[PATCH inputproto multitouch] Touch IDs must be at least unique per master device

Daniel Stone daniel at fooishbar.org
Sun Dec 11 11:41:16 PST 2011


On 9 December 2011 21:43, Chase Douglas <chase.douglas at canonical.com> wrote:
> XIAllowEvents with a master device and a touch ID must uniquely identify
> a touch sequence. If touch IDs were unique per slave device, multiple
> slave devices could have valid sequences with the same touch ID, and the
> sequences may both be grabbed through the same master device grab.

FWIW, this was deliberate, to avoid having to either keep a shared
allocation space for touch IDs, or to have differing touch IDs between
MD and SD delivery.  The idea was that the client should maintain a
sourceid:touchid tuple, rather than deviceid:touchid.

I'm completely ambivalent on this change though, I don't think it
makes any odds really.


More information about the xorg-devel mailing list