RE: [Qemu-devel] [PATCH] Support VNC PointerTypeChange psuedo-encoding

[Ramesh Dharan]

> The proper way to use new client message types (which is now 
> described 
> in the RFB spec) is to advertise a new pseudo-encoding for 
> that client 
> message type and wait for the server to send the 
> pseudo-encoding back to 
> the client.  That lets the client know that it is safe to use the new 
> client message type.  This is what I'm using for my shared 
> memory encoding.
> 
> Otherwise, there's no way to write a client that works with the 
> "enhanced" server and a normal VNC server.

Ok, yeah that makes sense. So yeah basically we would need to add new server
encodings for our client->server messages, and then you get the server to
send dummy "ack" messages for each one to say "yes, I understand this message
type"?

> The mechanism I described above is what the current preferred method 
> is.  If you want, we can bring the topic up with the VNC authors as 
> AFAIK I'm the only person with a reserved client message type.  Of 
> course, I think using a pseudo-encoding is a perfectly 
> suitable way to 
> address this problem.

Yeah the only problem I see with it is that I don't see how the server can
dynamically *change* the set of client messages that it accepts?

--
Ramesh