[RFC wayland-protocols] inputfd - direct input access protocol

[Bastien Nocera]

On Tue, 2017-04-04 at 08:16 +0900, Carsten Haitzler wrote:
> On Fri, 31 Mar 2017 17:29:19 +1000 Peter Hutterer <peter.hutterer at who
> -t.net>
> said:
> 
> If you're going to do this ... why not just do it for keyboards,
> mice, touch
> panels etc. too?
> 
> My point is - the same reasons these other devices don't be lazy and
> stick
> their heads in the sand with these other devices are the same reasons
> joysticks, gamepads etc. etc. should also be UNDERSTOOD by the
> compositor
> before passing them on so they compositor can filter out special
> buttons (eg a
> power button and handle it internally, or a "home" button to go back
> to the
> home screen etc.).

Just like the superb joystick support in X11, amirite? :)

The protocol is a well-known, extensible one (evdev), already supported
by all the games on Linux that support joypads. And if it's not good
enough, your compositor can choose not to pass the raw device node's
file descriptor to the application, but pass a file descriptor with a
simpler protocol, or pass the joypad events as key presses.

Your compositor's choice.

Demarshalling and remarshalling the protocol means you have a layer of
indirection that's usually not necessary, and just makes it harder to
support new features from the bottom of the stack upwards.