Revision as of 15:48, 24 December 2012

Placement examples that describe the proposed new way of placing menu items for 3.3. Please contribute comments and suggestions in the discussion area or on Bug 154130 -KeyBindings- Finish re-work of commands and key bindings.

Placement and visibility

The 4 extension points that deal with menus now org.eclipse.ui.actionSets, org.eclipse.ui.viewActions, org.eclipse.ui.editorActions, and org.eclipse.ui.popupMenus specify both menu placement and their visibility criteria. In the new menu mechanism they are separate concepts, placement and visibility.

Example Matrix

A (hopefully) growing list of menu contribution examples.

Menu XML

Declarative information ... this needs to be cleaned up.

Declarative menus - some constraints

Some constraints on the system:

1. Identifiers (id) for <menu/> elements must be globally unique.
2. Identifiers (id) for <command/> elements must be globally unique if they are specified.
3. You can reference a <menu/> by id.
4. If you are just creating menu items for your commands, you can leave them with only a command id. You don't have to specify an item id.
5. You can reference a <command/> for placement options (after, before, etc.) by id.
6. <separator/> ids only have to be unique within that menu level. This is changed to name instead of id in 3.3M5.
7. You can provide a <command/> label attribute. If none is provided, it will take the command name.
8. In this design the item contains most of the same rendering information that <action/> did.
9. <menu/> and <command/> can have <visibleWhen/> clauses. If a menu's <visibleWhen/> evaluates to false, we will never ask the items contained in that menu.
10. All of the displayable attributes are translatable.
11. The mnemonic is specified as you place your <command/> elements in their respective menus, since it is possible that the same command might need a different mnemonic depending on which menu it is placed. Also, when defaulting to command names, they don't contain any mnemonic information.

Menus cannot be re-used, and so they have an intrinsic id value. Separators are unique within one menu level, so they also contain their name.

Menu URIs

For location placement we need a path and placement modifier, and to specify how the paths are built. First pass we are going to look at URIs.

• <scheme>:<menu-id>[?<placement-modifier>]

scheme is about how to interpret the URI path. For example, menu, toolbar, popup, status (although status may be deprecated).

menu:

For menu: valid root ids will be any viewId for that view's menu, and org.eclipse.ui.main.menu for the main menu. Then specify the id of the menu this contribution applies to. The placement modifier helps position the menu contribution. ex: after=<id>, where <id> can be a separator name, menu id, or item id. An example of a path: menu:org.eclipse.search.menu?after=contextMenuActionsGroup

Since menu ids must be unique, you can specify your menu location relative to an existing id: menu:org.eclipse.search.menu?after=contextMenuActionsGroup

toolbar:

For toolbar: valid root ids will be any viewId for that view's toolbar, org.eclipse.ui.main.toolbar for the main toolbar, and any toolbar id that is contained in the main toolbar. Toolbars can support invisible separators. Toolbars in the main toolbar (technically a coolbar) can have ids as well as separators, but only one level. For example: toolbar:org.eclipse.ui.edit.text.actionSet.presentation?after=Presentation

In this example, Presentation is an invisible separator in the org.eclipse.ui.edit.text.actionSet.presentation toolbar.

The use of org.eclipse.ui.main.toolbar might change if all "main" toolbars have ids anyway, so the only options for interpretting the toolbar root is 1) the view toolbar or 2) an IDed main toolbar.

popup:

For popup: valid root ids are any registered context id (which defaults to the part id if no context menu id was given at registration time) and org.eclipse.ui.popup.any for all registered context menus. For example, to add to the default Text Editor context menu: popup:#TextEditorContext?after=additions

Popup submenus are treated like menu submenus, except the form continues to be popup:submenuId.

There will be constants defined for the ids that the eclipse workbench provides, probably in org.eclipse.ui.menus.MenuUtil.

Using Expressions in <visibleWhen/>

In 3.3M6 an org.eclipse.core.expressions.definitions extension point was added. Used to define a core expression, the definition can then be referenced from other locations.

<extension point="org.eclipse.core.expressions.definitions">
  <definition id="com.example.context">
    <with variable="activeContexts">
       <iterate operator="or">
         <equals value="org.eclipse.ui.contexts.actionSet"/>
       </iterate>
    </with>
  </definition>
</extension>

This can be called in a core expression like activeWhen, enabledWhen, visibleWhen, etc using the reference element:

<reference definitionId="com.example.context"/>

Ideas that were considered but not implemented

These ideas were considered but not implemented.

Menu - JSR198

Note: for novelty purposes only.

For comparison, there is a JSR describing how IDEs can contribute menus. Below is a sample for 2 items:

• org.eclipse.ui.views.problems.sorting.item from menu:org.eclipse.ui.views.ProblemView
• org.eclipse.ui.views.problems.resolveMarker.item from popup:org.eclipse.ui.views.ProblemView

<menu-hook>
  <actions>
    <action id="org.eclipse.ui.views.problems.sorting.item">
      <label>Sorting...</label>
      <mnemonic>S</mnemonic>
      <tooltip>Change the Sort order</tooltip>
      <invoke-class>org.eclipse.ui.views.problems.sorting</invoke-class>
    </action>
    <action id="org.eclipse.ui.views.problems.resolveMarker.item">
      <label>Quick Fix</label>
      <mnemonic>Q</mnemonic>
      <iconpath>$nl$/icons/full/elcl16/smartmode_co.gif</iconpath>
      <invoke-class>org.eclipse.jdt.ui.edit.text.java.correction.assist.proposals</invoke-class>
      <update-class>org.eclipse.jdt.ui.edit.text.java.correction.assist.proposals</update-class>
    </action>
  </actions>
  <menus>
    <menubar id="org.eclipse.ui.views.ProblemView">
      <menu id="org.eclipse.ui.views.ProblemView">
        <section id="problem.view.section">
          <command action-ref="org.eclipse.ui.views.problems.sorting.item" />
          <menu id="org.eclipse.ui.views.problems.groupBy.menu">
            <label>Group By</label>
            <mnemonic>G</mnemonic>
          </menu>
        </section>
      </menu>
    </menubar>
    <popup id="org.eclipse.ui.views.ProblemView">
      <section id="group.resolve">
        <command action-ref="org.eclipse.ui.views.problems.resolveMarker.item" />
      </section>
    </popup>
  </menus>
</menu-hook>

Some thoughts:

• the actions can only specify one icon
• the actions can't *quite* link to our commands
• the menus can't specify dynamic submenus

Menu - XUL

Note: for novelty purposes only.

For comparison, with Mozilla everywhere there is the probability eclipse will include xulrunner. Menu definitions that are consistent with XUL look like:

<keyset>
  <key id="paste-key" modifiers="accel" key="V" />
</keyset>
<menubar id="org.eclipse.ui.views.ProblemView">
  <menupopup id="org.eclipse.ui.views.ProblemView">
    <menuitem id="org.eclipse.ui.views.problems.sorting.item"
        accesskey="S"
        key="paste-key"
        label="Sorting..."
        oncommand="invokeCommand('org.eclipse.ui.views.problems.sorting')" />
    <menu id="org.eclipse.ui.views.problems.groupBy.menu"
        label="Group By"
        accesskey="G">
      <menupopup id="groupby.popup">
        <!-- this is where submenu items would go -->
      </menupopup>
    </menu>
  </menupopup>
</menubar>

XUL supports everything as a flavour of a DOM, and javascripting can drive your buttons to perform commands. I suspect the scripting would allow you to dynamically update menus (dynamic menus) on popup, depending on what events the DOM would report to you.

Expression Templates original suggestion

You can see that the <activeWhen/>, <enabledWhen/>, and probably the <visibleWhen/> are likely to be replicated over and over again. A possible option is some kind of expression template markup ... either in its own extension or supported by our UI extensions that can use core expressions.

Here's an example of using expression templates in its own extension point.

<extension point="org.eclipse.core.expression.templates">
  <expression id="isPartActive">
    <parameter id="partId" />
    <with variable="activePartId">
      <equals value="$partId" />
    </with>
  </expression>
  <expression id="isActionSetActive">
    <parameter id="actionSetId" />
    <with variable="activeContexts">
      <iterator operator="or">
        <equals value="$actionSetId" />
      </iterator>
    </with>
  </expression>
  <expression id="isContextActive">
    <parameter id="contextId" />
    <with variable="activeContexts">
      <iterator operator="or">
        <equals value="$contextId" />
      </iterator>
    </with>
  </expression>
  <expression id="isSelectionAvailable">
    <not>
      <count value="0" />
    </not>
  </expression>
</extension>

This could be used to simplify the handler definitions:

<extension point="org.eclipse.ui.handlers">
  <handler commandId="org.eclipse.ui.edit.copy"
      class="org.eclipse.ui.views.markers.internal.CopyMarkerHandler">
    <enabledWhen>
      <evaluate ref="isSelectionAvailable" />
    </enabledWhen>
    <activeWhen>
      <evaluate ref="isPartActive">
        <parameter id="partId" value="org.eclipse.ui.views.ProblemView" />
      </evaluate>
    </activeWhen>
  </handler>
</extension>

If we allow recursive template definitions, that would allow you to specify the concrete expression once and then reference it throughout your view.

<extension point="org.eclipse.core.expression.templates">
  <expression id="isProblemViewActive">
    <evaluate ref="isPartActive">
      <parameter id="partId" value="org.eclipse.ui.views.ProblemView" />
    </evaluate>
  </expression>
</extension>
<extension point="org.eclipse.ui.handlers">
  <handler commandId="org.eclipse.ui.edit.copy"
      class="org.eclipse.ui.views.markers.internal.CopyMarkerHandler">
    <enabledWhen>
      <evaluate ref="isSelectionAvailable" />
    </enabledWhen>
    <activeWhen>
      <evaluate ref="isProblemViewActive" />
    </activeWhen>
  </handler>
</extension>

This reduces the handler definition even more.

A similar option to reuse expressions as much as possible without turning them into their own procedural language would be to allow global definitions and then reuse them. No parameters and no expression composition:

<extension point="org.eclipse.core.expression.templates">
  <expression id="isProblemViewActive">
    <with variable="activePartId">
      <equals value="org.eclipse.ui.views.ProblemView" />
    </with>
  </expression>
  <expression id="isSelectionAvailable">
    <not>
      <count value="0" />
    </not>
  </expression>
</extension>
<extension point="org.eclipse.ui.handlers">
  <handler commandId="org.eclipse.ui.edit.copy"
      class="org.eclipse.ui.views.markers.internal.CopyMarkerHandler">
    <enabledWhen ref="isSelectionAvailable" />
    <activeWhen ref="isProblemViewActive" />
  </handler>
</extension>

Another Expression Alternative: Specify Context at Extension Level

Since enabledWhen and activeWhen specify context and the simple way to specify context in XML is enclosure, how about scoping context to the extension point rather than the handler:

<extension point="org.eclipse.ui.handlers">
  <enabledWhen>  <!-- context of all  handlers in this extension -->
    <not>
      <count value="0" />
    </not>
  </enabledWhen>
  <activeWhen>
    <with variable="activePartId">
      <equals value="org.eclipse.ui.views.ProblemView" />
    </with>
  </activeWhen>
  <handler commandId="org.eclipse.ui.edit.copy"
      class="org.eclipse.ui.views.markers.internal.CopyMarkerHandler" />
  <handler commandId="org.eclipse.ui.edit.paste"
      class="org.eclipse.ui.views.markers.internal.PasteMarkerHandler" />
  <handler commandId="org.eclipse.ui.edit.delete"
      class="org.eclipse.ui.views.markers.internal.RemoveMarkerHandler" />
  <handler commandId="org.eclipse.jdt.ui.edit.text.java.correction.assist.proposals"
      class="org.eclipse.ui.views.markers.internal.ResolveMarkerHandler" />
  <handler commandId="org.eclipse.ui.edit.selectAll"
      class="org.eclipse.ui.views.markers.internal.SelectAllMarkersHandler" />
  <handler commandId="org.eclipse.ui.file.properties"
      class="org.eclipse.ui.views.markers.internal.ProblemPropertiesHandler" />
</extension>

This gives compact markup without inventing a new language. Elements nested in the handler element could override the extension-wide settings.

Updating the menu and toolbar appearance

It was suggested in 3.2 that state on the command could be used to implement the old contribution story behaviours:

1. changing label text and tooltips
2. changing icons
3. changing enablement
4. setting the item state (like checked state)

In 3.3 the enablement is tied to the command, and for the other behaviours we've decided to go with UIElements approach.

UIElements represent each UI visible instance of a command

The command service keeps a list of registered UI elements, which can be updated by the active handler. The checked state can be updated through UIElement#setChecked(boolean); (note that updateElement below is from IElementUpdater):

private boolean isChecked() {
    return getStore().getBoolean(
            PreferenceConstants.EDITOR_MARK_OCCURRENCES);
}
 
public void updateElement(UIElement element, Map parameters) {
    element.setChecked(isChecked());
}

When the toggle handler runs, it can request that any UI elements have their appearance updated from its execute(*) method:

ICommandService service = (ICommandService) serviceLocator
        .getService(ICommandService.class);
service.refreshElements(IJavaEditorActionDefinitionIds.TOGGLE_MARK_OCCURRENCES, null);

State associated with the command is propogated to UI visible elements

First define the toggle mark occurrences command. Pretty straight forward, although it needs a "STYLE" state since it can be toggled. To allow handlers to update the label for the menu/toolbar items, we also add the "NAME" state.

<extension point="org.eclipse.ui.commands">
  <command categoryId="org.eclipse.jdt.ui.category.source"
      description="%jdt.ui.ToggleMarkOccurrences.description"
      id="org.eclipse.jdt.ui.edit.text.java.toggleMarkOccurrences"
      name="%jdt.ui.ToggleMarkOccurrences.name">
    <state id="NAME" class="org.eclipse.jface.menus.TextState" />
    <state id="STYLE" class="org.eclipse.jface.commands.ToggleState:true" />
  </command>
</extension>

Work

Progress in 3.3.

Available in 3.3

• the editor action bar contributor solution. EditorActionBarContributor will not be deprecated, but is not used in the commands/handler story. Menu Contributions have visibility tied to an active editor id, and editor specific handlers can be created in the editor init(*) or createPartControl(*) method using the handler service from getPartSite().getService(IHandlerService.class).
• Attributes for <command/>: helpContextId, style to support radio buttons and check boxes
• action sets as contexts - action sets are still defined using org.eclipse.ui.actionSets, and each actionSet generates an equivalent context. showing/hiding actionSets activates/deactivates the equivalent context.
• How do we give Trim widgets/toolbar widgets "focus" for command and handlers? There was an IFocusService added in 3.3 that allows a trim control to register itself. When that control has focus, the control and the ID it registered with are provided in the global application context to core expressions and handlers. This is available, but might not be the optimal solution if you just want cut, copy, and paste to work.
• Shortcuts to define reusable core expressions for <activeWhen/>, <enabledWhen/>, and <visibleWhen/>. This has been added as the org.eclipse.core.expressions.definitions extension point and the core expression <reference/> element.
• the mnemonic field for <command/> elements (decorating)
• display any keybinding for <command/> elements (decorating)
• toolbar <visibleWhen/> expressions

Available in 3.3M5

There is an example of the RCP Mail application template updated for 3.3M5 and converted to use the org.eclipse.ui.menus extension point as much as possible at Contribution Example.

• changing the menu item or tool item state from a handler, like updating the label or tooltip or checked state. Commands can contain <state/> elements, but that is not appropriate to use for providing feedback to the user. This will be done by adapting a callback provided by the UI element.
• the <separator/> element should have a name not an id
• support creating radio button or checked menu items
• creating new toolbars in the main coolbar/trim declaratively
• creating new toolbars in the main coolbar/trim programmatically
• org.eclipse.ui.popup.any as a context menu contribution
• Drop down toolbar items

We also have action sets activating and de-activating contexts in 3.3M5, but we'll need to decide the proper action set story for 3.3M6

We are still working on the EditorActionBarContributor story. It seems like we might be able to deprecate it. Editor instances can instantiate handlers upon creation for each command they support.

Available in 3.3M4

The basic menu API will be available in 3.3M4. It includes both declarative org.eclipse.ui.menus extension point with core expression support for visibility, and a programmatic interface accessed through the IMenuService.

We support contributing to the main menu, and the view menu, view toolbar, and any IDed context menu. We support contributing to existing toolbars in the main coolbar, and contributing trim widgets.

Programmatically we support the following types of contributions:

• MenuManager
• CommandContributionItem
• CompoundContributionItem
• ControlContribution (in 3.3M5)
• Separator
• GroupMarker

There are some specific mappings of elements and attributes on Menus Extension Mapping.

Work still to be done

A list of behaviours not supported or shipped with 3.3.

• validate and possibly optimize the context menu population story and lifecycle. Many context menus set remove all when shown.
• migrate Marker views
• migrate standard workbench actions - a few were done
• Check enabled visibleWhen support
• Shortcuts placed on submenu items (like CTRL+N) (decorating)
• ensure full visibleWhen support in the MenuManagers - i.e. should empty menus display (empty)
• do we want to manage trim with a TrimContributionManager? This removes the coolbar, but has RCP implications.
• the menu override capability - does this tie into the Customize Perspective dialog and action sets
• A set of default programmatic core expressions. For example, ActionContextExpression or ActivePartExpression
• deprecate the 4 extension: actionSets, viewActions, editorActions, popupMenus
• read old extensions in terms of new extension
• convert platform UI extensions to new extension
• migration guide - what are the most common migration paths for Action and IActionDelegate to Command/IHandler.
• Attributes for <command/>: state for checkboxes and radio buttons
• possibly provide an plugin.xml converter for actionSets to menus
• possibly provide an Action -> Handler converter
• status manager contributions

Legend:

• nothing - TBD
• - investigating
• - in progress
• - completed
• - dropped