"A machine readable storage medium storing executable program instructions which when executed cause a data processing system to perform a method comprising:
receiving a user input, the user input is one or more input points applied to a touch-sensitive display that is integrated with the data processing system;
creating an event object in response to the user input;
determining whether the event object invokes a scroll or gesture operation by distinguishing between a single input point applied to the touch-sensitive display that is interpreted as the scroll operation and two or more input points applied to the touch-sensitive display that are interpreted as the gesture operation;
issuing at least one scroll or gesture call based on invoking the scroll or gesture operation;
responding to at least one scroll call, if issued, by scrolling a window having a view associated with the event object; and
responding to at least one gesture call, if issued, by scaling the view associated with the event object based on receiving the two or more input points in the form of the user input."
That is confused legalese for saying that if only one finger has moved on the screen, the program sends a scroll event for the displayed object, and if two or more fingers have moved, the program sends a scale, i.e. zoom, event for the said object.
That is, MOVE MORE THAN ONE FINGER --which includes PINCH/UNPINCH with thumb and index, which are the most likely fingers to move-- to ZOOM out/in.
It's actually more than pinch to zoom. If I write a program that uses any more than one finger to scale (zoom) an object, I'll be infringing.