1def back_event_handler(e):
2    obj = e.get_target()
3    if menu.back_btn_is_root(obj):
4        mbox1 = lv.msgbox(lv.scr_act(), "Hello", "Root back btn click.", None, True)
5        mbox1.center()
6
7# Create a menu object
8menu = lv.menu(lv.scr_act())
9menu.set_mode_root_back_btn(lv.menu.ROOT_BACK_BTN.ENABLED)
10menu.add_event_cb(back_event_handler, lv.EVENT.CLICKED, None)
11menu.set_size(320, 240)
12menu.center()
13
14# Create a sub page
15sub_page = lv.menu_page(menu, None)
16cont = lv.menu_cont(sub_page)
17label = lv.label(cont)
18label.set_text("Hello, I am hiding here")
19
20# Create a main page
21main_page = lv.menu_page(menu, None)
22
23cont = lv.menu_cont(main_page)
24label = lv.label(cont)
25label.set_text("Item 1")
26
27cont = lv.menu_cont(main_page)
28label = lv.label(cont)
29label.set_text("Item 2")
30
31cont = lv.menu_cont(main_page)
32label = lv.label(cont)
33label.set_text("Item 3 (Click me!)")
34menu.set_load_page_event(cont, sub_page)
35
36menu.set_page(main_page)