Re: Fullscreen mode detection from background

FROM : Ken Thomases
DATE : Mon Apr 21 20:08:49 2008

On Apr 21, 2008, at 7:24 AM, Peter Hoerster wrote:
> is there a method to detect from the background if a foreground 
> program is running in fullscreen mode?
> I have to hide a floating panel when a video or game software is 
> running fullscreen.


It depends on what you mean by fullscreen mode.  Most programs which 
have a fullscreen mode capture the display(s) with CGDisplayCapture*
() or CGCaptureAllDisplays*().  If they do that, then I don't think 
you have to worry about it -- by design, the GUI of other 
applications won't display and they won't be informed of the change 
in display configuration.  (That's the point of capturing the 
display.  You don't want the Finder to rearrange all of your desktop 
icons when you change resolutions, for example.)

If by fullscreen mode you mean that the frontmost application has 
hidden the menubar and Dock via SetSystemUIMode, then you may need to 
monitor the mode by installing a Carbon event handler for the 
kEventAppSystemUIModeChanged event.  I assume, but can't be sure, 
that [NSMenu setMenuBarVisible:NO] uses SetSystemUIMode under the 
hood, and thus generates the same Carbon event.

Cheers,
Ken