Protocol

CAAction

An interface that allows objects to respond to actions triggered by a CALayer change.

Declaration

@protocol CAAction

Overview

When queried with an action identifier (a key path, an external action name, or a predefined action identifier) a layer returns the appropriate action object–which must implement the CAAction protocol–and sends it a runActionForKey:object:arguments: message.

Topics

Responding to an action

- runActionForKey:object:arguments:

Called to trigger the action specified by the identifier.

Required.

Relationships

Conforming Types

See Also

Layer Basics

CALayer

An object that manages image-based content and allows you to perform animations on that content.

CALayerDelegate

Methods your app can implement to respond to layer-related events.

CAConstraint

A representation of a single layout constraint between two layers.

CALayoutManager

Methods that allow an object to manage the layout of a layer and its sublayers.

CAConstraintLayoutManager

An object that provides a constraint-based layout manager.