Update cupertino demos in gallery (#43841)

examples/flutter_gallery/lib/demo/cupertino/cupertino_refresh_demo.dart

@@ -41,59 +41,53 @@ class _CupertinoRefreshControlDemoState extends State<CupertinoRefreshControlDem
     return DefaultTextStyle(
       style: CupertinoTheme.of(context).textTheme.textStyle,
       child: CupertinoPageScaffold(
-        child: DecoratedBox(
-          decoration: BoxDecoration(
-            color: CupertinoTheme.of(context).brightness == Brightness.light
-                ? CupertinoColors.extraLightBackgroundGray
-                : CupertinoColors.darkBackgroundGray,
-          ),
-          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: <Widget>[
-              CupertinoSliverNavigationBar(
-                largeTitle: const Text('Refresh'),
-                // We're specifying a back label here because the previous page
-                // is a Material page. CupertinoPageRoutes could auto-populate
-                // these back labels.
-                previousPageTitle: 'Cupertino',
-                trailing: CupertinoDemoDocumentationButton(CupertinoRefreshControlDemo.routeName),
-              ),
-              CupertinoSliverRefreshControl(
-                onRefresh: () {
-                  return Future<void>.delayed(const Duration(seconds: 2))
-                      ..then<void>((_) {
-                        if (mounted) {
-                          setState(() => repopulateList());
-                        }
-                      });
-                },
-              ),
-              SliverSafeArea(
-                top: false, // Top safe area is consumed by the navigation bar.
-                sliver: SliverList(
-                  delegate: SliverChildBuilderDelegate(
-                    (BuildContext context, int index) {
-                      return _ListItem(
-                        name: randomizedContacts[index][0],
-                        place: randomizedContacts[index][1],
-                        date: randomizedContacts[index][2],
-                        called: randomizedContacts[index][3] == 'true',
-                      );
-                    },
-                    childCount: 20,
-                  ),
+        backgroundColor: CupertinoColors.systemGroupedBackground,
+        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: <Widget>[
+            CupertinoSliverNavigationBar(
+              largeTitle: const Text('Refresh'),
+              // We're specifying a back label here because the previous page
+              // is a Material page. CupertinoPageRoutes could auto-populate
+              // these back labels.
+              previousPageTitle: 'Cupertino',
+              trailing: CupertinoDemoDocumentationButton(CupertinoRefreshControlDemo.routeName),
+            ),
+            CupertinoSliverRefreshControl(
+              onRefresh: () {
+                return Future<void>.delayed(const Duration(seconds: 2))
+                ..then<void>((_) {
+                    if (mounted) {
+                      setState(() => repopulateList());
+                    }
+                });
+              },
+            ),
+            SliverSafeArea(
+              top: false, // Top safe area is consumed by the navigation bar.
+              sliver: SliverList(
+                delegate: SliverChildBuilderDelegate(
+                  (BuildContext context, int index) {
+                    return _ListItem(
+                      name: randomizedContacts[index][0],
+                      place: randomizedContacts[index][1],
+                      date: randomizedContacts[index][2],
+                      called: randomizedContacts[index][3] == 'true',
+                    );
+                  },
+                  childCount: 20,
                 ),
               ),
-            ],
-          ),
+            ),
+          ],
         ),
       ),
     );
@@ -163,7 +157,7 @@ class _ListItem extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Container(
-      color: CupertinoTheme.of(context).scaffoldBackgroundColor,
+      color: CupertinoDynamicColor.resolve(CupertinoColors.systemBackground, context),
       height: 60.0,
       padding: const EdgeInsets.only(top: 9.0),
       child: Row(

examples/flutter_gallery/lib/demo/cupertino/cupertino_segmented_control_demo.dart

@@ -46,7 +46,13 @@ class _CupertinoSegmentedControlDemoState extends State<CupertinoSegmentedContro
     ),
   };
 
-  int sharedValue = 0;
+  int currentSegment = 0;
+
+  void onValueChanged(int newValue) {
+    setState(() {
+      currentSegment = newValue;
+    });
+  }
 
   @override
   Widget build(BuildContext context) {
@@ -60,23 +66,28 @@ class _CupertinoSegmentedControlDemoState extends State<CupertinoSegmentedContro
         trailing: CupertinoDemoDocumentationButton(CupertinoSegmentedControlDemo.routeName),
       ),
       child: DefaultTextStyle(
-        style: CupertinoTheme.of(context).textTheme.textStyle,
+        style: CupertinoTheme.of(context).textTheme.textStyle.copyWith(fontSize: 13),
         child: SafeArea(
           child: Column(
             children: <Widget>[
-              const Padding(
-                padding: EdgeInsets.all(16.0),
-              ),
+              const Padding(padding: EdgeInsets.all(16.0)),
               SizedBox(
                 width: 500.0,
                 child: CupertinoSegmentedControl<int>(
                   children: children,
-                  onValueChanged: (int newValue) {
-                    setState(() {
-                      sharedValue = newValue;
-                    });
-                  },
-                  groupValue: sharedValue,
+                  onValueChanged: onValueChanged,
+                  groupValue: currentSegment,
+                ),
+              ),
+              SizedBox(
+                width: 500,
+                child: Padding(
+                  padding: const EdgeInsets.all(16.0),
+                  child: CupertinoSlidingSegmentedControl<int>(
+                    children: children,
+                    onValueChanged: onValueChanged,
+                    groupValue: currentSegment,
+                  ),
                 ),
               ),
               Expanded(
@@ -85,36 +96,43 @@ class _CupertinoSegmentedControlDemoState extends State<CupertinoSegmentedContro
                     vertical: 32.0,
                     horizontal: 16.0,
                   ),
-                  child: Container(
-                    padding: const EdgeInsets.symmetric(
-                      vertical: 64.0,
-                      horizontal: 16.0,
-                    ),
-                    decoration: BoxDecoration(
-                      color: CupertinoTheme.of(context).scaffoldBackgroundColor,
-                      borderRadius: BorderRadius.circular(3.0),
-                      boxShadow: const <BoxShadow>[
-                        BoxShadow(
-                          offset: Offset(0.0, 3.0),
-                          blurRadius: 5.0,
-                          spreadRadius: -1.0,
-                          color: _kKeyUmbraOpacity,
-                        ),
-                        BoxShadow(
-                          offset: Offset(0.0, 6.0),
-                          blurRadius: 10.0,
-                          spreadRadius: 0.0,
-                          color: _kKeyPenumbraOpacity,
-                        ),
-                        BoxShadow(
-                          offset: Offset(0.0, 1.0),
-                          blurRadius: 18.0,
-                          spreadRadius: 0.0,
-                          color: _kAmbientShadowOpacity,
-                        ),
-                      ],
+                  child: CupertinoUserInterfaceLevel(
+                    data: CupertinoUserInterfaceLevelData.elevated,
+                    child: Builder(
+                      builder: (BuildContext context) {
+                        return Container(
+                          padding: const EdgeInsets.symmetric(
+                            vertical: 64.0,
+                            horizontal: 16.0,
+                          ),
+                          decoration: BoxDecoration(
+                            color: CupertinoTheme.of(context).scaffoldBackgroundColor,
+                            borderRadius: BorderRadius.circular(3.0),
+                            boxShadow: const <BoxShadow>[
+                              BoxShadow(
+                                offset: Offset(0.0, 3.0),
+                                blurRadius: 5.0,
+                                spreadRadius: -1.0,
+                                color: _kKeyUmbraOpacity,
+                              ),
+                              BoxShadow(
+                                offset: Offset(0.0, 6.0),
+                                blurRadius: 10.0,
+                                spreadRadius: 0.0,
+                                color: _kKeyPenumbraOpacity,
+                              ),
+                              BoxShadow(
+                                offset: Offset(0.0, 1.0),
+                                blurRadius: 18.0,
+                                spreadRadius: 0.0,
+                                color: _kAmbientShadowOpacity,
+                              ),
+                            ],
+                          ),
+                          child: icons[currentSegment],
+                        );
+                      },
                     ),
-                    child: icons[sharedValue],
                   ),
                 ),
               ),

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

@@ -33,7 +33,7 @@ class CupertinoButton extends StatefulWidget {
     this.color,
     this.disabledColor = CupertinoColors.quaternarySystemFill,
     this.minSize = kMinInteractiveDimensionCupertino,
-    this.pressedOpacity = 0.1,
+    this.pressedOpacity = 0.4,
     this.borderRadius = const BorderRadius.all(Radius.circular(8.0)),
     @required this.onPressed,
   }) : assert(pressedOpacity == null || (pressedOpacity >= 0.0 && pressedOpacity <= 1.0)),
@@ -53,7 +53,7 @@ class CupertinoButton extends StatefulWidget {
     this.padding,
     this.disabledColor = CupertinoColors.quaternarySystemFill,
     this.minSize = kMinInteractiveDimensionCupertino,
-    this.pressedOpacity = 0.1,
+    this.pressedOpacity = 0.4,
     this.borderRadius = const BorderRadius.all(Radius.circular(8.0)),
     @required this.onPressed,
   }) : assert(pressedOpacity == null || (pressedOpacity >= 0.0 && pressedOpacity <= 1.0)),
@@ -102,7 +102,7 @@ class CupertinoButton extends StatefulWidget {
   /// The opacity that the button will fade to when it is pressed.
   /// The button will have an opacity of 1.0 when it is not pressed.
   ///
-  /// This defaults to 0.1. If null, opacity will not change on pressed if using
+  /// This defaults to 0.4. If null, opacity will not change on pressed if using
   /// your own custom effects is desired.
   final double pressedOpacity;
 

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

@@ -304,15 +304,15 @@ class CupertinoColors {
   /// The color for text labels containing secondary content, equivalent to
   /// [UIColor.secondaryLabel](https://developer.apple.com/documentation/uikit/uicolor/3173136-secondarylabel).
   static const CupertinoDynamicColor secondaryLabel = CupertinoDynamicColor(
-    color: Color.fromARGB(255, 0, 0, 0),
-    darkColor: Color.fromARGB(255, 255, 255, 255),
-    highContrastColor: Color.fromARGB(255, 0, 0, 0),
-    darkHighContrastColor: Color.fromARGB(255, 255, 255, 255),
-    elevatedColor: Color.fromARGB(255, 0, 0, 0),
-    darkElevatedColor: Color.fromARGB(255, 255, 255, 255),
-    highContrastElevatedColor: Color.fromARGB(255, 0, 0, 0),
-    darkHighContrastElevatedColor: Color.fromARGB(255, 255, 255, 255),
-  );
+    color: Color.fromARGB(153, 60, 60, 67),
+    darkColor: Color.fromARGB(153, 235, 235, 245),
+    highContrastColor: Color.fromARGB(173, 60, 60, 67),
+    darkHighContrastColor: Color.fromARGB(173, 235, 235, 245),
+    elevatedColor: Color.fromARGB(153, 60, 60, 67),
+    darkElevatedColor: Color.fromARGB(153, 235, 235, 245),
+    highContrastElevatedColor: Color.fromARGB(173, 60, 60, 67),
+    darkHighContrastElevatedColor: Color.fromARGB(173, 235, 235, 245),
+);
 
   /// The color for text labels containing tertiary content, equivalent to
   /// [UIColor.tertiaryLabel](https://developer.apple.com/documentation/uikit/uicolor/3173153-tertiarylabel).
@@ -889,7 +889,7 @@ class CupertinoDynamicColor extends Color {
   /// brightness, normal contrast, [CupertinoUserInterfaceLevelData.base] elevation
   /// level), unless [nullOk] is set to false, in which case an exception will be
   /// thrown.
-  CupertinoDynamicColor resolveFrom(BuildContext context, { bool nullOk = false }) {
+  CupertinoDynamicColor resolveFrom(BuildContext context, { bool nullOk = true }) {
     final Brightness brightness = _isPlatformBrightnessDependent
       ? CupertinoTheme.brightnessOf(context, nullOk: nullOk) ?? Brightness.light
       : Brightness.light;

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

@@ -13,6 +13,7 @@ import 'package:flutter/widgets.dart';
 import 'package:flutter/animation.dart' show Curves;
 
 import 'colors.dart';
+import 'interface_level.dart';
 
 const double _kBackGestureWidth = 20.0;
 const double _kMinFlingVelocity = 1.0; // Screen widths per second.
@@ -840,7 +841,10 @@ class _CupertinoModalPopupRoute<T> extends PopupRoute<T> {
 
   @override
   Widget buildPage(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
-    return builder(context);
+    return CupertinoUserInterfaceLevel(
+      data: CupertinoUserInterfaceLevelData.elevated,
+      child: Builder(builder: builder),
+    );
   }
 
   @override

packages/flutter/test/cupertino/button_test.dart

@@ -63,6 +63,44 @@ void main() {
     );
   });
 
+  // TODO(LongCatIsLoong): Uncomment once https://github.com/flutter/flutter/issues/44115
+  // is fixed.
+  /*
+  testWidgets(
+    'CupertinoButton.filled default color contrast meets guideline',
+    (WidgetTester tester) async {
+      // The native color combination systemBlue text over white background fails
+      // to pass the color contrast guideline.
+      //await tester.pumpWidget(
+      //  CupertinoTheme(
+      //    data: const CupertinoThemeData(),
+      //    child: Directionality(
+      //      textDirection: TextDirection.ltr,
+      //      child: CupertinoButton.filled(
+      //        child: const Text('Button'),
+      //        onPressed: () {},
+      //      ),
+      //    ),
+      //  ),
+      //);
+      //await expectLater(tester, meetsGuideline(textContrastGuideline));
+
+      await tester.pumpWidget(
+        CupertinoApp(
+          theme: const CupertinoThemeData(brightness: Brightness.dark),
+          home: CupertinoPageScaffold(
+            child: CupertinoButton.filled(
+              child: const Text('Button'),
+              onPressed: () {},
+            ),
+          ),
+        ),
+      );
+
+      await expectLater(tester, meetsGuideline(textContrastGuideline));
+  });
+  */
+
   testWidgets('Button with background is wider', (WidgetTester tester) async {
     await tester.pumpWidget(boilerplate(child: const CupertinoButton(
       child: Text('X', style: testStyle),
@@ -145,7 +183,7 @@ void main() {
       of: find.byType(CupertinoButton),
       matching: find.byType(FadeTransition),
     ));
-    expect(opacity.opacity.value, 0.1);
+    expect(opacity.opacity.value, 0.4);
   });
 
   testWidgets('pressedOpacity parameter', (WidgetTester tester) async {

packages/flutter/test/cupertino/dialog_test.dart

@@ -978,19 +978,19 @@ void main() {
 
     await tester.pump(const Duration(milliseconds: 25));
     transition = tester.firstWidget(find.byType(FadeTransition));
-    expect(transition.opacity.value, closeTo(0.10, 0.001));
+    expect(transition.opacity.value, closeTo(0.40, 0.001));
 
     await tester.pump(const Duration(milliseconds: 25));
     transition = tester.firstWidget(find.byType(FadeTransition));
-    expect(transition.opacity.value, closeTo(0.156, 0.001));
+    expect(transition.opacity.value, closeTo(0.437, 0.001));
 
     await tester.pump(const Duration(milliseconds: 25));
     transition = tester.firstWidget(find.byType(FadeTransition));
-    expect(transition.opacity.value, closeTo(0.324, 0.001));
+    expect(transition.opacity.value, closeTo(0.55, 0.001));
 
     await tester.pump(const Duration(milliseconds: 25));
     transition = tester.firstWidget(find.byType(FadeTransition));
-    expect(transition.opacity.value, closeTo(0.606, 0.001));
+    expect(transition.opacity.value, closeTo(0.737, 0.001));
 
     await tester.pump(const Duration(milliseconds: 25));
     transition = tester.firstWidget(find.byType(FadeTransition));