How to add a pulldown button in a view's toolbar?

I need to add a pulldown button to a view's toolbar in an Eclipse plugin.

Actually buttons in the toolbar are added like that :

<extension point="org.eclipse.ui.viewActions">
  <viewContribution id="..." targetId="$MyViewId$">
    <action id="..."
            toolbarPath="action1"
            class="Class extending Action and implementin开发者_高级运维g IViewActionDelegate">
    </action>
  </viewContribution>
</extension>

I've figured it out. Two ways: one using org.eclipse.ui.viewActions extension, the other with org.eclipse.ui.menus

Using org.eclipse.ui.viewActions extension (eclipse >= 3.5)

• action's style must set to pulldown

    <extension point="org.eclipse.ui.viewActions">
      <viewContribution id="..." targetId="$MyViewId$">
        <action id="..."
                toolbarPath="action1"
                class="xxx.MyAction"
                style="pulldown">
        </action>
      </viewContribution>
    </extension>

• action class must implement IViewActionDelegate (required for an action contributing to a view toolbar) and IMenuCreator (defines the menu behavior).

    public class RetrieveViolationsViewActionDelegate implements IViewActionDelegate, IMenuCreator
    {
      private IAction action;
      private Menu menu;

      // IViewActionDelegate methods
      ...

      // IMenuCreator methods
      public void selectionChanged(IAction action, ISelection selection)
      {
        if (action != this.action)
        {
          action.setMenuCreator(this);
          this.action = action;
        }
      }

      public void dispose()
      {
        if (menu != null)
        {
          menu.dispose();
        }
      }

      public Menu getMenu(Control parent)
      {
        Menu menu = new Menu(parent);
        addActionToMenu(menu, new ClassImplemententingIAction());
        return menu;
      }

      public Menu getMenu(Menu parent)
      {
        // Not use
        return null;
      }



      private void addActionToMenu(Menu menu, IAction action)
      {
        ActionContributionItem item= new ActionContributionItem(action);
        item.fill(menu, -1);
      }
    }

Using org.eclipse.ui.menus (eclipse >= 3.3)

• Add a new menucontribution to the org.eclipse.ui.menus extension point.
• Set the location URI to toolbar:IdOfYourView
• Add a toolbar to this extension and a new command to this new toolbar.
• Change the command style to pulldown
• Create a new menucontribution and set the locationURI to menu:IdOfThePullDownCommand
• Add commands to this menu.

More info