[Xcb] How do I distinguish XKB events?

[Klemens Baum]

On Mon, Dec 28, 2015 at 7:15 PM,  <me at beroal.in.ua> wrote:
> So how do I distinguish XKB events?

This seems to be an omission from XCB. Most projects seem to work
around it by checking the pad0 member in xcb_generic_event_t (as seen
here: https://github.com/wxg4net/awesome-src/blob/8c0c2e8f56c6e269e7a3c11f66f95fb2f3751e76/xkb.c#L123)
or by defining their own generic struct
(https://github.com/andrenho/perminal/blob/f7406f3f4f4c95c54e0cc668593b114226cdcb4f/.old/cpp/frontend/xkb_keyboard.cc#L212).

To prepare a patch, we would first need to decide which header the
generic XKB struct should go into. As far as I know xcb/xkb.h is
entirely auto-generated, so if it should go in there we could add an
<event name="GenericEvent"> to proto/src/xkb.xml. But events list an
opcode in the `number' attribute, and c_client.py seems to assume this
is always the case in order to generate the corresponding #define. So
c_client.py would need an additional conditional check for events that
do not have an opcode.
Alternatively, it could go into xcb.h, which can be manually edited.

What do others think?