If the layout specifies whether to the toplevel should go fullscreen, the value pointed to by @fullscreen is set to %TRUE if it should go fullscreen, or %FALSE, if it should go unfullscreen.
location to store whether the toplevel should be fullscreen
whether the @layout specifies the fullscreen state for the toplevel
See Implementation
If the layout specifies whether to the toplevel should go fullscreen, the value pointed to by @fullscreen is set to %TRUE if it should go fullscreen, or %FALSE, if it should go unfullscreen.