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Redistribution and other use of this material requires written permission from The RCP Company.

ITU - MDD - Eclipse Plug-ins

This presentation shows how Eclipse plug-ins are developed. It has two purposes:Introduce you to the architecture and techniques of a major component based applicationIntroduce you to basic Eclipse plug-in development – this will hopefully ease the needed programming in the rest of the course

This presentation is developed for MDD 2010 course at ITU, Denmark.

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Equipment and Groups

Today's lecture will include a bit of Java development!

So…

You need your laptop

You need the following installed and tested – please – on your laptop Eclipse 3.6 Modelling Edition Java SDK 6

You need to be in a group of people (3-4) with some knowledge of Eclipse IDE as a development platform Java development User interface development – if possible

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Agenda

Eclipse Architecture The basic plug-in What is a plug-in? Standard Widget Toolkit – SWT

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Agenda

Eclipse Architecture What are the drivers for the Eclipse architecture What are the requirements for the architecture

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Some Numbers on Eclipse

The Eclipse Modeling Tools 1099 plug-ins 229 features

All Eclipse Projects >45 projects in the Galileo release train 29 MLoC >500 active committers >25 countries >140 locations

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Project Activity

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So…

We need an architecture that supports distributed development over a large number of autonomous development groups

We need a component concept where components are loosely coupled and can be started (and stopped) independently

We need a way to describe external interfaces of components and dependencies between components

We need a way to only start the components as they are needed – also known as late activation

We need all this to work over multiple generations of components

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Eclipse Architecture

Goals for the Eclipse architecture Be able to host any number of 3rd party applications Scalability in terms of size and complexity of hosted applications Alignment with native UI look-n-feel

Flexible architecture, structured around Plug-ins – the basic unit of functionality Extension points – the defined interfaces between plug-ins

This architecture allows for Implementation of 3rd party applications on top of the basic platform

(Eclipse RCP) Additional tools to be integrated in the platform Integrated tools to be further extended

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EclipsePlatform

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The Basic RCP Components

In the Eclipse, everything is a plug-in including the run-time platform itself It is a small kernel that represents the base of the platform Built on top of OSGi

All subsystems built on the run-time platform follows the rules of plug-ins: They are plug-ins themselves

RCP includes: Component Management Resources Management Preferences Workbench (include SWT and JFace)

RCP does not include functionality that are not commonly needed: Update Help This can be included from the Eclipse platform

Eclipse RCP

Run-time/OSGi

SWT

JFace

WorkbenchP

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Jobs

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Organizing the Platform

The software of an Eclipse system is based on the following terms: Plug-ins – a plug-in is the basic unit of software Fragments – a fragment is an add-on to an existing plug-in with

additional functionality Features – a feature is a number of plug-ins that is distributed and

updated as a whole Applications – an application is a Java class that implements a specific

interface and is declared as such in the plug-in Products – a product is a set of features or plug-ins along with the

appropriate branding

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Extension Points

Describe additional functionality that could be integrated with the platform External tools extend the platform to bring specific functionality Java Development Tooling (JDT) and Plug-in Development Environment (PDE)

are external tools integrated with the platform Extension points are used to

Add an implementation for a generic feature Extend the workbench Extend common object factory

Advantages: Allows for late load and startup of plug-ins Provides a common “registry” for most extensions like views, perspectives,

commands, etc Disadvantages:

Makes it harder to understand flow of control ID Hell!

Extension points may have corresponding API interface Describes what should be provided in the extension

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Eclipse RCP

Run-time/OSGi

SWT

JFace

Workbench

Pre

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Jobs

ICU

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The Role of Run-Time/OSGi

Dynamic module system for Java Solves many of the problems of big applications

Late activation of code Multiple versions of the same library

Eclipse is the reference implementation!

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Eclipse RCP

Run-time/OSGi

SWT

JFace

Workbench

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Jobs

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Workbench

Represents the desktop development environment

It contains set of tools for resource management

It provides common way of navigating through the resources

Multiple workbenches can be opened at the same time in individual windows

PR0005 - 2008-04-10

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Eclipse Development Model

Yearly releases Always released around 27. June – just before the start of the

Canadian holidays Many diverse and highly independent development teams

More than 25 countries involved in Eclipse 3.5 Galileo Many milestones and release candidates

5 monthly milestones (August to February) 4 release candidates (May and early June)

Still room for integration of other mayor projects Many projects are released with other release schedules

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Agenda

The Basic Plug-In How to build a basic Eclipse plug-in and get it included in Eclipse IDE

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Show and Tell

You will be shown how to create a new plug-in with A new perspective A new view A new command for the view

The new plug-in will be included in Eclipse

If you need to do this again, have a look at the two tutorials listed in the last slides

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Basic Eclipse UI Information Model

Workbench Window

Workbench Page

Editors Views

PerspectiveTop-level menu

Top-level toolbar

Status line

Perspective switcher

Drop-down menuLocal toolbar

Workbench

0..n

1..n

0..n0..n

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Lab Exercise

Create 4 views altogether Add the views to the perspective

The way to position views in a perspective have not be discussed in details, but…

Add the Help→About command to one of the views

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Agenda

What is a plug-in? What makes up a plug-in? How are they managed and developed?

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What is an Eclipse Plug-in

A plug-in is the smallest functionality that is managed in the Eclipse platform

Plug-ins are described via a number of configuration files Plug-ins have different forms under development and runtime Plug-ins are sometimes deployed individually

If you need update support, plug-ins must always be deployed as parts of a feature

A fragment has the same structure as a plug-in with very few changes

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Runtime Files of a Plug-in

OSGi files META-INF/MANIFEST.MF – description of OSGi bundle .options – options for this specific plug-in

General plug-in files plugin.xml and fragment.xml – description of extension points and

extensions of a plug-in plugin.properties and fragment.properties – localized strings for

the previous files

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Development Time Files of a Plug-in

.project – basic description of Eclipse project .classpath – the Java class path for a Java Eclipse project (and thus also

a PDE project) .settings – preference store for project level preferences – includes all

property settings for the project *.product – product declaration files build.properties – build information for Ant with content of the

resulting jar files for the project *.exsd – extension point declaration files

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MANIFEST.MF File

The OSGi manifest file describes the identify of the plug-in and the dependencies on other plug-ins

Manifest files are very seldom edited directly!

Manifest-Version: 1.0Bundle-ManifestVersion: 2Bundle-Name: %pluginNameBundle-SymbolicName: com.rcpcompany.training.cm33.core; singleton:=trueBundle-Version: 2.1.0Bundle-ClassPath: .Bundle-Vendor: %providerNameBundle-Localization: pluginBundle-RequiredExecutionEnvironment: J2SE-1.5Export-Package: com.rcpcompany.training.cm33.core, com.rcpcompany.training.cm33.core.utilRequire-Bundle: org.eclipse.core.runtime, org.eclipse.emf.ecore;visibility:=reexportBundle-ActivationPolicy: lazy

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plugin.xml File

plugin.xml describes extension points and extensions<extension point="org.eclipse.ui.commands">

<commandid="com.rcpcompany.demo.menu33.commands.HelloWorld"name=”&amp;Sample Action” />

</extension><extension point="org.eclipse.ui.commandImages">

<imagecommandId="com.rcpcompany.demo.menu33.commands.HelloWorld"icon="icons/sample.gif” />

</extension><extension point="org.eclipse.ui.handlers">

<handlerclass="demo.actions.SampleHandler"commandId="com.rcpcompany.demo.menu33.commands.HelloWorld” />

</extension><extension point="org.eclipse.ui.menus">

<menuContribution locationURI="menu:org.eclipse.ui.main.menu"><menu

id="sampleMenu"label="Sample Menu"mnemonic="M">

<commandcommandId="com.rcpcompany.demo.menu33.commands.HelloWorld"id="com.rcpcompany.demo.menu33.commands.HelloWorld.mc.sampleMenu” />

</menu></menuContribution>

</extension>

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Plug-in Editor

Double-click on the plugin.xml or MANIFEST.MF opens the editor Almost all plug-in details can be changed in the editor Overview page displays basic plug-in information

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Dependencies Page

Displays dependant plug-ins Created by tools when the plug-in type is chosen New dependences can be added

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Runtime Page

Displays runtime information such as plug-in classpath Populated by the tools based on inputs from wizards Additional libraries can be added to the classpath

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Extensions Page

Displays plug-in extensions Created by the tool based on the plug-in type Extensions can be added

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Extension Points Page

Displays plug-in extension points This example is taken from the org.eclipse.ui plug-in

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Build and build.properties Pages

Interface to the build.properties file specifies which .jar files to generate

Also describes which non-Java files that are part of the generated .jar file

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Agenda

The Standard Widget Toolkit - SWT How to develop the UI parts of an Eclipse plug-.in

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Eclipse User Interface Layers

4 Layers: The Eclipse Workbench

Overall look-n-feel JFace

Architecture-independent models SWT

Platform independent API yet rather close to the metal Native widgets

Platform dependent: Windows, Linux, Mac, Unix The “Eclipse User Interface Guidelines” governs the look-n-feel of the

workbench and JFace Consequently (nearly) all Eclipse RCP based applications look the

same! Use the SWT Bible “The Definitive Guide to SWT and JFace” by Robert

Harris and Rob Warner

Eclipse RCP

Run-time/OSGi

SWT

JFace

Workbench

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Jobs

ICU

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SWT and the Native Widgets

SWT is short for ”The Standard Widget Toolkit” SWT is a sub-project of the Eclipse project SWT has a common API on all target platforms – the implementation is

different Base plug-in org.eclipse.swt contains only MANIFEST.MF plus some

configuration files A set of platform specific fragments implements all of SWT – org.eclipse.swt.win32.win32.x86 for 32-bit Windows on x86 (not Vista look-n-feel)

SWT is a thin layer on top of the native widgets Windows Mac Motif GTK

SWT can easily be used stand-alone

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SWT on Different Platforms

PR0000 - Using Eclipse RCP in your Organization - 2007-09-04

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Extended BrandingHere IBM Lotus Notes version 8

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Working with SWT

SWT API is not as regular as Swing The SWT site contains a large repository of “SWT Snippets” that

demonstrates most of the abilities of SWT To find leaks with graphical resources use sleak It is possible to integrate SWT and Swing to a very large degree

Though expect problems with shortcuts and focus management

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SWT Widgets

Basic Button, Combo, Composite, Group, Label, Link, List, Menu, ProgressBar, Shell, Slider, Scale, Spinner, TabFolder, Table, Text, ToolBar, and Tree

Advanced Browser, Canvas, CBanner, CCombo, CLabel, CoolBar, CTabFolder, DateTime, ExpandBar, GLCanvas, Sash, SashForm, ScrolledComposite, StyledText, SWT_AWT, TableCursor, and Tray

Other Sources – e.g. Nebula, Sourceforge.net FormattedText, Gallery, Grid, and many more

The C... versions of Label, Combo and TabFolder are emulated and should normally be avoided if possible

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SWT Widgets

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The Basic Widget Hierarchy

Widget

Control Menu Item

Button Label Composite List MenuItem TableItem TabItem

Canvas Combo Form OleSiteClient Table, …

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Using SWT Widgets

Common constructor form – e.g. new Text(parent, SWT.PASSWORD) The parent The style argument specifies the basic sub-function of the widget

Use Text controls for data values event when read-only, as this makes it possible to select and copy the value

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Using SWT Styles

Second argument of all widget constructions – e.g. new Text(parent, SWT.PASSWORD)

The most use styles are SWT.NONE – no style needed SWT.LEAD, SWT.CENTER, and SWT.TRAIL - the alignment of text in

labels, menus and buttons SWT.ARROW, SWT.CHECK, SWT.PUSH, SWT.RADIO, and SWT.TOGGLE - the

sub-type of a button SWT.PASSWORD - Text is used for password entry SWT.V_SCROLL, SWT.H_SCROLL, and SWT.NO_SCROLL – Table or Tree

has vertical, horizontal or no scroll bar (3.4)

Some special considerations regarding styles Some style arguments cannot be changed once specified in the

constructor (e.g. SWT.CHECK for a Button), whereas others can (e.g. SWT.LEAD for Label)

Some style arguments have different meaning for different widgets –e.g. SWT.MULTI for Table and Text

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SWT Layout Managers

The positioning and sizing of controls in a Composite (and subclasses) is performed using layout managers

SWT includes a rather complete set of standard layout managers FillLayout and RowLayout: layout is a single row or column GridLayout: layout in a grid with size constrains FormLayout: layout in canvas with size and edge-to-edge constrains Most GUI designer can handle these

A new layout manager can be created fairly easily created computeSize: computes the “natural” size of the Composite layout: lays out the controls of the Composite

public abstract class Layout {protected abstract Point computeSize(Composite composite, int wHint, int hHint, boolean flushCache);protected abstract void layout(Composite composite, boolean flushCache);

}

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Using the Grid Layout (GridLayout)

Grid Layout is the most used layout manager in Eclipse It works by adding the child widgets to the cells in a grid

Widgets are added in sequence When using a Grid Layout, the parent uses the GridLayout and all

children use GridDatafinal Composite composite = new Composite(parent, SWT.NONE);final GridLayout gridLayout = new GridLayout(3, false);composite.setLayout(gridLayout);

label = new Label(composite, SWT.NONE);label.setText("Label");

text = new Text(composite, SWT.BORDER);text.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false, 2, 1));// …

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Using the Grid Data (GridData)

GridData specifies how a child widget is laid out in the parent grid A GridData holds the following primary information

Grab Excess Space (horizontal and vertical) – describes whether the grid column or row should expand to grad any excess space (defaults to no grab)

Span (horizontal and vertical) – describes the number of cells the widget should span (defaults to 1,1)

Alignment (horizontal and vertical) – placement of widget within the cells – one of SWT.BEGINNING, SWT.CENTER, SWT.END or SWT.FILL (defaults to BEGINNING, BEGINNING)

A GridData also contains information about indentation, minimum size and size hints Don’t use the two-argument constructor!

1,1 2,12,2

C,C F,C

E,E

Horizontal grabNo grab

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SWT Events

SWT events and listeners exist in two versions: A simple very light-weight version

One event format and listener interface A type-safe version

Multiple event formats and listener interfaces tailored to the specific use

The difference is illustrated in the following example

filter.addListener(SWT.KeyDown, new Listener() {public void handleEvent(Event event) {

if (event.type == SWT.KeyDown) {//...

}}

});

filter.addKeyListener(new KeyAdapter() {@Overridepublic void keyPressed(KeyEvent e) {

//...}

});

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SWT Events

Key KeyDown, KeyUp, HardKeyDown, HardKeyUp

Mouse MouseDown, MouseUp, MouseMove, MouseEnter, MouseExit, MouseDoubleClick, MouseHover, MouseWheel

Control Paint, Move, Resize, Dispose

Selection Selection, DefaultSelection

Focus FocusIn, FocusOut

Tree and Table Expand, Collapse, EraseItem, MeasureItem, PaintItem

Shell Iconify, Deiconify, Close, Activate, Deactivate

Menu Show, Hide, Arm, MenuDetect

Basic Controls Modify, Verify, SetData, Settings

Drag-n-Drop DragDetect

Misc Help

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Lab Exercise

Create a view with the following look using simple SWT controls GridLayout, GridData Label, Text, Button …addSelectionListener(…)

Another extra lab for the fast ones: add “stuff” to the lab to only allow “a” and “b” in the text field and to only allow more “a” than “b”! Use a Verify listener

public class View extends ViewPart {public void createPartControl(Composite parent) {

Composite top = new Composite(parent, SWT.NONE);// Add something here…

}

public void setFocus() {}

}

GridLayout with 2 columns

Label TextFILL aligned + grab

Buttonspans two columns, RIGHT alignedSelectionListener that prints current text of Text control

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More Information (Basic Plug-in)

“Eclipse Plugin Development Tutorial” http://www.eclipsepluginsite.com/

“Eclipse Plugin Development Tutorial” http://www.vogella.de/articles/EclipsePlugIn/article.html

Eclipse Resources http://www.eclipse.org/resources/

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More Information (SWT)

“Eclipse User Interface Guidelines: Version 2.1” http://www.eclipse.org/resources/resource.php?id=162

The Look-n-Feel guidelines for Eclipse – heavily influenced by the corresponding Microsoft Windows Look-n-Feel guidelines

SWT home http://www.eclipse.org/swt/

SWT versus Swing http://www.developer.com/java/other/article.php/2179061

“Using SwingRCP (instead of SWT) in RCP” http://www.eclipsezone.com/eclipse/forums/t104467.rhtml

A discussion of different ways to integrate Eclipse RCP and Swing “The Definitive Guide to SWT and JFace” by Robert Harris and Rob Warner

(ISBN: 978-1590593257) As it says – “The Definitive Guide…” – and needed due to the pure

javadoc of SWT “SWT Snippet” Repository

http://www.eclipse.org/swt/snippets/ A large repository of sample code for most uses of SWT!