Graphical User Interface 155 Progress Messages Answer How are the progress messages in the browsers implemented The CwProgressDialog implements the in progress indicator no buttons just a message and a bar Limiting the Number of Lines in Multiple Line Editor Answer We need to limit user input to 30 lines with 60 characters per line Is there a way to do this using a multiline editor part see only the ability to specify 1800 30 60 characters as the maximum number for the multiline editor part This won t do because the user
182. evelopers use a construction from components or construction from parts paradigm when using VisualAge VisualAge is based on IBM Smalltalk which embodies the principles of object oriented OO technology to build applications providing all of the benefits of reuse and rapid application development With VisualAge s GUl based development platform proficiency in OO is not a prerequisite thus easing a developer s entry into OO Copyright IBM Corp 1997 1 Description of Smalltalk Answer What is Smalltalk Smalltalk is a popular OO language Often referred to as a 5GL Smalltalk is a very powerful high level language that offers exceptional capabilities for rapid prototyping and delivery of applications It is an emerging language in the programming environment Smalltalk has been around since 1971 It was developed in Xerox PARC and it was the first system in the history of computers featuring a GUI with windows mice and other properties of the modern graphical operating systems IBM Smalltalk is a portable robust standards compliant integrated Smalltalk language and development environment embedded as a component of VisualAge IBM Smalltalk adheres to industry standards such as OSF Motif and POSIX and is based on the proposed common base Smalltalk specification submitted to the X3J20 committee for making Smalltalk recommendations to ANSI Description of ENVY Answer What is ENVY ENVY is an incredibly powerful
183. ext yourself Getting the Anchor Block Handle Questioni How do get the anchor block handle of a primary visual part Here is an example of how you can get the anchor block handle of your primary visual part Smalltalk self subpartNamed Window yourself primaryWidget osWidget handle winQueryAnchorBlock Turning Off Error Message Question How do I turn off the error message error that is shown by data converters such as AbtStringConverter on text parts Turn off the setting reformatOnFocusChange for each of the text fields you wish to affect You can do this in the settings notebook Chapter 3 Graphical User Interface 135 Locating the Focus Questioni How can I determine which form contains the widget that has the focus The following code shows how you can determine which widget has the focus Smalltalk queryFocusForm focusWidget focusView focusWidget self shell focusWidget focusWidget notNil and focusView focusWidget userData isKindOf AbtBasicView ifTrue focusView notNil and focusView isKindOf AbtFormView whileFalse focusView focusView parentView focusView Note that userData of the widget of AbtBasicView subclasses refer back to their view You could accomplish the same thing by iterating the target form components and comparing their widget against the focus widget but the above is quicker Bitmaps on Buttons Question
184. f your LIBPATH and PATH statements in your CONFIG SYS file on OS 2 before starting VisualAge This is an OS 2 Warp limitation Video Disk Player Tip The wrap function does not work for the video disk player 84 VisualAge for Smalltalk Handbook Fundamentals Crystal Wave and MWave Audio Cards When running video or audio under OS 2 on a Crystal Wave Audio or MWave audio card the video or audio might not terminate and thereby lock up VisualAge Installing more recent audio drivers might help solve this problem Using a different audio card such as SoundBlaster will solve the problem AVA Playback Windows Lotus Notes An AVA Playback Window in a scene of a story enables the user to use Ctrl Esc to escape that scene in a full screen presentation even if the Prevent user exit option is on This is an Ultimedia Builder limitation On DBCS systems a Notes database title might be truncated when displayed in a Notes database icon You can view the entire title in the database properties dialog This problem occurs when the database name is longer than 32 bytes which can occur with as few as 11 Lotus multibyte characters LMBCS Depending on the type of characters in the database title such truncation might lead to an unviewable character at the end of the title Chapter 2 General Information 85 86 VisualAge for Smalltalk Handbook Fundamentals Chapter 3 Graphical User Interface In this chapter we cover issues
185. figuration maps specific versions of specific configuration maps to an empty DAT library I d like to do this without the user interface so that can run this unattended overnight Do you have a script that can do this You can do this without a script Select export from the pop up menu in the configuration maps pane not the versions but names of the configuration maps browser Then select the target library and you ll be prompted for all map or version pairs up front Manager Growth Rate 254 Answer What is the approximate rate of the Manager file growth on the server heard about 1 MB per day per developer Is it true It comes down to how much code your developers can crank out or change per day If they migrate some existing application into a brand new VisualAge for Smalltalk library chances are the library will grow with however much code is being migrated into the manager If your developers write Smalltalk code from scratch keyboard input chances are that they won t be able to type anywhere near 1 million key strokes of desirable Smalltalk code per day One can try for half that on a DBCS input Modifying an existing method may store incremental changes only I don t deal with that algorithm If you make changes via the VisualAge for Smalltalk Composition Editor the run time code is stored as various methods so there won t be much difference in the way method VisualAge for Smalltalk Handbook Fundam
186. file name and then register the mapping file name with the locale character as a wild card Modifying Data Entry Parts Answer Is there a userModified event for data entry parts The available events are losing focus which occurs whether the field value has changed or not and object which is triggered for any changes including user and programmatic changes Reacting to Keyboard Input How do receive keyboard input and react to it Chapter 3 Graphical User Interface 141 Answer You can set up an event handler to handle key press events and check for the F4 there See page 188 of the IBM Smalltalk Programmer s Reference for a description and example of this Add an event handler to your window Smalltalk self subpartNamed Window primaryWidget addEventHandler KeyPressMask receiver self selector keyEventHandler clientData event clientData nil Then you handle the event like this Smalltalk keyEventHandler widget clientData clientData event event Transcript show event keysym printString Using Esc to Close Nonmodal Dialog 142 Questioni Can I use Esc to close a nonmodal dialog Since you are bringing up a dialog the Esc key is mapped to close by the CwDialogShell class see AbtShellView class gt gt cwModalWidgetClass and AbtShellView gt gt primCreateWidget for details If you do not set an owner window the CwTopLevelShell is used as the shell class see AbtShellView cl
187. fset of zero Now when you drop your push buttons inside the row column they automatically space apart making a tool bar a little easier to deal with Synchronizing a Combo Box Question Suppose you have two combo boxes dropped on a window The first combo box contains a set of names while the second combo box contains valid descriptions for each of these names How can you synchronize the two in such a way that when you type an invalid code in the first combo box the second one will be cleared Chapter 3 Graphical User Interface 109 One of the ways of doing this is just to connect the selectedindexChanged event of the first combo box to a script where you validate the index and modify the second combo box accordingly Adding Items to Combo Box Question How do I allow a user to add new items to a combo box e Hook a keyboard event handler to the comboBox e Within the event handler sort out any Enter keys e Whenever you encounter an Enter key you do something like Smalltalk lt combobox gt items add lt combobox gt object In order to invoke the keyboard event handler you hook a method to the aboutToOpenWidget event of your main window in this script you include Smalltalk lt combobox gt widget addEventHandler KeyReleaseMask receiver self selector keyRelease clientData event clientData nil Then you can add a keyRelease clientData event method to your class which will be call
188. g asPointer Vol2 97 finding in methods 232 formatting 173 identity 221 literal 221 227 padding 223 parsing 219 removing blanks 223 replacing character 222 substitute 173 substring 186 trimming 223 subapplication using 248 subclass visual part 204 215 substrings 186 subsystems configured 199 successor uniqueness violation Vol2 109 swapper error 198 large objects 217 loading application 47 swapping 174 sweeps 211 Sybase 8 symbol as dictionary key 235 synchronizing attributes 45 combo box 109 image 243 table scrolling 148 visual part 202 windows 95 334 VisualAge for Smalltalk Handbook Fundamentals synchronous RPC Vvol2 40 syncpoint processing Vol2 75 SYS317x error 72 system connected Vol2 17 menu 41 menu modifying 41 system object model See SOM T tab group 158 order 143 158 tabbing automatic 162 enter key 153 table adding column 146 changing cell 149 changing format 36 changing size 149 creating in Smalltalk Vol2 161 hiding column 145 list 149 resizing rows 224 reusing part 149 153 scrolling 148 selecting multiple rows 150 sizing 149 synchronizing scrolling 148 widths 153 TalkLink 11 target environment packaging in 47 task list 131 TCP IP address in use Vol2 66 AS 400 communication Vol2 51 ClientAccess 400 Vol2 50 DDM Vol2 50 distributed name server Vol2 201 distributed testing Vol2 202 fault tolerance Vol2 220 handling addresses Vol2 213 hard coded addres
189. g performance profiling for optimal distribution and other features that complement the development environment e VisualAge for Smalltalk Database for Oracle for OS 2 for AIX and for Windows V3 0 provides access to Oracle data through native APIs Access to Oracle and other databases through ODBC is also provided in the base products e VisualAge for Smalltalk Reports for OS 2 and for Windows V3 0 enables you to lay out reports using the facilities of the VisualAge for Smalltalk construction from parts paradigm e Message Queue Series MQSeries support and remote procedure call RPC support as part of VisualAge for Smalltalk Communications Transactions for OS 2 for AIX and for Windows V3 0 e System Object Model SOM and Distributed SOM DSOM 2 1 Client support OS 2 and AIX only e VisualAge for Smalltalk AS 400 Connection for OS 2 and for Windows V3 0 enables you to access additional AS 400 services objects and data along with additional parts for VisualAge for Smalltalk e VisualAge for Smalltalk IMS Connection for OS 2 for AIX and for Windows V3 0 enables you to wrap existing IMS transactions to be used as parts within the VisualAge for Smalltalk environment New Features in Version 4 14 Question What are the new features in VisualAge for Smalltalk Version 4 VisualAge for Smalltalk is IBM s award winning enterprise application development tool that is the cornerstone of IBM s VisualAge family
190. g an Icon How do remove an icon from the container icon view Your problem may be that the container does not get refreshed There are a couple of solutions to that 1 Send a refreshAll to the container 2 Tear off the items attribute and use something like this 128 VisualAge for Smalltalk Handbook Fundamentals Smalltalk self subpartNamed items of blahblah performActionNamed remove with anltem That causes a refresh of the container as well You want to signal that the items have been updated and then anything connected will refresh Error Attribute Does Not Exist Answer In the container details part what causes an attribute does not exist error Each of the objects in the items collection must have the attribute shown in the column header to get the data to display If any of them doesn t you will get an error Adding an Icon to A List Part Answer How do set up a list part that can show an icon in the first column followed by several detail columns You need to use a details tree container part First the column parts should have an attribute to display value specified in their settings view Second the objects that you are using as the items should have methods with the names you specified in the attribute to display fields of the column part s settings For the column that is to display the icon its attribute to display method should answer return an instance
191. g compiled which you d like to run has not yet been inserted into the system Thus you run the last one that was compiled And the next time you run this one and so on Chapter 4 IBM Smalltalk Programming Language 169 Warning Vve discovered that writing to the Transcript from within has some problems Weak Pointers Answer What does the term Weak Pointers mean Can use weak pointers in IBM Smalltalk Weak pointers are pointers you can have to objects that do not prevent the garbage collector from destroying the objects In other words if there are only weak pointers to an object and no other pointers the garbage collector will destroy the object You can use weak pointers in IBM Smalltalk for example Smalltalk string array string String new 100 array Array new 10 makeWeak array at 1 put string string onFinalizeDo halt You ll get a walkback the next time the finalize cycle runs when the system goes idle Utility of Weak Pointers 170 Answer Do weak pointers have practical importance Can you give a couple of examples of when might want to use them and what they buy me In VisualAge a large number of collection classes have the word weak in their name lIl just mention briefly some usages of weak objects here Below will talk only about a simple collection like Bag Set OrderedCollection and not Dictionary or LookUpTable Various
192. g enterprise business problems for business logic application development C and Smalltalk are equivalent in capability for well trained and skilled developers Chapter 1 What Is VisualAge for Smalltalk 5 Visualizer Questioni How does Visualizer compare with VisualAge for Smalltalk Visualizer is a powerful decision support tool that allows end users to visually construct database queries and generate reports It also features add on components up to and including a GUI builder VisualAge is targeted for professional developers rather than end users Team Connection Questioni Does VisualAge for Smalltalk support Team Connection VisualAge provides team support using an object repository that is tightly integrated in the product and that provides a high level of support for Smalltalk based development Our direction is to expand this excellent object repository with bridges to other technologies such as TeamConnection Supported Platforms Question On which platforms is VisualAge for Smalltalk offered dale VisualAge is available on e OS 2 Warp Version 3 or Version 4 e Windows 3 11 e Windows 95 e Windows NT 3 51 or 4 0 e AIX 4 1 4 or 4 2 e Sun Solaris 2 5 1 e HP UX 10 10 6 VisualAge for Smalltalk Handbook Fundamentals Smalltalk Strategy Questioni Is Smalltalk strategic Smalltalk is a strategic language for IBM and will be developed as a standards compliant open multiplatform lang
193. ge 156 prompter bypassing Vol2 142 changing labels 160 creating 161 data source name Vol2 148 labels 139 properties view 75 protecting library 244 PTF ClientAccess 400 Vol2 135 data queue Vol2 31 QGYSETG Vol2 34 remote command Vol2 53 330 VisualAge for Smalltalk Handbook Fundamentals purging application 250 push button apply 38 bitmap 161 disabling 156 dynamic 160 graphical label 32 hover help 32 157 198 icon 157 Q QENVAUXD vol2 12 QENVY Vol2 12 QEVYMAIN Vol2 23 Vol2 34 QGPL Vol2 43 QGYSETG Vol2 34 Vol2 53 QIWS Vol2 23 Vol2 34 QTEMP Vol2 43 query host variable Vol2 162 message SQLO805N Vol2 173 missing fields Vol2 171 sharing Vol2 145 tables and views Vol2 170 URL string Vol2 253 queue handle Vol2 78 manager Vol2 78 quick form Vol2 3 Vol2 146 R recaching pointer record 243 248 adding to container 120 AS 400 Vol2 3 blocking Vol2 19 commitment control Vol2 59 deriving description Vol2 48 description Vol2 3 Vol2 31 Vol2 35 filling from data queue Vol2 6 locking Vol2 45 logical format Vol2 47 read next Vol2 4 read previous Vol2 4 repeated structures Vol2 37 record continued transaction Vol2 109 unique key Vol2 46 reduced runtime image 47 reducing image size 23 reference circular 97 object 206 referential integrity Vol2 55 refreshing container details view 127 registered connection removing 30 events 260 registering OS even
194. ge management in the IBM Smalltalk Professional version and and Motif based GUI widgets that work on all platforms Caching Compiler Questioni Is the IBM Smalltalk compiler a caching compiler Absolutely IBM Smalltalk moved from being one of the slowest to being the fastest with Version 3 Creation of Blocks at Run time Questioni Is it possible to create and execute blocks of Smalltalk code at run time For example want to read a block from a file The string read should then be converted to a Smalltalk block and this block should be executed The basic answer is no because you need to ship the Smalltalk compiler as part of your application and that s not allowed in the Smalltalk license agreements The fuller answer is to ask why you want to do this Are you dynamically creating blocks in response to say user input or just selecting one block from a collection stored on disk If the former you will need some sort of compiler or interpreter to translate the user s input to the blocks in the first place so you could instead produce an interpreter that works on the user s input and store that input on disk instead of the block you would have produced If you are just selecting a block from a collection perhaps you should be creating classes that all implement a behavior according to the user s input the methods that implement these behaviours contain the code that would have been in your blocks 192 VisualAg
195. ght be helpful e Have a small image to run packaging from containing only the absolute minimum classes and methods no other applications no samples no unnecessary infrastructural support e Do not use standard method names as the packager seems to determine class and method exclusion by name disregarding the class context for method names For example calling a packaged and needed method doSomething will package every method called doSomething that is found in your entire development image which will include every class e Get the prerequisites right having unnecessary or wrong prerequisites can be fatal possibly resulting in an 8 MB package instead of the normal 2 MB Including Classes in a Package 46 Question We create a complex object outside of our application and dump the object to disk using the ObjectDumper class This dumped object contains a collection of Catalog objects and each Catalog object contains a collection of Part objects and collections of Vehicle objects After dumping this object to disk the object remains static so our application can use it discovered that when we packaged our application objects such as Catalog Part and Vehicle are not included in the package To get around this am creating an instance of these classes and finally letting them be collected as garbage Not doing this results in an error after using the ObjectLoader saying the Class definition was missing
196. gle argument That argument is an instance of class Signal Tell the signal what to do next e exitWith Exit the block with some value e retry Reattempt evaluation of the block e signal Pass the responsibility for handling the error to the outer context File System Errors Questioni How do catch file system errors The following method opens the file named by its first parameter The second parameter is a block to evaluate in the event of an error Smalltalk contentsOfFileNamed fileName ifError errorBlock Answers the contents of the text file named aString If an error occurs then the result of evaluating errorBlock is answered file contents file CfsReadFileStream open fileName file isCfsError ifTrue errorBlock value contents file contents when ExCFSError do signal signal exitWith nil file close contents notNil ifTrue contents errorBlock value 180 visualAge for Smalltalk Handbook Fundamentals First the file is opened If an error occurs during the opening of a file the result of the open message will be an object that answers true to isCfsError Second the attempt to read the contents of the file is wrapped in a block That block is sent the message when do The first parameter to this message is the kind of error we are interested in ExCFSError in this case and the second parameter is a block containing the code to evaluate in the event that
197. gned Contrast with deactivate activator In distributed processing environments a program running in the background sometimes called a daemon process that initially activates other programs the first time they are called active 1 Able to communicate on the network A token ring network adapter is active if it is able to transmit and receive on the network 2 Operational 3 Pertaining to a node or device that is connected or is available for connection to another node or device 4 Currently transmitting or receiving Copyright IBM Corp 1997 adapter Hardware card that allows a device such as a PC to communicate with another device such as a monitor a printer or other I O device address 1 In data communication the IEEE assigned unique code or the unique locally administered code assigned to each device or workstation connected to a network 2 A character group of characters or a value that identifies a register a particular part of storage a data source or a data sink The value is represented by one or more characters 3 To refer to a device or an item of data by its address 4 The location in the storage of a computer where data is stored 5 In word processing the location identified by the address code of a specific section of the recording medium or storage Advanced Program to Program Communication APPC 1 IBM s architected solution for program to program communication
198. h of these examples answer 1 02 on a machine where the decimal separator is defined as VisualAge for Smalltalk Handbook Fundamentals Garbage Collection of Instances Answer Is there a fast way to get rid of unwanted instances Suppose these instances are in a linked list so that they are always referenced You could use the allInstances method to find all the instances and make them become String new However this is very slow so another thing you could do is create a class variable to store all the instances then when it is time you make them become String new Even if you cache the instances in the class variable the process of become String new is still very slow Now how can you quickly remove these instances so they can be garbage collected The best way by far to solve a problem like this is to find the source Then you don t have to try and solve the symptom with things like become You need to determine the critical reference A linked list is not a problem The garbage collector is capable of detecting circular references and will collect such objects if they are not referenced by anything outside the circular list That is in your case something else is holding on to something in that linked list It is difficult to find out which item in the list is the being referenced You might try running System abtScrublmage lf your linked list goes away then see which of the steps freed your object by c
199. h path The search starts at the working directory and then works its way down the entries in nlspath You can see which MPR each nlisgroup is bound to by executing this code fragment Smalltalk AbtMRIManager requestsAndResolutions do aRequest Transcript cr nextPutAll aRequest request printString aRequest isResolved ifTrue Transcript tab tab nextPutAll aRequest resolution fileSpec fullName ifFalse Transcript tab tab nextPutAll not resolved Code Page Conversion between OS 2 and Windows 266 Answer How can develop an application with VisualAge for Smalltalk for OS 2 and then reuse it from VisualAge for Smalltalk for Windows where the code page in OS 2 is 850 and in Windows it s 437 Windows uses code page 819 ISO 8859 1 regardless of what the code page is set to in DOS The code page for DOS my be 437 but Windows ignores it Code page 819 doesn t exist in OS 2 Although OS 2 doesn t support code page 819 code pages 819 and 850 have consistent mappings for points 32 126 After that it is hit or miss as to whether or not they match In Version 3 of VisualAge for Smalltalk we automatically map the characters in label strings messages and the like to the correct code points for you In Version 2 0 however you have to do the mappings yourself The easiest way to do this is to select the separate application strings option for the application you want to run in both OS 2 a
200. h visual programming for developing line of business client server solutions VisualAge Generator provides facilities for building both client and server components interactive test at the source level and generation of both client and server VisualAge for Smalltalk is a fully object oriented tool providing a visual programming construction from parts paradigm and uses IBM Smalltalk as the scripting language VisualAge for Smalltalk focuses on building client server solutions while providing extensive database access communications support and support for reusing existing enterprise data and code The products are complementary Each has its own strengths In some customer situations one of the products may provide the right solution whereas in others the entire solution may dictate that both products provide the ultimate benefit For users wanting to explore the world of object oriented programming while maintaining a 4GL development environment VisualAge for Smalltalk should be a very attractive addition VisualAge for Smalltalk and C Answer How would you compare VisualAge for Smalltalk and VisualAge for C C is the language of choice for the professional C or C programmer building high performance small footprint or real time applications for close to the metal application development Smalltalk is the language of choice for the professional programmer who wants a rapid application development environment for solvin
201. he collection which is created based on size and characteristics If you look in OrderedCollection class gt gt new you ll see that it actually works with an EsLinearOrderedCollection SortedCollection is more interesting since you ll see in SortedCollection Class gt gt new it creates either an EsInsertionSortedCollection or an EsHeapSortedCollection VisualAge for Smalltalk Handbook Fundamentals depending on if there are 16 or fewer elements The InsertionSorted implemention does an insertion sort where the heap does a Heap sort For fewer than 16 elements the insertion sort is faster than doing a heap Thus the SortedCollection new starts life as an insertion sorted collection then changes to heap sorted collection when we get to 17 elements The ImplementationCollection instance variable keeps track of the details of what object is really represending the list and if remember right this is a strategy pattern Fixed Object Space Question Does IBM Smalltalk have fixed object space Yes We have a message called makeFixed that will protect an object from garbage collection That is makeFixed relieves the garbage collector from having to flip around lots of long lived objects at the cost of manual deallocation Parsing Strings with Date Time Question Is there a method for parsing a string to get an instance of Date That is to do something like this Smalltalk 08 23 93 asDate and receive a
202. he memory used by these instances Finding Methods Containing a String 232 Answer How would one locate a string within a given class or application in IBM Smalltalk thought this would be trivial given the rich set of text comparison tools but can t find any tools or menu selections to make this easy For example want to search through application A to find all methods that contain the text string B Does anyone have a swatch of code could use for this I d like to extend the Envy browsers to make this function accessible but code that one can evaluate in a workspace would be wonderful If you are looking for methods referencing a given literal sending Smalltalk System allMethodsReferencingLiteral 3 14 will open a References browser listing all methods referencing 3 14 The following code searches for a literal string in source of all the methods of all classes Change Object allSubclasses to something more meaningful to reduce time and hits VisualAge for Smalltalk Handbook Fundamentals Smalltalk str pat methods methods OrderedCollection new str Elephant Search for this string pat Pattern new str Object allSubclasses do cls cls selectors do sel pat match cls sourceCodeAt sel index 1 notNil ifTrue methods add cls compiledMethodAt sel cls class selectors do sel pat match cls class sourceCodeAt sel index 1 notNil ifTr
203. he public interface of a part public method A method that is provided as part of the VisualAge or IBM Smalltalk API Public methods are designed to function with future releases of VisualAge or IBM Smalltalk and with operating systems supported by VisualAge or IBM Smalltalk Contrast with private method Individual application development projects can use the public and private designations as a means of organizing their code Q query specification A database query definition All queries issued to a database by VisualAge or IBM Smalltalk must be defined by a query specification quick form In the VisualAge Composition Editor a menu option that enables application developers to quickly create a default view for a part R receive To obtain and store information transmitted from a device receiver The object that receives a message Contrast with sender record 1 ISO In programming languages an aggregate that consists of data objects possibly with different attributes that usually have identifiers attached to them In some programming languages records are called structures 2 TC97 A set of data treated as a unit 3 A set of one or more related data items grouped for processing 4 In VTAM the unit of data transmission for record mode A record represents whatever amount of data the transmitting node chooses to send RecordStructure An object that contains information about the format structure
204. he user s objects and it is loaded and executed by the Smalltalk run time system In VisualAge for Smalltalk Version 3 0 single stand alone image files are the norm Typically these image files are quite large and copying and storing them requires a lot of resources because these images are not shareable code that is common between applications must be duplicated in the image files that represent each application and in memory when each application is running Although techniques have been developed to apply fixes to application programs in an image the process is time consuming and difficult especially when only a few applications classes or methods must be replaced in a large system VisualAge for Smalltalk Handbook Fundamentals In Version 4 0 ICs enable you to overcome these and other difficulties ICs promote reuse reduce memory requirements make application maintenance easier and promote porting In Version 4 0 you can divide an image into separate IC files which can be reused among independent applications ICs reduce the memory required when multiple applications are running because the ICs are shared among applications using the shared memory facilities of the underlying operating system Also ICs use a compact format which results in smaller images that load and run faster An additional benefit of the compact format is shorter time spent in garbage collection Because ICs are replaceable they make it easier to maintain
205. heme if not you could implement it yourself fairly easily using the text field modify verify callback single quote followed by a character e adds accent grave back quote followed by a character a e u adds accent aigu Shift 6 caret followed by a character a e o u adds accent circonflexe double quote followed by a character e i adds accent umlaut Accent character followed by space adds character such as space followed by c adds c cedilla The only drawback I ve found to this scheme is that if you need to type lots of quoted text it is irritating because you have to remember to type an extra space Of course the other option is to switch your keyboard to the French layout For U S users it will change most notably the location of the A Q M period comma numbers and so on The other scheme I ve seen called Transparent Language is to map the up down arrow to cycle through accented characters This is a good approach if characters are rarely entered Macintosh uses a similar scheme but uses the control key Chapter 7 National Language Support 265 Problems with National Language Support in Version 3 Question have a problem with national language support in Version 3 Why This could be a problem with the nlspath search I believe that the dynamic example does not rely on the search it expects you to tell it the exact file Are there any old nontranslated MPRs earlier in the NLS searc
206. hen inspect the partBuilder Chapter 2 General Information 33 then the subPartBuilders then the entry named Form1 in the AbtOrderedDictionary This should lead to an AbtinternalSubpartBuilder Inspect the attribute settings and then the framingSpec entry Open inspectors on the bottomEdge and rightEdge The AbtEdgeConstraint should have an offset of 0 Change it to something like 100 After closing all the inspectors save the part This requires tricking VisualAge into thinking that you have changed something so you will need to do something innocent like move the center of a connection slightly or move the updateOperation variable a pixel or two After saving exiting and reentering the part the form should now be visible allowing you to work with it The problem with the stale image may be related to the fact that the updateOperation variable is just a deferred part Deferred parts are not instances of the class they are deferring and are just a buffer for public interface attribute values Thus any behavior you may have imposed on your part to respond to a method such as image will never affect your object The solution is to add your own variable and code as though the settings page were a normal Composition Editor Passing Parameters Between Windows Tip Your VisualAge design should use the dependency mechanism For example you could have an attribute to attribute connection from a nonvisual model object attribute using
207. her To see an example do the following VisualAge for Smalltalk Handbook Fundamentals 1 From the Options menu select Add Part in the Composition Editor 2 Type in AbtRowColumnView as the class and select Part in the radio button set 3 Drop the part within your window attaching it at the top and sides to the window 4 Drop several push buttons within the row column part Use some that are graphic and some that are text just to see how it works 5 If you want a scrollable tool bar you can drop a scrolled window part from the Canvas palette and connect the workView of the scrolled window to the row column part moving the row column off to the side Creating a Tool Bar Answer What would be an easy way to create a tool bar for an application Can you simply add a menu bar to the window and have the items displayed as icons Basically what you need is a part that you can put onto a window and have the attachments made automatically to the parent This part would also have to accept buttons that are dropped onto it in edit mode and automatically make the attachments from the button to the tool bar frame To do this you could use the AbtFrameView and the AbtRowColumnView These parts are not on the palette but you can still drop them onto the Composition Editor Drop the row column into the frame view You need to open its settings and make sure that it is connected on all sides to the frame with preferably a of
208. hich you can look at the CTL files which are found in the feature subdirectory The first word in the file tells you the name of the feature as you see it in the Load Features list The rest of that first line is just information that tells VisualAge for Smalltalk under what conditions to load the feature The important information is the rest of the file It lists the configuration map versions that are loaded for the feature and the DAT file they are loaded from You can use this list to determine whether you have used a DAT file or not Manager Consistency Answer How can check my library manager for consistency so that don t end up with a badly corrupted repository where data is lost You can use the EmLibraryStatistics to check your manager for consistency To use EmLibraryStatistics read the comments in the class method checkConsistencyOfr Chapter 5 ENVY 253 Exporting a Pool Dictionary Answer Suppose define a new pool dictionary for my application How can make sure that this pool dictionary is loaded when export the application to another image There are a few methods that you will need to implement to en sure that your pool dictionaries are defined in the image prior to loading your application They are toBeLoadedCode wasRemovedCode and installToBeLoadedCode Details can be found in the BM Smalltalk User s Guide Exporting Configuration Maps Answer Vd like to export a whole bunch of con
209. high level qualifier changing name Vol2 174 CLI Vol2 120 Vol2 165 Vol2 167 connect Vol2 147 connection error Vol2 164 information Vol2 167 specification Vol2 144 status Vol2 128 via Smalltalk code conversion Vol2 137 creating table Vol2 161 current date Vol2 135 cursor Vol2 163 Vol2 167 cursor control Vol2 179 date representation Vol2 135 DB2 400 Vol2 146 DB2 6000 vol2 145 DB2 VM_ Vol2 146 DBF format Vol2 171 DDCS 2 Vol2 145 disabling error messages DLL Vol2 166 driver problem Vol2 175 error SQLO236W Vol2 188 feature installation Vol2 173 Vol2 181 fetch Vol2 148 forking process hard coded name Vol2 177 Vol2 138 Vol2 165 197 Vol2 144 database continued high level qualifier Vol2 157 Vol2 177 host variable Vol2 146 Vol2 162 host variable with wild card Vol2 140 insert Vol2 160 intercepting SQLCODE 100 Vol2 184 locked row Vol2 145 log on Vol2 148 log on prompt Vol2 128 Vol2 129 log on specification Vol2 139 manager Vol2 120 Vol2 151 maximum number of rows Vol2 153 migrating Vol2 165 migrating to CLI Vol2 168 migration Vol2 137 minimum run time files Vol2 191 missing query fields Vol2 171 name Vol2 144 object oriented Vol2 171 ODBC Vol2 148 Vol2 156 ODBC to CLI migration Vol2 168 outer join Vol2 146 override Vol2 43 portability Vol2 137 query Vol2 152 reconnecting server Vol2 120 sample Vol2 190 scrollable cursor Vol2 167 Smalltalk access Vol2 154 stored procedure Vol2 32
210. his can present an exposure if for example one of the tables contains sensitive data not included in the SQL SELECT statement Users can use interactive query tools to view the sensitive data and bypass the SELECT statement in the application program because they must have access to the entire table in order to run the SQL statement dynamically This is an even greater exposure for other SQL statements like UPDATE and DELETE Not so with static SQL User authorization may be given only to specific plans compiled SQL statements thus preventing the user from viewing or changing any data not included under the scope of the plan Static SQL is one of the strongest features of IBM s DB2 family and now VisualAge for Smalltalk allows you to exploit that strength Unified fields now allow you to create applications that are largely database neutral In Version 3 0 the database field classes which represent data types in the database are database vendor specific The DB2 field classes differ from the ODBC field classes both of which differ from those supporting native Oracle The field classes have been refactored and unified allowing you to easily switch the underlying database system without changing your Smalltalk application code The database samples have been redesigned to exploit this yielding a unified database neutral set of samples A migration tool is included that will help you convert your application from using the old database spec
211. i Is there a way to drop a bitmap BMP on a button visually Yes Use the following code Smalltalk myPushButtonView graphicsDescriptor AbtImageDescriptor new moduleName bitmap bmp 136 visualAge for Smalltalk Handbook Fundamentals Progress Indicator Window Answer would like to use a progress indicator window in my application can t seem to find a ready part for this CwWorkingDialog seems to be the base part but it does not provide the percentage completed support The EtWindow class seems to offer all support but am confused as to how to get it started What would be the recommended way for implementing a progress indicator window The following example shows how you can use the CwProgressDialog to create a progress indicator Smalltalk shell main form dialog fraction shell CwTopLevelShell createApplicationShell shell argBlock w w title Main main shell createMainWindow main argBlock w w width 400 height 300 form main createForm mainForm argBlock nil form manageChild main manageChild shell realizeWidget dialog CwProgressDialog for main dialog mwmInputMode MWMINPUTFULLAPPLICATIONMODAL dialog open fraction dialog fractionComplete lt 1 whileTrue Delay forSeconds 1 wait fraction fraction 1 10 dialog fractionComplete fraction dialog close fork Chapter 3 Graphical User I
212. ic programming foundation that carries computer messages around the globe via the Internet The suite of protocols that defines the Internet Originally designed for the UNIX operating system TCP IP software is now available for every major kind of computer operating system To be truly on the Internet your computer must have TCP IP software team programming Development of a system program or application suite by a team of two or more programmers or application developers tear off attribute An attribute that an application developer has exposed to work with as though it were a standalone part Telnet An Internet protocol that lets you connect your PC as a remote workstation to a host computer anywhere in the world and to use that computer as if you were logged on locally You often have the ability to use all of the software and capability on the host computer even if it s a huge mainframe temporary variable A variable whose scope is limited to the Smalltalk method or block in which it is defined A temporary variable takes an assigned value terminal A device that is capable of sending and receiving information over a link it is usually equipped with a keyboard and some kind of display such as a screen or a printer token ring A network with a ring topology that passes tokens from one attaching device node to another A node that is ready to send can capture a token and insert data for transmission tool bar
213. icMethods equals aFloat to delta Compare self a float with aFloat to a precision of delta Example 1502 03 equals 1051 42 to 0 01 deltah deltah delta 2 self between aFloat deltah and aFloat deltah Examples Smalitalk 1502 03 1051 42 equals 450 61 to 0 01 true 1502 03 1051 42 equals 450 61 to 0 001 true 1502 03 1051 42 equals 450 61 to 0 0000001 true 1502 03 1051 42 equals 450 61 to 100 0 true 1502 03 1051 42 equals 450 62 to 0 01 false 1502 03 1051 42 equals 450 60 to 0 01 false Chapter 4 IBM Smalltalk Programming Language 185 Smalltalk Float publicMethods printHex Answer a string which is the hexadecimal representation of a float Assumes IEEE format shifty sign exp fraction str shifty 0 8 to 1 by 1 do n shifty shifty lt lt 8 self basicAt n sign shifty bitAt 64 shifty clearBit 64 exp shifty gt gt 52 fraction shifty bitAnd 16r000FFFFFFFFFFFFF exp 0 amp fraction 0 ifTrue 0e00 str sign 0 ifTrue ifFalse exp exp 16r3FF str str 1 fraction printStringRadix 16 showRadix false str str e exp printStringRadix 16 showRadix false str Reversing Collections Answer Substrings What collections can be reversed The answer is all sequenceable collections that is Se
214. ication from one object to another that requests the receiving object to execute a method A message consists of a reference to the receiving object followed by a selector indicating the requested method and in many cases arguments to be used in executing the method There are three types of messages binary keyword and unary metaclass The specification of a class the complete description of a class s attributes behavior and implementation Every class has a metaclass of which it is the sole instance Contrast with class method Executable code that implements the logic of a particular message for a class In VisualAge methods are also called scripts See also class method instance method private method and public method MIME Multipurpose Internet Mail Extensions A set of Internet functions that extend normal e mail capabilities and enable nontext computer files to be attached to e mail Nontext files include graphics spreadsheets formatted word processor documents sound files and so on Files sent by MIME arrive at their destination as exact copies of the original so that you can send fully formatted word processing files spreadsheets graphics images and software applications to other users via simple e mail Besides email software the MIME standard is also universally used by Web servers to identify the files they are sending to Web clients in this way new file formats can be accommodated simply by updat
215. ications manager The scratch edition only exists in that user s image Using a scratch edition one can modify an application version and the existing classes contained in it without actually creating a new edition Each scratch edition has lt lt gt gt displayed around the edition timestamp or version name Contrast with edition version screen An illuminated display surface for example the display surface of a CRT or plasma panel Contrast with panel script A series of Smalltalk statements that implement an action for a part Scripts are equivalent to Smalltalk methods Script Editor A VisualAge view that enables a developer to implement part behavior by writing Smalltalk scripts methods The Script Editor shows all the objects that can be referenced by a method and all previously defined methods of a part s class selector The component of a message that specifies the requested operation There are three kinds of selectors binary keyword and unary sender An object that sends a message to another object On the level of code implementation the sender is considered to be the sending method within the class or instance that issues the message Contrast with receiver server 1 A computer that provides services to multiple users or workstations in a network for example a file server print server or mail 300 VisualAge for Smalltalk Handbook Fundamentals server 2 An object that performs one
216. icon gadgets 107 icon 108 on Windows NT 74 reusable 108 sharing 108 toggle button 105 merging applications 49 message box exit dialog 89 CPF503A Vol2 55 descriptor Vol2 74 inherited 175 misspelled Vol2 110 MQ Vol2 74 prompter labels 139 transcript logging Vol2 205 wmUser 224 method Vol2 26 Vol2 27 167 221 221 abeReinitializeDependents 24 aboutToChangeSelection 223 abrWithoutWhitespace 223 abtAddress Vol2 97 abtBuildInternals 32 Vol2 111 abtExternalizedStringBuildingInfo 263 abtPadWith upToLength onRight 223 abtScanEnv 29 213 abtScrublmage 24 25 211 216 abtShowBusyCursorWhile Vol2 18 abtSignal Vol2 70 abtWait Vol2 70 activeProcess 196 alllnstances 211 allMethodsReferencingLiteral 232 allUserTableNameslfError Vol2 170 apply 38 asDate 219 asInteger 219 asPointer Vol2 97 asTime 219 at put 222 availableSystemNames Vol2 34 avoiding standard names 46 basicAlllnstances 56 become 187 become 211 bindWith 173 blockingFactor Vol2 19 break Vol2 138 calculatelnterfaceSpec 68 calculatePartBuilder 68 closeWidget 158 Index 323 method continued method continued closeWidgetCommand 97 normalizeYear 213 commandLine 200 numberOfFrames 196 commitUnitOfWork Vol2 145 OLE generating 260 connectionInfo Vol2 167 openReadOnly Vol2 15 Vol2 19 Vol2 58 containing string 232 openReadWrite Vol2 15 Vol2 19 contextAtFrame 196 openWidget 158 convertToCodePage Vol2 76 packagerI
217. idget label openWidget VisualAge for Smalltalk Handbook Fundamentals Resizing Container Columns Questioni How can I resize container columns on the fly have resizable container columns by using the following snippet in an initialization method columnWidth is a value that calculated Smalltalk newColumns add AbtContainerDetailsColumn newPart heading columnHeading width columnWidth abtWhen cellValueRequested perform DirectedMessage new receiver self selector fillCell arguments Array with nil parentView self subpartNamed Row Container openWidget yourself This is the essence of the fillCell method Smalltalk fillCell callData Fill in cell data columnindex item columnindex callData column index columnindex is the column number item callData item item is the object associated with the row callData value item someMethod columnindex set the cell value by getting some data from the object Chapter 3 Graphical User Interface 123 Changing Scroll Bar Size Answer l am working on a touch screen only application and the scroll bars on the container details part are too small for my fat fingers Is it possible to change the size so even can use it It appears that the only way to do this is to set scrollingWithHiddenScrollBars to true on the container details view create the large push buttons with a
218. iew You can use the add API or perform the add action If you perform the action the model will signal to its views in this case the details view that an item was added The code works this way so you can add an item to the collection without having to refresh the entire list You can set the refreshEntireListOnChange attribute to true to cause the entire list to be refreshed with each addition The default for the containers is to have refreshEntireListOnChange set to false while the lists default is true Chapter 3 Graphical User Interface 127 Access to Container Object Attribute Answer What event do need to trigger from so that can have access to an attribute of an object in a container icon area If you are using Smalltalk self subpartNamed items addAll aCollection you are dealing with the ordered collection which holds the items and you are using their basic protocol That collection s protocol does not know anything about event notification which is VisualAge stuff When using the second way Smalltalk self subpartNamed performActionNamed addAll with aCollection you are dealing with a variable that contains that ordered collection It comes down to a method Smalltalk AbtObservableWrapper gt gt abtPerformActionNamed actionName ifAbsent aBlock arguments args Within that method a signalEvent whateverYourActionI s occurs Removin
219. iew and save the definition Just to be safe whenever you change the superclass of a visual part close the editor and reopen it Hover Help for Buttons 32 Questioni How do customize hover help for my push buttons Push buttons with a graphical label don t contain textual information This textual information is what is displayed by hover help and in the absence of textual information it displays the part name The part name unfortunately cannot contain special characters such as accented characters for French language When defining the push button specify both the label text and the graphics descriptor In the settings editor for the push button first define the label type as text and enter the text you want to see for hover help then define the label type as graphical and specify the bitmap you want to display VisualAge for Smalltalk Handbook Fundamentals Customizing Connection Menu Answer Can customize the connection pop up menu for a visual part Yes You must specify which options should be shown on the context menu and which can be accessed using more The preferredConnectionFeatures class method for the specific part that needs this menu adjusted must be modified as follows using a b c d as the list of connections Smalltalk preferredConnectionFeatures a b c d this shows a b c d and More on the menu Live Updating of Images Answer l am creating a settings
220. ific field classes to the new unified field classes A headless application is one that typically runs on a server and does not have a GUI or an operator console Headless application support has been added to the Version 4 0 database support so that you can package an unattended database server application that does not require a GUI ora console window Concurrency has also been added to the database support You can now develop unattended database server applications that simultaneously serve multiple clients Runtime performance of dynamic SQL applications has been improved up to 70 over the same applications running on Version 3 0 In Version 4 0 Chapter 1 What Is VisualAge for Smalltalk 19 20 many database access related computations have been moved to application development time from run time This change in Smalltalk has yielded significant performance improvements in overall database application run time Run time performance improvements of 70 in SELECT 30 in DELETE and 25 in UPDATE statements have been realized by some applications Web Connection With the Web Connection feature you can use VisualAge for Smalltalk to build applications that are accessible through the World Wide Web You use the composition editor to build dynamic Web pages that provide the user interface for your application You implement the program logic by making connections to visual and nonvisual parts and writing Smalltalk scripts just as
221. indow for an embeddable window Form Inappropriate VisualAge Icon Answer In Windows click on the VisualAge icon and nothing happens or my VisualAge icon has DOS in it instead of the eye or receive cannot run in DOS mode What should do You have probably not installed Win32s support needed for Windows or do not have the correct version of Win32s VisualAge for Smalltalk requires level 1 15 111 0 You can tell what version you have by looking at the Win32s ini file in the windows system subdirectory Refer to the readme txt file in the wradcdwi vaprodni readme subdirectory on the VisualAge for Smalltalk CD and search for Win32s instructions on installing Win32s support Double Execution of Script 70 Answer Answer Why does my script get executed twice when a user hits the enter key and use the defaultActionRequested event This is a known problem You ll need to change the method AbtTextView gt gt postCreationInitialization Locate the following piece of code in the method and remove it Smalltalk widget addCallback XmNactivateCallback receiver self selector defaultAction clientData callData clientData nil VisualAge for Smalltalk Handbook Fundamentals Error 203 Question When trying to start VisualAge for Windows get Error 203 Why Older versions of VisualAge for Smalltalk did not run on Windows 95 or NT You need to upgrade to at least version 3 0a if you want to run Visu
222. ing This means that can be redefined again to be the test for object identity The names of classes are Symbols and all the method selectors are Symbols All the lookups and the like can use object identity comparison just checking the address rather than comparing all the characters So the length of the names doesn t matter at all Instance variable names are Strings but they are used only by the compiler Once compiled the methods refer to instance variables by slot number rather than by name so the strings are not compared at run time There is obviously some size impact that may affect performance to some degree but only if there is an issue of total available memory There is an optimization in IBM Smalltalk that can fool you into thinking that part of what wrote above is wrong We would expect that Smalltalk abc abc answers true but VisualAge for Smalltalk Handbook Fundamentals Smalltalk abc abc should answer false lt answers true instead In IBM Smalltalk the compiler creates literal strings as read only objects and makes an optimization to use the same instance for any strings with the same spelling which are compiled in the same method or workspace expression To get the right answer we need to make a copy Smalltalk abc abc copy gt false but Smalltalk abc abc copy gt true Anyway trying to place any
223. ing string 223 turning notebook pages 114 turning off error message 135 type converters 220 U undefined object 69 Vol2 2 Vol2 8 unique key Vol2 46 UNIX 74 Vol2 189 Vol2 224 unloading application 56 feature 82 unspecified key Vol2 63 unused file handles 208 updating database 197 widget 191 upward compatibility 10 usenet 12 user identical 256 privilege Vol2 176 user input error 133 Index 335 user input continued type converters 220 user profile management Vol2 18 Vol2 117 Vol2 131 user profile AS 400 Vol2 54 V validating input 118 variable character field Vol2 141 global 205 references Swapper error 198 type 172 verifying security parameters Vol2 2 version identifying released 246 immutable 250 versioning application 61 view initializing wrapper removing elements 71 wrapper 89 visual part anchor block handle 135 customizing connection menu 33 inheritance 204 primary 70 printing form 152 renaming 31 reusing 140 subclass 215 synchronizing 202 window location 90 VisualAge ABTPATH 213 communications protocols 8 CompuServe 12 configuration 213 configuration management 7 CUA compliance 10 databases 8 description 1 features in version 3 13 in version 4 14 fixes Vol2 9 336 VisualAge for Smalltalk Handbook Fundamentals VisualAge continued icon 70 installed features 253 maturity 2 multiple versions 26 object repository 6 ODBC Vol2 5 openness 3 Organizer 75 packaging
224. ing the browsers list of pairs of MIME types and Glossary 293 appropriate software for handling each type See also browser client server model A nonvisual part that represents the state and behavior of a real world object such as a customer or an account Contrast with view mode name A symbolic name for a set of session characteristics For LU 6 2 a mode name and a partner LU name together define a group of parallel sessions having the same characteristics module A program unit that is discrete and identifiable with respect to compiling combining with other units and loading for example the input to or output from an assembler compiler linkage editor or executive routine monitor 1 A functional unit that observes and records selected activities for analysis within a data processing system Possible uses are to show significant departures from the norm or to determine levels of utilization of particular functional units 2 Software or hardware that observes supervises controls or verifies operations of a system Multiple Virtual Storage MVS An IBM licensed program whose full name is the Operating System Virtual Storage OS VS with Multiple Virtual Storage System Product for System 370 It is a software operating system controlling the execution of programs multireceive dialog A dialog that takes one data record from the object that initiates the dialog sends it to a remote program and ret
225. ing the packager to include the selector class and so on from the application no matter whether the packager thinks it should be included or not However you still need to tell the packager what application to draw from Class Modifications and Packaging Answer Suppose you extend a class such that you need to create a new edition of the application to which that class belongs will there be anything special you need to do when you package your application No if you have your changes loaded in the image when you package then the changes will be picked up by the packager For what it is worth if you extend a class you only add methods and do not directly modify the existing code so you should not have to modify the owning application You can create a new extention of that class in your own application by selecting New Extension from the Parts menu in the Organizer Merging Application Files into Run time Image Questioni The VisualAge 3 0 on line manuals state that it is possible to merge APP files into run time images even if the image is not the stock image but a reduced one How do enable the reduced image to load the APP files Chapter 2 General Information 49 Answer A stock image is no longer shipped since Version 3 You can either generate it using the Packaged Images Browser and appropriate packaging specification AbtEaRuntimeSpecification and use the ABTAPP CNF approach as with Version 2 or you must add
226. ion in place of application program application program interface API An architected functional interface supplied by an operating system or other software system The interface enables an application program written in a high level language to use specific data or functions of the underlying system application programmer A person who primarily writes and modifies programs for application data Contrast with system programmer Archie An Internet tool for finding files stored on anonymous FTP sites You need to know the exact file name or a substring of it architecture A logical structure that encompasses operating principles including services functions and protocols argument A data element included as part of a message Arguments provide additional information that the receiver can use to perform the requested operation Binary messages and keyword messages take arguments Ina keyword message a colon following a keyword indicates that an argument is required ARPANet Advanced Research Projects Agency Network the precursor to the nternet Developed in the late 1960s and early 1970s by the US Department of Defense as an experiment in wide area networking that would survive a nuclear war See also Internet array literal A literal that is an indexed sequence of literals The symbol precedes this sequence and parentheses enclose the sequence For example 5 7 9 is an array of three integers ASCII
227. ions of how input data is to be presented to a program from internal storage and how output data is to be presented to internal storage from a program The collection of all database files makes up the database all the data files stored in the system database manager A VisualAge or IBM Smalltalk database component that models a database management system in order to provide the interface between an application and the database management system data description specifications DDS A format for describing the user s database files or device files to the system Describing a file in DDS is similar to filling in information on a form that is arranged in columns and rows The most common characteristics such as the names and lengths of fields are described by putting entries in specific columns on the form Another part of the form allows special parameters that describe less common and more varied characteristics The finished specifications are then used as the source for creating the file data integrity 1 The condition that exists as long as accidental or intentional destruction alteration or loss of data does not occur 2 Preservation of data for its intended use data processing The systematic performance of operations upon data for example handling merging sorting and computing data queue A way to communicate and put data used by several programs in a job or between jobs The data queue is identified to
228. iskFreeSpace C IpSectorsPerCluster sectorsPerCluster IpBytesPerSector bytesPerSector IpFreeClusters freeClusters IpClusters totalClusters freeSpace sectorsPerCluster abtAsInteger bytesPerSector abtAsInteger freeClusters abtAsInteger CwMessagePrompter message Free space on disk C is freeSpace printString 262 VisualAge for Smalltalk Handbook Fundamentals Chapter 7 National Language Support In this chapter we cover questions related to national language support of VisualAge for Smalltalk Code Page Support Questioni Does VisualAge for Smalltalk support my particular code page VisualAge for Smalltalk makes an operating system call to translate the string If the operating system call doesn t support the conversion between the code pages then it will try to translate with the translate tables you provide The operating system calls are different for each platform To see if the call is supported on your machine take any string and pass the message convertToCodePage Smalltalk Hello World convertToCodePage 37 where the number passed is the code page you wish to convert to If the code page is not supported the method convertToCodePage will return an AbtError with errorText set to Conversion from codepage lt gt to codepage lt gt is not supported Code Page and MPR Problems Tip The code page is stored in the MPR file so it can be
229. its public interface to the list in the first GUI window The second window could have a variable promoted to its public interface that receives the model object from the first window It is this object that is receiving the edits in the second window When the changes occur as when an OK button is clicked the model object state changes and its dependents are notified including those in the first window The refresh will then occur after the changes to the model object state Generating Archival Code Question What application should you specify when generating archival code 34 VisualAge for Smalltalk Handbook Fundamentals Create a new application such as MyArchivalApplication and generate Answer i archival code to it You don t want to generate archival code to the application that you plan to package and distribute to your customers it will be larger than it needs to be You can always delete the generated methods if necessary To create your archival application do the following 1 From an application manager create the archival application Change its prerequisites to include AbtBuildViewsApp plus the application you are generating code for 2 Open the part in the Composition Editor or Public Interface Editor 3 Select Generate archival code from the File pull down menu 4 Select your archive application s name as the target for the generated code Note We recommend a one to one corresponden
230. ixed size and one had to know ahead of time how big a table to allocate Further each object reference was indirect through the table calculate the table address given the index and then fetch the real pointer to the object So what to do Without an object table doing a full fledged become requires scanning all objects in the world to find pointers to other objects and changing the affected pointers each place they are found What was a few microseconds suddenly became several seconds Not good So two schools of wizards developed One school forbade symmetric become entirely All become had to be asymmetric with the second object simply replacing the first While this still required scanning the world it was faster than the work required to to a full symmetric become Chapter 4 IBM Smalltalk Programming Language 187 The second school felt that become was too important to go away They made all object pointers indirect not through an object table but through a hidden pointer While this took more memory and made object references slower than the other wizard s solution it was better than using an object table But which wizard is which One can often tell a wizard by the spells they use In Smalltalk running some timing code often lets one deduce which spell was used Below are tests of the three implementations have handy IBM Smalltalk V3 on a 486 under Warp VisualWorks 2 0 on a Mac Quadra 950 68040 and Digitalk S
231. job description Vol2 12 job queue Vol2 59 library list Vol2 57 migrating Vol2 27 multiple connections Vol2 10 multitasking Vol2 15 native application Vol2 8 ODBC default library Vol2 45 ODBC requirements Vol2 6 OfficeVision 400 Vol2 50 opening and closing file Vol2 43 packaging application Vol2 8 Vol2 21 Vol2 22 password Vol2 18 Personal Communications Vol2 37 physical file member Vol2 11 record class Vol2 3 record description Vol2 31 Vol2 35 reestablishing connection Vol2 56 referential integrity Vol2 55 repeating record structures Vol2 37 RPC Vol2 1 RPC message Vol2 51 Rumba Vol2 10 runtime prerequisites Vol2 9 screen scraping Vol2 24 AS 400 continued service program Vol2 24 sign on Vol2 2 sign on dialog Vol2 17 sign on screen Vol2 44 simultaneous DDM access Vol2 39 SQL Vol2 11 stored procedure Vol2 32 synchronizing VisualAge application Vol2 8 transaction program Vol2 23 user ID Vol2 18 user profile Vol2 54 using Windows 3 1 Vol2 62 work station function Vol2 10 ASCII EBCDIC conversion Vol2 75 reporting in file Vol2 232 work station controller Vol2 4 association pool dictionary 193 asynchronous job Vol2 12 atom 168 attribute changed event 213 cursorPosition Vol2 79 lastError Vol2 72 promptForUserldAndPassword Vol2 17 resultlsReady Vol2 1 selectionlsValid 156 synchronizing 45 tabContents 115 updating class 205 audio cards 85 automatic log off 202 tab moving 132 tabbing 132 162 AVA playback 85 ba
232. k There is a method available to strings that will allow you to scan the environment variables for the path indicated It is called abtScanEnv For the ABTPATH value you can evaluate Smalltalk abtpath abtScanEnv Note This method is private and really shouldn t be used However there is no other way to do this Double Triggering of Changed Events Questioni How do make events work for Smalltalk Classes When VisualAge was originally created it was intended that Smalltalk classes from other environments could be ported directly To accommodate such an ability the development staff included some code that automatically triggers the feature connections of a part whenever an attribute changes or an action is performed presumably in either case the attributes of a part might change One symptom of this problem is the triggering of attribute changed events twice whenever any attribute changes or an action is performed The signalEvent with code in the setter method for an attribute triggers the event and the special code automatically triggers the event a second time Besides being a little inefficient this has the added problem of signaling all events automatically for us regardless of the code executed To handle all events explicitly the automatic mechanism can be turned off by overriding the following instance methods for each Smalltalk class Chapter 4 IBM Smalltalk Programming Language 213
233. k mouse clicks and movements over a bitmap For your application you might put hot spot parts on the bitmap 140 VisualAge for Smalltalk Handbook Fundamentals Setting Help Answer How do programatically set the help file and help topic IDs for the menu items assume you want to use a symbolic name that will be mapped to an actual name at execution time This is handy for dealing with files whose names include version information For example ABTVAE30 082 contains such a mapping entry The entry abtvahelp is the symbolic entry we use in the settings view as the help file name It is mapped to an actual file name of ABTVAE30 at execution time When we updated the file for Version 4 to ABTVAE40 we simply updated the one entry in the mapping file and did not have to touch any code The entries in a given mapping file do not support automatic substitution The design is such that the name of the mapping file can vary by platform for example ABTVAE30 082 is the English version while ABTVAJ30 0S2 would be Japanese and these mapping files would map the symbolic name to the appropriate locale specific name Your application would then register the mapping file with the locale character as a wild card You can see an example of this in the method AbtEditBaseApp class gt gt loaded Create locale specific versions of the mapping file where within each mapping file a consistent symbolic name maps to the locale specific actual absolute
234. k sourceModel itemsDropped aCallback sourceltems itemsDropped isEmpty ifTrue nil index items indexOf itemsDropped first position aCallback event y aCallback offsets first y negated itemsDropped do item items remove item ifAbsent index lt position ifTrue position position 1 position gt items size ifTrue position items size items addAll itemsDropped afterIndex position aCallback sourceWidget userData items items The example works for a list and for a multiselect list Chapter 3 Graphical User Interface 111 List Box Behavior Answer When the focus is on the list box part and the user clicks on a character key the list box should scroll to the first item begining with this character When typing another character the list box should scroll to the next item that starts with the character that was typed first followed by the character that was typed second Is it possible to get this behavior from the list box parts and if so how On OS 2 and Windows pressing a character scrolls to the list box entry that starts with that character You might override this behavior by creating a form around the list box and using CwComposite gt gt interceptEvents to trap the events going to the list box But an easier solution and one you see see many times is to add a Search entry field above the list box and scroll the list box with CwList gt gt topltemPosition
235. k tab nextPutAll No cat files needed ifFalse catFiles asSortedCollection do each work tab nextPutAll each cr work cr nextPutAll Mpr files cr mprFiles isEmpty ifTrue work tab nextPutAll No mpr files needed ifFalse mprFiles asSortedCollection do each work tab nextPutAll each cr Format Change for CTLs Tip The format of the CTL files used during feature load and unload has changed between Version 3 and Version 4 This change will affect you if you create CTL files for your components Sample V3 CTL File Format Smalltalk SOMsupport AbtCommonProductInstallerApp products va platforms aix os2 win95 winnt sys es SOMsupport V 3 0a abtesm30 dat AbtSOMsupport V 3 0a abttsm30 dat Sample V4 CTL File Format 80 VisualAge for Smalltalk Handbook Fundamentals Smalltalk SOMsupport Base AbtCommonProductInstallerApp productld sdcs00000023 platforms win95 winnt os2 unix include abttvv40 ctl include abtesm40 ctl AbtSOMsupport Run ts 3032438045 abttsm40 dat AbtSOMsupport Run V4 0 AbtSOMsupport Edit ts 3032437984 abttsm40 dat AbtSOMsupport Edit V4 0 Here is what has changed e Feature identification Text up to the first double quote forms the feature name that will display in the Feature load and
236. ker Vol2 42 parameters Vol2 157 PC Support Vol2 48 requirements Vol2 7 SQLSTATE 37000 Vol2 123 SQLSTATE 81010 vVol2 124 stored procedure Vol2 32 Vol2 193 text driver Vol2 132 TopLink Vol2 118 ODBC INI Vol2 45 ODBCADM Vol2 134 OfficeVision 400 Vol2 50 OLE class generator 260 client 260 generating methods 260 sharing objects 260 open database connectivity See ODBC opening inspector 38 multimedia device 84 window centered 93 window maximized 92 openness VisualAge 3 operating system registering event 225 optimized 32 bit client Vol2 7 Oracle blocking Vol2 172 break API Vol2 138 connection Vol2 122 data types Vol2 130 DLL Vol2 122 driver Vol2 175 error 126 Vol2 122 error ORA 00942 Vol2 177 organizer preferences 75 views 42 0S 2 AS 400 access through CM 2 Vol2 4 calling image from Vol2 91 calling PM API functions Vol2 88 code page conversion 266 distributing application 252 drag and drop 129 event handler 151 LAN Server Vol2 7 LIBPATH Vol2 83 maximize window 91 memory leak Vol2 96 MQ Vol2 79 MQSeries Vol2 75 multithreading 204 notebook 116 117 ODBC Vol2 134 optimized client Vol2 21 PM API Vol2 88 session manager Vol2 84 shutdown 43 SOM object Vol2 246 swap file Vol2 96 task list 131 thread vol2 143 Warp client 84 workplace shell Vol2 247 OS 400 host servers Vol2 23 host services Vol2 12 Index 327 outer join Vol2 146 OV 400 Vol2 50 overlapping fields
237. l Features Several Version 3 0 optional features have been moved into the base including native Oracle support Connection for Lotus Notes Reports two of the tools from the Distributed feature and Pro Server providing the best value in the industry Management of applications is improved by including Tivoli Connection parts in the base that enable your application to interact with the Tivoli system management products The two tools from the Distributed feature that are now included in the base enable you to analyze your application s performance The Object Visualizer helps you analyze object activity and interaction in your application You can see how many instances of a class exist at any time watch a visual representation of message traffic between objects identify which objects are most and least busy and determine which clusters of objects should be local to each other based on the amount of message traffic between them The cluster view dynamically displays the objects and clusters as they form and re form so you can see graphically the cohesion between your objects The Event Profiler is a browser that shows all of the events method calls sent among selected objects You can use it to browse each event and trace the method call stack that led up to it Using these tools you can better understand the message traffic and interaction between the objects in your application and then tune your application for peak performance IBM
238. l2 122 passing complex structure Vol2 98 source breakpoint Vol2 86 unable to replace Vol2 83 document OfficeVision 400 Vol2 50 double byte character set 267 double triggering of event 213 drag and drop list box 110 drag and drop link 138 on push button 144 porting 129 DRDA vol2 5 driver audio 85 dBase Vol2 128 Jet Vol2 127 Microsoft Access Vol2 123 ODBC Vol2 123 ODBC license Vol2 191 text Vol2 132 DSOM accessing object Vol2 241 daemon Vol2 240 DSOM continued ending VisualAge Vol2 241 hanging system Vol2 239 synchronous call Vol2 240 dynamic menu 105 107 push button 160 where clause Vol2 125 Vol2 147 dynamic link library See DDL E EBCDIC ASCII conversion Vol2 75 ECI Vol2 72 edition date stamp 247 loading previous 249 reloading current 249 timestamp 247 EHLLAPI Vol2 21 Vol2 80 EMSRV_ 47 82 84 252 256 emulation 5250 Vol2 21 encapsulation 65 environment variable 29 Vol2 241 ENVY 2 4 7 243 ENVY 400 Vol2 49 ENVY Manager 257 EPI Vol2 115 equality 184 221 226 240 error 126 connecting to Oracle Vol2 122 30081n Vol2 120 Abt 154e Vol2 83 ABT SQL 9 w Vol2 152 AS 400 communication Vol2 2 attribute does not exist 129 block Vol2 142 bypassing prompter Vol2 142 catching 179 catching all 181 228 CfsError Vol2 8 client not authorized Vol2 214 code 1 Vol2 124 database connection Vol2 164 disabling message Vol2 165 error continued distributed load Vol2 201 file in use
239. lash screen e If you do want the VisualAge splash screen leave the rest as is Once you have saved the changes to your abt rc compile your resource script file and merge this into your abt exe or nodialog exe with the following command rc abt rc abt exe or rc abt rc nodialog exe You can find a resource compiler in the OS 2 toolkit Once this is done you can run your application against your image Infinite Loop How do find a way out of an infinite loop Does VisualAge have something like CTRL C Chapter 2 General Information 27 Answer VisualAge allows you to hit Alt SysReq Hold this until you hear a low Answer i beep A debugger will appear signaling that the process has been terminated or interrupted with the error string User Break File In and File Out Questioni How do file in and file out code programmatically You can write Smalltalk scripts that will file out code for you Doing this you can make the scripts as sophisticated as you want Use class CfsWriteFileStream to create your file Examine the class EmFileOutInterface This class has several methods which you will find useful such as fileOutOn fileOutSourceOn from and so on Do not forget to generate archival code when you save the part Separate Threads Questioni Can I run VisualAge for Smalltalk from separate operating system threads True multithreading has been tested in AIX but no specific release plans are availab
240. lass or a subset of a class They are also used to select some instances of one specific class based on some criteria Use Manager as suffix Category Naming How should group methods within a class in order to improve readability Category names have to be explicitly created We propose category names for instance and class methods Questioni Categories for Instance Methods Get and set selectors Answer Answer Contains all accessor methods for instance variables e Extensions Used when an extension is made to an existing class of the development tool e Initializations Contains initialization methods e User interface logic Used for validation or navigation logic 4 VisualAge and Transaction Processing in a Client Server Environment Andreas Bitterer et al Prentice Hall PTR 5 Enhancing the Object Design Process Using Stereotypes paper presented by Rebecca Wirfs Brock at the Smalltalk User s Conference in New York 1996 66 VisualAge for Smalltalk Handbook Fundamentals ResponsibilityName A category is created for each responsibility for example contract taken by the object Services Contains methods having a general purpose such as boolean or copy methods We do not recommend defining a method to more than one category even if the tool allows it Categories for Class Methods Some categories for class methods are the same as those described for instance methods Get and set selectors Cont
241. lasses interface 1 A shared boundary between two functional units defined by functional characteristics common physical interconnection characteristics signal characteristics and other characteristics as appropriate 2 A shared boundary An interface may be a hardware component to link two devices or a portion of storage or registers accessed by two or more computer programs 3 Hardware software or both that links systems programs or devices interface aids In VisualAge when used together with the RecordStructure classes the interface aids convert existing C or COBOL definitions into Smalltalk objects Internet The vast collection of interconnected networks that all use the TCP IP protocols and that evolved from the ARPANET of the late 1960 s and early 1970 s By July of 1995 the Internet was connecting roughly 60 000 independent networks into a vast global net intranet A private network inside a company or organization that uses the same kinds of software that you would find on the public Internet but that is only for internal use As the Internet has become more popular many of the tools used on the Internet are being used in private networks for example many companies have Web servers that are available only to employees IP Internet Protocol The rules that provide basic Internet functions See TCP IP IP Number An Internet address that is a unique number consisting of four parts separated b
242. ld be along the lines Smalltalk keyPressed aWidget clientData clientData callData callData callData isShiftPressed and callData keysym XKF10 ifTrue This assumes you can see the pool dictionary CwConstants in your class Changing Object Class Question Does IBM Smalltalk provide a way to change the class of an object something equivalent to ObjectWork s changClassToThatOf There is an undocumented primitive to do this but you have to write your own method Try something like this Smalltalk Object gt gt changeToClass aBehavior Change the Class of the receiver to aBehavior Note does not verify compatible class shape lt primitive VMprObjectClassColon gt self primitiveFailed Chapter 4 IBM Smalltalk Programming Language 231 Cleaning Up the Image Answer During development my image has grown far too big Is there an easy way for me to clean up the image The image has probably grown for two reasons 1 You have loaded a lot of applications in it or 2 You have a lot of instances alive in it would first consider unloading applications you are not working with or starting with a clean image the one you originally started from and loading only the applications you need In the second case if you know the class of the instances that are bothering you you could try Smalltalk aClass alllnstances do i i becomes nil That would free t
243. le OS 2 and Windows releases do not support true multithreading OS 2 and Win95 NT may support multithreading in a future release but have been unable to find out specifics so far The only ways to do parallel processing today are e Launch multiple copies of VisualAge for Smalltalk on the same or different machines e Use the VisualAge Distributed feature along with launching multiple copies Distributed would be much easier to coordinate and is quite elegant but does require a larger image and adds complexities such as TCP IP setup if you don t already have it Capturing Stack Information Question How can capture the stack information when have a walkback 28 VisualAge for Smalltalk Handbook Fundamentals Answer In the debugger window use the Write Stack Trace Text To File option from Answer f R the Stack pull down This writes the information to a file of your choice Renaming a Class Question How do I rename a class The VisualAge for Smalltalk User s Guide discusses this a little bit Filing out and filing in classes to rename them works fine Another way to rename classes is this Change to the Script Editor for the class Change the class name in the class definition in the bottom window of the Script Editor to the desired name Save the change A new class with the desired name will be added to the application browser It is an empty class for now Select all methods showing in your me
244. le In Use error when trying to read only a file in VisualAge Normally this is caused by an access rights problem outside the VisualAge domain Make sure the server access allows concurrent read only rights to clients Check this out by making sure you can see the files and file contents from any program on the client system In VisualAge make sure the code uses the ORDONLY access mode Do not use any of the following OWRONLY ORDWR OCREAT OAPPEND OTRUNC or OEXCL OS 2 Shutdown Answer Why doesn t OS 2 shut down until all running applications have terminated In general OS 2 won t shut down until all running applications have terminated to prevent the user from possibly losing data This is an OS 2 behavior for any application and is not unique to VisualAge BRW Format Generator Answer Is there a generator that produces a BRW format for help Use an ASCII editor or Smalltalk Workspace to develop a BRW file We gave the source files the extension BRW for browser to distinguish the files from other types of files The BROWSER BRW file describes the tags used to specify fonts lay out a page display a graphic and so on To see how we used the tags open an ASCII editor on BROWSER BRW or VAXAMPLS BRW To see the formatted text or view your own file test AbtHelpBrowserView and load the file AbtExamplesHelpBrowserSubApp contains the Smalltalk code that parses the tags We ll probably change our code so it
245. le is Never compare Floats for equality e It is impossible in general to precisely convert decimal numbers to binary and floats are binary Thus most numbers are wrong as soon as they are converted Multiplying them by 100 0 may make a particular calculation look right but just shift the problem to another calculation e Certain operations can cause the loss of precision One famous gotcha involves subtracting two floats that are nearly equal The precision of the result may be only a digit or two or even none at all To see what is actually going on used some code that prints floating point numbers to any length also coded a method which prints IEEE double precision floats in hexadecimal The method is near the end The exponents in hexadecimal are the number of bits to shift the fraction Lets look at some examples First just some plain numbers Smalltalk 0 00 printHex 0e00 1 00 printHex 1 0e0 10 0 printHex 1 4000000000000e3 16 0 printHex 1 0e4 Now the numbers from the thread and one number that s 0 01 larger Smalltalk 1502 03 printHex 1 7781EB851EB85eA 1502 04 printHex 1 77828F5C28F5CeA Note difference in fifth digit 1051 42 printHex 1 6DAE147AE148eA The printStringWidth method prints numbers to the given character width The width used here is 30 which means 28 digits less period and sign As a result it may show junk past the end of the number In the cas
246. le or any other support that helps with the rounding issues encountered with floating decimals If you are stuck with a Smalltalk without fixed decimal don t forget that Smalltalk fractions are true fractions so 10075 100 is a true representation of 100 75 although it will print as 403 4 Also Decimal class is part of the base product in Version 3 Object Class Identification Question How can programmatically see if anObject belongs to aClass This is actually two separate questions Object gt gt isKindOf aClass answers a Boolean which is true if aClass is the class or a superclass of the receiver and false otherwise Object gt gt isMemberOf aClass answers a Boolean which is true if aClass is the class of the receiver and false otherwise Floating Point Numbers Question believe there is much oddity with the behavior of floating point numbers e 534 92 100 is displayed as 53492 0 e 53492 0 truncated is displayed as 53492 e 534 92 100 truncated is displayed as 53491 Is this as bug 182 visualAge for Smalltalk Handbook Fundamentals Answer This is not a bug No matter how odd they look floats are precisely what Answer el shee K ia scientific and engineering problems need Those oddities were carefully and specifically designed Floating point numbers are designed for use in the engineering and scientific communities where calculations involve wide ranges of number sizes e One basic ru
247. learing the dependencies terminating processes and so on If it does not then you probably have a reference either in class or class instance variables or a reference in the Smalltalk dictionary itself An object is garbage collected when there are no references to it that ultimately references something in the global or old space There are two types of garbage collections flips and sweeps A flip is lightweight if an object is referenced by anyone it is included in the flip called a flip because objects are flipped between two areas of memory A sweep is more costly because it starts in the old space and traces references to the end Sweeps take 5 10 seconds on my machine but rarely occur The goal is to maximize the recovery of objects in flips and minimize the sweeps It is helpful to eliminate old space types of references such as globals and class variables and to avoid communes circular references Objects that survive several flips are tenured to old space under the assumption that they re going to be around for a long time and it is a waste to keep copying flipping them In Version 3 there are command line options to change or limit the size of the various spaces Chapter 4 IBM Smalltalk Programming Language 211 4 Digit Years Answer Evaluating the expression Date today yields 04 01 96 What want it to yield is 04 01 1996 Is there a way can achieve this With VisualAge you can do this by specifying i
248. lication rather than having a separate archival application which is strongly recommended If this is the case you should create the separate archival application move all archival code into that application and update your prerequisites so that they do not include any of the development time applications To determine which methods are archival just regenerate again and note the messages in the Transcript An API document is shipped in softcopy form with the product which details what applications are considered part of the runtime and thus redistributable Generating Getters and Setters Tip You can use the TrailBlazer browser to generate getters and setters for an application Select a class navigate to instance variables or class variables select a variable pop up the menu and select Generate Accessors High Performance Trace Logging 54 Tip For complex systems often trace logging must be built in Unfortunately you can incur a high performance penalty if you do not build in trace logging properly One way of avoiding this penalty is to send blocks rather than strings to your logging subsystem For example VisualAge for Smalltalk Handbook Fundamentals Smalltalk self traceShow l am entering method blah for self printString with myArg printString Using a string can be expensive because you have to build the entire string even if tracing is not active Therefore use a bl
249. llback collapseCallback receiver self selector collapseNode clientData callData clientData nil You would then need to implement the expandNode clientData callData and collapseNode clientData callData selectors in your parts to handle the registered events See the IBM Smalltalk Programmers Reference for more information about callbacks Deactivation of OLE Embedded WordPro Document Tip An unhandled exception occurs when deactivating an embedded in place activated OLE client container that contains a Lotus WordPro document To work around this problem when using WordPro documents specify an activationPolicy of XmOPEN in the OLE Client part to disable in place activation Copying from Windows Explorer into an OLE Client Part Tip Use copy and paste to share OLE objects between the Windows Explorer and an OLE Client part Dropping an OLE object that was dragged from the Windows Explorer onto an OLE Client part does not work Generating OLE Methods 260 Tip The OLE Class Generator generates set methods that signal the wrong event name For example the generated name of the change symbol for the attribute count is countChanged However the generated count setter method contains the following code VisualAge for Smalltalk Handbook Fundamentals Smalltalk self signalEvent count with aValue The signalEvent code will have no effect because the change symbol for the does not mat
250. llections often hang on to a sort block this may be a source of trouble Chapter 4 IBM Smalltalk Programming Language 217 Smalltalk objects dumper totalBytes objects OrderedCollection new 100 timesRepeat objects add String new 48 1024 atAllPut x yourself objects do ea ea at 40 1024 put dumper ObjectDumper new totalBytes dumper totalSizeBeforeUnload objects System message total bytes in persistend object totalBytes printString dumper unload objects intoFile foo obj objects ObjectLoader new loadFromFile foo obj objects do ea ea at 40 1024 ifFalse self error bad obj System message Everything went fine Collections and do 218 Answer was trying to find out how the method do works when send it to an ordered collection found out that AdditiveSequentiableCollection has the instance variable implementationCollection and the method do This method probably uses do from SequencableCollection Where does implementationCollection get initialized and to what Collections in IBM Smalltalk aren t the same as the collections in other Smalltalk implementations That is their public protocol is the same but the implementation has been significantly optimized The implementation changes depending on the size of the collection The implementationCollection variable is the reference to t
251. lltalk widget class see CwBasicWidget class gt gt widgetFor As a result you can map only one Motif widget class into a single Smalltalk class Note Multiple Motif widget classes can be handled by the same Copyright IBM Corp 1997 87 Smalltalk class Several classes do that see implementors of platformWidgetClass One possible particular scenario is You create a subclass of CwPushButton and when the class initialize method is run CwBasicWidget the CwWidgetClassMappings table is rebuilt This causes all Motif push button widget class instances an address to be mapped into the new subclass The new CwPushButton subclass could add platformWidgetClass and platformWidgetGadget methods to make them unique not inherit from CwPushButton although don t know what address they could specify since it is truly a Motif push button Despite all this verbose explanation cannot explain why this particular walkback occurs but argue it is largely academic because even if there wasn t a walkback simple subclassing of a CwBasicWidget would not work Instead subclass a CwExtendedWidget where the primary widget is a push button Motif Documentation Answer Is there any formal documentation as to which Xm entries are available VisualAge for Smalltalk does not use any application specific X resources but it does inherit the standard Motif Xt X11 resources by virtue of being an X client and using the native widgets F
252. location 55 General Protection Fault invalid instruction executed If the primitive error is associated with a callWith type method then the general production fault occurred in the DLL being called or in a function that it called If the primitive error is associated with a xxxAt or xxxAt put type method then an invalid address was supplied to the method Error Does Not Understand Format Question After filing in code from Version 2 Standard to Version 3 Team get a debugger with AbtlbmDate384Field does not understand format when generating runtime code for an access set Chapter 2 General Information 73 Answer Implement a format instance method for AbtlomDate383Field that does nothing Menu on Windows NT 4 0 Answer VisualAge for Smalltalk Version 3 0a for Windows has a small menu problem when run on Windows NT 4 0 The context menu for text fields appears after a default windows menu What do do This behavior can be easily fixed by executing the following code Smalltalk OSWidget eventTableAt 16r7B WmContextmenu put wmContextmenu with Back tabbing in Container Details Views 74 On some UNIX platforms HP UX and Hummingbird Exceed X server for example shift Tab is mapped to key symbols other than back tab The container details view expects shift Tab to back tab or tab to the left Therefore when running VisualAge on these platforms you may need the following
253. ls on the AbtMessagePrompter part You can t because AbtMessagePrompter uses CwMessagePrompter which uses the native operating system API for example WinMessageBox under OS 2 and that doesn t support button string substitution suggest creating your own view with your message then displaying it as a dialog such as 160 VisualAge for Smalltalk Handbook Fundamentals Smalltalk myView openApplicationModalWidget suspendExecutionUntilRemoved myView result ifTrue The result method is implemented by your view and is the result of the user s selection probably saved in an instance variable Adding BMP Files to Buttons Questioni Does VisualAge support putting BMP files directly onto buttons Yes since VisualAge for Smalltalk Version 3 Good bye one DLL hello dozens of BMP files Use the following code Smalltalk myPushButtonView graphicsDescriptor AbtImageDescriptor new moduleName bitmap bmp Creating a Prompter Questioni How do create my own prompter for a GUI Add an instance variable result to your view and implement a prompt method Smalltalk prompt result nil self suspendExecutionUntilRemoved result You would open the view like this Smalltalk view MyView new openApplicationModalWidget myResult view prompt Chapter 3 Graphical User Interface 161 Setting Focus to Next Entry Field Question How can automatically move th
254. luding main storage input output devices the processing unit data sets and control or processing programs 2 In the NetView program any hardware or software that provides function to the network response A service primitive issued by a service user to complete the procedures associated with a confirmed service return code 1 A value usually hexadecimal provided by an adapter or a program to indicate the result of an action command or operation 2 A code used to influence the execution of succeeding instructions return value An object or data type that a receiver object passes to a sender object in response to a message router A network device that enables the network to reroute messages it receives that are intended for other networks The network with the router receives the message and sends it on its way exactly as received In normal operations they do not store any of the messages that they pass through routine Part of a program or a sequence of instructions called by a program that may have some general or frequent use Glossary 299 RPG A programming language designed for writing application programs for business data processing requirements The application programs range from report writing and inquiry programs to applications such as payroll order entry and production planning S scratch edition A mutable and private copy of an application for a user who is not necessarily the appl
255. ly matter that they re the same object For example if you try this code snippet the results will be what you expected Chapter 4 IBM Smalltalk Programming Language 221 Smalltalk ab a 9 printString b 9 printString a b gt true a b gt false Replacing Character in String Answer In some other Smalltalk implementations can replace characters in a String by using the method Smalltalk String gt gt at put In VisualAge if I try the following Smalltalk dog at 1 put D get a walkback with the following error Store into read only object What is happening And what is the right approach for replacing characters in a string In your case dog is a literal Some other examples of literals are 3 14 D101 and 1234 You should never try and replace characters in a literal string This is one of the most common sources of errors in other Smalltalk platforms IBM solves this problem by preventing it altogether If you want to do this make a copy of the string first like this Smalltalk dog copy at 1 put D 222 VisualAge for Smalltalk Handbook Fundamentals Padding Strings Question Is there a method that allows me to pad a string with n number of characters to the left or right EsString gt gt abtPadWith upToLength onRight is the method you are looking for Here are a couple of examples of how the method works
256. malltalk V Mac on the same Quadra ran some tests First is the become test Smalltalk System globalGarbageCollect Time millisecondsToRun 1000 timesRepeat ab a asdf copy b t a a become qwer copy a b ifFalse self error Whoops b It creates an object assigns it to two variables so to speak and then does a become with a similar object When done it tests to see if the two objects have the same value If not something went astray It answers b which has the same value as a Select the innermost block contents and do evaluate it A similar test uses assignment instead Smalltalk Time millisecondsToRun 1000 timesRepeat ab a asdf copy i a qwer copy b ifTrue self error Whoops J ooo 188 VisualAge for Smalltalk Handbook Fundamentals Since it uses assignment b is unchanged and the test is reversed If an implementation has an object table or uses pointer indirection one would expect the two methods to run with very similar timings If it has no object table but has to search the world the two should be very different When timing the tests on IBM Smalltalk Version 3 had the following results 6230 6232 6220 6264 The results without globalGarbageCollect were 13417 12105 10348 14050 3355 Then used the second method with the results being 66 69 66 The ratio is roughly 6200 66 or roughly 100 1
257. map freePixmap Display the cursor window defineCursor cursor Delay forSeconds 5 wait window undefineCursor cursor freeCursor gc freeGC VisualAge for Smalltalk Handbook Fundamentals Animated Busy Cursor Answer How can display an animated busy cursor similar to the activity indicator on the print preview know can use the System showBusyCursorWhile method that displays the system clock but sometimes the users may think the system is locked Check out the spinning clock in the VisualAge for Smalltalk Help Examples for an example of how to make an animated progress indicator Adding Pull Down Menu Choices Dynamically Listed below is some sample code that you can use to dynamically add pull down menu choices You will need to add a callback method to do some processing when the user clicks the new pull down choice Smalltalk addMenuChoice Dynamically add a new menu choice to a menu newMenuChoice newMenuChoice self subpartNamed Menu1 widget createPushButton New Choice argBlock nil newMenuChoice addCallback XmNactivateCallback receiver self selector newChoicePushed clientData callData clientData nil newMenuChoice manageChild Toggle Buttons in Menu Question want to have a menu with toggle buttons Sort by Date and Sort by Name and possibly some other sort criteria want to have a check mark in one of these buttons only tried to c
258. message box 89 modal 94 nonmodal 142 sign on Vol2 17 dictionary dependent 96 global 173 global variable 205 lookup 193 versus lookup table 234 digital video player 84 directory contents 176 disabling close option 97 methods 56 mouse pointer 101 notebook tab 125 push button 106 156 disk space 233 261 display retreiving resolution 92 distributed activation Vol2 199 adding client Vol2 209 client run time access Vol2 218 DBCS Vol2 223 debugging client Vol2 219 handling TCP IP addresses Vol2 213 headless server Vol2 200 initialization Vol2 202 loading feature Vol2 217 modifying server Vol2 209 name server Vol2 201 packaging Vol2 200 Vol2 212 port number Vol2 221 run time startup Vol2 218 security error Vol2 199 seeing data moving Vol2 203 SOM DSOM implementation Vol2 211 startup delay Vol2 212 testing for TCP IP Vol2 202 threads Vol2 208 316 VisualAge for Smalltalk Handbook Fundamentals distributed continued tracing Vol2 195 transaction management Vol2 217 unloading feature Vol2 223 Windows 95 server Vol2 222 Windows for Workgroups Vol2 202 Distributed Data Management See DDM distributing application 252 distribution fees 9 distribution matrix Vol2 196 Vol2 201 Vol2 206 Vol2 210 DLL allocating memory Vol2 96 available platform function Vol2 96 closing 55 Vol2 98 debugging Vol2 86 Vol2 96 freeing Vol2 83 IPMD Vol2 86 LIBPATH Vol2 83 locking Vol2 98 memory leak Vol2 96 Oracle Vo
259. mory segments You can quickly identify the portions of your application that are using a lot of memory making it much easier for you to tune and improve that code The benchmarking workshop now lets you collect and store performance benchmark test cases You can make performance test runs using any and all of these test cases Results can be graphically displayed and compared with previous runs so that you can quickly see the impact of your performance tuning efforts Better callback support from C to Smalltalk has greatly improved the interoperability between C and Smalltalk This entry point can be passed to an external program when calling out to it from Smalltalk It gives that program an entry point to the Smalltalk object and selector it represents In C you can map the entry point to a function pointer making it very easy and natural to callback from C to Smalltalk When combined with ICs you now have powerful new options for packaging and delivering Smalltalk dynamically loadable application code that must call to and be called from programs written in other languages Database Performance Improvements and Enhancements Major performance and database security improvements are in store when you use DB2 static SQL support a new addition to VisualAge for Smalltalk in Version 4 0 Other database improvements include unified fields and samples headless server support and improved performance in applications using dynamic SQL In Ve
260. mparison with Random Strings As Keys Smalltalk coll Dictionary new slot key printString 136 137 coll LookupTable new slot key printString 119 121 Comparison with Floating Point Numbers As Keys 236 VisualAge for Smalltalk Handbook Fundamentals Smalltalk coll Dictionary new slot key 22480 coll LookupTable new slot key 18548 18877 Comparison with Integers in the 1 1000 Range As Keys Smalltalk coll Dictionary new slot key n truncated 1 59 59 60 65 coll LookupTable new slot key n truncated 1 51 49 53 Comparison with Integers in the 1 7654000 Range As Keys Smalltalk coll Dictionary new slot key n truncated 7654 1 64 61 60 coll LookupTable new slot key n truncated 7654 1 51 51 Concatenation and Streams Tip Strings can be formed from smaller strings by using the concatenation message comma or streams Here is a comparison of the two Chapter 4 IBM Smalltalk Programming Language 237 238 Smalltalk lumpSomeStrings arrayOfStrings bigLump bigLump String new arrayOfStrings do aString bigLump bigLump aString bigLump This is simple and straightforward but note that each assignment to bigLump involves copying the previous contents of bigLump to a new place and copying aString behind it When bigLump becomes long there is a lo
261. mport the applications that you want from the old into the new Chapter 5 ENVY 249 Question How do delete an application when there is no configuration map Unload the application Check the How Do I help from Transcript Deleting really just deletes an application from a configuration map it does not delete the application from the manager In your case your application is not yet associated with any configuration map and the best you can do is unload it from your image and try to forget it exists Creating a New Application Questioni Does creating a new application immediately write to the library manager Yes You can see this by creating an application and looking at the list of applications in an Applications Editions browser The name of your new application appears in the list Creating a new application does affect the library Unfortunately there is no way to remove your application except to purge it and clone the manager Or as we do start with a new manager and import the applications that you want from the old into the new Removing an Application Questioni How can remove an application from the loadable applications list You or your library supervisor can purge the application if it is versioned using an Application Editions browser See the IBM Smalltalk User s Guide Make sure that you unload the application version before purging it Deleting Old Versions of Classes Question Is ther
262. mutable 240 list part Vol2 59 loader 39 long living 219 marshaling Vol2 216 memory 187 mutable 241 partitioning Vol2 216 peer to peer communication primitive 217 printer Vol2 229 read only 227 reference 206 remote Vol2 197 sending as parameter Vol2 208 sending message to client image SOM Vol2 240 space Vol2 198 surviving flips table 187 traffic 21 transaction Vol2 110 undefined 69 Vol2 2 visualizer 21 writing to file Vol2 207 Vol2 203 211 217 object linking and embedding See OLE object space activator Vol2 203 connecting to different libraries connection close Vol2 196 different libraries Vol2 212 duplicating Vol2 214 Vol2 202 extending server class Vol2 215 fault tolerance Vol2 211 finding remote pointers Vol2 219 initial connection Vol2 203 moving parameters Vol2 215 partitioning object Vol2 216 performance Vol2 216 profiling Vol2 203 security files Vol2 222 sharing class instances Vol2 207 object oriented database Vol2 171 ODBC administrator Vol2 135 AS 400 access Vol2 5 AS 400 database Vol2 11 blocking Vol2 172 ClientAccess 400 Vol2 45 Vol2 48 create view Vol2 32 data source Vol2 135 data source name Vol2 191 DB2 400 Vol2 135 DBF format Vol2 171 default library Vol2 45 description Vol2 175 driver manager Vol2 48 file access part Vol2 60 host variable Vol2 42 keywords Vol2 157 license Vol2 191 log on Vol2 128 ODBC INI Vol2 45 Vol2 157 OS 2 Vol2 134 parameter mar
263. n A connection that causes an action to be performed when an event occurs See also connection event to script connection A connection that causes a script to run when an event occurs See also connection exception An abnormal condition such as an I O error encountered in processing a data set or a file execute To perform the actions specified by a program or a portion of a program execution The process of carrying out an instruction or instructions of a computer program by a computer expression In Smalltalk the syntactic representation of one or more messages An expression can consist of subexpressions representing the receiver and arguments of the message The expression can also cause the assignment of its result to one or more variables external source The format of Smalltalk source code that is filed out to an external file See also file in and file out Glossary 287 F feature 1 A major component of a software product that can be ordered separately 2 In VisualAge an action attribute or event that is available from a part s public interface and to which other parts can connect See also attribute and event field A group of related bytes such as name or amount that are treated as a unit ina record file 1 A generic term for the object type that refers to a database file a device file or a save file The system recognized identifier for the object type is FILE 2 In the hier
264. n 95 resource catalog 12 compiler 27 freeing up 24 retrieving display resolution 92 returning value modal dialog 94 reusable form 140 menu 108 reusing cursor Vol2 133 settings view 227 table part 149 153 Index 331 reusing continued visual class 65 visual part 140 reversing collections 186 revisable form text Vol2 50 rounding 182 router Vol2 4 Vol2 10 APPC Vol2 35 OS 2 client Vol2 21 starting automatically Vol2 59 row create Vol2 142 delete Vol2 142 loading all Vol2 179 locked Vol2 145 maximum number Vol2 153 removing brackets Vol2 182 rowsAsStrings Vol2 182 selecting multiple 150 RPC argument passing Vol2 36 asynchronous Vol2 42 asynchronous invocation Vol2 1 asynchronous job Vol2 12 ILE service program Vol2 24 large arguments Vol2 42 message Vol2 51 multiple programs parameter Vol2 34 passing data Vol2 36 setting commit boundary Vol2 1 synchronous Vol2 40 transaction Vol2 14 RPG Vol2 19 Vol2 32 Vol2 36 Vol2 40 Rumba Vol2 10 running subsystems runtime AS 400 prerequisites distribution fees 9 image reduced 47 Vol2 1 199 Vol2 9 S screen resolution 95 scraping Vol2 24 Vol2 111 size window position 93 332 VisualAge for Smalltalk Handbook Fundamentals script client Vol2 66 creating class from 229 double execution 70 server Vol2 66 TCP IP Vol2 66 scroll bar changing size 124 scrolling table 148 SCSI drive 40 security conversation Vol2 18
265. n Jose California He graduated with a degree in computer science from the Technical University in Darmstadt Germany Andi joined IBM in 1987 and worked as an application development specialist in large customer projects for IBM Integration Systems Services and at the German AS 400 Field Support Center Since joining the ITSO in 1994 he has taught workshops worldwide on object oriented application development and the Internet Andi is the author of three other VisualAge for Smalltalk books published by Prentice Hall You can reach him by e mail at bit acm org Vincent Dijkstra works as an Education Consultant at the IBM International Education Center La Hulpe Belgium He holds Bachelor of Arts and Master of Arts degrees in Technology and Policy from the Eindhoven Technical University Vincent started working for IBM in 1992 on a learning resource to assist managers and teams in transforming their organizations In 1994 he joined the IBM Object Technology University where he teaches Smalltalk VisualAge and more recently Java and analysis and design techniques You can reach Vincent by e mail at vdijkstra vnet ibm com Boris Shingarov received his Master of Science degree in Quantum Fields at Moscow State University M V Lomonosov in Russia He is the head of the Center for VisualAge and IBM Smalltalk Dialogue MSU providing VisualAge consulting and services all over Russia Currently Boris teaches VisualAge for Smalltalk courses at MSU He ca
266. n be reached by email at borisOvisualage dialogue msu su Preface XiX Acknowledgments XX This book has been a team effort par excellence even though most contributors were not even aware of being a team However we want to acknowledge everyone inside and outside of IBM who knowingly or unknowingly added information to the collection of invaluable hints and tips in this book Thanks go to Dave Allison Rainer Angstmann Jean Pierre Augias Wayne Beaton Jan Belik Paul Berglund Jonathan Bezuidenho Debu Bhattacharya Franco Biaggi Peter Boonen Chris Bosman Clark Toufic Boubez David Bourke Dave Bowman Mamie Branch Michel Brassard Chuck Bridgham Robert Brown Jordi Buj Jerry Callistein Jon Capezzuto Tony Carlier Janelle Carroll Ron Cherveny George Chiu Chris Clark Eric Clayberg Stephen Cooper Ellis Covington Tim Cowan Mark Cresswell Jim Crossgrove Greg Curfman James Curtis Chris Davia Kirk Davis Gordon Davis John DeBinder Ricardo Devis Bill Dickenson Stef van Dijk Sue Dubbeling John Earle Ralf Eberhardt Kevin Egolf Linda Fargo Ahmed Fattah Gerald Fischer Hans Forsberg Mike French Annick Fron Sabine Gaissert Ken Gelsinger Chris Gerken Michel Giroux Erick Godoy Tom Gordon Chris Grindstaff Juergen Guenauer Sven Guyet Tim Hanis Brad Hanks John Hansen Nicla Havrup Chris Hayes Frank Haynes Pam Helyar Andy Heys Hal Hildebrand Tim Hilgenberg Andrew Hobbs Steve Hobson Bryan Hogan
267. n framework provides support for incorporating OLE OCX and ActiveX controls in your application and makes it easy for you to write OLE clients in VisualAge for Smalltalk Off the shelf OLE and ActiveX controls can be placed on the VisualAge palette dropped on the application design surface and visually connected to other parts using the award winning construction from parts technology If you want to write OLE clients the framework provides high level abstractions for the OLE container concepts allowing you to focus on your Smalltalk application and not on the low level OLE programming interfaces Using the framework you can write OLE container applications that support embedding linking in place activation drag and drop and structured storage You can also write OLE automation controllers in Smalltalk that can control third party OLE automation servers such as Microsoft Word or Lotus 1 2 3 for Windows Windows 95 and NT 4 0 support many new or visually redesigned user interface controls and so does VisualAge for Smalltalk Version 4 0 You will find support for the new system slider progress bar tab strip toolbar tree view and status bar These are included in a new palette category in the VisualAge application builder for easy visual application construction as well as in the widget class library Image Components Developers of Smalltalk code are very familiar with the concept of an image An image is a file that contains all of t
268. n instance of Date as a result The same question applies to Strings representing Time You might want to write a method in the String class using the existing data converters Try something like this Smalltalk asDate AbtDateConverter new displayToObject self Chapter 4 IBM Smalltalk Programming Language 219 Smalltalk asTime abtTimeConverter new dispalyToObject self One point to watch for with this approach however is performance IBM Smalltalk type converters are intended primarily for handling user input If you peek into the implementation you see that there is a lot of code for error detection error handling and locale specific format support If you convert many strings repeatedly AbtTimeConverter object creation imposes significant overhead For example if you implement Smalltalk String gt gt asInteger AbtIntegerConverter new displayToObject self then this will result the following code to take up to 3000 milliseconds Smalltalk lab a 66543 b 10 7 Time millisecondsToRun 1000 timesRepeat b asInteger a asInteger For such cases reusing a cached AbtintegerConverter will yield a noticeable improvement You can change your implementation of String gt gt asInteger as follows Smalltalk String gt gt aslnteger self asNumber expect this to be over 30 times faster than the AbtIntegerConverter implementation but it obviou
269. n moving over a button do the Answer following 1 Create a new visual part 2 Put a push button in the window 3 Go to the Script Editor In the class definition for your part add an instance variable named cursor and save the class definition 4 Implement the following instance methods Smalltalk changeCursor Change cursor for Push Button1 display display self subpartNamed Window yourself primaryWidget display self freeCursor self cursor display createFontCursor CgConstants at XCGumby self subpartNamed Push Button1 yourself primaryWidget window defineCursor self cursor Smalltalk cursor Answer the currently selected CgCursor or nil cursor Smalltalk cursor aCgCursorOrNil Set or clear the currently selected CgCursor cursor aCgCursorOrNil Smalltalk freeCursor Free the cursor if one is allocated self cursor notNil ifTrue self cursor freeCursor Chapter 3 Graphical User Interface 99 Smalltalk undefineCursor Undefine the cursor for the window self subpartNamed Push Button1 yourself primaryWidget window undefineCursor 5 Go back to the Composition Editor and make the following connections a Connect openedWidget of the window to the changeCursor script b Connect aboutToCloseWidget of the window to the freeCursor script c Connect aboutToCloseWidget of the window
270. n the MLE Dropping an Item on a Push Button Questioni How can use the drag and drop operation between one item of a list box and a graphical push button representing a trash can It seems that when drop an item of the list box on the graphical button my icon is replaced by the label of the item What is described above is the default behavior However all of the drag and drop events are public so you can do whatever you want The way to get the graphical push button to remain graphical is to connect the dropped event of the push button to a script that accepts a parameter The parameter will be an instance of EwDropCallbackData It contains information on what you just dropped on the push button as well as other 144 VisualAge for Smalltalk Handbook Fundamentals things Be aware though if you connect from any of these drag and drop events you become responsible for what happens in these cases Changing a Part s Settings View Questioni created a new TextView part inherited from AbtTextView and extend it with a new attribute dataRequired of type Boolean to see if this field must include data or not Now want to add a toggle button for this attribute to the attributes page in the part s settings notebook found a class AbtTextViewAttributesPage in the subapplication AbtEditViewsSubApp which probably defines this attributes page In opening this view part do not see anything except some connections that point to
271. n these cases some real Internet machine must handle the mail on behalf of the listed domain name See also IP Number dynamic data exchange DDE A communication mechanism between processes that enables two applications to exchange data in a client server relationship dynamic link library DLL A file containing data and code objects that can be used by programs or applications during loading or at run time but are not part of the program s executable EXE file E EBCDIC Extended binary coded decimal interchange code A coded character set consisting of 8 bit coded characters edition In the VisualAge or IBM Smalltalk team programming environment a software component that is subject to further change A software component can have one or more editions identified by a time stamp stating the date and time of the edition s creation Many changes can be made to a single edition of a class In contrast every change to a method creates a new edition of that method In its broadest sense edition can include scratch edition and version EHLLAPI Emulator high level language application programming interface A programming interface that enables a workstation application to communicate with a mainframe application EHLLAPI operates in conjunction with a terminal such as 3270 emulator e mail Electronic mail Messages transmitted over the Internet from user to user E mail can contain text but also can carry with i
272. ncludeClasses 47 copy 222 packagerIncludeClassNames 49 53 copyright 200 packagerIncludeSelectors 49 Vol2 200 deepCopy 172 packagingRulesFor 50 defaultActionRequested 153 packagingRulesFor 52 deleteRow Vol2 142 plattormWidgetClass 87 destroyPart Vol2 249 platformWidgetGadget 87 disabling 56 postCreationInitialization 70 do 218 preferredConnectionFeatures 33 elements 194 prePackagingActionsFor Vol2 22 Vol2 33 equals to 182 primCommitUserlnput 152 eventTableAt put 225 printHex 186 exceptionOccurred Vol2 46 printNumber on 265 execLongOperation message 155 printString 210 executeQueryAsTransaction Vol2 145 printStringWidth 183 fileExists 178 prompt 94 finallnitialize 90 readAll Vol2 14 Vol2 41 Vol2 44 for do ifError Vol2 167 readAt Vol2 28 forMutualExclusion Vol2 16 readNext Vol2 27 getDiskFreeSpace 233 261 readNextKey Vol2 26 getQuerySpecNamed Vol2 153 receiverAtFrame 196 grabPointer 101 reconfigureAllSystems Vol2 27 grouping 66 registerLogonSpec Vol2 139 includedMethods 53 removeFromParentPart Vol2 249 initialize 168 reSort 194 initializeWhereClause Vol2 125 reverse 186 190 initializeWidgetClasses 87 rowsAsStrings Vol2 182 installToBeLoadedCode 254 selectionPolicy 223 interceptEvents 230 sender context 196 interface specification Vol2 71 sender signature 195 invokeAsynchronous Vol2 1 Vol2 12 Vol2 40 setGridLineStyleAndColor 36 isRuntime 201 setPosition 93 loaded 44 263 setSensitive 106 makeFixed 219 showBu
273. nd Windows Next export the strings to a file Edit this file under Windows and change all the characters VisualAge for Smalltalk Handbook Fundamentals that aren t mapped correctly After editing the file import the strings again under Windows When you run the application under Windows the new strings will be displayed The problem does not exist if you are using DB2 2 version 2 1 They take care of the code page translation for you Character Set Double Byte When installing on a Windows DBCS machine please use the default specified on the Select Folder dialog Because the English version of InstallShield does not support DBCS strings translated strings appear incorrectly in the list of existing folder names In the Simplified Chinese environment on AIX several of the dialogs may have strings truncated vertically and horizontally because of the system font used by VisualAge for Smalltalk By installing a different set of font aliases for Simplified Chinese or changing the named fonts for several VisualAge for Smalltalk dialog controls button labels headings and subheadings icon text and text the truncated strings will appear correctly To change the VisualAge named fonts used for settings pages and icon text please refer to the VISUALAGE NAMED FONTS section of the Preferences Workspace The Preferences Workspace can be displayed by selecting Options gt Preferences Workspace from the VisualAge for Smallt
274. nd write them out to files again in Smalltalk Besides other revision control systems are doing just that in their own way A much more sophisticated approach is to look into the support provided by the LibraryObjects application This allows you to associate any object that can be persisted by the ObjectDumper with a given class in an application All that you need to add to this is some trivial CommonFileSystem code to read your files into a byte array for storing and some code to write the byte array back out to a named file for restoring This gives you the version control that you are looking for lt has the added benefit that your files can be binary or text You can t store binary files in the comment fields unless you use something like uuencode to turn them into a stream of hexadecimal charaters Date Stamp for Versioned Classes Answer An editioned class or application has a date created stamp What about after you ve versioned the class or application How can see from the browser or manager what the date of the versioning is Versions are really just editions but in a versioned state Therefore even though you are looking at a versioned edition you can still find out its timestamp but it is the timestamp when the edition was created If you want the version name to include the timestamp as part of its signature do the following From the Transcript menu select Smalltalk tools Chapter 5 ENVY 247 Open Pr
275. nder another name Be sure to keep your base image updated with any fixes Creating a New Image Questioni How do create a new image Answer With the Standard Edition of VisualAge for Smalltalk if you have backup copies of the files sources es changes log abtdev pom and image then you can copy these files into your VisualAge for Smalltalk subdirectory and launch If you do not have backup copies of these files then it will probably be best to reinstall to get a new image To avoid reinstalling in the future make backup copies of these four files and keep them where you can access them Be careful to file out applications you would like to keep If using VisualAge for Smalltalk Team Version 2 change into your VISUALAG directory on the server From there change into either the OS2 or WIN subdirectory depending on whether you are using OS 2 or Windows Then change into the client subdirectory Within this subdirectory there is an image file that you can copy into your client VisualAge subdirectory You can either rename your old copy or delete it depending on whether you want it backed up or not VisualAge for Smalltalk Professional Version 3 0 no longer supports two step centralized installation so you must ensure that you always Copyright IBM Corp 1997 23 have a backup copy of the virgin image or of the image with only the features installed Reducing Image Size 24 Answer My image has grown significan
276. nents of the product and applications within those configuration maps Whenever you open an application to make a change you immediately release the application s edition to the configuration map opening the configuration map as well if necessary Now to get the latest and greatest check out your configuration maps to see if any new application editions have been released and if so you can load them if you are interested Once you have open application editions you can see any newly released classes by examining the application in the Application Manager If the released class does not match the one currently loaded in your image it will have a gt symbol next to it To further assist you there is a Query menu option under Smalltalk Tools on the Transcript window The choice for unreleased classes will print a list to the Transcript of every class in your image by application that is not the released version for that application You can also use this in addition to Open Class Editions to help you locate all the changes you have made leading up to a build so you know what you need to version and release ENVY Windows95 Novell Answer What about accessing ENVY Manager library using Windows 95 clients and Netware servers IBM has recently certified ENVY Manager library access using Windows 95 clients and Netware 3 12 and 4 1 servers Windows 95 clients must use only the Novell Client32 for Windows 95 requestor IBM has teste
277. net Internet users may find additional material about new redbooks on the ITSO World Wide Web home page Point your Web browser to the following URL http www redbooks ibm com redbooks IBM internal users may also download redbooks or scan through redbook abstracts Point your Web browser to the internal IBM Redbooks home page http w3 itso ibm com redbooks Preface XVil xviii If you do not have World Wide Web access you can obtain the list of all current redbooks through the Internet by anonymous FTP to ftp almaden ibm com cd redbooks get itsopub txt The FTP server fip almaden ibm com also stores the sample software from the diskettes accompanying some of the redbooks To retrieve the sample files issue the following commands from the redbooks directory cd SG24xxxx lt Redbook number binary get SampleFile EXE ascii get SampleFile TXT All users of ITSO publications are encouraged to provide feedback to improve quality over time Send questions about and feedback on redbooks to redbookOvnet ibm com or REDBOOK at WTSCPOK or USIB5FWN at IBMMAIL If you find an error in the software that is supplied with a redbook please send a bug report with a description of the problem to bugs vnet ibm com To receive regular updates on new redbooks and general IBM announcements you can subscribe to the IBM Announcement Listserver It automatically supplies an Internet e mail user with timely new announcement inf
278. ng in Windows now but are considering also doing some AIX development My understanding is that this would require us to move our manager to AIX Is the procedure for doing this documented somewhere took a quick look through the VisualAge for Smalltalk Users Guide where other library administration tasks are documented but didn t see anything assume that there s more to it than just copying the manager file but what Chapter 5 ENVY 255 Answer You should reinstall the server code on AIX following the instructions in the READMEs and so on and then copy your library file from Windows over the library that was added during the server install on AIX Also all of your clients will need to update their abt cnf to point to the new library location and to use EMSRV as the transport mechanism Identical Users 256 Answer In our team development environment we have two distinct users who have the same name suppose this happened from importing classes from another library or maybe there is a space after the name In any case can anyone make a recommendation as to how best to get rid of one of these users Right now they are both owners of different classes and managers of applications Assign new owners or managers to the classes and applications created under the user that you don t want To do this use the Become New Owner and Become New Manager options of a Group Members menu Next you might want to check for an
279. ng picture makes this clear Behavior ClassDescription YourClass For example the method new is not a class method of Object but all classes understand it That s because the class Object is itself an instance of the metaclass Object which in turn is an instance of the metaclass When you execute YourClass new method lookup starts in YourClass class and continues to Object class but Object class itself is inherited from Class Chapter 4 IBM Smalltalk Programming Language 175 and Class is indirectly inherited from Behavior and Behavior has an instance method new If you look at all public instance methods of Behavior then you will see new which basically calls a primitive VMprBehaviorBasicNew don t know why it doesn t appear in the catalog of classes as it is contained in the CLIM API methods category You ll see what I m talking about by selecting Browse Class in your System Transcript and entering Behavior File System 176 Answer How do get the contents of a directory The contents of a directory can be determined by using an instance of CfsDirectoryDescriptor For simplicity a reusable class named FileManager can be created to provide higher level abstractions of the Common File System API The following method evaluates a block with the names of the files in a directory that match a given pattern Smalltalk filesMatching pattern on pathName do block Evalut
280. ng that when an application is listed as a prerequisite for another no mention of the appropriate version is made Before packaging ensure that the appropriate versions of all applications have been loaded The packager uses the prerequisites when building a runtime image Missing Classes in the Run time Image 52 The packager starts with the collection of all classes in the application and all prerequisite applications From that starting point it extracts all classes and methods which are not explicitly referenced in code If you use any metaclass tricks like asking a class for its subclasses those subclasses would not be explicitly referenced and would therefore be excluded The packager can be coerced into including certain classes by adding a new class method to the class with the same name as your application VisualAge for Smalltalk Handbook Fundamentals Smalltalk packagerIncludeClassNames aString Answers a collection containing the names of the classes which must be included when packaging MyFirstClass MySecondClass The class with the same name as your application can hold behavior that is specific to your application in its class methods This class is a subclass of the class called Application which is itself a subclass of SubApplication In the class SubApplication you find similar methods that force specific methods or classes to be included or excluded when packaging Missing Meth
281. ng to HTTP The server usually responds with HTML data but can send other kinds of objects as well hypertext Text in a document that contains a hidden link to other text You can click a mouse on a hypertext word and it will take you to the text designated in the link Hypertext is used in Windows help programs and CD encyclopedias to jump to related references elsewhere within Glossary 289 the same document The wonderful thing about hypertext however is its ability to link using HTTP over the Web to any Web document in the world yet still require only a single mouse click to jump clear around the world icon A small pictorial representation of an object image A Smalltalk file that provides a development environment on an individual workstation An image contains object instances classes and methods It must be loaded into the Smalltalk virtual machine in order to run implementor For any given message selector a method that implements that selector IMS Information Management System Virtual Storage inactive 1 Not operational 2 Pertaining to a node or device not connected or not available for connection to another node or device independent LU A logical unit LU that does not receive an ACTLU over a link Such LUs can act as primary logical units PLUs or secondary logical units SLUs and can have one or more LU LU sessions at a time Contrast with dependent LU index A set of pointers
282. not happy with the rate of garbage collection you should be able to override the default interval of garbage collection and force it whenever you want We noticed that IBM Smalltalk will appear hung sometimes since the garbage collector is invoked only when the system is idle but if you are running a long running task that creates a lot of objects you can run into a situation where you blow the available memory The way we worked around it is by creating a high priority background task that wakes up every few seconds and checks if the available memory is running low If it is we force the garbage collect ourselves It seems a patch that should not be necessary but it made our hang ups go away VisualAge for Smalltalk Handbook Fundamentals Inherited Messages Question How can see all inherited messages The best way to see all messages that instances of your class can understand is to change the value for method visibility on the Class menu of most browsers this will show inherited methods as well as methods defined on your class itself With the class methods things are a bit more tricky There are class methods that you don t see in any of your object s superclasses up to Object but which your class still does understand For example suppose YourClass is a subclass of Object YourClass class does understand the message new but it s not a class method of either YourClass nor Object How this can be A look at the followi
283. nowhere In testing the view part get the attributes page Why do get this behavior It is a little strange but you are not seeing anything because the form has no size when you edit the settings page It has no attachments so it tight wraps around its children Here s what you can do 1 Select View Parts List to bring up its settings and change its size to nonzero 2 Modify the view as you want 3 Generate archival code and remove the code that sets the form size 4 Regenerate the run time code see the test method in the archival code for details Steps 3 and 4 are necessary because the Composition Editor does not provide a way to specify that the form is an unattached form what is called a shrink wrap form Hiding Table Columns Dynamically Tip If you want to hide one or more columns of a table here is what you have to do Unfortunately no action is available that lets you hide a column You can however hide the entire table As a work around you can simulate the wanted behavior by manipulating the ratioWidth of the column Setting the value to zero will make it look as though the column has been hidden Chapter 3 Graphical User Interface 145 Initializing a View Wrapper Question When I use a view wrapper the widget does not get created until send it Answer the openWidget request Therefore can t do anything for example set some of its features until after the first time I ve iss
284. ns the method Of course that means there is just one copy around and that may not be what you want at all Chapter 4 IBM Smalltalk Programming Language 167 Note The construct is different from the construct The will evaluate whatever is in the parentheses making it possible for a method to return a constant such as Date today which is the date the method was compiled Note that the answer is an actual Date instance The construct is an atom EsAtom You can also use for example the expression hello hello is true There is only one instance of an atom with some name Once you create an atom you cannot access or change the data in it So atoms are really used for state purposes to avoid using symbols to make packaging easier in IBM Smalltalk m Watch this The construct is not documented in the IBM Smalltalk manuals Use it at your own risk Question But IBM Smalltalk Version 3 does many optimizations automatically so don t need for this Is there a nontrivial example of usage of Yes for example you can use it to take some specific action each time you recompile the class See the next section Taking Actions Automatically at Class Recompilation for details Taking Actions Automatically at Class Recompilation Questioni Typically the initialize method is run once when a class is loaded which most systems do automatically when i
285. nsider one of the following 1 The easiest way to disable the mouse pointer is to use the message grabPointer This method is an instance method in CwComposite The argument is a cursor So you can send it the clock cursor and you won t have to set that up yourself This method sends all mouse input to the shell regardless of where the pointer is on the screen This is also the bad part as the user can t use the mouse for other things When you are done send the message ungrabPointer 2 Another way is to add an event handler when you start the processing You can do something like this Smalltalk shell addEventHandler ButtonPressMask receiver self selector eventHandler clientData event clientData nil The advantage of this method is that it applies only when the mouse pointer is in the window Call the above when you want the input blocked When you are done call the above again except change addEventHandler to removeEventHandler Make sure to add CwConstants to the class s pool dictionaries Now you need to add the method eventHandler clientData event which gets called when there is input You can either leave this method blank to do nothing or maybe use the following option 3 To implement a beep add the PlatformFunction pool dictionary to the class The following is valid for OS 2 Chapter 3 Graphical User Interface 101 Smalltalk eventHandler widget clientData clientDate event event There h
286. nsive libraries of classes a rich set of preexisting parts from IBM and other vendors wrappering of existing COBOL C IMS transactions or VBX controls and multimedia authoring support VisualAge enables rapid assembly of applications with minimal new code VisualAge for Smalltalk supports development on Windows OS 2 or AIX with full portability of applications across these target platforms It combines the power of a pure object oriented environment with the ease of visual programming Users can connect prefabricated reusable components or extend these components with user created code VisualAge for Smalltalk eases the learning and implementation of object oriented technologies VisualAge for Smalltalk supports multiple client server models GUI construction popular communications and transaction protocols access to industry leading databases the CORBA standard for object interoperability and multiple legacy interfaces VisualAge for Smalltalk Standard is the entry level product for individual programmers The Professional product for individuals or teams includes version control and configuration management The Professional Server product includes a LAN repository for team development Add on components include support for native ORACLE data access communications and transactions reports AS 400 IMS and distributed objects VisualAge for Smalltalk Technology Question What type of technology does VisualAge use Application d
287. nswer from the system menu the Dependent dictionary does not contain the ordered collection You are leaving dependents lying around because you are using the private closeWidget method You should use the closeWidgetCommand method instead You could use the Script Editor to paste the proper action closeWidgetCommand into your method Removing the Close Menu Option Answer How do disable or remove the Close menu option on the system menu for a window You can t but you can add a closeWidgetRequest callback That is a callback that is invoked before a shell is closed If you set the doit to false the window is not closed Normally this is used to display an Are you sure message before closing the window See AbtApplicationsOrganizer gt gt confirmCloseRequest for an example It hooks the closeWidgetRequest event to a script Widget Warning Circular Reference Answer am getting a warning in the Transcript CwForm circular reference My application works fine but would like to get rid of the warning What should look for This means that you have one widget whose attachments are dependent on another widget and the other widget s attachments are dependent eventually if not immediately on the first widget Here s an example of circularity Widget A s bottom edge is attached to Widget B s bottom edge while Widget B s left edge is attached to Widget A s right edge Chapter
288. nt listed in the VisualAge section of the load and unload dialog make the fourth letter of your DAT file name a t To have your component listed in the IBM Smalltalk section of the load unload dialog make the fourth letter of your DAT file name an e Unloading the Visualization Feature Tip To unload the Visualization feature first execute the following code from a workspace Smalltalk DtEventProfilerApplication eventQueueProcessor Then unload the Visualization feature Manager Access 82 Tip Watch out for the following manager access issues Solaris Server Error 1212 Transaction terminated prematurely message When running EMSRV on Sun Solaris 2 5 1 you may get an Error 1212 Transaction terminated prematurely message when loading a large config map This is an access denied error due to an incorrect return value from one of the Solaris lock checking functions Temporary patches from Sun are available to fix this problem You can download these patches from Sun s FTP site ftp sunsolve1 sun com pub patches T 103640 06 tar Z e Starting EMSRV EMSRV for Solaris does not determine the device number correctly In most cases images that talk to it fail to connect with the message File resides on unsupported device This error also prevents the use of the EMCOPY command VisualAge for Smalltalk Handbook Fundamentals To resolve the problem start EMSRV with all the options
289. nterface 137 Hot Spots Question If try to set the borderWidth attribute for a hot spot either from the General page for the part or from code see these settings when query the value However what is the reason that won t be able to actually see the border SM You can t see the hot spot because it is never mapped It is generally used as a clickable spot for images hence it does not draw any border How can create hot spots that can be reshaped Mo Create a subclass of AbtHotSpot overriding the containsPoint method Create a subclass of AbtHotSpotView and override postCreationInitialization to use your AbtHotSpot subclass Hot spots can only be rectangular However if you need a nonrectangular shape you can try using multiple smaller hot spots that are next to each other to approximately cover the area you need How do find the coordinates of a hot spot BAMA To get the x and y coordinates of the hot spot send it the message x or y To get its width and height send width or height This is true for all parts Links What is a link in the world of drag and drop BAMA Link means that the instances dropped get added to the target and remain in the source Copy duplicated the instances and move deletes them in the source Wallpaper How do display an image as a wallpaper with more than 16 colors Here s a complete script you can use and connect to the openedWidget event of the window 138 Vis
290. ntinued manager 249 moving code 251 components 246 to AIX 255 object space Vol2 212 password protection 244 protecting 244 remote access 243 reuse 244 shared folder Vol2 4 single user mode Vol2 23 LIFO Vol2 36 limiting lines in MLE 156 link 138 list adding icon 129 widget 223 list box behavior 112 container column 119 drag and drop 110 144 scrolling 112 literal field Vol2 109 string 221 strings 227 text Vol2 252 loading application 245 application in run time image 47 different image 30 feature 253 variable references 198 local log on Vol2 131 locale 264 locating widget focus 136 location mouse pointer 102 reference Vol2 196 window 90 lock releasing 83 locking compatibility Vol2 128 file Vol2 45 row Vol2 145 locking continued scheme Vol2 128 log off automatic 202 logical file Vol2 48 record format Vol2 47 unit of work Vol2 72 Vol2 78 long field Vol2 130 lookup table using 234 looping walkback 56 LU 6 2 Vol2 109 macro file Vol2 113 manager class 66 cloning 250 consistency 253 growth rate 254 size 250 managing network traffic Vol2 211 mapping widgets across systems 87 marshaling Vol2 216 maturity VisualAge 2 maximized window opening 92 maximizing window 91 MCHO0802 Vol2 34 member physical file Vol2 11 memory allocation 39 garbage collection 174 invalid location 73 leak Vol2 96 menu accelerator key 157 adding choices 105 disabling button 106 dynamic 105 for
291. ntributions questions or answers hints and tips VisualAge for Smalltalk Handbook Fundamentals Many thanks go to Alexis Scott Nancy Lewis Paul Braun and Shawn Walsh at the ITSO Raleigh Center for their great administrative support and to Pat Donleycott ITSO Raleigh Center Manager for hosting the residency Thanks also to Shirley Hentzell and Maggie Cutler for their outstanding editing of this book to Liz Rice for her editorial assistance and to Geoff Nicholls without whose advice this book would not have a decent index Comments Welcome Your comments are important to us We want our redbooks to be as helpful as possible Please send us your comments about this or other redbooks in one of the following ways Fax the evaluation form found in ITSO Redbook Evaluation to the fax number shown on the form e Use the electronic evaluation form found on the Redbooks Home Pages at the following URLs For Internet users http www redbooks ibm com For IBM Intranet users http w3 itso ibm com e Send us a note at the following address redbook vnet ibm com Preface XXi XX VisualAge for Smalltalk Handbook Fundamentals Chapter 1 What Is VisualAge for Smalltalk Description of VisualAge for Smalltalk Question What is VisualAge for Smalltalk VisualAge for Smalltalk is a client server rapid application builder for constructing state of the art flexible scalable business applications With exte
292. nvironment Anyway you can try this after calling Compiler class gt gt compile inClass Smalltalk compiledMethod methodClass install compiledMethod asPrivate asPrivateBoolean withSource sourceString ifNewAddTo compiledMethod methodClass controller categorizeln all the categories you want However suggest you instead call compile notifying ifNewAddTo categorizeln or compileAsPrivate notifying ifNewAddTo categorizeln which is the preferred method Chapter 4 IBM Smalltalk Programming Language 229 Keyboard Event Handler 230 Question need to be able to capture the following key pressed events Answer e Shift F10 Activate Pop up Menu Alt F6 Switch between associated windows I m able to capture single key pressed events but not multiple ones Is there a way to use IBM Smalltalk to capture multiple key pressed events other than menu accelerator keys Does VisualAge provide a mechansim for capturing multiple key pressed events Yes it is possible to capture multiple key pressed events See below for a tehnique to do this As to Shift F10 and Alt F6 on the Windows 95 version of VisualAge these two particular events are not trappable that is they do not generate Cw event handler callbacks suspect this is because the native widget is trapping these or they have operating system significance There is some interesting protocol with interceptEvents and CwOverrid
293. nvironments do so at their own risk The following terms are trademarks of the International Business Machines Corporation in the United States and or other countries AIX AIX 6000 Application System 400 APPN AS 400 CICS Common User Access CUA DATABASE 2 DB2 DB2 2 DB2 400 DB2 6000 IBM IMS MQ MQSeries MVS MVS ESA Object Connection OS 2 OS 400 Presentation Manager PS 2 RPG 400 SOM SQL 400 TalkLink VisualAge VisualGen Visuallnfo The following terms are trademarks of other companies C bus is a trademark of Corollary Inc PC Direct is a trademark of Ziff Communications Company and is used by IBM Corporation under license UNIX is a registered trademark in the United States and other countries licensed exclusively through X Open Company Limited Microsoft Windows and the Windows 95 logo are trademarks or registered trademarks of Microsoft Corporation HP HP UX Hewlett Packard Company Sun Solaris Sun Microsystems Inc Lotus Notes Lotus Development Corporation Other trademarks are trademarks of their respective companies VisualAge for Smalltalk Handbook Fundamentals Appendix B Related Publications The publications listed in this section are considered particularly suitable for a more detailed discussion of the topics covered in this redbook International Technical Support Organization Publications For information on ordering these ITSO publications see How to Get ITSO Redbooks on page 275
294. o non LAN PC 252 global variables 205 importing 245 launching 203 LibraryObjects 247 loading 47 245 merging 49 MQ sample Vol2 76 multiple windows 89 native Vol2 8 not owned 61 owner 256 packaging Vol2 57 Vol2 251 packaging distributed Vol2 212 prerequisites Vol2 22 purging 250 releasing 61 reloading current edition 249 removing 250 report packaging Vol2 230 running unattended Vol2 129 sharing data Vol2 43 sharing query Vol2 145 start execution 203 synchronizing AS 400 and VisualAge Vol2 8 unable to version 61 unloading 56 using 248 versioning 61 application prerequisites 52 ApplicationLoader 47 apply push button 38 architecture GUI 87 layered 63 archival code 32 34 54 68 246 arguments command line 200 array Vol2 37 AS 400 5250 screen Vol2 24 accessing VisualAge application Vol2 8 APPC Vol2 7 APPC configuration Vol2 33 asynchronous job Vol2 12 blocking factor Vol2 15 308 VisualAge for Smalltalk Handbook Fundamentals AS 400 continued busy cursor Vol2 17 code page Vol2 12 commit boundary Vol2 1 communication error Vol2 2 complex data structures Vol2 37 compound key Vol2 29 configured systems Vol2 2 connecting Vol2 18 connecting to Vol2 2 connection feature reinstalling Vol2 8 connection problem Vol2 35 data queue Vol2 34 database Vol2 11 DDM Vol2 26 DDS Vol2 31 document Vol2 50 examples Vol2 14 feature installation Vol2 23 file access part Vol2 4 fixpack problem Vol2 54 ILE Vol2 24
295. ocation such as a node station or particular terminal to which information is to be sent device An input output unit such as a terminal display or printer dictionary In Smalltalk an unordered collection whose elements are accessed by an explicitly assigned external key See also pool dictionary digital 1 Pertaining to data in the form of digits Contrast with analog 2 Pertaining to data consisting of numerical values or discrete units disabled 1 Pertaining to a state of a processing unit that prevents the occurrence of certain types of interruptions 2 Pertaining to the state in which a transmission control unit or audio response unit cannot accept incoming calls on a line display 1 To present information for viewing usually on a terminal screen or a hard copy device 2 A device or medium on which information is presented such as a terminal screen Display 1 A Smalltalk command that executes the selected code and displays the result 2 In IBM Smalltalk an X Motif concept that models the user s hardware display The functions of the X Motif Display object are implemented in the IBM Smalltalk CgDisplay class distributed application A workstation application that runs in cooperation with programs running on other processes or machines Client server applications are a subset of distributed applications distributed computing environment DCE A set of services and tools that support the
296. ock Smalltalk self traceShowBlock l am entering method blah for self printString with myArg printString Then in the trace block code do this Smalltalk traceShowBlock aBlock self isTracing ifTrue traceLog cr show aBlock value In this way you can leave your trace code in the system without paying a steep performance penalty The string is only built when tracing is active Closing a DLL from Smalltalk Tip If you are developing a Smalltalk application that calls C or COBOL functions in a DLL when you initially call the DLL function Smalltalk opens the DLL and leaves it open If you need to change the DLL code the DLL must be closed To avoid having to shut down Smalltalk execute the following Smalltalk PlatformLibrary logicalName myDIIName close Chapter 2 General Information 55 Unloading When Instances Exist Tip To unload an application when instances exist execute the following Smalltalk MyClass basicAlllnstances do each each become Object new Using basicAllinstances is faster than using allInstances because a garbage collection is not performed Testing When Looping Walkbacks Occur Tip When testing while a looping walkback occurs such as in the midst of a losingFocus callback use the following Smalltalk GloballsTesting ifTrue GloballsTesting false self halt Then execute
297. od in Package Answer try to package a reduced run time image After the packaging process has finished it seems that the package is missing the method convertToCodePage of EsString even though it is referenced several times Is there a way to force a method to be packaged You can force the method to be included by the packager by adding a class method called includedMethods to the class with the same name as your application This method returns an array of methods to be included in the packaged image An example of this method is listed below Smalltalk includedMethods Return a list of methods to be included in the packaged image Array with ToDoListView gt gt test Chapter 2 General Information 53 Run time Image Packaging Problem Tip Messages about OS2 INI not being able to be saved have usually been the result of insufficient disk space which would also lead to slow execution since the swapper cannot grow so check that first Another cause of slow execution is not having ABTBYTES DLL in the LIBPATH or PATH under Windows As for the run time image itself more than 5 MB is way too large unless you have a truly huge application This is typically caused by having the wrong prerequisites for your application A common example is when your application requires AbtBuildViewsApp part of the application builder development environment This usually happens if you generate archival code into your app
298. ods 67 CLIM API 175 ES Internal 172 instance methods 66 naming 66 CCSID Vol2 12 cell hover help 157 monitor changes 149 centered opening window 93 change management 247 changing label color 120 mouse pointer 98 object class 231 scroll bar size 124 table cell 149 format 36 size 149 310 VisualAge for Smalltalk Handbook Fundamentals channel file character Vol2 73 identity 240 replacing in string 222 strange Vol2 3 character set translation table 44 check box container CICS 119 accessing COBOL Vol2 71 callback Vol2 104 code page translation Vol2 73 ECI Vol2 72 Vol2 73 EPI Vol2 115 EPI identification Vol2 110 harclock Vol2 110 literal Vol2 110 logical unit of work Vol2 72 LU2 identification Vol2 109 opening proc dialog Vol2 72 program Vol2 72 screen scraping Vol2 111 transaction abend Vol2 72 circular reference 97 class AbtAppBldrPart 208 AbtAppBldrView 32 AbtCompoundType AbtConverter 210 AbtDatabaseSamples Vol2 140 AbtDateConverter 212 219 AbtDateParse 213 AbtDeferredUpdatedManager 31 AbtEditDatabaseSupport Vol2 153 AbtError Vol2 97 Vol2 165 AbtForeign Vol2 73 AbtForeignRecord Vol2 73 AbtFrameView 109 AbtlbmCliDatabaseManager AbtlomDatabaseConnection AbtlbmResultTable Vol2 163 AbtintegerConverter 219 220 AbtObservableObject 24 AbtOracleLongField Vol2 130 62 Vol2 98 Vol2 166 Vol2 167 AbtPart 208 AbtPointer Vol2 81 AbtProgramStarter Vol2 84 AbtQuerySpec Vol2
299. of development products VisualAge for Smalltalk allows software developers to create highly portable scalable multitier business applications that take advantage of emerging technologies such as the World Wide Web Activex OLE and OLE controls OCX as well as seamlessly integrate existing legacy C COBOL CICS DB2 IMS and Tivoli systems Version 4 0 takes the next step in enabling global enterprises to quickly construct line of business applications that are portable highly scalable and simple to maintain and fit easily into existing IT infrastructures VisualAge for Smalltalk Handbook Fundamentals VisualAge for Smalltalk is now available on more UNIX Windows and OS 2 platforms than ever before In addition to the existing OS 2 Warp V3 0 AIX V4 1 4 4 2 Windows 3 11 Windows 95 and Windows NT 3 51 new platforms supported are HP UX V10 10 Sun Solaris V2 5 S 390 MVS OS 2 Warp V4 0 and Windows NT 4 0 On Windows 95 and NT OLE and ActiveX are now supported as well as new native user interface controls Version 4 0 is now registered and certified for the Designed for Microsoft Windows NT and Windows 95 logo Version 4 0 brings further performance enhancements usability improvements tool enhancements and enhanced packaging support Performance has been improved through the introduction of image components ICs which allow developers to create dynamically loadable modules that partition a Smalltalk application into small
300. of Cglcon Drag and Drop Question have developed a drag and drop intensive application under OS 2 that works just fine When tried to port it to Windows expected it would work like the native style right button drag on OS 2 left button drag on Windows but see this is not the case I still have to drag with the right mouse button on Windows Why Chapter 3 Graphical User Interface 129 The drag and drop function built into VisualAge is completely emulated and has nothing to do with the operating system settings Which button is used internally is completely under Smalltalk control The default is right button drag under all operating systems If you want to use the left button on Windows to make the user interface on Windows conform to its standard give this a try Smalltalk EwDragAndDropManager default button Button1 Multiline Text Question am developing my GUI via the Composition Editor added a text label but now want it to be multiline have a window like this but want it to look like this Is there a way to achieve this 130 VisualAge for Smalltalk Handbook Fundamentals Yes Connect the abelString attribute of the label to this script Smalltalk label cr cr CldtConstants at LineDelimiter this is cr a pen Window Titles If a window is going to appear in the OS 2 task list the title is clipped by OS 2 to 64 characters When w
301. ollowing code snippet Smalltalk myWindow openWidget or use any other message such as openOwnedWidget myWindow suspendExecutionUntilRemoved code to be executed when the window is closed goes here Closing a Window Questioni What is the difference between closeWidget and destroyPart for a window The closeWidget action will destroy the widget The destroyPart action will destroy the widget and release all connections You want to destroy the part when closing the owning window to be sure that all connections are freed otherwise dependencies will be left around and your image size will grow Resolution Independent Screen Question When I change the screen resolution say from 800 600 to 1280 1024 the text does not seem to scale properly If there is a text label before an input field the text ends up overlapping the input field Is there a platform independent solution to fix this The best way to do this is by using widget attachments Using the widget attachments attach the right edge of the label field with either no attachment or attach it to its own left edge with 9 to 11 offset points per character of text in the label Then attach the left edge of the text field to the right edge of the label field with an offset of 2 or 3 pixels To be safe attach the top and bottom of the text field to the top and bottom of the label field with an offset of zero If you want to get really fancy group controls on
302. ollowing method Smalltalk fillContainer itemsCollection defaultAction aScriptName iconGadget AbtlconGadgetView new label each largelcon icon parentView container openWidget menu self subpartNamed Menu yourself lt add this line yourself By adding that one line you can now click anywhere inside the container including on top of the icons and see a context menu VisualAge for Smalltalk Handbook Fundamentals Another variation to the use of context menus within a container is to click the second mouse button on top of the icon and see a context menu but not see a context menu when you click the second mouse button from anywhere else in the container To do this edit the same method except that the same segment of code now looks like this Smalltalk iconGadget AbtlconGadgetView new label each largelcon icon parentView container openWidget menu self subpartNamed Menu yourself createWidget setPostCreationSettings yourself yourself In addition to changing this piece of code you also must delete the connection between the container s menu attribute and the menu s self attribute After these few changes you should be able to see a context menu by clicking the second mouse button on the icons only not on the container s surface Refreshing a Container Details View Questioni What is the refresh design for a container details v
303. ome cases a single instruction or an address that passes control and parameters between separate portions of the computer program 4 To interconnect items of data or portions of one or more computer programs 5 In SNA the combination of the link connection and link stations joining network nodes listserv An Internet application that automatically serves mailing lists by sending electronic newsletters to a stored database of 292 VisualAge for Smalltalk Handbook Fundamentals Internet user addresses Users can handle their own subscribe unsubscribe actions without requiring anyone at the server location to personally handle the transaction literal An object that can be created by the compiler A literal can be a number a character string a single character a symbol or an array All literals are unique Two literals with the same value refer to the same object The object created by a literal is read only it cannot be changed literal text Text in an HTML Text part that is passed to the client browser exactly as entered You can use literal text to code HTML tagging that is not directly supported by the Web Connection parts load A system operation that links the compiled code for a software component from a library into an active image Loading also performs other operations that enable the component to run such as linking prerequisites local address In SNA an address used in a peripheral node in place of an
304. ome way of forcing these events to be handled right away so that the updates to the status text window will be synchronous To do so try the updateWidget message For example here is a sample script for a window with a button a text part and a label This script should be invoked from the button click Smalltalk buttonClicked Demonstrate how to update text on a widget 1 to 100 do i self subpartNamed Label1 object i printString self subpartNamed Label1 primaryWidget updateWidget self subpartNamed Text1 object i printString self subpartNamed Text1 primaryWidget updateWidget self subpartNamed Push Button1 object i printString All of these controls will reflect the changes instantly The push button does not need to have an update Widget Incremental Compiler Answer Does IBM Smalltalk come with an incremental compiler Yes IBM Smalltalk does use incremental compilation Incrememental compilation means that when you save a changed Smalltalk program typically quite short it is compiled as part of the Save process you don t have to recompile everything in the Smalltalk application just what you ve changed You rarely notice the compiler working it s so fast Chapter 4 IBM Smalltalk Programming Language 191 IBM Smalltalk comes with a lot of other features for programmer productivity the TrailBlazer code browser unique to IBM application chan
305. on super finallnitialize Positioning Window at Cursor Question How do initially position the window where the cursor is Look at the following code 90 VisualAge for Smalltalk Handbook Fundamentals Smalltalk finallnitialize rootXReturn rootYReturn CgDisplay default queryPointer CgWindow default rootReturn ReturnParameter null childReturn ReturnParameter null rootXReturn rootXReturn ReturnParameter new rootYReturn rootYReturn ReturnParameter new winXReturn ReturnParameter null winYReturn ReturnParameter null maskReturn ReturnParameter null self initWidgetSize Rectangle origin rootXReturn value rootYReturn value extent 300 200 super finallnitialize Maximizing a Window Questioni Is there a way to maximize a window programmatically Moe There are platform specific ways to maximize and minimize a window In Windows Smalltalk Code for maximizing a window self primaryWidget osWidget handle showWindow SwShowmaximized Code for minimizing a window self primaryWidget osWidget handle showWindow SwShowminimized e In OS 2 Chapter 3 Graphical User Interface 91 Smalltalk Code for maximizing a window self primaryWidget osWidget handle winQueryWindow QwParent winSetWindowPos nil x O y O cx O cy O fl SwpMaximize Code for minimizing a window self primaryWidget osWidget handle winQueryWindow
306. on you will find multiple sample parts that you can run For example you can run MtTravelAgencyMainView There are also parts for browsing videos look for AVI files in the VISUALAG SAMPLES directory and browsing sounds look for WAV files in the same SAMPLES directory 38 VisualAge for Smalltalk Handbook Fundamentals Default Memory Answer Is there a way to change how much memory gets allocated by VisualAge It appears that 2 MB is the default The following will work for Version 2 see page 38 39 of the Smalltalk User s Guide for memory options in Version 3 When you call the packaged image abt exe iMylmage add the following parameters mi500000 This gives the memory an increment of 0 5 MB at a time and is what was defaulting to 2 MB mo5500000 This gives the initial memory allocation to the image As a rough guide take the previous mi figure away from the initial size of the image for example 5 5 MB The full call would then be abt exe iMylmage mo5500000 mi500000 Storing Settings Answer want to be able to store current settings into a file just prior to closing an application The goal is so that next time the same VisualAge application is opened it will provide the user with the same settings as the last access by first reading the file with the settings How would do this One way to do this is by using the objectDumper and objectLoader Create a class called settings which contains all th
307. on is released know how to determine which version of a class is currently loaded in my image but how do determine which version is the released one without having to Load Released and then examine which one responds There are many ways to find out which class version is the released version in an application One way is to browse the application editions From the Application Manager select the application you want then browse the application editions Select the edition you want to see the class versions listed are the released versions VisualAge for Smalltalk Handbook Fundamentals Change Management for Flat Files Answer am using VisualAge for Smalltalk Professional for change management of my Smalltalk code However also have some flat files that are used as part of the product as well metadata and the like Does VisualAge for Smalltalk Professional have any capability to manage these too or am forced to use a different approach for my non Smalltalk product files If your team is comfortable with the VisualAge for Smalltalk Professional version control system there s nothing stop you from saving the contents of those files as Smalltalk comments in some method VisualAge for Smalltalk Professional manages applications classes and methods by storing them in its library file lt also expects the methods to compile under Smalltalk but comments don t have to compile You can easily extract the text of methods a
308. onnect the selectionChanged events to a script but for some reason this script runs only once What would be a way of making this work Chapter 3 Graphical User Interface 105 You ll need to write a script for each toggle button and connect it to the selectionChanged event Here s what the scripts might look like Smalltalk sortByNameSelectionChanged selectionBoolean Sort by name selectionBoolean true ifTrue self subpartNamed SortByName disable self subpartNamed SortByDate clear enable lt perform sort by name statements gt Smalltalk sortByDateSelectionChanged selectionBoolean Sort by date selectionBoolean true ifTrue self subpartNamed SortByDate disable self subpartNamed SortByName clear enable lt perform sort by date statements gt The selectionBoolean value needs to be checked because the statements should only be executed when the menu item is checked not unchecked Disabling Push Buttons on Pop Up Menus Questioni How do disable push buttons on pop up menus You can use a setSensitive method to disable a push button The default setting for the value of the XmNsensitive resource is true This method will allow you to set it to false If you want the push button to be disabled initially try using the createPopupMenu argBlock method When you create a menu through a Smalltalk script you first create the menu and
309. ons 3 comprehensive end to end error processing and 4 a generic application program interface API consisting of structured verbs that are mapped to a product implementation Synonym for Advanced Program to Program Communications Login The account name used to gain access to a computer system Not kept secret unlike password LU type In SNA the classification of a LU LU session in terms of the specific subset of SNA protocols and options supported by the logical units LUs for that session namely The mandatory and optional values allowed in the session activation request The usage of data stream controls function management headers FMHs request unit RU parameters and sense codes e Presentation services protocols such as those associated with FMH usage LU types 0 1 2 3 4 6 1 6 2 and 7 are defined machine readable information MRI Language sensitive information associated with a computer program such as program integrated information or softcopy documentation management services In SNA one of the types of network services in control points CPs and physical units PUs Management services are the services provided to assist in the management of SNA networks such as problem management performance and accounting management configuration management and change management megabyte A million bytes A thousand kilobytes See also byte bit kilobyte message In Smalltalk a commun
310. ook vnet ibm com Please rate your overall satisfaction with this book using the scale 1 very good 2 good 3 average 4 poor 5 very poor Overall Satisfaction Please answer the following questions Was this redbook published in time for your needs Yes No If no please explain What other redbooks would you like to see published Comments Suggestions THANK YOU FOR YOUR FEEDBACK O Copyright IBM Corp 1997 339 Printed in U S A II
311. opment environment you can display a list of all methods in which breakpoints are set and browse the method code from the list Namespaces have been added to the language which give you control over the scope of globals in your application Namespaces allow you to use a language construct that logically groups globals and assigns them a name You can later selectively gain access to and include the collection of globals in the scope of your application by referring to its name Thus namespaces provide the same type of scoping control for globals as application prerequisites provide for class references They also provide an easier to use and more robust technique than was provided by toBeLoadedCode and wasRemovedCode in previous releases A new query tool has been Chapter 1 What Is VisualAge for Smalltalk 17 18 added to the development environment that lets you display all references to objects methods and globals that are outside the scope of your application its namespace references and its prerequisite applications This tool helps you find and correct scoping and namespace problems and correctly prepare your application for packaging especially when using ICs The performance analysis and tuning tools now monitor and collect more memory allocation information and enable you to easily create run and compare the results of performance benchmarks The memory monitor in Version 4 0 now shows individual pieces of allocated me
312. or a reference on available resources check out the standard Motif Xt X11 manuals such as those from O Reilly and Prentice Hall Interface to Windows 95 88 Answer Will VisualAge for Smalltalk provide an interface to Windows 95 integration features VisualAge for Smalltalk is meant primarily as a standard compliance oriented tool For example even though you have the Windows 95 control support in Version 4 strongly suggest that you abandon Windows 95 specific controls in the interest of portability through Common User Access CUA 91 standard compliance VisualAge for Smalltalk Handbook Fundamentals Applications with Multiple Windows Answer How do create applications with multiple windows View Wrappers can be extremely useful when building complex applications with many windows because of the ability to conserve screen real estate in the Composition Editor The View Wrapper performs better than the variable approach because the reusable part is not constructed by VisualAge for Smalltalk until the openWidget connection executes The View Wrapper is essentially an icon that represents another view that you have created Instead of taking up valuable Composition Editor space you can place this icon on the free form surface and make connections to and from it After adding a View Wrapper part to the Composition Editor change its type to the class name of a view that you have already created Since the View Wrappe
313. or more tasks on behalf of a client The server can be a computer a file server a specific process ona server or a distributed object A single server machine could have several different server software packages running on it thus providing many different servers to clients on the network See also client network service 1 A specific behavior that an object is responsible for exhibiting 2 In network architecture the capabilities that a layer and the layers closer to the physical media provide to the layers closer to the end user 3 A set of service primitives that a layer provides to the layer above it service object A nonvisual part that gives access to the outside world of a VisualAge for Smalltalk image session 1 A connection between two application programs that allows them to communicate 2 In SNA a logical connection between two network addressable units that can be activated tailored to provide various protocols and deactivated as requested 3 The data transport connection resulting from a call or link between two devices 4 The period of time during which a user of a node can communicate with an interactive system usually the elapsed time between logon and logoff 5 In network architecture an association of facilities necessary for establishing maintaining and releasing connections for communication between stations 6 A series of CGI queries that come from the same client and belong to
314. orm primaryWidget widget addEventHandler KeyPressMask receiver self selector keyPressed clientData event clientData widget The event handler looks like this Chapter 3 Graphical User Interface 143 Smalltalk keyPressed widget clientData clientData event event key key event keysym key XF10 key XF22 ifTrue self halt key XF9 key XF21 ifTrue self halt The above code is correct but you should take into account that some of the function keys have been reserved for the system For example PF10 on a window with a menu bar will move the cursor to the first menu bar item Hence the debugger window will not come up in the above example Grabbing Typed Words Question When using a multiline edit MLE window would like to grab the words as they are typed The only event saw that looked like it might be of use was the notify on each key stroke If use that l d have to look for a blank and then post a signal that a word has been completed Am missing something Is there a mechanism already there No you are not missing something The MLE does not parse its own text If you are interested in dropping to the widget layer you can also check out the XmNvalueChangedCallback and XmNmodifyVerifyCallback The XmNmodify VerifyCallback is fired before the text shows up when the user has typed a character The XmNvalueChangedCallback is fired after the text has been displayed i
315. ormation titles and optionally the letter or abstract from selected categories To get started send an e mail to announce webster ibmlink iom com The keyword SUBSCRIBE must be the only word in the body of the e mail leave the subject line blank You will receive a category form and listserver details To immediately start your subscription to for example AS 400 announcements put the words SELECT HW120 in the body of the note On the afternoon of an announcement day you will receive e mail with the announcement along with a list of newly available redbook titles To obtain a full abstract of a particular redbook use GET SG242535 in the note VisualAge for Smalltalk Handbook Fundamentals VisualAge Support on CompuServe VisualAge users are encouraged to use CompuServe to ask questions about VisualAge and its features When logged on to your CompuServe account type GO VISUALAGE to get into the BM Workstation Rapid Application Development WRAD conference You will find sections to discuss the following and other VisualAge topics e Installation Begin e Communication Languages e Database AS 400 Connection Web Connection About the Authors This redbook was produced by a team of specialists from around the world working at the International Technical Support Organization San Jose CA Andi Bitterer works as a consultant for the International Technical Support Organization at the Almaden Research Center in Sa
316. orts IBM and non IBM databases and a variety of communication protocols including TCP IP for operation in heterogeneous environments VisualAge for Smalltalk is built on a nonproprietary standards base Smalltalk that can be extended and modified by customers and third party vendors Team or Professional Version Answer Does VisualAge have a team or pro edition Yes VisualAge for Smalltalk actually has two base versions Standard and Professional VisualAge for Smalltalk Standard is for the individual programmer VisualAge for Smalltalk Professional is for individuals or teams and can support a LAN based library of classes and parts version control configuration management and other functions that support collaborative team development Additionally a Professional Server product is available for VisualAge for Smalltalk and IBM Smalltalk The Professional Server extends the box product by providing multiple user access and a central LAN based library of classes and parts that developers can access concurrently Advantages of VisualAge Answer What are the key advantages of VisualAge VisualAge for Smalltalk is the only tool of its class that offers full integration of visual programming object oriented environment and best of breed team support Programmers never need to leave one tool to go to another to build and test a complete application Teams of programmers can easily manage complex object oriented development projects
317. osed to look and work much like a contemporary spreadsheet However we intend to display information in cells that may be several lines long have created an EwTableList widget Within one of the columns use an EwTextEditPolicy passing the editMode as multiple lines Everything works great can enter as many lines as wish The problem have is what occurs when leave the cell The cell displays only a single line of text Ideally would like to expand the edited row to a size capable of displaying the complete text Alternatively would like to allow users to resize rows in the same way they can resize columns have tried messing with temHeight settings but they appear to affect every row within the table l am told that you can create dynamic row heights via setting the temHeight to nil do this in prelnitWindow This feature is undocumented but have it on good authority that it works Setting itemHeight to nil causes the table to base each row height on the data in that row don t think it allows you to have user resizable rows That would probably require subclassing EwTableList itself You might want to trace through the code in EwTableList and its superclasses that deal with itemHeight It is very illuminating If you set the temHeight to nil the EwTableList will send the ewHeightUsing method to the value in each of the cells Your contents are EsStrings therefore they should already pick up the implementa
318. osition Editor a part that can be used as a container for other visual parts such as push buttons workstation 1 An I O device that allows either transmission of data or the reception of data or both from a host system as needed to perform a job for example a display station or printer 2 A configuration of I O equipment at which an operator works 3 A terminal or microcomputer usually one connected to a mainframe or network at which a user can perform tasks World Wide Web WWW W3 the Web An Internet client server distributed information and retrieval system based upon HTTP that transfers hypertext documents across a varied array of computer systems The Web was created by the CERN High Energy Physics Laboratories in Geneva Switzerland in 1991 CERN boosted the Web into international prominence on the Internet List of Abbreviations AIX Advanced Interactive eXecutive APAR authorized program analysis report APPC advanced program to program communication APPN advanced peer to peer networking BMP bitmap CAE Client Application Enabler CDROM compact disk read only memory CG common graphics CGI Common Gateway Interface CICS customer information control system CLI call level interface CORBA Common Object Request Broker Architecture CPI C common programming interface for communications CPU central processing unit CRC class responsibility collaborators CUA Common User Access D
319. ot work the same as Windows and AIX when it comes to event handlers OS 2 propagates messages up the parent tree For example if have a main window with three text fields a drop down list and a spin button and add an event handler to detect key presses to the main window the child widgets also receive those messages and handle those key press events on OS 2 However on Windows and AIX this is not the case the messages are not propagated to all children To get around this you can write Windows or AlX specific code to send the message recursiveDo to your main window and set up the same event handler or callback for all the children the children s children and so forth You probably create a resource hog to do this but its really the only way to achieve this effect on Windows or AlX Note Using recursiveDo will not help you with widgets controls that are composites at the operating system level For example this will not solve the problem on Windows where you can t get pointer motion notification over certain parts of the combo box control From Smalltalk s perspective there is only one view and hence nothing to recurse while there are actually two to three window handles at the operating system level Chapter 3 Graphical User Interface 151 Part Validation Answer How do execute an error script every time a user leaves a part to be validated You must modify the method primCommitUserInput in AbtTextConverterM
320. ource code to find the class name and selector Storing Object of Unlimited Size Answer am using the Swapper the class parent of Dumper and Loader to write my objects to disk I ve heard that you can t write any single object to disk that exceeds 65000 bytes Is there a workaround to solve this The limitation is that no single primitive object can be greater than 64 KB in size Its actually a few bytes less because of object headers Primitive objects that must be less than 64 KB are Strings DBStrings ByteArrays and Arrays Note that each array element is a 32 bit pointer so that an array with 16 1024 elements will exceed the limit because the continguous storage area for the array itself violates the limit The script at the end demonstrates successful storing and retrieving of object collections whose aggregate size is over 4 MB but no single element violates the 64 KB limit If you have a need to store data that contains large primitive objects such as very large strings then you may indeed need to use a commercial database package Optionally if you know where these large objects are and if they aren t too prevalent you could break them up and reglue them yourself You would be the best judge of the appropriateness of this approach Some objects such as Classes and BlockContexts cannot be swapped out If your object graph contains any of these then you will have other problems I believe that sorted co
321. oxy Telnet server performs authentication of the user and then lets the traffic flow through the proxy as if it were not there Function is performed in the firewall and not in the client workstation causing more load in the firewall Compare with socks PRPQ Programming Request for Price Quotation A customer request for a price quotation for a licensed program to be designed 298 VisualAge for Smalltalk Handbook Fundamentals especially for a particular group of customers or an application Documentation for the program is provided only to those customers who order the PRPQ pseudocode An artificial language used to describe computer program algorithms without using the syntax of any particular programming language The code requires translation before execution public class A class that is provided as part of the VisualAge or IBM Smalltalk API A public class is visible to applications other than its containing application Public classes are designed to function with future releases of VisualAge or IBM Smalltalk and with operating systems supported by VisualAge or IBM Smalltalk Contrast with private class public interface A set of external features that enable a part to interact with other parts A part s public interface is made up of three characteristics attributes actions and events Public Interface Editor A VisualAge view used to create and modify attributes actions and events which together make up t
322. page that features a form in the center that will be used to display a GIF file Right above the form is a file picker that returns the path and file name of the graphic the user picked It is basically a recreation of the background image selector on the form part in Web Connection The system fails to update the graphic properly however have torn off the backgroundDescriptor from the form and tied its module name attribute to the output of the file picker When open the page for the first time the image is correct whatever the user selected last time but am unable to get the image to update live Any ideas How can get the updateOperation to fire before the user actually clicks the OK button tried to examine the logic but am stymied by what look like incomplete connection diagrams in the settings view parts The edges are just floating with no apparent sources or targets What can be done to get around this You cannot see the form in the settings page view because the bottom and right edge attachment offsets are zero To fix this do the following Edit the part in question for example AbtIntegerDatatypeSettingsView Normally you would select the form and open its settings page to change the offsets However as you cannot see the form you cannot select it forcing you to change the offsets manually First open an inspector on the partBuilder as follows Press Alt Shift Mouse button 1 anywhere on the Composition Editor T
323. plementation of VisualAge for Smalltalk provides no mechanism for renaming a part once it has been created The copy facility is flawed in that certain connections retain a reference to the previous class name In Smalltalk you can rename a class by filing it out exchanging the names in an editor and filing it back in A little more work must be done in VisualAge even Smalltalk classes with a public interface will not work using the file out file in technique Chapter 2 General Information 31 Solution 1 Open the Composition Editor for your class and select Generate Archival Code from the file menu File out your class and in an editor find and replace occurences of the old class name with the new class name Save the file and then file it into your image An unfortunate side effect of this technique is that the archival code will stay connected to your class forever Whenever you save the part in the Composition Editor you will be asked if you want to regenerate archival code Solution 2 Create a new visual part In the new part dialog change the superclass to the name of your existing class When the Composition Editor editor opens make a small change move some widget a bit to enable the Save menu item and save the part This generates the magic abtBuildinternals method and all the invisible stuff needed Change to the Script Editor In the class definition change the superclass from the name of your old part to AbtAppBldrV
324. plication Try this Smalltalk EmClassDevelopment imageBuilder loadApplications OrderedCollection new add lt App Name gt yourself Loading Previous Editions of Application Answer Is there a fast way to load all recent class editions of the entire application Each time when I get a native image from the server and don t create a new version of the application in advance have to load the last edition of all classes manually Is there a faster way of doing this One way you can manage your code so that the transition to a new image is less painful is to create a configuration map pointing to the application editions you are interested in If you do this you can load in all your applications with one operation Deleting an Application Answer Can if have installed VisualAge for Smalltalk Professional delete an application by simply selecting delete from the applications menu on the organizer Deleting really just deletes an application from a configuration map it does not delete the application from the library If your application is not yet associated with any configuration map the best you can do is unload it from your image and try to forget it exists Creating a new application does affect the library manager Unfortunately there is no way to remove your application from the library except to purge your application and clone the library Another way would be to start with a new manager and i
325. presents a request for system action comment A set of characters enclosed in double quotation marks Smalltalk ignores comments and does not execute them Common Gateway Interface A standard protocol through which a Web server can execute programs running on the server machine CGI programs are executed in response to requests from Web client browsers Glossary 283 Common Object Request Broker Architecture CORBA An architectural standard proposed by the Object Management Group OMG an industry standards organization for creating object descriptions that are portable among programming languages and execution platforms Common Programming Interface Communications CPI C An IBM communications architecture that defines a programming interface for peer to peer communications that is common across different environments and platforms Also referred to as CPI Communications or CPI C Common User Access CUA An IBM architecture for designing graphical user interfaces that uses a set of standard components and terminology component A functional grouping of classes and related files within a product See also system component composite part A part that contains other parts it can also contain data and behavior of its own For example a user interface view is a composite part composed of subparts such as entry fields push buttons and text Composition Editor In VisualAge a view that is used to build a graphic
326. psing its parent Is there a work around to keep a child selected once its parent is collapsed Chapter 3 Graphical User Interface 121 122 The philosophy of the tree views is that the children do not exist in the container unless they are displayed The reason for this philosophy is that the container may contain a large number of items that have children that have children that have children To optimize the tree views for performance we do not hold onto the children and they change from collapse to expand that is why we request them each time an item is expanded Because they do not exist for the container they are removed from selection when the item is collapsed Smalltalk addNotebookPage aNotebook named aName page label aNotebook subpartNamed aName put page AbtPortableNotebookPageView newPart page framingSpec AbtViewAttachmentConstraint new leftEdge AbtEdgeConstant new offset 34 topEdge AbtEdgeConstant new offset 90 page subpartNamed label put label AbtLabelView newPart label object Time now printString framingSpec AbtViewAttachmentConstraint new leftEdge AbtRunEdgeAttachmentConstraint new attachment XmMATTACHFORM offset 65 rightEdge AbtRunEdgeAttachmentConstraint new attachment XmMATTACHNONE topEdge AbtRunEdgeAttachmentConstraint new attachment XmATTACHFORM offset 95 bottomEdge AbtRunEdgeAttachmentConstraint new attachment XMATTACHNONE page openW
327. ption doesNotUnderstand 228 Creating Classes from Smalltalk Script 0 lt 229 Keyboard Event Handler aaa aaa 230 Changing Object Class o 231 Cleaning Up the Image 0 0 000002 eee 232 Finding Methods Containing a String 232 Free Disk Space uti e edn foe de Bote eho OE bd el da 233 Using LookupTable Instead of Dictionary 234 Concatenation and Streams 0 0000005 2s 237 Contents Xi xii Comparing Floating Point Values 2 239 Immutable Objects and Identity Objects 2 2 240 Chapter 5 ENVY 3 25 03 hi 540542 e 0074942544253 Lax 243 Working with the Team Environment 243 Shared Library Password Protection 244 LI Drartes ata ithe eat ake de hy ye Monee E ede ete ek tado a 244 Import and Export sek pda A eke Die ee BS eh A 245 Loading Applications 0 002200 20008 245 Moving Components Between Libraries 246 Archival Code nic heb eh ado de dn a pe hd a eek A a dd 246 Identifying the Released Version 246 Change Management for Flat Files 247 Date Stamp for Versioned Classes 247 Applications and Subapplications 248 Connecting to a Cloned Library 0 0 e 248 Reloading an Application 0 0
328. quenceableCollection and all its subclasses implement the reverse method Something that looks and sounds simple is not turning out to be simple at all am dealing with a string in the following format lastName firstName midInitial From this string want to create a new string that contains only the lasiName but can t figure out how to do this 186 VisualAge for Smalltalk Handbook Fundamentals caine many ways to unpack a string One way to get the lastName is the Smalltalk str array lastName initial str Doe John A array str subStrings lastName array at 1 initial array at 3 Implementation of become Questioni How efficient is become in IBM Smalltalk Version 3 had thought that it was all done internally by placing a proxy for the new object in the same memory address as the old object so that the garbage collector then removed these proxies the added level of indirection is temporary However someone has suggested that this may not be true Apparently Parkplace does it this way but Digitalk doesn t and their implementation is not very efficient Anyone know anything PUMA can t answer your question for sure but here is some information on become Once Smalltalk implementations had an object table Object pointers were indexes into the table A become was simply a swap of two pointers in the object table It was fast and symmetrical But object tables were of f
329. r 2 2n5 each esnet eh ed bale ake Adee See eee 112 Identifying Last Selected Item 2 02 0 0 112 Default Action Requested 0 020000 022 ee 113 Combo Box Behaviour 0 0000 0 pee ee 114 Skipping through a Notebook 0 2 0000 114 Bitmap on Notebook Tab 0 020000 0 24 115 Hiding and Showing Pages 0 2 0000 pene 116 Porting Notebooks across Platforms 117 Navigating between Columns 0 117 Selecting Valid Items 00 0000 a 117 Validating Input Fields 0 0 0 0000000000 118 Container Column List Box 2002000200000 5 119 Columns with GUI Elements 2 0000 119 Adding Records to Container aaa aaa aa 120 Changing babels sen 2 fot el te dd Bog Je ote A ed el Sa 120 Deselecting Details Tree Items 121 Resizing Container Columns 0 2 000 000 0 50s 123 Contents Vii viii Changing Scroll Bar Size o 124 Container Details Tree Children 0 0 e 124 Hiding the Heading on a Container Details View 124 Disabling a Notebook Tab 0 00 0000000 125 List with Icon Column 2 2 125 Hiding GOMA tac n A eee a eee Bae GA Boe BB pe 125 Removing an Icon 2 a a 125 Adding Icons Dynamically 0 2 02000 0004 126 Refreshing a Container Details View
330. r is a place holder for a view you make connections to it as if it were the actual view class Exit Dialog Message Box Answer l am attempting to create an exit dialog message box that prompts the user to respond to the question Are you sure you want to exit when they either select Close from the system menu or double click on the system menu Create an event to script connection from closeWidgetRequest of the window to the following new script Smalltalk okayToClose aDoit aDoit doit true System confirm Are you sure you want to exit Chapter 3 Graphical User Interface 89 Window Location Questioni How do specify where my window will appear on the screen when open There are two ways to do this if your window is a visual part e Think of the free form surface of the Composition Editor as your display if your window is at the top left of the free form surface it will be at the top left of your display e Assuming that you want to place it specifically at test or run time and not affect its position in the Composition Editor you could connect from aboutToOpenWidget of the window to a script like the following Smalltalk self subpartNamed Window yourself primaryWidget x 200 y 400 Also you could use the view s finalInitialize method to do something like the following Smalltalk finallnitialize self initWidgetSize self computeSomeSizeAndPositi
331. r number e Credit card number Credit card expiration date Card issued to Signature We accept American Express Diners Eurocard Master Card and Visa Payment by credit card not available in all countries Signature mandatory for credit card payment How to Get ITSO Redbooks 277 278 VisualAge for Smalltalk Handbook Fundamentals Glossary A abstract class A class that provides common behavior across a set of subclasses but is not itself designed to have instances that work abstraction A simplified description or view of something that emphasizes characteristics or purposes relevant to the user while suppressing details that are immaterial or distracting accessor methods Methods that an object provides to define the interface to its instance variables The accessor method to return the value of an instance variable is often called a get method or getter method and the accessor method to assign a value to an instance variable is called a set method or setter method access plan The control structure produced during compile time that is used to process SQL statements encountered when the program is run action In VisualAge a function or operation that a part can perform upon receiving a message Actions enable a part s public interface to give other parts access to its behaviors Compare to event and attribute activate To make a resource of a node ready to perform the functions for which it was desi
332. r other than icon push buttons Working with icon push buttons is the only case where by default a hover help tag is displayed Entry fields for example have no string resource to use as a default hover help tag In these cases you need to hook the pop up callback and provide the hover help string to be displayed in the callback data The widgets not supported for hover help are those that do not signal mouse moves such widgets are platform dependent For example on some platforms drop down list boxes do signal mouse moves when the pointer is Chapter 3 Graphical User Interface 157 over the drop down button but do not signal mouse moves when the pointer is over the text portion of the drop down list On those platforms hover help is not supported for drop down lists There currently is no list of unsupported widgets since whether the widgets signal mouse moves depends entirely on the operating system s implementation of the control Improving Performance Tip In order to improve performance with our application which uses many complex notebook objects and to help with memory utilization we implemented an approach that hides existing visual objects rather than the closeWidget approach When the application needs to open a notebook we iterate through existing instances of the visual class and show them rather than issuing an openWidget event This has had a dramatic performance improvement in our application making it p
333. rag and drop 129 event handler 151 explorer 260 for Workgroups Vol2 203 installing on DBCS system 267 logo 15 maximize window 91 moving library to AIX 255 notebook 117 Personal Communications Vol2 37 router Vol2 4 sharing files Vol2 24 WinSock Vol2 65 Windows 3 1 MQ client Vol2 79 Windows 95 as distributed server Vol2 222 client 83 controls 88 DB2 support Vol2 165 local name server Vol2 222 Netware server 257 requester 83 sizing toolbar 259 TreeView 259 Windows NT client 84 WinSock Vol2 65 WordPro 260 work station controller ASCII Vol2 4 work station function Vol2 10 Vol2 21 workspace packaging 48 wrapper COBOL Vol2 98 initializing 146 legacy code 9 object 206 PM control Vol2 94 SOM Vol2 240 Vol2 245 view 89 writing stack trace to file 29 WSI server Vol2 254 Index 337 X Xx resources 88 server 74 X3 Project 986 D 166 XmNmodifyVerifyCallback 144 XmNvalueChangedCallback 144 XmOPEN 260 Y year format 212 338 VisualAge for Smalltalk Handbook Fundamentals ITSO Redbook Evaluation VisualAge for Smalltalk Handbook Volume 1 Fundamentals SG24 4828 00 Your feedback is very important to help us maintain the quality of ITSO redbooks Please complete this questionnaire and return it using one of the following methods e Use the online evaluation form found at http www redbooks com e Fax this form to USA International Access Code 1 914 432 8264 Send your comments in an Internet note to redb
334. reads HTML tags and you might consider doing something similar for your own browser Chapter 2 General Information 43 Loaded Method Answer Is an application s loaded method invoked when it is run as an executable Do you need to do anything special if you want to ensure that it will be run The loaded method is a class method called only when the class is loaded into the image Its usual purpose it to complete the task of hooking the class into the environment and setting up class variables and such It is not called at execution time Missing Character Set Answer What should do if get a missing characterSet translation table iom NNN error You need to customize the ABTRULES NLS file to include the 862 code page Do this by copying and pasting all 862 code page table definitions from ABTRULES ALL file to ABTRULES NLS This is a null table that doesn t really do anything Eventually you will need a table with the proper values if you really want code page translation to work for your system Event Triggering 44 Answer created a Smalltalk class and defined in it an event in its public interface In this class have only one method that signals this event under a certain condition However when running the code this event is being fired and am pretty sure didn t fire it Tracing the code in the debugger reveals that VisualAge has a collection of Abt Spec and it is firing the event from thi
335. reate a nonvisual part for which you don t need composition facilities you can subclass AbtPart instead of AbtAppBldrPart Cleaning Up Unused File Handles 208 Answer If you get a walkback while you have a file open that file remains open until you exit the image Is there a way to clean up all of these open files The best way to address this situation is to act defensively You can set up an exception handler so that when a walkback occurs the file handles are automatically closed Here is an example Smalltalk inputFile stream tempString sre E inputFile CwFileSelectionPrompter new title File to open prompt stream CfsReadFileStream open inputFile stream isCfsError ifTrue self error stream message stream atEnd whileFalse tempString tempString stream next asString stream close whenExceptionDo stream close empString VisualAge for Smalltalk Handbook Fundamentals Initializing Class Variables Answer How can you initialize class variables in the Trailblazer would like to initialize a class variable with a pool dictionary Probably toBeLoadedCode would be the best place This string is stored with the application in the manager and is evaluated compiled when the application is loaded Since it is evaluated before any of the application s classes are loaded you can define pool dictionaries that are referenced in the application s classes
336. required for my run time image There s a little script to scan the messages during packaging and show you catalogs your code referenced That s the minimum set of cat files you need to distribute By the way most nonerror items are bound to the image using the CAT entries from the development environment English These files are needed if the locale changes because it is on a non US machine or a run time error occurs See EsPoolDictionary gt gt indexedMsg for details VisualAge for Smalltalk Handbook Fundamentals Smalitalk stream tokens file file CwFileSelectionPrompter new title Packaging Messages prompt file isNil ifTrue nil stream CfsReadFileStream open file stream atEnd whileFalse tokens stream nextLine subStrings tokens size gt 0 and tokens at 1 indexOfSubCollection NlsCat startingAt 1 gt 0 ifTrue Transcript cr show References messages in Smalltalk at tokens at 1 asGlobalKey at CATALOGNAME stream close Packaging Pool Dictionaries Question How can tell the packager not to change my pool dictionaries when creating a run time image To prevent the packager from changing your pool dictionaries add the following class method to your class application Smalltalk packagingRulesFor aPackagedlmage Pack the NLS pool aPackagedlmage includeGlobal MyClassPool Question I m having difficulty g
337. requisite application s classes In team development prerequisite applications are particular versions or editions of applications presentation layer In the Open Systems Interconnection reference model the layer that provides for the selection of a common syntax for representing information and for transformation of application data into or from this common syntax primary logical unit PLU In SNA the logical unit LU that contains the primary half session for a particular LU LU session Each session must have a PLU and secondary logical unit SLU The PLU is the unit responsible for the bind and is the controlling LU for the session A particular LU may contain both primary and secondary half sessions for different active LU LU sessions primary part In a composite part constructed with the VisualAge Composition Editor the subpart whose public interface is fully exposed on the public interface of the composite part The primary part is transparently visible to parts outside the composite part and is the subpart with which most interaction will take place private class In VisualAge or IBM Smalltalk a class that is not part of the system API but is provided as part of the internal functioning of the system A private class is not visible outside its containing application If you use a VisualAge or IBM Smalltalk class marked as private you might have to modify your code in Glossary 297 order for it to work with a f
338. rfaceSpec calculatePartBuilder You should also have some class private builder methods Do you see any of these methods Open a browser on the archival application Do you see class names for all your visual parts When you generate archival code for your visual parts the class gets extended in the archival application The class extensions are the archival code methods If you don t have the archival code methods suggest you go back and regenerate the archival code file it out and then file it back in Meaning of Application Errors Answer Where or how can find an explanation of the fatal application errors From the System Transcript display the following code Smalltalk SystemPrimitiveErrors keyAtValue errorNumber If for example you highlight and display this statement with argument 33 you get the following result PrimErrlmageFileOpenError 68 VisualAge for Smalltalk Handbook Fundamentals Error Undefined Object does not understand messageString Question get the following error every time try to save a part Undefined Object does not understand messageString How can correct this Inspect AbtShellView the class You can do this by executing Smalltalk AbtShellView inspect From the inspector double click on the entry classPool This should open a Dictionary Inspector with two entries AbtinlmageRestore and InLongOperation Select the ent
339. riables 225 invisible 45 load editions 249 loaded method 44 locale 210 264 manager 66 method 175 methods at run time 206 missing 52 missing SOM definition Vol2 243 model 65 naming 226 naming convention 63 ObjectDumper 39 217 ObjectLoader 39 217 OSHab Vol2 88 OSHps Vol2 88 OSObject Vol2 81 Vol2 95 OSObjectPointer Vol2 81 OSWidget 74 225 owner 256 packaging modifications 49 PlatformFunction Vol2 95 recompiling 169 RECORD Vol2 3 Vol2 48 released version 246 renaming 29 31 reusing 63 Index 311 312 class continued SequencableCollection 218 SequenceableCollection 186 session Vol2 114 sharing instance across object spaces Vol2 207 SortedCollection 218 specifying policy 57 string 186 Swapper 217 SymbolTable 226 testing 173 Time Vol2 19 unreleased 257 updating attributes 205 variable 173 variables initializing 209 with instances deleting 35 XPlatformAdministration 87 CLI Vol2 120 Vol2 166 Vol2 193 client concurrent processes Vol2 39 MQ Vol2 73 OS 2 optimized Vol2 21 passing data Vol2 36 run time access Vol2 218 socket Vol2 68 transaction abend Vol2 72 unsupported 61 Client32 83 ClientAccess 400 32 bit optimized client Vol2 7 advanced connection Vol2 59 AS 400 database Vol2 11 ODBC Vol2 45 Vol2 48 Vol2 135 ODBC driver Vol2 5 ODBC requirements Vol2 7 opening automatically Vol2 59 optimized for OS 2 Vol2 50 router Vol2 37 status Vol2 17 TCP IP Vol2
340. ring Disable the button if the string is empty otherwise enable it self subpartNamed Button enabled aString notEmpty Accelerator Keys Answer am trying to use accelerator keys for some menus that would like to have in my application Is it possible to use accelerator keys for menu items Defining accelerator keys is not supported for menu items in pop up menus They are supported only for menu items in the menu bar The underlying reason is because pop up menus are not created until the user clicks the right mouse button and this would be when the accelerator table gets created The accelerator table then gets destroyed when the pop up menu goes away In effect if you have defined accelerator keys for a menu item in a pop up menu and hit for example Ctrl V the menu has not been created so the event does not get signaled If it would be appropriate in your application you could design duplicate menus in your menu bar with accelerator keys defined for each pop up menu you have That is how we have dealt with this in the development environment Hover Help on Widgets Answer Is it possible to get hover help for push buttons entry fields and table cells as well as simple icons The documentation implies hover help works for icons only The underlying support for hover help is implemented as an extended widget and can be used for all widgets that support mouse move callbacks Thus hover help does work fo
341. rmal operation of its user interface To overcome this problem VisualAge enables you to reroute the execution of any external functions to a separate thread so that normal processing can continue while the function is running VisualAge for Smalltalk Handbook Fundamentals Global Variable Answer How do create a global variable Since the names of global variables are nothing more than keys in the Smalltalk dictionary a new global variable is added by adding a new key to this dictionary The global variable should begin with a capital letter For example the following statement adds a new global variable called MyCustomers with a value of nil Smalltalk Smalltalk at MyCustomers put nil If you subsequently want the variable just execute Smalltalk MyCustomers lt value gt Even with this method you have to be very careful that MyCustomers is not already an existing global for example a class or you may break the system Avoid the use of global variables in applications if at all possible The use of global variables violates the principle of data encapsulation Many times adding a new object or adding behavior to an existing object will provide the same function as a global variable Updating Class Attributes in a Run time Image Answer If a user modifies the value of a class attribute in a runtime image is the change automatically saved from one execution to the next In other words
342. rnishing of this document does not give you any license to these patents You can send license inquiries in writing to the IBM Director of Licensing IBM Corporation 500 Columbus Avenue Thornwood NY 10594 USA Licensees of this program who wish to have information about it for the purpose of enabling i the exchange of information between independently created programs and other programs including this one and ii the mutual use of the information which has been exchanged should contact IBM Corporation Dept 600A Mail Drop 1329 Somers NY 10589 USA Such information may be available subject to appropriate terms and conditions including in some cases payment of a fee The information contained in this document has not been submitted to any formal IBM test and is distributed AS IS The information about non IBM vendor products in this manual has been supplied by the vendor and IBM assumes no responsibility for its accuracy or completeness The use of this information or the implementation of any of these techniques is a customer responsibility and depends on the customer s ability to evaluate and Copyright IBM Corp 1997 269 270 integrate them into the customer s operational environment While each item may have been reviewed by IBM for accuracy in a specific situation there is no guarantee that the same or similar results will be obtained elsewhere Customers attempting to adapt these techniques to their own e
343. roblem 72 VisualAge for Smalltalk Handbook Fundamentals 2 Is the user still on Version 3 0 If so suggest that they upgrade to Version 3 0a In the meantime you could send them a replacement for ABT EXE to bring it up to the Version 3 0a level 3 Does the trap occur when bring up a Version 3 0a image with database features loaded Have the customers saved their image with a database connection open If so suggest that they reload into a clean image and not save with open database connections There is a problem in database with finalization code that is trying to free operating system objects that have bogus memory pointers at startup If these don t help and if the SYS317x occurs based on a repeatable scenario then we can turn the problem over to OTI support after verifying that it can be recreated if the customer supplies a a scenario for recreating the failure b the failing image and c any associated files DLLs and the like needed to recreate the failure Error Primitive Error Codes 52 through 55 Tip Primitive error codes 52 through 55 indicate a general protection fault or trap They are described in the table at the end of Chapter 11 in the BM Smalltalk Programmer s Reference These error codes were introduced in Version 3 0a The specific meanings are 52 General Protection Fault 53 General Protection Fault read from invalid memory location 54 General Protection Fault write to invalid memory
344. rowser 1 A window that supports one or more programming activities such as creating new classes or methods modifying existing classes or methods or viewing library members 2 Software that enables users to browse through the cyberspace of the World Wide Web See also Client URL WWW buffer 1 A portion of storage used to hold input or output data temporarily 2 A routine or storage used to compensate for a difference in data rate or time of occurrence of events when transferring data from one device to another byte A set of bits that represent a single character Usually there are 8 bits in a byte sometimes more depending on how the measurement is being made C cascaded messages Multiple messages sent to the same receiver object The messages are separated by a semicolon category 1 On the VisualAge Composition Editor a selectable grouping of parts represented by an icon in the left most column 282 VisualAge for Smalltalk Handbook Fundamentals Selecting a category displays the parts belonging to that category in the next column over 2 A logical association of a group of methods within a class with a name assigned by the class developer CGI Link A stand alone executable program that receives incoming CGI requests and routes them to the VisualAge application CGI Link runs on the HTTP server which does not have to be the same as the machine running the VisualAge application CGI Link s
345. rrors as in this code snippet Smalltalk i do each each become nil when ExError do signal System message signal argument signal exitWith nil This code is interesting in many ways You may want to play with it for some time for example try to initialize to something that does or does not understand do and also try to exitWith something a little more interesting than nil VisualAge for Smalltalk Handbook Fundamentals Of course instead of catching all exceptions you can create the new exception for doesNotUnderstand and change the method to signal that exception instead Creating Classes from Smalltalk Script Questioni What s the proper way to create a class in Smalltalk code the name is entered in an entry field and adding a few methods I m running in the team environment I ve tried various combinations of Compiler gt gt evaluate and Compiler gt gt compile in but have the following problems 1 The class create has no owner No biggie but thought that EmUser currentUser would own classes created with evaluate 2 Methods compile seem to lose their source code stole the code from the SubApplication class method for creating the method for starting run time views don t remember the method name so don t see what I m doing differently Could have something to do with the ownership question though see you enjoy this kind of fooling with the e
346. rrows as in the multimedia support and connect those buttons to the different scrolling events on the container details view Container Details Tree Children Answer Can you use a derived attribute for the children of the parent in a ContainerDetailsTree There is a limitation in container tree view You need to ensure that the children of a parent are identical each time they are accessed otherwise the tree will refuse to expand In other words you cannot use a derived attribute for the children of the parent where there is the possibility that at different times the children of the parent will not be identical objects Instead the first time you get the children of the parent you need to store them in an instance variable of the parent so the next time the parent is asked for its children it returns precisely the same children as it did last time This of course precludes the children from ever changing The problem comes about because the tree view checks the children it had last time when it does the expand operation and if the current children are not the same as the previous children it assumes that the previous children have been deleted and does not expand them Hiding the Heading on a Container Details View 124 To disable the heading of a container details view make a connection from the column s aboutToOpenWidget event to the column s heading action This must be done for every column but it works I
347. rsion 3 0 dynamic SQL was used for all database access IBM s DB2 static SQL essentially allows you to compile your SQL statements and store them in the database What is stored is called a plan which contains optimized database access and manipulation code to execute your SQL statements Comparing static SQL and dynamic SQL is very similar to comparing compiled and interpreted programming languages Static SQL gives you compiled optimized high performance database access while dynamic SQL is in some cases slower to execute but more flexible and easier to change The Version 4 0 database support enables you to create test and debug your DB2 based Smalltalk application using dynamic SQL VisualAge for Smalltalk Handbook Fundamentals and then flip a switch and convert it to static SQL Thus you have the rapid application development style of an interpreted environment early in the development cycle and the speed of a compiled environment when you roll your database application out into production Dynamic and static SQL can be used in combination in the same application allowing you to stage or phase in your cutover to static The performance gains you will realize when switching to static SQL vary and are application dependent Database security for any application that uses static SQL is vastly improved over dynamic SQL For users to execute dynamic SQL he must have complete authority to the tables and data affected by the query T
348. run time A variable by itself contains no data or program logic it must be connected in such a way that it receives runtime identity from a part elsewhere in the application version In the VisualAge or IBM Smalltalk team programming environment an edition of a software component that cannot be changed Each version has a version name Contrast with edition view A composite visual part A view can display and change the underlying nonvisual objects of an application In VisualAge views are both the end result of developing an application and the basic unit of composition of user interfaces Compare to visual part Glossary 303 Virtual Storage Access Method VSAM An access method for direct or sequential processing of fixed and variable length records on direct access devices The records ina VSAM data set or file can be organized in logical sequence by a key field key sequence in the physical sequence in which they are written on the data set or file entry sequence or by relative record number Virtual Telecommunications Access Method VTAM An IBM licensed program that controls communication and the flow of data in an SNA network It provides single domain multiple domain and interconnected network capability visible class A class that another class can subclass or refer to by name in a method Visible refers to the scope in which the class name can be used For a class in a given application visible classe
349. ry called InLongOperation If it says true then change it to false and save using the pop up menu the change If false appears in the right pane then you have a different problem Error on Saving a Part Question When try to save a part get an error that states that there is no primary part why This can happen assuming the following order of actions 1 Open a new part the default window is the primary part 2 Add for example a notebook the default window is still the primary part 3 Delete the window no primary part From here an attempt to save will generate a warning until you specify which part is to be the primary one However if the order is the following the result is different 1 Open a new part the default window is the primary part 2 Delete the window no primary part 3 Add the notebook the notebook becomes the primary part From here saves works fine Chapter 2 General Information 69 In summary if the primary part is deleted VisualAge makes no assumptions about which part should now become the primary one If however you add a new part when no primary part is currently defined the newly added part becomes the primary part It must be a visual part when editing a view class otherwise the primary part will stay undefined The rationale for automatically setting a primary part when one is not currently set is to simplify the typical scenario where one wants to substitute the w
350. s 2 0 0 048 260 VisualAge for Smalltalk Handbook Fundamentals Free Disk Space on Windows Platform 261 Chapter 7 National Language Support 263 Code Page Support 263 Code Page and MPR Problems 263 Required CAT Files wc fe aac ee pee A DP A Se eae amp 264 Decimal Point Representations 264 Using Multiple National Languages 265 Adding French Characters to English 265 Problems with National Language Support in Version3 266 Code Page Conversion between OS 2 and Windows 266 Double Byte Character Set o 267 Appendix A Special Notices 269 Appendix B Related Publications 271 International Technical Support Organization Publications 271 Redbooks on CD ROMs 200 0250 040 272 Other Publications 2 0 2 0200 0000000000000 272 How to Get ITSO Redbooks 4 275 How IBM Employees Can Get ITSO Redbooks 275 How Customers Can Get ITSO Redbooks 276 IBM Redbook Order Form 2 2 2 2 0 0000000 277 Glossary cua ica A lawl 4 oe ed do er hs a Behe al the dink 279 List of Abbreviations 2 2 2 200220 02 305 O xh eee ees Ee ee EE A eh ee ee eee BES 307 ITSO Redbook Evaluation 2 a 309
351. s 2 0 0 54 High Performance Trace Logging 0 02004 54 Closing a DLL from Smalltalk a 55 Unloading When Instances Exist 2 56 Testing When Looping Walkbacks Occur 56 Quickly Disabling Methods 0 0 0 56 Specifying Public or Private with TrailBlazer 57 Browse and Find in the Pop Up Menu 57 Versioning Applications Not Owned 2 2 61 Client Not Supported 2 200000 000000000 61 AbtHeCOrd tira Ba AAS BE PAA BES A Beka oo bee Ae 62 Indexed Message Editor 2 0 025200204 62 Corrupted MRIMFIIG uv sa Be Re a SR Re ee Bele 63 Class Naming Convention 2 0 20 00 0000 63 Category Naming 2 000000 00 2 2 ee 66 Archival Code is Missing 2 0000002 epee 68 Contents V vi Meaning of Application Errors Error Undefined Object does not understand messageString Error on Saving a Part aaa aaa Inappropriate VisualAge Icon Double Execution of Script Error 208 2 asia Sa te Ye nit eck aa A See oie 3 Removing Elements from a View Class EmLibraryStatistics 0 020 Error rE T2 ata e bee eae Se De ee tint ele Errors SYS812X ubica a da 4 we ete SAS ad bol a Error Primitive Error Codes 52 through 55 Error Does
352. s Smalltalk delay numberOfPages delay Delay forSeconds 2 numberOfPages self subpartNamed PMNotebook1 components size 2 to numberOfPages do i self subpartNamed PM Notebook1 currentPagelndex i delay wait Bitmap on Notebook Tab Answer Is it possible to display a bitmap on the tab of a notebook page And if so how do you do this If you would like to have a bitmap appear on the tab of a notebook page you can use the tabContents attribute for the notebook page It is looking for an AbtBitmapDescriptor Here is a piece of sample code that puts a bitmap on the tab of a page Connect the aboutToOpenWidget event of the window to the following script Smalltalk bitmapTab bitmap bitmap AbtBitmapDescriptor new moduleName AbtBmp20 id 101 baseGraphic self subpartNamed NotebookPage tabContents bitmap It is also a good idea to free the bitmap after you are done using it Use of the baseGraphic and the gpiDeleteBitmap see below methods is highly platform specific The way would go about doing this is to assign an instance variable to the baseGraphic in the bitmapTab method and connect the following script to the closeWidget event of the window Chapter 3 Graphical User Interface 115 Smalltalk bitmapFree instanceVariableName gpiDeleteBitmap This causes resources used up by this bitmap to be freed when this window is closed
353. s Versioning Applications Not Owned Tip If you make changes to a class that is in an application you do not own it can be difficult to version and release the application Here s the incantation which assumes that you do not have password control of user IDs or know the passwords 1 2 3 Open the Application Manager Select the troublesome application Select the open editions of the class or classes The owner of that change will be highlighted in the user list in the Application Manager Double click on the highlighted name to change the user to that person Click the right mouse button over the class list and select Version gt Name each One name or Use defaults This will version the classes Now you need to release them Double click on the name list to change the user to the manager of the application name with the gt next to it Click the right mouse button over the class list and select Version Release All gt select Name each One name or Use defaults This will version and release all the classes some of which may already have been versioned Another way to do this is to just select the classes that have not been released yet marked with a gt click with the right mouse button to open the menu and select Release When all classes in the application are versioned and released change the user to the the manager and version the application Client Not Supported Tip
354. s a string used as a name within the system A symbol literal is a sequence of characters preceded by the pound sign with no embedded blanks such as George or messageSelector synchronous 1 Pertaining to two or more processes that depend on the occurrences of a specific event such as common timing signal 2 Occurring with a regular or predictable timing relationship system In data processing a collection of people machines and methods organized to accomplish a set of specific functions system component A component that manages storage of code and access to that stored code A library file is a system component that stores and manages code A user object is a system component that represents a person who can use a library system object model SOM An object structured protocol that enables applications to access and use objects and object definitions regardless of the programming language created that them with no need to recompile the application systems management The process of monitoring coordinating and controlling resources within open systems 302 VisualAge for Smalltalk Handbook Fundamentals Systems Network Architecture SNA The description of the logical structure formats protocols and operational sequences for transmitting information units through and controlling the configuration and operation of networks T TCP IP Transmission Control Protocol Internet Protocol The bas
355. s collection Is it the design of VisualAge or am not defining the event correctly do not want the event to be triggered unless use the signalEvent method Since this is a Smalltalk class that is a subcass of Object as opposed to AbtObservableObject or AbtPart you may want to look at the method featuresAffectedByAction In order to handle classes that normally don t signal events in all cases this method defaults to signal all events for any action To change this behavior override the method to indicate exactly which attributes should be signaled for a given action VisualAge for Smalltalk Handbook Fundamentals Part not Visible Answer What does it mean for a part to not be visible from an application If you get a message about some class not being visible it means that you are either trying to extend or subclass it in an application that does not prerequisite the application containing that class Removed Class Answer got the following debug message from a script Removed Class ClassName does not understand method What did do wrong and how can solve this problem This problem in VisualAge is caused by deleting a class without removing all method references to it You should be able to do Browse References and find all the references to the class that no longer exists if you deleted then recreated the class simply recompile the methods referencing it If this does not work for
356. s platform Sizing the Windows 95 Toolbar Tip The Windows 95 toolbar sizes improperly at run time potentially covering other visual parts To work around this problem adjust the framingSpec of the tool bar so that its bottom edge is attached to another widget This will prevent the toolbar from covering other widgets A fix for this problem is available in the downloadable update Windows 95 TreeView Tip The Windows 95 TreeView traps the collapse and expand events but does not properly signal the corresponding VisualAge events Therefore connecting to the itemExpanded or itemCollapsed event of the TreeView does not work The AbtCwTreeView methods below correct the problem Smalltalk collapseNode aWidget clientData clientData callData callData Private The node collapse callback was called self signalEvent itemCollapsed with self partForNode callData value Smalltalk expandNode aWidget clientData clientData callData callData Private The node expand callback was called self signalEvent itemExpanded with self partForNode callData value As an alternative you can register Smalltalk callbacks in your parts to handle the itemExpanded and itemCollapsed events Use code like that shown below Copyright IBM Corp 1997 259 Smalltalk widget addCallback expandCallback receiver self selector expandNode clientData callData clientData nil widget addCa
357. s Tivoli family of system management products helps you deploy monitor update and manage software applications in your enterprise Tivoli Connection provided in the base includes two facilities for enabling the development of VisualAge for Smalltalk applications that are management ready for Tivoli The first is a set of parts that enable you to easily build an application that generates events and sends them to the Tivoli Enterprise Console The new parts are available on the parts palette Chapter 1 What Is VisualAge for Smalltalk 21 22 when you install Tivoli Connection The parts allow you to instrument your application with events that communicate information about the status and health of your application For example you can send events that identify the startup and shutdown of tasks and the occurrence of error conditions These events are sent to the Tivoli Enterprise Console which provides centralized monitoring and management of system information and events The second facility is a stand alone program the Tivoli Developer Kit that enables you to define the management characteristics of your application to the Tivoli Management Environment The Developer Kit assists you in defining management information about your application by using Tivoli s Application Management Specification You can specify your application s components dependencies distribution and installation details and operational tasks that are needed by th
358. s and class methods of the defining class and its subclasses can directly reference this data Changing the data in one class changes it for all of the other classes Contrast with class instance variable client A software program that is used to contact and obtain data from a server software program on another computer often across a great distance Each client program is designed to work with one or more specific kinds of server programs and each server requires a specific kind of client A Web browser is a specific kind of client See also browser server client object An object that requests services from other objects client server The model of interaction in distributed data processing in which a program at one location sends a request to a program at another location and awaits a response The requesting program is called a client and the answering program is called a server code page A font component that associates code points and character identifiers A code page also identifies how undefined code points are handled collection 1 In Smalltalk a set of elements in which each element is an object 2 In SQL a set of objects created by the SQL 400 licensed program that consists of and logically classifies a set of objects such as tables views and indexes command 1 A request for performance of an operation or execution of a program 2 A character string from a source external to a system that re
359. s include e All classes defined in the same application All public classes defined in any subapplication All prerequisite classes including prerequisites of prerequisites to the lowest level visual part A part that has a visual representation at run time Visual parts such as windows push buttons and entry fields make up the user interface of an application Compare to view Contrast with nonvisual part visual programming tool A tool such as VisualAge that provides a means for specifying programs graphically Application programmers write applications by manipulating graphical representations of components 304 VisualAge for Smalltalk Handbook Fundamentals W WAN Wide Area Network Any internet or network that covers an area larger than a single building or campus See also Internet LAN network wide area network WAN A data communications network designed to serve an area of hundreds or thousands of miles for example public and private packet switching networks and national telephone networks widget An object that provides a user interface abstraction for example a scrollbar widget Widgets support obtaining input from the user and displaying output to the user window 1 A rectangular area of the screen with visible boundaries in which information is displayed Windows can overlap on the screen giving the appearance of one window being on top of another 2 In the VisualAge Comp
360. s its value from the script which can make calculations based on the values of other parts See also connection authority The right to do something on the system or to use an object such as a file or document in the system authorization list A list that gives a group of users one or more types of access to objects such as files or programs or data in the objects such as records in a file It consists of a list of two or more user IDs and their authorities for system resources backbone A high speed line or series of connections that forms a major pathway within a network The term is relative as a backbone in a small network is likely to be much smaller than many nonbackbone lines in a large network See also Network bandwidth The transmission capacity of the lines that carry the Internet s electronic traffic Historically it s imposed severe limitations on the ability of the Internet to deliver all that we are demanding it deliver but fiber optic cables will ensure that bandwidth soon will be essentially limitless and free Basic Input Output System BIOS In IBM personal computers with PC I O channel architecture microcode that controls basic hardware operations such as interactions with diskette drives fixed disk drives and the keyboard baud In common usage the baud rate of a modem is how many bits it can send or receive per second Technically baud is the number of times per second that the carrier
361. same message in different ways Different objects can have very different method implementations for the same message An object can send a message without concern for its underlying implementation pool dictionary A dictionary object whose keys define variables that can be shared by multiple classes All methods for a class can access the variables in a pool dictionary if the class declares the pool dictionary as part of its scope port 1 A place where information goes into or out of a computer or both For example the serial port on a personal computer is where a modem would be connected 2 On the Internet port often refers to a number that is part of a URL appearing after a colon right after the domain name Every service on an Internet server listens on a particular port number on that server Most services have standard port numbers Web servers normally listen on port 80 Services can also listen on nonstandard ports in which case the port number must be specified in a URL when accessing the server 3 Refers to translating a piece of software to bring it from one type of computer system to another See also domain name server URL POST One of the methods used in HTTP requests A POST request is used to send data to an HTTP server See also GET prerequisite application An application required by another application for it to function successfully An application can extend or reference one or more of the pre
362. ses Structuring a system into subsystems helps reduce complexity A common design goal is to minimize the communication and dependencies among subsystems The Facade class provides a single and simplified interface to the more general facilities of a subsystem Use Facade for suffix Controller Classes Controller classes handle the sequence of events found in a use case They deal with user interface logic or business processes Jacobson defines them as control objects Use Controller as suffix Agent Classes Agent classes are used to encapsulate the physical implementation of a portion of or whole service by using one or more service objects One agent class plays an intermediate role between one or more model classes which 2 3 Design Patterns Erich Gamma et al Addison Wesley Object Oriented Software Engineering Ivar Jacobson Addison Wesley Chapter 2 General Information 65 do not know anything about the outside world of a Smalltalk run time image and the service object which in turn does not know anything about the business domain Use the word Agent followed by the kind of service object used Here are some examples e AgentDB2 Classes implementing service using DB2 2 service objects AgentMQ Classes implementing service using MQSeries service objects e AgentTCPIP Classes implementing service using TCP IP service objects Manager Classes Manager classes keep track of all instances of a specific c
363. ses Vol2 196 local name server Vol2 222 TCP IP continued name server Vol2 201 Vol2 210 port number Vol2 221 socket Vol2 66 stack Vol2 51 Vol2 65 startup error Vol2 210 testing setup Vol2 65 using in scripts Vol2 66 Windows 16 bit Vol2 62 WinSock Vol2 65 Team Connection 6 team environment 243 257 identical users 256 terminating active processes 25 infinite loop 28 testing class 173 instance 173 text box default action 153 changing color 193 cursor position 131 database Vol2 132 transparent 135 thread 28 Vol2 114 Vol2 138 Vol2 143 Vol2 208 timestamp 247 Tivoli 21 toggle button 105 token ring Vol2 10 tool bar creating 109 sizing 259 TopLink Vol2 118 trace database connection Vol2 164 distributed Vol2 195 logging 54 method call stack 21 run time startup Vol2 205 tracking table cell changes 149 TrailBlazer class policy 57 code browser 192 compiler warning level 195 generating accessors 54 initializing class variables 209 TrailBlazer continued toBeLoadedCode 209 transaction abend Vol2 72 canceling database request Vol2 137 code page Vol2 73 database Vol2 14 distributed Vol2 217 interface Vol2 113 interleaving Vol2 39 multileaving Vol2 39 object Vol2 110 program Vol2 23 record Vol2 109 single Vol2 114 transcript logging messages Vol2 205 transfer queue Vol2 73 translation table 44 transparent text background 135 trapping errors 180 tree view 259 triggering events 44 trimm
364. signal shifts value for example a 1200 bit second modem actually runs at 300 baud but it moves 4 bits per baud See also bit modem behavior 1 The set of external characteristics that an object exhibits 2 The abstract class that provides common behavior for class and metaclass objects binary 1 Pertaining to a system of numbers to the base two the binary digits are 0 and 1 2 Pertaining to a selection choice or condition that has two possible different values or states bind The process by which the output from the SQL precompiler is converted to a usable structure called an access plan This process is the one during which access paths to the data are selected and some authorization checking is performed Glossary 281 bit binary digit A single digit number in base 2 in other words either a 1 or a zero The smallest unit of computerized data Bandwidth is usually measured in bits per second See also bandwidth bps byte kilobyte megabyte block A Smalltalk object consisting of one or more statements enclosed in brackets passed as arguments or used as the receiver of messages that implement control flow Blocks can define temporary variables for their own use Bps bits per second A measurement of how fast data is moved from one place to another A 28 8 modem can move 28 800 bits per second See also bandwidth bit browse A way of looking at a file that does not allow you to change it b
365. single line since the Enter key means add line to a multiline CwText Combo Box Behaviour Answer have dropped a combo box on my form populated it with a number of items and set one of them as the initial item grab the selected item and pass it to a variable When type a value in the combo box it seems to search the list of items for a match for example on the first letter typed Of course it does not display anything When tab out of the field and inspect the variable it has not captured the data entered in the field but instead it has the list item that matched on the first character Is this the default behavior of a combo box That is indeed the default behavior of a combo box The entry field is just for you to be able to type in an existing entry as an alternative to using the scroll bar to find it in the list However you can add the behavior you describe with a combination of connections and scripts Skipping through a Notebook 114 Answer l am writing an application demonstrating various features of VisualAge for Smalltalk One of the things want to do is to skip through a notebook without user intervention as in a slide show The question have is how can you automatically skip to the next page You can turn notebook pages by setting the currentPagelndex or currentPage Here is an example using delays so that the pages turn a bit slower VisualAge for Smalltalk Handbook Fundamental
366. sions on the Same System 26 Can keep both VisualAge for Smalltalk 2 0 and 3 0 on the same machine Yes they can coexist on the same machine You did not say whether you were on OS 2 or Windows However since Version 2 and 3 do not share DLLs of the same names keeping both is fairly easy Just put the period and semicolon in your path or libpath as the first thing so that files are picked up from your current subdirectory This may mean consolidating some of the files in the same directory Also watch the abtpath it can VisualAge for Smalltalk Handbook Fundamentals reference several subdirectories as well Libraries can be kept on the same machine just make sure you are pointing the clients to the right one Replacing the Default Icon Answer Escaping an How do replace the default VisualAge icon with my own If you do not want a splash screen everywhere abt exe is mentioned replace it with nodialog exe Abt exe can be found in your VISUALAGE subdirectory while nodialog exe can be found in your VISUALAGE DIALOG subdirectory Copy the abt rc abtrc h and the abt exe or nodialog exe files to your run time application directory from the dialog directory Do an edit of your abt rc and change the following line POINTER ID_ICONRESOURCE visAge ico to POINTER ID_ICONRESOURCE iconName ico e If you do not want a splash screen you can erase the rest of the abt rc file The rest of it pertains to the sp
367. sly does not solve your problem with dates and times If you feel you don t need all the error handling and locale support and you need performance suitable for loop processing you might consider writing your own simple parser class with tokenizing and conversion methods that are optimized for your application 220 VisualAge for Smalltalk Handbook Fundamentals Identity Test on String Answer have noticed an interesting fact on testing the identity of two string instances Smalltalk ab a myString b myString Given the above script thought that a b would result in false while executing a b gives you true as the result But found IBM Smalltalk returns true as the result of the identity test a b and am not quite sure why a and b are identical The reason for this behavior is due to compiler optimization Here s an example Suppose A and B are global variables Smalltalk A my string B my string A B If the code above is evaluated as a group you ll get true If you evaluate each line separately A B will return false When you create strings with the single quote you are creating a literal string Literal strings cannot be modified so as an optimization the variable a and variable b actually point to the same object This would usually create problems but since it s a literal you can t modify either one of them so it doesn t real
368. sort of naming restriction on Smalltalk to meet database limitations is not the right approach Reusing the Settings View Questioni Is it possible to reuse the VisualAge template for the settings view am creating custom parts and would like my settings to have the same look and feel as other VisualAge parts Are you asking if it s technically possible or legally possible believe the answer to be yes to either question For the technical side you can generate archival code and do a find or replace to change the class name to your settings view and then file that code in Chapter 4 IBM Smalltalk Programming Language 227 Exception doesNotUnderstand 228 Question need to know the IBM Smalltalk way of specifying an exception handler for doesNotUnderstand In Digitalk Smalltalk it used to look like this Smalltalk self foo on MessageNotUnderstood do self doesNotUnderstandHandler What is the IBM Smalltalk equivalent of this If you look at the method doesNotUnderstand in Object you see Smalltalk doesNotUnderstand aMessage Report to the user that the receiver class for superclasses do not implement any methods for the message selector contained within the argument aMessage self error self doesNotUnderstandError aMessage The upshot of this is there is no exception specifically for the doesNotUnderstand method You would have to catch it by catching all e
369. ss AbtNLSCoordinator classInstanceVariableNames currentCodePage instanceVariableNames classVariableNames CharacterSet CurrentLocaleMapping LocaleMappingCharacters poolDictionaries AbtConstants CfsConstants AbtPrimitiveNLSStrings AbtMsgBase r Chapter 4 IBM Smalltalk Programming Language 225 Class Naming 226 Answer Are there any performance considerations for the length Smalltalk class names and instance variable names In other words will a system with a bunch of 40 character names run slower than a system with a bunch of 4 character names In DB 2 shorter table names relate to faster response time because of more table entries in the hash table First you need to understand one of the very important concepts in Smalltalk the difference between instance identity and equality Two instance are if they are the same object which is to say they occupy the same memory location But may be different An expression a b answers true if the method for in the receivers class answers true That method may be redefined as appropriate for each class The default method for is the one in Object which is the same method as But for Strings you will find a different method that checks that the characters are the same Symbol is a subclass of String that maintains a SymbolTable as a class variable It is designed so that only one instance of Symbol has a given spell
370. ss Variables 0 2 0 2 0 20000000 209 Forking and Cycles 2 0 0 0 e 209 Converting Numbers Using printString 210 Garbage Collection of Instances 211 4 DIGItYiSars e ea ae ee Ais ie eR a ka ea eh Ee ee da 212 Fixing Date Years 22 452634 e be ee dra HEL RE ee ROS 212 ABT PAVE asar do od Gat CA a ct Bee de a BE 213 Double Triggering of Changed Events 213 Inheriting Visuals Associated with a View Class 215 Garbage Collector Problems 216 Integer Representation 0 0220020002048 216 Method Tracing vecina 4 eee a oe hg es 216 Storing Object of Unlimited Size 2 o 217 Collections and do 1 a 218 Fixed Object Spacen cen taa e a des ele Rieck Se Se he 219 Parsing Strings with Date Time 2 2 219 Identity Test on String 0 o 221 Replacing Character in String o 222 Padding Strings leticia aa dd to dao dd 223 Trimming a String o 223 Inhibiting List Selection 0 0 000000 00008 223 Resizable Table Rows 0 e 224 Adding wmUser Messages 0 00000 2p pees 224 New Operating System Event 2 225 Class Instance Variables 0 2 00 00 00000 ee 225 Class Naming 24 32 2884 ria php hoe hee 2 She a 226 Reusing the Settings View 2 000000 0020s 227 Exce
371. sses methods or both Hover Help Behavior 198 Questioni Why do see unpredictable behavior using hover help By default hover help displays the abe String attribute of a graphical label or push button All other parts including textual labels and push buttons do not display hover help Also if no label string is specified for a graphic label or push button no hover help will be displayed To specify the label string for a graphic push button open the settings for the part click on Text under Label type specify the label string click on Graphic again under Label type and click OK VisualAge for Smalltalk Handbook Fundamentals Aborting a Process Stack Question How can I abort the current process stack Either use exception blocks such as at ifAbsent or exceptions see the IBM Smalltalk Programmer s Reference l you are just looking to stop the exceptions from propagating down the stack you can add a signal exitWith nil to the end of your exception block If you instead want your entire application to stop then you can just System exit Exiting an Image Question In my application is there any means to exit the image programmatically Yes EmSystemConfiguration gt gt exit exits the image immediately so try this Smalltalk System exit Configured Subsystems Question How do see what subsystems am running You can programmatically see what variant of each basic subsystem you
372. stock image does Why did it seem that the reduced run time image had these applications It is likely that you reviewed the applications in the Packaged Image Browser associated with the reduced run time image specification If this is true you should note that these applications were not base applications and as such may not be completely added to the run time image Chapter 2 General Information 47 Packaging an Application for Windows Answer Is it possible to package an application that should run under Windows with VisualAge under OS 2 You cannot run the OS 2 packaged application under Windows regardless of whether that s native Windows or a Win OS 2 session In order to package your application for execution on a Windows platform you must have a copy of VisualAge for Windows from which to create the run time Icons and DLLs The VisualAge run time does not use ABTICONS DLL for any of its resources In fact the edittime doesn t either Only the SampleParts and VisualAge Examples Help use the resources contained in this DLL The DLL is provided simply to provide some common images for you to use in your application Now when shipping your packaged application you have to include the BMP files and not the ABTICONS DLL Packaging a Answer Workspace Is it possible to package an EtWorkspace with an application You cannot package an EtWorkspace because it is part of the edit time development environment
373. syCursor 100 makeWeak 170 showBusyCursorWhile 100 Vol2 18 maximumNumberRows Vol2 153 shutDownAll Vol2 33 methodAtFrame 196 signOff Vol2 34 millisecondsToRun Vol2 19 size limit Vol2 111 new 175 sorted 194 newRow Vol2 142 species 194 324 VisualAge for Smalltalk Handbook Fundamentals method continued startUp Vol2 33 syncExecinUl 193 to 189 toBeLoadedCode 209 254 Vol2 74 trace call stack 21 trimBlanks 223 unloaded 264 updateWidget 191 193 useDashedLines 36 value 172 visibility 175 wasRemovedCode 254 widgetUnderCursor 102 windowProc with with 225 method tracing 216 migration DB2 2 Vol2 125 minimizing window 94 minimum window size 96 missing archival code 68 carriage return 162 icons 50 method 53 modal dialog 94 model class 65 modifying system menu 41 Motif documentation 88 widget 87 XKCancel 135 mouse click with Ctrl key 159 cursor position 102 dragging 108 pointer changing 98 location 102 moving classes 29 icons 152 MPR files Vol2 251 MQ client Vol2 73 commitment control Vol2 78 connection problem Vol2 78 MQ continued EBCDIC conversion Vol2 75 logical unit of work Vol2 78 reading message Vol2 74 sample application Vol2 76 syncpoint processing Vol2 75 MQ client code Vol2 79 MQSeries AIX Vol2 73 MRI file 63 multiline edit part limiting lines 156 missing CR 162 parsing text 144 tab order 143 typed words 144 multiline edit window 144 multiline text 130 multimedia
374. t Determining Required ICs Tip The following script can be run to determine the ICs that are needed at run time It will show a list of all IC packaging instructions that are currently loaded When you select a packaging instruction the required run time ICs will be listed on the Transcript Chapter 2 General Information 75 Smalltalk icCollection instructionNames instructionName instructionClass work instructionNames EpAbstractPackagingInstructions withAllSubclasses collect ea ea name asString asSortedCollection asArray instructionName CwListPrompter new title Find IC files required by the selected IC items instructionNames prompt instructionName size 0 ifTrue self instructionClass Smalltalk classAt instructionName ifAbsent self icCollection Set new icCollection add instructionClass dumperOptions imageFileName instructionClass prerequisitelCs do eachIlCInstructionClass icCollection add eachICInstructionClass asClass dumperOptions imageFileName work Transcript bringToFront work cr nextPutAll The required ic files for instructionClass name cr cr icCollection isEmpty ifTrue work tab nextPutAll No IC files needed cr ifFalse icCollection asSortedCollection do each work tab nextPutAll each cr Required CAT and MPR Files for an IC Run time Image 76 Tip The following script
375. t A language syntactic unit consisting of an operator or other statement identifier followed by one or more operands stored procedure A procedure stored in a database system that contains SQL and other control statements structured query language SQL A language used to access relational databases subapplication An application contained by another application Using subapplications one can organize the classes of an application into a tree of subapplications or isolate the parts of an application that are platform specific subclass A class that inherits behaviors and specifications in other words methods and variables from another class Contrast with superclass subclass type In VisualAge or IBM Smalltalk an indication of how a subclass inherits instance variables from its superclass submit button A type of push button that can appear on a form A submit button initiates a connection to the HTTP server and sends a CGI Glossary 301 query using the data from the input fields as parameters subpart A part that is embedded within a composite part subsystem A secondary or subordinate system or programming support usually capable of operating independently of or asynchronously with a controlling system superclass A class from which another class inherits behaviors and specifications in other words methods and variables Contrast with subclass symbol In Smalltalk an object that represent
376. t 225 reinitializing common widgets 25 dependents 25 reinstalling AS 400 Connection feature Vol2 8 released version 246 releasing connections 95 locks 83 reloading application 249 remote command Vol2 43 Vol2 53 remote host connecting to Vol2 2 remote object dead pointer Vol2 204 packaging Vol2 204 without object ID Vol2 197 remote procedure call See RPC removed class 45 removing application 250 archival code 37 blanks in string 223 close option 97 damaged classes 40 elements from view 71 instances 35 registered event to script connection 30 renaming class 29 31 visual part 31 repeating record structures Vol2 37 replacing default icon 27 report adding fields dynamically Vol2 233 break protocol Vol2 236 calculated field Vol2 230 coElement Vol2 236 conditional printing Vol2 227 Vol2 233 counting unprinted value Vol2 232 default fonts Vol2 229 field breaks Vol2 230 hidden details Vol2 227 hierarchical break Vol2 235 HP printer Vol2 233 in ASCII file Vol2 232 iterator field break Vol2 226 omit printing Vol2 233 owner language Vol2 232 packaging application Vol2 230 printing performance Vol2 233 printing underlined words Vol2 232 saving printer settings Vol2 229 sums Vol2 227 underlined words Vol2 232 using multirow query Vol2 231 using scripts Vol2 231 Win32s error Vol2 226 reshaping hot spot 138 resizing container columns 123 resolution bitmap 131 centered window 93 display 92 independence 95 scree
377. t default readAndDispatch This is equivalent to going into a peek loop in PM that is Smalltalk while keep waiting condition if WinPeekMsg WinDispatchMsg This keeps the Ul responsive but don t recommend it except for implementing modality as btShellView gt gt suspendExecutionUntilRemoved does Execution Start Question How does my VisualAge application start execution In the Smalltalk image the default packaging specification prompts you for launch code This is text that is compiled into a method and called after the runtime image is started just before dropping into the polling loop In the VisualAge image the default packaging specification doesn t prompt you for any launch code it sends runtimeStartUp don t forget the capital U to all resident applications instead So you either need to supply launch code or a runtimeStartUp method If you are in a VisualAge image but your application is not a VisualAge application then you can specify EpStandardRuntimeSpecification which will prompt you for launch code and may end up with a smaller run time image Chapter 4 IBM Smalltalk Programming Language 203 Inheritance of Visual Parts Tip When inheriting visual parts you don t have the same flexibility as when inheriting scripts In the case where you override the inherited visual part or specialize it any subsequent changes to the superclass part are not visible
378. t files of any type as attachments enabled 1 On a LAN pertaining to an adapter or device that is active operational and able to receive frames from the network 2 Pertaining to a state of a processing unit that allows the occurrence of certain types of interruptions 3 Pertaining to the state in which a transmission control unit or an audio response unit can accept incoming calls on a line encapsulation The hiding of a software object s internal data representation The object provides an interface that queries and manipulates the data without exposing its underlying structure end user A person device program or computer system that utilizes a computer network for the purpose of data processing and information exchange enterprise A business or organization that consists of two or more sites separated by a public right of way or a geographical distance Ethernet A very common method of networking computers in a LAN Ethernet will handle about 10 000 000 bits second and can be used with almost any kind of computer See also bandwidth LAN event A representation of a change that occurs to a part The events on a part s public interface enable other interested parts to receive notification when something about the part changes For example a push button generates an event signaling that it has been clicked which might cause another part to display a window Compare to attribute event to action connectio
379. t in the settings for an entry field or programatically like this Smalltalk AbtDateConverter new showFourDigitYear true objectToDisplay Date today Or if you are running IBM Smalltalk you can also use Smalltalk IcTime Locale current IcTime copy IcTime dFmt m d Y IcTime printDate Date today on Transcript They are basically the same The problem with Date today printString is it always tries to go with the current locale If you want to override the locale you can add an entry to your NLS CNF file dFmt m d Y This will override the date format returned by the operating system See EsNlisImageStartUp gt gt abtActionTable for the other possibilities Fixing Date Years 212 Question When you enter two characters in the year area of a date field it defaults to 20 Is there a way to get date years to default to the current century rather than the 21st Gadda The rules for normalization of the year are as follows 1 100 lt y lt 9999 gt take as is 2 0O lt y lt 79 assume 21st century 2000 2079 3 80 lt y lt 99 assume 20st century 1980 1999 4 All others are invalid VisualAge for Smalltalk Handbook Fundamentals You may want to modify the instance method normalize Year in AbtDateParse class to customize the default ABTPATH Question Is there any way to find out the ABTPATH value set in config sys in VisualAge for Smalltal
380. t is filed in When making changes to the class it is easy to forget to run the method Most people put a comment at the top Smalltalk Don t forget to reinitialize me when you make changes ThisClassName initialize and then select the expression and evaluate it after making a change 168 VisualAge for Smalltalk Handbook Fundamentals Is there a way to take actions automatically each time when the class is recompiled Yes In the initialization method add this line Smalltalk System message self class name asString needs to be initialized This puts up a dialog at compile time to remind you to initialize the class The compiler being so helpful sometimes complains that this expression doesn t do anything So fake it out Smalltalk junk junk System message self class name asString needs to be initialized But you say why not initialize the class directly by putting this at the end of the initialize method Smalltalk ThisClassName initialize If you try it you discover that it indeed does run the method And you discover after a while that it doesn t contain the latest change but always the one before Make a change and it doesn t show up make another and the first shows up It s clear once you realize that Smalltalk ThisClassName initialize runs the method that is in the system The new method bein
381. t of copying going on An alternative and better solution when strings become large uses streams and works like this Smalltalk lumpSomeStrings arrayOfStrings aStream aStream WriteStream on String new arrayOfStrings do aString stream nextPutAll aString stream contents Basically a stream continues to add on new stuff behind previous stuff in a large working collection called the stream contents If the working collection fills up the stream allocates a bigger collection and copies the data to it It is possible to prevent all copying by specifying the size of the collection VisualAge for Smalltalk Handbook Fundamentals Smalltalk lumpSomeStrings arrayOfStrings aStream length E changed length arrayOfStrings E new inject O E new into len str len str len E new aStream WriteStream on String new length changed arrayOfStrings do aString stream nextPutAll aString stream contents The inject into method is not often used but it should be Here it is used to sum the lengths of all of the strings in arrayOfStrings and in one simple expression All of these examples answer the same string at least accoring to Comparing Floating Point Values Tip This expression answers false but it looks like it should answer true Smalltalk 45 0 1 15 10 0 45 0 10 0 1 15 So is it
382. t should not be hard to add something to the settings page of the container to encapsulate this behavior VisualAge for Smalltalk Handbook Fundamentals Disabling a Notebook Tab Answer How do disable the tab of a notebook There are several kinds of notebook types but one of them offers an aboutToChangePage type event that you can hook up to do the very thing you want to do List with Icon Column Questioni How do create a list with an icon column and several detail columns You need to use a details tree container part First the column parts should have an attribute to display value specified in their settings view Second the objects that you are using as the items should have methods with the names you specified in the attribute to display fields of the column part s settings For the column where you want the icon its Attribute to display method should answer return an instance of Cglcon Since the details tree container has multiple columns you can specify an icon for any of the columns not just one column and not just the first column This is why the icon attribute of the visual information requested is not used This also works with bitmap resources if you return them as pixmaps Hiding a Column Questioni How do I hide a container details column using the hide action Hiding a container details column is not supported even though the actions to hide and show the column are in its public int
383. tToOpenProcessing You are now ready to test your part just connect the items attribute of the container icon list to the data items you want to display 120 VisualAge for Smalltalk Handbook Fundamentals Smalltalk aboutToOpenProcessing iconListwidget Get the container icon list wigdet at the Ew layer iconListwidget Container Icon List1 widget Set up our own background drawing callback iconListwidget applicationDrawnBackground true iconListwidget addCallback XmNdrawBackgroundCallback receiver self selector drawBackground clientData nil drawBackground aWidget clientData clientData callData callData oldColor anRC Only draw the label background in this case callData region XmLABELREGION ifTrue anRC oldColor anRC setForeground aWidget colorMap palette nearestPixelValue CgRGBColor red 16rFFFF green 16rFFFF blue 0 anRC drawable fillRectangle anRC gc x anRC x y anRC y width anRC width height anRC height anRC setForeground oldColor Deselecting Details Tree Items Question have set up a container details tree to display two levels of information A second list box displays the selected entries from the first When a parent is expanded and its child is selected all works fine However if collapse the parent without deselecting the child the child is automatically deselected anyway This does not seem to be the proper behavior upon colla
384. talk Tools Manage Applications e From the list of applications select the application version you want to export e From the Application menu option select System gt Export To e In the displayed prompter specify the path and file name for the target library e Click on OK The system moves a copy of the application version from the library you are currently using to the target library If you cannot fit this file on one diskette try using saveram or some other tool that can split and pack files From the image on the VisualAge for Smalltalk workstation where you wish to import the application VisualAge for Smalltalk Handbook Fundamentals Open the Application Manager Browser e From the Application menu option select Select Import gt Applications e In the displayed prompter specify a path and file name for the library storing the component e Click on OK A window is displayed prompting you for the name and version of the application you want to import e Select an application then select a version of the application e Click on OK A copy of the application version is moved from the selected library into the library you are currently using Associating DAT files with Features Answer How can figure out which feature was installed or loaded from which DAT file Does there exist a cross reference list so can identify the DAT file with a given feature To figure out which DAT is w
385. tation that interfaces with all of the architectural layers of that station and is responsible for the resetting and setting of control parameters obtaining reports of error conditions and determining whether the station should be connected to or disconnected from the network nil The object in Smalltalk that means no value All variables initially refer to nil It is the single instance of the UndefinedObject class node 1 Any device attached to a network that transmits and or receives data 2 An endpoint of a link or a junction common to two or more links in a network 3 In a network a point where one or more functional units interconnect transmission lines node name In VTAM the symbolic name assigned to a specific major or minor node during network definition nonvisual class A class in a VisualAge application that specifies a nonvisual part For example Person Address and BankAccount are nonvisual classes nonvisual part A part that has no visual representation at run time A nonvisual part typically represents some real world object that exists in the business environment Contrast with view visual part notebook In VisualAge a view that resembles a bound notebook containing pages separated into sections by tabbed divider pages A user can turn the pages of a notebook or select the tabs to move from one section to another O object 1 The basic building block in Smalltalk development An obj
386. tems such as adding multiplying comparing or moving option 1 A specification in a statement a selection from a menu or a setting of a switch that may be used to influence the execution of a program 2 A hardware or software function that may be selected or enabled as part of a configuration process 3 A piece of hardware such as a network adapter that can be installed in a device to modify or enhance device function P panel 1 A formatted display of information that appears on a terminal screen Contrast with screen 2 In computer graphics a display image that defines the locations and characteristics of display fields on a display surface parameter 1 A data element included as part of a message to provide information that the object might need In Smalltalk generally referred to as an argument 2 A variable that is given a constant value for a specified application and that may denote the application 3 An item in a menu or for which the user specifies a value or for which the system provides a value when the menu is interpreted 4 Data passed between programs or procedures part A self contained software object with a standardized public interface consisting of a set of external features that allow the part to interact with other parts The parts on the VisualAge parts palette can be used as templates to create instances of objects 296 VisualAge for Smalltalk Handbook Fundamentals par
387. tentially be finalized in the next cycle The finalization cycle is run when the system is idle Continue Background Process Questioni Is there any way for a process to continue execution after suspendExecutionUntilRemoved has been issued The example below shows that execution of background processing continues during suspendExecutionUntilRemoved Smalltalk shell widget shell AbtShellView newPart openWidget widget shell widget notNil and widget isDestroyed not whileTrue CgDisplay default bell 100 Delay forSeconds 3 wait forkAt Processor userSchedulingPriority shell suspendExecutionUntilRemoved Chapter 4 IBM Smalltalk Programming Language 201 Automatic Log Off Answer How do implement a timeout feature that automatically logs off a user after a minute of inactivity This is tricky stuff Our Multimedia parts do something like this for the same purpose The approach is to replace the handlers in the EventTable for all mouse and keyboard events and reset a timer each time one of these is hit See OsWidget gt gt mtrTrackAllInputActivity in the subapplication AbtMultimediaAuthoringPM Win You have to be careful that the code you invoke in the new handlers is safe for all widgets and reset the handlers when you are done can also think of another way although have not tried it suspect if you modified the implementors of callCallbackList callData to log the time
388. terating over Widgets 0 0 0200 VisualAge for Smalltalk Handbook Fundamentals Modal Dialog ers ca oo sta Bed ee be a is Bala A eae ee AD ed Beg 94 Capturing the Minimize Request aaa aaa 94 Window Synchronization 2 0000 pee 95 Closing a Window 0 00 2 95 Resolution Independent Screen 2 0 2 95 Setting Minimum Window Size 02 2 020058 96 Closing a Widget from a Script aoaaa a 96 Removing the Close Menu Option 2 4 97 Widget Warning Circular Reference 97 Always on Top Window oaaae 98 Changing the Mouse Pointer 2 o 98 BUSY GUISO ia o ta tan GLa ee eed 100 Caret Shape Cursor 102 Mouse Pointer Location 0 0200020 eee 102 ICON AS GUISO ir EA Bh a ee a eS 103 Animated Busy Cursor aoaaa aaa 105 Adding Pull Down Menu Choices Dynamically 105 Toggle Buttons in Menus 2 ee 105 Disabling Push Buttons on Pop Up Menus 106 Pop up Menus for Icon Gadgets 107 Sharing a Menu Between Containers 108 Dragging Versus Pop Up 2 o 108 Icons on a Menu Bar 0 00 2 108 Creating a Tool Bar 00000 a 109 Synchronizing a Combo Box o 109 Adding Items to Combo Box 0 2 0000 eee 110 Drag and Drop Support on List Boxes 110 List Box Behavio
389. that are logically arranged by the values of a key Indexes provide quick access and can enforce uniqueness on the rows in a table inheritance A relationship among classes in which one class shares the structure and behavior of another A subclass inherits from a superclass initialize In a LAN to prepare the adapter and adapter support code if used for use by an application program input output I O 1 Pertaining to a device whose parts can perform an input process and 290 VisualAge for Smalltalk Handbook Fundamentals an output process at the same time 2 Pertaining to a functional unit or channel involved in an input process output process or both concurrently or not and to the data involved in such a process inspector A Smalltalk tool for viewing the data of any Smalltalk object instance An object that is a single occurrence of a particular class An instance exists in memory or external media in persistent form Compare to persistent object instance method In Smalltalk a method that provides behavior for particular instances of a class Messages that invoke instance methods are sent to particular instances rather than to the class as a whole Contrast with class method instance variable Private data that belongs to an instance of a class and is hidden from direct access by all other objects Instance variables can be accessed only by the instance methods of the defining class and its subc
390. the appropriate logic within your own application which supports this type of behavior that is uses ApplicationLoader to bind APP files under certain conditions If you add the logic yourself it is your responsibility to ensure that the reduced run time image contains all the necessary methods to support the methods required by your application modules APP files Missing Icons Answer Why do have missing icons after packaging the application VisualAge caches the window handles of the icons used in the message prompter The cache is cleared when the image is saved If you package your application before saving your image the current window handles of the icons get packaged into the run time image When you run the packaged image these window handles are no longer valid and as a result you get missing icons or a trap A quick fix to the problem is to save your image and then package your application don t test it after saving the image A more appropriate solution is to implement a private class method in AbtPromptersAppWithUI called packagingRulesFor which will clear the cache prior to packaging Underneath you find the code for this method Smalltalk packagingRulesFor aPackagedlmage Define rules for the given packaged image aPackagedImage initializeToNilClassVariable AbtIconPixmaps inClass AbtExtendedMessagePrompter Required CAT Files 50 Answer How do find out what CAT files are
391. the creation of libraries These libraries are useful for moving applications from one installation to another They can also be used for making backups or for providing a reusable library to share between development installations VisualAge for Smalltalk Handbook Fundamentals Import and Export Questioni How do import and export applications from a library file In the VisualAge for Smalltalk Organizer open the menu titled Applications Select submenu Import Export Select menu item Import Applications In the resulting file dialog locate the library file with dat extension and click OK The contents of the library file will be presented Select the application and version that you want to import and click the gt gt button this includes the selected application and version in the list of things to import Click OK The version s of the application s you selected will be imported into your current library but they will not be loaded into your image Loading Applications Questioni How do load applications from the library In the VisualAge for Smalltalk organizer open the menu titled Applications Select submenu Load Select menu item Available Applications A list of applications that have not been loaded in the image will be presented Select the application and version that you want to load and click the gt gt button this includes the selected application and version in the list of things to load
392. the same logical sequence A session is identified by a unique session key which is generated by VisualAge A session begins when a client initially connects without a session key and ends when a specified timeout period has elapsed since the last connection session key A unique string generated automatically by VisualAge that identifies a session All requests and replies carry the session key in hidden HTML data fields session layer The layer that provides the services that organize and synchronize communications between functional units in different open systems located in the presentation layer settings view A view of a part that provides a way to display and set the attributes and options associated with the part simple dialog A dialog that takes one data record from the initiating object and sends it to a remote program which returns the result to the initiating object Compare to multireceive dialog Smalltalk ST 1 A complete programming environment for developing object oriented applications Smalltalk is a pure implementation of object oriented concepts every entity in the environment is an object 2 The name of the programming language that the Smalltalk programming environment supports 3 In the IBM Smalltalk programming environment the name of the System Dictionary containing the global variables SNA See Systems Network Architecture socket 1 In the TCP IP environment a socket is an
393. the system as a specific type of object The system recognized identifier for the object type is DTAQ data structure The syntactic structure of symbolic expressions and their storage allocation characteristics data transfer 1 The result of the transmission of data signals from any data source to a data receiver 2 The movement or copying of data from one location and the storage of the data at another location deactivate To take a resource of a node out of service rendering it inoperable or to place it in a state in which it cannot perform the functions for which it was designed Contrast with activate deallocate A logical unit LU 6 2 application program interface API verb that terminates a conversation thereby freeing the session for a future conversation Contrast with allocate debugger A software tool used to detect trace and eliminate errors in computer programs or other software default Pertaining to an attribute value or option that is assumed when none is explicitly specified delimiter 1 A character used to indicate the beginning or end of a character string 2 A bit pattern that defines the beginning or end of a frame or token on a LAN dependent LU Any logical unit LU that receives an ACTLU over a link Such LUs can act only as secondary logical units SLUs and can have only one LU LU session at a time Contrast with independent LU Glossary 285 destination Any point or l
394. then add individual buttons to it Each button can then be enabled or disabled An example of how to do this is listed below 106 VisualAge for Smalltalk Handbook Fundamentals Smalltalk createPopup parent menu menu parent createPopupMenu popup argBlock nil menu createPushButton Add argBlock nil addCallback XmNactivateCallback receiver self selector addSomething clientData callData clientData nil setSensitive false manageChild menu Pop up Menus for Icon Gadgets Answer How do dynamically create pop up menus for dynamically created icon gadgets To dynamically create a pop up menu for the dynamically created icon gadget use the following Smalltalk Create an icon gadget for each item and set its attributes iconGadget AbtlconGadgetView new label Mylcon largelcon icon parentView container openWidget yourself Instead of making the association with the menu before the open Widget message add the following code afterward to associate the pop up menu with the icon Chapter 3 Graphical User Interface 107 Smalltalk iconGadget menu self subpartNamed Menu1 parentView container openWidget Sharing a Menu Between Containers If you want to share a menu you will need to create a reusable menu part and add multiple instances of it for connecting to each container See page 413 of the VisualAge for Smalltalk User s
395. this kind of error occurs The block takes a single parameter an instance of class Signal In this case an error when trying to read a file is considered final The message exitWith sent to the Signal will exit the block with the provided value nil in this case The variable contents should either be a string or nil The file is closed and if successful the contents is answered Otherwise the result of evaluating errorBlock is answered Catching All Answer Errors How do catch all errors Use ExError for the kind of error to catch Smalltalk succeeded succeeded lt do something gt true when ExError do signal signal exitWith false In this example the variable succeeded is set to true if the lt do something gt works without signaling any errors the variable is set to false otherwise You should not generally try to catch all errors because you will also catch programming errors including messages not understood Flaws in your code may go unnoticed with unexpected results Chapter 4 IBM Smalltalk Programming Language 181 Exception Handling Code Question When should include exception handling code In general exception handling should be added after you are convinced your code works Exception handling should be used to catch unexpected problems for example your file server shutting down Fixed Decimal Class Question Is there a fixed decimal class availab
396. thod window choose Move Methods To a new Class from the Methods pull down menu Type in the new class name when prompted Be sure to move all class and instance methods both public and private over to the new class Test your new class to make sure it behaves as the other one did When you are positive that your new class works you may delete the old one if it is not needed anymore Environment Variable Questioni How do get the value of an environment variable defined in config sys There is a private method called abtScanEnv in EsString that should do what you desire To use it try executing the following code Smalltalk PATH abtScanEnv Chapter 2 General Information 29 Registered Connection Questioni How do remove a registered event to script connection Try sending destroyPart to the connection you dynamically created Loading Different Image Questioni How do specify a different image from a command line MS You can use the i parameter for example abt exe id va30 image Deferred Update Part 30 Questioni How do use the Deferred Update Part Opinion One Deferred update parts exist only to buffer editing of control widget values Although there is sufficient demand for things like buffering the practical use of the deferred update part is rather limited The limitations are twofold First the part assumes that your objects are just objects that contain data
397. tic especially since all connections are placed in a single method Now with the archival code you can make the decisions You can override the appropriate methods and keep Button1 in View2 or you can modify the method that creates Button2 and change it so that it does not attach itself to Buttoni But be warned once you start down this path using the Composition Editor to maintain your views is probably not feasible Again can t over emphasize the risks you are taking by doing this Does this sound like the voice of experience Yes unfortunately it is If you are not fond of or comfortable with scripting today then this is absolutely not for you Chapter 4 IBM Smalltalk Programming Language 215 Garbage Collector Problems Answer lam having a problem that instances are not removed by the garbage collection process If open a class MyView 30 times then MyView has 30 instances even after forced garbage collection don t expect other objects to reference instances of MyView Could there be any other reason that instances of MyView are not garbage collected A suggestion would be to start doing this 1 Save your image so you can come back to it if necessary 2 Execute System abtScrubImage 3 Check for instances a If they are still there you start to suspect class variables or globals in the Smalltalk dictionary b If they are gone then start the image again so you can get those instances back and exec
398. tion there where for each line feed the height is increased by the size of the font Adding wmUser Messages 224 How do add a wmUser message The C DLL that I m interfacing to sends wmX messages to my Smalltalk image for processing I ve figured out how to add missing Presentation Manager wmX messages via the OSWidget method eventTableAt put with but not wmUser messages VisualAge for Smalltalk Handbook Fundamentals could subclass OSWidget add my new event and then reimplement windowProc with with to check for my event and process it Is this the correct or preferred way When you say reimplement windowProc with with you mean in your subclass right This is certainly the most efficient way of doing this The other option would be to add an entry in the event table and extend OSWidget to add the new event However the event table is currently a 1023 element array and arrays can t be grown so in order to get WM_USER 4096 in there you d need to replace the current array with an all new one New Operating System Event Questioni How do register a new operating system event To register a new event use OSWidget method eventTableAt anInteger put anObject where aninteger is the event number and anObject is a symbol that is your selector name Class Instance Variables Question Are there class instance variables in IBM Smalltalk Yes they are there Here is a sample Smalltalk Object subcla
399. tly in size yet have added little to it At the same time performance seems to degrade Why is this happening and can fix this Close all VisualAge windows except the Transcript Type Smalltalk Dependents in your Transcript select and inspect it If more than self and Behavior is in the leftmost window pane type Smalltalk Object abeReinitializeDependents in your Transcript select and execute it Then save your image The size of your image should reduce back to what it was initially Object abeReinitializeDependents frees up the resources associated with any existing dependents When you use a part that is not subclassed from AbtObservableObject and you establish connections to this part so that other parts are notified when this part changes you create dependents Here s something else to check From the Transcript select Smalltalk Tools gt Open Debugger Then from the debugger select Processes gt Debug Other Typically there are two If there are many more select and terminate them If you try these things and your image is still quite large try this from the Transcript Save parts and close all windows first Smalltalk EmSystemConfiguration new abtScrublmage VisualAge for Smalltalk Handbook Fundamentals This reinitializes dependents removes and terminates active processes and reinitializes common widgets It closes all VisualAge windows and returns the Syst
400. to VisualAge for Smalltalk Handbook Fundamentals traversal only Consequently you see numbers like 1 1 1 2 1 3 It s acting as though it s within a tab group and will always be added as 1 x Since you can change the tab order of parts at the same level only you have two options Do not put the push buttons directly onto the window put them in a form as with the other push buttons Or check the tab group option on the individual push buttons You will have to use the tab key to navigate to and from these push buttons if you choose the latter option Ctrl Click Events Answer can set individual button press ButtonPressMask and key press KeyPressMask event handlers But how can detect if a key was pressed at the same time a mouse button was pressed am trying to differentiate between a mouse button Ctrl key event and just a mouse button pressed event You will have to process the keyboard key and mouse button events individually A suggestion is to set a flag when the mouse button has been pressed but not released When you process the keyboard key event check to see if the mouse button flag has been set If it has and the Ctrl key was pressed execute your mouse button Ctrl code You will need to clear the mouse button flag whenever the mouse button is released Here s another probably easier way of doing the same The method that processes the keyboard key event can check the event state If the state
401. to the class during the creation of the deferred update part instance These methods respond with a class name which the Manager uses to instantiate the deferred part and there you could implement some of the behavior such as changing attribute b when a attribute changes The object you will be dealing with at that time is the update operation whose target is your object which is undergoing a change Hence you can ask your object to recalculate some other value based on the attribute changed My recommendation would be to attempt to use deferred update parts and enhance them when needed The benefit is that there is so much infrastructure there The Command or the Momento pattern is nice but not as easy to implement from scratch Also if one uses VisualAge correctly that is having a form work with a single object that includes nested forms which in turn edit other complex attributes of your object deferred update parts work great As for seeing noncommited object changes when a different editor is opened on the object currently being edited say it is up to your personal preference One must have a pretty smart application based transaction framework to support such behavior What about different views editing the same object Getting the transient state of an object is wonderful as long as you are willing to pay the price for the added complexity Renaming a Visual Part Answer How do rename a visual part The current im
402. to the subclass as saving the changes causes the regeneration of the abtBuildInternals and other run time methods which are completely overridden by the same run time methods in the subclass Here are scenarios for visual parts e Class B is inherited from class A Class B remains unchanged Class A is changed The changes to class A will show up in class B e Class B is inherited from class A Class B is changed or specialized Class A is then changed The changes to class A will now not show up in class B As a result inheriting visual parts should be thought of as a one time copy Therefore you should be careful to stabilize the visual part class you are inheriting from as much as possible before inheriting Multithreading 204 Questioni Does VisualAge support OS 2 multithreading You can create multithreaded like applications through the use of Smalltalk processes Although the processes actually run under a single thread calls to external functions can run on a thread separate from the base Smalltalk Although the ability to access all OS 2 APIs does exist some functions such as semaphores are implemented inside Smalltalk to support its scheduling of processes When you call external code from VisualAge all of its processing and the external function s processing are executed on a single thread This means that while the function is being run processing for the rest of VisualAge is halted including processing for the no
403. truction from parts A software development technology in which applications are assembled from reusable and existing software components known as parts control language The set of all commands with which users request functions from the system controller A unit that controls input output operations for one or more devices conversation In SNA a logical connection between two transaction programs using an LU 6 2 session Conversations are delimited by brackets to gain exclusive use of a session CORBA See Common Object Request Broker Architecture CPI C See Common Programming Interface Communications CUA See Common User Access Customer Information Control System CICS An IBM licensed program that enables transactions entered at remote terminals to be processed by user written applications It includes facilities for building using and maintaining databases Cyberspace Term originated by author William Gibson in his novel Neuromancer the word Cyberspace is currently used to describe the whole range of information resources available through computer networks D data area A system object used to communicate data such as common language variable values between the programs within a job and between jobs A data area is identified to the system as a specific object type The system recognized identifier for the object type is DTAARA database file A system object of the type FILE that contains descript
404. true progress not simply a bouncing ball graphic that indicates passage of time Trying to provide a smooth visual with background processes running is difficult because of two factors user interface processes try to run when Chapter 4 IBM Smalltalk Programming Language 209 everything is idle and when they finally do they run to completion under the assumption that won t be long You can try and override this behavior using yield and CwAppContext default syncExecInUl lt gt but often the results are not smooth and predictable Converting Numbers Using printString 210 Question In an older version of VisualAge could perform the following Answer Smalltalk 1 02 asDecimal printString This would produce a string of 1 02 If try to do the same in Version 3 0 it would produce the following string 1 02d16 15 How can make Version 3 produce a result similar to that of Version 2 The printString method is really for debug purposes since it is not sensitive to national language support NLS considerations period vs comma negative indicator and so on Instead use the locale classes IBM Smalltalk or AbtConverter classes VisualAge For example Smalltalk AbtDecimalConverter new objectToPrint 1 02 asDecimal or Smalltalk stream stream WriteStream on String new 128 Locale default IcNumeric printNumber 1 02 asDecimal on stream stream contents Bot
405. ts Note that the integer tests actually run with approximately 640 keys because of the way random keys are generated whereas the float and string tests have 1000 keys Cases with 100 integers run with a result of about 100 and are thus not twice as good as strings as might be assumed from the raw data in the table Symbols also make great dictionary keys because each has an associated unique integer hash However it is not good practice to create a large number of new symbols use symbols only for method names The following test routine is almost the same for all tests It generates up to 1000 keys and inserts them into either a dictionary or a table It also builds a set that contains the keys The timing test consists of accessing each key twice once to fetch the value and once to set the value Chapter 4 IBM Smalltalk Programming Language 235 Smalltalk randy coll set n slot key n 1000 coll Dictionary new E THIS LINE CAN CHANGE randy EsRandom new set Set new n timesRepeat key randy next slot key printString E THIS LINE CAN CHANGE coll at slot put randy next set add slot 2 Time millisecondsToRun set do e coll at e put coll at e 136 137 E This line shows one or more timing results In the following the example above would be shown as Smalltalk coll slot Dictionary new key printString 136 137 Co
406. ts palette In the VisualAge Composition Editor an organized collection of visual and nonvisual parts used in building composite parts for an application The parts palette is organized into categories Application developers can add parts to the palette for use in defining applications or other parts password In computer security a string of characters known to the computer system and a user who must specify it to gain full or limited access to a system and to the data stored within it path 1 In a network any route between any two nodes 2 The route traversed by the information exchanged between two attaching devices in a network 3 A command in IBM Personal Computer Disk Operating System PC DOS and IBM Operating System 2 OS 2 that specifies directories to be searched for commands or batch files that are not found by a search of the current directory PATH_INFO A CGI variable usually transmitted to the CGI program in the form of an environment variable The PATH_INFO variable contains all path information from the URL following the name of the CGI executable For a Web Connection application this information is the same as the VisualAge part name persistent object Instances stored outside of the image A persistent object must be loaded into virtual or real storage before it can process messages sent to it personal computer PC A desk top free standing or portable microcomputer that usually consists of a
407. ty Vol2 18 Vol2 27 conversion tables Vol2 13 Index 313 210 138 converting numbers coordinates of hot spot copy book Vol2 101 copyright 200 CORBA 2 64 Vol2 195 Vol2 239 CPI C Vol2 114 creating class from script 229 object at compile time 167 Crystal Wave 85 CTL file 80 Ctrl click events 159 CUA compliance 10 88 cursor animated 105 busy 100 Vol2 17 caret 102 change pointer 98 control Vol2 179 deleting rows Vol2 163 file position Vol2 4 icon 103 position in text 131 position on 3270 terminal Vol2 79 positioning window at 90 reusing Vol2 133 scrollable Vol2 167 Stability Vol2 58 customizing connection menu 33 CwConstants 41 D damaged class data integrity Vol2 15 structures Vol2 37 translation Vol2 73 data converter error message data definition specification See DDS data entry part data queue filling record Vol2 6 passing data Vol2 36 PTF Vol2 31 sharing Vol2 43 40 251 135 141 314 VisualAge for Smalltalk Handbook Fundamentals data queue continued synchronizing applications Vol2 8 variable length Vol2 34 data types Vol2 130 database access set Vol2 127 Vol2 152 Vol2 157 Vol2 169 Vol2 185 Vol2 192 active connection Vol2 193 ANSI SQL Vol2 140 API methods Vol2 163 automatic connect Vol2 148 automatic log on Vol2 131 bind Vol2 147 binding Vol2 140 Vol2 173 blocking factor Vol2 15 CAE 2 Vol2 145 call level interface Vol2 120 canceling request Vol2 137 changing
408. u need to substitute strings at set positions within a source string The bindWith family of messages answers with the string formatted under the control of the receiver The receiver is a character string patterned after the formatting conventions of printf and contains field descriptors used to insert arguments into the format string If you use the bindWith family of messages and you have VisualAge for Smalltalk then you can send each argument the message convertToDisplay and the conversion will be performed along with the substitution If you just have IBM Smalltalk you may want to extend the Object class to have an asString method that returns self printString and you would then be able to use asString polymorphically with your arguments Testing Instances and Classes Question It seems strange that have to create special classes to test my classes and methods Doesn t it seem that Smalltalk should have a test method besides instance and class methods The idea is that a builder like VisualAge would strip out test methods when the class is packaged With test methods for both class and instances l d be able to keep the tests with the class Chapter 4 IBM Smalltalk Programming Language 173 Answer Why don t you code Example comments in each method which are the test cases I reckon about 30 of my code is such test cases You can highlight the example code and execute it to verify the test but as it s a
409. uage Smalltalk is an important and emerging object oriented language in the industry Its use in business and commercial application development is growing rapidly IBM is chairing the effort to develop ANSI standards for Smalltalk and a full range of third party consultants tool vendors and service providers are available to complement the offerings of Smalltalk vendors IBM recognizes the value of Smalltalk and is delivering a full range of tools education consulting and service offerings to address this important market Smalltalk and Java Question Will Java overpower Smalltalk While not disregarding the strength of Java we must note that Smalltalk is superior to Java in many ways The main strength of Smalltalk is its maturity Smalltalk has been around for 25 years By contrast Java is in its very infancy Smalltalk s maturity has some important effects e Code quality Smalltalk systems have been refined by several generations of programmers and have proved to be free of both coding bugs and more importantly ideological bugs e Legacy code There is a huge estate of existing Smalltalk applications e Performance Smalltalk is quite fast thanks to the concerted efforts of many programmers during the last 25 years Java needs an investment of similar effort to reach a comparable level of performance Configuration Management Questioni How does VisualAge for Smalltalk support configuration management OTI s E
410. ualAge for Smalltalk Handbook Fundamentals Smalltalk showWallpaper anlmageDescriptor anlmageDescriptor AbtIimageDescriptor new moduleName lt d myPath imageFileName gt yourself self subpartNamed Window primaryWidget shell window setPalette anlmageDescriptor image palette self subpartNamed Window backgroundGraphicsDescriptor anlmageDescriptor In the self subpartNamed Window above Window should be replaced with the name of the part where you want to specify the wallpaper Questioni Is it true that the wallpaper of a window part under Windows 3 1 can represent only 16 colors Under Windows by default the color palette of the image is mapped to the closest values of the system palette Typically the system palette does not have many of the colors found in most bitmaps so the mapping is poor To get the image to appear the way you want add the following code snippet just before you display your image Smalltalk lt myWindow gt primaryWidget shell window setPalette lt mylmageDescriptor gt image palette This code snippet must be executed after lt myWindow gt has been opened Labels on Message Prompter Questioni Can I change the labels on an AbtMessagePrompter No AbtMessagePrompter uses CwMessagePrompter which uses the native operating system API such as WinMessageBox under OS 2 and that does not support button string substitution suggest
411. ue methods add cls class compiledMethodAt sel MethodBrowser new label References to str literal str openOn methods Free Disk Space Question Does anybody know how to retrieve free disk space information on Windows platforms Answer The GetDiskFreeSpace function call returns the following information 1 Number of sectors per cluster 2 Number of bytes per sector 3 4 Total number of clsuters on the disk Number of free clusters on the disk Pointers to variables where the above information can be returned must must be passed to the GetDiskFreeSpace function To get the total amount of free disk space you must multiply the sectors per cluster by the bytes per sector by the number of free clusters Listed below is code that will call the GetDiskFreeSpace function calculate the amount of free space on C and display that value in a message prompter Chapter 4 IBM Smalltalk Programming Language 233 Smalltalk oscall freeSpace sectorsPerCluster bytesPerSector freeClusters totalClusters rc oscall OSCall new sectorsPerCluster ByteArray new 4 bytesPerSector ByteArray new 4 freeClusters ByteArray new 4 totalClusters ByteArray new 4 rc oscall getDiskFreeSpace C IpSectorsPerCluster sectorsPerCluster IpBytesPerSector bytesPerSector IpFreeClusters freeClusters IpClusters totalClusters freeSpace sectorsPerCluster abtAsInteger bytesPerSe
412. ued openWidget which in many cases is not desirable got around this by the following code Smalltalk self subpartNamed MyWindow value isNil ifTrue self subpartNamed MyWindow createValue However both value and createValue selectors are private How can solve this problem without resorting to the use of private methods You should be able to set feature values via attribute to attribute connections Although the connections will not actually do anything until the view is created once it is all the connections are aligned Adding Columns to Tables Answer How can dynamically add columns to a table Here is some code that will give you the ability to add columns dynamically 146 VisualAge for Smalltalk Handbook Fundamentals Smalltalk AbtTableView gt gt addLastColumnNamed aColName columnHeader aColumnHeader attributeName anAttributeName readOnly aBoolReadOnly converter aConverter Public This is a helper function which will create a new column view and add it to the table The column will be added to the end of the table Its width will be equal to the width of the most narrow column currently in the table cv cv AbtTableColumnView new attributeName anAttributeName columnHeader aColumnHeader readOnly aBoolReadOnly ratioWidth self suggestedNewColumnWidth converter aConverter self subpartNamed aColName put cv cv openWidget true
413. ular primitive objects Changing a Table Cell Answer How do keep track of changes made to a cell in a table It may be best to track this at the model level not the view That is register interest in your model for the events that are important to you For example se f for an ordered collection dropped on the free form surface will gives you notification everytime the collection changes Presumably your model is more interesting than an ordered collection person employee company whatever so you should register interest in whatever event is important to you based on the public interface you defined Chapter 3 Graphical User Interface 149 Selecting Multiple Rows Answer How do select multiple rows in a table part You can do this using the Container Details View You just go into the settings and specify Multiple as the selection type Changing Push Button Activation 150 Answer How can change push button enablement when text is entered in a textbox There are several ways to go about doing this depending on what you d like to happen Here are two examples The first example starts off with a text box and a push button that s initialized as disabled You can disable a push button initially by going into the settings for the push button and removing the check mark next to the enabled box Disable the push button before making the following connection Connect the object event of the text box to the
414. unction with a terminal emulator host 1 A computer that hosts outside computer users by providing files services or sharing its resources 2 Any computer on a network that is a repository for services available to other computers on the network It is quite common to have one host machine provide several services such as WWW and USENET See also Node Network host computer 1 The primary or controlling computer in a multicomputer installation or network 2 In a network a processing unit in where a network access method resides host variable A variable in an SQL statement used for substituting data values into the statement at execution time HTML hypertext markup language The basic language that is used to build hypertext documents on the World Wide Web It is used in basic plain ASCII text documents but when those documents are interpreted called rendering by a Web browser such as Netscape the document can display formatted text color a variety of fonts graphic images special effects hypertext jumps to other Internet locations and information forms HTTP hypertext transfer protocol The protocol for moving hypertext files across the Internet Requires a HTTP client program on one end and an HTTP server program on the other end HTTP is the most important protocol used in the World Wide Web WWW See also Client Server WWW HTTP request A transaction initiated by a Web browser and adheri
415. ure 002 0000 195 sender Context Aree sie aor fale a Bob Gees a HE we Ss 196 Pool Dictionary Tips estuc p ah oroe anecs ee 197 Text Display on Update oa aaa aaa a 197 Pool Dictionary 2 2 teie m S26 eee eR gok ROK EER eee OE Di 198 Swapper Error es 424 ata dde dl ae ey ete oa 198 Hover Help Behavior aaa ee 198 Aborting a Process Stack 0 000000 eee 199 Exiting an Mago mori d a ee ee ee dees ea eck Doe Peder e we ween 199 Configured Subsystems 0 2 00 000 pee eee 199 Image Copyright o 200 Command Line Arguments 2 00000 pete 200 Run Time Image 0 2 na ee 200 EsWeakSet and Finalization 00 0020 000 4 201 Continue Background Process 4 201 Automatic Log Off ue a ta BAN AO co 202 Synchronizing a Visual Part 0 0 e 202 Execution Start orar A A A GS4 8 203 VisualAge for Smalltalk Handbook Fundamentals Inheritance of Visual Parts 0 0 0 0 0 00 0 0 a 204 Multithreading escoa a Senate a e gatia ai aia y ieh ee 204 Global Variable lt a it en e E ii AE Gea BR 205 Updating Class Attributes in a Run time Image 205 Class Methods at Run Time aaa 2 0 2 0 000 206 Objects s Knowledge of Reference 206 Smalltalk Class or AbtAppBldrPart 208 Cleaning Up Unused File Handles 208 Initializing Cla
416. urns multiple records from the remote program to the initiating object Compare to simple dialog 294 VisualAge for Smalltalk Handbook Fundamentals N NetBIOS See Network Basic Input Output System network 1 A configuration of data processing devices and software connected for information interchange 2 An arrangement of nodes and connecting branches Connections are made between data stations network address In SNA an address consisting of subarea and element fields that identifies a link a link station or a network addressable unit Subarea nodes use network addresses peripheral nodes use local addresses The boundary function in the subarea node to which a peripheral node is attached transforms local addresses to network addresses and vice versa See local address Network Basic Input Output System NetBIOS An operating system interface for application programs used on IBM personal computers that are attached to an IBM Token Ring Network network layer 1 In the Open Systems Interconnection reference model the layer that provides for the entities in the transport layer the means for routing and switching blocks of data through the network between the open systems in which those entities reside 2 The layer that provides services to establish a path between systems with a predictable quality of service See Open Systems Interconnection OSI network management The conceptual control element of a s
417. ute the pieces of abiScrublmage individually to determine what caused them to finally be garbage collected that is was it terminating any processes reinitializing the widgets or flushing the dependents If it was the dependents then the most common cause is that people send the method closeWidget rather than using the action which actually uses the method closeWidgetCommana Integer Representation Answer How can change the internal representation of Integer from 16 bit to 32 bit Smalltalk integers are not stored as 16 bit or 32 bit integers The re actually 30 bit integers until that s not enough then they grow as long as you need them to be Method Tracing Has anyone done any method tracing in IBM Smalltalk need to count actual method calls by class for a given transaction The profiler gives me only a percentage of time spent in each method based on samplings In essence what want to do is just before a method is pushed onto the stack l d like to write out a line to a text file with the class and method 216 VisualAge for Smalltalk Handbook Fundamentals Answer name currently cannot do this because get a source code not available message Yes it s certainly possible to do this The easiest way is to act like a debugger and repeatedly step through the code It s slow but it works The source code to some of the system is missing but that shouldn t matter since you don t need s
418. uture release of VisualAge or IBM Smalltalk Contrast with public class private method In VisualAge or IBM Smalltalk a method that is not part of the system API but is provided as part of the internal functioning of the system If you use a method marked as private you might have to modify your code in order for it to work with a future release of VisualAge or IBM Smalltalk Contrast with public method Individual application development projects can use the public and private designations as a means of organizing their code process In Smalltalk a sequence of actions described by expressions and performed by the system s virtual machine property A unique characteristic of a part protocol 1 The set of all messages to which an object will respond 2 Specification of the structure and meaning the semantics of messages that are exchanged between a client and a server 3 A set of semantic and syntactic rules that determine the behavior of functional units in achieving communication 4 In SNA the meanings of and the sequencing rules for requests and responses used for managing the network transferring data and synchronizing the states of network components 5 A specification for the format and relative timing of information exchanged between communicating parties proxy An application gateway from one network to another for a specific network application like Telnet of FTP for example a firewall s pr
419. wer Are there tips to follow when working with pool dictionaries Yes In general replace pool dictionary values using the at method If you replace the pool dictionary associations or the entire pool dictionary then you need to recompile all the methods that reference its values Whena method uses a pool constant the association from the pool is stored directly in the compiled method At execution time the value is taken from the association and used If you update the association value using atto the new pool will not be reflected in the execution of the code until it gets recompiled It is always best to establish pool dictionaries at load time by using toBeLoadedCode for your application Even if you cannot assign values immediately as they must be computed through the application s logic you should still build the dictionary with keys and use some form of lazy initialization to enter the values at an appropriate time This helps not only with import and export but also for loading your application into fresh images Text Display Answer on Update Why does my text not show up when update the database You can pause a process by using the Delay class but it seems like something you shouldn t have to do The typical way of coding this is as follows 1 Put up progress indicator 2 Fork background process forkAt Processor userBackgroundPriority 3 Background process calls CwAppContext default asyncExecInUl lt up
420. workaround in order to use Shift Tab to back tab through container cells Edit the key mappings for your X server If you are using X server software on a Windows or OS 2 workstation the X server software may provide dialogs to edit the keyboard mappings Use these dialogs to change the setting for Shift Tab to generate the keysym Tab For X servers running under UNIX you can run X command xmodmap to change the mappings For example to correct the mapping on an HP UX workstation run the following command xmodmap e keysym Tab Tab Tab You can run this command from your profile or other startup or logon script but it must be run after your display is specified If you are already running xmodmap you may have a resource file possibly called xmodmaprc to which you can add the above keysym expression VisualAge for Smalltalk Handbook Fundamentals Properties Views and Notebook Settings Views Tip To switch from Properties views to Notebook settings views do the following 1 From either the System Transcript or the Organizer bring up the Load Unload dialog 2 Choose to load VisualAge Notebook Style Settings Views 3 Inthe VisualAge Organizer Preferences make sure Notebook Style is selected for the Preferred Settings View Code Page Conversion Errors Tip If you are receiving errors related to code page conversion select Tools gt NLS gt Rebind Image Strings from your Transcrip
421. x About the Authors 0 00000 ee xix Acknowledgments 2 00052 bee ee eee XX Comments Welcome 000000 a xxi Chapter 1 What Is VisualAge for Smalltalk 1 Description of VisualAge for Smalltalk 1 VisualAge for Smalltalk Technology 00 4 1 Description of Smalltalk 0 0 00 00 00 2000200 2 Description of ENVY 02 2202 2 ee es 2 Stability and Maturity 0 a 2 Openness Lala DOR 2 Bes ee eben A Sew OES be Pees 3 Team or Professional Version 00 20200484 3 Advantages of VisualAge 0 0 0002 ee ee 3 Advantages of Smalltalk 0 o 4 VisualAge for Smalltalk and VisualAge Generator 5 VisualAge for Smalltalk and C aaa aaa aa 5 Visualizer pisa de Reece ee BO ee a 6 Team Gonnection sipsi iinei dh a kkk do bodani d Abe PA don out dh 6 Supported Platforms gt 2 02 24 a EAR A ace et hee 6 Smalltalk Strategy 0 2 00000 ee 7 Smalltalk and Java ane pe iawa AET a a an 7 Configuration Management a 7 Packaging Support iy s cinco ani a bolari adip Re i bah E 8 Da taba s Support seses a nurete A BEE A esa de tt AA 8 Communication Protocol Support aaa a 8 Legacy Code 2 ia e e a o a aa a a a a ALa 9 Runtime Distribution Fees 0000000000004 9 Distributing Smalltalk Compiler 2 48 9 Source Cod
422. y classes still owned by the user Select Queries gt Classes Owned By from the Smalltalk Tools menu Finally purge the user You should also understand how you got into this situation There are two inportant parts to a user 1 The external name This is what you see in the browsers and this does not have to be unique 2 The unique name This is used by the system to differentiate users In your case the users have unique underlying names but their visible names happen to be the same If you wish you could simply change the visible name as described above The lesson to learn is that you should not define new users without making sure that the unique names are consistent The easiest way to do this is to export and import the users explicitly or to allow the definitions to come over as a byproduct of code import or export VisualAge for Smalltalk Handbook Fundamentals Classes Available in the Library Answer Is there any way to develop a snooper that can be used to compare the loaded classes against what is available in the library A function like that would provide the user with the capability of selectively picking up fixes on a periodic basis into an existing image Is it feasible to develop such a utility that could be run on demand The Team version release control features give you the functionality that you are looking for The way you can work with it is to have configuration maps for the various major compo
423. y dots sometimes called a dotted quad For example 198 204 112 1 Every Internet computer has an IP number and most computers also have one or more domain names that are plain language substitutes for the dotted quad ISDN Integrated Services Digital Network A set of communications standards that enable a single phone line or optical cable to carry voice digital network services and video ISDN is intended to eventually replace our standard telephone system iterative development A software development process that allows progress in stages At the end of each stage the result is verified by end users Through such verification requirements are dynamically identified and refined while the product is under development J Java Java is a new programming language invented by Sun Microsystems that is specifically designed for writing programs that can be safely downloaded to your computer through the Internet and immediately run without fear of viruses or other harm to your computer or files Using small Java programs called applets Web pages can include functions such as animations calculators and other fancy tricks We can expect to see a huge variety of features added to the Web using Java since you can write a Java program to do almost anything a regular computer program can do and then include that Java program ina Web page job control language JCL A problem oriented language designed to express statements in
424. you and if you are in the Team environment it is probably best to get a new image and reload your application We have seen this before and that is the fastest and best way to get rid of it Synchronizing Attributes Answer have two classes A and B and make an attribute to attribute connection of one attribute in class A to another attribute in class B Suppose have methods in both classes that reference these two attributes When the attribute of A or B changes do these methods get executed simply because they reference by using the getSe ector these two attributes With an attribute to attribute connection class A will signal in a method that its attribute has changed using the changeSymbol defined for the attribute Smalltalk self signalEvent attributeOfAChanged Chapter 2 General Information 45 Keeping the This signaling of the event will cause the AbtAttributeToAttributeConnection to get the value of class A s attribute using the getSe ector defined for it and set the value in the instance of class B using the setSe ector defined for class B s attribute Packaged Image Small Image size is a fundamental problem when it comes to running on restricted resources Keep in mind that VisualAge uses substantial amounts of DLL code most probably more than the image size Anyway the packager will do its best to get rid of any superfluous classes and methods but you can do a few things that mi
425. you d get a hit whenever there was activity focus change keystrokes mouse active etc The drawback of this approach is you d be modifying the base image Not a crime but means you own it Synchronizing a Visual Part 202 Answer How do synchronize a visual part with the Smalltalk object it is called from If you simply want to wait in a script for a window you opened to be closed the easiest way is to use Smalltalk myWindow openWidget myWindow suspendExecutionUntilRemoved whatever you want to happen after the user closed the window The user interface process has the same restrictions as Presentation Manager PM that is you must return to the polling loop or the user interface UI will lock Therefore you cannot block on a semaphore in the UI process if you do you Il lock the UI if the semaphore is not posted quickly When you execute code from a Workspace with Execute that code is evaluated in the UI process An example is Semaphore new wait If select and execute this the UI will lock press and hold Alt SysRq or press the User Break button on Windows 95 NT AIX to unlock However if fork around it it doesn t lock because it is not running on the UI process VisualAge for Smalltalk Handbook Fundamentals don t understand why you need to stop the user interface but if you must here s a safe way Smalltalk keep waiting condition whileTrue CwAppContex
426. ysis and design with VisualAge for Smalltalk refer to Visual Modeling Technique Copyright IBM Corp 1997 XV How This Redbook Is Organized xvi This redbook contains 362 pages It is organized as follows Volume 1 Fundamentals This book sets the stage for programming with VisualAge for Smalltalk It contains questions and answers dealing with the base product and everyday programming pitfalls Chapter 1 What Is VisualAge for Smalltalk This chapter provides some non technical discussion of programming with VisualAge for Smalltalk Chapter 2 General Information This chapter provides general programming tips from image maintenance and packaging to troubleshooting Chapter 3 Graphical User Interface This chapter provides a discussion of graphical user interface parts such as containers notebooks buttons or tables Chapter 4 IBM Smalltalk Programming Language This chapter provides questions and answers regarding the IBM Smalltalk programming language Chapter 5 ENVY This chapter provides a discussion of the ENVY team programming environment Chapter 6 Microsoft Windows This chapter provides a discussion of programming issues related to the Microsoft Windows platform Chapter 7 National Language Support This chapter discusses national language support with VisualAge for Smalltalk Volume 2 Features This book details on the various VisualAge for

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