public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
        mOnPageChangeListener = listener;
    }
Set a listener that will be invoked whenever the page changes or is incrementally
scrolled. See {@link ViewPager.OnPageChangeListener}.

@param listener Listener to set
dkplayer-sample/src/main/java/xyz/doikki/dkplayer/widget/VerticalViewPager.java