def set_menu_bar mb
      @menu_bar = mb
      add_widget mb
      mb.toggle_key ||= Ncurses.KEY_F2
      if !mb.toggle_key.nil?
        ch = mb.toggle_key
        bind_key(ch, 'Menu Bar') do |_form| 
          if !@menu_bar.nil?
            @menu_bar.toggle
            @menu_bar.handle_keys
          end
        end
      end
    end
def set_menu_bar mb
      @menu_bar = mb
      add_widget mb
      mb.toggle_key ||= Ncurses.KEY_F2
      if !mb.toggle_key.nil?
        ch = mb.toggle_key
        bind_key(ch, 'Menu Bar') do |_form| 
          if !@menu_bar.nil?
            @menu_bar.toggle
            @menu_bar.handle_keys
          end
        end
      end
    end
set this menubar as the form's menu bar.
 also bind the toggle_key for popping up.
 Should this not be at application level ?