Sets or unsets the #GtkApplication associated with the window.
The application will be kept alive for at least as long as it has any windows
associated with it (see g_application_hold() for a way to keep it alive
without windows).
Normally, the connection between the application and the window will remain
until the window is destroyed, but you can explicitly remove it by setting
the @application to %NULL.
This is equivalent to calling gtk_application_remove_window() and/or
gtk_application_add_window() on the old/new applications as relevant.
Sets or unsets the #GtkApplication associated with the window.
The application will be kept alive for at least as long as it has any windows associated with it (see g_application_hold() for a way to keep it alive without windows).
Normally, the connection between the application and the window will remain until the window is destroyed, but you can explicitly remove it by setting the @application to %NULL.
This is equivalent to calling gtk_application_remove_window() and/or gtk_application_add_window() on the old/new applications as relevant.