X Core Protocol Scheme
ilan at astelecom.ru
Sat Dec 12 10:26:09 PST 2015
On Sat, Dec 12, 2015 at 06:31:55PM +0100, Michael Titke wrote:
> > This is described in Expose event paragraph in section 11 of the
> >protocol specification.
> >btw, this automatically means that you should receive Expose
> >events on the window you want to draw and therefore select Ex-
> >posure in the event mask at a window creation.
> Listening for expose events sounds like a good idea but the relation between
> graphics operation, their effect and expose events doesn't seem to be stated
> in the specifications. In the current experimental setup only keyboard
In fact, there is no relation between _graphic_ operations and
Expose events, and that fact is somehow mentioned both in de-
scription of WhenMapped hint in CreateWindow request and in de-
scription of Expose operation itself.
> events are in the event mask and it's a little bit surprising that the
> graphic operation has an effect only after a keyboard event has been
It is not.
You get your results just by coincidence.
> >> the padding bytes at the end. Now I really made it to open a window and
> > You have specs of MIT Magic Cookie? You lucky guy, I don't have
> >this one.
> It just needed some script "playing" the server to find out about the
> correct padding which usually should coincide with the terminating C string
> null byte.
It does not (see another my message).
> core protocol requests to receive those mappings for the current maps in
> effect are ignored by the server.
> >> finally deliver the protocol specifications where these kinds of
> >> interactions are layed out? Or some up to date updates on the core
> >> protocol? But as I have heard the X server doesn't even know about all
> >> registered extensions anymore - at least on Ubuntu with Unity one of
> >> the first events to be received was an impossible operation code of 192
> >> which wasn't reported by xdpyinfo to belong to any registered
> > Extension opcodes assigned by server at QueryExtension reply,
> >you should get that bytestream and find the extension name from
> >there. The number 192 may mean anything.
> The QueryExtension request isn't implemented in the experimental setup right
> now but as stated /xdpyinfo/ didn't report that operation code.
Bag my pardon: missed the word "Event" in you description.
The 192 event is synthetic event with code 64, and I don't know
what it should mean. Mostly because never interested in possibil-
ity of bogus events -- just drop them.
> >> extension. The current state of X11 is a bit puzzling: it when works
> > Yes, the protocol is not trivial. But it is consistent and core is
> > There are some features or extensions which lacks proper docu-
> >mentation (MIT-MAGIC-COOKIE-1 authentication, RENDER extension,
> >NV-GLX extension) but in fact all of them is crap, and you should
> >probably get rid of it.
> The core protocol is trivial - just not well documented. ;-) The XKB
Well, we have different opinions on this.
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