multi-touch-dev team mailing list archive

[Chase Douglas <chase.douglas@xxxxxxxxxxxxx>]

On Wed, 2010-10-06 at 12:30 -0700, Ping Cheng wrote:
> On Wed, Oct 6, 2010 at 6:51 AM, Chase Douglas
> <chase.douglas@xxxxxxxxxxxxx> wrote:
> >
> > If I remember correctly, actively grabbed events cannot be replayed.
> > Only passively grabbed events. Since passively grabbed events must start
> > within a particular window, this scenario will never occur.
> >
> > I suggest reading the XI protocol specifications and the X core protocol
> > specification, where the semantics and details of input grabbing are
> > discussed:
> 
> Chase, you are right. I have messed up the master/core and
> passive/slave in my explanation. I need to get the terms and semantics
> right before I can comment more (that would take some time).
> 
> What I wanted to make clear was:
> 
> The spec and implementation need to
> 
> 1.   provide an easy way for toolkits/client to support the most
> popular/used MT features, such as basic gestures;
> 2.   leave rooms for sophisticated MT toolkits/apps/clients to grow.
> 
> For item 1, a smooth transition from XI (single touch events) to
> XI2.1, and vice versa, has to be carefully considered, with the
> posibility to turn XI or/and XI2.1 report/events off. Active and
> passive grabbing has to be tracked and probably managed. I am not
> exactly sure at which level though. I would think it is in X server?
> 
> For item 2, I would think those sophisticated MT apps will occupy the
> whole desktop, i.e., there is only one MT app running and all MT
> events can only reach that app. So, there would be no competition or
> inconsistence there.

These issues are what we are grappling with as we try to develop the
XInput 2.1 protocol. I think we're close to having a protocol that
works, and an implementation that is coming along as well. You can be
sure that our aim is to come up with something that works for all
application use cases.

-- Chase