Re: [Xnee-devel] [slightly off-topic] preventing a client from receiving an event

[Henrik Sandklef]

Hi!

I do not have time to look at this right now, but a short answer will
perhaps help you a little. 

With RECORD extension you get copies of the protocol data. You cannot
'steal' them from the X server. What you can do is (I think) grab the
keyboard (passive grab but perhaps even active grab) and check the
events from there. ???? 




On Sat, 2004-05-15 at 20:58, Daniel Jácome Costa wrote:
> Hello,
> 
> My name is Daniel Costa, I live in Lisbon, Portugal, and since I readed the 
> article about Xnee in issue 117 of Linux Journal, I've been happily using 
> Xnee for automating a number of tasks, and I think it's a great application 
> and very useful, so let me start by thanking all the developers for writing 
> it.
> 
> Expressing my appreciation is not the only reason I'm posting to the list, 
> although it certainly should be motive enough :-)
> I need some help from you experienced X developers to point me in the right 
> direction
> 
> Let me explain:
> although where I work we are running mostly linux now, I have an old legacy 
> accounting/inventory MSDOS (horrors) application that I need to support, and 
> so far have been able to, using dosemu the app runs great, and everybody is 
> happy
> 
> or should I say, almost happy, because as it happens, the DOS app is buggy, 
> and there is a certain sequence of keystrokes that causes it to crash (that I 
> was able to determine thanks to xnee)
> 
> now what I am trying to do is this:
> write a program that monitors the keyboard events sent to the dosemu window, 
> and prevents the deadly key sequence from reaching it
> 
> I have some experience in X programming, mainly Tcl/Tk, Perl/Tk, C/gtk and 
> lately C++/Qt, but have never done something as low-level (Xlib frightens 
> me), and so I am a bit clueless as how to begin
> 
> I ask you: can this be done with slight modifications to xnee? 
> that is plan A, and I've started reading the code, but I haven't seen 
> anything in the RECORD extension that allows me to snatch events from the 
> queue, preventing them from reaching the client
> 
> plan B is to read the code from some window manager (fvwm, kwm, etc) to learn 
> how do they do it 
> 
> well, there you have it, any suggestion is very welcome
> 
> thanks in advance,
> best regards,
> daniel
>