How is it possible to create a “about” submenu under the menu on OSX?
just create a new menu item in the menubar somewhere. Set super class to ApplicationMenuItem and it will be relocated at runtime to the application menu.
That was fast,
Got it, thanks.
Okay but now how can I add an event-handler to the “about” menu item?
Add it to the app class.
You might want to also review the Menu section in User Guide Book 2, Chapter 2: Desktop.