Code review comment for lp:~oif-team/frame/semi-mt-add-touches

I'll split out the key code into a separate function.

I think I can set the number of semi-mt touches to 1 by watching BTN_TOOL_FINGER. I had forgotten about its usage being equivalent to BTN_TOOL_*TAP. Note that it's not really necessary, however, since the number of semi-mt touches has an effect only when there are three or more touches.

I'm not sure what the best resolution to the touch ids issue is. It's true that the current solution will choose a recently used touch id, but this shouldn't really be an issue because the utouch-frame "protocol" tells the client when the touch has ended, right? The real issue is that we will be trampling on top of the touch id range reported by the kernel, but there's no way around this without creating a separate tracking id implementation in utouch-frame.

We could choose an id that's half way around the ring if you consider the tracking ids as a circular ring buffer. This would still be ~2^15 touches away, so there's low likelyhood of a tracking id collision. Would that be alright with you?