title: How to pass Taps to widgets below the top widget?
body: <p>I'm trying to implement a very simple version of <a href="https://dribbble.com/shots/6160500-Card-Paginator-Component" rel="noreferrer">Card Paginator Component</a> (single card) in Flutter. </p>
  
  <p>Here is an example of a basic demo I've created:</p>
  
  <pre class="lang-dart prettyprint-override"><code>class CardComponent extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return Stack(
        children: [
          Positioned(
            top: 20.0,
            left: 20.0,
            child: 
            GestureDetector(
            // onTap should run while the text is visible on the screen
            // The text will become invisible when the Listview gest scrolled upwards
            onTap: (){print('text tapped');},
              child:
            Container(
            alignment:Alignment.topCenter,
            color: Colors.blueAccent,
          // This is fixed Text over which the card should scroll
          child: Text('Test Button')))),
          ListView(
            children: [
              //  This margin in first empty container pushes the whole card downward and makes the 'Test Button visible'
              Container(margin: EdgeInsets.only(top: 50.0)),
              // This is where the scrolling card actually starts
              Container(color: Colors.cyan[100], height: 120.0, width: 20.0),
              Container(color: Colors.cyan, height: 120.0, width: 20.0),
              Container(color: Colors.cyan[100], height: 120.0, width: 20.0),
              Container(color: Colors.cyan, height: 120.0, width: 20.0),
              Container(color: Colors.cyan[100], height: 120.0, width: 20.0),
              Container(color: Colors.cyan, height: 120.0, width: 20.0),
            ]
          )
        ],
      );
    }
  }
  
  </code></pre>
  
  <p>The issue I'm facing is, I'm unable to click the button when the card in not scrolled up. The fixed 'Test Button' is visible on the screen because of the empty dummy Container pushing the scrollable <code>ListView</code> downwards. Yet, since the <code>ListView</code> covers the full screen by default, hence the <code>onTap</code> never runs on tapping the button when it's visible.</p>
  
  <p><a href="https://i.stack.imgur.com/A0aAk.png" rel="noreferrer"><img src="https://i.stack.imgur.com/A0aAk.png" alt="enter image description here"></a>  </p>
  
  <p>If I surround the <code>ListView</code>/<code>SinglleChildScrollView</code> with <code>IgnorePointer</code> class, the whole scrolling behaviour stops and also any taps to the children of the ListView stops working which is not desired.</p>
  
  <p>How to tap on the button (backward widget in Stack) while allowing scrolling/tapping in ListView? Or should I approach building <a href="https://dribbble.com/shots/6160500-Card-Paginator-Component" rel="noreferrer">Card Paginator Component</a> is some different way?</p>