[Gallery] Implement cupertino pull-to-refresh demo (#221)

* Implement cupertino pull-to-refresh demo

* Address feedback

gallery/gallery/lib/codeviewer/code_segments.dart

@@ -842,6 +842,377 @@ class CodeSegments {
     ]);
   }
 
+  static TextSpan cupertinoRefreshDemo(BuildContext context) {
+    final CodeStyle codeStyle = CodeStyle.of(context);
+    return TextSpan(children: [
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text: '// Copyright 2019 The Flutter team. All rights reserved.'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a'),
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text:
+              '// Use of this source code is governed by a BSD-style license that can be'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a'),
+      TextSpan(
+          style: codeStyle.commentStyle, text: '// found in the LICENSE file.'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a\u000a'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'import'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.stringStyle, text: '\u0027dart:math\u0027'),
+      TextSpan(style: codeStyle.baseStyle, text: ' show '),
+      TextSpan(style: codeStyle.classStyle, text: 'Random'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ';'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a\u000a'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'import'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(
+          style: codeStyle.stringStyle,
+          text: '\u0027package:flutter/cupertino.dart\u0027'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ';'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'import'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(
+          style: codeStyle.stringStyle,
+          text: '\u0027package:flutter/material.dart\u0027'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ';'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'import'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(
+          style: codeStyle.stringStyle,
+          text: '\u0027package:gallery/l10n/gallery_localizations.dart\u0027'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ';'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a\u000a'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'class'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(
+          style: codeStyle.classStyle, text: 'CupertinoRefreshControlDemo'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'extends'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'StatefulWidget'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '{'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a  '),
+      TextSpan(style: codeStyle.keywordStyle, text: '@override'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a  '),
+      TextSpan(
+          style: codeStyle.classStyle,
+          text: '_CupertinoRefreshControlDemoState'),
+      TextSpan(style: codeStyle.baseStyle, text: ' createState'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '()'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '=>'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a      '),
+      TextSpan(
+          style: codeStyle.classStyle,
+          text: '_CupertinoRefreshControlDemoState'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '();'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '}'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a\u000a'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'class'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(
+          style: codeStyle.classStyle,
+          text: '_CupertinoRefreshControlDemoState'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a    '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'extends'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'State'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '<'),
+      TextSpan(
+          style: codeStyle.classStyle, text: 'CupertinoRefreshControlDemo'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '>'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '{'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a  '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'static'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'const'),
+      TextSpan(style: codeStyle.baseStyle, text: ' listCount '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '='),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.numberStyle, text: '20'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ';'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a  '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'var'),
+      TextSpan(style: codeStyle.baseStyle, text: ' randomList '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '='),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'List'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '<'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'int'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '>.'),
+      TextSpan(style: codeStyle.baseStyle, text: 'generate'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'listCount'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ','),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'i'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ')'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '=>'),
+      TextSpan(style: codeStyle.baseStyle, text: ' i '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '+'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.numberStyle, text: '1'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ');'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a\u000a  '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'void'),
+      TextSpan(style: codeStyle.baseStyle, text: ' _shuffleList'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '()'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '=>'),
+      TextSpan(style: codeStyle.baseStyle, text: ' randomList'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '.'),
+      TextSpan(style: codeStyle.baseStyle, text: 'shuffle'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.classStyle, text: 'Random'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '());'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a\u000a  '),
+      TextSpan(style: codeStyle.keywordStyle, text: '@override'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a  '),
+      TextSpan(style: codeStyle.classStyle, text: 'Widget'),
+      TextSpan(style: codeStyle.baseStyle, text: ' build'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.classStyle, text: 'BuildContext'),
+      TextSpan(style: codeStyle.baseStyle, text: ' context'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ')'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '{'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a    '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'return'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'CupertinoPageScaffold'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a      child'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'CustomScrollView'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text: '// If left unspecified, the [CustomScrollView] appends an'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text:
+              '// [AlwaysScrollableScrollPhysics]. Behind the scene, the ScrollableState'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text:
+              '// will attach that [AlwaysScrollableScrollPhysics] to the output of'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text:
+              '// [ScrollConfiguration.of] which will be a [ClampingScrollPhysics]'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(style: codeStyle.commentStyle, text: '// on Android.'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text:
+              '// To demonstrate the iOS behavior in this demo and to ensure that the list'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text:
+              '// always scrolls, we specifically use a [BouncingScrollPhysics] combined'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(
+          style: codeStyle.commentStyle,
+          text: '// with a [AlwaysScrollableScrollPhysics]'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        physics'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'const'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'BouncingScrollPhysics'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a          parent'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(
+          style: codeStyle.classStyle, text: 'AlwaysScrollableScrollPhysics'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '(),'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        slivers'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '['),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
+      TextSpan(
+          style: codeStyle.classStyle, text: 'CupertinoSliverNavigationBar'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(
+          style: codeStyle.baseStyle,
+          text: '\u000a            automaticallyImplyLeading'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'false'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ','),
+      TextSpan(
+          style: codeStyle.baseStyle, text: '\u000a            largeTitle'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'Text'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a              '),
+      TextSpan(style: codeStyle.classStyle, text: 'GalleryLocalizations'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '.'),
+      TextSpan(style: codeStyle.baseStyle, text: 'of'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'context'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ').'),
+      TextSpan(
+          style: codeStyle.baseStyle, text: 'demoCupertinoPullToRefreshTitle'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ','),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a            '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
+      TextSpan(
+          style: codeStyle.classStyle, text: 'CupertinoSliverRefreshControl'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a            onRefresh'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '()'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '{'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a              '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'return'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'Future'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '<'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'void'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '>.'),
+      TextSpan(style: codeStyle.baseStyle, text: 'delayed'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.keywordStyle, text: 'const'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'Duration'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'seconds'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.numberStyle, text: '1'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '))'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a                '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '..'),
+      TextSpan(style: codeStyle.baseStyle, text: 'then'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '<'),
+      TextSpan(style: codeStyle.keywordStyle, text: 'void'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '>(('),
+      TextSpan(style: codeStyle.baseStyle, text: '_'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ')'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '{'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a                  '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'if'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'mounted'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ')'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '{'),
+      TextSpan(
+          style: codeStyle.baseStyle,
+          text: '\u000a                    setState'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '(()'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '=>'),
+      TextSpan(style: codeStyle.baseStyle, text: ' _shuffleList'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '());'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a                  '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '}'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a                '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '});'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a            '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '},'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
+      TextSpan(style: codeStyle.classStyle, text: 'SliverList'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a            delegate'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'SliverChildBuilderDelegate'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a              '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'context'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ','),
+      TextSpan(style: codeStyle.baseStyle, text: ' index'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ')'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '{'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a                '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'final'),
+      TextSpan(style: codeStyle.baseStyle, text: ' title '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '='),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'GalleryLocalizations'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '.'),
+      TextSpan(style: codeStyle.baseStyle, text: 'of'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'context'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ')'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a                    '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '.'),
+      TextSpan(style: codeStyle.baseStyle, text: 'starterAppDrawerItem'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'randomList'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '['),
+      TextSpan(style: codeStyle.baseStyle, text: 'index'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ']);'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a                '),
+      TextSpan(style: codeStyle.keywordStyle, text: 'return'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'ListTile'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'title'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.classStyle, text: 'Text'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'title'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '));'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a              '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '},'),
+      TextSpan(
+          style: codeStyle.baseStyle, text: '\u000a              childCount'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' listCount'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ','),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a            '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a        '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '],'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a      '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a    '),
+      TextSpan(style: codeStyle.punctuationStyle, text: ');'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a  '),
+      TextSpan(style: codeStyle.punctuationStyle, text: '}'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '}'),
+      TextSpan(style: codeStyle.baseStyle, text: '\u000a\u000a'),
+    ]);
+  }
+
   static TextSpan cupertinoNavigationDemo(BuildContext context) {
     final CodeStyle codeStyle = CodeStyle.of(context);
     return TextSpan(children: [

gallery/gallery/lib/data/demos.dart

@@ -12,6 +12,7 @@ import 'package:gallery/demos/cupertino/cupertino_activity_indicator_demo.dart';
 import 'package:gallery/demos/cupertino/cupertino_alert_demo.dart';
 import 'package:gallery/demos/cupertino/cupertino_button_demo.dart';
 import 'package:gallery/demos/cupertino/cupertino_navigation_bar_demo.dart';
+import 'package:gallery/demos/cupertino/cupertino_refresh_demo.dart';
 import 'package:gallery/demos/cupertino/cupertino_segmented_control_demo.dart';
 import 'package:gallery/demos/cupertino/cupertino_slider_demo.dart';
 import 'package:gallery/demos/cupertino/cupertino_switch_demo.dart';
@@ -673,6 +674,24 @@ List<GalleryDemo> cupertinoDemos(BuildContext context) {
         ),
       ],
     ),
+    GalleryDemo(
+      title: GalleryLocalizations.of(context).demoCupertinoPullToRefreshTitle,
+      icon: GalleryIcons.cupertinoPullToRefresh,
+      subtitle:
+          GalleryLocalizations.of(context).demoCupertinoPullToRefreshSubtitle,
+      configurations: [
+        GalleryDemoConfiguration(
+          title:
+              GalleryLocalizations.of(context).demoCupertinoPullToRefreshTitle,
+          description: GalleryLocalizations.of(context)
+              .demoCupertinoPullToRefreshDescription,
+          documentationUrl:
+              'https://api.flutter.dev/flutter/cupertino/CupertinoSliverRefreshControl-class.html',
+          buildRoute: (_) => CupertinoRefreshControlDemo(),
+          code: CodeSegments.cupertinoRefreshDemo,
+        ),
+      ],
+    ),
     GalleryDemo(
       title:
           GalleryLocalizations.of(context).demoCupertinoSegmentedControlTitle,

gallery/gallery/lib/demos/cupertino/cupertino_refresh_demo.dart

@@ -0,0 +1,74 @@
+// Copyright 2019 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:math' show Random;
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:gallery/l10n/gallery_localizations.dart';
+
+// BEGIN cupertinoRefreshDemo
+
+class CupertinoRefreshControlDemo extends StatefulWidget {
+  @override
+  _CupertinoRefreshControlDemoState createState() =>
+      _CupertinoRefreshControlDemoState();
+}
+
+class _CupertinoRefreshControlDemoState
+    extends State<CupertinoRefreshControlDemo> {
+  static const listCount = 20;
+  var randomList = List<int>.generate(listCount, (i) => i + 1);
+
+  void _shuffleList() => randomList.shuffle(Random());
+
+  @override
+  Widget build(BuildContext context) {
+    return CupertinoPageScaffold(
+      child: CustomScrollView(
+        // If left unspecified, the [CustomScrollView] appends an
+        // [AlwaysScrollableScrollPhysics]. Behind the scene, the ScrollableState
+        // will attach that [AlwaysScrollableScrollPhysics] to the output of
+        // [ScrollConfiguration.of] which will be a [ClampingScrollPhysics]
+        // on Android.
+        // To demonstrate the iOS behavior in this demo and to ensure that the list
+        // always scrolls, we specifically use a [BouncingScrollPhysics] combined
+        // with a [AlwaysScrollableScrollPhysics]
+        physics: const BouncingScrollPhysics(
+          parent: AlwaysScrollableScrollPhysics(),
+        ),
+        slivers: [
+          CupertinoSliverNavigationBar(
+            automaticallyImplyLeading: false,
+            largeTitle: Text(
+              GalleryLocalizations.of(context).demoCupertinoPullToRefreshTitle,
+            ),
+          ),
+          CupertinoSliverRefreshControl(
+            onRefresh: () {
+              return Future<void>.delayed(const Duration(seconds: 1))
+                ..then<void>((_) {
+                  if (mounted) {
+                    setState(() => _shuffleList());
+                  }
+                });
+            },
+          ),
+          SliverList(
+            delegate: SliverChildBuilderDelegate(
+              (context, index) {
+                final title = GalleryLocalizations.of(context)
+                    .starterAppDrawerItem(randomList[index]);
+                return ListTile(title: Text(title));
+              },
+              childCount: listCount,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+// END

gallery/gallery/lib/l10n/gallery_localizations.dart

@@ -1681,6 +1681,28 @@ class GalleryLocalizations {
         desc: r'Title for the cupertino navigation bar component demo.');
   }
 
+  String get demoCupertinoPullToRefreshDescription {
+    return Intl.message(
+        r'A widget implementing the iOS-style pull to refresh content control.',
+        locale: _localeName,
+        name: 'demoCupertinoPullToRefreshDescription',
+        desc: r'Description for the cupertino pull-to-refresh component demo.');
+  }
+
+  String get demoCupertinoPullToRefreshSubtitle {
+    return Intl.message(r'iOS-style pull to refresh control',
+        locale: _localeName,
+        name: 'demoCupertinoPullToRefreshSubtitle',
+        desc: r'Subtitle for the cupertino pull-to-refresh component demo.');
+  }
+
+  String get demoCupertinoPullToRefreshTitle {
+    return Intl.message(r'Pull To Refresh',
+        locale: _localeName,
+        name: 'demoCupertinoPullToRefreshTitle',
+        desc: r'Title for the cupertino pull-to-refresh component demo.');
+  }
+
   String get demoCupertinoSegmentedControlDescription {
     return Intl.message(
         r'Used to select between a number of mutually exclusive options. When one option in the segmented control is selected, the other options in the segmented control cease to be selected.',

gallery/gallery/lib/l10n/intl_en_US.arb

@@ -887,6 +887,18 @@
   "@demoCupertinoNavigationBarDescription": {
     "description": "Description for the cupertino navigation bar component demo."
   },
+  "demoCupertinoPullToRefreshTitle": "Pull To Refresh",
+  "@demoCupertinoPullToRefreshTitle": {
+    "description": "Title for the cupertino pull-to-refresh component demo."
+  },
+  "demoCupertinoPullToRefreshSubtitle": "iOS-style pull to refresh control",
+  "@demoCupertinoPullToRefreshSubtitle": {
+    "description": "Subtitle for the cupertino pull-to-refresh component demo."
+  },
+  "demoCupertinoPullToRefreshDescription": "A widget implementing the iOS-style pull to refresh content control.",
+  "@demoCupertinoPullToRefreshDescription": {
+    "description": "Description for the cupertino pull-to-refresh component demo."
+  },
   "demoCupertinoSegmentedControlTitle": "Segmented Control",
   "@demoCupertinoSegmentedControlTitle": {
     "description": "Title for the cupertino segmented control component demo."

gallery/gallery/lib/l10n/intl_en_US.xml

@@ -841,6 +841,18 @@
     name="demoCupertinoNavigationBarDescription"
     description="Description for the cupertino navigation bar component demo."
     >An iOS-styled navigation bar. The navigation bar is a toolbar that minimally consists of a page title, in the middle of the toolbar.</string>
+  <string
+    name="demoCupertinoPullToRefreshTitle"
+    description="Title for the cupertino pull-to-refresh component demo."
+    >Pull To Refresh</string>
+  <string
+    name="demoCupertinoPullToRefreshSubtitle"
+    description="Subtitle for the cupertino pull-to-refresh component demo."
+    >iOS-style pull to refresh control</string>
+  <string
+    name="demoCupertinoPullToRefreshDescription"
+    description="Description for the cupertino pull-to-refresh component demo."
+    >A widget implementing the iOS-style pull to refresh content control.</string>
   <string
     name="demoCupertinoSegmentedControlTitle"
     description="Title for the cupertino segmented control component demo."

gallery/gallery/lib/l10n/messages_en_US.dart

@@ -442,6 +442,14 @@ class MessageLookup extends MessageLookupByLibrary {
             MessageLookupByLibrary.simpleMessage("iOS-style navigation bar"),
         "demoCupertinoNavigationBarTitle":
             MessageLookupByLibrary.simpleMessage("Navigation Bar"),
+        "demoCupertinoPullToRefreshDescription":
+            MessageLookupByLibrary.simpleMessage(
+                "A widget implementing the iOS-style pull to refresh content control."),
+        "demoCupertinoPullToRefreshSubtitle":
+            MessageLookupByLibrary.simpleMessage(
+                "iOS-style pull to refresh control"),
+        "demoCupertinoPullToRefreshTitle":
+            MessageLookupByLibrary.simpleMessage("Pull To Refresh"),
         "demoCupertinoSegmentedControlDescription":
             MessageLookupByLibrary.simpleMessage(
                 "Used to select between a number of mutually exclusive options. When one option in the segmented control is selected, the other options in the segmented control cease to be selected."),