PendingBegin flag on XI_TouchMotionUnowned events?

Chase Douglas chase.douglas at
Tue Jan 25 09:11:44 PST 2011

On 01/25/2011 04:58 AM, Daniel Stone wrote:
> On Tue, Jan 25, 2011 at 11:35:37AM +1000, Peter Hutterer wrote:
>> On Mon, Jan 24, 2011 at 12:25:25PM -0500, Chase Douglas wrote:
>>> We currently have a mechanism for clients selecting for unowned events
>>> to receive motion and finish events (through the PendingFinish flag).
>>> However, how does a non-owner know that a TouchBegin event isn't owned
>>> yet? Should we mutate TouchBegin events to TouchMotionUnowned and set a
>>> PendingBegin flag?
>> why not set the owner flag on the TouchBegin event?
> Actually, I was just going to send a TouchOwnership event straight after
> TouchBegin, to make life simpler for clients.  So, TouchBegin means
> 'you will get events for this touch at some stage', and TouchOwnership
> means 'you're now the owner, go nuts', always.

Ok, it was this part that I didn't understand when I made my changes to
the server.

However, I'm not sure I like where this is going. It means that clients
will receive TouchBegin and TouchEnd events for touches they never
became owners of, even if they didn't want to receive unowned events. I
would prefer a protocol where most clients, who will not want unowned
events, do not receive any events until they are the owner. This will
prevent unnecessary wakeups of processes during gesture recognition, for

I have some ideas on how to accomplish this, but I've run out of time
before my next flight...


-- Chase

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