Re: Collaboration on standard Wayland protocol extensions

[Peter Hutterer <peter hutterer who-t net>]

On Sun, Mar 27, 2016 at 04:34:37PM -0400, Drew DeVault wrote:
> Greetings! I am the maintainer of the Sway Wayland compositor.
>
> http://swaywm.org
>
> It's almost the Year of Wayland on the Desktop(tm), and I have
> reached out to each of the projects this message is addressed to (GNOME,
> Kwin, and wayland-devel) to collaborate on some shared protocol
> extensions for doing a handful of common tasks such as display
> configuration and taking screenshots. Life will be much easier for
> projects like ffmpeg and imagemagick if they don't have to implement
> compositor-specific code for capturing the screen!
>
> I want to start by establishing the requirements for these protocols.
> Broadly speaking, I am looking to create protocols for the following
> use-cases:
>
> - Screen capture
> - Output configuration
> - More detailed surface roles (should it be floating, is it a modal,
>   does it want to draw its own decorations, etc)
> - Input device configuration

a comment on the last point: input device configuration is either extremely
simple ("I want tapping enabled") or complex ("This device needs feature A
when condition B is met"). There is very little middle ground.

as a result, you either have some generic protocol that won't meet the niche
cases or you have a complex protocol that covers all the niche cases but
ends up being just a shim between the underlying implementation and the
compositor. Such a layer provides very little benefit but restricts what the
compositor can add in the future. It's not a good idea, imo.

Cheers,
   Peter

> I think that these are the core protocols necessary for
> cross-compositor compatability and to support most existing tools for
> X11 like ffmpeg. Considering the security goals of Wayland, it will also
> likely be necessary to implement some kind of protocol for requesting
> and granting sensitive permissions to clients.
>
> How does this list look? What sorts of concerns do you guys have with
> respect to what features each protocol needs to support? Have I missed
> any major protocols that we'll have to work on? Once we have a good list
> of requirements I'll start writing some XML.