Re: I can't understand the difference output of only a line differ

[Emmanuele Bassi <ebassi gmail com>]

On Thu, 2007-12-06 at 19:40 +0800, Binary Chen wrote:
>  
> > gdk_draw_image() forces a flush. but that is not the problem: you should
> > never use a while() loop inside a GTK+ application, because you are
> > effectively blocking the real main loop from spinning. remember: GTK+ is
> > not threaded.
>
> Yes, I know GTK+ is not threaded, there is only one thread running, so
> this make things more complecated, whats loop am I prohibit running?

the main loop that processes and delivers the events and handles the
redraws, and that is invoked by gtk_main(). you should read the GTK+
documentation, at this point.

> Again I'd like to say in both testing the gtk_main() is not running at
> all, so whats the difference? Can you point out the exact source of such
> headache problem?

the exact source is, in this case, a PEBKAC; the documentation available
on how GTK+ works (at this level, at least) is quite abundant; the GTK+
tutorial should shed some more light.

> > use a timeout or an idle source to repaint your window with the
> > GdkImage.
> This is just a testing program, not production code, I just want to find
> out whats happening.

what's happening is that you are blocking the main loop from ever
running, so any result you see is an undefined behaviour.

for the third time: use a timeout/idle source instead of the while()
loop to hook into the GTK+ main loop.

ciao,
 Emmanuele.

-- 
Emmanuele Bassi,
W: http://www.emmanuelebassi.net
B: http://log.emmanuelebassi.net