Re: interrupting a big loop

[Allin Cottrell <cottrell wfu edu>]

On Wed, 19 May 2004, Tristan Van Berkom wrote:

> Allin Cottrell wrote:
> [...]
> > Thank you, this is just the sort of thing I was groping for.  I have
> > one more question.
> >
> >
> > >     /* It is possible that your callback
> > >      * `on_cancel_button_clicked()' was called
> > >      * during `gtk_main_iteration()'.
> > >      */
> > >     if (should_stop == TRUE) break;
> >
> >
> > What's the best way of implementing this?  Make "should_stop" a global
> > boolean that is initially set to FALSE, and is set TRUE within the
> > cancel button callback?  Or can one avoid a global?
>
> You could beat around the bush a little, like this:
>
> on_cancel_button_clicked(cancel_button, ... data) {
>      gboolean *should_stop = data;
>      if (should_stop)
>          *should_stop = TRUE;
> }
>
> expensive_callback(some_object... data) {
>      gboolean should_stop;
>      gulong        sigid;
>      should_stop = FALSE;
>      sigid = g_signal_connect(cancel_button, "clicked",
>                               on_cancel_button_clicked, &should_stop);
>      for (;;) {
>          /* ...
>           */
>          if (*should_stop) break;
>          /* ...
>           */
>      }
>      g_signal_disconnect(cancel_button, sigid);
> }
>
>
> But that is a little meticulous wouldn't you say ?

Yes, I would ;-)

The global state variable works fine.

Allin Cottrell