Re: [gtk-list] Gtk--: Upgrading from MenuFactory to ItemFactory

[Tero Pulkkinen <terop students cc tut fi>]

Robert_Gasch/PeopleSoft@peoplesoft.com writes:
> -- I'm now doing this:
> static GtkItemFactoryEntry menu_items[] = {
> {"/File",           0, 0, 0, "<Branch>" },
> {"/File/New",  0, 0, 0, 0 },
> {"/File/Open",      0, 0, 0, 0 } };

The problem is that this kind of table of menuitems did not work well with
C++'s type checking etc... The types of callbacks are different and cannot
be easily placed to this kind of array without breaking type safety.

Use several create_item -calls instead:
void tc::cb1(gint) {
  ..
}

void scb() {
 ..
}
  d_menuFactory->create_item ("/File", 0, "<Separator>", this, &tc::cb1, 0); 
  d_menuFactory->create_item ("/File", 0, "<Separator>", &scb); 

This only works if your C++ compiler supports member templates, if not,
you'll want to use itemfactoryconnector classes :)

(anyway, I found inconsistency in itemfactory - why do we have
  Gtk_Widget& create_item(const string & path,
                          const _gtk_string & accelerator,
                          const string & item_type, void (*target_func)());
and
  template <class RECEIVER, class ARG_TYPE>
  Gtk_Widget& create_item(const string &path,
                          const _gtk_string &accelerator,
                          const string &item_type,
                          RECEIVER *target_widget,
                          void (RECEIVER::*target_method)(ARG_TYPE),
                          ARG_TYPE target_method_arg);
I mean the template version has extra arg given, but there's no version
where extra arg is not given and the other create_item does not have
possibility to add extra arg at all :)

)
> d_menuFactory = new Gtk_ItemFactory_MenuBar("<Main>");
> d_menuFactory->create_items (nmenu_items, menu_items, 0);
>   {  // ugly
>   Gtk_ObjectHandle<Gtk_MenuBar> a(d_menuFactory->get_menubar_widget(""));
>   d_menuBar = a;
>   }

why not keep d_menuBar as Gtk_ObjectHandle<Gtk_MenuBar>, instead of
Gtk_MenuBar*?

> d_vbox.pack_start (*d_menuBar, FALSE, FALSE, 0);
> d_menuBar->show ();

> This works, but I can't figure out how to add the callback info to the
> menu_items definition. I've tried a c-style functions (as in the old code
> above), a C++ style method but keep getting compile errors or
> just non-working code. So after more than an hour of putzing around
> I gave up.

Note that the types of the methods needs to be correct...

-- 
-- Tero Pulkkinen -- terop@modeemi.cs.tut.fi --