Mouse outside layout

I've noticed runtimes keep focus on the mouse even if its not within the window, so I'd like to suggest a mouse/keyboard condition like mouse is outside layout.

I know you could probably add a detection object to follow mouse, but that seems like a wasted effort.

Or perhaps even a system property like keep focus.

Conditions! Check if mouse X or Y is greater than right and bottom edge (layout size, such as 640x400) or if it is smaller than left and top edge (0). If the condition is met, you can execute an event to make the mouse enrage and swallow the user whole. Or simply keep focus on the edge where mouse left the layout and wait until it comes back into the game.

But I think an enraged mouse is fun.

Enraged?

sounds fun to me!