[systemd-devel] [PATCH udev 0/1] export device sizes

[Carlos Garnacho]

Hey,

I'm sending a patch for udev to export ID_INPUT_[WIDTH|HEIGHT]_MM
properties for tablets and touchscreens. Even if it's scarcely useful info,
IMO it fills a small gap with an eye on Wayland/X11-less sessions.

As some background, I've been hacking on making GNOME input device
configuration on Wayland 1:1 with X. The real gist of the task has been 
traditionally carried out by a separate daemon, which is moving for the
most part to the wm/compositor itself.

However, there's some things we feel should be kept out of the compositor.
Most namely, the policies (or crazy heuristics) applied to determine how
touchscreens and tablets are mapped to the available monitors. The current
work goes towards a split where the compositor systematically maps to outputs
as defined by settings, and gnome-settings-daemon determines which output
seems best. This also caters for devices with no integrated output,
which are thus switchable.

For the most part, the information we can fetch from udev is enough to
implement this in a windowing-independent fashion, the only thing that's
missing is this, and input/output size matching turns out to be the most
reliable of the checks we perform, hence my request to consider this.

Cheers,
  Carlos

 Makefile.am                              |  14 +++
 rules/60-input_abs_size.rules            |   8 ++
 src/udev/input_abs_size/input_abs_size.c | 177 +++++++++++++++++++++++++++++++
 3 files changed, 199 insertions(+)