iOS Developer Library


UIKit Framework Reference UICollisionBehaviorDelegate Protocol Reference

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To respond to UIKit dynamic item collisions, configure a custom class to adopt the UICollisionBehaviorDelegate protocol. Then, in a collision behavior (an instance of the UICollisionBehavior class), set the delegate to be an instance of your custom class.

The delegate is notified of collisions that occur between the behavior’s dynamic items, or between a dynamic item and a boundary, depending on the behavior’s mode (as set with its collisionMode property). In the case of a collision between an item and the boundary defined by a reference view, the identifier passed to the delegate method is nil. (For more on the reference view and the different ways to initialize a dynamic animator, read the Overview in UIDynamicAnimator Class Reference.)