I used this guide: http://developer.apple.com/mac/library/qa/qa2004/qa1346.html to implement scaling in a special view. The scaled view is the document view of an NSScrollView. The problem is that when I call -scaleUnitSquareToSize, then call -setNeedsDisplay:YES (I also tried -setNeedsDisplay:YES on the scroll view), the view (not the scroll bars, just everything inside) becomes blank. If I resize the window that contains the view, its contents reappear and display properly. But as soon as I rescale and redraw, it blanks out again. Any ideas on how to force the view to refresh properly?
Also, sorry for not providing source code, but the code is trade secret, so...