title: How to know if a NSWindow is fullscreen in Mac OS X Lion?
body: <p>I guess I should check if <code>[NSApplication presentationOptions]</code> contains <code>NSFullScreenModeApplicationPresentationOptions</code>, but how do I achieve that?</p>
  
  <p>EDIT: using <code>[NSApplication presentationOptions]</code> 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 <code>[NSWindow isFullscreen]</code> or something like that.</p>