Patent ID: 7782307

Claim:
A method of processing touch inputs of touch devices that touchdown and liftoff on or near a touch sensitive surface, the surface including an associated plurality of touch sensors, the method comprising: reading data from the touch sensors to obtain positions of contacts corresponding to the touch devices on or near the surface wherein the data is read to enable simultaneous detection of multiple distinguishable contacts; tracking the contacts based on the positions; selecting an activity corresponding to an initial set of at least two of the contacts corresponding to at least two of the touch devices simultaneously on or near the surface, wherein the activity corresponds to one or more input events of a computing device; maintaining the selection of the activity when the number of contacts on or near the surface changes due to one or more touchdowns and liftoffs of touch devices, so long as at least one touch device remains touched down on or near the surface, wherein a second set includes a contact corresponding to each of the one or more remaining touch devices; determining a motion based on the tracking, wherein the motion is based on the initial set prior to the change in the number of contacts and is based on the second set after the change in the number of contacts; and based on the motion, generating at least one input event of the selected activity.