method private _cb__up_button_clicked = fun () ->
    match view2.st_view#selection#get_selected_rows with
      | [path] ->
          let path_prev = GTree.Path.copy path in
            ignore (GTree.Path.prev path_prev);
            let i1 = GTree.Path.get_indices path
            and i2 = GTree.Path.get_indices path_prev in
              if i1 <> i2 then
                let row  = store2#get_row_reference path
                and row' = store2#get_row_reference path_prev in
                  i_bool (store2#swap row#iter row'#iter);
                  connect#raise_moved_up row row'
      | _ ->
          ()