IssueTracker

Component used: Version used: androidx.viewpager:1.0.0 Devices/Android versions reproduced on:

private void scrollToItem(int item, boolean smoothScroll, int velocity,
        boolean dispatchSelected) {
    final ItemInfo curInfo = infoForPosition(item);
    int destX = 0;
    if (curInfo != null) {
        final int width = getClientWidth();
        destX = (int) (width * Math.max(mFirstOffset,
                Math.min(curInfo.offset, mLastOffset)));
    }
    if (smoothScroll) {
        smoothScrollTo(destX, 0, velocity);
        if (dispatchSelected) {
            dispatchOnPageSelected(item);
        }
    } else {
        // Question: why 'dispatchOnPageSelected' invoked before 'scroll'?
        // there is a different behavior between 'smoothScroll' and 'non-smoothScroll'
        if (dispatchSelected) {
            dispatchOnPageSelected(item);
        }
        completeScroll(false);
        scrollTo(destX, 0);
        pageScrolled(destX);
    }
}

I want to calculate view exposure time.

If the view in a ViewPage, i add a 'OnPageChangeListener' to the ViewPage and expect the 'onPageSelected' callback could be invoked after page changed, so i can calculate view exposure state in this callback method.

But unfortunately, when i call the 'setCurrentItem(position, smoothScroll=false)' method, view exposure state can't be calculated correctly in the 'onPageSelected callback' because view is not scrolled in that moment.