a design pattern generation tool - Worcester Polytechnic Institute
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1. Subject attach in Observer detach in Observer notify _ for ob observers ob Update ConcreteSubject subjectState GetState _ SetState ES subject ConcreteObserver Update _ observerState subject GetState return subjectState FIGURE 6 OBSERVER PATTERN OBSERVER PATTERN This pattern works if some object needs to know about the state of another object Continually polling the object wastes processor time so the object waits for the other object to notify it This pattern improves on that by allowing the notification to go out to many waiting objects at once As the diagram shows the Subject has some way for the Observer to subscribe to it In this case the attach method will perform the subscription When an event occurs the Subject starts to notify its list of subscribers To notify a specific subscriber it runs that subscriber s Update method The Update method defines what the subscriber does after the event 16 For example assume a Bear object should eat Girl when the Girl s location equals woods To use this pattern the Bear would subscribe to the Girl and the Girl would notify all its subscribers including the Bear when its location changed When the process reached the Bear the Girl would call the Bear s Update method which would include the action of checking the Girl s location and depending on the location eating th2. class RealObjectl private double dub 8 5 public double dol return dub class RealObject2 private double dub 10 5 public double dol return dub class RealObject3 private double dub 11 5 public double dol return dub class Main public static void main String args RealObjectl objl new RealO0bjectl RealObject2 obj2 new RealObject2 RealObject3 obj3 new RealObject3 33 becomes public abstract class AbstractObject public abstract double dol class RealObjectl extends AbstractObject private double dub 8 5 public double dol return dub class RealObject2 extends AbstractObject private double dub 10 5 public double dol return dub class RealObject3 extends AbstractObject private double dub 11 5 public double dol return dub public class AbstractFactory public enum ObjectType RealObjecti RealObject2 RealObject3 34 public static AbstractObject creat ObjectType type switch type case RealObjectl return new RealObjectl case RealObject2 return new RealObject2 case RealObject3 return new RealObject3 throw new IllegalArgumentException The type type is not recognized class Main public static void main String args for ObjectType type ObjectType v
3. It was small containing only five patterns but it was new at the time Beck amp Cunningham Later pattern languages expanded the list to include more languages One ambitious project listed and categorized 23 patterns completed by a group who would become known as the Gang of Four Erich Gamma Richard Helm Ralph Johnson and Paul Vlissides The patterns were categorized as 12 e creational patterns that is patterns that deal with class instantiation e structural patterns that deal with class and object composition and e behavioral patterns that deal with communication between objects Erich Gamma 1995 As an analogy a book on pattern language is simply a dictionary Software designers constantly add new patterns just as speakers of a language constantly add new words So while the Gang of Four patterns remain the classic patterns far more exist In particular the GoF misses an entire category of patterns concurrency patterns These patterns offer solutions to scenarios involving multiple threads Schmidt Stal Rohnert amp Buschmann 1996 Continuing the analogy of a pattern language to a dictionary the patterns needed a meaningful definition LePUS3 is a design description language especially designed to model the classic design patterns The language is flexible enough to also define other patterns and similarly code not involved in any pattern The premise of the language represents each object with
4. Real bject2 d nealobject2 RealObject3 oF RealObject3 Wizards E Class Interface e Java Project Java Project from Existing Ant Buildfile 35 Plug in Project amp C General E SO E amp Design Pattern New Design Pattern E Java gt Annotation Class G Enum E 35 Debug E console 22 Interface SZ Er ETE No consoles to display at this tir O Back Next gt Finish Cancel io Writable Smart Insert Si tatement do Recent Unread Topic Java edu wpi patte FIGURE 10 OPEN DESIGN PATTERN NEW DESIGN PATTERN The Design Pattern Wizard will appear Choose the appropriate pattern and language and click Next Bear in mind that only Adapter Abstract Factory and Observer in the pattern selection and Java in the language selection will display the appropriate behavior 26 Java Test src test java Eclipse SDK F Edit Sour Refactor Naviga earch Pro Sample Menu Run Wwindos elp det O Q 8H6 Bg PAi Hgs Or E SJ Java Browsing g gt x E DES outine E e E EAZ GA dd test ST Realobjecti SF Realobject2 SF Realobject3 I Package Explorer Ei i 0p B public enum test E Real0bjecti Design Pattern RealObject2 Choose which pattern you want to apply RealObject3 E E Test Choose pattern Has Choose language lava M 35 Debug DI console E No consoles to display at this tir Cancel
5. Computer Science sus 12 Classic Design Patterns Ea a ea Sd udi terc e fue 12 HEROE cla 13 CPU erta a e arle 13 About the patterns used in the Pattern Wizard sens 13 e Ee 13 Abstract Ee ee civ white ca ereak EA baitaite 15 IEN 16 About Eclipse plugis ia REA A po ena endete tied 17 Pattern dvA lu eege geet EE aaa 19 A OO 19 How to add more pattern 20 Where does it go from here ii don 21 Additional OMV EE 23 Version HIS Y cta 23 Project Timetable iii A Ea a ata 23 Appendix A User Manual a 25 Appendix B Adapter Pattern Use Cases iii 29 Case 1 Initial implementation sn 29 Case 2 Use existing interface scettr te dra elena 31 Appendix C Abstract Factory Use Case iii 33 Appendix D Observer Use seed 36 Bibliography cpi be cre del re ae e edd D Bout t aa 39 TABLE OF ILLUSTRATIONS Figure 1 PatternBox Screenshot garaierara arara 8 Figure 2 DPA Toolkit Screenshot sr ENEE 10 Figure 3 Adapter Pattern Adapter Class Pattern 14 Figure 4 Temperature example e pb e p e A AA af alaia 15 Figure 5 Abstract Factory Pattern Abstract Factory Pattern 15 Figure 6 Observer Pattern Observer Pattern nine 16 Figure 7 Eclipse architecture sen 17 Figure 8 Pattern wizard structure nn 19 Figure 9 Click New gt Other teen te ae Rete Die etr e nei tue epic 25 Figure 10 Open Design Pattern gt New Design Pattern re 26 Figure 11 Select Pattern and Language urnes 27
6. rectangles The rectangle representing the object lists all the methods in that object Dotted lines represent relationships such as calls creates and other soft connections A solid arrow pointing in the direction of the parent represents inheritance LePUS3 and ClassZ Reference ABOUT THE PATTERNS USED IN THE PATTERN WIZARD Adaptee SpecificRequest Request 2 SpecificRequest FIGURE 3 ADAPTER PATTERN ADAPTER CLASS PATTERN The adapter pattern translates the interface of a class into one useful to the program It breaks the connection between the calling method and the implementation Practically this would adapt code quickly to previously written classes This diagram shows how to do this The calling method Client would ordinarily directly make the SpecificRequest in the Adaptee Instead it places a request through the Adapter which determines the appropriate target and makes the request to them One example of an application of the Adapter is a weather tool that uses the Fahrenheit scale Different functions on Fahrenheit temperatures are a separate class from the weather client The adapter pattern works here to apply previously written code that returns temperatures in Celsius Then the weather client would call the general Temperature interface If the appropriate method uses Fahrenheit it simply returns the value of the desired method If the appropriate method us
7. this case with a list of methods in one file which will need to be matched to methods from another file Do this by selecting the method from the drop menu then click Finish 28 APPENDIX B ADAPTER PATTERN USE CASES CASE 1 INITIAL IMPLEMENTATION Object dolt Gass J Lets do24 2 Las Client Object obj opz dol fe eei obj do2 becomes Object Gol ea zi E e dra iObject Gol is dee d z taas es 29 Adapter implements iObject Object obj Adapter Object newObj obj newObj dol obj dol do2 obj do2 Client Object obj Adapter adapter new Adapter obj adapter dol adapter do2 7 30 CASE 2 USE EXISTING INTERFACE NewObject makeOne makeTwo makeThree Client NewObject obj obj makeOne obj makeTwo iObject dotado Kaal A A 12 becomes NewObject makeOne makeTwo makeThree iObject 31 dod so Dese dolls Tos Adapter implements iObject Object obj Adapter Object newObj obj newObj dol obj makeOne EIG berek d obj makeTwo Client Object obj Adapter adapter new Adapter obj adapter dol adapter do2 7 32 APPENDIX C ABSTRACT FACTORY USE CASE
8. D Writable Smart Insert 6 1 tg Start D Mission Statement do The Etiquette of Fat Java edu wp FIGURE 11 SELECT PATTERN AND LANGUAGE Next the wizard will request pointers to previously existing code Click Browse to bring up a dialog Navigate to the file containing the code click on the file and click Next If the file is blank the wizard will write a template for the pattern into that file Otherwise it will read in the code and make the appropriate changes Some files are optional When enough information has been gathered either the Next button or the Finish button will be unblurred Click either one to continue 27 Java Test src test java Eclipse SDK File Edit Sour Refacto Era T edi con Use adapter pattern P opentest E Package Explorer 22 P Fill in roles of adapter pattern d Meditors BS Test Fe Que My Recent EEE Client Documents F Object E Adapter Interface Desktop My Documents My Computer Activator java My Network java 35 Debug El Console 23 No consoles to display at this time de inis ne Zi Writable Smart Insert 6 1 rs Start T Mission Statement do lulu Buffy the Vam Java edu wpi patte E Java crosoft Out FIGURE 12 CHOOSE CODE FILES Some patterns such as the Adapter pattern need to identify methods as well as classes There will be another page in
9. Figure 12 Choose daaa UAE 28 INTRODUCTION This project attempts to answer two questions 1 Cana tool be designed that can convert a design pattern template into usable code regardless of the purpose or structure of the code 2 Can that tool analyze code and determine the appropriate use of a design pattern Design patterns help improve programmer efficiency Several open source tools are available to create design pattern templates for the programmer to fill in with relevant code PatternBox PatternBox 2009 is one example of these tools This project determines whether tools of this type can be extended to apply patterns to previously written code and automatically determine suitable patterns for the given code The success of the Pattern Wizard depends on the variety in language and function of programs which are compatible with the tool There should be minimal constraints on the Pattern Wizard s use Additionally the ratio of user input in the form of code and annotation to the tool s code output should be as low as possible HOW DID THE PROJECT EVOLVE The project began as a two person project Galia Traub and I meant the project to explore the differences in design patterns across different programming paradigms While design patterns started as object oriented in nature we believed that design patterns could be used in other paradigms as well such as functional and procedural To increase the scope of the pr
10. Project Number GFP 0801 A DESIGN PATTERN GENERATION TOOL A MAJOR QUALIFYING PROJECT REPORT SUBMITTED TO THE FACULTY OF WORCESTER POLYTECHNIC INSTITUTE IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF BACHELOR OF SCIENCE BY CAITLIN VANDYKE APRIL 23 2009 APPROVED PROFESSOR GARY POLLICE ADVISOR ABSTRACT This project determines the feasibility of a tool that given code can convert it into equivalent code e g code that performs the same task in the form of a specified design pattern The goal is to produce an Eclipse plugin that performs this task with minimal input such as special tags The final edition of this plugin will be released to the Eclipse community ACKNOWLEGEMENTS This project was completed by Caitlin Vandyke with gratitude to Gary Pollice for his advice and assistance as well as reference materials and troubleshooting TABLE OF CONTENTS Prisc 2 Acknowlegements siii rn aa AA aA aiak aka H Table OF Contents usino iii nn 3 Table ell St DIOE au aaa a a aA ab AA 5 Introduction EE 6 How did the project SOIS a 6 Why is this helpful 5 eerte ette rade EES 7 Backgro nd ehe cune p hae manti tete anu RA eun ant anm UE 8 Previous WOE ei tddi 8 Patt RnbDOX em 8 Design Pattern Automation Toolkit eiiis e 9 AlphaWorks Design Pattern Toolkit a 11 Design EIL GO a ketara eo adan 11 Original Ses Re A A RE eae ducet d 11 Design Patterns in
11. alues System out println ObjectType ObjectFactory create type dol 35 APPENDIX D OBSERVER USE CASE interface Observer void update Subject sub interface Subject void attach Object o Object detach Object o void notify becomes import java util ArrayList interface Observer void update Subject sub interface Subject void attach Object o Object detach Object o void notify public class RealObserver implements Observer 36 private RealSubject sub public RealObserver RealSubject sub this sub sub sub attach this public void update Subject sub TODO React to change public class RealSubject implements Subject private ArrayList observers new ArrayList public void attach Object o observers add o public Object detach Object o observers remove o public Iterator iterator return list iterator 37 private void notify Iterator i observers iterator while i hasNext Observer o Observer i next o update this 38 BIBLIOGRAPHY Abstract Factory Pattern n d Retrieved March 19 2009 from The LePUS3 and ClassZ Companion to the GoF http www lepus org uk ref companion AbstractFactory xml Adapter Class Pattern n d Retrieved March 19 2009 from The LePUS3 and Cl
12. assZ Companion to the GoF http www lepus org uk ref companion Adapter Class xml Alexander C 1977 A Pattern Language Oxford University Press Avgeriou P 2005 Architectural Patterns Revisited Beck K amp Cunningham W 1987 Using Pattern Languages for Object Oriented Programs OOPSLA 87 Bolour A 2003 July 3 Notes on the Eclipse Plugin Architecture Retrieved April 20 2009 from Eclipse Corner http www eclipse org articles Article Plug in architecture plugin architecture html Gamma E et al 1995 Design Patterns Elements of Reusable Object Oriented Software Reading Addison Wesley LePUS3 and ClassZ Reference n d Retrieved April 20 2009 from LePUS3 and ClassZ http www lepus org uk about xml Observer Pattern n d Retrieved March 19 2009 from The LePUS3 and Class Z Companion to the GoF http www lepus org uk ref companion Observer xml PatternBox 2009 February 8 Retrieved April 23 2009 from PatternBox http patternbox com 39 Schmidt D C Stal M Rohnert H amp Buschmann F 1996 Pattern Oriented Software Architecture Wiley 40
13. e Girl ABOUT ECLIPSE PLUGINS wee EcipseSDK mm mm N Workbench IDE Eclipse Platform Java Development Tools DT Plug in b Development Environment PDE Y D lt Platform Runtime based on OSGi d ui GO FIGURE 7 ECLIPSE ARCHITECTURE Eclipse is a software development platform supporting Java It is intriguing in the fact that it supports user developed plugins to add functionality Since the purpose of this project relates to adding functionality on an IDE level this is an appropriate form for the Pattern Wizard 17 Eclipse provides the extension points to support plugin development Among these is the Wizard class which generates a set of pages with prompts that the wizard displays if a particular action is completed Eclipse also supports adding new types of file visual input and new menu actions Eclipse maintains information on its plugins through a manifest file specific to each plugin This manifest file is stored in xml format in Eclipse s plugin folder So Eclipse has a list of available plugins at all timeswhich is referenced on starting Eclipse The manifest file stores information about each plugin including a unique identifier and a list of extension points which reference ways the user accesses the plugin s functionality These can also be parameterized to distinguish between user calls in different contexts Bo
14. ends WizardPage implements Listener ma t static final int OBS static final int SUB 0 1 i static final int ATTACH 0 static final int DETACH 1 static final int NOTIFY 2 static final int UPDATE 3 String root String obsName CN d se Project ShowIn Aleshiftew I Project B cop ES Package ES py Qualified Nam Sj Class Paste Gi 6 Interface X Delete Delete G Enum 5 Annotation Detach Notify Update Ba Import 4 amp 5 Source Folder E r Export C Folder Fil Sep l f Refresh FS 3 File P E Untitled Text File erte Alt Ent ES Unt Test Case Path Locat Type b b Warnings 100 of 2 Ctri N What if being PA is th 9 04 AM FIGURE 9 CLICK NEW gt OTHER When the New Dialog appears click on Design Pattern gt New Design Pattern Then click Next 25 Java Test src test java Eclipse SDK File Edit Source Refactor Navigate Search Project SampleMenu Run Window Help i Ee E id dr Orr CAT dr i PLA dz dir dr ES Ei Java Browsing ZT Package Explorer werner Gi Ur Outline 23 I Packa BN 2 Bp BE outine Sr Fm SE z ARTZE J public enum test a O m3 El gt Test i a test Rea10hject1 Select a wizard gt dE Goen
15. es Celsius it would convert the return value into Fahrenheit before returning it 14 Fahrenheit Client Adapter Celsius FIGURE 4 TEMPERATURE EXAMPLE AbstractFactory AbstractProduct B CreateProductA LN CreateProductB A A La Product A2 I create ConcreteFactory2 CreateProductA CreateProductB Product B2 create ConcreteFactory1 q p 7 J CreateProductA CreateProductB 1 create Product B1 The abstract factory pattern allows the creation of multiple objects with identical interfaces Like the adapter pattern it separates implementation details from their usage However this applies to objects specifically instead of methods The diagram shows the structure of this pattern The AbstractFactory defines the objects that the user wants to create The clients call on the AbstractFactory for ProductA or ProductB Either ConcreteFactory1 or ConcreteFactory2 will act on that request and return an AbstractProductA or 15 AbstractProductB However the pattern keeps the client unaware of which factory and therefore which particular implementation created the product For example if the client needed a paper it would call on a PaperFactory to produce it Either EssayFactory or ResearchPaperFactory will actually create the Document and then return it However the client has no knowledge of which factory created its paper
16. fine your own code templates The current plug in version includes 16 design patterns of the Gang of Four GoF This tool works by generating a special file to represent the pattern Inside the file choosing an element of a pattern brings up a way to choose the location of the element Once the user completes this process the tool generates sample code of that element of the pattern This differs from the Pattern Wizard by only creating code never modifying it Modifying code requires reading and parsing the input which increases the complexity of the program Fi Vew Tous res teow teen Gta recio rennes gt MyConponent FACTORY METHOO OBSERVER FIGURE 2 DPA TOOLKIT SCREENSHOT This tool can be downloaded from http dpatoolkit sourceforge net According to the web site DPAToolkit is a tool to help in software development via design patterns The design can be visualized via class diagrams and design patterns can be incorporated into the design easily Dpatoolkit comes with all the 23 Gang of Four design patterns which can be easily added in the design Apart from these users can develop their own design pattern plugins and add them in their designs or share with others The design patterns are saved in XML format Dpatoolkit comes with the following code generators CA C Java VB NET New code generators can be easily plugged into the application 10 This tool displays the use of design patterns in mu
17. ic IPage to convert code Version 5 Parses user code to implement pattern Version 6 Parses user code to implement three representative patterns Version 7 Clean code and documentation PROJECT TIMETABLE September October Research on Design Patterns and previous attempts October Created versions of the Adapter pattern in all paradigms Researched code parsers November Researched Eclipse plugins and how to make them December January Wrote Pattern Wizard framework February Added Adapter pattern to Pattern Wizard March Added Abstract Factory and Observer patterns 23 April Wrote report and documented tool 24 APPENDIX A USER MANUAL I designed this tool for use with Eclipse IDE Once Eclipse loads right click in the File Explorer then click New gt Other Alternatively press Ctrl N Java edu wpi patternmaker v6 src edu wpi patternmaker v6 patterns observer ObserverMatchPage java Eclipse SDK File Edit Source Refactor Navigate Search Project Run Window Help iwi Mitr Dr Q GE Zr ES dr iG iT Aid to n PERS E D observerMatchPage java Ai Combo class 8 Bei package edu wpi patternmaker v6 patterns observer edu wpi patbernmaker import java io BufferedReader du wpi patternmaker du wpi patternmaker edu wpi patternmaker edu wpi patternmaker amp Jo gt edu wpi patternmaker E 33 ExampleComSnippetsPlu 8 I OpenTest public class ObserverMatchPage ext
18. ich displays a choice of patterns and languages Based on that input the wizard generates a new page and presents it to the user on clicking the next button This new page prompts the user to add files to the pattern in different roles depending on the specific pattern This page is named lt Pattern gt MainPage where lt Pattern gt was the specific name chosen If the wizard requires more information to generate the pattern control then passes to another page of the wizard This page is named lt Pattern gt MatchPage in the sense that the user matches information to the pattern In either case the last page makes the required modifications to the code and returns control to the PatternWizard to close the tool HOW TO ADD MORE PATTERNS To add a new pattern consider what a beginner programmer would write in a situation where the pattern would be appropriate With this in mind write a document for what parts of the code would be used to implement the pattern Also note whether any judgment calls would be required by the user Create a new package edu wpi patternmaker lt Version gt patterns lt Pattern Name gt In that package create a lt Pattern gt MainPage object which extends IPage Depending on whether the pattern requires another page to take additional information define e Int numElements the number of source files required from the user e String roles numElements the labels for inputting the sou
19. lour 2003 18 PATTERN WIZARD For practical information on the Pattern Wizard see Appendix A the User Manual STRUCTURE ralor PLUGIN ID numEloments shor role Te reap broure qetDofaul aotlmaqeDorcripte sreateCantre handloEvent canFlipToNoxtPaq irPaqoComplote S ENUM canFlipTaNextP aa AOEJ qothoxtPaq enumbame abrObiNamo root abjostr GO aNextPags CLIENT andloEver OBJECT INTERFACE commanMethadLis abjoctMothadLis qonorateF actor interfacoNam parreCade interfacoP at aotitoms abjoctName adapterHame adaptorPatl tarqe matck OBS SUB ATTACH DETACH NOTIFY UPDATE root abrName srubHamo abrMothadr subMothadr standardMothod methadLabelr matchor qoneratelnterfa fillint FillObiec parreCade qexM addLirtonors doFinirh madifyClior qenerateAdapte handloEvent irPagsComplete createCan initi aetSubMethad qetObrMethodr parreCade getti addLirtonors doFinirh handloEvont irPaqoCamplote qenerateObrerve eSubie Demum rothictivePa runes D relostionChanqe S canFinirh erfarmFinir irComplotod rotMadel aetMadel zetCumpletec tarqe ZA 1 Ahadol mainPage TT sa uarkbenck rolectiar nextPaqe patter language time Stats dortinatianStat pattern addLirtonora handloEvont raveDataToModel actMextP aq FIGURE 8 PATTERN WIZARD STRUCTURE 19 Control starts with the PatternWizard object It passes control to the main page wh
20. ltiple languages an idea I hoped I could implement with the Pattern Wizard It also has a way to create new design patterns other than the GoF patterns from the client side using a pattern description language However this tool does not modify existing code to fit the pattern it only generates it This tool can be downloaded from http www alphaworks ibm com tech dptk download This is an Eclipse plugin along the same lines as PatternBox Again this tool does not modify code but it does more than generate a blank pattern template From the web site The pattern can be thought of as a transformation between the input application definition and the complete set of generated source artifacts There are template tags that let you transform the application definition into an intermediate XML form and then navigate that XML to drive the generation of source artifacts Each source artifact is generated as a result of applying the modified application definition to a specific pattern template Each pattern template contains a set of static or boilerplate code interspersed with template tags that direct and define the merging of the application definition with the template DESIGN PATTERNS Design patterns were originally meant as handy solutions in physical architecture Christopher Alexander first published a book on the subject describing useful patterns for designing and building This included patterns to design an entire com
21. munity from farmland to shopping centers to places of worship and cemeteries Alexander 1977 11 In addition this book explained similar patterns to design groups of buildings like a mansion or school arrange rooms in a house according to their purpose and landscaping outside the building Alexander 1977 Alexander s work became useful in the growing field of computer science A design pattern defines a general solution to acommonly occurring problem written as a template or as a set of relationships In computer science this translates to a coding template or an object diagram representing a known solution to a common task Like algorithms design patterns are a tried and accepted solution as such people develop and adapt them instead of discovering them They both represent an approach to a problem more than the specific implementation of the solution However they differ in purpose algorithms optimize the cost of a solution while design patterns optimize its clarity Architectural patterns are also similar to standard design patterns however architectural patterns focus more on entire systems of programs as opposed to just one This is a subjective difference in some cases design patterns have been used as architectural patterns They both look at the structure of code in the context of relationships Avgeriou 2005 The first pattern language in computer science was developed by Kent Beck and Ward Cunningham
22. oject we also attempted to write a tool demonstrating how code would change for each pattern in each paradigm and create a language to define design patterns regardless of paradigm if it proved possible or alternatively to define design patterns in the other paradigms individually The goals became two different projects due to differences between the topics This project evolved from the code tool reduced in scope for a single student The number of patterns to integrate into the project caused the scope to be reduced to three representative patterns Because of time concerns I further reduced the project to representing the object oriented application of the pattern As a result the only language currently compatible with the Pattern Wizard is Java However this project serves as a proof of concept and a starting point for further work WHY IS THIS HELPFUL I designed the Pattern Wizard with a beginner programmer in mind Because the tool converts basic code into a form that uses a design pattern a programmer can analyze how the pattern works without needing to write an implementation If the process of implementing a pattern becomes easier the focus can shift from how to write an implementation of the pattern to where in the code to use the pattern Allowing the user to write code before applying the pattern increases the number of scenarios where the tool would be appropriate for instance the tool could be used on third par
23. rce code locations and 20 e Text role numElements the locations of the source code if there only needs to be one page and also e lt Pattern gt NextPage nextpage if the pattern needs more than one page You will also need to implement e canFlipToNextPage indicating when enough information has been entered for the wizard to continue to the next page false if there is no next page e handleEvent checking whether the user fully completed the current page and updating the wizard e isPageComplete checking whether all of the required elements have been filled in supports handleEvent and canFlipToNextPage if the pattern uses multiple pages e doFinish which parses the given code and rewrites it as the design pattern and also e getNextPage which initializes the next page e createControl which describes the next page if the pattern uses multiple pages WHERE DOES IT GO FROM HERE Further study on this topic can progress in several directions Researchers can increase the number of patterns supported by the Pattern Wizard More information can be found below for 21 instructions on how to do this Additionally other projects can cover the multi paradigm approach or the description language or the pattern catalog 22 ADDITIONAL INFORMATION VERSION HISTORY Version 1 PatternBox source code Version 2 Generic Eclipse wizard Version 3 Retrieves code from user Version 4 Uses gener
24. ty code and the Adapter pattern to insert it into a project in progress BACKGROUND PREVIOUS WORK For the first step in this project I researched other approaches to this problem both to find a starting point and to evaluate the uniqueness of my approach PATTERNBOX IC observer xdp El gt EE Define a one to many dependency between objects so that when one object changes state all its dependents are notified and updated automatically Subject 1 1 664 J observer Subject sens gt Observer 1 1 J observer Observer gt ConcreteSubject 1 1 Browse J observer ConcreteSubject E ConcreteObserver 1 PS E Ol eteObseryi bizie J observer ConcreteObserver2 E E State 1 1 J observer State Main Source FIGURE 1 PATTERNBOX SCREENSHOT This tool can be downloaded from http patternbox com According to the web site PatternBox is a design pattern editor for Eclipse It creates Java classes and interfaces that can be customized depending on your application needs Using PatternBox you have freedom and flexibility to insert new pattern members whenever you want PatternBox offers a template based code generator The generator makes intensive use of Eclipse s Java development tooling JDT and the Plug in Development Environment PDE Both features must be available to run the plugin The XML based template mechanism makes it possible to de
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