title: ScrollController how can I detect Scroll start, stop and scrolling?
body: <p>I'm using ScrollController for <code>SingleChildScrollView</code> widget where I want to detect when scroll start, end/stop and still scrolling? </p>
  
  <p>How can I detect, I'm using <code>Listene</code></p>
  
  <pre><code>scrollController = ScrollController()
        ..addListener(() {
          scrollOffset = _scrollController.offset;
        });
  </code></pre>
  
  <p>Also try with <code>_scrollController.position.activity.velocity</code> but didn't help me.</p>
  
  <p>Also there are </p>
  
  <pre><code>_scrollController.position.didEndScroll();
  _scrollController.position.didStartScroll();
  </code></pre>
  
  <p>But how can I use it?</p>