Re: XGrab Pointer does work...why???

[Rick Stikkers <rstikkers@telis.org>]

VNCoder wrote:

>G'day all,
>   Using the Ada C-binding for Xlib (see below). After create a
>window, I tried to grab the pointer immediately but it doesn't seem to
>grab at all.
>   Only if I put a delay (sleep for few seconds) before I grab then it
>works.
>   Anyone know what's happening??
>
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<snip>

You don't say what GUI builder, compiler, and platform you are using, 
but I have noticed similar behavior on a Rational VADS Ada 83 compiler 
under Solaris 2.6 using BXAda as a GUI builder.  I'm not too sure if I'm 
correct, but it almost seems that the combined implementation for 
XWindows puts some of the X processing into a task.  If you don't break 
out of the main processing, sometimes the additional background 
processing does not seem to have completed.  I have also noticed 
problems when you attempt to put the X processing routines into a 
separate task.  I've tried to do stuff that does not work when put into 
a task but the exact same code works in the main body of the program.  I 
pretty much gave up on trying to figure that one out a long time ago. 
 From my experience, you don't need a 5 second delay.  As long as you 
put some kind of delay it will allow the other code to finish processing 
and it should run.  I normally put a 0.01 second delay in and that seems 
to work fine for my applications.

    Rick