update slide_puzzle (#420)

* update slide_puzzle

* run createThumbnails before build-release grind task

* add license headers

web/slide_puzzle/lib/main.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import 'src/core/puzzle_animator.dart';
 import 'src/flutter.dart';
 import 'src/puzzle_home_state.dart';

web/slide_puzzle/lib/src/app_state.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import 'package:flutter/foundation.dart';
 
 import 'core/puzzle_proxy.dart';

web/slide_puzzle/lib/src/core/body.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. 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 Point;
 
 const zeroPoint = Point<double>(0, 0);

web/slide_puzzle/lib/src/core/point_int.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. 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' as math;
 
 class Point extends math.Point<int> {

web/slide_puzzle/lib/src/core/puzzle.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. 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:collection';
 import 'dart:convert';
 import 'dart:math' show Random, max;

web/slide_puzzle/lib/src/core/puzzle_animator.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. 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:async';
 import 'dart:math' show Point, Random;
 

web/slide_puzzle/lib/src/core/puzzle_proxy.dart

@@ -0,0 +1,25 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. 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 Point;
+
+enum PuzzleEvent { click, random, reset, noop }
+
+abstract class PuzzleProxy {
+  int get width;
+
+  int get height;
+
+  int get length;
+
+  bool get solved;
+
+  void clickOrShake(int tileValue);
+
+  int get tileCount;
+
+  Point<double> location(int index);
+
+  bool isCorrectPosition(int value);
+}

web/slide_puzzle/lib/src/core/puzzle_simple.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 part of 'puzzle.dart';
 
 class _PuzzleSimple extends Puzzle {

web/slide_puzzle/lib/src/core/puzzle_smart.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 part of 'puzzle.dart';
 
 mixin _SliceListMixin on ListMixin<int> {

web/slide_puzzle/lib/src/core/util.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 void requireArgument(bool truth, String argName, [String message]) {
   if (!truth) {
     if (message == null || message.isEmpty) {

web/slide_puzzle/lib/src/flutter.dart

@@ -0,0 +1,6 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+export 'package:flutter/material.dart';
+export 'package:flutter/scheduler.dart' show Ticker;

web/slide_puzzle/lib/src/puzzle_controls.dart

@@ -0,0 +1,17 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:flutter/foundation.dart';
+
+abstract class PuzzleControls implements Listenable {
+  void reset();
+
+  int get clickCount;
+
+  int get incorrectTiles;
+
+  bool get autoPlay;
+
+  void Function(bool newValue) get setAutoPlayFunction;
+}

web/slide_puzzle/lib/src/puzzle_flow_delegate.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import 'core/puzzle_proxy.dart';
 import 'flutter.dart';
 

web/slide_puzzle/lib/src/puzzle_home_state.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. 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:async';
 
 import 'package:provider/provider.dart';

web/slide_puzzle/lib/src/shared_theme.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import 'core/puzzle_proxy.dart';
 import 'flutter.dart';
 import 'puzzle_controls.dart';

web/slide_puzzle/lib/src/theme_plaster.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import 'core/puzzle_proxy.dart';
 import 'flutter.dart';
 import 'shared_theme.dart';

web/slide_puzzle/lib/src/theme_seattle.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import 'core/puzzle_proxy.dart';
 import 'flutter.dart';
 import 'shared_theme.dart';

web/slide_puzzle/lib/src/theme_simple.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import 'core/puzzle_proxy.dart';
 import 'flutter.dart';
 import 'shared_theme.dart';

web/slide_puzzle/lib/src/themes.dart

@@ -0,0 +1,13 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'theme_plaster.dart';
+import 'theme_seattle.dart';
+import 'theme_simple.dart';
+
+const themes = [
+  ThemeSimple(),
+  ThemeSeattle(),
+  ThemePlaster(),
+];

web/slide_puzzle/lib/src/value_tab_controller.dart

@@ -0,0 +1,92 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+class ValueTabController<T> extends StatefulWidget {
+  /// Creates a default tab controller for the given [child] widget.
+  const ValueTabController({
+    Key key,
+    @required this.child,
+    @required this.values,
+  }) : super(key: key);
+
+  /// The widget below this widget in the tree.
+  ///
+  /// Typically a [Scaffold] whose [AppBar] includes a [TabBar].
+  ///
+  /// {@macro flutter.widgets.child}
+  final Widget child;
+
+  final List<T> values;
+
+  /// The closest instance of this class that encloses the given context.
+  ///
+  /// Typical usage:
+  ///
+  /// ```dart
+  /// TabController controller = DefaultTabBarController.of(context);
+  /// ```
+  static TabController of(BuildContext context) {
+    final scope = context.inheritFromWidgetOfExactType(_ValueTabControllerScope)
+        as _ValueTabControllerScope;
+    return scope?.controller;
+  }
+
+  @override
+  _ValueTabControllerState<T> createState() => _ValueTabControllerState<T>();
+}
+
+class _ValueTabControllerState<T> extends State<ValueTabController<T>>
+    with SingleTickerProviderStateMixin {
+  final _notifier = ValueNotifier<T>(null);
+
+  TabController _controller;
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = TabController(
+      vsync: this,
+      length: widget.values.length,
+      initialIndex: 0,
+    );
+
+    _notifier.value = widget.values.first;
+
+    _controller.addListener(() {
+      _notifier.value = widget.values[_controller.index];
+    });
+  }
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) => _ValueTabControllerScope(
+        controller: _controller,
+        enabled: TickerMode.of(context),
+        child: ValueListenableProvider.value(
+          valueListenable: _notifier,
+          child: widget.child,
+        ),
+      );
+}
+
+class _ValueTabControllerScope extends InheritedWidget {
+  const _ValueTabControllerScope(
+      {Key key, this.controller, this.enabled, Widget child})
+      : super(key: key, child: child);
+
+  final TabController controller;
+  final bool enabled;
+
+  @override
+  bool updateShouldNotify(_ValueTabControllerScope old) =>
+      enabled != old.enabled || controller != old.controller;
+}

web/slide_puzzle/lib/src/widgets/decoration_image_plus.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 // ignore_for_file: omit_local_variable_types, annotate_overrides
 
 import 'dart:developer' as developer;

web/slide_puzzle/lib/src/widgets/material_interior_alt.dart

@@ -1,3 +1,7 @@
+// Copyright 2020, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import '../flutter.dart';
 
 // Copied from