Decorators

Identifier:
org.eclipse.ui.decorators

Since:
2.0

Description:
This extension point is used to add decorators to views that subscribe to a decorator manager. As of 2.1 there is the concept of a lightweight decorator that will handle the image management for the decorator. It is also possible to declare a lightweight decorator that simply overlays an icon when enabled that requires no implementation from the plug-in.

An action's enablement and/or visibility can be defined using the elements enablement and visibility respectively, if the extension point supports it. These two elements contain a boolean expression that is evaluated to determine the enablement and/or visibility.

The syntax is the same for the enablement and visibility elements. Both contain only one boolean expression sub-element. In the simplest case, this will be an objectClass, objectState, pluginState, or systemProperty element. In the more complex case, the and, or, and not elements can be combined to form a boolean expression. Both the and, and or elements must contain 2 sub-elements. The not element must contain only 1 sub-element.

Configuration Markup:

<!ELEMENT extension (decorator*)>

<!ATTLIST extension

point CDATA #REQUIRED

id    CDATA #IMPLIED

name  CDATA #IMPLIED>


<!ELEMENT decorator (description? , enablement?)>

<!ATTLIST decorator

id          CDATA #REQUIRED

label       CDATA #REQUIRED

class       CDATA #IMPLIED

objectClass CDATA #IMPLIED

adaptable   (true | false)

state       (true | false)

lightweight (true|false)

icon        CDATA #IMPLIED

location    (TOP_LEFT|TOP_RIGHT|BOTTOM_LEFT|BOTTOM_RIGHT|UNDERLAY|REPLACE) >


<!ELEMENT description (#PCDATA)>

an optional subelement whose body should contain text providing a short description of the decorator. This will be shown in the Decorators preference page so it is recommended that this is included. Default value is an empty String.



<!ELEMENT enablement (and | or | not | objectClass | objectState | pluginState | systemProperty)>

This element is used to define the enablement for the extension.



<!ELEMENT visibility (and | or | not | objectClass | objectState | pluginState | systemProperty)>

This element is used to define the visibility for the extension.



<!ELEMENT and (and | or | not | objectClass | objectState | pluginState | systemProperty)>

This element represent a boolean AND operation on the result of evaluating its two sub-element expressions.



<!ELEMENT or (and | or | not | objectClass | objectState | pluginState | systemProperty)>

This element represent a boolean OR operation on the result of evaluating its two sub-element expressions.



<!ELEMENT not (and | or | not | objectClass | objectState | pluginState | systemProperty)>

This element represent a boolean NOT operation on the result of evaluating its sub-element expressions.



<!ELEMENT objectClass EMPTY>

<!ATTLIST objectClass

name CDATA #REQUIRED>

This element is used to evaluate the class or interface of each object in the current selection. If each object in the selection implements the specified class or interface, the expression is evaluated as true.



<!ELEMENT objectState EMPTY>

<!ATTLIST objectState

name  CDATA #REQUIRED

value CDATA #REQUIRED>

This element is used to evaluate the attribute state of each object in the current selection. If each object in the selection has the specified attribute state, the expression is evaluated as true. To evaluate this type of expression, each object in the selection must implement, or adapt to, org.eclipse.ui.IActionFilter interface.



<!ELEMENT pluginState EMPTY>

<!ATTLIST pluginState

id    CDATA #REQUIRED

value (installed|activated) "installed">

This element is used to evaluate the state of a plug-in. The state of the plug-in may be one of the following: installed (equivalent to the OSGi concept of "resolved") or activated (equivalent to the OSGi concept of "active").



<!ELEMENT systemProperty EMPTY>

<!ATTLIST systemProperty

name  CDATA #REQUIRED

value CDATA #REQUIRED>

This element is used to evaluate the state of some system property. The property value is retrieved from the java.lang.System.



Examples:
The following are example of decorators:

A full decorator. The plug-in developer must handle their own image support.


 <extension point="org.eclipse.ui.decorators"> 
        <decorator
            id="com.xyz.decorator" 
            label="XYZ Decorator" 
            state="true" 
            class="com.xyz.DecoratorContributor">
            <enablement>
                <objectClass name="org.eclipse.core.resources.IResource"/> 
            </enablement>
        </decorator>
    </extension> 

A lightweight decorator. There is a concrete class but as it is an ILightweightLabelDecorator it only needs to supply text and an ImageDescriptor and therefore needs no resource handling.


 <extension point="org.eclipse.ui.decorators"> 
        <decorator
            id="com.xyz.lightweight.decorator" 
            label="XYZ Lightweight Decorator"                 
            state="false" 
            class="com.xyz.LightweightDecoratorContributor" 
            lightweight="true" >
            <enablement>
                <objectClass name="org.eclipse.core.resources.IResource"/> 
            </enablement>
        </decorator>
    </extension> 

A declarative lightweight decorator. There is no concrete class so it supplies an icon and a quadrant to apply that icon.


 <extension point="org.eclipse.ui.decorators"> 
        <decorator
            id="com.xyz.lightweight.declarative.decorator" 
            label="XYZ Lightweight Declarative Decorator" 
            state="false" 
            lightweight="true" 
            icon="icons/full/declarative.png"
            location="TOP_LEFT"> 
            <enablement>
                <objectClass name="org.eclipse.core.resources.IResource"/> 
            </enablement>
        </decorator>
    </extension>

API Information:
The value of the class attribute must be the fully qualified name of a class that implements org.eclipse.jface.viewers.ILabelDecorator (if lightweight is false) or org.eclipse.jface.viewers.ILightweightLabelDecorator. This class is loaded as late as possible to avoid loading the entire plug-in before it is really needed. Declarative decorators do not entail any plug-in activation and should be used whenever possible. Non-lightweight decorators will eventually be deprecated.

Supplied Implementation:
Plug-ins may use this extension point to add new decorators to be applied to views that use the decorator manager as their label decorator. To use the decorator manager, use the result of IViewPart.getDecoratorManager() as the decorator for an instance of DecoratingLabelProvider. This is currently in use by the Resource Navigator.


Copyright (c) 2002, 2014 IBM Corporation and others.
This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which accompanies this distribution, and is available at https://www.eclipse.org/legal/epl-v20.html/ SPDX-License-Identifier: EPL-2.0