CALayer, NSTextView and scaling

Question

In my app I want to provide text scaling in layer backed NSTextView like Apple's TextEdit. I use analogue of it's ScalingScrollView. Also I need to create some CALayer overlays on self.window.contentView. All is ok until I make [self.window.contentView setWantsLayer:YES].

Before [setWantsLayer:YES]

After [setWantsLayer:YES]

I haven't any ideas how to fix this problem.

Answer 1

I've been searching for the solution to the similar issue, too. Finally, I discovered that layer-backed views must be positioned on integral pixels and must not be positioned on subpixels.

E.g. if you dynamically calculate frame of layer-backed view

 NSMakeRect((self.frame.size.width - 350)/2, (self.frame.size.height - 150)/2, 350, 150)

you may encounter non-integral values, so you should do something like

 NSMakeRect(floor((self.frame.size.width - 350)/2), floor((self.frame.size.height - 150)/2), 350, 150)