@Override
    public boolean onLayoutChild(CoordinatorLayout parent, final V child, int layoutDirection) {
        // First let the parent lay it out
        parent.onLayoutChild(child, layoutDirection);
        if (child instanceof BottomNavigationBar) {
            mViewRef = new WeakReference<>((BottomNavigationBar) child);
        }

        child.post(new Runnable() {
            @Override
            public void run() {
                mBottomNavHeight = child.getHeight();
            }
        });
        updateSnackBarPosition(parent, child, getSnackBarInstance(parent, child));

        return super.onLayoutChild(parent, child, layoutDirection);
    }
Class description

@author ashokvarma
@version 1.0
@see VerticalScrollingBehavior
@since 25 Mar 2016
common/src/main/java/com/sxjs/common/widget/bottomnavigation/behaviour/BottomVerticalScrollBehavior.java