How to know if a NSWindow is fullscreen in Mac OS X Lion?
I guess I should check if [NSApplication presentationOptions] contains NSFullScreenModeApplicationPresentationOptions , but how do I achieve that? EDIT: using [NSApplication presentationOptions] doesn't work as in my document-based app there might be some documents in fullscreen and others not. I'm now looking for another solution. I'm wondering why there isn't a property called [NSWindow isFullscreen] or something like that. I was just looking for a solution myself and based on Matthieu's answer I created a category on NSWindow that works fine for me. @interface NSWindow (FullScreen) - (BOOL