IOS gestures-tap, touch, gesture

1. Concept

Gestures are all events that occur when you touch the screen with one or more fingers, until your finger leaves the screen. This gesture exists regardless of how long the gesture lasts, as long as one or more fingers remain on the screen.

Touch refers to the behavior of placing your finger on the screen of an iOS device, dragging or lifting it from the screen. The number of touches involved in a gesture equals the number of fingers that are simultaneously on the screen.

A gesture recognizer is an object that knows how to observe a user-generated stream of events and is able to identify when a user is touching and dragging in a manner that matches a predefined gesture. The Uigesturerecognizer class and its various seed classes can save a lot of effort when detecting common gestures. The Uigesturerecognizer class encapsulates the functionality of the find gesture nicely and is easily applied to any view .

2. Responder Chain

Because gestures are passed to the system within an event, events are passed through the responder chain responder chain.

In one application, the responder chain is a mutable collection of objects capable of responding to user events.

IOS gestures-tap, touch, gesture