CupertinoActionSheet (#19232)

Adding CupertinoActionSheet, showCupertinoModalPopup

packages/flutter/lib/cupertino.dart

@@ -7,6 +7,7 @@
 /// To use, import `package:flutter/cupertino.dart`.
 library cupertino;
 
+export 'src/cupertino/action_sheet.dart';
 export 'src/cupertino/activity_indicator.dart';
 export 'src/cupertino/app.dart';
 export 'src/cupertino/bottom_tab_bar.dart';

packages/flutter/lib/src/cupertino/route.dart

@@ -14,6 +14,9 @@ const double _kMinFlingVelocity = 1.0; // Screen widths per second.
 // Barrier color for a Cupertino modal barrier.
 const Color _kModalBarrierColor = Color(0x6604040F);
 
+// The duration of the transition used when a modal popup is shown.
+const Duration _kModalPopupTransitionDuration = Duration(milliseconds: 335);
+
 // Offset from offscreen to the right to fully on screen.
 final Tween<Offset> _kRightMiddleTween = new Tween<Offset>(
   begin: const Offset(1.0, 0.0),
@@ -715,6 +718,102 @@ class _CupertinoEdgeShadowPainter extends BoxPainter {
   }
 }
 
+class _CupertinoModalPopupRoute<T> extends PopupRoute<T> {
+  _CupertinoModalPopupRoute({
+    this.builder,
+    this.barrierLabel,
+    RouteSettings settings,
+  }) : super(settings: settings);
+
+  final WidgetBuilder builder;
+
+  @override
+  final String barrierLabel;
+
+  @override
+  Color get barrierColor => _kModalBarrierColor;
+
+  @override
+  bool get barrierDismissible => true;
+
+  @override
+  bool get semanticsDismissible => false;
+
+  @override
+  Duration get transitionDuration => _kModalPopupTransitionDuration;
+
+  Animation<double> _animation;
+
+  Tween<Offset> _offsetTween;
+
+  @override
+  Animation<double> createAnimation() {
+    assert(_animation == null);
+    _animation = new CurvedAnimation(
+      parent: super.createAnimation(),
+      curve: Curves.ease,
+      reverseCurve: Curves.ease.flipped,
+    );
+    _offsetTween = new Tween<Offset>(
+      begin: const Offset(0.0, 1.0),
+      end: const Offset(0.0, 0.0),
+    );
+    return _animation;
+  }
+
+  @override
+  Widget buildPage(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
+    return builder(context);
+  }
+
+  @override
+  Widget buildTransitions(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
+    return new Align(
+      alignment: Alignment.bottomCenter,
+      child: new FractionalTranslation(
+        translation: _offsetTween.evaluate(_animation),
+        child: child,
+      ),
+    );
+  }
+}
+
+/// Shows a modal iOS-style popup that slides up from the bottom of the screen.
+///
+/// Such a popup is an alternative to a menu or a dialog and prevents the user
+/// from interacting with the rest of the app.
+///
+/// The `context` argument is used to look up the [Navigator] for the popup.
+/// It is only used when the method is called. Its corresponding widget can be
+/// safely removed from the tree before the popup is closed.
+///
+/// The `builder` argument typically builds a [CupertinoActionSheet] widget.
+/// Content below the widget is dimmed with a [ModalBarrier]. The widget built
+/// by the `builder` does not share a context with the location that
+/// `showCupertinoModalPopup` is originally called from. Use a
+/// [StatefulBuilder] or a custom [StatefulWidget] if the widget needs to
+/// update dynamically.
+///
+/// Returns a `Future` that resolves to the value that was passed to
+/// [Navigator.pop] when the popup was closed.
+///
+/// See also:
+///
+///  * [ActionSheet], which is the widget usually returned by the `builder`
+///    argument to [showCupertinoModalPopup].
+///  * <https://developer.apple.com/design/human-interface-guidelines/ios/views/action-sheets/>
+Future<T> showCupertinoModalPopup<T>({
+  @required BuildContext context,
+  @required WidgetBuilder builder,
+}) {
+  return Navigator.of(context, rootNavigator: true).push(
+    new _CupertinoModalPopupRoute<T>(
+      builder: builder,
+      barrierLabel: 'Dismiss',
+    ),
+  );
+}
+
 Widget _buildCupertinoDialogTransitions(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
   final CurvedAnimation fadeAnimation = new CurvedAnimation(
     parent: animation,

packages/flutter/lib/src/painting/box_decoration.dart

@@ -70,6 +70,7 @@ class BoxDecoration extends Decoration {
   ///   [BoxShape.circle].
   /// * If [boxShadow] is null, this decoration does not paint a shadow.
   /// * If [gradient] is null, this decoration does not paint gradients.
+  /// * If [backgroundBlendMode] is null, this decoration paints with [BlendMode.srcOver]
   ///
   /// The [shape] argument must not be null.
   const BoxDecoration({
@@ -79,13 +80,20 @@ class BoxDecoration extends Decoration {
     this.borderRadius,
     this.boxShadow,
     this.gradient,
+    this.backgroundBlendMode,
     this.shape = BoxShape.rectangle,
-  }) : assert(shape != null);
+  }) : assert(shape != null),
+       // TODO(mattcarroll): Use "backgroundBlendMode == null" when Dart #31140 is in.
+       assert(
+       identical(backgroundBlendMode, null) || color != null || gradient != null,
+       'backgroundBlendMode applies to BoxDecoration\'s background color or'
+           'gradient, but no color or gradient were provided.'
+       );
 
   @override
   bool debugAssertIsValid() {
     assert(shape != BoxShape.circle ||
-           borderRadius == null); // Can't have a border radius if you're a circle.
+          borderRadius == null); // Can't have a border radius if you're a circle.
     return super.debugAssertIsValid();
   }
 
@@ -136,6 +144,14 @@ class BoxDecoration extends Decoration {
   /// The [gradient] is drawn under the [image].
   final Gradient gradient;
 
+  /// The blend mode applied to the [color] or [gradient] background of the box.
+  ///
+  /// If no [backgroundBlendMode] is provided, then the default painting blend
+  /// mode is used.
+  ///
+  /// If no [color] or [gradient] is provided, then blend mode has no impact.
+  final BlendMode backgroundBlendMode;
+
   /// The shape to fill the background [color], [gradient], and [image] into and
   /// to cast as the [boxShadow].
   ///
@@ -332,6 +348,8 @@ class _BoxDecorationPainter extends BoxPainter {
     if (_cachedBackgroundPaint == null ||
         (_decoration.gradient != null && _rectForCachedBackgroundPaint != rect)) {
       final Paint paint = new Paint();
+      if (_decoration.backgroundBlendMode != null)
+        paint.blendMode = _decoration.backgroundBlendMode;
       if (_decoration.color != null)
         paint.color = _decoration.color;
       if (_decoration.gradient != null) {

packages/flutter/lib/src/widgets/modal_barrier.dart

@@ -33,6 +33,7 @@ class ModalBarrier extends StatelessWidget {
     this.color,
     this.dismissible = true,
     this.semanticsLabel,
+    this.barrierSemanticsDismissible = true,
   }) : super(key: key);
 
   /// If non-null, fill the barrier with this color.
@@ -51,6 +52,13 @@ class ModalBarrier extends StatelessWidget {
   ///    [ModalBarrier] built by [ModalRoute] pages.
   final bool dismissible;
 
+  /// Whether the modal barrier semantics are included in the semantics tree.
+  ///
+  /// See also:
+  ///  * [ModalRoute.semanticsDismissible], which controls this property for
+  ///    the [ModalBarrier] built by [ModalRoute] pages.
+  final bool barrierSemanticsDismissible;
+
   /// Semantics label used for the barrier if it is [dismissable].
   ///
   /// The semantics label is read out by accessibility tools (e.g. TalkBack
@@ -66,10 +74,12 @@ class ModalBarrier extends StatelessWidget {
   Widget build(BuildContext context) {
     assert(!dismissible || semanticsLabel == null || debugCheckHasDirectionality(context));
     final bool semanticsDismissible = dismissible && defaultTargetPlatform != TargetPlatform.android;
+    final bool modalBarrierSemanticsDismissible = barrierSemanticsDismissible ?? semanticsDismissible;
     return new BlockSemantics(
       child: new ExcludeSemantics(
-        // On Android, the back button is used to dismiss a modal.
+        // On Android, the back button is used to dismiss a modal. On iOS, some
-        excluding: !semanticsDismissible,
+        // modal barriers are not dismissible in accessibility mode.
+        excluding: !semanticsDismissible || !modalBarrierSemanticsDismissible,
         child: new GestureDetector(
           onTapDown: (TapDownDetails details) {
             if (dismissible)
@@ -117,6 +127,7 @@ class AnimatedModalBarrier extends AnimatedWidget {
     Animation<Color> color,
     this.dismissible = true,
     this.semanticsLabel,
+    this.barrierSemanticsDismissible,
   }) : super(key: key, listenable: color);
 
   /// If non-null, fill the barrier with this color.
@@ -145,12 +156,20 @@ class AnimatedModalBarrier extends AnimatedWidget {
   ///    [ModalBarrier] built by [ModalRoute] pages.
   final String semanticsLabel;
 
+  /// Whether the modal barrier semantics are included in the semantics tree.
+  ///
+  /// See also:
+  ///  * [ModalRoute.semanticsDismissible], which controls this property for
+  ///    the [ModalBarrier] built by [ModalRoute] pages.
+  final bool barrierSemanticsDismissible;
+
   @override
   Widget build(BuildContext context) {
     return new ModalBarrier(
       color: color?.value,
       dismissible: dismissible,
       semanticsLabel: semanticsLabel,
+      barrierSemanticsDismissible: barrierSemanticsDismissible,
     );
   }
 }

packages/flutter/lib/src/widgets/routes.dart

@@ -898,6 +898,21 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   ///  * [ModalBarrier], the widget that implements this feature.
   bool get barrierDismissible;
 
+  /// Whether the semantics of the modal barrier are included in the
+  /// semantics tree.
+  ///
+  /// The modal barrier is the scrim that is rendered behind each route, which
+  /// generally prevents the user from interacting with the route below the
+  /// current route, and normally partially obscures such routes.
+  ///
+  /// If [semanticsDismissible] is true, then modal barrier semantics are
+  /// included in the semantics tree.
+  ///
+  /// If [semanticsDismissible] is false, then modal barrier semantics are
+  /// excluded from the the semantics tree and tapping on the modal barrier
+  /// has no effect.
+  bool get semanticsDismissible => true;
+
   /// The color to use for the modal barrier. If this is null, the barrier will
   /// be transparent.
   ///
@@ -1173,11 +1188,13 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
         color: color,
         dismissible: barrierDismissible, // changedInternalState is called if this updates
         semanticsLabel: barrierLabel, // changedInternalState is called if this updates
+        barrierSemanticsDismissible: semanticsDismissible,
       );
     } else {
       barrier = new ModalBarrier(
         dismissible: barrierDismissible, // changedInternalState is called if this updates
         semanticsLabel: barrierLabel, // changedInternalState is called if this updates
+        barrierSemanticsDismissible: semanticsDismissible,
       );
     }
     return new IgnorePointer(

packages/flutter/test/cupertino/action_sheet_test.dart

@@ -0,0 +1,967 @@
+// Copyright 2018 The Chromium Authors. 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/cupertino.dart';
+import 'package:flutter/widgets.dart';
+
+import 'package:flutter_test/flutter_test.dart';
+
+import '../widgets/semantics_tester.dart';
+
+void main() {
+  testWidgets('Verify that a tap on modal barrier dismisses an action sheet',
+          (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        const CupertinoActionSheet(
+          title: Text('Action Sheet'),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(find.text('Action Sheet'), findsOneWidget);
+
+    await tester.tapAt(const Offset(20.0, 20.0));
+    await tester.pump();
+    expect(find.text('Action Sheet'), findsNothing);
+  });
+
+  testWidgets('Verify that a tap on title section (not buttons) does not dismiss an action sheet',
+          (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        const CupertinoActionSheet(
+          title: Text('Action Sheet'),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(find.text('Action Sheet'), findsOneWidget);
+
+    await tester.tap(find.text('Action Sheet'));
+    await tester.pump();
+    expect(find.text('Action Sheet'), findsOneWidget);
+  });
+
+  testWidgets('Action sheet destructive text style', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      boilerplate(
+        new CupertinoActionSheetAction(
+          isDestructiveAction: true,
+          child: const Text('Ok'),
+          onPressed: () {},
+        ),
+      ),
+    );
+
+    final DefaultTextStyle widget = tester.widget(find.widgetWithText(DefaultTextStyle, 'Ok'));
+
+    expect(widget.style.color, CupertinoColors.destructiveRed);
+  });
+
+  testWidgets('Action sheet default text style', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      boilerplate(
+        new CupertinoActionSheetAction(
+          isDefaultAction: true,
+          child: const Text('Ok'),
+          onPressed: () {},
+        ),
+      ),
+    );
+
+    final DefaultTextStyle widget = tester.widget(find.widgetWithText(DefaultTextStyle, 'Ok'));
+
+    expect(widget.style.fontWeight, equals(FontWeight.w600));
+  });
+
+  testWidgets('Action sheet text styles are correct when both title and message are included',
+          (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        const CupertinoActionSheet(
+          title: Text('Action Sheet'),
+          message: Text('An action sheet')
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    final DefaultTextStyle titleStyle = tester.firstWidget(find.widgetWithText(DefaultTextStyle,
+        'Action Sheet'));
+    final DefaultTextStyle messageStyle = tester.firstWidget(find.widgetWithText(DefaultTextStyle,
+        'An action sheet'));
+
+    expect(titleStyle.style.fontWeight, FontWeight.w600);
+    expect(messageStyle.style.fontWeight, FontWeight.w400);
+  });
+
+  testWidgets('Action sheet text styles are correct when title but no message is included',
+          (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        const CupertinoActionSheet(
+          title: Text('Action Sheet'),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    final DefaultTextStyle titleStyle = tester.firstWidget(find.widgetWithText(DefaultTextStyle,
+        'Action Sheet'));
+
+    expect(titleStyle.style.fontWeight, FontWeight.w400);
+  });
+
+  testWidgets('Action sheet text styles are correct when message but no title is included',
+          (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        const CupertinoActionSheet(
+          message: Text('An action sheet'),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    final DefaultTextStyle messageStyle = tester.firstWidget(find.widgetWithText(DefaultTextStyle,
+        'An action sheet'));
+
+    expect(messageStyle.style.fontWeight, FontWeight.w600);
+  });
+
+  testWidgets('Content section but no actions', (WidgetTester tester) async {
+    final ScrollController scrollController = new ScrollController();
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: const Text('The message.'),
+          messageScrollController: scrollController,
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    // Content section should be at the bottom left of action sheet
+    // (minus padding).
+    expect(tester.getBottomLeft(find.byType(ClipRRect)),
+        tester.getBottomLeft(find.byType(CupertinoActionSheet)) - const Offset(-8.0, 10.0));
+
+    // Check that the dialog size is the same as the content section size
+    // (minus padding).
+    expect(
+      tester.getSize(find.byType(ClipRRect)).height,
+      tester.getSize(find.byType(CupertinoActionSheet)).height  - 20.0,
+    );
+
+    expect(
+      tester.getSize(find.byType(ClipRRect)).width,
+      tester.getSize(find.byType(CupertinoActionSheet)).width - 16.0,
+    );
+  });
+
+  testWidgets('Actions but no content section', (WidgetTester tester) async {
+    final ScrollController actionScrollController = new ScrollController();
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+          ],
+          actionScrollController: actionScrollController,
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    final Finder finder = find.byElementPredicate(
+      (Element element) {
+        return element.widget.runtimeType.toString() == '_CupertinoAlertActionSection';
+      },
+    );
+
+    // Check that the title/message section is not displayed (action section is
+    // at the top of the action sheet + padding).
+    expect(tester.getTopLeft(finder),
+        tester.getTopLeft(find.byType(CupertinoActionSheet)) + const Offset(8.0, 10.0));
+
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)) + const Offset(8.0, 10.0),
+        tester.getTopLeft(find.widgetWithText(CupertinoActionSheetAction, 'One')));
+    expect(tester.getBottomLeft(find.byType(CupertinoActionSheet)) + const Offset(8.0, -10.0),
+        tester.getBottomLeft(find.widgetWithText(CupertinoActionSheetAction, 'Two')));
+  });
+
+  testWidgets('Action section is scrollable', (WidgetTester tester) async {
+    final ScrollController actionScrollController = new ScrollController();
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new Builder(builder: (BuildContext context) {
+          return new MediaQuery(
+            data: MediaQuery.of(context).copyWith(textScaleFactor: 3.0),
+            child: new CupertinoActionSheet(
+              title: const Text('The title'),
+              message: const Text('The message.'),
+              actions: <Widget>[
+                new CupertinoActionSheetAction(
+                  child: const Text('One'),
+                  onPressed: () {},
+                ),
+                new CupertinoActionSheetAction(
+                  child: const Text('Two'),
+                  onPressed: () {},
+                ),
+                new CupertinoActionSheetAction(
+                  child: const Text('Three'),
+                  onPressed: () {},
+                ),
+                new CupertinoActionSheetAction(
+                  child: const Text('Four'),
+                  onPressed: () {},
+                ),
+                new CupertinoActionSheetAction(
+                  child: const Text('Five'),
+                  onPressed: () {},
+                ),
+              ],
+              actionScrollController: actionScrollController,
+            ),
+          );
+        }),
+      )
+    );
+
+    await tester.tap(find.text('Go'));
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    // Check that the action buttons list is scrollable.
+    expect(actionScrollController.offset, 0.0);
+    actionScrollController.jumpTo(100.0);
+    expect(actionScrollController.offset, 100.0);
+    actionScrollController.jumpTo(0.0);
+
+    // Check that the action buttons are aligned vertically.
+    expect(tester.getCenter(find.widgetWithText(CupertinoActionSheetAction, 'One')).dx, equals(400.0));
+    expect(tester.getCenter(find.widgetWithText(CupertinoActionSheetAction, 'Two')).dx, equals(400.0));
+    expect(tester.getCenter(find.widgetWithText(CupertinoActionSheetAction, 'Three')).dx, equals(400.0));
+    expect(tester.getCenter(find.widgetWithText(CupertinoActionSheetAction, 'Four')).dx, equals(400.0));
+    expect(tester.getCenter(find.widgetWithText(CupertinoActionSheetAction, 'Five')).dx, equals(400.0));
+
+    // Check that the action buttons are the correct heights.
+    expect(tester.getSize(find.widgetWithText(CupertinoActionSheetAction, 'One')).height, equals(92.0));
+    expect(tester.getSize(find.widgetWithText(CupertinoActionSheetAction, 'Two')).height, equals(92.0));
+    expect(tester.getSize(find.widgetWithText(CupertinoActionSheetAction, 'Three')).height, equals(92.0));
+    expect(tester.getSize(find.widgetWithText(CupertinoActionSheetAction, 'Four')).height, equals(92.0));
+    expect(tester.getSize(find.widgetWithText(CupertinoActionSheetAction, 'Five')).height, equals(92.0));
+  });
+
+  testWidgets('Content section is scrollable', (WidgetTester tester) async {
+    final ScrollController messageScrollController = new ScrollController();
+    double screenHeight;
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new Builder(builder: (BuildContext context) {
+          screenHeight = MediaQuery.of(context).size.height;
+          return new MediaQuery(
+            data: MediaQuery.of(context).copyWith(textScaleFactor: 3.0),
+            child: new CupertinoActionSheet(
+              title: const Text('The title'),
+              message: new Text('Very long content' * 200),
+              actions: <Widget>[
+                new CupertinoActionSheetAction(
+                  child: const Text('One'),
+                  onPressed: () {},
+                ),
+                new CupertinoActionSheetAction(
+                  child: const Text('Two'),
+                  onPressed: () {},
+                ),
+              ],
+              messageScrollController: messageScrollController,
+            ),
+          );
+        }),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(messageScrollController.offset, 0.0);
+    messageScrollController.jumpTo(100.0);
+    expect(messageScrollController.offset, 100.0);
+    // Set the scroll position back to zero.
+    messageScrollController.jumpTo(0.0);
+
+    // Expect the action sheet to take all available height.
+    expect(tester.getSize(find.byType(CupertinoActionSheet)).height, screenHeight);
+  });
+
+  testWidgets('Tap on button calls onPressed', (WidgetTester tester) async {
+    bool wasPressed = false;
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new Builder(builder: (BuildContext context) {
+          return new CupertinoActionSheet(
+            actions: <Widget>[
+              new CupertinoActionSheetAction(
+                child: const Text('One'),
+                onPressed: () {
+                  wasPressed = true;
+                  Navigator.pop(context);
+                },
+              ),
+            ],
+          );
+        }),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    expect(wasPressed, isFalse);
+
+    await tester.tap(find.text('One'));
+
+    expect(wasPressed, isTrue);
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    expect(find.text('One'), findsNothing);
+  });
+
+  testWidgets('Action sheet width is correct when given infinite horizontal space',
+          (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new Row(
+          children: <Widget>[
+            new CupertinoActionSheet(
+              actions: <Widget>[
+                new CupertinoActionSheetAction(
+                  child: const Text('One'),
+                  onPressed: () {},
+                ),
+                new CupertinoActionSheetAction(
+                  child: const Text('Two'),
+                  onPressed: () {},
+                ),
+              ],
+            ),
+          ],
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(tester.getSize(find.byType(CupertinoActionSheet)).width, 600.0);
+  });
+
+  testWidgets('Action sheet height is correct when given infinite vertical space',
+          (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new Column(
+          children: <Widget>[
+            new CupertinoActionSheet(
+              actions: <Widget>[
+                new CupertinoActionSheetAction(
+                  child: const Text('One'),
+                  onPressed: () {},
+                ),
+                new CupertinoActionSheetAction(
+                  child: const Text('Two'),
+                  onPressed: () {},
+                ),
+              ],
+            ),
+          ],
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(tester.getSize(find.byType(CupertinoActionSheet)).height,
+        moreOrLessEquals(132.33333333333334));
+  });
+
+  testWidgets('1 action button with cancel button', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: new Text('Very long content' * 200),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+          ],
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    // Action section is size of one action button.
+    expect(findScrollableActionsSectionRenderBox(tester).size.height, 56.0);
+  });
+
+  testWidgets('2 action buttons with cancel button', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: new Text('Very long content' * 200),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+          ],
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(findScrollableActionsSectionRenderBox(tester).size.height,
+        moreOrLessEquals(112.33333333333331));
+  });
+
+  testWidgets('3 action buttons with cancel button', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: new Text('Very long content' * 200),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Three'),
+              onPressed: () {},
+            ),
+          ],
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(findScrollableActionsSectionRenderBox(tester).size.height,
+        moreOrLessEquals(168.66666666666669));
+  });
+
+  testWidgets('4+ action buttons with cancel button', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: new Text('Very long content' * 200),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Three'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Four'),
+              onPressed: () {},
+            ),
+          ],
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(findScrollableActionsSectionRenderBox(tester).size.height,
+        moreOrLessEquals(84.33333333333337));
+  });
+
+  testWidgets('1 action button without cancel button', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: new Text('Very long content' * 200),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+          ],
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(findScrollableActionsSectionRenderBox(tester).size.height, 56.0);
+  });
+
+  testWidgets('2+ action buttons without cancel button', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: new Text('Very long content' * 200),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+          ],
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(findScrollableActionsSectionRenderBox(tester).size.height,
+        moreOrLessEquals(84.33333333333337));
+  });
+
+  testWidgets('Action sheet with just cancel button is correct', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: (){},
+          ),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    // Height should be cancel button height + padding
+    expect(tester.getSize(find.byType(CupertinoActionSheet)).height, 76.0);
+    expect(tester.getSize(find.byType(CupertinoActionSheet)).width, 600.0);
+  });
+
+  testWidgets('Cancel button tap calls onPressed', (WidgetTester tester) async {
+    bool wasPressed = false;
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new Builder(builder: (BuildContext context) {
+          return new CupertinoActionSheet(
+            cancelButton: new CupertinoActionSheetAction(
+              child: const Text('Cancel'),
+              onPressed: () {
+                wasPressed = true;
+                Navigator.pop(context);
+              },
+            ),
+          );
+        }),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    expect(wasPressed, isFalse);
+
+    await tester.tap(find.text('Cancel'));
+
+    expect(wasPressed, isTrue);
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    expect(find.text('Cancel'), findsNothing);
+  });
+
+  testWidgets('Layout is correct when cancel button is present', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: const Text('The message'),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+          ],
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    expect(tester.getBottomLeft(find.widgetWithText(CupertinoActionSheetAction, 'Cancel')).dy, 590.0);
+    expect(tester.getBottomLeft(find.widgetWithText(CupertinoActionSheetAction, 'One')).dy,
+        moreOrLessEquals(469.66666666666663));
+    expect(tester.getBottomLeft(find.widgetWithText(CupertinoActionSheetAction, 'Two')).dy, 526.0);
+  });
+
+  testWidgets('Enter/exit animation is correct', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: const Text('The message'),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+          ],
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+
+    // Enter animation
+    await tester.tap(find.text('Go'));
+
+    await tester.pump();
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, 600.0);
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(530.9, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(426.7, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(365.0, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(334.0, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(321.0, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(319.3, 0.1));
+
+    // Action sheet has reached final height
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(319.3, 0.1));
+
+    // Exit animation
+    await tester.tapAt(const Offset(20.0, 20.0));
+    await tester.pump();
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(319.3, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(388.4, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(492.6, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(554.2, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(585.2, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(598.2, 0.1));
+
+    // Action sheet has disappeared
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(find.byType(CupertinoActionSheet), findsNothing);
+  });
+
+  testWidgets('Modal barrier is pressed during transition', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: const Text('The message'),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+          ],
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+
+    // Enter animation
+    await tester.tap(find.text('Go'));
+
+    await tester.pump();
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, 600.0);
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(530.9, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(426.7, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(365.0, 0.1));
+
+    // Exit animation
+    await tester.tapAt(const Offset(20.0, 20.0));
+    await tester.pump(const Duration(milliseconds: 60));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(426.7, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, closeTo(530.9, 0.1));
+
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(tester.getTopLeft(find.byType(CupertinoActionSheet)).dy, 600.0);
+
+    // Action sheet has disappeared
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(find.byType(CupertinoActionSheet), findsNothing);
+  });
+
+
+  testWidgets('Action sheet semantics', (WidgetTester tester) async {
+    final SemanticsTester semantics = new SemanticsTester(tester);
+
+    await tester.pumpWidget(
+      createAppWithButtonThatLaunchesActionSheet(
+        new CupertinoActionSheet(
+          title: const Text('The title'),
+          message: const Text('The message'),
+          actions: <Widget>[
+            new CupertinoActionSheetAction(
+              child: const Text('One'),
+              onPressed: () {},
+            ),
+            new CupertinoActionSheetAction(
+              child: const Text('Two'),
+              onPressed: () {},
+            ),
+          ],
+          cancelButton: new CupertinoActionSheetAction(
+            child: const Text('Cancel'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+
+    await tester.tap(find.text('Go'));
+    await tester.pump();
+
+    expect(
+      semantics,
+      hasSemantics(
+        new TestSemantics.root(
+          children: <TestSemantics>[
+            new TestSemantics(
+              children: <TestSemantics>[
+                new TestSemantics(
+                  flags: <SemanticsFlag>[
+                    SemanticsFlag.scopesRoute,
+                    SemanticsFlag.namesRoute,
+                  ],
+                  label: 'Alert',
+                  children: <TestSemantics>[
+                    new TestSemantics(
+                      children: <TestSemantics>[
+                        new TestSemantics(
+                          label: 'The title',
+                        ),
+                        new TestSemantics(
+                          label: 'The message',
+                        ),
+                      ],
+                    ),
+                    new TestSemantics(
+                      children: <TestSemantics>[
+                        new TestSemantics(
+                          flags: <SemanticsFlag>[
+                            SemanticsFlag.isButton,
+                          ],
+                          actions: <SemanticsAction>[
+                            SemanticsAction.tap,
+                          ],
+                          label: 'One',
+                        ),
+                        new TestSemantics(
+                          flags: <SemanticsFlag>[
+                            SemanticsFlag.isButton,
+                          ],
+                          actions: <SemanticsAction>[
+                            SemanticsAction.tap,
+                          ],
+                          label: 'Two',
+                        ),
+                      ],
+                    ),
+                    new TestSemantics(
+                      flags: <SemanticsFlag>[
+                        SemanticsFlag.isButton,
+                      ],
+                      actions: <SemanticsAction>[
+                        SemanticsAction.tap,
+                      ],
+                      label: 'Cancel',
+                    )
+                  ],
+                ),
+              ],
+            ),
+          ],
+        ),
+        ignoreId: true,
+        ignoreRect: true,
+        ignoreTransform: true,
+      ),
+    );
+
+    semantics.dispose();
+  });
+}
+
+RenderBox findScrollableActionsSectionRenderBox(WidgetTester tester) {
+  final RenderObject actionsSection = tester.renderObject(find.byElementPredicate(
+    (Element element) {
+      return element.widget.runtimeType.toString() == '_CupertinoAlertActionSection';
+    }),
+  );
+  assert(actionsSection is RenderBox);
+  return actionsSection;
+}
+
+Widget createAppWithButtonThatLaunchesActionSheet(Widget actionSheet) {
+  return new CupertinoApp(
+    home: new Center(
+      child: new Builder(builder: (BuildContext context) {
+        return new CupertinoButton(
+          onPressed: () {
+            showCupertinoModalPopup<void>(
+              context: context,
+              builder: (BuildContext context) {
+                return actionSheet;
+              },
+            );
+          },
+          child: const Text('Go'),
+        );
+      }),
+    ),
+  );
+}
+
+Widget boilerplate(Widget child) {
+  return new Directionality(
+    textDirection: TextDirection.ltr,
+    child: child,
+  );
+}