How to keep button focused in list permanently

How-to
1

Focus on button in the list is lost after I click outside of the list object.

I need to have button focused permanently.

Weird thing is, that if I focused on one of the buttons by function lv_list_focus_btn, then it is working exactly as I want. I can click somewhere else outside of list object and button is still focused.

But if I focus button by clicking on it, then selection is lost after I click to outside of the list object.

I already tried to make workaround and put function lv_list_focus_btn inside event_handler of button but it did not work. Maybe it is a bug of list object.

Code to reproduce

In example below, the first button is selected by function lv_list_focus_btn.

static void event_handler(lv_obj_t * obj, lv_event_t event)
{
    if(event == LV_EVENT_CLICKED) {
        printf("Clicked: %s\n", lv_list_get_btn_text(obj));
    }
}

void lv_ex_list_2(void)
{
    /*Create a list*/
    lv_obj_t * list1 = lv_list_create(lv_scr_act(), NULL);
    lv_obj_set_size(list1, 160, 200);
    lv_obj_align(list1, NULL, LV_ALIGN_CENTER, 0, 0);

    /*Add buttons to the list*/
    lv_obj_t * list_btn;

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_FILE, "New");
    lv_obj_set_event_cb(list_btn, event_handler);
    lv_list_focus_btn(list1, list_btn);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_DIRECTORY, "Open");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_CLOSE, "Delete");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_EDIT, "Edit");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_SAVE, "Save");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_BELL, "Notify");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_BATTERY_FULL, "Battery");
    lv_obj_set_event_cb(list_btn, event_handler);
}
3 
static void event_handler(lv_obj_t * obj, lv_event_t event)
{
    if(event == LV_EVENT_CLICKED) {
        printf("Clicked: %s\n", lv_list_get_btn_text(obj));
    }
}

lv_obj_t * focused_btn;

void lv_ex_list_2(void)
{
    /*Create a list*/
    lv_obj_t * list1 = lv_list_create(lv_scr_act(), NULL);
    lv_obj_set_size(list1, 160, 200);
    lv_obj_align(list1, NULL, LV_ALIGN_CENTER, 0, 0);

    /*Add buttons to the list*/
    lv_obj_t * list_btn;

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_FILE, "New");
    lv_obj_set_event_cb(focused_btn, focused_event_handler);
    lv_list_focus_btn(list1, focused_btn);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_DIRECTORY, "Open");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_CLOSE, "Delete");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_EDIT, "Edit");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_SAVE, "Save");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_BELL, "Notify");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_BATTERY_FULL, "Battery");
    lv_obj_set_event_cb(list_btn, event_handler);
}

static void focused_event_handler(lv_obj_t * obj, lv_event_t event)
{
    if(event == LV_EVENT_CLICKED) {
        printf("Clicked: %s\n", lv_list_get_btn_text(obj));
        lv_list_focus_btn(obj, focused_btn);
    }
}
4

Try this code above.

5

Hi,
I know what you mean, but your code is wrong and program crash.
As I described above, I already had same idea but it did not work as expected.

Correct implementation of this idea look like this:

static lv_obj_t * list1;

static void event_handler(lv_obj_t * obj, lv_event_t event)
{
    if(event == LV_EVENT_CLICKED) {
        printf("Clicked: %s\n", lv_list_get_btn_text(obj));
        lv_list_focus_btn(list1, obj);
    }
}

void lv_ex_list_2(void)
{
    /*Create a list*/
    list1 = lv_list_create(lv_scr_act(), NULL);
    lv_obj_set_size(list1, 160, 200);
    lv_obj_align(list1, NULL, LV_ALIGN_CENTER, 0, 0);

    /*Add buttons to the list*/
    lv_obj_t * list_btn;

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_FILE, "New");
    lv_obj_set_event_cb(list_btn, event_handler);
    lv_list_focus_btn(list1, list_btn);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_DIRECTORY, "Open");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_CLOSE, "Delete");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_EDIT, "Edit");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_SAVE, "Save");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_BELL, "Notify");
    lv_obj_set_event_cb(list_btn, event_handler);

    list_btn = lv_list_add_btn(list1, LV_SYMBOL_BATTERY_FULL, "Battery");
    lv_obj_set_event_cb(list_btn, event_handler);
}

But as I said, this did not work.

6

please wait…

7

I can’t do this, I’m sorry. :frowning: