al_set_display_menu man page
al_set_display_menu — Allegro 5 API
#include <allegro5/allegro_native_dialog.h> bool al_set_display_menu(ALLEGRO_DISPLAY *display, ALLEGRO_MENU *menu)
menu with the
display and shows it. If there was a previous menu associated with the display, it will be destroyed. If you don't want that to happen, you should first remove the menu with al_remove_display_menu(3).
If the menu is already attached to a display, it will not be attached to the new display. If
NULL, the current menu will still be destroyed.
Note: Attaching a menu may cause the window as available to your application to be resized! You should listen for a resize event, check how much space was lost, and resize the window accordingly if you want to maintain your window's prior size.
Returns true if successful.