title: How to make Stack layout scroll-able using SingleChildScrollView?
body: <p>I am trying to make stack layout scrollable using SingleChildScrollView but it's not scrolling. Is SingleChildScrollView should be used here?</p>
  
  <p>I think I have given enough description to make anyone understand my question. More text here to satisfy StackOverflow's requirement to ask a question. Sorry about this. </p>
  
  <p>Here's example code.</p>
  
  <pre><code>  @override
    Widget build(BuildContext context) {
      return Scaffold(
        body: SafeArea(
          child: Container(
            child: Center(
              child: LayoutBuilder(
                builder:
                    (BuildContext context, BoxConstraints viewportConstraints) {
                  return SingleChildScrollView(
                    child: ConstrainedBox(
                      constraints: BoxConstraints(
                        minHeight: viewportConstraints.maxHeight,
                      ),
                      child: IntrinsicHeight(
                        child: Column(
                          children: &lt;Widget&gt;[
                            Container(
                              // A fixed-height child.
                              color: Colors.white,
                              height: 120.0,
                            ),
                            Expanded(
                              // A flexible child that will grow to fit the viewport but
                              // still be at least as big as necessary to fit its contents.
                              child: Container(
                                color: Colors.blue,
                                //height: 120.0,
                                child: Stack(
                                  children: &lt;Widget&gt;[
                                    Positioned(
                                      top: 0,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.red[100],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                    Positioned(
                                      top: 50,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.red[200],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                    Positioned(
                                      top: 100,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.red[300],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                    Positioned(
                                      top: 150,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.green[100],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                    Positioned(
                                      top: 200,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.green[200],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                    Positioned(
                                      top: 250,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.green[300],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                    Positioned(
                                      top: 300,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.yellow[100],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                    Positioned(
                                      top: 350,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.yellow[200],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                    Positioned(
                                      top: 400,
                                      left: 0,
                                      right: 0,
                                      child: Container(
                                        color: Colors.yellow[300],
                                        child: SizedBox(
                                          height: 300,
                                        ),
                                      ),
                                    ),
                                  ],
                                ),
                              ),
                            ),
                          ],
                        ),
                      ),
                    ),
                  );
                },
              ),
            ),
          ),
        ),
      );
    } 
  </code></pre>