Customizing GtkFileChooserDialog

[Olivier Guilyardi <ml xung org>]

Hi,

I need to add some extra saving options to a GtkFileChooserDialog. In this
purpose I'm trying to access its vbox with:

GtkWidget *label = gtk_button_new_with_label ("test");
gtk_container_add (GTK_CONTAINER (GTK_DIALOG (file_chooser_dialog)->vbox), label);

But it has no effect and produces no error on stderr. I also tried with
gtk_box_pack_start()

Can I customize it this way or must I create my dialog from scratch using
GtkFileChooserWidget and adding extra widgets?

Regards,

--
  Olivier