How to implement OSD overlay in Wayland/Weston

[Simon Ser]

On Tuesday, November 19, 2019 1:08 PM, Pekka Paalanen <ppaalanen at gmail.com> wrote:

> On Tue, 19 Nov 2019 12:55:31 +0100
> Guillermo Rodriguez guillerodriguez.dev at gmail.com wrote:
>
> > Hi,
> > El mar., 19 nov. 2019 a las 12:38, Sebastian Krzyszkowiak
> > (dos at dosowisko.net) escribió:
> >
> > > On 11/19/19, Pekka Paalanen ppaalanen at gmail.com wrote:
> > >
> > > > yes. I'm not aware of any Wayland extension that would allow clients to
> > > > dictate always-on-top behaviour on the desktop. It has an obvious
> > > > attack vector (malicious or misbehaving app setting always-on-top
> > > > without user's consent) and a simple corner case (how do you stack
> > > > multiple always-on-top windows).
> > > > OSD as a concept seems like a desktop component, not a normal app.
> > > > Hence I would expect such a client to use a domain-specific or custom
> > > > protocol extension to set always-on-top. If your use case is not a
> > > > generic desktop but some special environment, then a domain-specific
> > > > protocol extension would be a way to go. For generic desktop
> > > > environments you'd integrate with the particular DE specifically, e.g.
> > > > a gnome-shell plugin or something.
> > > > That is, if the OSD really is an independent separate program and not a
> > > > part of some fullscreen application.
> > >
> > > Sounds like something layer-shell protocol solves portably already.
> >
> > That sounds interesting. Is that supported by Weston?
>
> No. Not yet at least.

layer-shell's goal is to provide a way to create portable desktop
components, so it indeed seems like it's a nice fit for this use-case.
Note that for security reasons access to layer-shell could be
restricted, so layer-shell shouldn't be used by regular clients.

Regarding Weston support, there's [1] which seems to implement part of
layer-shell. I don't know how up-to-date and complete it is.

[1]: https://github.com/myfreeweb/weston-extra-dip