def move_cursor(row = nil)
      if row
        if (prev_item = items[current_row])
          main.draw_item prev_item
        end
        page = row / max_items
        switch_page page if page != current_page
        main.activate_pane row / maxy
        @current_row = row
      else
        @current_row = 0
      end

      item = items[current_row]
      main.draw_item item, current: true
      main.display current_page

      header_l.draw_current_file_info item
      @current_row
    end
def move_cursor(row = nil)
      if row
        if (prev_item = items[current_row])
          main.draw_item prev_item
        end
        page = row / max_items
        switch_page page if page != current_page
        main.activate_pane row / maxy
        @current_row = row
      else
        @current_row = 0
      end

      item = items[current_row]
      main.draw_item item, current: true
      main.display current_page

      header_l.draw_current_file_info item
      @current_row
    end
Move the cursor to specified row.

 The main window and the headers will be updated reflecting the displayed files and directories.
 The row number can be out of range of the current page.