Developing Applications with the Eclipse RCP.pdf

102 – Developing Applications With the Eclipse Rich Client Platform (RCP) John Arthorne & Chris Laffra IBM Rational http://eclipsefaq.org/{john,chris} Tuesday, Aug. 30, 9:15 a.m. – 10:45 a.m.

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Session Abstract 

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When many people think of Eclipse, they see a Javacentric development environment. But there's more to Eclipse than Java—you now have several languages and protocols from which to choose. The Eclipse versioned plug-in architecture lets developers easily add new components, including language support for C++, PHP, Fortran, Web services and others. In this session, we will show how easy it is to write your own rich client applications based on the Eclipse Rich Client Platform (RCP). We will guide you through the various parts of the Eclipse RCP infrastructure that are available as building blocks for your own applications

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Roadmap  Introduction  Rich Client Programming  The Eclipse RCP Project Examples of RCP applications Quick tour of RCP APIs Building your own Eclipse RCP application

 Conclusions

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Source of Materials  Material sources:  My head  RCP tutorials at eclipse.org  RCP samples from eclipse.org  Feedback from Eclipse committers  The Official Eclipse 3.0 FAQs 

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Format  Question and answer format  We will introduce  Some background; what is a Rich Client?  The Eclipse project and RCP Quick tour of Eclipse RCP plugins with sample code

 After this presentation, you should be able to develop your own Eclipse RCP application.

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What is a Rich Client?  Google dictionary: “A computer program that can download files for manipulation, run applications, or request application-based services from a file server.”  Need some form of ‘installation’.  Not a Thin Client (like a Web site).  A ‘client’ with rich UI and interaction

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Rich Client Examples      

Java Applets in a browser JavaScript applications (e.g., Bindows) J2ME MIDP Midlets on a phone/PDA Macromedia Flash MX Microsoft Foundation Class (MFC) apps Eclipse Rich Clients

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Rich Client Criterias        

Support for various platforms Ease of installation Look-and-Feel The ‘Richness’ of the solution Interoperability with other solutions Tooling support Performance Mind-share (following the current trend) © 2005 IBM

The Eclipse RCP in a nutshell  The Eclipse Rich Client Platform is a subset of the Eclipse platform designed for developing Rich Clients written in Java, using the Eclipse plug-in model for defining individual components using XML manifests.  Open Source, free.  Uses SWT for close-to-native feeling

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Eclipse RCP sample 1 Maestro – NASA Space Mission Management Shown at EclipseCon 2005

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Eclipse RCP sample 2 IBM Workplace Client Technology, Client Administrator Shown at EclipseCon 2005

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Eclipse RCP sample 3 Schoolclipse – Greek school management software

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Eclipse RCP Motivation  Modular approach, using plug-ins written in XML and Java. Connections between plug-ins are loose.  Lots of open source plug-ins easily added to your application  Eclipse behaves like a native application (due to SWT).  Eclipse is a framework. Lots of lessons learned and decisions have been made for you, leaving you more time to focus on your value add. The learning curve will pay off.  Upgradeability. Use plug-ins to upload content handlers, and provide users with a given set of abilities and plugins based on their credentials.  Versioning. Plug-ins are versioned, platform manages them. © 2005 IBM

What is Eclipse? An open IDE platform for anything, and for nothing in particular.  Open: allows for easy extension by third parties.  IDE: tooling to manage workspaces; to build, launch and debug applications; team sharing; easy customization of the programming experience.  Platform: not a finished application  Anything: Java, Web-services, games, etc.  Nothing in particular: Java focus is historical. © 2005 IBM

Where did Eclipse RCP come from?  Core of OTI/IBM products since late 90’s  VisualAge Micro Edition (written in Java, first use of SWT)  VAME framework generalized into Eclipse  Eclipse open source project, Fall 2001  Community began tearing it apart to build things other than language tools  Eclipse RCP released in June 2004 (part of Eclipse 3.0) © 2005 IBM

What articles are there?  More than 60 at http://eclipse.org/articles  Printable format is over 500 pages  Covers wide range of Eclipse topics; from SWT to preferences to RCP to Wizards to style guides to internationalization to editor support to using CVS branching.  IBM DeveloperWorks also hosts a few dozen articles on Eclipse and products

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What books are available?  More than 28 were counted in July 2005  Many are introductory with wide coverage  Others focus on vertical domain (SWT, EMF)  Eclipse RCP Book: October 2005, Jeff McAffer and JeanMichel Lemieux © 2005 IBM

Where to download Eclipse?  Eclipse.org/downloads:     

Latest Release tested, may be 6 months old Stable/milestone build, 6 weeks apart Integration build, each week Nightly build, mileage varies directly from CVS, not for the faint of heart

 Builds are tested and results are posted

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Eclipse Supported Platforms        

Microsoft Windows 2000/XP Red Hat Enterprise Linux SuSE Linux 8.2 Sun Solaris 8 SPARC Motif HP HP−UX 11i hp9000 IBM AIX 5L PowerPC Motif Apple Mac OS X 10.3 SWT also on QNX Photon and Win CE © 2005 IBM

How to upgrade Eclipse?  Use the included Update Manager  works for Eclipse IDE and RCP  upgrade existing plug-ins to later versions  install new plug-ins from third party locations

 Allows you to build a rich client and have extensions added later (like content handlers or additional business logic)

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Where to get Help?  Included in your plug-ins/application: Help > Help Contents… F1, context-sensitive help Can be added to an RCP application

 During development: http://eclipse.org (articles, newsgroups, etc) Books, tutorials, portals “Use the source, Luke!”

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What is a plug-in?  An encapsulation of behavior that cooperates with other plug-ins to construct a program  Plug-ins typically consists of: Manifest, described in plugin.xml Icons and resource bundles Java code in one or more jars

 In Eclipse, everything is a plug-in

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What is the plugin.xml file?  Here is an example: Preference pages and three Eclipse articles on Preference pages © 2005 IBM

Using an ImageRegistry  

Images are OS resources that need to be managed carefully to avoid waste & leaks Here is an example:

public class ExamplesPlugin extends AbstractUIPlugin { public static final String PLUGIN_ID = "org.eclipse.faq.examples"; public static final String IMAGE_ID = "sample.image"; ... protected void initializeImageRegistry(ImageRegistry registry) { Bundle bundle = Platform.getBundle(PLUGIN_ID); IPath path = new Path("icons/sample.gif"); URL url = Platform.find(bundle, path); ImageDescriptor desc = ImageDescriptor.createFromURL(url); registry.put(IMAGE_ID, desc); } }

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Creating new Perspectives  Extension point: org.eclipse.ui.perspectives  Defines initial layout relative to editor area and contents of menus and toolbar  API allows for whatever you can do in Window > Customize Perspective  See Help for a good explanation in the PDE section to create new perspectives

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Views and Editors  Workbench contains Views and Editors. Create one using the PDE plug-in template wizard.

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Views and Editors Compared Views

Editors

E.g., Outline/Navigator E.g., Java Editor/PDE Arbitrary contents

Arbitrary contents

Arbitrary layout

Arbitrary layout

One per page

Multiple per page

Anywhere on page

At fixed page location

Nothing to save

Can be “dirty”

Have a local toolbar

Use global toolbar

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A Minimal Editor  Step one: declare extension point, specify what file extensions to handle, and class name of editor.

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A Minimal Editor  Step two: Implementation. public class MinimalEditor extends EditorPart { private Label contents; public void createPartControl(Composite parent) { contents = new Label(parent, SWT.NONE); contents.setText("Minimal Editor"); } public void init(IEditorSite site, IEditorInput input) { setSite(site); setInput(input); } public void setFocus() { contents.setFocus(); } } © 2005 IBM

More Elaborate Editors  For form-based editors, such as the PDE plugin.xml editor, use the org.eclipse.ui.forms extension point  For graphical editors, see the Eclipse Graphical Editor Framework (GEF) project at http://eclipse.org/gef  For nested editors, see the PDE wizard that creates a multi-page editor, using the MultiPageEditorPart.  For text editors, see Chapter 15 and 19 of the Eclipse FAQ book © 2005 IBM

Buttons and Menus  Menus and toolbars use ‘Actions’ to define content:

 See the PDE wizard for the ‘Hello World’ plug-in

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Commands  An abstraction of Actions  Do not physically appear in the UI, and they have no code associated with them  Must be associated with an action that performs the work  Key bindings are associated with commands  Example: The ‘Cut’ command is mapped to Ctrl+C. When an editor gets focus, it associates a particular text cut action with that command © 2005 IBM

What is an Eclipse Application?  Could be “headless” with no UI  Could use just runtime (extension registry)  Just SWT and JFace  But Eclipse has a particular technical use of the word “application”. Only one per Eclipse instance; the equivalent of ‘main’

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What is an Eclipse Application?  Sample of plugin.xml for a simple headless application:

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What is an Eclipse Application?  Here is the Java part for this sample: public class HelloWorld implements IPlatformRunnable { public Object run(Object args) { System.out.println("Hello"); return EXIT_OK; } }

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What is an Eclipse Application?  Here is how the sample is executed: eclipse −application acme.hello  The fully qualified ID is the plugin ID + application ID (i.e., “acme” + “.” + “hello”).  Application get to fully control contents of menu, toolbar, views, etc. Much more control than plugins hosted by the Eclipse IDE.  Eclipse Application can have UI or be headless  See also IDEApplication in org.eclipse.ui.ide.

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What is an RCP app?  RCP apps have more control over UI  Workbench is still in charge, but takes “advice” from the RCP application  WorkbenchAdvisor: main advisor; responsible for event loop, application lifecycle, creating other advisors  WorkbenchWindowAdvisor: responsible for lifecycle of a window  ActionBarAdvisor: responsible for filling the menus, tool bars, and status bar © 2005 IBM

Minimal Eclipse RCP App?  Simple workbench advisor that is also the application: public class MinimalRCPApp extends WorkbenchAdvisor implements IPlatformRunnable { createWorkbenchWindowAdvisor(...) {...} getInitialWindowPerspectiveId() {...} run(...) {...} }

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Minimal Eclipse RCP App?  First, tell the configurer what perspective to use: public String getInitialWindowPerspectiveId() { return "org.eclipse.faq.minimalperspective"; }

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Minimal Eclipse RCP App?  Define a workbench window advisor: public WorkbenchWindowAdvisor createWorkbenchWindowAdvisor( IWorkbenchWindowConfigurer configurer) { return new MinimalWindowAdvisor(configurer); } class MinimalWindowAdvisor extends WorkbenchWindowAdvisor { public void preWindowOpen() {…} }

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Minimal Eclipse RCP App?  Then, window advisor defines what to show: public void preWindowOpen() { IWorkbenchWindowConfigurer configurer = getWindowConfigurer(); configurer.setShowCoolBar(false); configurer.setShowFastViewBars(false); configurer.setShowMenuBar(false); configurer.setShowPerspectiveBar(false); configurer.setShowProgressIndicator(false); configurer.setShowStatusLine(false); }

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Minimal Eclipse RCP App?  Finally, get an SWT display, and launch the platform on it, using your workbench advisor: public Object run(Object args) throws Exception { Display d = PlatformUI.createDisplay(); int ret = PlatformUI.createAndRunWorkbench(d, this); if (ret == PlatformUI.RETURN_RESTART) return EXIT_RESTART; return EXIT_OK; }

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Minimal Eclipse RCP App?  The result: no menu bar, no toolbar, no status bar, no views, no editors:

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Customizing the RCP menus  Method implemented by ActionBarAdvisor: public void fillMenuBar(IMenuManager mainMenu) { MenuManager windowMenu = new MenuManager("&Window", IWorkbenchActionConstants.M_WINDOW); mainMenu.add(windowMenu); windowMenu.add(ActionFactory.MAXIMIZE.create(window)); MenuManager helpMenu = new MenuManager("&Help", IWorkbenchActionConstants.M_HELP); mainMenu.add(helpMenu); helpMenu.add(new AboutAction()); }

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Enabling action key bindings  Key bindings are made for free when you use the actionSet extension point in your plugin.xml  When you create actions on the fly, make sure your action has a command ID, and then use: ActionBarAdvisor advisor = ...; IAction action = ...; advisor.register(action);

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Just use SWT and JFace?  FAQ 247 discusses how simple that is  Complete source is offered at http://eclipsefaq.org

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Storing Application Data      

Data is stored in the ‘workspace’ Simplest way is to rely on the –data argument See Platform.getInstanceLocation(); Make sure to lock the workspace location You can choose your own location See IDEApplication for all the subtleties

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Application vs. Product  Application has program logic written in Java  Product is entirely declarative and specifies:  Icons, text, splash screen, etc

 One product, can have multiple applications  Example: Eclipse IDE is one product, but has multiple applications, such as the workbench and custom Ant runners

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Product Distribution       

Zip it up, add a JRE, use an installer Use features and an Update for upgrades Add multiple languages (lots of support here) Use install handlers to do post-installation fixes Add your own splash screen and workbench icon Write your own platform launcher (eclipse.exe) Use art from http://eclipse.org/artwork/main.html

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Customizing RCP Apps  See the plugin_customization.ini file  Example to use curved view header tabs: org.eclipse.ui/SHOW_TRADITIONAL_STYLE_ TABS=false  See Help > Help Contents > Platform Plug-in Developers Guide > Programmer’s Guide > Packaging and Delivering Eclipse-based Products > What is a Product? > Customizing a Product

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How do I create a plug-in?  Plug-in Development Environment (PDE) has special wizards to get you going quickly  Use code templates to create a plug-in with: A toolbar button and a menu option An editor A view (with a tree or a table) A property page A new perspective

 Help > Cheat Sheet… © 2005 IBM

Plugin-Development  Tip: Use the PDE wizards and editors

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Creating an RCP Application

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Running an RCP Application 1. Launch from the project’s context menu:

2. Or simply from the PDE editor:

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Branding an RCP Application  Creating an Eclipse Product is also easy  See File > New > Other... > Product Configuration

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How do I edit a plug-in? Plug-in Manifest editor provides a graphical view on the plug-in XML file. F1 can be used to get Help.

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Extension point creation  Plug-ins can publish extension points  Create them ala “Monkey see, Monkey do”  Alternatively, use PDE manifest editor: Extension Points > Add… Choose an ID and a name Choose a name for your schema Add one or more elements and save

 Generated code ends up in plugin.xml file  Click F1 to get Help © 2005 IBM

How do I create a feature?  A special PDE wizard can create a feature: File > New > Other... > Plug−in Development > Feature Project

 Just add the plug-ins you want to add  Features are the next step up from plug-ins  A product is shipped as a collection of features, each containing one/more plug-ins

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What is the update manager?  Help > Software Updates…  Allows you to find new features on your workstation, network, or the Internet  Manages configurations, allowing installation and deactivation of features  Needs “update sites” to download features

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How to create an update site?  A special PDE wizard: File > New > Other... > Plug−in Development > Update Site Project

 Just add the features you want to add  Generates site.xml  Editor has a special “Build All” button

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Plug-in, Feature, Update Site  Update site has one or more features  Features have one or more plug-ins  Plug-ins provide icons, plugin.xml and Java implementation  Supports versioning

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References

 http://eclipse.org  http://dev.eclipse.org/viewcvs/index.cgi/~che ui-home/rcp  http://eclipsefaq.org  http://eclipse.techforge.com

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