Adding a signal to an exixting widget

[Stefano Salvi <stefano salvi mn it>]

I'm using gtkmm-2.6 from Sarge.

I need a "scrollable DrawingArea" to insert into a ScrolledWindow widget.
To get the adjustmets to scroll it I need to add the 
signal_set_scroll_adjustments signal to my widget.
I added the SignalProxy with this declaration:

        Glib::SignalProxy2< void,Gtk::Adjustment*,Gtk::Adjustment* > 
signal_set_scroll_adjustments();

and initialized the proxy with the following code:

const Glib::SignalProxyInfo MemoryPanel_signal_set_scroll_adjustments_info =
{
  "set_scroll_adjustments",
  (GCallback) &MemoryPanel_signal_set_scroll_adjustments_callback,
  (GCallback) &MemoryPanel_signal_set_scroll_adjustments_callback
};

Glib::SignalProxy2< void,Gtk::Adjustment*,Gtk::Adjustment* > 
MemoryPanel::signal_set_scroll_adjustments()
{
  return Glib::SignalProxy2< void,Gtk::Adjustment*,Gtk::Adjustment* 
>(this, &MemoryPanel_signal_set_scroll_adjustments_info);
}

when the code runs I gat a runtime error claiming tha cannot connect to 
the "set_scroll_adjustments" signal, so I browsed the documentation to 
find a way to register the signal.

I found nothing in gtkmm and found a note on using 
gtk_object_class_user_signal_new(), but this function is present in 
GTK1.2 and not in GTK2.0.

What's the right method to add the signal?

Thank you
	Stefano Salvi