Erik Barzeski on Cocoa’s broken window title bar document proxy icons.
With a Carbon app, dragging the proxy icon is just like dragging a file icon from within the Finder itself. Dragging means move, Option-dragging means copy, Command-Option-dragging means make an alias. With the default Cocoa behavior, there is no way to simply move the original file itself: dragging means make an alias, and Option- or Command-dragging means make a copy. The Carbon behavior, in addition to being far more useful, matches what’s prescribed by the HIG.
★ Saturday, 11 November 2006