#GtkApplicationWindow is a #GtkWindow subclass that offers some extra functionality for better integration with #GtkApplication features. Notably, it can handle both the application menu as well as the menubar. See gtk.application.Application.setAppMenu and gtk.application.Application.setMenubar.
Fluent builder for gtk.application_window.ApplicationWindow
Fluent builder implementation template for gtk.application_window.ApplicationWindow
Module for ApplicationWindow class