截断清晰的子视图

Question

In iOS 8, FaceTime has a UITableView with a UIVisualEffectView behind it blurring the live camera feed. When you swipe against a cell, the cell moves to wipe in the Delete button, but it doesn't show fully behind the UITableViewCell.

My question is, is there an easy way to replicate this kind of behavior with normal subviews? ie have a clear CALayer clip an opaque CALayer with the clear CALayer not showing the subviews of its containing UIView. I assume what I'm going for is a "Wipe" transition.

I'm pretty new to using CALayers and drawRect: and would love some direction in starting.

Answer 1

To answer my own question, you have you use a CALayer and store it in the backgroundView's layer.mask property. Then animate the position and bounds of this mask layer and voila.