Apple Inc.
Application programming interface for gesture operations

Abstract:

At least certain embodiments of the present disclosure include an environment with user interface software interacting with a software application to provide gesture operations for a display of a device. A method for operating through an application programming interface (API) in this environment includes transferring, from platform code configured to provide a common framework for handling gesture events, to a program, a rotation transform function call in response to an input that corresponds to a gesture based on two or more concurrent touches. The method includes transferring, via the API, a gesture change function call from the platform code to the program in response to detecting a change in the gesture that corresponds to a change in one or more touches. The method includes, in response to transferring the rotation transform function call and the gesture change function call, performing a rotation transform to rotate a view of the program.