I don't really know what it is but the icon on the top right of a finder window, (oval shaped button) when clicked hides the sidebar and toolbar icons, how can I implement something like this in my XCode project?
Thanks
As far as I can tell, this is just a standard NSButton that has a particular action bound to it. Adium has a similar button and is open source, you might try reading through the source code to see what they've done.