Moving CALayer's mask on scroll in a Scrollview

Question

I am experimenting with iOS SDK and I have the following UIView structure:

• UIView
  • UIImageView - only a background i

Answer 1

CALayer are implicit animated for some properties like position try to disable them:

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{

[CATransaction begin];
    [CATransaction setValue:(id)kCFBooleanTrue forKey:kCATransactionDisableActions];
CGPoint contentOffset = scrollView.contentOffset;
contentOffset.y = -contentOffset.y;

self.overlayImageView.viewlayer.mask.position = contentOffset;
[CATransaction commit];

}