On 10/08/2010 03:32 PM, Chase Douglas wrote: [...] >> In the sense that a multi-finger drag never terminates, this is true. By not >> listening to the drag gestures, the MT events can be let through to the >> client. > > I'm beginning to think we need a separate gesture primitive: touch. For > example, take the Unity window movement gesture (note this is different > than what's been published in the original UI docs, it changed near > release). The user initiates the gesture with three fingers, but must > remove a finger to enter window movement mode. We don't currently have a > good primitive for this, the closest thing we can do is subscribe to all > three finger gesture events so that we pick up the three finger touch.
Interesting idea, let me think about that a bit. > If we add a gesture primitive called "touch" that is active any time the > accompanying number of fingers is touching the screen, then we can use > it for state transitions like above and add the timeouts for initiation > to all the current gesture types. I do not think we want to commit so deeply to a certain gesture policy. These problems really seem to arise because we want to resolve a global problem (gestures) using a local solution (touch grabs). Any other suggestions out there? >>> I think the proper grab semantics for the purposes of system-wide >>> gestures is for the WM to have a passive grab on MT devices. This grab >>> would be activated when a touch begins, and deactivated when a touch >>> ends. However, each grab would be per-touch, and the WM could choose to >>> "replay" events for any given touch to other clients. Replaying events >>> essentially means the client relinquishes the grab for that touch, and >>> all further events from that touch will not be grabbed as well. >> >> >> The passive grab notion fits well into reformulating what we can do today, >> but >> it still leaves more to wish for in terms of touches outside of the window. >> Imagine the situation where you have the index finger down on a substrate, >> moving it around, reading a map. Now you want to zoom out, so you put down >> the >> thumb to pinch. The thumb finger is outside the window at first, then moved >> inside as it approaches the index finger. This feels like a very natural >> gesture >> to me, but it does not fit into our current thinking of passive grabs. > > I understand what you are going for, but I worry about ambiguity. The > second touch that occurs outside the window might be intended for a > different window. Maybe it's a different user altogether? Here is a question for you: is the division of touches into logical groups, like hands, a context-dependent problem? > I wonder how often one would need to zoom like this, and not have the > area to do so with the current method? Do you have any examples where > this zooming paradigm is necessary? Necessity is more or less defined by what we do here, so I believe the question tries to avoid the problem. :-) > Aside from necessity, I'm not sure how intuitive this zooming paradigm > would be, since most people are used to zooming in the current fashion > only. Maybe I'm wrong, but I've not used any UIs that allowed zooming as > you propose. Honestly, I have not yet seen a single touch interface that really utilizes multitouch. Cheers, Henrik _______________________________________________ Mailing list: https://launchpad.net/~multi-touch-dev Post to : multi-touch-dev@lists.launchpad.net Unsubscribe : https://launchpad.net/~multi-touch-dev More help : https://help.launchpad.net/ListHelp
