If you press cmd+shift+4 in Mac OS X you are able to select an area on your screen with the corrosponding coordinates shown. I need to implement such a function in one of my applications and have no idea of how to do it. Could anyone give me some advices on that?
Thx.
Typically this is done with an translucent overlay window which covers the entire desktop space.
Apple's got some older sample code which should give you a start.