lvgl/examples/widgets/list/lv_example_list_2.c

#include <stdio.h>

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

static lv_obj_t* list1;
static lv_obj_t* list2;

static lv_obj_t* currentButton = NULL;

static void event_handler(lv_event_t* e)
{
    lv_event_code_t code = lv_event_get_code(e);
    lv_obj_t* obj = lv_event_get_target(e);
    if (code == LV_EVENT_CLICKED)
    {
        LV_LOG_USER("Clicked: %s", lv_list_get_btn_text(list1, obj));

        if (currentButton == obj)
        {
            currentButton = NULL;
        }
        else
        {
            currentButton = obj;
        }
        lv_obj_t* parent = lv_obj_get_parent(obj);
        uint32_t i;
        for (i = 0; i < lv_obj_get_child_cnt(parent); i++)
        {
            lv_obj_t* child = lv_obj_get_child(parent, i);
            if (child == currentButton)
            {
                lv_obj_add_state(child, LV_STATE_CHECKED);
            }
            else
            {
                lv_obj_clear_state(child, LV_STATE_CHECKED);
            }
        }
    }
}

static void event_handler_top(lv_event_t* e)
{
    lv_event_code_t code = lv_event_get_code(e);
    if (code == LV_EVENT_CLICKED)
    {
        if (currentButton == NULL) return;
        lv_obj_move_background(currentButton);
        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_up(lv_event_t* e)
{
    lv_event_code_t code = lv_event_get_code(e);
    if ((code == LV_EVENT_CLICKED) || (code == LV_EVENT_LONG_PRESSED_REPEAT))
    {
        if (currentButton == NULL) return;
        lv_obj_move_up(currentButton);
        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_dn(lv_event_t* e)
{
    lv_event_code_t code = lv_event_get_code(e);
    if ((code == LV_EVENT_CLICKED) || (code == LV_EVENT_LONG_PRESSED_REPEAT))
    {
        if (currentButton == NULL) return;
        lv_obj_move_down(currentButton);
        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_bottom(lv_event_t* e)
{
    lv_event_code_t code = lv_event_get_code(e);
    if (code == LV_EVENT_CLICKED)
    {
        if (currentButton == NULL) return;
        lv_obj_move_foreground(currentButton);
        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_swap(lv_event_t* e)
{
    lv_event_code_t code = lv_event_get_code(e);
    // lv_obj_t* obj = lv_event_get_target(e);
    if ((code == LV_EVENT_CLICKED) || (code == LV_EVENT_LONG_PRESSED_REPEAT))
    {
        uint32_t first = 0;
        uint32_t last = lv_obj_get_child_cnt(list1);
        if (last > 1)
        {
            last--;
            while (first < last)
            {
                lv_obj_t* obj1 = lv_obj_get_child(list1, first);
                lv_obj_t* obj2 = lv_obj_get_child(list1, last);
                lv_obj_swap(obj1, obj2);
                first++;
                last--;
            }
            if (currentButton != NULL)
            {
                lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
            }
        }
    }
}

void lv_example_list_2(void)
{
    /*Create a list*/
    list1 = lv_list_create(lv_scr_act());
    lv_obj_set_size(list1, lv_pct(60), lv_pct(100));
    lv_obj_set_style_pad_row(list1, 5, 0);

    /*Add buttons to the list*/
    lv_obj_t* btn;
    int i;
    for (i = 0; i < 30; i++) {
        btn = lv_btn_create(list1);
        lv_obj_set_width(btn, lv_pct(50));
        lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);

        lv_obj_t* lab = lv_label_create(btn);
        lv_label_set_text_fmt(lab, "Item %d", i);
    }

    /*Select the first button by default*/
    currentButton = lv_obj_get_child(list1, 0);
    lv_obj_add_state(currentButton, LV_STATE_CHECKED);

    /*Create a second list with up and down buttons*/
    list2 = lv_list_create(lv_scr_act());
    lv_obj_set_size(list2, lv_pct(40), lv_pct(100));
    lv_obj_align(list2, LV_ALIGN_TOP_RIGHT, 0, 0);
    lv_obj_set_flex_flow(list2, LV_FLEX_FLOW_COLUMN);

    btn = lv_list_add_btn(list2, NULL, "Top");
    lv_obj_add_event_cb(btn, event_handler_top, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, LV_SYMBOL_UP, "Up");
    lv_obj_add_event_cb(btn, event_handler_up, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, LV_SYMBOL_DOWN, "Down");
    lv_obj_add_event_cb(btn, event_handler_dn, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, NULL, "Bottom");
    lv_obj_add_event_cb(btn, event_handler_bottom, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, LV_SYMBOL_SHUFFLE, "Shuffle");
    lv_obj_add_event_cb(btn, event_handler_swap, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);
}

#endif