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.
- iOS 8.0+
- tvOS 9.0+
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