How to make a smooth, rounded, volume-like OS X window with NSVisualEffectView?
Update for OS X El Capitan The hack I described in my original answer below is not needed on OS X El Capitan anymore. The NSVisualEffectView’s maskImage should work correctly there, if the NSWindow’s contentView is set to be the NSVisualEffectView (it’s not enough if it is a subview of the contentView). Here’s a sample … Read more