boolean shouldHide(View child, float yvel) {
        if (mSkipCollapsed) {
            return true;
        }
        if (child.getTop() < mMaxOffset) {
            // It should not hide, but collapse.
            return false;
        }
        final float newTop = child.getTop() + yvel * HIDE_FRICTION;
        return Math.abs(newTop - mMaxOffset) / (float) mPeekHeight > HIDE_THRESHOLD;
    }
Gets the current state of the bottom sheet.

@return One of {@link #STATE_EXPANDED}, {@link #STATE_COLLAPSED}, {@link #STATE_DRAGGING},
{@link #STATE_SETTLING}, and {@link #STATE_HIDDEN}.
vpbs/src/main/java/biz/laenger/android/vpbs/ViewPagerBottomSheetBehavior.java