Methods your app can implement to respond to layer-related events.
- iOS 10.0+
- macOS 10.12+
- UIKit for Mac 13.0+Beta
- tvOS 10.0+
- Core Animation
You can implement the methods of this protocol to provide the layer’s content, handle the layout of sublayers, and provide custom animation actions to perform. The object that implements this protocol must be assigned to the
delegate property of the layer object.