Re: problem: gtk_image gives critical error

[Deependra Shekhawat <openbysource yahoo co in>]

Dear,

When I print the address of p in the funcl it prints a

address.
In the callback function it also prints the same for 
ptr.
Then what's the problem.
Also I use structures to pass data all the time to
the callback function then there's no error but with
this image widget there seems any problem.
Please clarify if I have any alternatives 

Regards

--- "David Necas (Yeti)" <yeti physics muni cz> wrote:

> On Tue, Apr 18, 2006 at 03:05:51AM -0700, Deependra
> Shekhawat wrote:
> > Hello friends,
> > This is my code:
> >
> > struct splash
> > {
> >     GtkWidget *splash_image;
> > };
> > void func1(void)
> > {
> >     GtkWidget *img;
> >     struct splash p;
>
> This structure is created on stack and exists only
> until the
> function func1 exits.
>
> >     img=gtk_image_new();
> >     p.splash_image=img;     
> >     
> >     g_signal_connect(G_OBJECT(button1),
> >                      "clicked",
> >                      G_CALLBACK(on_butt_clicked),
> >                      (gpointer) &p);
>
> Therefore &p becomes invalid immediately after you
> pass it
> to g_signal_connect().
>
> > }
> >
> > void on_butt_clicked(GtkButton *button,gpointer
> data)
> > {
> >     struct splash *ptr;
> >     ptr=(struct splash *)data;
> >
> >     //some code is here
> >     
> >     //following line gives error at execution time.
gtk_image_set_from_pixbuf(GTK_IMAGE((GtkWidget*)ptr->splash_image),buffer);
> > }
> >
> > Error is:
> > (splash_screen:3549): Gtk-CRITICAL **: file
> > gtkimage.c: line 772 (gtk_image_set_from_pixbuf):
> >  assertion `GTK_IS_IMAGE (image)' failed
>
> So, you are accessing some random piece of stack
> here.
>
> Yeti
>
>
> --
> That's enough.


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