Re: force drawing area expose on button click

[Scott Rubin <slr2777 cs rit edu>]

Ok, I tried doing that before.  It doesn't work.  I get a runtime 
error.  Apparently the pointers act funny and the functions doesn't 
believe that it's actually a Widget. 

(oglbb:7399): Gtk-CRITICAL **: file gtkwidget.c: line 2176 
(gtk_widget_queue_draw): assertion `GTK_IS_WIDGET (widget)' failed

That is the exact error I get when using the sample code you provided.  
I tried poking it and changing a few things, but I either get that error 
or a segfault.  Soo, you got any other ideas?

By the way, thanks for replying so fast

-Scott


Soeren Sandmann wrote:

> Scott Rubin <slr2777 cs rit edu> writes:
>
>  
>
> > I think I may have done it wrong. To put it simply.  How can I force
> > the expose event to happen on the drawing_area widget whenever a
> > clicked event is signaled on one of my button widgets.  Thanks.
> >    
>
> You should just queue a draw on the widget. Don't process_updates();
> gtk+ will do that automatically in due course.
>
> The standard way to do what you want is simply to
>
>        g_signal_connect (G_OBJECT (button), "clicked",
>                          G_CALLBACK (redraw), drawing_area);
>
> with redraw() looking something like
>
>        static void
>        redraw (GtkWidget *button, 
>                GtkWidget *drawing_area)
>        {
>                gtk_widget_queue_draw (drawing_area);
>        }
>
> Søren
>