lvgl8.3.5 获取鼠标或者触摸点的实时坐标

 

static void scroll_event_cb(lv_event_t * e)
{
    lv_obj_t * cont = lv_event_get_target(e);

    lv_area_t cont_a;
     /*
     lv_obj_get_coords函数用于获取一个对象的坐标信息。
     */


    lv_indev_t* indev = lv_indev_get_act(); //获取输入设备
	if (indev == NULL)  return;
    lv_point_t   lv_point;
    lv_indev_get_point(indev, &lv_point);
    printf("[%s]  lv_point.x = %d  lv_point.y = %d \n", __func__, lv_point.x, lv_point.y);
   

    lv_obj_get_coords(cont, &cont_a);
    lv_coord_t cont_y_center = cont_a.y1 + lv_area_get_height(&cont_a) / 2;

    lv_coord_t r = lv_obj_get_height(cont) * 7 / 10;
    uint32_t i;
    uint32_t child_cnt = lv_obj_get_child_cnt(cont);
    for(i = 0; i < child_cnt; i++) {
        lv_obj_t * child = lv_obj_get_child(cont, i);
        lv_area_t child_a;
        lv_obj_get_coords(child, &child_a);

        lv_coord_t child_y_center = child_a.y1 + lv_area_get_height(&child_a) / 2;

        lv_coord_t diff_y = child_y_center - cont_y_center;
        diff_y = LV_ABS(diff_y);

        /*Get the x of diff_y on a circle.*/
        lv_coord_t x;
        /*If diff_y is out of the circle use the last point of the circle (the radius)*/
        if(diff_y >= r) {
            x = r;
        }
        else {
            /*Use Pythagoras theorem to get x from radius and y*/
            uint32_t x_sqr = r * r - diff_y * diff_y;
            lv_sqrt_res_t res;
            lv_sqrt(x_sqr, &res, 0x8000);   /*Use lvgl's built in sqrt root function*/
            x = r - res.i;
        }

        /*Translate the item by the calculated X coordinate*/
        //lv_obj_set_style_translate_x函数可以将一个对象的样式在水平方向上向左或向右偏移指定的距离。这可以用于创建阴影、强调或其他视觉效果。
        lv_obj_set_style_translate_x(child, x, 0);   

        /*Use some opacity with larger translations*/
        lv_opa_t opa = lv_map(x, 0, r, LV_OPA_TRANSP, LV_OPA_COVER);
        lv_obj_set_style_opa(child, LV_OPA_COVER - opa, 0);
    }
}

    lv_indev_t* indev = lv_indev_get_act(); //获取输入设备

    if (indev == NULL)  return;

    lv_point_t   lv_point;

    lv_indev_get_point(indev, &lv_point);

    printf("[%s]  lv_point.x = %d  lv_point.y = %d \n", __func__, lv_point.x, lv_point.y);