[xmonad] XInput support in XMonad?

[Ilya Portnov]

Hello xmonad world.

My current desktop setup includes remote control unit, which sends 
keyboard events (for example, it sends Ctrl-P on Pause button). I want 
to handle such keypresses differently than keypresses from usual 
keyboard. For example, currently, if I press Ctrl-P on keyboard or Pause 
on the remote control, when Firefox window is active, both actions open 
Print dialog. But I want to run, for example, "mpc pause" on Pause button.

AFAIK, one way to differ key/button press events from different devices 
is to use XInput X11 extension. That extension might allow us to do many 
other funny things; for example, we could get pressure value from wacom 
tablets, and so on.

Technically, XInput support for XMonad will require FFI bindings to 
XInput client library (-lXi) and changes in events processing in xmonad 
core. Maybe, there should be new field in XMonad config, in addition to 
`keys' and `mouseBindings', to specify XInput events handlers.
Currently i'm working on xinput FFI bindings.

Questions are:
* Could such changes in xmonad core events processing be accepted for 
xmonad-core? Note that they will introduce new system library dependency 
(-lXi in addition to existing -lX11).
* What features of XInput might be useful for XMonad? For example, I 
don't know what to do with pressure value in window manager, but maybe 
someone knows?

Any other thoughts are welcome too.

With best regards,
Ilya Portnov.