How to implement NestedScrolling on Android?

I spent quite a bit of time on this just going through android code trying to figure out what’s going on in NestedScrollView. The following should work.

public abstract class ParentOfNestedScrollView extends NestedScrollView{

    public ParentOfNestedScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /* 
    Have this return the range you want to scroll to until the 
    footer starts scrolling I have it as headerCard.getHeight() 
    on most implementations
    */
    protected abstract int getScrollRange();

    /*
    This has the parent do all the scrolling that happens until 
    you are ready for the child to scroll.
    */
    @Override
    public void onNestedPreScroll(View target, int dx, int dy, int[] consumed){
        if (dy > 0 && getScrollY() < getScrollRange()) {
            int oldScrollY = getScrollY();
            scrollBy(0, dy);
            consumed[1] = getScrollY() - oldScrollY;
        }
    }

    /*
    Sometimes the parent scroll intercepts the event when you don't
    want it to.  This prevents this from ever happening.
    */
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return false;
    }
}

Some of my code was borrowed from this question. From this I just extend this class as needed. My xml has the child as a NestedScrollView as a child and the parent as this. This doesn’t handle flings as well as I would like, that’s a work in progress.