[PATCH wayland-protocols 1/2] Introduce wp_relative_pointer interface

[Jonas Ådahl]

On Mon, Jan 04, 2016 at 02:09:16PM +1000, Peter Hutterer wrote:
> On Fri, Jan 01, 2016 at 04:00:33PM +0000, Daniel Stone wrote:
> > Hi Jonas,
> > 
> > On 17 November 2015 at 10:09, Jonas Ådahl <jadahl at gmail.com> wrote:
> > > +    <event name="relative_motion">
> > > +      <description summary="relative pointer motion">
> > > +       [...]
> > > +
> > > +       Relative motions are not coupled to wl_pointer.motion events, and can be
> > > +       sent in combination with such events, but also independently. There may
> > > +       also be scenarious where wl_pointer.motion is sent, but there is no
> > > +       relative motion. The order of an absolute and relative motion event
> > > +       originating from the same physical motion is not guaranteed.
> > > +
> > > +       If the client needs button events or focus state, it can receive them
> > > +       from a wl_pointer object of the same seat that the wp_relative_pointer
> > > +       object is associated with.
> > > +      </description>
> > > +
> > > +      <arg name="utime_hi" type="uint"
> > > +          summary="high 32 bits of a 64 bit timestamp with microsecond granularity"/>
> > > +      <arg name="utime_lo" type="uint"
> > > +          summary="low 32 bits of a 64 bit timestamp with microsecond granularity"/>
> > 
> > My only concern with this is that, as Peter said, it could be
> > potentially difficult to correlate the two event streams
> > (wl_relative_pointer::motion vs. wl_pointer::button) with different
> > time units, unless we specify rounding.
> 
> This should be solved if we send them in the same wl_pointer.frame, right?

Yes. I think we should just wait until the wayland release including
.frame and just add then a blurb about that here somewhere.


Jonas

> 
> Cheers,
>    Peter