Comment 21 for bug 365952

(In reply to comment #16)
>
> the scenario I was thinking of is that you move into the right bottom corner,
> then along in the blacklisted area to the left bottom corner and then up into
> the allowed area. This would generate a jump the length of the touchpad's
> width.
>
> We can work around that though. Since by default the touchpad is in relative
> mode anyway, the only thing that should be capped here are the actual posts of
> the motion event, not the internal state. So at any point in time, the movement
> history contains the actual values - including the blacklisted area.
>
> For your patch, this means that you hook in before posting the event and reset
> dx/dy to zero for blacklisted areas. I think that should do the job.
>
> If the finger triggers an edge, no motion event is posted (i.e. the edges form
> the blacklisted area).
>

Ok, I see what you mean now.

I think I can start working on a prototype now.