Mac OS X Lion: Detect if another application is running in full screen mode?

Question

In a Cocoa app, is there a way to tell if another application currently is in full screen mode?

My application is configured to show up on all Spaces and listens for

Answer 1

Hmm, have you ruled out using applescript/scriptingbridge? You can get the size of windows from applescript and compare them to the size of the screen. (or do you not know which screen a given app is on?)
Certain apps which are accessible will have an 'AXFullScreen' attribute on their windows. For example this works for some apps:

  tell application "System Events"
    tell process "Pages"
        repeat with myWin in windows
            get value of attribute "AXFullScreen" of myWin
        end repeat
    end tell 
end tell

The real action seems to be down in carbon... MacWindows.h and CarbonEvents.h have references to "FullScreen" in them.

You will need to research this though.