Eclipse

1
Eclipse

• Paolo Gasti

2
The Problem

• There is the need for a new development
  environment
• It has to help software designers and
  implementers to do their jobs faster and easier
• There are so many approaches to software
  development that no tool can be the solution
• We need to fill the blank left by tools such as
  Emacs

3
What is Eclipse?
Eclipse is more than a Java IDE

• Eclipse is a kind of universal tool platform
  an open extensible IDE for anything and nothing
  in particular.
• eclipse.org

In many ways Eclipse is the Emacs for the 21st
century. Martin Fowler
4
The Way to Eclipse
2003
1999
2000
2001
2002
1998
1997
VisualAge/Java
VisualAge Micro edition
Eclipse
March v. 2.1
Oct v. 1.0
June v. 2.0
June Tech Preview
Nov Open Source announcement
5
Design Goals

• Provide an open platform for the construction of
  tools for application development
• Support an unrestricted set of tool providers
• Support tools to manipulate arbitrary content
  types (language neutral)
• Seamless integration of tools within and across
  different content types and tool providers
• Availability on a wide range of platforms

6
Plug-in Architecture Goals

• Easy to develop
• Java Development Tools Plug-in development
  environment
• Scale-up to hundreds of installed plug-ins
• It tries to reduce start-up time
• Out-of-the-shelf Eclipse consists of 80 plug-ins
• Lazy loading
• Easy to discover, install, and update
• install/update support
• Easy to manage an installation
• managed configurations

7
Why Open Source

• Many partners can contribute during all the life
  cycle of a tool
• It provides less dependency on a single vendor
• Every partner can implement its own product
  without the need to stipulate any contract with
  IBM
• The community can
• provide feedback to the developers
• submit patches
• answering users questions

8
Implications

• Vendors can concentrate on their own special area
  of expertise providing higher value
• Improved integration of tools from multiple
  vendors
• The interface can be customized to fit any
  function, format or style
• Plug-ins can be free or commercial
• A flourishing business gravitates around Eclipse
  (WebSphere etc)

9
Eclipse Architecture

• Plug-in, the smallest unit of Eclipse function
• Eclipse is a platform with a small runtime Kernel
  and several layers of plug-in built on it
• Everybody can be a tool smith
• SWT (Standard Widget Toolkit) offers significant
  advantages over AWT and Swing

Platform
Extensible IDE
Plug-ins
IDE
Plug-ins
Runtime
10
Eclipse Architecture

PDE Core, PDE Build, PDE UI
SDK
Compiler, Refactoring, JDT UI, JDT Debug,
Resources, Team, Debug, Help, Update, SWT, UI,
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Eclipse Architecture
Another Tool
Eclipse Platform
Help
Workbench
Java Development Toolkit (JDT)
JFace
Team
SWT
Your Tool
Debug
Plug-in Development Environment (PDE)
Workspace
Update
Their Tool
Platform Runtime
Eclipse Project
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Eclipse Platform Start Up

• Eclipse Platform Runtime handles start up
• Discovers plug-ins installed on disk
• Matches up extensions with extension points
• Builds global plug-in registry
• Caches registry on disk for next time

13
Eclipse Platform

• The Platform is divided into components
• The standard components, provided with the
  installation file freely downloadable from
  eclipse.org, are
• Ant Universal Compare
• Core Release Engineering
• Platform CVS Integration Debug framework
• Platform help system Text editor framework
• Support for Platform scripting Platform user
  interface
• Integrated search facility WebDAV integration
  
• SWT (Standard Widget Toolkit) Generic Team
  support
• Dynamic Update/Install Service

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Plug-in Architecture

• Extension point - named entity for collecting
  contributions
• Extension - a contribution
• Each plug-in
• Contributes to 1 or more extension points
• Optionally declares new extension points
  programmers can extend good plug-ins to fit their
  needs
• Depends on a set of other plug-ins
• Contains Java code libraries and other files
• Details spelled out in the plug-in manifest
• Manifest declares contributions
• Code implements contributions and provides API

15
Extension Points Principles

• Let others contribute to your contributions
• Lazy loading rule load extensions only when they
  are about to be called
• Contributions do not
• override existing behavior
• remove or replace existing component
• harm existing or future contributions

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Extension configuration in XML
ltplugin idorg.eclipse.uigt
ltextension-point namePrefs" idpreferencepages
schema"schema/prefs.exsd"/gt
lt/plugingt ltplugin idmyPlugingt
ltextension point"org.eclipse.ui.preferencepages"gt
ltpage idcom.example.myprefpage"
icon"icons/image.gif" titleMy title"
classcom.example.mywizard"gt lt/pagegt
lt/extensiongt lt/plugingt
Extension point definition
Extension contribution
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Plug-in Manifest
ltplugin id com.example.tool
version 2.1.0 name Example Plug-in
Tool" class "com.example.tool.ToolPlugin"gt
ltrequiresgt ltimport plugin
"org.eclipse.core.resources version2.0.0/gt
ltimport plugin "org.eclipse.ui version
2.0.1/gt lt/requiresgt ltruntimegt
ltlibrary name tool.jar"/gt lt/runtimegt
ltextension point "org.eclipse.ui.preferenc
epages"gt ltpage id "com.example.tool.prefere
nces" icon "icons/knob.gif"
title Tool Knobs" class
"com.example.tool.ToolPreferenceWizard/gt
lt/extensiongt ltextension-point name
Frob Providers id "com.example.tool.frob
Provider"/gt lt/plugingt
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Contribution architecture
My Plug-in
ImageViewer Plugin
extension-pointimageFilters
contributes
extension
implements
interface IImageFilter
class GreyFilter
calls

• Declares extension point ltextension-point
  idimageFilters/gt
• Declares interface interface IImageFilter
  Image filter(Image image)

• Contributes extension ltextension
  point.imageFilters/gt classGreyFilterlt/e
  xtensiongt
• Implements interface class GreyFilter
  implements IImageFilter

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Contribution architecture
My Plug-in
ImageViewer Plugin
contributes
extension-pointimageFilters
extension
implements
interface IImageFilter
class GreyFilter
calls
Instantiated via reflection

• Declares extension point ltextension-point
  idimageFilters/gt
• Declares interface interface IImageFilter
  Image filter(Image image)

• Contributes extension ltextension
  point.imageFilters/gt classGreyFilterlt/e
  xtensiongt
• Implements interface class GreyFilter
  implements IImageFilter

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Plug-in Activation

• Each plug-in gets its own Java class loader and
  has its own class path
• Delegates class load requests to required
  plug-ins
• Contributions processed without plug-in
  activation
• Example Menu constructed from manifest info for
  contributed items
• Plug-ins are activated only as needed
• When a class is loaded by the class loader
• Scalable for large base of installed plug-ins

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More than a Java IDEEclipse vs. NetBeans

• Source configuration mgt.
• Perforce
• Microsoft VSS Plug-in
• Clearcase
• Stellation
• Web development
• Sysdeo - Eclipse Tomcat Launcher
• WebLogic manager
• Several Struts
• Spindle for Tapestry
• Testing / Performance
• Resin Plug-in
• MockCreator
• Solex
• Hyades

• Languages
• C
• C/C
• Python
• Cobol
• Php
• Several UML
• Programming Tools
• ANTLR Parser Generator
• Graphical Editing Framework (GEF)
• AspectJ tools
• Modeling (EMF)
• Several DB tools
• Jalopy Java Source Code Formatter
• Japple RAD
• Jasper report designer
• Lomboz

http//www.eclipse.org/community/plugins.html
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The UML 2 plug-ins

• There are several UML 2 compliant plug-ins
• Most of them provide support for
• Reverse-engineering of source code (often also
  from binaries)
• Code generation
• Code Synchronization
• Code analysis
• Documentation generation
• Automatic diagram altering after code altering

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Slime UML 2 plug-in

• Guides the team through all the development
  process
• It is very light-weight only 1 MB

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Refactoring Support

• Refactoring is changing the structure of a
  program without changing its functionality
• There are many reasons to do refactoring
• The team of a project disappears and you need to
  add/improve the functionality of its (quite
  obscure) code
• A new requirement is introduced because of a
  design mistake or an iterative approach (such as
  XP)
• Once familiar with this tool, a programmer can
  generate code in the first place, then use it to
  conform its code to some standards (such as the
  use of getter/setter methods)

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Refactoring Support

• Eclipse provides three types of Refactoring
• Physical organization and renaming
• Logical organization at the class level
• Change the code within a class

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Physical organization and renaming

• Avoid the need to edit many files to update
  import and package statements
• Automatically checks the context, not only the
  names
• Allows to automatically
• Rename fields
• Rename variables
• Rename classes and interfaces
• Move packages and classes

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Logical organization at the class level

• While not as useful as the other kind of
  refactorings, it allows to automatically
• Turn anonymous classes into nested classes
• Turn nested classes into top-level classes
• Create interfaces from concrete classes
• Move methods or fields from a class to a subclass
  or superclass

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Change the code within a class

• Allows you to automatically
• Turn local variables into class fields
• Turn selected code in a method into a separate
  method
• Generate getter and setter methods for fields
• Change method signature (doesnt fit exactly
  here)

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Refactoring Support

• The power of Eclipses refactoring capability is
  to allow an user to do a safe refactoring with
  some mouse clicks

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Eclipses Cons

• Windows-centric (ActiveX, OLE)
• Slow and often unstable under Unix
• Forces developers to use its own directory
  structure
• Sun does not like it exists, having its own
  NetBeans (but Eclipse is supported by IBM)

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Case of Study the JavaCard Plug-in

• It offers the complete class library of the
  JavaCard platform
• Allows developers to simulate IBMs smart card
  hardware
• Offers an advanced debugger
• Lets Eclipse connect to real smart cards
• Offer complex functionalities

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Case of Study the JavaCard Plug-in

• Offers concrete advantages against the
  stand-alone version
• The Java Editor provided with Eclipse is much
  better than the editor provided with JavaCard
• Allows the developer to edit and test the code
  with the same interface
• Can be used together with other tools such us an
  UML 2 plug-in
• Shows the power of the Eclipse platform when
  developing highly specialized software

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Summary

• All functionality is provided by plug-ins and
  fragments
• Includes all aspects of Eclipse Platform itself
• Contributions are made via extension points
• Extensions are created lazily
• Plug-ins are packaged into separately installable
  features
• Downloadable

34
Summary

• Everybody can contribute plug-ins
• Every programmer can be a tool smith
• Creating opportunities for further extension
  makes it possible for the tool smith to benefit
  from the work of others
• The same environment can be used to develop
  applications and to develop tools for itself

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References

• Refactoring For Everyone by IBM
  (http//www-106.ibm.com/developerworks/opensource/
  library/os-ecref/)
• Eclipse Platform Technical Overview eclipse.org
• The Mathaino Project - Department of Computing
  Science, University of Alberta
• Eclipse Platform on-line help
• Omondo whitepaper www.omondo.com
• Eclipse.org plug-ins documentation -
  http//www.eclipse.org/community/plugins.html
• OOPSLA 2003 documentation www.oopsla.org