input: use libxkbcommon to convert input events

This commit introduces a new kmscon_input_event structure which is
delivered to the input consumer. The information provided is
- The evdev scancode (=physical keyboard key).
- The X keysym (a symbol representing what the typist really intended).
- The active modifiers (e.g. Shift, Control..)
- The unicode (UCS-4) value, when it makes sense.

To achieve this we add two dependencies:
- libxkbcommon (this entails xproto and kbproto, but shouldn't bring any of
  big X dependencies)
- A function to translate keysyms to unicode values (taken from xlib,
  copied in-tree).

libxkbcommon is not an all-around solution, and requires various degrees
of supporting code, depending on how much we wish to support. This
commit implements the common, basic uses:
- Choosing layouts, variants and options
- Switching groups
- Switching shift-levels
- Setting modifiers
Though some stuff is missing. Further information in the comments.

test_input.c is updated to use the new input event interface. You can
change the layouts in input.c:init_input() and see what works and what
doesn't.

Signed-off-by: Ran Benita <ran234@gmail.com>
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/README b/README
index 3c809cd..1ba6f51 100644
--- a/README
+++ b/README
@@ -14,6 +14,7 @@ console.
       - glib
       - cairo
       - pango
+    - libxkbcommon
 
 == Install ==
   To compile the kmscon binary, run the standard autotools commands: