> > > PS: To be efficient, one should probably prevent the 'pointerdown' event to bubble to the ancestors of the map, because any gesture at an higher level than the map should never be triggered once the drag gesture did start. > > > > That will be event worse. I could easily imagine lots of behaviors that dwell on the same events and do not conflict - the drag/click/multitouch example is the simplest one. > > Not once the drag behavior did start. Once you start dragging, you don't want any other gesture to happen using the pointers currently consumed by the drag behavior. Not really. There are more responses an author might make to an event than check it for a gesture. I sometimes add an event handler on the document that adds visible "finger" markers to the document that track all of the touches. This is useful when demonstrating a multi-touch web page on a projector. Other things developers might do: maintain a list of active pointers (I believe such an example has been presented in this thread) ; temporarily disable text selection depending on where the pointer event occurred ; re-enable text selection when the pointerup occurs ; etc. If the "standard advice" is to stop pointer event bubbling when you recognize a gesture, then these sorts of things become impossible. Stopping bubbling should be rare.
Received on Tuesday, 9 April 2013 12:48:59 UTC