Creating toolbar items pulldown menu-entries programmatically

Question

I searched all over the net but couldn't find a working solution how to create pull-down menu entries for a menu item in a toolbar in Eclipse programmatically. To create them using plugin.xml is smooth, but is there some way to do it from code? Why to do that?

I want to create a little plugin which offers the user the possibility to create a random number of entries which should be accessible thru a single menu item (button) with a pull-down menu in the main toolbar.

I'm quite new to Eclipse plugin development. As I already said doing in plugin.xml is no problem :

   <extension point="org.eclipse.ui.menus">
      <menuContribution     locationURI="toolbar:org.eclipse.ui.main.toolbar?after=additions">
         <toolbar id="pulldown.items.toolbars.sampleToolbar">
            <command
                  commandId="pulldown.items.commands.sampleCommand"
                  icon="icons/sample.gif"
                  tooltip="Say hello world"
                  id="pulldown.items.toolbars.sampleCommand"
                  style="pulldown">
            </command>
         </toolbar>
      </menuContribution>
      <menuContribution locationURI="menu:pulldown.items.toolbars.sampleCommand">
            <command 
                commandId="pulldown.items.commands.sampleCommand"
                label="Message 1" style="push">
                    <parameter name="pulldown.items.msg" value="Some message"/>
            </command>
            <separator name="nothing" visible="false"/>
            <command 
                commandId="pulldown.items.commands.sampleCommand"
                label="Message 2" style="push">
                <parameter name="pulldown.items.msg" value="Some other message"/>
            </command>
      </menuContribution>
</extension>

I tried to find the information about this commands in the following objects but couldn't find any. Don't bother me using getWorkbenchWindows()[0] this code is executed on plugin startup and there is no active window available.

Activator act = Activator.getDefault();
IWorkbench workbench = act.getWorkbench();
WorkbenchWindow window = (WorkbenchWindow)workbench.getWorkbenchWindows()[0];
CoolBarManager cbm = window.getCoolBarManager();
ToolBarContributionItem item =         
    (ToolBarContributionItem)cbm.find("pulldown.items.toolbars.SampleToolbar");
IToolBarManager tbm = item.getToolBarManager();
CommandContributionItem citem = 
    (CommandContributionItem)tbm.find("pulldown.items.toolbars.sampleCommand");
ParameterizedCommand cmd = citem.getCommand();

All objects are valid but they contain neither one of the above defined parameterized commands. All parameters in the commands I could find are only containing the definition but no value is specified.

Answer 1

Have a look at the class attribute of the menuContribution element. Via a this you can write a Java class (extending org.eclipse.ui.menus.ExtensionContributionFactory ) that will contribute the wanted menu entries dynamically. In this case all sub-elements of the menuContribution will be ignored.

Answer 2

作为提供整个ExtensionsContributionFactory的替代方法（可以正常工作），您可以在现有XML中添加dynamic元素，然后提供CompoundContributionItem来创建工具项下拉列表的动态部分。