Event Registration and Dispatch System and Method for Multi-Point Controls
Dynamic registration of event handlers in a computer application or operating system recognizes multiple synchronous input streams by identifying each new stroke in a frame representing a single moment in time and mapping in a registration process each identified new stroke to a listening process that is associated with the user interface element to which the new input stream is to be applied. In the same frame, released strokes are unmapped and then each active listening process is called to carry out a respective control operation. When called, the strokes have the correct data for the given frame. The process is repeated for subsequent frames. By carrying out various processes in a sequence of frames, the concept of concurrency is preserved, which is particularly beneficial to multi-touch and multi-user systems.
1 - 8 . (canceled)
9 . A method of operating a multi-point input device, the method comprising:
displaying, on a graphical display surface of the multi-point input device, a plurality of interface elements;
in a first frame:
identifying a first hit of a new stroke A; and
registering the new stroke A to a first listener of at least one of the plurality of interface elements based on a positional relationship of a position of a contact of the new stroke A in the first frame and a tangible of the at least one of the plurality of interface elements, the first listener implementing a first control operation when the first listener is dispatched;
in a second frame subsequent to the first frame:
identifying a release of a registered stroke B registered to a second listener, the second listener implementing a second control operation when the second listener is dispatched;
unmapping the registered stroke B from the second listener, the second listener becoming an inactive listener that no longer listens to the registered stroke B; and
dispatching the first listener to implement the first control operation based on an updated state of the new stroke A, the updated state corresponding to a current position of a contact of the new stroke A in the second frame.
10 . The method of claim 9 , wherein a non-released stroke C is registered to the first listener.
11 . The method of claim 9 , wherein registering the new stroke A comprises registering the new stroke A to a registry.
12 . The method of claim 9 , wherein registering the new stroke A comprises mapping the new stroke A to the first listener.
13 . The method of claim 12 , wherein the plurality of interface elements have a hierarchical structure; and
wherein mapping the new stroke A to the first listener comprises ascertaining the at least one of the plurality of interface elements to which the new stroke A is applicable, the at least one of the plurality of interface elements being ascertained before another one of the plurality of interface elements as a result of the at least one of the plurality of interface elements being higher in the hierarchical structure than the other one of the plurality of interface elements.
14 . The method of claim 9 , wherein the new stroke A represents the first hit of the new stroke A by a first person in the first frame, the method further comprising identifying a second new stroke D representing a second hit of the second new stroke D by a second person in the first frame.
15 . The method of claim 9 , further comprising not dispatching the second listener to which the registered stroke B was registered.