Grabbing all events in a frame (with xelb?)

[Lars Ingebrigtsen]

If I say

(track-mouse (read-event))

I get pretty much all the events, but I don't get things like "the shift
key has been pressed".

Is there a way to get low-level events like that "natively" in Emacs?

If not, does anybody know whether one could use the xelb/xcb library to
do something like that?  I've tried looking at the exwm window manager,
and the answer seems to be "yes", although I've been unable to whip up a
simple, minimal way to, er, xcb:GrabKey and then get the events...

Is there a xelb mailing list?  :-)

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no