org.eclipse.ui.menus
Commands can be implemented using
org.eclipse.ui.handlers
and bound to keys using
org.eclipse.ui.bindings.
With the
org.eclipse.ui.menus
extension point they can be placed in the main menu, view dropdown menus, context
menus. They can also be added to the main toolbar, view toolbars, and various
trim locations.
Contribution location
The older action contribution points use the concept of
menu and toolbar paths
to place menu items and tool items. The org.eclipse.ui.menus
extension point requires the id of a menu, toolbar, or trim area and an insertion
point. This is the locationURI of a <menuContribution/> element.
Some examples of locationURIs:
- menu:org.eclipse.ui.main.menu?after=window - insert this contribution in the
main menu after the Window menu.
- menu:file?after=additions - insert this contribution in the File menu
after the additions group. Equivalent to the old menubarPath="file/additions".
- menu:org.eclipse.ui.views.ContentOutline?after=additions - insert this
contribution in the Content Outline view dropdown menu after the additions group.
- toolbar:org.eclipse.ui.views.ContentOutline?after=additions - insert this
contribution in the Content Outline view toolbar, after the additions group.
- popup:org.eclipse.ui.examples.propertysheet.outline?after=additions - insert
this contribution in the Property Sheet outline page context menu after
the additions group.
A word about popup: locationURIs. In popup:id
, the id refers to
the id that comes from registering the context menu when the registerContextMenu(*)
method is called. If an no id is specified in the call, it defaults to the id of
the view or editor registering the context menu.
The workbench defines all of its group slot names in the classes
IWorkbenchActionConstants
and
IIDEActionConstants
.
These ids, like the file example above, are available to menu contributions.
After the locationURI specifies the insertion point, the <menuContribution/>
elements are turned into IContributionItems and inserted in order. Another
difference between menu contributions and action contributions is that the menu
contributions can be defined in the XML in the same kind of containing relationship
that one would would see in a menu or toolbar.
Let's start with a simple example from our Info example, adding some commands
to the InfoView.
<extension
point="org.eclipse.ui.menus">
<menuContribution
locationURI="menu:org.eclipse.ui.examples.contributions.view?after=additions">
<command
commandId="org.eclipse.ui.examples.contributions.view.count"
mnemonic="%contributions.view.count.mnemonic">
</command>
<command
commandId="org.eclipse.ui.examples.contributions.view.edit"
mnemonic="%contributions.view.edit.mnemonic">
</command>
<command
commandId="org.eclipse.ui.file.refresh"
mnemonic="%contributions.view.refresh.mnemonic">
</command>
</menuContribution>
...
Our locationURI marks this contribution for the org.eclipse.ui.examples.contributions.view
view. Here we are adding 3 commands to the InfoView dropdown menu: Count Entries,
Edit, and Refresh.
Although you can specify a label in the menu
contribution <command/> element, if you don't we will use the name
attribute from the
org.eclipse.ui.commands
command definition. Now clicking on the menu element will execute that command.
We've also placed a command in the InfoView toolbar:
<menuContribution
locationURI="toolbar:org.eclipse.ui.examples.contributions.view?after=additions">
<command
commandId="org.eclipse.ui.examples.contributions.view.swap"
label="%contributions.view.swap.name"
tooltip="%contributions.view.swap.tooltip">
</command>
</menuContribution>
Note: this command will appear in the view's toolbar. To place the same command in the
main toolbar, you have to create the toolbar as well by including a <toolbar/> element
in the <menuContribution/> to contain the command.
The "Swap Entries" button on the toolbar will be
disabled until 2 Person entries are selected in the
info view because we defined an <enabledWhen> expression
in the handler definition:
<enabledWhen>
<count
value="2">
</count>
</enabledWhen>
Contribution visibility
A command's enabled state is controlled by a combination of the command
is handled and if so, the handler's enabled state. Menu contributions
can use core expressions to control the command's visibility in menus and
toolbars.
As an example, menu contributions can still be tied to an existing action
set while being contributed to the main menu or main toolbar, as action sets
are converted into contexts. In this example
we place our command in the main menu and main toolbar.
<extension
point="org.eclipse.ui.actionSets">
<actionSet
id="org.eclipse.ui.examples.contributions.globalActionSet"
label="%contributions.globalActionSet.label"
visible="false">
</actionSet>
</extension>
<extension
point="org.eclipse.core.expressions.definitions">
<definition
id="org.eclipse.ui.examples.contributions.inGlobalActionSet">
<with
variable="activeContexts">
<iterate
operator="or">
<equals
value="org.eclipse.ui.examples.contributions.globalActionSet">
</equals>
</iterate>
</with>
</definition>
...
The above XML defines the action set to use, and a definition for a core expression
that checks contexts to see if the action set is active. See the
org.eclipse.ui.handlers section for other examples of core
expressions.
Now we can add our command to the main menu:
<menuContribution
locationURI="menu:org.eclipse.ui.main.menu?after=additions">
<menu
label="%contributions.menus.globalMenu.label"
mnemonic="%contributions.menus.globalMenu.label"
id="org.eclipse.ui.examples.contributions.menus.globalMenu">
<command
commandId="org.eclipse.ui.examples.contributions.commands.globalCommand"
mnemonic="%contributions.menus.globalCommand.mnemonic"
id="org.eclipse.ui.examples.contributions.menus.globalCommand">
<visibleWhen>
<reference
definitionId="org.eclipse.ui.examples.contributions.inGlobalActionSet">
</reference>
</visibleWhen>
</command>
<separator
name="additions"
visible="false">
</separator>
</menu>
</menuContribution>
<menuContribution
locationURI="toolbar:org.eclipse.ui.main.toolbar?after=additions">
<toolbar
id="org.eclipse.ui.examples.contributions.toolbars.sampleToolbar">
<command
commandId="org.eclipse.ui.examples.contributions.commands.globalCommand"
icon="icons/sample.gif"
tooltip="%contributions.toolbars.globalCommand.tooltip"
id="org.eclipse.ui.examples.contributions.toolbars.globalCommand">
<visibleWhen>
<reference
definitionId="org.eclipse.ui.examples.contributions.inGlobalActionSet">
</reference>
</visibleWhen>
</command>
<separator
name="additions"
visible="false">
</separator>
</toolbar>
</menuContribution>
...
In the above XML, we are adding the menu "Global Menu" to the main menu,
and then placing the "Global Command" in it. The <visibleWhen/>
element will evaluate the body of the previously defined inGlobalActionSet
core expression. The <separator/> element adds and additions group
that can be used by other contributions. We are also creating a toolbar
in the main coolbar (org.eclipse.ui.main.toolbar) and placing a our command
in it with the sample.gif icon.
Other contributions can now contribute to the "Global Menu"
menu by specifying its id as a contribution locationURI:
menu:org.eclipse.ui.examples.contributions.menus.globalMenu?after=additions.
Currently, commands contributed to action sets don't show up in the
Window > Customize Perspective...
dialog.
You can add menu contributions that work similar to org.eclipse.ui.editorActions.
First you define your editor command and handler, like Reset. Then you can
add them in an editor menu like "Info" to the main menu:
... org.eclipse.core.expressions.definitions
<definition
id="org.eclipse.ui.examples.contributions.view.activeEditor">
<with
variable="activeEditorId">
<equals
value="org.eclipse.ui.examples.contributions.editor">
</equals>
</with>
</definition>
... org.eclipse.ui.menus
<menuContribution
locationURI="menu:org.eclipse.ui.main.menu?after=additions">
<menu
id="org.eclipse.ui.examples.contributions.editor.menu"
label="%contributions.editor.menu.label"
mnemonic="%contributions.editor.menu.mnemonic">
<command
commandId="org.eclipse.ui.examples.contributions.editor.reset"
mnemonic="%contributions.editor.reset.mnemonic">
<visibleWhen>
<reference
definitionId="org.eclipse.ui.examples.contributions.view.activeEditor">
</reference>
</visibleWhen>
</command>
</menu>
</menuContribution>
This is similar to adding to the main menu with our global action example.
Here our core expression
will make this element visible as long as the active editor id variable
matches our editor. You can check out
org.eclipse.ui.ISources
for a list of supported variables names.
Note: updating the main menu and especially the main toolbar are expensive
operations. You generally want to confine them to actionSet equivalent contexts
and active editor type. Although you can update the main toolbar on each
selection change using the default variable or a <with variable="selection"/>
expression, it's not a good idea. The common practice is to leave your command
visibility at the action set or active editor level, and have your handler
enabled state track the current selection.
Contributing to popup menus
As in
org.eclipse.ui.popupMenus,
commands can be contributed to a specific context menu by the context menu's id, or to any
context menu where it can satisfy its <visibleWhen> clause. For example, we can add
our Refresh command to the Info View popup as a convenience. Because we didn't call
registerContextMenu(*)
with a specific id it defaults to the view id.
<menuContribution
locationURI="popup:org.eclipse.ui.examples.contributions.view?after=additions">
<command
commandId="org.eclipse.ui.file.refresh"
mnemonic="%contributions.view.refresh.mnemonic">
</command>
</menuContribution>
To contribute a command to a popup if its selection matches a particular object type you
can use the default variable, or for behaviour closest to org.eclipse.ui.popupMenus
target a specific popup selection variable. Here's an example using the context menu
selection provider. This just effects the popup menu visibility, not the command
enabled state.
<menuContribution
locationURI="popup:org.eclipse.ui.popup.any?after=additions">
<command
commandId="org.eclipse.ui.examples.contributions.view.edit"
mnemonic="%contributions.view.edit.mnemonic">
<visibleWhen>
<with
variable="activeMenuSelection">
<iterate>
<adapt
type="org.eclipse.ui.examples.contributions.model.Person">
</adapt>
</iterate>
</with>
</visibleWhen>
</command>
</menuContribution>
Using <iterate><adapt type="Person"/></iterate> is
the core expression equivalent of the old objectClass attribute.
Adding toolbars to trim areas
A 'trim' widget is a control that gets sited into a location (called a 'Trim Area') on the outer boundary of the Workbench Window. The
most common example is the generic 'status line' which almost all GUI's place along the bottom of the window.
The extension point
org.eclipse.ui.menus
allows plug-ins to add elements to the workbench trim by contributing toolbars into trim areas and populating the toolbar with
one or more controls (using the same mechanism as contributing controls into the main toolbar).
Controls contributed to the trim must be a subclass of
WorkbenchWindowControlContribution
.
This class will manage the life-cycle of the contribution, disposing and re-creating the contribution as necessary (such as when the user moves the control to another trim area). Note that the getCurSide()
and getOrientation()
methods
allow the implementation of createControl(parent)
to adjust the created control to it's current locaton in the trim.
For this example we've contributed a fairly naive trim widget that simply displays a string and an indication of which side the trim iscurrently docked on.
Let's take a look at the extension point definition used to contribute this piece of trim:
<menuContribution
locationURI="toolbar:org.eclipse.ui.trim.status">
<toolbar
id="org.eclipse.ui.examples.contributions.contributedTrim">
<command
commandId="org.eclipse.ui.examples.contributions.item2"
icon="icons/editor.gif"
id="contributions.trimItem"
label="%Trim.item"
tooltip="%TrimItem.toolTip">
</command>
<control
class="org.eclipse.ui.examples.contributions.ExampleControlContribution"
id="contributions.controlContrib1">
</control>
<command
commandId="org.eclipse.ui.examples.contributions.item2"
icon="icons/editor.gif"
id="contributions.trimItem2"
label="%Trim2.item"
tooltip="%TrimItem2.toolTip">
</command>
</toolbar>
</menuContribution>
This extension defines the 'locationURI' for this extension; identifying it as being at the start of the 'status' trim area (i.e. at the beginning of the bottom). We then define a toolbar contribution at that location, adding a control
contribution bracketed by two command contributions directly into its definition.
One thing that is not reflected in this sample's code is the reliance of the trim layout manager on the trim control's proper implementation of the widget control's computeSize
method. The widget must be capable of calculating and returning its 'preferred' size since this is used throughout the layout management implementation to determine, for example, how much space is needed for a particular trim area.
For example, if you want to contribute a Text input control to the trim (i.e. a 'Search Bar') and you want to control the width it has you'll need to wrap the Text control in a Composite whose Layout's 'computeSize' returns the correct values.
See the SWT documentation for notes on how to correctly implement 'computeSize
' correctly.