denisf_test.dart

// See https://github.com/flutter/flutter/issues/11222

import 'package:flutter/material.dart';

class TestPage2 extends StatefulWidget {

  @override
  _TestPageState2 createState() => new _TestPageState2();
}

class _TestPageState2 extends State<TestPage2> {

  Widget _buildItem(BuildContext context, int index) {
    return new ListTile(
      title: new Text('Title $index'),
      subtitle: new Text('Subtitle $index'),
    );
  }

  Widget _buildTab(int listSize, String title) {
    return new Stack(
      children: <Widget>[
        new Positioned(
          top: 0.0,
          left: 0.0,
          right: 0.0,
          child: new Material(
            elevation: 4.0,
            color: Colors.white,
            child: new Container(
              height: 48.0,
              child: new Center(
                child: new Text('$title Header'),
              ),
            ),
          ),
        ),
        new Positioned(
          top: 48.0,
          left: 0.0,
          right: 0.0,
          bottom: 0.0,
          child: new RefreshIndicator(
            onRefresh: () {},
            child: new ListView.builder(
              key: new PageStorageKey<String>(title),
              itemBuilder: _buildItem,
              itemCount: 12,
            ),
          ),
        ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return new DefaultTabController(
      length: 2,
      child: new Scaffold(
        body: new NestedScrollView(
          headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
            return [
              new SliverAppBar(
                expandedHeight: 256.0,
                backgroundColor: Colors.black26,
                title: new Text('App Title'),
                pinned: true,
                floating: true,
                bottom: new TabBar(
                  tabs: [
                    new Tab(text: 'Tab1'),
                    new Tab(text: 'Tab2'),
                  ]
                ),
              ),
            ];
          },
          body: new TabBarView(
            children: [
              _buildTab(32, 'Tab 1'),
              _buildTab(16, 'Tab 2'),
            ],
          ),
        ),
      ),
    );
  }
}

void main() {
  runApp(new MaterialApp(home: new TestPage2()));
}