NSViewFocusDidChangeNotification is deprecated since 10.4, and the docs say "Instead use NSViewBoundsDidChangeNotification and NSViewFrameDidChangeNotification to get the same information provided by this notification." But doesn't that mean that I'd have to set up notifications not only on the view of interest, but on its superview, and its superview's superview, and all the way up the chain? Basically I want to be notified whenever the result of [myView convertRectToBacking:myView.bounds] might change.