Menu (lv_menu)

Overview

The menu widget can be used to easily create multi-level menus. It handles the traversal between pages automatically.

Parts and Styles

The menu widget is built from the following objects:

• Main container: lv_menu_main_cont

• Main header: lv_menu_main_header_cont

• Back button: lv_button.h

• Back button icon: lv_image.h

• Main page: lv_menu_page

• Sidebar container: lv_menu_sidebar_cont

• Sidebar header: lv_menu_sidebar_header_cont

• Back button: lv_button.h

• Back button icon: lv_image.h

• Sidebar page: lv_menu_page

Usage

Create a menu

lv_menu_create(parent) creates a new empty menu.

Header mode

The following header modes exist:

• LV_MENU_HEADER_TOP_FIXED Header is positioned at the top.

• LV_MENU_HEADER_TOP_UNFIXED Header is positioned at the top and can be scrolled out of view.

• LV_MENU_HEADER_BOTTOM_FIXED Header is positioned at the bottom.

You can set header modes with lv_menu_set_mode_header(menu, LV_MENU_HEADER...).

Root back button mode

The following root back button modes exist:

• LV_MENU_ROOT_BACK_BTN_DISABLED

• LV_MENU_ROOT_BACK_BTN_ENABLED

You can set root back button modes with lv_menu_set_mode_root_back_button(menu, LV_MENU_ROOT_BACK_BTN...).

Create a menu page

lv_menu_page_create(menu, title) creates a new empty menu page. You can add any widgets to the page.

Set a menu page in the main area

Once a menu page has been created, you can set it to the main area with lv_menu_set_page(menu, page). NULL to clear main and clear menu history.

Set a menu page in the sidebar

Once a menu page has been created, you can set it to the sidebar with lv_menu_set_sidebar_page(menu, page). NULL to clear sidebar.

Linking between menu pages

For instance, you have created a button obj in the main page. When you click the button obj, you want it to open up a new page, use lv_menu_set_load_page_event(menu, obj, new page).

Create a menu container, section, separator

The following objects can be created so that it is easier to style the menu:

• lv_menu_cont_create(parent page) creates a new empty container.

• lv_menu_section_create(parent page) creates a new empty section.

• lv_menu_separator_create(parent page) creates a separator.

Events

• LV_EVENT_VALUE_CHANGED Sent when a page is shown.

  • lv_menu_get_cur_main_page(menu) returns a pointer to menu page that is currently displayed in main.

  • lv_menu_get_cur_sidebar_page(menu) returns a pointer to menu page that is currently displayed in sidebar.

• LV_EVENT_CLICKED Sent when a back button in a header from either main or sidebar is clicked. LV_OBJ_FLAG_EVENT_BUBBLE is enabled on the buttons so you can add events to the menu itself.

  • lv_menu_back_button_is_root(menu, button) to check if button is root back button

See the events of the Base object too.

Learn more about Events.

Keys

No keys are handled by the menu widget.

Learn more about Keys.

Example

Simple Menu

C code  

 View on GitHub

#include "../../lv_examples.h"
#if LV_USE_MENU && LV_BUILD_EXAMPLES

void lv_example_menu_1(void)
{
    /*Create a menu object*/
    lv_obj_t * menu = lv_menu_create(lv_screen_active());
    lv_obj_set_size(menu, lv_display_get_horizontal_resolution(NULL), lv_display_get_vertical_resolution(NULL));
    lv_obj_center(menu);

    lv_obj_t * cont;
    lv_obj_t * label;

    /*Create a sub page*/
    lv_obj_t * sub_page = lv_menu_page_create(menu, NULL);

    cont = lv_menu_cont_create(sub_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Hello, I am hiding here");

    /*Create a main page*/
    lv_obj_t * main_page = lv_menu_page_create(menu, NULL);

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 1");

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 2");

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 3 (Click me!)");
    lv_menu_set_load_page_event(menu, cont, sub_page);

    lv_menu_set_page(menu, main_page);
}

#endif

---

Simple Menu with root btn

C code  

 View on GitHub

#include "../../lv_examples.h"
#if LV_USE_MENU && LV_USE_MSGBOX && LV_BUILD_EXAMPLES

static void back_event_handler(lv_event_t * e)
{
    lv_obj_t * obj = lv_event_get_target(e);
    lv_obj_t * menu = lv_event_get_user_data(e);

    if(lv_menu_back_button_is_root(menu, obj)) {
        lv_obj_t * mbox1 = lv_msgbox_create(NULL);
        lv_msgbox_add_title(mbox1, "Hello");
        lv_msgbox_add_text(mbox1, "Root back btn click.");
        lv_msgbox_add_close_button(mbox1);
    }
}

void lv_example_menu_2(void)
{
    lv_obj_t * menu = lv_menu_create(lv_screen_active());
    lv_menu_set_mode_root_back_button(menu, LV_MENU_ROOT_BACK_BUTTON_ENABLED);
    lv_obj_add_event_cb(menu, back_event_handler, LV_EVENT_CLICKED, menu);
    lv_obj_set_size(menu, lv_display_get_horizontal_resolution(NULL), lv_display_get_vertical_resolution(NULL));
    lv_obj_center(menu);

    lv_obj_t * cont;
    lv_obj_t * label;

    /*Create a sub page*/
    lv_obj_t * sub_page = lv_menu_page_create(menu, NULL);

    cont = lv_menu_cont_create(sub_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Hello, I am hiding here");

    /*Create a main page*/
    lv_obj_t * main_page = lv_menu_page_create(menu, NULL);

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 1");

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 2");

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 3 (Click me!)");
    lv_menu_set_load_page_event(menu, cont, sub_page);

    lv_menu_set_page(menu, main_page);
}

#endif

---

Simple Menu with custom header

C code  

 View on GitHub

#include "../../lv_examples.h"
#if LV_USE_MENU && LV_BUILD_EXAMPLES

void lv_example_menu_3(void)
{
    /*Create a menu object*/
    lv_obj_t * menu = lv_menu_create(lv_screen_active());
    lv_obj_set_size(menu, lv_display_get_horizontal_resolution(NULL), lv_display_get_vertical_resolution(NULL));
    lv_obj_center(menu);

    /*Modify the header*/
    lv_obj_t * back_btn = lv_menu_get_main_header_back_button(menu);
    lv_obj_t * back_button_label = lv_label_create(back_btn);
    lv_label_set_text(back_button_label, "Back");

    lv_obj_t * cont;
    lv_obj_t * label;

    /*Create sub pages*/
    lv_obj_t * sub_1_page = lv_menu_page_create(menu, "Page 1");

    cont = lv_menu_cont_create(sub_1_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Hello, I am hiding here");

    lv_obj_t * sub_2_page = lv_menu_page_create(menu, "Page 2");

    cont = lv_menu_cont_create(sub_2_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Hello, I am hiding here");

    lv_obj_t * sub_3_page = lv_menu_page_create(menu, "Page 3");

    cont = lv_menu_cont_create(sub_3_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Hello, I am hiding here");

    /*Create a main page*/
    lv_obj_t * main_page = lv_menu_page_create(menu, NULL);

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 1 (Click me!)");
    lv_menu_set_load_page_event(menu, cont, sub_1_page);

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 2 (Click me!)");
    lv_menu_set_load_page_event(menu, cont, sub_2_page);

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 3 (Click me!)");
    lv_menu_set_load_page_event(menu, cont, sub_3_page);

    lv_menu_set_page(menu, main_page);
}

#endif

---

Simple Menu with floating btn to add new menu page

C code  

 View on GitHub

#include "../../lv_examples.h"
#if LV_USE_MENU && LV_BUILD_EXAMPLES

static uint32_t btn_cnt = 1;
static lv_obj_t * main_page;
static lv_obj_t * menu;

static void float_button_event_cb(lv_event_t * e)
{
    LV_UNUSED(e);

    btn_cnt++;

    lv_obj_t * cont;
    lv_obj_t * label;

    lv_obj_t * sub_page = lv_menu_page_create(menu, NULL);

    cont = lv_menu_cont_create(sub_page);
    label = lv_label_create(cont);
    lv_label_set_text_fmt(label, "Hello, I am hiding inside %"LV_PRIu32"", btn_cnt);

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text_fmt(label, "Item %"LV_PRIu32"", btn_cnt);
    lv_menu_set_load_page_event(menu, cont, sub_page);

    lv_obj_scroll_to_view_recursive(cont, LV_ANIM_ON);
}

void lv_example_menu_4(void)
{
    /*Create a menu object*/
    menu = lv_menu_create(lv_screen_active());
    lv_obj_set_size(menu, lv_display_get_horizontal_resolution(NULL), lv_display_get_vertical_resolution(NULL));
    lv_obj_center(menu);

    lv_obj_t * cont;
    lv_obj_t * label;

    /*Create a sub page*/
    lv_obj_t * sub_page = lv_menu_page_create(menu, NULL);

    cont = lv_menu_cont_create(sub_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Hello, I am hiding inside the first item");

    /*Create a main page*/
    main_page = lv_menu_page_create(menu, NULL);

    cont = lv_menu_cont_create(main_page);
    label = lv_label_create(cont);
    lv_label_set_text(label, "Item 1");
    lv_menu_set_load_page_event(menu, cont, sub_page);

    lv_menu_set_page(menu, main_page);

    /*Create floating btn*/
    lv_obj_t * float_btn = lv_button_create(lv_screen_active());
    lv_obj_set_size(float_btn, 50, 50);
    lv_obj_add_flag(float_btn, LV_OBJ_FLAG_FLOATING);
    lv_obj_align(float_btn, LV_ALIGN_BOTTOM_RIGHT, -10, -10);
    lv_obj_add_event_cb(float_btn, float_button_event_cb, LV_EVENT_CLICKED, menu);
    lv_obj_set_style_radius(float_btn, LV_RADIUS_CIRCLE, 0);
    lv_obj_set_style_bg_image_src(float_btn, LV_SYMBOL_PLUS, 0);
    lv_obj_set_style_text_font(float_btn, lv_theme_get_font_large(float_btn), 0);
}

#endif

---

Complex Menu

C code  

 View on GitHub

#include "../../lv_examples.h"
#if LV_USE_MENU && LV_USE_MSGBOX && LV_BUILD_EXAMPLES

enum {
    LV_MENU_ITEM_BUILDER_VARIANT_1,
    LV_MENU_ITEM_BUILDER_VARIANT_2
};
typedef uint8_t lv_menu_builder_variant_t;

static void back_event_handler(lv_event_t * e);
static void switch_handler(lv_event_t * e);
lv_obj_t * root_page;
static lv_obj_t * create_text(lv_obj_t * parent, const char * icon, const char * txt,
                              lv_menu_builder_variant_t builder_variant);
static lv_obj_t * create_slider(lv_obj_t * parent,
                                const char * icon, const char * txt, int32_t min, int32_t max, int32_t val);
static lv_obj_t * create_switch(lv_obj_t * parent,
                                const char * icon, const char * txt, bool chk);

void lv_example_menu_5(void)
{
    lv_obj_t * menu = lv_menu_create(lv_screen_active());

    lv_color_t bg_color = lv_obj_get_style_bg_color(menu, 0);
    if(lv_color_brightness(bg_color) > 127) {
        lv_obj_set_style_bg_color(menu, lv_color_darken(lv_obj_get_style_bg_color(menu, 0), 10), 0);
    }
    else {
        lv_obj_set_style_bg_color(menu, lv_color_darken(lv_obj_get_style_bg_color(menu, 0), 50), 0);
    }
    lv_menu_set_mode_root_back_button(menu, LV_MENU_ROOT_BACK_BUTTON_ENABLED);
    lv_obj_add_event_cb(menu, back_event_handler, LV_EVENT_CLICKED, menu);
    lv_obj_set_size(menu, lv_display_get_horizontal_resolution(NULL), lv_display_get_vertical_resolution(NULL));
    lv_obj_center(menu);

    lv_obj_t * cont;
    lv_obj_t * section;

    /*Create sub pages*/
    lv_obj_t * sub_mechanics_page = lv_menu_page_create(menu, NULL);
    lv_obj_set_style_pad_hor(sub_mechanics_page, lv_obj_get_style_pad_left(lv_menu_get_main_header(menu), 0), 0);
    lv_menu_separator_create(sub_mechanics_page);
    section = lv_menu_section_create(sub_mechanics_page);
    create_slider(section, LV_SYMBOL_SETTINGS, "Velocity", 0, 150, 120);
    create_slider(section, LV_SYMBOL_SETTINGS, "Acceleration", 0, 150, 50);
    create_slider(section, LV_SYMBOL_SETTINGS, "Weight limit", 0, 150, 80);

    lv_obj_t * sub_sound_page = lv_menu_page_create(menu, NULL);
    lv_obj_set_style_pad_hor(sub_sound_page, lv_obj_get_style_pad_left(lv_menu_get_main_header(menu), 0), 0);
    lv_menu_separator_create(sub_sound_page);
    section = lv_menu_section_create(sub_sound_page);
    create_switch(section, LV_SYMBOL_AUDIO, "Sound", false);

    lv_obj_t * sub_display_page = lv_menu_page_create(menu, NULL);
    lv_obj_set_style_pad_hor(sub_display_page, lv_obj_get_style_pad_left(lv_menu_get_main_header(menu), 0), 0);
    lv_menu_separator_create(sub_display_page);
    section = lv_menu_section_create(sub_display_page);
    create_slider(section, LV_SYMBOL_SETTINGS, "Brightness", 0, 150, 100);

    lv_obj_t * sub_software_info_page = lv_menu_page_create(menu, NULL);
    lv_obj_set_style_pad_hor(sub_software_info_page, lv_obj_get_style_pad_left(lv_menu_get_main_header(menu), 0), 0);
    section = lv_menu_section_create(sub_software_info_page);
    create_text(section, NULL, "Version 1.0", LV_MENU_ITEM_BUILDER_VARIANT_1);

    lv_obj_t * sub_legal_info_page = lv_menu_page_create(menu, NULL);
    lv_obj_set_style_pad_hor(sub_legal_info_page, lv_obj_get_style_pad_left(lv_menu_get_main_header(menu), 0), 0);
    section = lv_menu_section_create(sub_legal_info_page);
    for(uint32_t i = 0; i < 15; i++) {
        create_text(section, NULL,
                    "This is a long long long long long long long long long text, if it is long enough it may scroll.",
                    LV_MENU_ITEM_BUILDER_VARIANT_1);
    }

    lv_obj_t * sub_about_page = lv_menu_page_create(menu, NULL);
    lv_obj_set_style_pad_hor(sub_about_page, lv_obj_get_style_pad_left(lv_menu_get_main_header(menu), 0), 0);
    lv_menu_separator_create(sub_about_page);
    section = lv_menu_section_create(sub_about_page);
    cont = create_text(section, NULL, "Software information", LV_MENU_ITEM_BUILDER_VARIANT_1);
    lv_menu_set_load_page_event(menu, cont, sub_software_info_page);
    cont = create_text(section, NULL, "Legal information", LV_MENU_ITEM_BUILDER_VARIANT_1);
    lv_menu_set_load_page_event(menu, cont, sub_legal_info_page);

    lv_obj_t * sub_menu_mode_page = lv_menu_page_create(menu, NULL);
    lv_obj_set_style_pad_hor(sub_menu_mode_page, lv_obj_get_style_pad_left(lv_menu_get_main_header(menu), 0), 0);
    lv_menu_separator_create(sub_menu_mode_page);
    section = lv_menu_section_create(sub_menu_mode_page);
    cont = create_switch(section, LV_SYMBOL_AUDIO, "Sidebar enable", true);
    lv_obj_add_event_cb(lv_obj_get_child(cont, 2), switch_handler, LV_EVENT_VALUE_CHANGED, menu);

    /*Create a root page*/
    root_page = lv_menu_page_create(menu, "Settings");
    lv_obj_set_style_pad_hor(root_page, lv_obj_get_style_pad_left(lv_menu_get_main_header(menu), 0), 0);
    section = lv_menu_section_create(root_page);
    cont = create_text(section, LV_SYMBOL_SETTINGS, "Mechanics", LV_MENU_ITEM_BUILDER_VARIANT_1);
    lv_menu_set_load_page_event(menu, cont, sub_mechanics_page);
    cont = create_text(section, LV_SYMBOL_AUDIO, "Sound", LV_MENU_ITEM_BUILDER_VARIANT_1);
    lv_menu_set_load_page_event(menu, cont, sub_sound_page);
    cont = create_text(section, LV_SYMBOL_SETTINGS, "Display", LV_MENU_ITEM_BUILDER_VARIANT_1);
    lv_menu_set_load_page_event(menu, cont, sub_display_page);

    create_text(root_page, NULL, "Others", LV_MENU_ITEM_BUILDER_VARIANT_1);
    section = lv_menu_section_create(root_page);
    cont = create_text(section, NULL, "About", LV_MENU_ITEM_BUILDER_VARIANT_1);
    lv_menu_set_load_page_event(menu, cont, sub_about_page);
    cont = create_text(section, LV_SYMBOL_SETTINGS, "Menu mode", LV_MENU_ITEM_BUILDER_VARIANT_1);
    lv_menu_set_load_page_event(menu, cont, sub_menu_mode_page);

    lv_menu_set_sidebar_page(menu, root_page);

    lv_obj_send_event(lv_obj_get_child(lv_obj_get_child(lv_menu_get_cur_sidebar_page(menu), 0), 0), LV_EVENT_CLICKED,
                      NULL);
}

static void back_event_handler(lv_event_t * e)
{
    lv_obj_t * obj = lv_event_get_target(e);
    lv_obj_t * menu = lv_event_get_user_data(e);

    if(lv_menu_back_button_is_root(menu, obj)) {
        lv_obj_t * mbox1 = lv_msgbox_create(NULL);
        lv_msgbox_add_title(mbox1, "Hello");
        lv_msgbox_add_text(mbox1, "Root back btn click.");
        lv_msgbox_add_close_button(mbox1);
    }
}

static void switch_handler(lv_event_t * e)
{
    lv_event_code_t code = lv_event_get_code(e);
    lv_obj_t * menu = lv_event_get_user_data(e);
    lv_obj_t * obj = lv_event_get_target(e);
    if(code == LV_EVENT_VALUE_CHANGED) {
        if(lv_obj_has_state(obj, LV_STATE_CHECKED)) {
            lv_menu_set_page(menu, NULL);
            lv_menu_set_sidebar_page(menu, root_page);
            lv_obj_send_event(lv_obj_get_child(lv_obj_get_child(lv_menu_get_cur_sidebar_page(menu), 0), 0), LV_EVENT_CLICKED,
                              NULL);
        }
        else {
            lv_menu_set_sidebar_page(menu, NULL);
            lv_menu_clear_history(menu); /* Clear history because we will be showing the root page later */
            lv_menu_set_page(menu, root_page);
        }
    }
}

static lv_obj_t * create_text(lv_obj_t * parent, const char * icon, const char * txt,
                              lv_menu_builder_variant_t builder_variant)
{
    lv_obj_t * obj = lv_menu_cont_create(parent);

    lv_obj_t * img = NULL;
    lv_obj_t * label = NULL;

    if(icon) {
        img = lv_image_create(obj);
        lv_image_set_src(img, icon);
    }

    if(txt) {
        label = lv_label_create(obj);
        lv_label_set_text(label, txt);
        lv_label_set_long_mode(label, LV_LABEL_LONG_SCROLL_CIRCULAR);
        lv_obj_set_flex_grow(label, 1);
    }

    if(builder_variant == LV_MENU_ITEM_BUILDER_VARIANT_2 && icon && txt) {
        lv_obj_add_flag(img, LV_OBJ_FLAG_FLEX_IN_NEW_TRACK);
        lv_obj_swap(img, label);
    }

    return obj;
}

static lv_obj_t * create_slider(lv_obj_t * parent, const char * icon, const char * txt, int32_t min, int32_t max,
                                int32_t val)
{
    lv_obj_t * obj = create_text(parent, icon, txt, LV_MENU_ITEM_BUILDER_VARIANT_2);

    lv_obj_t * slider = lv_slider_create(obj);
    lv_obj_set_flex_grow(slider, 1);
    lv_slider_set_range(slider, min, max);
    lv_slider_set_value(slider, val, LV_ANIM_OFF);

    if(icon == NULL) {
        lv_obj_add_flag(slider, LV_OBJ_FLAG_FLEX_IN_NEW_TRACK);
    }

    return obj;
}

static lv_obj_t * create_switch(lv_obj_t * parent, const char * icon, const char * txt, bool chk)
{
    lv_obj_t * obj = create_text(parent, icon, txt, LV_MENU_ITEM_BUILDER_VARIANT_1);

    lv_obj_t * sw = lv_switch_create(obj);
    lv_obj_add_state(sw, chk ? LV_STATE_CHECKED : 0);

    return obj;
}

#endif

---

API

lv_menu.h