Am 2017-09-11 11:58, schrieb Sebastian Kügler:
Hi all,
One of the things we talked about during Akademy was better support for
convertible hardware. I've played around a bit with my Thinkpad X1 Yoga
and screen rotation. I can of course rotate the screen "manually"
through XRandR (Wayland is another story on that altogether), but that
will screw up the touchscreen. Doing some research, I found out that:
- touchscreen and display are completely separate things, the system
doesn't know they're sitting on top of each other
It does know, it's just not properly exposed. Libinput does have the
output information, it's just not set through udev in general, so in
practice we don't have it. But it's in general a fixable problem which
might need some work together with upstream and downstream. We need to
figure out whether that is never set or just in all distros except
Fedora (which is what I would expect).
Anyway for your design planning you should be able to assume that there
is a link between output and touchscreen.
- They need to be rotated separately
- rotation in X goes through XInput2, on Wayland, I don't know
KWin through libinput.
It's just an idea for now, but I'd like to get some feedback about it
at this point.
My feedback would be: ignore X11, concentrate on Wayland. Once Wayland
works, add it to X or ignore it.
Why:
1) Wayland is easier, we control the stack
2) We agreed that anything new should be Wayland first
3) Going X11 first or considering X11 at all might make the work on
Wayland more difficult
So go for the simple way and change Wayland first.
Cheers
Martin
