title: Pass tap event to the child behind in Stack
body: <p>After watching a tutorial video about creating a custom PageView in Flutter, I've come across a problem.
  In order to achieve a custom PageView's page positions, I've used a stack of items that swipe left/right depending on the PageView that is placed in a Stack.fill() above every other element in the Stack.</p>
  
  <p>Here's the example of the code:</p>
  
  <pre><code>import 'package:flutter/material.dart';
  
  void main() =&gt; runApp(MyApp());
  
  class MyApp extends StatelessWidget {
    // This widget is the root of your application.
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        home: Home(),
      );
    }
  }
  
  class Home extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        appBar: AppBar(title: Text('Test')),
        body: Container(
          height: 200.0,
          child: Stack(
            children: &lt;Widget&gt;[
              Container(
                color: Colors.blueGrey,
                width: double.infinity,
                height: double.infinity,
                child: Material(
                  type: MaterialType.transparency,
                  child: InkWell(
                    onTap: () {
                      print('InkWell tapped');
                    },
                  ),
                ),
              ),
              Positioned.fill(
                child: PageView.builder(
                  itemBuilder: (context, index) {
                    return Container(
                      child: Center(
                        child: Text(
                          '$index',
                          style: TextStyle(
                            color: Colors.white,
                            fontSize: 25.0,
                          ),
                        ),
                      ),
                    );
                  },
                  itemCount: 4,
                ),
              ),
            ],
          ),
        ),
      );
    }
  }
  </code></pre>
  
  <p>The problem is that I want to trigger a Tap event on the InkWell behind the PageView, while still be able to swipe the PageView.</p>
  
  <p>Is it possible to pass the tap event to the element behind the PageView?
  Thanks.</p>
  
  <hr>
  
  <p>EDIT:</p>
  
  <p>Since you should not extend widgets in flutter, I've just made a copy of Scrollable class that uses a <strong>HitTestBehavior.translucent</strong> instead of <strong>HitTestBehavior.opaque</strong>. After that you create a copy of PageView using this new Scrollable.</p>
  
  <p>With such modification - the children behind the PageView start receiving gestures.</p>