Adds CupertinoTheme (#23759)

bin/internal/goldens.version

-e07cc0cb4fdf912062e71a6fd97cc91478d6e3b9
+c47f1308188dca65b3899228cac37f252ea8b411

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

@@ -13,8 +13,11 @@ class CupertinoProgressIndicatorDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     return CupertinoPageScaffold(
       navigationBar: CupertinoNavigationBar(
-        previousPageTitle: 'Back',
-        middle: const Text('Cupertino Activity Indicator'),
+        // We're specifying a back label here because the previous page is a
+        // Material page. CupertinoPageRoutes could auto-populate these back
+        // labels.
+        previousPageTitle: 'Cupertino',
+        middle: const Text('Activity Indicator'),
         trailing: CupertinoDemoDocumentationButton(routeName),
       ),
       child: const Center(

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

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/cupertino.dart';
-import 'package:flutter/material.dart';
 
 import '../../gallery/demo.dart';
 
@@ -19,64 +18,71 @@ class _CupertinoButtonDemoState extends State<CupertinoButtonsDemo> {
 
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Cupertino Buttons'),
-        actions: <Widget>[MaterialDemoDocumentationButton(CupertinoButtonsDemo.routeName)],
+    return CupertinoPageScaffold(
+      navigationBar: CupertinoNavigationBar(
+        middle: const Text('Buttons'),
+        // 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(CupertinoButtonsDemo.routeName),
       ),
-      body: Column(
-        children: <Widget> [
-          const Padding(
-            padding: EdgeInsets.all(16.0),
-            child: Text(
-              'iOS themed buttons are flat. They can have borders or backgrounds but '
-              'only when necessary.'
-            ),
-          ),
-          Expanded(
-            child: Column(
-              mainAxisAlignment: MainAxisAlignment.center,
-              children: <Widget> [
-                Text(_pressedCount > 0
-                    ? 'Button pressed $_pressedCount time${_pressedCount == 1 ? "" : "s"}'
-                    : ' '),
-                const Padding(padding: EdgeInsets.all(12.0)),
-                Align(
-                  alignment: const Alignment(0.0, -0.2),
-                  child: Row(
-                    mainAxisSize: MainAxisSize.min,
-                    children: <Widget>[
-                      CupertinoButton(
-                        child: const Text('Cupertino Button'),
-                        onPressed: () {
-                          setState(() { _pressedCount += 1; });
-                        }
-                      ),
-                      const CupertinoButton(
-                        child: Text('Disabled'),
-                        onPressed: null,
-                      ),
-                    ],
-                  ),
+      child: DefaultTextStyle(
+        style: CupertinoTheme.of(context).textTheme.textStyle,
+        child: SafeArea(
+          child: Column(
+            children: <Widget>[
+              const Padding(
+                padding: EdgeInsets.all(16.0),
+                child: Text(
+                  'iOS themed buttons are flat. They can have borders or backgrounds but '
+                  'only when necessary.'
                 ),
-                const Padding(padding: EdgeInsets.all(12.0)),
-                CupertinoButton(
-                  child: const Text('With Background'),
-                  color: CupertinoColors.activeBlue,
-                  onPressed: () {
-                    setState(() { _pressedCount += 1; });
-                  }
-                ),
-                const Padding(padding: EdgeInsets.all(12.0)),
-                const CupertinoButton(
-                  child: Text('Disabled'),
-                  color: CupertinoColors.activeBlue,
-                  onPressed: null,
+              ),
+              Expanded(
+                child: Column(
+                  mainAxisAlignment: MainAxisAlignment.center,
+                  children: <Widget> [
+                    Text(_pressedCount > 0
+                        ? 'Button pressed $_pressedCount time${_pressedCount == 1 ? "" : "s"}'
+                        : ' '),
+                    const Padding(padding: EdgeInsets.all(12.0)),
+                    Align(
+                      alignment: const Alignment(0.0, -0.2),
+                      child: Row(
+                        mainAxisSize: MainAxisSize.min,
+                        children: <Widget>[
+                          CupertinoButton(
+                            child: const Text('Cupertino Button'),
+                            onPressed: () {
+                              setState(() { _pressedCount += 1; });
+                            }
+                          ),
+                          const CupertinoButton(
+                            child: Text('Disabled'),
+                            onPressed: null,
+                          ),
+                        ],
+                      ),
+                    ),
+                    const Padding(padding: EdgeInsets.all(12.0)),
+                    CupertinoButton.filled(
+                      child: const Text('With Background'),
+                      onPressed: () {
+                        setState(() { _pressedCount += 1; });
+                      }
+                    ),
+                    const Padding(padding: EdgeInsets.all(12.0)),
+                    const CupertinoButton.filled(
+                      child: Text('Disabled'),
+                      onPressed: null,
+                    ),
+                  ],
                 ),
-              ],
-            )
+              ),
+            ],
           ),
-        ],
+        ),
       )
     );
   }

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

@@ -52,11 +52,7 @@ class CupertinoNavigationDemo extends StatelessWidget {
       // Prevent swipe popping of this page. Use explicit exit buttons only.
       onWillPop: () => Future<bool>.value(true),
       child: DefaultTextStyle(
-        style: const TextStyle(
-          fontFamily: '.SF UI Text',
-          fontSize: 17.0,
-          color: CupertinoColors.black,
-        ),
+        style: CupertinoTheme.of(context).textTheme.textStyle,
         child: CupertinoTabScaffold(
           tabBar: CupertinoTabBar(
             items: const <BottomNavigationBarItem>[
@@ -241,7 +237,6 @@ class Tab1RowItem extends StatelessWidget {
               CupertinoButton(
                 padding: EdgeInsets.zero,
                 child: const Icon(CupertinoIcons.plus_circled,
-                  color: CupertinoColors.activeBlue,
                   semanticLabel: 'Add',
                 ),
                 onPressed: () { },
@@ -249,7 +244,6 @@ class Tab1RowItem extends StatelessWidget {
               CupertinoButton(
                 padding: EdgeInsets.zero,
                 child: const Icon(CupertinoIcons.share,
-                  color: CupertinoColors.activeBlue,
                   semanticLabel: 'Share',
                 ),
                 onPressed: () { },
@@ -352,8 +346,7 @@ class Tab1ItemPageState extends State<Tab1ItemPage> {
                         Row(
                           mainAxisAlignment: MainAxisAlignment.spaceBetween,
                           children: <Widget>[
-                            CupertinoButton(
-                              color: CupertinoColors.activeBlue,
+                            CupertinoButton.filled(
                               minSize: 30.0,
                               padding: const EdgeInsets.symmetric(horizontal: 24.0),
                               borderRadius: BorderRadius.circular(32.0),
@@ -367,12 +360,11 @@ class Tab1ItemPageState extends State<Tab1ItemPage> {
                               ),
                               onPressed: () { },
                             ),
-                            CupertinoButton(
-                              color: CupertinoColors.activeBlue,
+                            CupertinoButton.filled(
                               minSize: 30.0,
                               padding: EdgeInsets.zero,
                               borderRadius: BorderRadius.circular(32.0),
-                              child: const Icon(CupertinoIcons.ellipsis, color: CupertinoColors.white),
+                              child: const Icon(CupertinoIcons.ellipsis),
                               onPressed: () { },
                             ),
                           ],
@@ -722,7 +714,11 @@ class CupertinoDemoTab3 extends StatelessWidget {
         trailing: trailingButtons,
       ),
       child: DecoratedBox(
-        decoration: const BoxDecoration(color: Color(0xFFEFEFF4)),
+        decoration: BoxDecoration(
+          color: CupertinoTheme.of(context).brightness == Brightness.light
+              ? CupertinoColors.extraLightBackgroundGray
+              : CupertinoColors.darkBackgroundGray,
+        ),
         child: ListView(
           children: <Widget>[
             const Padding(padding: EdgeInsets.only(top: 32.0)),
@@ -736,9 +732,9 @@ class CupertinoDemoTab3 extends StatelessWidget {
                 );
               },
               child: Container(
-                decoration: const BoxDecoration(
-                  color: CupertinoColors.white,
-                  border: Border(
+                decoration: BoxDecoration(
+                  color: CupertinoTheme.of(context).scaffoldBackgroundColor,
+                  border: const Border(
                     top: BorderSide(color: Color(0xFFBCBBC1), width: 0.0),
                     bottom: BorderSide(color: Color(0xFFBCBBC1), width: 0.0),
                   ),
@@ -750,10 +746,10 @@ class CupertinoDemoTab3 extends StatelessWidget {
                     top: false,
                     bottom: false,
                     child: Row(
-                      children: const <Widget>[
+                      children: <Widget>[
                         Text(
                           'Sign in',
-                          style: TextStyle(color: CupertinoColors.activeBlue),
+                          style: TextStyle(color: CupertinoTheme.of(context).primaryColor),
                         )
                       ],
                     ),
@@ -791,8 +787,7 @@ class Tab3Dialog extends StatelessWidget {
               color: Color(0xFF646464),
             ),
             const Padding(padding: EdgeInsets.only(top: 18.0)),
-            CupertinoButton(
-              color: CupertinoColors.activeBlue,
+            CupertinoButton.filled(
               child: const Text('Sign in'),
               onPressed: () {
                 Navigator.pop(context);

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

@@ -2,7 +2,6 @@
 // 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/material.dart';
 import 'package:intl/intl.dart';
 
 import '../../gallery/demo.dart';
@@ -34,9 +33,9 @@ class _CupertinoPickerDemoState extends State<CupertinoPickerDemo> {
 
   Widget _buildMenu(List<Widget> children) {
     return Container(
-      decoration: const BoxDecoration(
-        color: CupertinoColors.white,
-        border: Border(
+      decoration: BoxDecoration(
+        color: CupertinoTheme.of(context).scaffoldBackgroundColor,
+        border: const Border(
           top: BorderSide(color: Color(0xFFBCBBC1), width: 0.0),
           bottom: BorderSide(color: Color(0xFFBCBBC1), width: 0.0),
         ),
@@ -47,16 +46,9 @@ class _CupertinoPickerDemoState extends State<CupertinoPickerDemo> {
         child: SafeArea(
           top: false,
           bottom: false,
-          child: DefaultTextStyle(
-            style: const TextStyle(
-              letterSpacing: -0.24,
-              fontSize: 17.0,
-              color: CupertinoColors.black,
-            ),
-            child: Row(
-              mainAxisAlignment: MainAxisAlignment.spaceBetween,
-              children: children,
-            ),
+          child: Row(
+            mainAxisAlignment: MainAxisAlignment.spaceBetween,
+            children: children,
           ),
         ),
       ),
@@ -249,19 +241,23 @@ class _CupertinoPickerDemoState extends State<CupertinoPickerDemo> {
 
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Cupertino Picker'),
-        actions: <Widget>[MaterialDemoDocumentationButton(CupertinoPickerDemo.routeName)],
+    return CupertinoPageScaffold(
+      navigationBar: CupertinoNavigationBar(
+        middle: const Text('Picker'),
+        // 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(CupertinoPickerDemo.routeName),
       ),
-      body: DefaultTextStyle(
-        style: const TextStyle(
-          fontFamily: '.SF UI Text',
-          fontSize: 17.0,
-          color: CupertinoColors.black,
-        ),
+      child: DefaultTextStyle(
+        style: CupertinoTheme.of(context).textTheme.textStyle,
         child: DecoratedBox(
-          decoration: const BoxDecoration(color: Color(0xFFEFEFF4)),
+          decoration: BoxDecoration(
+            color: CupertinoTheme.of(context).brightness == Brightness.light
+                ? CupertinoColors.extraLightBackgroundGray
+                : CupertinoColors.darkBackgroundGray,
+          ),
           child: ListView(
             children: <Widget>[
               const Padding(padding: EdgeInsets.only(top: 32.0)),

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

@@ -39,19 +39,21 @@ class _CupertinoRefreshControlDemoState extends State<CupertinoRefreshControlDem
   @override
   Widget build(BuildContext context) {
     return DefaultTextStyle(
-      style: const TextStyle(
-        fontFamily: '.SF UI Text',
-        inherit: false,
-        fontSize: 17.0,
-        color: CupertinoColors.black,
-      ),
+      style: CupertinoTheme.of(context).textTheme.textStyle,
       child: CupertinoPageScaffold(
         child: DecoratedBox(
-          decoration: const BoxDecoration(color: Color(0xFFEFEFF4)),
+          decoration: BoxDecoration(
+            color: CupertinoTheme.of(context).brightness == Brightness.light
+                ? CupertinoColors.extraLightBackgroundGray
+                : CupertinoColors.darkBackgroundGray,
+          ),
           child: CustomScrollView(
             slivers: <Widget>[
               CupertinoSliverNavigationBar(
-                largeTitle: const Text('Cupertino Refresh'),
+                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),
               ),
@@ -152,7 +154,7 @@ class _ListItem extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Container(
-      color: CupertinoColors.white,
+      color: CupertinoTheme.of(context).scaffoldBackgroundColor,
       height: 60.0,
       padding: const EdgeInsets.only(top: 9.0),
       child: Row(
@@ -215,11 +217,11 @@ class _ListItem extends StatelessWidget {
                       letterSpacing: -0.41,
                     ),
                   ),
-                  const Padding(
-                    padding: EdgeInsets.only(left: 9.0),
+                  Padding(
+                    padding: const EdgeInsets.only(left: 9.0),
                     child: Icon(
                       CupertinoIcons.info,
-                      color: CupertinoColors.activeBlue
+                      color: CupertinoTheme.of(context).primaryColor,
                     ),
                   ),
                 ],

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

@@ -50,68 +50,77 @@ class _CupertinoSegmentedControlDemoState extends State<CupertinoSegmentedContro
 
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Segmented Control'),
-        actions: <Widget>[MaterialDemoDocumentationButton(CupertinoSegmentedControlDemo.routeName)],
+    return CupertinoPageScaffold(
+      navigationBar: CupertinoNavigationBar(
+        middle: const Text('Segmented Control'),
+        // 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(CupertinoSegmentedControlDemo.routeName),
       ),
-      body: Column(
-        children: <Widget>[
-          const Padding(
-            padding: EdgeInsets.all(16.0),
-          ),
-          SizedBox(
-            width: 500.0,
-            child: CupertinoSegmentedControl<int>(
-              children: children,
-              onValueChanged: (int newValue) {
-                setState(() {
-                  sharedValue = newValue;
-                });
-              },
-              groupValue: sharedValue,
-            ),
-          ),
-          Expanded(
-            child: Padding(
-              padding: const EdgeInsets.symmetric(
-                vertical: 32.0,
-                horizontal: 16.0,
+      child: DefaultTextStyle(
+        style: CupertinoTheme.of(context).textTheme.textStyle,
+        child: SafeArea(
+          child: Column(
+            children: <Widget>[
+              const Padding(
+                padding: EdgeInsets.all(16.0),
               ),
-              child: Container(
-                padding: const EdgeInsets.symmetric(
-                  vertical: 64.0,
-                  horizontal: 16.0,
+              SizedBox(
+                width: 500.0,
+                child: CupertinoSegmentedControl<int>(
+                  children: children,
+                  onValueChanged: (int newValue) {
+                    setState(() {
+                      sharedValue = newValue;
+                    });
+                  },
+                  groupValue: sharedValue,
                 ),
-                decoration: BoxDecoration(
-                  color: CupertinoColors.white,
-                  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,
+              ),
+              Expanded(
+                child: Padding(
+                  padding: const EdgeInsets.symmetric(
+                    vertical: 32.0,
+                    horizontal: 16.0,
+                  ),
+                  child: Container(
+                    padding: const EdgeInsets.symmetric(
+                      vertical: 64.0,
+                      horizontal: 16.0,
                     ),
-                    BoxShadow(
-                      offset: Offset(0.0, 1.0),
-                      blurRadius: 18.0,
-                      spreadRadius: 0.0,
-                      color: _kAmbientShadowOpacity,
+                    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[sharedValue],
+                  ),
                 ),
-                child: icons[sharedValue],
               ),
-            ),
+            ],
           ),
-        ],
+        ),
       ),
     );
   }

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

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/cupertino.dart';
-import 'package:flutter/material.dart';
 
 import '../../gallery/demo.dart';
 
@@ -20,49 +19,58 @@ class _CupertinoSliderDemoState extends State<CupertinoSliderDemo> {
 
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Cupertino Sliders'),
-        actions: <Widget>[MaterialDemoDocumentationButton(CupertinoSliderDemo.routeName)],
+    return CupertinoPageScaffold(
+      navigationBar: CupertinoNavigationBar(
+        middle: const Text('Sliders'),
+        // 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(CupertinoSliderDemo.routeName),
       ),
-      body: Center(
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.spaceAround,
-          children: <Widget>[
-            Column(
-              mainAxisSize: MainAxisSize.min,
-              children: <Widget> [
-                CupertinoSlider(
-                  value: _value,
-                  min: 0.0,
-                  max: 100.0,
-                  onChanged: (double value) {
-                    setState(() {
-                      _value = value;
-                    });
-                  }
+      child: DefaultTextStyle(
+        style: CupertinoTheme.of(context).textTheme.textStyle,
+        child: SafeArea(
+          child: Center(
+            child: Column(
+              mainAxisAlignment: MainAxisAlignment.spaceAround,
+              children: <Widget>[
+                Column(
+                  mainAxisSize: MainAxisSize.min,
+                  children: <Widget> [
+                    CupertinoSlider(
+                      value: _value,
+                      min: 0.0,
+                      max: 100.0,
+                      onChanged: (double value) {
+                        setState(() {
+                          _value = value;
+                        });
+                      }
+                    ),
+                    Text('Cupertino Continuous: ${_value.toStringAsFixed(1)}'),
+                  ]
                 ),
-                Text('Cupertino Continuous: ${_value.toStringAsFixed(1)}'),
-              ]
-            ),
-            Column(
-              mainAxisSize: MainAxisSize.min,
-              children: <Widget> [
-                CupertinoSlider(
-                  value: _discreteValue,
-                  min: 0.0,
-                  max: 100.0,
-                  divisions: 5,
-                  onChanged: (double value) {
-                    setState(() {
-                      _discreteValue = value;
-                    });
-                  }
+                Column(
+                  mainAxisSize: MainAxisSize.min,
+                  children: <Widget> [
+                    CupertinoSlider(
+                      value: _discreteValue,
+                      min: 0.0,
+                      max: 100.0,
+                      divisions: 5,
+                      onChanged: (double value) {
+                        setState(() {
+                          _discreteValue = value;
+                        });
+                      }
+                    ),
+                    Text('Cupertino Discrete: $_discreteValue'),
+                  ]
                 ),
-                Text('Cupertino Discrete: $_discreteValue'),
-              ]
+              ],
             ),
-          ],
+          ),
         ),
       ),
     );

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

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/cupertino.dart';
-import 'package:flutter/material.dart';
 
 import '../../gallery/demo.dart';
 
@@ -20,62 +19,71 @@ class _CupertinoSwitchDemoState extends State<CupertinoSwitchDemo> {
 
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Cupertino Switch'),
-        actions: <Widget>[MaterialDemoDocumentationButton(CupertinoSwitchDemo.routeName)],
+    return CupertinoPageScaffold(
+      navigationBar: CupertinoNavigationBar(
+        middle: const Text('Switch'),
+        // 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(CupertinoSwitchDemo.routeName),
       ),
-      body: Center(
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.spaceAround,
-          children: <Widget>[
-            Semantics(
-              container: true,
-              child: Column(
-                children: <Widget>[
-                  CupertinoSwitch(
-                    value: _switchValue,
-                    onChanged: (bool value) {
-                      setState(() {
-                        _switchValue = value;
-                      });
-                    },
+      child: DefaultTextStyle(
+        style: CupertinoTheme.of(context).textTheme.textStyle,
+        child: SafeArea(
+          child: Center(
+            child: Column(
+              mainAxisAlignment: MainAxisAlignment.spaceAround,
+              children: <Widget>[
+                Semantics(
+                  container: true,
+                  child: Column(
+                    children: <Widget>[
+                      CupertinoSwitch(
+                        value: _switchValue,
+                        onChanged: (bool value) {
+                          setState(() {
+                            _switchValue = value;
+                          });
+                        },
+                      ),
+                      const Text(
+                        'Active'
+                      ),
+                    ],
                   ),
-                  const Text(
-                    'Active'
+                ),
+                Semantics(
+                  container: true,
+                  child: Column(
+                    children: const <Widget>[
+                      CupertinoSwitch(
+                        value: true,
+                        onChanged: null,
+                      ),
+                      Text(
+                        'Disabled'
+                      ),
+                    ],
                   ),
-                ],
-              ),
-            ),
-            Semantics(
-              container: true,
-              child: Column(
-                children: const <Widget>[
-                  CupertinoSwitch(
-                    value: true,
-                    onChanged: null,
-                  ),
-                  Text(
-                    'Disabled'
-                  ),
-                ],
-              ),
-            ),
-            Semantics(
-              container: true,
-              child: Column(
-                children: const <Widget>[
-                  CupertinoSwitch(
-                    value: false,
-                    onChanged: null,
-                  ),
-                  Text(
-                    'Disabled'
+                ),
+                Semantics(
+                  container: true,
+                  child: Column(
+                    children: const <Widget>[
+                      CupertinoSwitch(
+                        value: false,
+                        onChanged: null,
+                      ),
+                      Text(
+                        'Disabled'
+                      ),
+                    ],
                   ),
-                ],
-              ),
+                ),
+              ],
             ),
-          ],
+          ),
         ),
       ),
     );

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

@@ -160,6 +160,9 @@ class _CupertinoTextFieldDemoState extends State<CupertinoTextFieldDemo> {
       ),
       child: CupertinoPageScaffold(
         navigationBar: const CupertinoNavigationBar(
+          // We're specifying a back label here because the previous page is a
+          // Material page. CupertinoPageRoutes could auto-populate these back
+          // labels.
           previousPageTitle: 'Cupertino',
           middle: Text('Text Fields'),
         ),

examples/flutter_gallery/lib/gallery/app.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart' show defaultTargetPlatform;
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart' show timeDilation;
@@ -125,7 +126,6 @@ class _GalleryAppState extends State<GalleryApp> {
         child: home,
       );
     }
-
     return MaterialApp(
       theme: _options.theme.data.copyWith(platform: _options.platform),
       title: 'Flutter Gallery',
@@ -137,7 +137,17 @@ class _GalleryAppState extends State<GalleryApp> {
       builder: (BuildContext context, Widget child) {
         return Directionality(
           textDirection: _options.textDirection,
-          child: _applyTextScaleFactor(child),
+          child: _applyTextScaleFactor(
+            // Specifically use a blank Cupertino theme here and do not transfer
+            // over the Material primary color etc except the brightness to
+            // showcase standard iOS looks.
+            CupertinoTheme(
+              data: CupertinoThemeData(
+                brightness: _options.theme.data.brightness,
+              ),
+              child: child,
+            ),
+          ),
         );
       },
       home: home,

packages/flutter/lib/cupertino.dart

@@ -30,5 +30,7 @@ export 'src/cupertino/tab_scaffold.dart';
 export 'src/cupertino/tab_view.dart';
 export 'src/cupertino/text_field.dart';
 export 'src/cupertino/text_selection.dart';
+export 'src/cupertino/text_theme.dart';
+export 'src/cupertino/theme.dart';
 export 'src/cupertino/thumb_painter.dart';
 export 'widgets.dart';

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

@@ -10,16 +10,7 @@ import 'colors.dart';
 import 'icons.dart';
 import 'localizations.dart';
 import 'route.dart';
-
-// Based on specs from https://developer.apple.com/design/resources/ for
-// iOS 12.
-const TextStyle _kDefaultTextStyle = TextStyle(
-  fontFamily: '.SF Pro Text',
-  fontSize: 17.0,
-  letterSpacing: -0.38,
-  color: CupertinoColors.black,
-  decoration: TextDecoration.none,
-);
+import 'theme.dart';
 
 /// An application that uses Cupertino design.
 ///
@@ -79,6 +70,7 @@ class CupertinoApp extends StatefulWidget {
     Key key,
     this.navigatorKey,
     this.home,
+    this.theme,
     this.routes = const <String, WidgetBuilder>{},
     this.initialRoute,
     this.onGenerateRoute,
@@ -114,6 +106,12 @@ class CupertinoApp extends StatefulWidget {
   /// {@macro flutter.widgets.widgetsApp.home}
   final Widget home;
 
+  /// The top-level [CupertinoTheme] styling.
+  ///
+  /// A null [theme] or unspecified [theme] attributes will default to iOS
+  /// system values.
+  final CupertinoThemeData theme;
+
   /// The application's top-level routing table.
   ///
   /// When a named route is pushed with [Navigator.pushNamed], the route name is
@@ -266,48 +264,52 @@ class _CupertinoAppState extends State<CupertinoApp> {
 
   @override
   Widget build(BuildContext context) {
+    final CupertinoThemeData effectiveThemeData = widget.theme ?? const CupertinoThemeData();
+
     return ScrollConfiguration(
       behavior: _AlwaysCupertinoScrollBehavior(),
-      child: WidgetsApp(
-        key: GlobalObjectKey(this),
-        navigatorKey: widget.navigatorKey,
-        navigatorObservers: _navigatorObservers,
-        // TODO(dnfield): when https://github.com/dart-lang/sdk/issues/34572 is resolved
-        // this can use type arguments again
-        pageRouteBuilder: (RouteSettings settings, WidgetBuilder builder) =>
-          CupertinoPageRoute<dynamic>(settings: settings, builder: builder),
-        home: widget.home,
-        routes: widget.routes,
-        initialRoute: widget.initialRoute,
-        onGenerateRoute: widget.onGenerateRoute,
-        onUnknownRoute: widget.onUnknownRoute,
-        builder: widget.builder,
-        title: widget.title,
-        onGenerateTitle: widget.onGenerateTitle,
-        textStyle: _kDefaultTextStyle,
-        color: widget.color ?? CupertinoColors.activeBlue,
-        locale: widget.locale,
-        localizationsDelegates: _localizationsDelegates,
-        localeResolutionCallback: widget.localeResolutionCallback,
-        localeListResolutionCallback: widget.localeListResolutionCallback,
-        supportedLocales: widget.supportedLocales,
-        showPerformanceOverlay: widget.showPerformanceOverlay,
-        checkerboardRasterCacheImages: widget.checkerboardRasterCacheImages,
-        checkerboardOffscreenLayers: widget.checkerboardOffscreenLayers,
-        showSemanticsDebugger: widget.showSemanticsDebugger,
-        debugShowCheckedModeBanner: widget.debugShowCheckedModeBanner,
-        inspectorSelectButtonBuilder: (BuildContext context, VoidCallback onPressed) {
-          return CupertinoButton(
-            child: const Icon(
-              CupertinoIcons.search,
-              size: 28.0,
-              color: CupertinoColors.white,
-            ),
-            color: CupertinoColors.activeBlue,
-            padding: EdgeInsets.zero,
-            onPressed: onPressed,
-          );
-        },
+      child: CupertinoTheme(
+        data: effectiveThemeData,
+        child: WidgetsApp(
+          key: GlobalObjectKey(this),
+          navigatorKey: widget.navigatorKey,
+          navigatorObservers: _navigatorObservers,
+          // TODO(dnfield): when https://github.com/dart-lang/sdk/issues/34572 is resolved
+          // this can use type arguments again
+          pageRouteBuilder: (RouteSettings settings, WidgetBuilder builder) =>
+            CupertinoPageRoute<dynamic>(settings: settings, builder: builder),
+          home: widget.home,
+          routes: widget.routes,
+          initialRoute: widget.initialRoute,
+          onGenerateRoute: widget.onGenerateRoute,
+          onUnknownRoute: widget.onUnknownRoute,
+          builder: widget.builder,
+          title: widget.title,
+          onGenerateTitle: widget.onGenerateTitle,
+          textStyle: effectiveThemeData.textTheme.textStyle,
+          color: widget.color ?? CupertinoColors.activeBlue,
+          locale: widget.locale,
+          localizationsDelegates: _localizationsDelegates,
+          localeResolutionCallback: widget.localeResolutionCallback,
+          localeListResolutionCallback: widget.localeListResolutionCallback,
+          supportedLocales: widget.supportedLocales,
+          showPerformanceOverlay: widget.showPerformanceOverlay,
+          checkerboardRasterCacheImages: widget.checkerboardRasterCacheImages,
+          checkerboardOffscreenLayers: widget.checkerboardOffscreenLayers,
+          showSemanticsDebugger: widget.showSemanticsDebugger,
+          debugShowCheckedModeBanner: widget.debugShowCheckedModeBanner,
+          inspectorSelectButtonBuilder: (BuildContext context, VoidCallback onPressed) {
+            return CupertinoButton.filled(
+              child: const Icon(
+                CupertinoIcons.search,
+                size: 28.0,
+                color: CupertinoColors.white,
+              ),
+              padding: EdgeInsets.zero,
+              onPressed: onPressed,
+            );
+          },
+        ),
       ),
     );
   }

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

@@ -7,11 +7,11 @@ import 'dart:ui' show ImageFilter;
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';
+import 'theme.dart';
 
 // Standard iOS 10 tab bar height.
 const double _kTabBarHeight = 50.0;
 
-const Color _kDefaultTabBarBackgroundColor = Color(0xCCF8F8F8);
 const Color _kDefaultTabBarBorderColor = Color(0x4C000000);
 
 /// An iOS-styled bottom navigation tab bar.
@@ -21,10 +21,12 @@ const Color _kDefaultTabBarBorderColor = Color(0x4C000000);
 ///
 /// This [StatelessWidget] doesn't store the active tab itself. You must
 /// listen to the [onTap] callbacks and call `setState` with a new [currentIndex]
-/// for the new selection to reflect.
+/// for the new selection to reflect. This can also be done automatically
+/// by wrapping this with a [CupertinoTabScaffold].
 ///
 /// Tab changes typically trigger a switch between [Navigator]s, each with its
-/// own navigation stack, per standard iOS design.
+/// own navigation stack, per standard iOS design. This can be done by using
+/// [CupertinoTabView]s inside each tab builder in [CupertinoTabScaffold].
 ///
 /// If the given [backgroundColor]'s opacity is not 1.0 (which is the case by
 /// default), it will produce a blurring effect to the content behind it.
@@ -40,8 +42,8 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
     @required this.items,
     this.onTap,
     this.currentIndex = 0,
-    this.backgroundColor = _kDefaultTabBarBackgroundColor,
-    this.activeColor = CupertinoColors.activeBlue,
+    this.backgroundColor,
+    this.activeColor,
     this.inactiveColor = CupertinoColors.inactiveGray,
     this.iconSize = 30.0,
     this.border = const Border(
@@ -56,6 +58,7 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
        assert(currentIndex != null),
        assert(0 <= currentIndex && currentIndex < items.length),
        assert(iconSize != null),
+       assert(inactiveColor != null),
        super(key: key);
 
   /// The interactive items laid out within the bottom navigation bar.
@@ -78,14 +81,20 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
   /// The background color of the tab bar. If it contains transparency, the
   /// tab bar will automatically produce a blurring effect to the content
   /// behind it.
+  ///
+  /// Defaults to [CupertinoTheme]'s `barBackgroundColor` when null.
   final Color backgroundColor;
 
   /// The foreground color of the icon and title for the [BottomNavigationBarItem]
   /// of the selected tab.
+  ///
+  /// Defaults to [CupertinoTheme]'s `primaryColor` if null.
   final Color activeColor;
 
   /// The foreground color of the icon and title for the [BottomNavigationBarItem]s
   /// in the unselected state.
+  ///
+  /// Defaults to [CupertinoColors.inactiveGray] and cannot be null.
   final Color inactiveColor;
 
   /// The size of all of the [BottomNavigationBarItem] icons.
@@ -102,19 +111,25 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
   /// The default value is a one physical pixel top border with grey color.
   final Border border;
 
-  /// True if the tab bar's background color has no transparency.
-  bool get opaque => backgroundColor.alpha == 0xFF;
-
   @override
   Size get preferredSize => const Size.fromHeight(_kTabBarHeight);
 
+  /// Indicates whether the tab bar is fully opaque or can have contents behind
+  /// it show through it.
+  bool opaque(BuildContext context) {
+    final Color backgroundColor =
+        this.backgroundColor ?? CupertinoTheme.of(context).barBackgroundColor;
+    return backgroundColor.alpha == 0xFF;
+  }
+
   @override
   Widget build(BuildContext context) {
     final double bottomPadding = MediaQuery.of(context).padding.bottom;
+
     Widget result = DecoratedBox(
       decoration: BoxDecoration(
         border: border,
-        color: backgroundColor,
+        color: backgroundColor ?? CupertinoTheme.of(context).barBackgroundColor,
       ),
       child: SizedBox(
         height: _kTabBarHeight + bottomPadding,
@@ -124,19 +139,13 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
             size: iconSize,
           ),
           child: DefaultTextStyle( // Default with the inactive state.
-            style: TextStyle(
-              fontFamily: '.SF UI Text',
-              fontSize: 10.0,
-              letterSpacing: 0.1,
-              fontWeight: FontWeight.w400,
-              color: inactiveColor,
-            ),
+            style: CupertinoTheme.of(context).textTheme.tabLabelTextStyle.copyWith(color: inactiveColor),
             child: Padding(
               padding: EdgeInsets.only(bottom: bottomPadding),
               child: Row(
                 // Align bottom since we want the labels to be aligned.
                 crossAxisAlignment: CrossAxisAlignment.end,
-                children: _buildTabItems(),
+                children: _buildTabItems(context),
               ),
             ),
           ),
@@ -144,7 +153,7 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
       ),
     );
 
-    if (!opaque) {
+    if (!opaque(context)) {
       // For non-opaque backgrounds, apply a blur effect.
       result = ClipRect(
         child: BackdropFilter(
@@ -157,13 +166,14 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
     return result;
   }
 
-  List<Widget> _buildTabItems() {
+  List<Widget> _buildTabItems(BuildContext context) {
     final List<Widget> result = <Widget>[];
 
     for (int index = 0; index < items.length; index += 1) {
       final bool active = index == currentIndex;
       result.add(
         _wrapActiveItem(
+          context,
           Expanded(
             child: Semantics(
               selected: active,
@@ -205,10 +215,11 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
   }
 
   /// Change the active tab item's icon and title colors to active.
-  Widget _wrapActiveItem(Widget item, { @required bool active }) {
+  Widget _wrapActiveItem(BuildContext context, Widget item, { @required bool active }) {
     if (!active)
       return item;
 
+    final Color activeColor = this.activeColor ?? CupertinoTheme.of(context).primaryColor;
     return IconTheme.merge(
       data: IconThemeData(color: activeColor),
       child: DefaultTextStyle.merge(

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

@@ -5,28 +5,11 @@
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
-import 'colors.dart';
+import 'theme.dart';
 
 const Color _kDisabledBackground = Color(0xFFA9A9A9);
-const Color _kDisabledForeground = Color(0xFFC4C4C4);
-
-const TextStyle _kButtonTextStyle = TextStyle(
-  fontFamily: '.SF UI Text',
-  inherit: false,
-  fontSize: 17.5,
-  letterSpacing: -0.24,
-  fontWeight: FontWeight.w400,
-  color: CupertinoColors.activeBlue,
-  textBaseline: TextBaseline.alphabetic,
-);
-
-final TextStyle _kDisabledButtonTextStyle = _kButtonTextStyle.copyWith(
-  color: _kDisabledForeground,
-);
-
-final TextStyle _kBackgroundButtonTextStyle = _kButtonTextStyle.copyWith(
-  color: CupertinoColors.white,
-);
+// Measured against iOS 12 in Xcode.
+const Color _kDisabledForeground = Color(0xFFD1D1D1);
 
 const EdgeInsets _kButtonPadding = EdgeInsets.all(16.0);
 const EdgeInsets _kBackgroundButtonPadding = EdgeInsets.symmetric(
@@ -53,7 +36,26 @@ class CupertinoButton extends StatefulWidget {
     this.pressedOpacity = 0.1,
     this.borderRadius = const BorderRadius.all(Radius.circular(8.0)),
     @required this.onPressed,
-  }) : assert(pressedOpacity == null || (pressedOpacity >= 0.0 && pressedOpacity <= 1.0));
+  }) : assert(pressedOpacity == null || (pressedOpacity >= 0.0 && pressedOpacity <= 1.0)),
+       _filled = false;
+
+  /// Creates an iOS-style button with a filled background.
+  ///
+  /// The background color is derived from the [CupertinoTheme]'s `primaryColor`.
+  ///
+  /// To specify a custom background color, use the [color] argument of the
+  /// default constructor.
+  const CupertinoButton.filled({
+    @required this.child,
+    this.padding,
+    this.disabledColor,
+    this.minSize = 44.0,
+    this.pressedOpacity = 0.1,
+    this.borderRadius = const BorderRadius.all(Radius.circular(8.0)),
+    @required this.onPressed,
+  }) : assert(pressedOpacity == null || (pressedOpacity >= 0.0 && pressedOpacity <= 1.0)),
+       color = null,
+       _filled = true;
 
   /// The widget below this widget in the tree.
   ///
@@ -68,6 +70,9 @@ class CupertinoButton extends StatefulWidget {
   /// The color of the button's background.
   ///
   /// Defaults to null which produces a button with no background or border.
+  ///
+  /// Defaults to the [CupertinoTheme]'s `primaryColor` when the
+  /// [CupertinoButton.filled] constructor is used.
   final Color color;
 
   /// The color of the button's background when the button is disabled.
@@ -105,6 +110,8 @@ class CupertinoButton extends StatefulWidget {
   /// Defaults to round corners of 8 logical pixels.
   final BorderRadius borderRadius;
 
+  final bool _filled;
+
   /// Whether the button is enabled or disabled. Buttons are disabled by default. To
   /// enable a button, set its [onPressed] property to a non-null value.
   bool get enabled => onPressed != null;
@@ -198,7 +205,15 @@ class _CupertinoButtonState extends State<CupertinoButton> with SingleTickerProv
   @override
   Widget build(BuildContext context) {
     final bool enabled = widget.enabled;
-    final Color backgroundColor = widget.color;
+    final Color primaryColor = CupertinoTheme.of(context).primaryColor;
+    final Color backgroundColor = widget.color ?? (widget._filled ? primaryColor : null);
+    final Color foregroundColor = backgroundColor != null
+        ? CupertinoTheme.of(context).primaryContrastingColor
+        : enabled
+            ? primaryColor
+            : _kDisabledForeground;
+    final TextStyle textStyle =
+        CupertinoTheme.of(context).textTheme.textStyle.copyWith(color: foregroundColor);
 
     return GestureDetector(
       behavior: HitTestBehavior.opaque,
@@ -232,12 +247,11 @@ class _CupertinoButtonState extends State<CupertinoButton> with SingleTickerProv
                   widthFactor: 1.0,
                   heightFactor: 1.0,
                   child: DefaultTextStyle(
-                    style: backgroundColor != null
-                      ? _kBackgroundButtonTextStyle
-                      : enabled
-                        ? _kButtonTextStyle
-                        : _kDisabledButtonTextStyle,
-                    child: widget.child,
+                    style: textStyle,
+                    child: IconTheme(
+                      data: IconThemeData(color: foregroundColor),
+                      child: widget.child,
+                    ),
                   ),
                 ),
               ),

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

@@ -11,15 +11,27 @@ class CupertinoColors {
 
   /// iOS 10's default blue color. Used to indicate active elements such as
   /// buttons, selected tabs and your own chat bubbles.
+  ///
+  /// This is SystemBlue in the iOS palette.
   static const Color activeBlue = Color(0xFF007AFF);
 
   /// iOS 10's default green color. Used to indicate active accents such as
   /// the switch in its on state and some accent buttons such as the call button
   /// and Apple Map's 'Go' button.
+  ///
+  /// This is SystemGreen in the iOS palette.
   static const Color activeGreen = Color(0xFF4CD964);
 
+  /// iOS 12's default dark mode color. Used in place of the [activeBlue] color
+  /// as the default active elements' color when the theme's brightness is dark.
+  ///
+  /// This is SystemOrange in the iOS palette.
+  static const Color activeOrange = Color(0xFFFF9500);
+
   /// Opaque white color. Used for backgrounds and fonts against dark backgrounds.
   ///
+  /// This is SystemWhiteColor in the iOS palette.
+  ///
   /// See also:
   ///
   ///  * [material.Colors.white], the same color, in the material design palette.
@@ -28,6 +40,8 @@ class CupertinoColors {
 
   /// Opaque black color. Used for texts against light backgrounds.
   ///
+  /// This is SystemBlackColor in the iOS palette.
+  ///
   /// See also:
   ///
   ///  * [material.Colors.black], the same color, in the material design palette.
@@ -35,12 +49,26 @@ class CupertinoColors {
   static const Color black = Color(0xFF000000);
 
   /// Used in iOS 10 for light background fills such as the chat bubble background.
+  ///
+  /// This is SystemLightGrayColor in the iOS palette.
   static const Color lightBackgroundGray = Color(0xFFE5E5EA);
 
+  /// Used in iOS 12 for very light background fills in tables between cell groups.
+  ///
+  /// This is SystemExtraLightGrayColor in the iOS palette.
+  static const Color extraLightBackgroundGray = Color(0xFFEFEFF4);
+
+  /// Used in iOS 12 for very dark background fills in tables between cell groups
+  /// in dark mode.
+  // Value derived from screenshot from the dark themed Apple Watch app.
+  static const Color darkBackgroundGray = Color(0xFF171717);
+
   /// Used in iOS 11 for unselected selectables such as tab bar items in their
   /// inactive state or de-emphasized subtitles and details text.
   ///
   /// Not the same gray as disabled buttons etc.
+  ///
+  /// This is SystemGrayColor in the iOS palette.
   static const Color inactiveGray = Color(0xFF8E8E93);
 
   /// Used for iOS 10 for destructive actions such as the delete actions in
@@ -48,5 +76,7 @@ class CupertinoColors {
   ///
   /// Not the same red as the camera shutter or springboard icon notifications
   /// or the foreground red theme in various native apps such as HealthKit.
+  ///
+  /// This is SystemRed in the iOS palette.
   static const Color destructiveRed = Color(0xFFFF3B30);
 }

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

@@ -4,7 +4,7 @@
 
 import 'package:flutter/widgets.dart';
 
-import 'colors.dart';
+import 'theme.dart';
 
 /// Implements a single iOS application page's layout.
 ///
@@ -21,7 +21,7 @@ class CupertinoPageScaffold extends StatelessWidget {
   const CupertinoPageScaffold({
     Key key,
     this.navigationBar,
-    this.backgroundColor = CupertinoColors.white,
+    this.backgroundColor,
     this.resizeToAvoidBottomInset = true,
     @required this.child,
   }) : assert(child != null),
@@ -48,7 +48,7 @@ class CupertinoPageScaffold extends StatelessWidget {
 
   /// The color of the widget that underlies the entire scaffold.
   ///
-  /// By default uses [CupertinoColors.white] color.
+  /// By default uses [CupertinoTheme]'s `scaffoldBackgroundColor` when null.
   final Color backgroundColor;
 
   /// Whether the [child] should size itself to avoid the window's bottom inset.
@@ -78,10 +78,13 @@ class CupertinoPageScaffold extends StatelessWidget {
           ? existingMediaQuery.viewInsets.bottom
           : 0.0;
 
+      final bool fullObstruction =
+        navigationBar.fullObstruction ?? CupertinoTheme.of(context).barBackgroundColor.alpha == 0xFF;
+
       // If navigation bar is opaquely obstructing, directly shift the main content
       // down. If translucent, let main content draw behind navigation bar but hint the
       // obstructed area.
-      if (navigationBar.fullObstruction) {
+      if (fullObstruction) {
         paddedContent = Padding(
           padding: EdgeInsets.only(top: topPadding, bottom: bottomPadding),
           child: child,
@@ -114,7 +117,9 @@ class CupertinoPageScaffold extends StatelessWidget {
     }
 
     return DecoratedBox(
-      decoration: BoxDecoration(color: backgroundColor),
+      decoration: BoxDecoration(
+        color: backgroundColor ?? CupertinoTheme.of(context).scaffoldBackgroundColor,
+      ),
       child: Stack(
         children: stacked,
       ),

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

@@ -9,7 +9,7 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
-import 'colors.dart';
+import 'theme.dart';
 import 'thumb_painter.dart';
 
 // Examples can assume:
@@ -189,7 +189,7 @@ class CupertinoSlider extends StatefulWidget {
 
   /// The color to use for the portion of the slider that has been selected.
   ///
-  /// Defaults to [CupertinoColors.activeBlue].
+  /// Defaults to the [CupertinoTheme]'s primary color if null.
   final Color activeColor;
 
   @override
@@ -228,7 +228,7 @@ class _CupertinoSliderState extends State<CupertinoSlider> with TickerProviderSt
     return _CupertinoSliderRenderObjectWidget(
       value: (widget.value - widget.min) / (widget.max - widget.min),
       divisions: widget.divisions,
-      activeColor: widget.activeColor ?? CupertinoColors.activeBlue,
+      activeColor: widget.activeColor ?? CupertinoTheme.of(context).primaryColor,
       onChanged: widget.onChanged != null ? _handleChanged : null,
       onChangeStart: widget.onChangeStart != null ? _handleDragStart : null,
       onChangeEnd: widget.onChangeEnd != null ? _handleDragEnd : null,
@@ -485,15 +485,14 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
     final double trackActive = offset.dx + _thumbCenter;
 
     final Canvas canvas = context.canvas;
-    final Paint paint = Paint();
 
     if (visualPosition > 0.0) {
-      paint.color = rightColor;
+      final Paint paint = Paint()..color = rightColor;
       canvas.drawRRect(RRect.fromLTRBXY(trackLeft, trackTop, trackActive, trackBottom, 1.0, 1.0), paint);
     }
 
     if (visualPosition < 1.0) {
-      paint.color = leftColor;
+      final Paint paint = Paint()..color = leftColor;
       canvas.drawRRect(RRect.fromLTRBXY(trackActive, trackTop, trackRight, trackBottom, 1.0, 1.0), paint);
     }
 

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

@@ -88,7 +88,8 @@ class CupertinoSwitch extends StatefulWidget {
 
   /// The color to use when this switch is on.
   ///
-  /// Defaults to [CupertinoColors.activeGreen].
+  /// Defaults to [CupertinoColors.activeGreen] when null and ignores the
+  /// [CupertinoTheme] in accordance to native iOS behavior.
   final Color activeColor;
 
   @override

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

@@ -4,6 +4,7 @@
 
 import 'package:flutter/widgets.dart';
 import 'bottom_tab_bar.dart';
+import 'theme.dart';
 
 /// Implements a tabbed iOS application's root layout and behavior structure.
 ///
@@ -173,13 +174,13 @@ class _CupertinoTabScaffoldState extends State<CupertinoTabScaffold> {
 
       // TODO(xster): Use real size after partial layout instead of preferred size.
       // https://github.com/flutter/flutter/issues/12912
-      final double bottomPadding = widget.tabBar.preferredSize.height
-          + existingMediaQuery.padding.bottom;
+      final double bottomPadding =
+          widget.tabBar.preferredSize.height + existingMediaQuery.padding.bottom;
 
       // If tab bar opaque, directly stop the main content higher. If
       // translucent, let main content draw behind the tab bar but hint the
       // obstructed area.
-      if (widget.tabBar.opaque) {
+      if (widget.tabBar.opaque(context)) {
         content = Padding(
           padding: EdgeInsets.only(bottom: bottomPadding),
           child: content,
@@ -219,8 +220,13 @@ class _CupertinoTabScaffoldState extends State<CupertinoTabScaffold> {
       ));
     }
 
-    return Stack(
-      children: stacked,
+    return DecoratedBox(
+      decoration: BoxDecoration(
+        color: CupertinoTheme.of(context).scaffoldBackgroundColor
+      ),
+      child: Stack(
+        children: stacked,
+      ),
     );
   }
 }

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

@@ -11,6 +11,7 @@ import 'package:flutter/widgets.dart';
 import 'colors.dart';
 import 'icons.dart';
 import 'text_selection.dart';
+import 'theme.dart';
 
 export 'package:flutter/services.dart' show TextInputType, TextInputAction, TextCapitalization;
 
@@ -32,15 +33,6 @@ const BoxDecoration _kDefaultRoundedBorderDecoration = BoxDecoration(
   borderRadius: BorderRadius.all(Radius.circular(4.0)),
 );
 
-// Default iOS style from HIG specs with larger font.
-const TextStyle _kDefaultTextStyle = TextStyle(
-  fontFamily: '.SF Pro Text',
-  fontSize: 17.0,
-  letterSpacing: -0.38,
-  color: CupertinoColors.black,
-  decoration: TextDecoration.none,
-);
-
 // Value extracted via color reader from iOS simulator.
 const Color _kSelectionHighlightColor = Color(0x667FAACF);
 const Color _kInactiveTextColor = Color(0xFFC2C2C2);
@@ -160,7 +152,7 @@ class CupertinoTextField extends StatefulWidget {
     TextInputType keyboardType,
     this.textInputAction,
     this.textCapitalization = TextCapitalization.none,
-    this.style = _kDefaultTextStyle,
+    this.style,
     this.textAlign = TextAlign.start,
     this.autofocus = false,
     this.obscureText = false,
@@ -271,7 +263,7 @@ class CupertinoTextField extends StatefulWidget {
   ///
   /// Also serves as a base for the [placeholder] text's style.
   ///
-  /// Defaults to a standard iOS style and cannot be null.
+  /// Defaults to the standard iOS font style from [CupertinoTheme] if null.
   final TextStyle style;
 
   /// {@macro flutter.widgets.editableText.textAlign}
@@ -558,7 +550,9 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
     );
   }
 
-  Widget _addTextDependentAttachments(Widget editableText) {
+  Widget _addTextDependentAttachments(Widget editableText, TextStyle textStyle) {
+    assert(editableText != null);
+    assert(textStyle != null);
     // If there are no surrounding widgets, just return the core editable text
     // part.
     if (widget.placeholder == null &&
@@ -593,7 +587,7 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
                 widget.placeholder,
                 maxLines: 1,
                 overflow: TextOverflow.ellipsis,
-                style: widget.style.merge(
+                style: textStyle.merge(
                   const TextStyle(
                     color: _kInactiveTextColor,
                     fontWeight: FontWeight.w300,
@@ -637,14 +631,13 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
   Widget build(BuildContext context) {
     super.build(context); // See AutomaticKeepAliveClientMixin.
     assert(debugCheckHasDirectionality(context));
-    final Brightness keyboardAppearance = widget.keyboardAppearance;
     final TextEditingController controller = _effectiveController;
-    final FocusNode focusNode = _effectiveFocusNode;
     final List<TextInputFormatter> formatters = widget.inputFormatters ?? <TextInputFormatter>[];
     final bool enabled = widget.enabled ?? true;
     if (widget.maxLength != null && widget.maxLengthEnforced) {
       formatters.add(LengthLimitingTextInputFormatter(widget.maxLength));
     }
+    final TextStyle textStyle = widget.style ?? CupertinoTheme.of(context).textTheme.textStyle;
 
     final Widget paddedEditable = Padding(
       padding: widget.padding,
@@ -652,11 +645,11 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
         child: EditableText(
           key: _editableTextKey,
           controller: controller,
-          focusNode: focusNode,
+          focusNode: _effectiveFocusNode,
           keyboardType: widget.keyboardType,
           textInputAction: widget.textInputAction,
           textCapitalization: widget.textCapitalization,
-          style: widget.style,
+          style: textStyle,
           textAlign: widget.textAlign,
           autofocus: widget.autofocus,
           obscureText: widget.obscureText,
@@ -674,7 +667,7 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
           cursorColor: widget.cursorColor,
           backgroundCursorColor: CupertinoColors.inactiveGray,
           scrollPadding: widget.scrollPadding,
-          keyboardAppearance: keyboardAppearance,
+          keyboardAppearance: widget.keyboardAppearance,
         ),
       ),
     );
@@ -692,14 +685,18 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
           decoration: widget.decoration,
           // The main decoration and the disabled scrim exists separately.
           child: Container(
-            color: enabled ? null : _kDisabledBackground,
+            color: enabled
+                ? null
+                : CupertinoTheme.of(context).brightness == Brightness.light
+                    ? _kDisabledBackground
+                    : CupertinoColors.darkBackgroundGray,
             child: GestureDetector(
               behavior: HitTestBehavior.translucent,
               onTapDown: _handleTapDown,
               onTapUp: _handleTapUp,
               onLongPress: _handleLongPress,
               excludeFromSemantics: true,
-              child: _addTextDependentAttachments(paddedEditable),
+              child: _addTextDependentAttachments(paddedEditable, textStyle),
             ),
           ),
         ),

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

+// 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/foundation.dart';
+import 'package:flutter/services.dart' show Brightness;
+import 'package:flutter/widgets.dart';
+
+import 'colors.dart';
+
+// Values derived from https://developer.apple.com/design/resources/.
+const TextStyle _kDefaultLightTextStyle = TextStyle(
+  inherit: false,
+  fontFamily: '.SF Pro Text',
+  fontSize: 17.0,
+  letterSpacing: -0.41,
+  color: CupertinoColors.black,
+  decoration: TextDecoration.none,
+);
+
+// Values derived from https://developer.apple.com/design/resources/.
+const TextStyle _kDefaultDarkTextStyle = TextStyle(
+  inherit: false,
+  fontFamily: '.SF Pro Text',
+  fontSize: 17.0,
+  letterSpacing: -0.41,
+  color: CupertinoColors.white,
+  decoration: TextDecoration.none,
+);
+
+// Values derived from https://developer.apple.com/design/resources/.
+const TextStyle _kDefaultActionTextStyle = TextStyle(
+  inherit: false,
+  fontFamily: '.SF Pro Text',
+  fontSize: 17.0,
+  letterSpacing: -0.41,
+  color: CupertinoColors.activeBlue,
+  decoration: TextDecoration.none,
+);
+
+// Values derived from https://developer.apple.com/design/resources/.
+const TextStyle _kDefaultTabLabelTextStyle = TextStyle(
+  inherit: false,
+  fontFamily: '.SF Pro Text',
+  fontSize: 10.0,
+  letterSpacing: -0.24,
+  color: CupertinoColors.inactiveGray,
+);
+
+const TextStyle _kDefaultMiddleTitleLightTextStyle = TextStyle(
+  inherit: false,
+  fontFamily: '.SF Pro Text',
+  fontSize: 17.0,
+  fontWeight: FontWeight.w600,
+  letterSpacing: -0.41,
+  color: CupertinoColors.black,
+);
+
+const TextStyle _kDefaultMiddleTitleDarkTextStyle = TextStyle(
+  inherit: false,
+  fontFamily: '.SF Pro Text',
+  fontSize: 17.0,
+  fontWeight: FontWeight.w600,
+  letterSpacing: -0.41,
+  color: CupertinoColors.white,
+);
+
+const TextStyle _kDefaultLargeTitleLightTextStyle = TextStyle(
+  inherit: false,
+  fontFamily: '.SF Pro Display',
+  fontSize: 34.0,
+  fontWeight: FontWeight.w700,
+  letterSpacing: 0.41,
+  color: CupertinoColors.black,
+);
+
+const TextStyle _kDefaultLargeTitleDarkTextStyle = TextStyle(
+  inherit: false,
+  fontFamily: '.SF Pro Display',
+  fontSize: 34.0,
+  fontWeight: FontWeight.w700,
+  letterSpacing: 0.41,
+  color: CupertinoColors.white,
+);
+
+/// Cupertino typography theme in a [CupertinoThemeData].
+@immutable
+class CupertinoTextThemeData extends Diagnosticable {
+  /// Create a [CupertinoTextThemeData].
+  ///
+  /// The [primaryColor] and [isLight] parameters are used to derive TextStyle
+  /// defaults of other attributes such as [textStyle] and [actionTextStyle]
+  /// etc. The default value of [primaryColor] is [CupertinoColors.activeBlue]
+  /// and the default value of [isLight] is true.
+  ///
+  /// Other [TextStyle] parameters default to default iOS text styles when
+  /// unspecified.
+  const CupertinoTextThemeData({
+    Color primaryColor,
+    Brightness brightness,
+    TextStyle textStyle,
+    TextStyle actionTextStyle,
+    TextStyle tabLabelTextStyle,
+    TextStyle navTitleTextStyle,
+    TextStyle navLargeTitleTextStyle,
+    TextStyle navActionTextStyle,
+  }) : _primaryColor = primaryColor ?? CupertinoColors.activeBlue,
+       _brightness = brightness,
+       _textStyle = textStyle,
+       _actionTextStyle = actionTextStyle,
+       _tabLabelTextStyle = tabLabelTextStyle,
+       _navTitleTextStyle = navTitleTextStyle,
+       _navLargeTitleTextStyle = navLargeTitleTextStyle,
+       _navActionTextStyle = navActionTextStyle;
+
+  final Color _primaryColor;
+  final Brightness _brightness;
+  bool get _isLight => _brightness != Brightness.dark;
+
+  final TextStyle _textStyle;
+  /// Typography of general text content for Cupertino widgets.
+  TextStyle get textStyle => _textStyle ?? (_isLight ? _kDefaultLightTextStyle : _kDefaultDarkTextStyle);
+
+  final TextStyle _actionTextStyle;
+  /// Typography of interactive text content such as text in a button without background.
+  TextStyle get actionTextStyle {
+    return _actionTextStyle ?? _kDefaultActionTextStyle.copyWith(
+      color: _primaryColor,
+    );
+  }
+
+  final TextStyle _tabLabelTextStyle;
+  /// Typography of unselected tabs.
+  TextStyle get tabLabelTextStyle => _tabLabelTextStyle ?? _kDefaultTabLabelTextStyle;
+
+  final TextStyle _navTitleTextStyle;
+  /// Typography of titles in standard navigation bars.
+  TextStyle get navTitleTextStyle {
+    return _navTitleTextStyle ??
+        (_isLight ? _kDefaultMiddleTitleLightTextStyle : _kDefaultMiddleTitleDarkTextStyle);
+  }
+
+  final TextStyle _navLargeTitleTextStyle;
+  /// Typography of large titles in sliver navigation bars.
+  TextStyle get navLargeTitleTextStyle {
+    return _navLargeTitleTextStyle ??
+        (_isLight ? _kDefaultLargeTitleLightTextStyle : _kDefaultLargeTitleDarkTextStyle);
+  }
+
+  final TextStyle _navActionTextStyle;
+  /// Typography of interative text content in navigation bars.
+  TextStyle get navActionTextStyle {
+    return _navActionTextStyle ?? _kDefaultActionTextStyle.copyWith(
+      color: _primaryColor,
+    );
+  }
+
+  /// Returns a copy of the current [CupertinoTextThemeData] instance with
+  /// specified overrides.
+  CupertinoTextThemeData copyWith({
+    Color primaryColor,
+    Brightness brightness,
+    TextStyle textStyle,
+    TextStyle actionTextStyle,
+    TextStyle tabLabelTextStyle,
+    TextStyle navTitleTextStyle,
+    TextStyle navLargeTitleTextStyle,
+    TextStyle navActionTextStyle,
+  }) {
+    return CupertinoTextThemeData(
+      primaryColor: primaryColor ?? _primaryColor,
+      brightness: brightness ?? _brightness,
+      textStyle: textStyle ?? _textStyle,
+      actionTextStyle: actionTextStyle ?? _actionTextStyle,
+      tabLabelTextStyle: tabLabelTextStyle ?? _tabLabelTextStyle,
+      navTitleTextStyle: navTitleTextStyle ?? _navTitleTextStyle,
+      navLargeTitleTextStyle: navLargeTitleTextStyle ?? _navLargeTitleTextStyle,
+      navActionTextStyle: navActionTextStyle ?? _navActionTextStyle,
+    );
+  }
+}

packages/flutter/lib/src/material/app.dart

@@ -443,7 +443,7 @@ class _MaterialAppState extends State<MaterialApp> {
             mini: true,
           );
         },
-      )
+      ),
     );
 
     assert(() {

packages/flutter/lib/src/material/theme.dart

@@ -2,6 +2,7 @@
 // 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/foundation.dart';
 import 'package:flutter/widgets.dart';
 
@@ -143,7 +144,15 @@ class Theme extends StatelessWidget {
       theme: this,
       child: IconTheme(
         data: data.iconTheme,
-        child: child,
+        child: CupertinoTheme(
+          // We're using a MaterialBasedCupertinoThemeData here instead of a
+          // CupertinoThemeData because it defers some properties to the Material
+          // ThemeData.
+          data: MaterialBasedCupertinoThemeData(
+            materialTheme: data,
+          ),
+          child: child,
+        ),
       ),
     );
   }

packages/flutter/lib/src/material/theme_data.dart

@@ -4,6 +4,7 @@
 
 import 'dart:ui' show Color, hashValues;
 
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
@@ -153,6 +154,7 @@ class ThemeData extends Diagnosticable {
     ColorScheme colorScheme,
     DialogTheme dialogTheme,
     Typography typography,
+    CupertinoThemeData cupertinoOverrideTheme
   }) {
     brightness ??= Brightness.light;
     final bool isDark = brightness == Brightness.dark;
@@ -246,6 +248,7 @@ class ThemeData extends Diagnosticable {
       labelStyle: textTheme.body2,
     );
     dialogTheme ??= const DialogTheme();
+    cupertinoOverrideTheme = cupertinoOverrideTheme?.noDefault();
 
     return ThemeData.raw(
       brightness: brightness,
@@ -294,11 +297,13 @@ class ThemeData extends Diagnosticable {
       colorScheme: colorScheme,
       dialogTheme: dialogTheme,
       typography: typography,
+      cupertinoOverrideTheme: cupertinoOverrideTheme,
     );
   }
 
-  /// Create a [ThemeData] given a set of exact values. All the values
-  /// must be specified.
+  /// Create a [ThemeData] given a set of exact values. All the values must be
+  /// specified. They all must also be non-null except for
+  /// [cupertinoOverrideTheme].
   ///
   /// This will rarely be used directly. It is used by [lerp] to
   /// create intermediate themes based on two themes created with the
@@ -353,6 +358,7 @@ class ThemeData extends Diagnosticable {
     @required this.colorScheme,
     @required this.dialogTheme,
     @required this.typography,
+    @required this.cupertinoOverrideTheme,
   }) : assert(brightness != null),
        assert(primaryColor != null),
        assert(primaryColorBrightness != null),
@@ -630,6 +636,18 @@ class ThemeData extends Diagnosticable {
   /// [primaryTextTheme], and [accentTextTheme].
   final Typography typography;
 
+  /// Components of the [CupertinoThemeData] to override from the Material
+  /// [ThemeData] adaptation.
+  ///
+  /// By default, [cupertinoOverrideTheme] is null and Cupertino widgets
+  /// descendant to the Material [Theme] will adhere to a [CupertinoTheme]
+  /// derived from the Material [ThemeData]. e.g. [ThemeData]'s [ColorTheme]
+  /// will also inform the [CupertinoThemeData]'s `primaryColor` etc.
+  ///
+  /// This cascading effect for individual attributes of the [CupertinoThemeData]
+  /// can be overridden using attributes of this [cupertinoOverrideTheme].
+  final CupertinoThemeData cupertinoOverrideTheme;
+
   /// Creates a copy of this theme but with the given fields replaced with the new values.
   ThemeData copyWith({
     Brightness brightness,
@@ -678,7 +696,9 @@ class ThemeData extends Diagnosticable {
     ColorScheme colorScheme,
     DialogTheme dialogTheme,
     Typography typography,
+    CupertinoThemeData cupertinoOverrideTheme,
   }) {
+    cupertinoOverrideTheme = cupertinoOverrideTheme?.noDefault();
     return ThemeData.raw(
       brightness: brightness ?? this.brightness,
       primaryColor: primaryColor ?? this.primaryColor,
@@ -726,6 +746,7 @@ class ThemeData extends Diagnosticable {
       colorScheme: colorScheme ?? this.colorScheme,
       dialogTheme: dialogTheme ?? this.dialogTheme,
       typography: typography ?? this.typography,
+      cupertinoOverrideTheme: cupertinoOverrideTheme ?? this.cupertinoOverrideTheme,
     );
   }
 
@@ -853,6 +874,7 @@ class ThemeData extends Diagnosticable {
       colorScheme: ColorScheme.lerp(a.colorScheme, b.colorScheme, t),
       dialogTheme: DialogTheme.lerp(a.dialogTheme, b.dialogTheme, t),
       typography: Typography.lerp(a.typography, b.typography, t),
+      cupertinoOverrideTheme: t < 0.5 ? a.cupertinoOverrideTheme : b.cupertinoOverrideTheme,
     );
   }
 
@@ -909,7 +931,8 @@ class ThemeData extends Diagnosticable {
            (otherData.pageTransitionsTheme == pageTransitionsTheme) &&
            (otherData.colorScheme == colorScheme) &&
            (otherData.dialogTheme == dialogTheme) &&
-           (otherData.typography == typography);
+           (otherData.typography == typography) &&
+           (otherData.cupertinoOverrideTheme == cupertinoOverrideTheme);
   }
 
   @override
@@ -967,6 +990,7 @@ class ThemeData extends Diagnosticable {
           colorScheme,
           dialogTheme,
           typography,
+          cupertinoOverrideTheme,
         ),
       ),
     );
@@ -1019,6 +1043,109 @@ class ThemeData extends Diagnosticable {
     properties.add(DiagnosticsProperty<ColorScheme>('colorScheme', colorScheme, defaultValue: defaultData.colorScheme));
     properties.add(DiagnosticsProperty<DialogTheme>('dialogTheme', dialogTheme, defaultValue: defaultData.dialogTheme));
     properties.add(DiagnosticsProperty<Typography>('typography', typography, defaultValue: defaultData.typography));
+    properties.add(DiagnosticsProperty<CupertinoThemeData>('cupertinoOverrideTheme', cupertinoOverrideTheme, defaultValue: defaultData.cupertinoOverrideTheme));
+  }
+}
+
+/// A [CupertinoThemeData] that defers unspecified theme attributes to an
+/// upstream Material [ThemeData].
+///
+/// This type of [CupertinoThemeData] is used by the Material [Theme] to
+/// harmonize the [CupertinoTheme] with the material theme's colors and text
+/// styles.
+///
+/// In the most basic case, [ThemeData]'s `cupertinoOverrideTheme` is null and
+/// and descendant Cupertino widgets' styling is derived from the Material theme.
+///
+/// To override individual parts of the Material-derived Cupertino styling,
+/// `cupertinoOverrideTheme`'s construction parameters can be used.
+///
+/// To completely decouple the Cupertino styling from Material theme derivation,
+/// another [CupertinoTheme] widget can be inserted as a descendant of the
+/// Material [Theme]. On a [MaterialApp], this can be done using the `builder`
+/// parameter on the constructor.
+///
+/// See also:
+///
+///  * [CupertinoThemeData], whose null constructor parameters default to
+///    reasonable iOS styling defaults rather than harmonizing with a Material
+///    theme.
+///  * [Theme], widget which inserts a [CupertinoTheme] with this
+///    [MaterialBasedCupertinoThemeData].
+// This class subclasses CupertinoThemeData rather than composes one because it
+// _is_ a CupertinoThemeData with partially altered behavior. e.g. its textTheme
+// is from the superclass and based on the primaryColor but the primaryColor
+// comes from the Material theme unless overridden.
+class MaterialBasedCupertinoThemeData extends CupertinoThemeData {
+  /// Create a [MaterialBasedCupertinoThemeData] based on a Material [ThemeData]
+  /// and its `cupertinoOverrideTheme`.
+  ///
+  /// The [materialTheme] parameter must not be null.
+  MaterialBasedCupertinoThemeData({
+    @required ThemeData materialTheme,
+  }) : assert(materialTheme != null),
+       _materialTheme = materialTheme,
+       // Pass all values to the superclass so Material-agnostic properties
+       // like barBackgroundColor can still behave like a normal
+       // CupertinoThemeData.
+       super.raw(
+         materialTheme.cupertinoOverrideTheme?.brightness,
+         materialTheme.cupertinoOverrideTheme?.primaryColor,
+         materialTheme.cupertinoOverrideTheme?.primaryContrastingColor,
+         materialTheme.cupertinoOverrideTheme?.textTheme,
+         materialTheme.cupertinoOverrideTheme?.barBackgroundColor,
+         materialTheme.cupertinoOverrideTheme?.scaffoldBackgroundColor,
+       );
+
+  final ThemeData _materialTheme;
+
+  @override
+  Brightness get brightness => _materialTheme.cupertinoOverrideTheme?.brightness ?? _materialTheme.brightness;
+
+  @override
+  Color get primaryColor => _materialTheme.cupertinoOverrideTheme?.primaryColor ?? _materialTheme.colorScheme.primary;
+
+  @override
+  Color get primaryContrastingColor => _materialTheme.cupertinoOverrideTheme?.primaryContrastingColor ?? _materialTheme.colorScheme.onPrimary;
+
+  @override
+  Color get scaffoldBackgroundColor => _materialTheme.cupertinoOverrideTheme?.scaffoldBackgroundColor ?? _materialTheme.scaffoldBackgroundColor;
+
+  /// Copies the [ThemeData]'s `cupertinoOverrideTheme`.
+  ///
+  /// Only the specified override attributes of the [ThemeData]'s
+  /// `cupertinoOverrideTheme` and the newly specified parameters are in the
+  /// returned [CupertinoThemeData]. No derived attributes from iOS defaults or
+  /// from cascaded Material theme attributes are copied.
+  ///
+  /// [MaterialBasedCupertinoThemeData.copyWith] cannot change the base
+  /// Material [ThemeData]. To change the base Material [ThemeData], create a
+  /// new Material [Theme] and use `copyWith` on the Material [ThemeData]
+  /// instead.
+  @override
+  CupertinoThemeData copyWith({
+    Brightness brightness,
+    Color primaryColor,
+    Color primaryContrastingColor,
+    CupertinoTextThemeData textTheme,
+    Color barBackgroundColor,
+    Color scaffoldBackgroundColor,
+  }) {
+    return _materialTheme.cupertinoOverrideTheme?.copyWith(
+      brightness: brightness,
+      primaryColor: primaryColor,
+      primaryContrastingColor: primaryContrastingColor,
+      textTheme: textTheme,
+      barBackgroundColor: barBackgroundColor,
+      scaffoldBackgroundColor: scaffoldBackgroundColor,
+    ) ?? CupertinoThemeData(
+      brightness: brightness,
+      primaryColor: primaryColor,
+      primaryContrastingColor: primaryContrastingColor,
+      textTheme: textTheme,
+      barBackgroundColor: barBackgroundColor,
+      scaffoldBackgroundColor: scaffoldBackgroundColor,
+    );
   }
 }
 

packages/flutter/lib/src/rendering/layer.dart

@@ -182,7 +182,7 @@ abstract class Layer extends AbstractNode with DiagnosticableTreeMixin {
     // Proof by contradiction:
     //
     // If we introduce a loop, this retained layer must be appended to one of
-    // its descendent layers, say A. That means the child structure of A has
+    // its descendant layers, say A. That means the child structure of A has
     // changed so A's _needsAddToScene is true. This contradicts
     // _subtreeNeedsAddToScene being false.
     if (!_subtreeNeedsAddToScene && _engineLayer != null) {

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

@@ -46,7 +46,7 @@ import 'framework.dart';
 ///
 /// When the inherited model is rebuilt the [updateShouldNotify] and
 /// [updateShouldNotifyDependent] methods are used to decide what
-/// should be rebuilt.  If [updateShouldNotify] returns true, then the
+/// should be rebuilt. If [updateShouldNotify] returns true, then the
 /// inherited model's [updateShouldNotifyDependent] method is tested for
 /// each dependent and the set of aspect objects it depends on.
 /// The [updateShouldNotifyDependent] method must compare the set of aspect
@@ -153,6 +153,8 @@ abstract class InheritedModel<T> extends InheritedWidget {
   ///
   /// If [aspect] is null this method is the same as
   /// `context.inheritFromWidgetOfExactType(T)`.
+  ///
+  /// If no ancestor of type T exists, null is returned.
   static T inheritFrom<T extends InheritedModel<Object>>(BuildContext context, { Object aspect }) {
     if (aspect == null)
       return context.inheritFromWidgetOfExactType(T);
@@ -160,6 +162,10 @@ abstract class InheritedModel<T> extends InheritedWidget {
     // Create a dependency on all of the type T ancestor models up until
     // a model is found for which isSupportedAspect(aspect) is true.
     final List<InheritedElement> models = _findModels<T>(context, aspect).toList();
+    if (models.isEmpty) {
+      return null;
+    }
+
     final InheritedElement lastModel = models.last;
     for (InheritedElement model in models) {
       final T value = context.inheritFromElement(model, aspect: aspect);

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

@@ -43,7 +43,7 @@ typedef ValueWidgetBuilder<T> = Widget Function(BuildContext context, T value, W
 ///  * [AnimatedBuilder], which also triggers rebuilds from a [Listenable]
 ///    without passing back a specific value from a [ValueListenable].
 ///  * [NotificationListener], which lets you rebuild based on [Notification]
-///    coming from its descendent widgets rather than a [ValueListenable] that
+///    coming from its descendant widgets rather than a [ValueListenable] that
 ///    you have a direct reference to.
 ///  * [StreamBuilder], where a builder can depend on a [Stream] rather than
 ///    a [ValueListenable] for more advanced use cases.

packages/flutter/test/cupertino/bottom_tab_bar_test.dart

@@ -68,6 +68,70 @@ void main() {
     expect(actualActive.text.style.color, const Color(0xFF123456));
   });
 
+  testWidgets('Tabs respects themes', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: CupertinoTabBar(
+          items: const <BottomNavigationBarItem>[
+            BottomNavigationBarItem(
+              icon: ImageIcon(TestImageProvider(24, 24)),
+              title: Text('Tab 1'),
+            ),
+            BottomNavigationBarItem(
+              icon: ImageIcon(TestImageProvider(24, 24)),
+              title: Text('Tab 2'),
+            ),
+          ],
+          currentIndex: 1,
+        ),
+      ),
+    );
+
+    RichText actualInactive = tester.widget(find.descendant(
+      of: find.text('Tab 1'),
+      matching: find.byType(RichText),
+    ));
+    expect(actualInactive.text.style.color, CupertinoColors.inactiveGray);
+
+    RichText actualActive = tester.widget(find.descendant(
+      of: find.text('Tab 2'),
+      matching: find.byType(RichText),
+    ));
+    expect(actualActive.text.style.color, CupertinoColors.activeBlue);
+
+    await tester.pumpWidget(
+      CupertinoApp(
+        theme: const CupertinoThemeData(brightness: Brightness.dark),
+        home: CupertinoTabBar(
+          items: const <BottomNavigationBarItem>[
+            BottomNavigationBarItem(
+              icon: ImageIcon(TestImageProvider(24, 24)),
+              title: Text('Tab 1'),
+            ),
+            BottomNavigationBarItem(
+              icon: ImageIcon(TestImageProvider(24, 24)),
+              title: Text('Tab 2'),
+            ),
+          ],
+          currentIndex: 1,
+        ),
+      ),
+    );
+
+    actualInactive = tester.widget(find.descendant(
+      of: find.text('Tab 1'),
+      matching: find.byType(RichText),
+    ));
+    expect(actualInactive.text.style.color, CupertinoColors.inactiveGray);
+
+    actualActive = tester.widget(find.descendant(
+      of: find.text('Tab 2'),
+      matching: find.byType(RichText),
+    ));
+    expect(actualActive.text.style.color, CupertinoColors.activeOrange);
+
+  });
+
   testWidgets('Use active icon', (WidgetTester tester) async {
     const TestImageProvider activeIcon = TestImageProvider(16, 16);
     const TestImageProvider inactiveIcon = TestImageProvider(24, 24);

packages/flutter/test/cupertino/button_test.dart

@@ -12,6 +12,7 @@ import '../widgets/semantics_tester.dart';
 const TextStyle testStyle = TextStyle(
   fontFamily: 'Ahem',
   fontSize: 10.0,
+  letterSpacing: 0.0,
 );
 
 void main() {
@@ -226,6 +227,80 @@ void main() {
 
     expect(boxDecoration.color, const Color(0x00FF00));
   });
+
+  testWidgets('Botton respects themes', (WidgetTester tester) async {
+    TextStyle textStyle;
+
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: CupertinoButton(
+          onPressed: () {},
+          child: Builder(builder: (BuildContext context) {
+            textStyle = DefaultTextStyle.of(context).style;
+            return const Placeholder();
+          }),
+        ),
+      ),
+    );
+
+    expect(textStyle.color, CupertinoColors.activeBlue);
+
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: CupertinoButton.filled(
+          onPressed: () {},
+          child: Builder(builder: (BuildContext context) {
+            textStyle = DefaultTextStyle.of(context).style;
+            return const Placeholder();
+          }),
+        ),
+      ),
+    );
+
+    expect(textStyle.color, CupertinoColors.white);
+    BoxDecoration decoration = tester.widget<DecoratedBox>(
+      find.descendant(
+        of: find.byType(CupertinoButton),
+        matching: find.byType(DecoratedBox)
+      )
+    ).decoration;
+    expect(decoration.color, CupertinoColors.activeBlue);
+
+    await tester.pumpWidget(
+      CupertinoApp(
+        theme: const CupertinoThemeData(brightness: Brightness.dark),
+        home: CupertinoButton(
+          onPressed: () {},
+          child: Builder(builder: (BuildContext context) {
+            textStyle = DefaultTextStyle.of(context).style;
+            return const Placeholder();
+          }),
+        ),
+      ),
+    );
+    expect(textStyle.color, CupertinoColors.activeOrange);
+
+    await tester.pumpWidget(
+      CupertinoApp(
+        theme: const CupertinoThemeData(brightness: Brightness.dark),
+        home: CupertinoButton.filled(
+          onPressed: () {},
+          child: Builder(builder: (BuildContext context) {
+            textStyle = DefaultTextStyle.of(context).style;
+            return const Placeholder();
+          }),
+        ),
+      ),
+    );
+    expect(textStyle.color, CupertinoColors.black);
+    decoration = tester.widget<DecoratedBox>(
+      find.descendant(
+        of: find.byType(CupertinoButton),
+        matching: find.byType(DecoratedBox)
+      )
+    ).decoration;
+    expect(decoration.color, CupertinoColors.activeOrange);
+  });
 }
 
 Widget boilerplate({ Widget child }) {

packages/flutter/test/cupertino/nav_bar_test.dart

@@ -148,15 +148,62 @@ void main() {
     expect(tester.getCenter(find.text('Title')).dx, 400.0);
   });
 
-  testWidgets('Verify styles of each slot', (WidgetTester tester) async {
+  testWidgets('Nav bar uses theme defaults', (WidgetTester tester) async {
     count = 0x000000;
     await tester.pumpWidget(
-      const CupertinoApp(
+      CupertinoApp(
+        home: CupertinoNavigationBar(
+          leading: CupertinoButton(
+            onPressed: () {},
+            child: const _ExpectStyles(color: CupertinoColors.activeBlue, index: 0x000001),
+          ),
+          middle: const _ExpectStyles(color: CupertinoColors.black, index: 0x000100),
+          trailing: CupertinoButton(
+            onPressed: () {},
+            child: const _ExpectStyles(color: CupertinoColors.activeBlue, index: 0x010000),
+          ),
+        ),
+      ),
+    );
+    expect(count, 0x010101);
+  });
+
+  testWidgets('Nav bar respects themes', (WidgetTester tester) async {
+    count = 0x000000;
+    await tester.pumpWidget(
+      CupertinoApp(
+        theme: const CupertinoThemeData(brightness: Brightness.dark),
         home: CupertinoNavigationBar(
-          leading: _ExpectStyles(color: Color(0xFF001122), index: 0x000001),
-          middle: _ExpectStyles(color: Color(0xFF000000), letterSpacing: -0.08, index: 0x000100),
-          trailing: _ExpectStyles(color: Color(0xFF001122), index: 0x010000),
-          actionsForegroundColor: Color(0xFF001122),
+          leading: CupertinoButton(
+            onPressed: () {},
+            child: const _ExpectStyles(color: CupertinoColors.activeOrange, index: 0x000001),
+          ),
+          middle: const _ExpectStyles(color: CupertinoColors.white, index: 0x000100),
+          trailing: CupertinoButton(
+            onPressed: () {},
+            child: const _ExpectStyles(color: CupertinoColors.activeOrange, index: 0x010000),
+          ),
+        ),
+      ),
+    );
+    expect(count, 0x010101);
+  });
+
+  testWidgets('Theme active color can be overriden', (WidgetTester tester) async {
+    count = 0x000000;
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: CupertinoNavigationBar(
+          leading: CupertinoButton(
+            onPressed: () {},
+            child: const _ExpectStyles(color: Color(0xFF001122), index: 0x000001),
+          ),
+          middle: const _ExpectStyles(color: Color(0xFF000000), index: 0x000100),
+          trailing: CupertinoButton(
+            onPressed: () {},
+            child: const _ExpectStyles(color: Color(0xFF001122), index: 0x010000),
+          ),
+          actionsForegroundColor: const Color(0xFF001122),
         ),
       ),
     );
@@ -845,18 +892,18 @@ void main() {
 }
 
 class _ExpectStyles extends StatelessWidget {
-  const _ExpectStyles({ this.color, this.letterSpacing, this.index });
+  const _ExpectStyles({ this.color, this.index });
 
   final Color color;
-  final double letterSpacing;
   final int index;
 
   @override
   Widget build(BuildContext context) {
     final TextStyle style = DefaultTextStyle.of(context).style;
     expect(style.color, color);
+    expect(style.fontFamily, '.SF Pro Text');
     expect(style.fontSize, 17.0);
-    expect(style.letterSpacing, letterSpacing ?? -0.24);
+    expect(style.letterSpacing, -0.41);
     count += index;
     return Container();
   }

packages/flutter/test/cupertino/segmented_control_test.dart

@@ -142,7 +142,7 @@ void main() {
     }
   });
 
-  testWidgets('Children, onValueChanged, and color arguments can not be null',
+  testWidgets('Children and onValueChanged arguments can not be null',
           (WidgetTester tester) async {
     try {
       await tester.pumpWidget(
@@ -175,21 +175,6 @@ void main() {
     } on AssertionError catch (e) {
       expect(e.toString(), contains('onValueChanged'));
     }
-
-    try {
-      await tester.pumpWidget(
-        boilerplate(
-          child: CupertinoSegmentedControl<int>(
-            children: children,
-            onValueChanged: (int newValue) {},
-            unselectedColor: null,
-          ),
-        ),
-      );
-      fail('Should not be possible to create segmented control with null unselectedColor');
-    } on AssertionError catch (e) {
-      expect(e.toString(), contains('unselectedColor'));
-    }
   });
 
   testWidgets('Widgets have correct default text/icon styles, change correctly on selection',
@@ -236,6 +221,52 @@ void main() {
     expect(iconTheme.data.color, CupertinoColors.white);
   });
 
+  testWidgets(
+    'Segmented controls respects themes',
+    (WidgetTester tester) async {
+      final Map<int, Widget> children = <int, Widget>{};
+      children[0] = const Text('Child 1');
+      children[1] = const Icon(IconData(1));
+
+      int sharedValue = 0;
+
+      await tester.pumpWidget(
+        CupertinoApp(
+          theme: const CupertinoThemeData(brightness: Brightness.dark),
+          home: StatefulBuilder(
+            builder: (BuildContext context, StateSetter setState) {
+              return CupertinoSegmentedControl<int>(
+                children: children,
+                onValueChanged: (int newValue) {
+                  setState(() {
+                    sharedValue = newValue;
+                  });
+                },
+                groupValue: sharedValue,
+              );
+            },
+          ),
+        ),
+      );
+
+      DefaultTextStyle textStyle = tester.widget(find.widgetWithText(DefaultTextStyle, 'Child 1').first);
+      IconTheme iconTheme = tester.widget(find.widgetWithIcon(IconTheme, const IconData(1)));
+
+      expect(textStyle.style.color, CupertinoColors.black);
+      expect(iconTheme.data.color, CupertinoColors.activeOrange);
+
+      await tester.tap(find.widgetWithIcon(IconTheme, const IconData(1)));
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 500));
+
+      textStyle = tester.widget(find.widgetWithText(DefaultTextStyle, 'Child 1').first);
+      iconTheme = tester.widget(find.widgetWithIcon(IconTheme, const IconData(1)));
+
+      expect(textStyle.style.color, CupertinoColors.activeOrange);
+      expect(iconTheme.data.color, CupertinoColors.black);
+    },
+  );
+
   testWidgets('SegmentedControl is correct when user provides custom colors',
           (WidgetTester tester) async {
     final Map<int, Widget> children = <int, Widget>{};
@@ -1171,13 +1202,13 @@ void main() {
     await tester.tap(find.text('B'));
 
     await tester.pump();
-    expect(getBackgroundColor(tester, 0), const Color(0xff007aff));
-    expect(getBackgroundColor(tester, 1), const Color(0x33007aff));
+    expect(getBackgroundColor(tester, 0), CupertinoColors.white);
+    expect(getBackgroundColor(tester, 1), CupertinoColors.activeBlue);
     expect(getBackgroundColor(tester, 3), CupertinoColors.white);
 
     await tester.pump(const Duration(milliseconds: 40));
-    expect(getBackgroundColor(tester, 0), const Color(0xff3d9aff));
-    expect(getBackgroundColor(tester, 1), const Color(0x64007aff));
+    expect(getBackgroundColor(tester, 0), CupertinoColors.white);
+    expect(getBackgroundColor(tester, 1), CupertinoColors.activeBlue);
     expect(getBackgroundColor(tester, 3), CupertinoColors.white);
 
     await tester.pump(const Duration(milliseconds: 150));

packages/flutter/test/cupertino/slider_test.dart

@@ -8,6 +8,7 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+import '../rendering/mock_canvas.dart';
 import '../widgets/semantics_tester.dart';
 
 void main() {
@@ -359,4 +360,57 @@ void main() {
 
     handle.dispose();
   });
+
+  testWidgets('Slider respects themes', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: Center(
+          child: CupertinoSlider(
+            onChanged: (double value) {},
+            value: 0.5,
+          ),
+        ),
+      ),
+    );
+    expect(
+      find.byType(CupertinoSlider),
+      // First line it paints is blue.
+      paints..rrect(color: CupertinoColors.activeBlue),
+    );
+
+    await tester.pumpWidget(
+      CupertinoApp(
+        theme: const CupertinoThemeData(brightness: Brightness.dark),
+        home: Center(
+          child: CupertinoSlider(
+            onChanged: (double value) {},
+            value: 0.5,
+          ),
+        ),
+      ),
+    );
+    expect(
+      find.byType(CupertinoSlider),
+      paints..rrect(color: CupertinoColors.activeOrange),
+    );
+  });
+
+  testWidgets('Themes can be overridden', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      CupertinoApp(
+        theme: const CupertinoThemeData(brightness: Brightness.dark),
+        home: Center(
+          child: CupertinoSlider(
+            activeColor: CupertinoColors.activeGreen,
+            onChanged: (double value) {},
+            value: 0.5,
+          ),
+        ),
+      ),
+    );
+    expect(
+      find.byType(CupertinoSlider),
+      paints..rrect(color: CupertinoColors.activeGreen),
+    );
+  });
 }

packages/flutter/test/cupertino/tab_scaffold_test.dart

@@ -254,6 +254,64 @@ void main() {
     expect(tabsPainted, <int>[0, 1, 0]);
     expect(selectedTabs, <int>[0]);
   });
+
+  testWidgets('Tab bar respects themes', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: CupertinoTabScaffold(
+          tabBar: _buildTabBar(),
+          tabBuilder: (BuildContext context, int index) {
+            return const Placeholder();
+          },
+        ),
+      ),
+    );
+
+    BoxDecoration tabDecoration = tester.widget<DecoratedBox>(find.descendant(
+      of: find.byType(CupertinoTabBar),
+      matching: find.byType(DecoratedBox),
+    )).decoration;
+
+    expect(tabDecoration.color, const Color(0xCCF8F8F8));
+
+    await tester.tap(find.text('Tab 2'));
+    await tester.pump();
+
+    // Pump again but with dark theme.
+    await tester.pumpWidget(
+      CupertinoApp(
+        theme: const CupertinoThemeData(
+          brightness: Brightness.dark,
+          primaryColor: CupertinoColors.destructiveRed,
+        ),
+        home: CupertinoTabScaffold(
+          tabBar: _buildTabBar(),
+          tabBuilder: (BuildContext context, int index) {
+            return const Placeholder();
+          },
+        ),
+      ),
+    );
+
+    tabDecoration = tester.widget<DecoratedBox>(find.descendant(
+      of: find.byType(CupertinoTabBar),
+      matching: find.byType(DecoratedBox),
+    )).decoration;
+
+    expect(tabDecoration.color, const Color(0xB7212121));
+
+    final RichText tab1 = tester.widget(find.descendant(
+      of: find.text('Tab 1'),
+      matching: find.byType(RichText),
+    ));
+    // Tab 2 should still be selected after changing theme.
+    expect(tab1.text.style.color, CupertinoColors.inactiveGray);
+    final RichText tab2 = tester.widget(find.descendant(
+      of: find.text('Tab 2'),
+      matching: find.byType(RichText),
+    ));
+    expect(tab2.text.style.color, CupertinoColors.destructiveRed);
+  });
 }
 
 CupertinoTabBar _buildTabBar({ int selectedTab = 0 }) {
@@ -268,7 +326,6 @@ CupertinoTabBar _buildTabBar({ int selectedTab = 0 }) {
         title: Text('Tab 2'),
       ),
     ],
-    backgroundColor: CupertinoColors.white,
     currentIndex: selectedTab,
     onTap: (int newTab) => selectedTabs.add(newTab),
   );

packages/flutter/test/cupertino/text_field_test.dart

@@ -1098,4 +1098,42 @@ void main() {
       expect(find.byType(CupertinoButton), findsNWidgets(3));
     },
   );
+
+  testWidgets(
+    'text field respects theme',
+    (WidgetTester tester) async {
+      await tester.pumpWidget(
+        const CupertinoApp(
+          theme: CupertinoThemeData(
+            brightness: Brightness.dark,
+          ),
+          home: Center(
+            child: CupertinoTextField(),
+          ),
+        ),
+      );
+
+      final BoxDecoration decoration = tester.widget<DecoratedBox>(
+        find.descendant(
+          of: find.byType(CupertinoTextField),
+          matching: find.byType(DecoratedBox)
+        ),
+      ).decoration;
+
+      expect(
+        decoration.border.bottom.color,
+        CupertinoColors.lightBackgroundGray, // Border color is the same regardless.
+      );
+
+      await tester.enterText(find.byType(CupertinoTextField), 'smoked meat');
+      await tester.pump();
+
+      expect(
+        tester.renderObject<RenderEditable>(
+          find.byElementPredicate((Element element) => element.renderObject is RenderEditable)
+        ).text.style.color,
+        CupertinoColors.white,
+      );
+    },
+  );
 }

packages/flutter/test/cupertino/theme_test.dart

+// 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 'dart:async';
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+int buildCount;
+CupertinoThemeData actualTheme;
+
+final Widget singletonThemeSubtree = Builder(
+  builder: (BuildContext context) {
+    buildCount++;
+    actualTheme = CupertinoTheme.of(context);
+    return const Placeholder();
+  },
+);
+
+Future<CupertinoThemeData> testTheme(WidgetTester tester, CupertinoThemeData theme) async {
+  await tester.pumpWidget(
+    CupertinoTheme(
+      data: theme,
+      child: singletonThemeSubtree,
+    ),
+  );
+  return actualTheme;
+}
+
+void main() {
+  setUp(() {
+    buildCount = 0;
+    actualTheme = null;
+  });
+
+  testWidgets('Default theme has defaults', (WidgetTester tester) async {
+    final CupertinoThemeData theme = await testTheme(tester, const CupertinoThemeData());
+
+    expect(theme.brightness, Brightness.light);
+    expect(theme.primaryColor, CupertinoColors.activeBlue);
+    expect(theme.textTheme.textStyle.fontSize, 17.0);
+  });
+
+  testWidgets('Theme attributes cascade', (WidgetTester tester) async {
+    final CupertinoThemeData theme = await testTheme(tester, const CupertinoThemeData(
+      primaryColor: CupertinoColors.destructiveRed,
+    ));
+
+    expect(theme.textTheme.actionTextStyle.color, CupertinoColors.destructiveRed);
+  });
+
+  testWidgets('Dependent attribute can be overridden from cascaded value', (WidgetTester tester) async {
+    final CupertinoThemeData theme = await testTheme(tester, const CupertinoThemeData(
+      brightness: Brightness.dark,
+      textTheme: CupertinoTextThemeData(
+        textStyle: TextStyle(color: CupertinoColors.black),
+      )
+    ));
+
+    // The brightness still cascaded down to the background color.
+    expect(theme.scaffoldBackgroundColor, CupertinoColors.black);
+    // But not to the font color which we overrode.
+    expect(theme.textTheme.textStyle.color, CupertinoColors.black);
+  });
+
+  testWidgets(
+    'Reading themes creates dependencies',
+    (WidgetTester tester) async {
+      // Reading the theme creates a dependency.
+      CupertinoThemeData theme = await testTheme(tester, const CupertinoThemeData(
+        // Default brightness is light,
+        barBackgroundColor: Color(0x11223344),
+        textTheme: CupertinoTextThemeData(
+          textStyle: TextStyle(fontFamily: 'Skeuomorphic'),
+        ),
+      ));
+
+      expect(buildCount, 1);
+      expect(theme.textTheme.textStyle.fontFamily, 'Skeuomorphic');
+
+      // Changing another property also triggers a rebuild.
+      theme = await testTheme(tester, const CupertinoThemeData(
+        brightness: Brightness.light,
+        barBackgroundColor: Color(0x11223344),
+        textTheme: CupertinoTextThemeData(
+          textStyle: TextStyle(fontFamily: 'Skeuomorphic'),
+        ),
+      ));
+
+      expect(buildCount, 2);
+      // Re-reading the same value doesn't change anything.
+      expect(theme.textTheme.textStyle.fontFamily, 'Skeuomorphic');
+
+      theme = await testTheme(tester, const CupertinoThemeData(
+        brightness: Brightness.light,
+        barBackgroundColor: Color(0x11223344),
+        textTheme: CupertinoTextThemeData(
+          textStyle: TextStyle(fontFamily: 'Flat'),
+        ),
+      ));
+
+      expect(buildCount, 3);
+      expect(theme.textTheme.textStyle.fontFamily, 'Flat');
+    },
+  );
+
+  testWidgets(
+    'copyWith works',
+    (WidgetTester tester) async {
+      const CupertinoThemeData originalTheme = CupertinoThemeData(
+        brightness: Brightness.dark,
+      );
+
+      final CupertinoThemeData theme = await testTheme(tester, originalTheme.copyWith(
+        primaryColor: CupertinoColors.activeGreen,
+      ));
+
+      expect(theme.brightness, Brightness.dark);
+      expect(theme.primaryColor, CupertinoColors.activeGreen);
+      // Now check calculated derivatives.
+      expect(theme.textTheme.actionTextStyle.color, CupertinoColors.activeGreen);
+      expect(theme.scaffoldBackgroundColor, CupertinoColors.black);
+    },
+  );
+}

packages/flutter/test/material/theme_test.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:ui' as ui;
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/src/foundation/diagnostics.dart';
@@ -412,6 +413,227 @@ void main() {
 
     expect(theme.textTheme.display4.debugLabel, '(englishLike display4 2014).merge(blackMountainView display4)');
   });
+
+  group('Cupertino theme', () {
+    int buildCount;
+    CupertinoThemeData actualTheme;
+
+    final Widget singletonThemeSubtree = Builder(
+      builder: (BuildContext context) {
+        buildCount++;
+        actualTheme = CupertinoTheme.of(context);
+        return const Placeholder();
+      },
+    );
+
+    Future<CupertinoThemeData> testTheme(WidgetTester tester, ThemeData theme) async {
+      await tester.pumpWidget(
+        Theme(
+          data: theme,
+          child: singletonThemeSubtree,
+        ),
+      );
+      return actualTheme;
+    }
+
+    setUp(() {
+      buildCount = 0;
+      actualTheme = null;
+    });
+
+    testWidgets('Default theme has defaults', (WidgetTester tester) async {
+      final CupertinoThemeData theme = await testTheme(tester, ThemeData.light());
+
+      expect(theme.brightness, Brightness.light);
+      expect(theme.primaryColor, Colors.blue);
+      expect(theme.scaffoldBackgroundColor, Colors.grey[50]);
+      expect(theme.primaryContrastingColor, Colors.white);
+      expect(theme.textTheme.textStyle.fontFamily, '.SF Pro Text');
+      expect(theme.textTheme.textStyle.fontSize, 17.0);
+    });
+
+    testWidgets('Dark theme has defaults', (WidgetTester tester) async {
+      final CupertinoThemeData theme = await testTheme(tester, ThemeData.dark());
+
+      expect(theme.brightness, Brightness.dark);
+      expect(theme.primaryColor, Colors.blue);
+      expect(theme.primaryContrastingColor, Colors.white);
+      expect(theme.scaffoldBackgroundColor, Colors.grey[850]);
+      expect(theme.textTheme.textStyle.fontFamily, '.SF Pro Text');
+      expect(theme.textTheme.textStyle.fontSize, 17.0);
+    });
+
+    testWidgets('Can override material theme', (WidgetTester tester) async {
+      final CupertinoThemeData theme = await testTheme(tester, ThemeData(
+        cupertinoOverrideTheme: const CupertinoThemeData(
+          scaffoldBackgroundColor: CupertinoColors.lightBackgroundGray,
+        ),
+      ));
+
+      expect(theme.brightness, Brightness.light);
+      // We took the scaffold background override but the rest are still cascaded
+      // to the material theme.
+      expect(theme.primaryColor, Colors.blue);
+      expect(theme.primaryContrastingColor, Colors.white);
+      expect(theme.scaffoldBackgroundColor, CupertinoColors.lightBackgroundGray);
+      expect(theme.textTheme.textStyle.fontFamily, '.SF Pro Text');
+      expect(theme.textTheme.textStyle.fontSize, 17.0);
+    });
+
+    testWidgets('Can override properties that are independent of material', (WidgetTester tester) async {
+      final CupertinoThemeData theme = await testTheme(tester, ThemeData(
+        cupertinoOverrideTheme: const CupertinoThemeData(
+          // The bar colors ignore all things material except brightness.
+          barBackgroundColor: CupertinoColors.black,
+        ),
+      ));
+
+      expect(theme.primaryColor, Colors.blue);
+      // MaterialBasedCupertinoThemeData should also function like a normal CupertinoThemeData.
+      expect(theme.barBackgroundColor, CupertinoColors.black);
+    });
+
+    testWidgets('Changing material theme triggers rebuilds', (WidgetTester tester) async {
+      CupertinoThemeData theme = await testTheme(tester, ThemeData(
+        primarySwatch: Colors.red,
+      ));
+
+      expect(buildCount, 1);
+      expect(theme.primaryColor, Colors.red);
+
+      theme = await testTheme(tester, ThemeData(
+        primarySwatch: Colors.orange,
+      ));
+
+      expect(buildCount, 2);
+      expect(theme.primaryColor, Colors.orange);
+    });
+
+    testWidgets(
+      'Changing cupertino theme override triggers rebuilds',
+      (WidgetTester tester) async {
+        CupertinoThemeData theme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.purple,
+          cupertinoOverrideTheme: const CupertinoThemeData(
+            primaryColor: CupertinoColors.activeOrange,
+          ),
+        ));
+
+        expect(buildCount, 1);
+        expect(theme.primaryColor, CupertinoColors.activeOrange);
+
+        theme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.purple,
+          cupertinoOverrideTheme: const CupertinoThemeData(
+            primaryColor: CupertinoColors.activeGreen,
+          ),
+        ));
+
+        expect(buildCount, 2);
+        expect(theme.primaryColor, CupertinoColors.activeGreen);
+      },
+    );
+
+    testWidgets(
+      'Cupertino theme override blocks derivative changes',
+      (WidgetTester tester) async {
+        CupertinoThemeData theme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.purple,
+          cupertinoOverrideTheme: const CupertinoThemeData(
+            primaryColor: CupertinoColors.activeOrange,
+          ),
+        ));
+
+        expect(buildCount, 1);
+        expect(theme.primaryColor, CupertinoColors.activeOrange);
+
+        // Change the upstream material primary color.
+        theme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.blue,
+          cupertinoOverrideTheme: const CupertinoThemeData(
+            // But the primary material color is preempted by the override.
+            primaryColor: CupertinoColors.activeOrange,
+          ),
+        ));
+
+        expect(buildCount, 2);
+        expect(theme.primaryColor, CupertinoColors.activeOrange);
+      },
+    );
+
+    testWidgets(
+      'Cupertino overrides do not block derivatives triggering rebuilds when derivatives are not overridden',
+      (WidgetTester tester) async {
+        CupertinoThemeData theme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.purple,
+          cupertinoOverrideTheme: const CupertinoThemeData(
+            primaryContrastingColor: CupertinoColors.destructiveRed,
+          ),
+        ));
+
+        expect(buildCount, 1);
+        expect(theme.textTheme.actionTextStyle.color, Colors.purple);
+        expect(theme.primaryContrastingColor, CupertinoColors.destructiveRed);
+
+        theme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.green,
+          cupertinoOverrideTheme: const CupertinoThemeData(
+            primaryContrastingColor: CupertinoColors.destructiveRed,
+          ),
+        ));
+
+        expect(buildCount, 2);
+        expect(theme.textTheme.actionTextStyle.color, Colors.green);
+        expect(theme.primaryContrastingColor, CupertinoColors.destructiveRed);
+      },
+    );
+
+    testWidgets(
+      'copyWith only copies the overrides, not the material or cupertino derivatives',
+      (WidgetTester tester) async {
+        final CupertinoThemeData originalTheme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.purple,
+          cupertinoOverrideTheme: const CupertinoThemeData(
+            primaryContrastingColor: CupertinoColors.activeOrange,
+          ),
+        ));
+
+        final CupertinoThemeData copiedTheme = originalTheme.copyWith(
+          barBackgroundColor: CupertinoColors.destructiveRed,
+        );
+
+        final CupertinoThemeData theme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.blue,
+          cupertinoOverrideTheme: copiedTheme,
+        ));
+
+        expect(theme.primaryColor, Colors.blue);
+        expect(theme.primaryContrastingColor, CupertinoColors.activeOrange);
+        expect(theme.barBackgroundColor, CupertinoColors.destructiveRed);
+      },
+    );
+
+    testWidgets(
+      "Material themes with no cupertino overrides can also be copyWith'ed",
+      (WidgetTester tester) async {
+        final CupertinoThemeData originalTheme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.purple,
+        ));
+
+        final CupertinoThemeData copiedTheme = originalTheme.copyWith(
+          primaryContrastingColor: CupertinoColors.destructiveRed,
+        );
+
+        final CupertinoThemeData theme = await testTheme(tester, ThemeData(
+          primarySwatch: Colors.blue,
+          cupertinoOverrideTheme: copiedTheme,
+        ));
+
+        expect(theme.primaryColor, Colors.blue);
+        expect(theme.primaryContrastingColor, CupertinoColors.destructiveRed);
+      },
+    );
+  });
 }
 
 int testBuildCalled;

packages/flutter/test/widgets/inherited_model_test.dart

@@ -190,6 +190,22 @@ void main() {
     expect(find.text('a: 2 b: 2 c: 3'), findsOneWidget);
   });
 
+  testWidgets('Looking up an non existent InherintedModel ancestor returns null', (WidgetTester tester) async {
+    ABCModel inheritedModel;
+
+    await tester.pumpWidget(
+      Builder(
+        builder: (BuildContext context) {
+          inheritedModel = InheritedModel.inheritFrom(context);
+          return Container();
+        },
+      ),
+    );
+    // Shouldn't crash first of all.
+
+    expect(inheritedModel, null);
+  });
+
   testWidgets('Inner InheritedModel shadows the outer one', (WidgetTester tester) async {
     int _a = 0;
     int _b = 1;