Need help for ccui ScrollView get current position

Hello
How are you today?
I am developing games with cocos2d-x v3.3
I am stuck on ccui ScrollView
Problem is this:
I am using ccui.ScrollView for Scroll my buttons.
I want get current position during scrolling…

local function onScroll(ref, type)
        if(ccui.TouchEventType.moved == type) then
                 ---I want get position of current scroll view
        end
end
self.scrollView = ccui.ScrollView:create()
....
self.scrollView:addTouchEventListener(onScroll)

How can I get scrollview’s position during scrolling?
Thank you
Best Regards