RE: [gtk-list] getting inside gtk_main()

["Ostroff, Jack H" <jack_h_ostroff groton pfizer com>]

Havoc's reply is probably the right way to go, but couldn't
you just wrap your while(gtk_events_pending()) in a while (1)
loop?  

> From: Paul Barton-Davis [mailto:pbd@Op.Net]
> i wanted to emulate XForm's way of handling signals, in which, without
> using a pipe or other heavyweight mechanism, i could notify a GTK UI
> that a (POSIX) signal had been received. this is hard to do because
> you can't use a signal handler - it runs asynchronously with respect
> to GTK, and we can't use GTK_THREAD_ENTER/GTK_THREAD_LEAVE because
> that may take too long to complete.
> 
> at the time, Miguel agreed that XForm's way of doing this was good,
> but pointed out that it wasn't part of the current GTK release, and
> unlikely to be part of a future release.  so, Miguel wrote:
> 
> >Actually, that makes sense.  You just need to have your own gtk_main:
> >
> >music_main ()
> >{
> >        while (gtk_events_pending ()){
> >                gtk_main_iteration ();
> >                if (alarm_handler_flag){
> >                        alarm_handler_flag = 0;
> >                        do_alarm_thingie ();
> >                }
> >        }
> >}                                        
> 
> finally, as i get around to porting the particular program (which
> makes heavy use of SIGALRM, every 20ms or so), i decided to try this
> out. 
> 
> alas, it doesn't work. in fact, the loop above isn't even what
> gtk_main() does. what this will do is process all X traffic necessary
> to flush the queue of pending stuff (created by prior calls to GTK
> functions), and then will exit the loop because gtk_events_pending()
> will return FALSE. this is OK when you're doing this as a recursive
> invocation of "gtk_main()", but its certainly not the equivalent of a
> top level gtk_main().
> 
> so, i'm looking for some way to say: "every time gtk_main_iteration()
> is done, please check this flag, do this if its set, and then unset
> it". as far as i can tell, the operation of gtk_main() fundamentally
> comes down to:
> 
>   if (g_main_is_running (main_loops->data))
>     {
>       GDK_THREADS_LEAVE ();
>       g_main_run (loop);
>       GDK_THREADS_ENTER ();
>       gdk_flush ();
>     }
> 
> in turn, g_main_run () mostly calls g_main_iterate() telling it to
> both block and dispatch:
> 
>   loop->is_running = TRUE;
>   while (loop->is_running)
>     g_main_iterate (TRUE, TRUE);
> 
> i could use:
>   while (gtk_main_iteration());
> but i have no idea how to know when to leave the loop.
> 
> in short, i can see no way to actually accomplish the effect i want
> without writing my own version of gtk_main(), which is OK, but clearly
> not very optimal.
> 
> any ideas ?
> 
> --p