LVGL 8.2 Textarea

Simple Text area

static void textarea_event_handler(lv_event_t* e)
{
    
    lv_obj_t* ta = lv_event_get_target(e);
    LV_LOG_USER("Enter was pressed. The current text is: %s", lv_textarea_get_text(ta));
}
static void btnm_event_handler(lv_event_t* e)
{
    
    lv_obj_t* obj = lv_event_get_target(e);
    lv_obj_t* ta = lv_event_get_user_data(e);
    const char* txt = lv_btnmatrix_get_btn_text(obj, lv_btnmatrix_get_selected_btn(obj));
    if (strcmp(txt, LV_SYMBOL_BACKSPACE) == 0) lv_textarea_del_char(ta);
    else if (strcmp(txt, LV_SYMBOL_NEW_LINE) == 0) lv_event_send(ta, LV_EVENT_READY, NULL);
    else lv_textarea_add_text(ta, txt);
}

static void lv_example_textarea_1(void)
{
    
    lv_obj_t* ta = lv_textarea_create(lv_scr_act());
    lv_textarea_set_one_line(ta, true);
    lv_obj_align(ta, LV_ALIGN_TOP_MID, 0, 10);
    lv_obj_add_event_cb(ta, textarea_event_handler, LV_EVENT_READY, ta);
    lv_obj_add_state(ta, LV_STATE_FOCUSED); /*To be sure the cursor is visible*/
    static const char* btnm_map[] = {
     "1", "2", "3", "\n",
    "4", "5", "6", "\n",
    "7", "8", "9", "\n",
    LV_SYMBOL_BACKSPACE, "0", LV_SYMBOL_NEW_LINE, ""
    };
    lv_obj_t* btnm = lv_btnmatrix_create(lv_scr_act());
    lv_obj_set_size(btnm, 200, 150);
    lv_obj_align(btnm, LV_ALIGN_BOTTOM_MID, 0, -10);
    lv_obj_add_event_cb(btnm, btnm_event_handler, LV_EVENT_VALUE_CHANGED, ta);
    lv_obj_clear_flag(btnm, LV_OBJ_FLAG_CLICK_FOCUSABLE); /*To keep the text area focused on button clicks*/
    lv_btnmatrix_set_map(btnm, btnm_map);
}

• Running effect
  

Text area with password field

static void ta_event_cb(lv_event_t* e);
static lv_obj_t* kb;
static void lv_example_textarea_2(void)
{
    
    /*Create the password box*/
    lv_obj_t* pwd_ta = lv_textarea_create(lv_scr_act());
    lv_textarea_set_text(pwd_ta, "");
    lv_textarea_set_password_mode(pwd_ta, true);
    lv_textarea_set_one_line(pwd_ta, true);
    lv_obj_set_width(pwd_ta, lv_pct(40));
    lv_obj_set_pos(pwd_ta, 5, 20);
    lv_obj_add_event_cb(pwd_ta, ta_event_cb, LV_EVENT_ALL, NULL);
    /*Create a label and position it above the text box*/
    lv_obj_t* pwd_label = lv_label_create(lv_scr_act());
    lv_label_set_text(pwd_label, "Password:");
    lv_obj_align_to(pwd_label, pwd_ta, LV_ALIGN_OUT_TOP_LEFT, 0, 0);
    /*Create the one-line mode text area*/
    lv_obj_t* text_ta = lv_textarea_create(lv_scr_act());
    lv_textarea_set_one_line(text_ta, true);
    lv_textarea_set_password_mode(text_ta, false);
    lv_obj_set_width(text_ta, lv_pct(40));
    lv_obj_add_event_cb(text_ta, ta_event_cb, LV_EVENT_ALL, NULL);
    lv_obj_align(text_ta, LV_ALIGN_TOP_RIGHT, -5, 20);
    /*Create a label and position it above the text box*/
    lv_obj_t* oneline_label = lv_label_create(lv_scr_act());
    lv_label_set_text(oneline_label, "Text:");
    lv_obj_align_to(oneline_label, text_ta, LV_ALIGN_OUT_TOP_LEFT, 0, 0);
    /*Create a keyboard*/
    kb = lv_keyboard_create(lv_scr_act());
    lv_obj_set_size(kb, LV_HOR_RES, LV_VER_RES / 2);
    lv_keyboard_set_textarea(kb, pwd_ta); /*Focus it on one of the text areas to start*/


}
static void ta_event_cb(lv_event_t* e)
{
    
    lv_event_code_t code = lv_event_get_code(e);
    lv_obj_t* ta = lv_event_get_target(e);
    if (code == LV_EVENT_CLICKED || code == LV_EVENT_FOCUSED) {
    
        /*Focus on the clicked text area*/
        if (kb != NULL) lv_keyboard_set_textarea(kb, ta);
    }
    else if (code == LV_EVENT_READY) {
    
        LV_LOG_USER("Ready, current text: %s", lv_textarea_get_text(ta));
    }
}

• Running effect
  

Text auto-formatting

static void ta_event_cb(lv_event_t* e);
static lv_obj_t* kb;

/** * Automatically format text like a clock. E.g. "12:34" * Add the ':' automatically. */
static void lv_example_textarea_3(void)
{
    
    /*Create the text area*/
    lv_obj_t* ta = lv_textarea_create(lv_scr_act());
    lv_obj_add_event_cb(ta, ta_event_cb, LV_EVENT_VALUE_CHANGED, NULL);
    lv_textarea_set_accepted_chars(ta, "0123456789:");
    lv_textarea_set_max_length(ta, 5);
    lv_textarea_set_one_line(ta, true);
    lv_textarea_set_text(ta, "");

    /*Create a keyboard*/
    kb = lv_keyboard_create(lv_scr_act());
    lv_obj_set_size(kb, LV_HOR_RES, LV_VER_RES / 2);
    lv_keyboard_set_mode(kb, LV_KEYBOARD_MODE_NUMBER);
    lv_keyboard_set_textarea(kb, ta);
}
static void ta_event_cb(lv_event_t* e)
{
    
    lv_obj_t* ta = lv_event_get_target(e);
    const char* txt = lv_textarea_get_text(ta);
    if (txt[0] >= '0' && txt[0] <= '9' &&
        txt[1] >= '0' && txt[1] <= '9' &&
        txt[2] != ':') {
    
        lv_textarea_set_cursor_pos(ta, 2);
        lv_textarea_add_char(ta, ':');
    }
}

• Running effect