Re: UIManager and dynamic menus

["Paul Davis" <pjdavis engineering uiowa edu>]

On 4/4/07, Paul Davis <paul linuxaudiosystems com> wrote:
> On Wed, 2007-04-04 at 11:27 -0500, Paul Davis wrote:
> > Hi list,
> >
> > I've been working with UIManager quite a bit lately and I've come up
> > against two issues that are fairly related.
> >
> > What is the 'UIManager' way of having dynamic menus. I need this when
> > adding a list of recent documents to the File menu or when creating a
> > list of windows for a View menu.
> >
> > I've looked at the merge operations presented by UIManager, but they
> > appear to be a bit heavier weight than I would expect for something
> > like this.
> >
> > If this merge/unmerge functionality is the way to go, does someone
> > have a good example of doing this.  I'm fairly certain I get the
> > basics, but having a good example is always nice too.
>
> if one of us hasn't been there already, i'm not sure what we would do :)
>
> personally, i have found it *extremely* hard to use the UIManager for
> dynamic menus. the problems have been subtle, and i gave up. my approach
> now is to use UIManager for the static menus (including a dangling menu
> item where the dynamic one will be "hung"), and then do this:
>
> Gtk::Menu*
> SequencerUI::get_trigger_submenu ()
> {
>         Widget* foo = ActionManager::get_widget ("/Main/Triggers/Edit");
>         Gtk::MenuItem* foomi = dynamic_cast<MenuItem*>(foo);
>         return foomi->get_submenu ();
> }
>
> after that, i use the very nice Menu_Helpers function to rebuild the
> item list for the return menu (including a clear):
>
> int
> SequencerUI::add_trigger_item (Trigger &trigger)
> {
>         using namespace Menu_Helpers;
>         Gtk::Menu* trigger_menu = get_trigger_submenu();
>         MenuList& trigger_list = trigger_menu->items();
>
>         trigger_list.push_back (MenuElem (trigger.name().c_str(), bind (mem_fun
> (*this, &SequencerUI::edit_trigger), &trigger)));
>         trigger_list.back().set_data ("trigger_ptr", &trigger);
>
>         return 0;
> }
>
> void
> SequencerUI::rebuild_trigger_submenu ()
> {
>         using namespace Menu_Helpers;
>         Gtk::Menu* trigger_menu = get_trigger_submenu();
>         MenuList& items = trigger_menu->items();
>
>         items.clear ();
>
>         _sequencer->foreach_trigger (*this, &SequencerUI::add_trigger_item);
>
>         trigger_menu->show_all ();
> }
>
> i just couldn't figure out a way to smoothly accomplish the same thing
> with readable and grokkable code.
>
> --p

Other me,

Yeah you were right in that this was extremely frustrating.  I think
it'd be possible to get this working if if I fiddled with the
UIManager or wrote some stuff on top of it to make it behave the way I
thought it should, but right now its just too irritating to work with.

In other news, how did you set up your ui_info string that you pass to
Gtk::UIManager::add_ui_from_string() ; ?

If I don't do something like this:

       "       <menu action='ViewMenu'>"
       "           <menuitem action='ViewDefaultSize' />"
       "           <menuitem action='ViewFullScreen' />"
       "           <separator />"
       "           <menu action='ViewWindowsMenu'>"
       "               <menuitem action='TestItem' />"
       "           </menu>"
       "       </menu>"

If I don't have a menuitem in the 'ViewWindowsMenu' then it doesn't
show up at all.  I tried calling show() on it and everything, but I
have the sneaking suspicion that its just not added to the parent menu
till you add a child.

Anyway its working, but its kinda hackish.

Perhaps we might think about trying to add some better dynamic
functionality to this in the future when we're planning an API/ABI
break, but it just doesn't seem worth it right now.

Thanks,
Paul Davis