[Xcb] XCB naming conventions

[Bernardo Innocenti]

Bernardo Innocenti wrote:

> Maybe it's just outside of the scope of XCB, but it would help if the user
> could attach a "void *userdata" into windows so that it could get it back
> when needed.
> 
> Without something like this, applications and toolkits will have to
> perform the extra book-keeping of mapping XID's to context structures.
> I don't know much of XCB internals, but maybe XCB already has the
> data structures required to do this mapping.

Sorry for wasting your time with my uninformed guessing.  I've checked
the source and it's obvious XCB doesn't need to do anything to map
incoming events to XIDs.

So there would not be any (performance) advantage in doing the mapping
inside XCB.  It was also a bad idea because it would hard-code a policy
in the library that all applications would be invided to live with
(i.e. the same route taken by libX11 and the reason it was ditched).