Re: [AD] native menus

[Jon R. <wo...@cc...>]

Can you make it so the menu can be hidden/shown programmatically? Maybe
it would only appear if the mouse was near it or something (just as an
option).

On 06/19/2011 02:42 PM, Matthew Leverton wrote:
> Attached is a sample implementation of native system menus for
> Windows. I put it in the native dialog addon and updated the
> native_file_chooser example. The API is functional, but not complete:
>
> ALLEGRO_MENU *al_create_menu(void);
> bool al_append_menu (ALLEGRO_MENU *parent, ALLEGRO_MENU *popup, char
> const *title, int id);
> void al_set_display_menu(ALLEGRO_DISPLAY *display, ALLEGRO_MENU *menu);
>
> Basic usage:
>
> ALLEGRO_MENU *menu = al_create_menu();
> ALLEGRO_MENU *file = al_create_menu();
> al_append_menu(file, NULL, "Open", OPEN_ID);
> al_append_menu(file, NULL, "Exit", EXIT_ID);
> al_append_menu(menu, file, "File", 0);
> al_set_display_menu(display, menu);
>
> A higher level function could take some sort of A4-like structure to
> make creating the menu less verbose.
>
> Events are sent via the display's event source:
>
> if (event.type == ALLEGRO_EVENT_MENU_CLICK && event.menu.id == EXIT_ID)
>
> Now to the dirty implementation details:
>
> 1) It requires hooking into the Allegro Windows message callback
> (window_callback). I just hacked on an extra callback as part of the
> ALLEGRO_DISPLAY_WIN structure that the native dialog addon uses.
> Obviously that's not a great solution. What about adding a public
> function like:
>
> al_win_add_message_callback( /* my callback function */ );
>
> That would add a callback that would be processed before Allegro's. If
> it returns TRUE, then Allegro does not process the event. Obviously a
> person could break things with this, but I don't see why that's our
> concern.
>
> 2) I added a "first class" ALLEGRO_MENU_EVENT, but I assume addons
> shouldn't do that.
>
> I was going to just create and emit a user event (I assume that's what
> the audio streams do), but I wanted to use the display's event source.
> The docs say "The event source must have been initialised with
> al_init_user_event_source." Does that mean I'm not allowed to emit a
> user event through the display's event source?
>
> 3) I don't know about OS X or GTK menus, but I assume they could use
> the same sort of API as above.
>
> --
> Matthew Leverton
>
>
> ------------------------------------------------------------------------------
> EditLive Enterprise is the world's most technically advanced content
> authoring tool. Experience the power of Track Changes, Inline Image
> Editing and ensure content is compliant with Accessibility Checking.
> http://p.sf.net/sfu/ephox-dev2dev