HansMuller

import 'package:flutter/material.dart';

class TwoLevelListDemo extends StatelessWidget {
  static const String routeName = '/two-level-list';

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(title: new Text('Expand/collapse list control')),
      body: new Column(

HansMuller

import 'package:flutter/material.dart';

class TwoLevelListDemo extends StatelessWidget {
  static const String routeName = '/two-level-list';

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(title: new Text('Expand/collapse list control')),
      body: new Column(

HansMuller

import 'package:flutter/material.dart';

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
  final int numTabs = 20;
  TabController tabController;

HansMuller

// See https://github.com/flutter/flutter/issues/10531

/*
In release mode the app is often asked to layout before the engine
has initialized to the point where the size of the screen is known.
In that case the app is built and laid out with 0x0 constraints and
then later with the screen's actual size.

The phantom tabbar scrolling seen here upon app startup is due to the
scrollable tabbar's scroll offset being "corrected" once the tab bar's

HansMuller

import 'package:flutter/material.dart';

class TabsDemo extends StatefulWidget {
  TabsDemo({Key key}) : super(key: key);

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

class _TabsDemoState extends State<TabsDemo> with TickerProviderStateMixin {

HansMuller

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

import 'package:flutter/material.dart';

class TestPage2 extends StatefulWidget {

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

HansMuller

import 'dart:math' as math;

import 'package:flutter/material.dart';

const _kHeadingGap = 8.0;
const _kMinHeadingsHeight = 90.0;

// Scroll animation from full-screen section heading column layout to row layout.
const Duration _kScrollDuration = const Duration(milliseconds: 400);

HansMuller

import 'dart:math' as math;

import 'package:flutter/material.dart';

const _kMidHeadingsHeight = 128.0;
const _kMinHeadingsHeight = 72.0;

// SectionHeadingsLayout computes the initial bounds of each heading based
// on the layout configuration:

HansMuller

import 'package:flutter/material.dart';

class NewsCardLayout extends MultiChildLayoutDelegate {
  NewsCardLayout();

  static const String title = 'title';
  static const String description = 'description';
  static const String source = 'source';

  @override

HansMuller

import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',