[RFC] Common input device library

[Jonas Ådahl]

Hi,

Wayland compositors are expected to deal with input device processing
themselves providing input events according to the Wayland protocol to
the clients. So far only weston has had more than basic support for
processing raw input events from evdev.

In order to avoid reimplementing support for various types of input
devices over and over again for every compositor, I extracted the input
device code from weston and put it in a new library called libinput.

The API is very inspired by the internal weston API, but with some
simplifications and generalizations. The idea is to make it possible for
other compositors to be able to plug it in and receive post-processed
events such as pointer motion events, key events, touch events.

This does not, however, mean that compositors shouldn't be able to
receive raw input events; it's just not there yet as there is no user of
such API.

While making these changes, I removed some functionality, namely
configuring evdev-touchpad via weston.ini. While it should obviously be
possible to configure devices, I have yet to made API for doing so. Device
detection logging is more limited as well.

The repository of libinput can currently be found here [0]. It is a
history rewrite of the weston repository, so the history of related files
are still intact.

I have created patches for weston (that I will submit by replying to this
E-mail) for consideration. I have tested this with a regular pointer
device, keyboard, touchpad, but not with a touch device.

This is more or less a RFC about this approach, and any input would be
appreciated.


Jonas

[0] http://github.com/jadahl/libinput