StickyNavLayout.java

@Override
	public boolean onInterceptTouchEvent(MotionEvent ev)
	{
		int action = ev.getAction();
		float y = ev.getY();
 
		switch (action)
		{
		case MotionEvent.ACTION_DOWN:
			mLastY = y;
			break;
		case MotionEvent.ACTION_MOVE:
			float dy = y - mLastY;
 
			getCurrentScrollView();
 
			if (Math.abs(dy) > mTouchSlop)
			{
				mDragging = true;
				if (!isTopHidden
						|| (mInnerScrollView.getScrollY() == 0 && isTopHidden && dy > 0))
				{
					return true;
				}
			}
			break;
		}
		return super.onInterceptTouchEvent(ev);
	}