If another application has already set a grab on these keys then the call
would fail (BadAccess) and wmix stop. With the X error handler, we can
display a warning to user and continue anyway.
Signed-off-by: Christophe CURIS <christophe.curis@free.fr>
We can handle the keys AudioRaiseVolume, AudioLowerVolume and AudioMute,
so we ask the X server to send the key press event for them to us and
update the volume appropriately.
Signed-off-by: Christophe CURIS <christophe.curis@free.fr>