Element Factories
Identifier: 
org.eclipse.ui.elementFactories
Description: 
This extension point is used to add element factories 
to the workbench.  An element factory is used to 
recreate IAdaptable objects which are 
persisted during workbench shutdown. 
As an example, the element factory is used to 
persist editor input.  The input for an 
editor must implement 
org.eclipse.ui.EditorInput.  
The life cycle of an IEditorInput within 
an editor has a number of phases. 
- 
The initial input for an editor is passed in during 
editor creation. 
- 
On shutdown the workbench state is captured.  
In this process the workbench will create a memento 
for each open editor and its input.  The input is 
saved as a two part memento containing a factory ID 
and any primitive data required to recreate the 
element on startup.  For more information see 
the documentation on 
org.eclipse.ui.IPersistableElement. 
- 
On startup the workbench state is read and the 
editors from the previous session are recreated.  
In this process the workbench will recreate the input 
element for each open editor.  To do this it will 
map the original factory ID for the input element 
to a concrete factory class defined in the registry.  
If a mapping exists, and the factory class is valid, 
an instance of the factory class is created.  Then 
the workbench asks the factory to recreate the original 
element from the remaining primitive data within the 
memento.  The resulting IAdaptable is cast
to an IEditorInput and passed to the 
new editor. 
Configuration Markup:
<!ELEMENT extension (factory*)>
<!ATTLIST extension
point CDATA #REQUIRED
id    CDATA #IMPLIED
name  CDATA #IMPLIED>
- point - a fully qualified identifier of the target extension point
- id - an optional identifier of the extension instance
- name - an optional name of the extension instance
<!ELEMENT factory EMPTY>
<!ATTLIST factory
id    CDATA #REQUIRED
class CDATA #REQUIRED>
- id - a unique name that will be used to identify this factory.
- class - a fully qualified name of a class that implements 
org.eclipse.ui.IElementFactory
Examples: 
The following is an example of an element factory extension: 
   <extension 
        point = "org.eclipse.ui.elementFactories"> 
        <factory 
           id ="com.xyz.ElementFactory" 
           class="com.xyz.ElementFactory"> 
        </factory> 
    </extension> 
API Information: 
The value of the class attribute must 
be a fully qualified name of a class that implements 
org.eclipse.ui.IElementFactory. An instance 
of this class must create an IAdaptable 
object from a workbench memento.
Supplied Implementation: 
The workbench provides an IResource factory.  
Additional factories should be added to recreate other 
IAdaptable types commonly found in other 
object models, such as the Java Model.
Copyright (c) 2002, 2005 IBM Corporation and others.
All rights reserved. This program and the accompanying materials are made
available under the terms of the Eclipse Public License v1.0 which accompanies
this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html