[PATCH 3/3] Add a release request on wl_seat

[Derek Foreman]

On 25/02/15 08:03 AM, David FORT wrote:
> This is required if we want to correctly remove a wl_seat server-side.
> ---
>  protocol/wayland.xml | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/protocol/wayland.xml b/protocol/wayland.xml
> index 4fb8035..8f63ebf 100644
> --- a/protocol/wayland.xml
> +++ b/protocol/wayland.xml
> @@ -1400,6 +1400,12 @@
>        <arg name="name" type="string"/>
>      </event>
>  
> +    <!-- Version 3 additions -->
> +
> +    <request name="release" type="destructor" since="3">
> +      <description summary="release the seat object"/>
> +    </request>
> +

wl_seat appears to currently be version="4", so I guess we'd have to
bump the since= and the version in the comment... (and probably the
version of wl_seat as well)

Unfortunately, I don't think this is necessary or sufficient to solve
the problem at hand (RDP compositor connections are new seats, once apps
bind these seats they're essentially leaked forever even after RDP
client disconnect)

It's unnecessary because we already can remove seats once all clients
using them close (I don't feel this is realistic, though)

It's insufficient because we don't have a way to tell a client the seat
it currently has isn't going to provide any more input ever.

However, I think if we're ever going to kill this problem we'll need
this destructor, so if the version numbers are updated appropriately:

Reviewed-by: Derek Foreman <derekf at osg.samsung.com>

We'll still need a way to tell the client the seat it has is
dead/inert/whatever.  I don't think we can rely on the existing
capabilities being empty, since with libinput backed seats it may be
worthwhile for a toolkit/app to keep those seats to retain state in case
the devices are plugged back in.

That is, there's a difference between a disconnected RDP client and a
libinput backed seat with no devices left in it.

Would a new seat event (say, "removed") solve this sufficiently?

>    </interface>
>  
>    <interface name="wl_pointer" version="3">
>