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

[Peter Hutterer]

On Tue, Nov 17, 2015 at 06:09:17PM +0800, Jonas Ådahl wrote:
> The wp_relative_pointer interface is an extension to the wl_pointer
> interface created from wl_seat. It has the same focus, but adds the
> functionality of sending relative pointer motions unhindered by
> constraints such as monitor edges or other barriers. It also contains
> unaccelerated pointer motion information.
> 
> Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
> ---
> 
> There has alreay been RBs on this protocol, but I'd like to get them
> explicitly re-RB:ed considering that the protocol has changed some, even
> though the changes have not been major ones.
> 
> 
> Changes since the last version sent as weston patches:
> 
> Interfaces and protocol renamed according to wayland-protocols naming
> conventions.
> 
> Accelerated and unaccelerated motion deltas have the data type
> wl_fixed_t now again. 64 bit fixed point deltas was deemed unnecessary,
> and wl_double_fixed_t was dropped.
> 
> 64 bit timestamp argument name suffix changed from msb/lsb to hi/lo.
> 
> Various other minor changes.
> 
> 
> Jonas
> 
> 
>  Makefile.am                                        |   1 +
>  unstable/relative-pointer/README                   |   4 +
>  .../relative-pointer-unstable-v1.xml               | 122 +++++++++++++++++++++
>  3 files changed, 127 insertions(+)
>  create mode 100644 unstable/relative-pointer/README
>  create mode 100644 unstable/relative-pointer/relative-pointer-unstable-v1.xml
> 
> diff --git a/Makefile.am b/Makefile.am
> index f1bac16..2db6bd5 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -5,6 +5,7 @@ nobase_dist_pkgdata_DATA =							\
>  	unstable/text-input/text-input-unstable-v1.xml				\
>  	unstable/input-method/input-method-unstable-v1.xml			\
>  	unstable/xdg-shell/xdg-shell-unstable-v5.xml				\
> +	unstable/relative-pointer/relative-pointer-unstable-v1.xml		\
>  	$(NULL)
>  
>  pkgconfigdir = $(libdir)/pkgconfig
> diff --git a/unstable/relative-pointer/README b/unstable/relative-pointer/README
> new file mode 100644
> index 0000000..64c42a1
> --- /dev/null
> +++ b/unstable/relative-pointer/README
> @@ -0,0 +1,4 @@
> +Relative pointer protocol
> +
> +Maintainers:
> +Jonas Ådahl <jadahl at gmail.com>
> diff --git a/unstable/relative-pointer/relative-pointer-unstable-v1.xml b/unstable/relative-pointer/relative-pointer-unstable-v1.xml
> new file mode 100644
> index 0000000..0411d1f
> --- /dev/null
> +++ b/unstable/relative-pointer/relative-pointer-unstable-v1.xml
> @@ -0,0 +1,122 @@
> +<?xml version="1.0" encoding="UTF-8"?>
> +<protocol name="relative_pointer_unstable_v1">

It'd be nice to use <description> here to add a high-level overview of the
protocol, this is the best place to add prose to put people in the right
mindset :)

> +
> +  <copyright>
> +    Copyright © 2014      Jonas Ådahl
> +    Copyright © 2015      Red Hat Inc.
> +
> +    Permission is hereby granted, free of charge, to any person obtaining a
> +    copy of this software and associated documentation files (the "Software"),
> +    to deal in the Software without restriction, including without limitation
> +    the rights to use, copy, modify, merge, publish, distribute, sublicense,
> +    and/or sell copies of the Software, and to permit persons to whom the
> +    Software is furnished to do so, subject to the following conditions:
> +
> +    The above copyright notice and this permission notice (including the next
> +    paragraph) shall be included in all copies or substantial portions of the
> +    Software.
> +
> +    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> +    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> +    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> +    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> +    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> +    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> +    DEALINGS IN THE SOFTWARE.
> +  </copyright>
> +
> +  <interface name="zwp_relative_pointer_manager_v1" version="1">
> +    <description summary="get relative pointer objects">
> +      A global interface used for getting the relative pointer object for a
> +      given seat.
> +
> +      Warning! The protocol described in this file is experimental and backward
> +      incompatible changes may be made. Backward compatible changes may be added
> +      together with the corresponding interface version bump.  Backward
> +      incompatible changes are done by bumping the version number in the
> +      protocol and interface names and resetting the interface version.  Once
> +      the protocol is to be declared stable, the 'z' prefix and the version
> +      number in the protocol and interface names are removed and the interface
> +      version number is reset.
> +    </description>
> +
> +    <request name="destroy" type="destructor">
> +      <description summary="destroy the relative pointer manager object">
> +	Used by the client to notify the server that it will no longer use this
> +	relative pointer manager object.
> +      </description>
> +    </request>
> +
> +    <request name="get_relative_pointer">
> +      <description summary="get a relative pointer object">
> +	Create a relative pointer interface given a wl_pointer object. See the
> +	wp_relative_pointer interface for more details.
> +      </description>
> +
> +      <arg name="id" type="new_id" interface="zwp_relative_pointer_v1"/>
> +      <arg name="pointer" type="object" interface="wl_pointer"/>
> +    </request>
> +  </interface>
> +
> +  <interface name="zwp_relative_pointer_v1" version="1">
> +    <description summary="relative pointer object">
> +      A wp_relative_pointer object is an extension to the wl_pointer interface
> +      used for emitting relative pointer events. It shares the same focus as
> +      wl_pointer objects of the same seat and will only emit events when it has
> +      focus.
> +    </description>
> +
> +    <request name="destroy" type="destructor">
> +      <description summary="release the relative pointer object"/>
> +    </request>
> +

Should we add something about pairing this with wl_seat capabilities here?
Just looking at this protocol doesn't make it clear what happens if the
compositor drops the wl_pointer. Right now it's implicit, when the
capability drops you need to destroy the wl_pointer and the
wl_relative_pointer; spelling this out is useful.

either way Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>

Cheers,
   Peter

> +    <event name="relative_motion">
> +      <description summary="relative pointer motion">
> +	Relative x/y pointer motion from the pointer of the seat associated with
> +	this object.
> +
> +	A relative motion is in the same dimension as regular wl_pointer motion
> +	events, except they do not represent an absolute position. For example,
> +	moving a pointer from (x, y) to (x', y') would have the equivalent
> +	relative motion (x' - x, y' - y). If a pointer motion caused the
> +	absolute pointer position to be clipped by for example the edge of the
> +	monitor, the relative motion is unaffected by the clipping and will
> +	represent the unclipped motion.
> +
> +	This event also contains non-accelerated motion deltas. The
> +	non-accelerated delta is, when applicable, the regular pointer motion
> +	delta as it was before having applied motion acceleration and other
> +	transformations such as normalization.
> +
> +	Note that the non-accelerated delta does not represent 'raw' events as
> +	they were read from some device. Pointer motion acceleration is device-
> +	and configuration-specific and non-accelerated deltas and accelerated
> +	deltas may have the same value on some devices.


> +
> +	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"/>
> +      <arg name="dx" type="fixed"
> +	   summary="the x component of the motion vector"/>
> +      <arg name="dy" type="fixed"
> +	   summary="the y component of the motion vector"/>
> +      <arg name="dx_unaccel" type="fixed"
> +	   summary="the x component of the unaccelerated motion vector"/>
> +      <arg name="dy_unaccel" type="fixed"
> +	   summary="the y component of the unaccelerated motion vector"/>
> +    </event>
> +  </interface>
> +
> +</protocol>
> -- 
> 2.4.3