Changes

Touch screen events cause one of four methods on the first responder object to be called. The method that gets called for a specific event will depend on the nature of the interaction. In order to handle events, therefore, it is important to ensure that the appropriate methods from those outlined below are implemented within your responder chain. These methods will be used in the worked example contained in the [[An Example Swift iOS 8 Touch, Multitouch and Tap Application|An Example iOS 10 Touch, Multitouch and Tap Application]] and [[Detecting iOS 8 Touch Screen Gesture Motionsin Swift|Detecting iOS 10 Touch Screen Gesture Motions]] chapters of this book.

When a gesture is interrupted due to a high level interrupt, such as the phone detecting an incoming call, the touchesCancelled method is called.