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

[Daniel Stone]

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.

Cheers,
Daniel