public virtual void changed (string p0, TreeIter p1)
This signal is emitted each time after the user selected an item in the combo box, either by using the
mouse or the arrow keys. Contrary to GtkComboBox, GtkCellRendererCombo::changed is not emitted for changes made to a selected item in
the entry. The argument new_iter corresponds to the newly selected item in the combo box and it is relative to the
GtkTreeModel set via the model property on GtkCellRendererCombo.