[PATCH weston 00/14] Desktop Protocol Support for IVI-Shell

Quentin Glidic sardemff7+wayland at sardemff7.net
Tue Nov 7 17:58:22 UTC 2017

On 11/7/17 6:01 PM, Matt Hoosier wrote:
> Hi Pekka,
> On Wed, Oct 25, 2017 at 10:09 AM, Ucan, Emre (ADITG/ESB) 
> <eucan at de.adit-jv.com> wrote:
>> Actually,  IMO ivi-shell is not a proper wayland compositor.
>> Because it is violating wayland protocol by not supporting wl_shell
>> interface.

The wl_shell protocol was designed for the desktop use case. So not 
supporting it is perfectly fine on non-desktop.

>> Therefore, we have to at least support wl_shell interface in
>> ivi-shell. Why not support it via libweston-desktop ?
> I'm wondering if you have any thoughts on this one specific point
> that Emre made. I know there's a lot of heartburn over the inclusion
> of wl_shell into the core protocol, and you wouldn't do it that way
> if that decision were getting made today.
> But given the history that actually happened, is there a reason not
> to go ahead and allow the ivi-shell to implement wl_shell simply on
> the grounds that it is part of the defined core protocol? I think
> that some potentially reasonable answers were made above to your
> concerns that the API offered by wl_shell targeted toward desktops
> wouldn't be meaningful on an IVI system.  All the mandatory
> operations seem to be possible to support,

Except the current patch doesn’t say that. xdg_shell allows the 
compositor to ignore the fullscreen/maximize requests. libweston-desktop 
API was designed around xdg_shell, with best effort for wl_shell (and I 
am in the process of fixing that). With wl_shell, the compositor cannot 
deny the client the fullscreen or maximized state.

> and the IVI shell just needs to come up with sensible definitions
> (i.e., documented for its users) about how the anonymous wl_shell
> clients' surfaces will be integrated with the explicit IVI clients.
> Note, I'm not for the moment trying to expand this line of reasoning 
> into a grounds for justifying the support of xdg-shell. That
> protocol is (deliberately) not part of the core, and I understand
> that. If a magic wand were to be waved and use of libweston-desktop
> didn't automatically mean that xdg-shell is supported too, would that
> be tolerable?

xdg_shell was not added to core to avoid the wl_shell situation. We 
cannot drop wl_shell support because it’s in core wayland.xml, and it’s 
hurting us already, because wl_shell clients will always prevent a full 
migration to xdg_shell. We are lucky that libweston-desktop (and others) 
doesn’t need too much code to support it.



Quentin “Sardem FF7” Glidic

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