def detach (self):

     model = self.view.props.model
     sort_id, sort_order = tree_sortable_get_sort_column_id (model)
     if sort_id >= 0:
         self.app.state.sort_column = self.find_item_class (id = sort_id)
         if sort_order == gtk.SORT_ASCENDING:
             self.app.state.sort_order = "ascending"
         else:
             self.app.state.sort_order = "descending"
