Squall Hierarchy Class Hierarchy CALayer SLAnimation SLCoreAnimation SLSquallAnimation SLLayer SLShapeLayer SLTextLayer SLShapePathLayer CATransformLayer SLTransformLayer NSObject SLAnimationInformation SLLivePreview SLProperty SLReader Squall Protocol References SLCoreAnimationBuildDelegate SLLayerProtocol SLLivePreviewDelegate Constant References SLAnimationEvent SLAnimationState SLPlaybackType SLSizing