How to create drop down menu's in eclipse rcp according to alphabets dynamically - eclipse

Question

I want to create dropdown menu in eclipse rcp by alphabetical order, those dropdown menu's needs to be arranged according to alphabets.
Such that under main menu I want show alphabets. if there is any contribution related to alphabet then I have to create a dropdown menu under that alphabet.
// Use case
Menu
A -> Action,
B -> Bind,
C -> Click
Please have a look into the attached use case diagram

Answer 1

If you are in e4, in the Application.e4xmi model, add to a "Menu" a "Dynamic Menu Contribution"
Link this dynamic menu to a class that will build the menu like this:
public class DynamicMenuContributor {
#Inject
private EModelService modelService;
#AboutToShow
public void aboutToShow(List<MMenuElement> items) {
for (String s : <your collection of letters>) {
MDirectMenuItem dynamicItem = modelService.createModelElement(MDirectMenuItem.class);
dynamicItem.setLabel(s);
dynamicItem.setContributorURI(<contributor uri>);
dynamicItem.setContributionURI(<point the class that will handle the menu event>);
// dynamicItem.setType(ItemType.RADIO);
// dynamicItem.setSelected(selected);
// dynamicItem.setIconURI(<url to icon>);
// dynamicItem.getTransientData().put(<param1 name>, <param1 value>);
// dynamicItem.getTransientData().put(<param2 name>, <param2value>);
items.add(dynamicItem);
}
}
}
With a class to handle the event like this:
public class DynamicMenuSelectiontHandler {
#Execute
public void execute(MMenuItem menuItem) {
<param1> = menuItem.getTransientData().get(<param 1 name>);
<param2> = menuItem.getTransientData().get(<param 2 name>);
<put your logic here>
}
}