QtWayland decoration improvement

[Martin Flöser]

Am 2018-02-19 16:37, schrieb Martin Bříza:
> Hello everyone,
> 
> I thought this would be a good place to discuss this small problem:
> 
> I'm trying to make Qt work better under Wayland and especially in
> GNOME.  The current infrastructure in QtWayland doesn't allow for very
> complicated  window decorations. First, QWaylandAbstractDecoration is
> a private API  now, which is mostly fine, however I'd like to make it
> a bit better.  Especially, there's a problem with the limited
> possibilities we now have.  The decorations cannot have shadows and
> the ability to handle mouse events  is pretty limited.
> 
> I'd like to solve this systematically, for everyone, likely by
> patching  QtWayland to add new features to QWaylandAbstractDecoration
> and I'd like  to ask for your advice.
> 
> I know there is the KDecoration2 API which is feature-complete (and in
> my  opinion, it exposes a lot more stuff than what we would eventually
>  actually need in Qt). Could (partially or completely) upstreaming
> this  class help with this problem? There could be a base class in
> QtWayland  implementing the core functionality and KDecoration2 could
> just extend the  class with what's required for KWin. KWin decorations
> could then be used  in other environments with a different compositor
> and a different QPA  plugin. I'm CCing Martin as I'm pretty sure he'll
> have something to say,  especially considering the stance on SSDs vs
> CSDs.

One of the design goals of KDecoration2 was to make it possible to 
implement CSD with it.

I'm totally fine with upstreaming the implementation and agree to any 
license change required for it. But I'm not the only copyright holder, 
though probably > 90 % should be by me.

Personally I'm not interested in anything of it. I don't care whether Qt 
applications have good looking decorations. On Plasma we will continue 
to use server side decorations even if Qt uses our KDecoration2 (it 
provides a significant better performance in the compositor).

Cheers
Martin