I don’t think you should unconditionally declare this one:

+- (void)windowDidEnterFullScreen:(NSNotification *)notification;

Only declare it for the 10.6 build, please.

Ah, yes, that seems correct. It is provided from 10.7 onwards.
 
Alternatively, we can implement a non-notification variant of windowDidBecomeKey (it doesn't use the notification anyway), that way we can move the code from windowDidEnterFullScreen from the notification variant to the non-notification variant, and avoid a lot of the notification complexity.

    -- Anders