It is most likely a combination of the touch APIs and hardware. Android has gone from no official multi-touch (1.5-1.6), multi-touch with indistinguishable points (2.0, 2.1) to multiple distinguishable points in 2.2, but I would be ensure as to how good the code is, although it does officially support up to 256 points I think.
You'll have to do some extra event processing to get around this as best you can. 1) Take a look at Luke Hutch's MultiTouchController for a good idea of how to do event filtering well. 2) Apply your own extra logic. Consider the following example: 1) A user places down their first finger, followed by their second finger and then their third. Android will give you pointer ids for these, record them but also assign your own id to each finger (e.g. 1, 2, 3 in the order you got them) 2) The user drags in a line across the screen (something like finger painting) and lifts their middle finger half way in the drag. Android will give you a pointer up event with the pointer ID it thinks went up, let's call this X. Record this and the fact a finger went up, but don't respond to the event just yet. 3) Wait till you receive the next touch event and take a look at the x,y coordinates of the points. If, for example, the value of X in step 2 that Android gave you made you think the user had lifted their third finger (although they actually lifted their middle one) then you can check if this is correct: it will appear that the position of the middle finger (according to your ID system) has jumped to somewhere near where the third one is. That is only a brief example to demonstrate - but essentially based on event history you need to determine how probable the current event you receive is, and if it's unlikely figure out what you think happened instead. I'd start off small, get 4 fingers working well first, then try moving up. On Jul 20, 5:08 am, J_kim <[email protected]> wrote: > Hi, all: > We have touch panels for 10.1 inches that support up to ten > fingers and set it on EeePC. We use Android 2.2 SDK to develop a > drawer to show 10 fingers' gesture. But there are some problems > about different finger's id. If we leave fingers in differnet > order, the 2.2 SDK can't decide the right order and pass the wrong > leave event for the drawer. We also can find those problems on > "DevTools > => Pointer Location" application. Please refer to the following > link:http://www.youtube.com/watch?v=ZFPnjAyZqyo > > Anyone has the same problem with us? Or it's the problem on our > hardware? > Thanks. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
