ListView - SCROLLVIEW_EVENT_SCROLLING event problem on 3.0-b2

cocos2d-x C++
#1

I made a ListView instance and add addEventListenerScrollView.
and I added some items to ListView.
then SCROLLVIEW_EVENT_SCROLLING event is occured.
but inner container position is wrong value.

I made a simple test code here.

bool TestScene::init()
{
    if (!Layer::init()) return false;

    _list = ListView::create();
    _list->setSize(Size(240, 200));
    _list->setDirection(SCROLLVIEW_DIR_VERTICAL);

    auto layout = Layout::create();
    layout->setSize(Size(240.0f, 150.0f));

    _list->setItemModel(layout);
    _list->addEventListenerScrollView(this, scrollvieweventselector(TestScene::testScroll));
    addChild(_list);

    _list->pushBackDefaultItem();
    _list->pushBackDefaultItem();

    scheduleOnce(schedule_selector(TestScene::checkListPosition), 1.f);
    return true;
}
void TestScene::testScroll(Object *pSender, ScrollviewEventType type)
{
    if (type == ScrollviewEventType::SCROLLVIEW_EVENT_SCROLLING){
        // this prints "x = 0.000000, y = 0.000000"
        log("x = %f, y = %f", _list->getInnerContainer()->getPositionX(), _list->getInnerContainer()->getPositionY());
    }
}

void TestScene::checkListPosition(float dt)
{
    // this prints "x = 0.000000, y = -100.000000"
    log("x = %f, y = %f", _list->getInnerContainer()->getPositionX(), _list->getInnerContainer()->getPositionY());
}

so, when adding items to list, I can’t calculate properly with scroll position.