Re: Question about type casting.

["DC A" <adc4444 hotmail com>]

Thanks a lot for clearify this matter. So the bottom line is when there is 
no mention
about the type of widget in argument we can use GtkWidget there, right?


> From: Tristan Van Berkom <tristan van berkom gmail com>
> To: DC A <adc4444 hotmail com>
> CC: gtk-list gnome org
> Subject: Re: Question about type casting.
> Date: Sat, 08 Oct 2005 01:23:51 -0400
>
> DC A wrote:
> [...]
> > Why we cast for the first argument of this function but not the second 
> > one?
>
>    It seems a little wierd, but eventually you find that its just easier 
> to
> generalize where you can:
>
> /* gtk_button_new & gtk_vbox_new return `GtkWidget *',
>  * not `GtkButton *'
>  */
> GtkWidget *vbox   = gtk_vbox_new (FALSE, 0);
> GtkWidget *button = gtk_button_new ();
>
> /* Here we cast our `GtkWidget *vbox' to GTK_BOX to suit
>  * the api, most gtk functions take GtkWidget arguments
>  * (well, at least most container implementations do), so
>  * its just easier to declare every widget as `GtkWidget *'
>  * and not its subclass.
>  */
> gtk_box_pack_start (GTK_BOX (vbox), button, TRUE, TRUE, 0);
>
> Cheers,
>                               -Tristan