+: enter-fullscreen ( world -- )
+ world-handle first NSScreen -> mainScreen f -> enterFullScreenMode:withOptions: drop ;
+
+: exit-fullscreen ( world -- )
+ world-handle first f -> exitFullScreenModeWithOptions: ;
+
+M: cocoa-ui-backend set-fullscreen? ( ? world -- )
+ swap [ enter-fullscreen ] [ exit-fullscreen ] if ;
+
+M: cocoa-ui-backend fullscreen? ( world -- ? )
+ world-handle first -> isInFullScreenMode zero? not ;
+