UITouch object represents the location, size, movement, and force of a finger on the screen for a particular event. The
force of a touch is available starting in iOS 9 on devices that support 3D Touch or Apple Pencil.
- iOS 2.0+
- tvOS 2.0+
You access touch objects through
UIEvent objects passed into responder objects for event handling. A touch object includes accessors for:
The view or window in which the touch occurred
The location of the touch within the view or window
The approximate radius of the touch
The force of the touch (on devices that support 3D Touch or Apple Pencil)
A touch object also contains a timestamp indicating when the touch occurred, an integer representing the number of times the user tapped the screen, and the phase of the touch in the form of a constant that describes whether the touch began, moved, or ended, or whether the system canceled the touch.
A touch object persists throughout a multi-touch sequence. Never retain a touch object when handling an event. If you need to keep information about a touch from one touch phase to another, copy that information from the touch.