text: def back_event_handler(e):
      obj = e.get_target()
      if menu.back_btn_is_root(obj):
          mbox1 = lv.msgbox(lv.scr_act(), "Hello", "Root back btn click.", None, True)
          mbox1.center()
  
  # Create a menu object
  menu = lv.menu(lv.scr_act())
  menu.set_mode_root_back_btn(lv.menu.ROOT_BACK_BTN.ENABLED)
  menu.add_event_cb(back_event_handler, lv.EVENT.CLICKED, None)
  menu.set_size(320, 240)
  menu.center()
  
  # Create a sub page
  sub_page = lv.menu_page(menu, None)
  cont = lv.menu_cont(sub_page)
  label = lv.label(cont)
  label.set_text("Hello, I am hiding here")
  
  # Create a main page
  main_page = lv.menu_page(menu, None)
  
  cont = lv.menu_cont(main_page)
  label = lv.label(cont)
  label.set_text("Item 1")
  
  cont = lv.menu_cont(main_page)
  label = lv.label(cont)
  label.set_text("Item 2")
  
  cont = lv.menu_cont(main_page)
  label = lv.label(cont)
  label.set_text("Item 3 (Click me!)")
  menu.set_load_page_event(cont, sub_page)
  
  menu.set_page(main_page)