First cut at a cross-"platform" X11/Wayland windowing library

[Brian Tarricone]

On Thu, Sep 22, 2022, at 03:38, Andrzej wrote:
> Hi Brian,
>
> This looks really good.

Thanks for taking a look!

> I like you are trying to bridge X11 and Wayland gaps first before 
> jumping into Wayland-specific implementation. Frankly, Xfce on Wayland 
> has no use to me (others may disagree) if it is too different from Xfce 
> on X11, or if the X11 version was to be discontinued.

I feel exactly the same way.  I've been using Xfce for almost 20 years now, and if Wayland really is the future of GUIs on Linux, I want to be able to use something that feels and works as close as possible to what I'm used to on X11.

> Ideally, the same 
> binaries would work seamlessly on both but that means tons of plumbing 
> work, discussions with devs of other DEs, as a lot of desktop features 
> (even basic ones) are not yet defined in Wayland or are unstable/desktop 
> specific (1).

Yeah, this worries me as well, and given how long I've been out of the *nix DE "scene", I'm feeling a bit overwhelmed about diving into this again.  But the lack of full stability and finalization is part of why I'd like to start now, instead of waiting until everything is set in stone.

> My assumption so far was such task would be too hard to pull off and, to 
> avoid damage to the X11 version of Xfce, I was advocating for separating 
> Xfce-wayland to a new component, so that both versions of the desktop 
> can be developed in parallel. Half measures would be problematic.

My hope is that won't be necessary, especially if we can get the right abstraction layers in place to avoid a situation where we have unreadable code bases full of ifdefs.  I think for some components like xfdesktop that will be pretty easy.  The panel will be a bit harder, but I think it's doable.  My main concern is of course xfwm4, but I'm optimistic there as well that the Wayland-specific code can be fairly well isolated, with the common window management code as a "bridge" between the Wayland and X11 worlds.

Only time and experimentation will tell, of course.  The important thing, I think, is that the various maintainers of the components are comfortable with the necessary changes, and that they don't add an unreasonable maintenance burden.

     -brian