multi-touch-dev team mailing list archive

[Chase Douglas <chase.douglas@xxxxxxxxxxxxx>]

On Fri, 2010-10-08 at 11:08 -0700, James wrote:
> On 10/08/2010 08:10 AM, Chase Douglas wrote:
> > The sticky point comes when we need to handle the possibility for both
> > gestures and low-latency multitouch input. For example, think of the
> > three finger hold to unlock many finger MT and gestures occurring over a
> > paint application. With the proposed XI 2.1 passive grabbing paradigm,
> > gimp will receive tentative events and may start painting, knowing that
> > it will need to undo those paints if the events should be discarded.
> > This should occur as immediately as possible after touches hit the
> > screen.
> I assume that an application would have to explicitly request tentative 
> touch events, correct?

Any application/toolkit that uses XI 2.1 would receive these tentative
touch events, if another client is passively grabbing the events. It's
assumed that if they are coded for XI 2.1 that they know what they are
doing. An application/toolkit is still free to use X core, XI 1, and XI
2 with the grab semantics as currently specified.

> Is there a version/patches to the XInput2.1 proposals that talks about 
> the tentative events?  Have the semantics of how the "throw those events 
> away" might work been discussed?

Not quite yet. I am about to test out the patches Daniel Stone pushed
out to xorg-devel, having compilation issues :). They don't include the
simultaneous delivery to grabbing and non-grabbing clients yet. I
briefly discussed this with Daniel, and he thought this wouldn't be too
difficult to implement, but it was just a gut reaction.

-- Chase