Added InheritedTheme (#38583)

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

@@ -116,7 +116,7 @@ class MaterialBannerThemeData extends Diagnosticable {
 ///
 /// Values specified here are used for [MaterialBanner] properties that are not
 /// given an explicit non-null value.
-class MaterialBannerTheme extends InheritedWidget {
+class MaterialBannerTheme extends InheritedTheme {
   /// Creates a banner theme that controls the configurations for
   /// [MaterialBanner]s in its widget subtree.
   const MaterialBannerTheme({
@@ -144,6 +144,12 @@ class MaterialBannerTheme extends InheritedWidget {
     return popupMenuTheme?.data ?? Theme.of(context).bannerTheme;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final MaterialBannerTheme ancestorTheme = context.ancestorWidgetOfExactType(MaterialBannerTheme);
+    return identical(this, ancestorTheme) ? child : MaterialBannerTheme(data: data, child: child);
+  }
+
   @override
   bool updateShouldNotify(MaterialBannerTheme oldWidget) => data != oldWidget.data;
 }

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

@@ -63,7 +63,7 @@ enum ButtonBarLayoutBehavior {
 ///    based on the ambient button theme.
 ///  * [RawMaterialButton], which can be used to configure a button that doesn't
 ///    depend on any inherited themes.
-class ButtonTheme extends InheritedWidget {
+class ButtonTheme extends InheritedTheme {
   /// Creates a button theme.
   ///
   /// The [textTheme], [minWidth], [height], and [colorScheme] arguments
@@ -230,6 +230,12 @@ class ButtonTheme extends InheritedWidget {
     return buttonTheme;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final ButtonTheme ancestorTheme = context.ancestorWidgetOfExactType(ButtonTheme);
+    return identical(this, ancestorTheme) ? child : ButtonTheme.fromButtonThemeData(data: data, child: child);
+  }
+
   @override
   bool updateShouldNotify(ButtonTheme oldWidget) => data != oldWidget.data;
 }

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

@@ -40,7 +40,7 @@ import 'theme_data.dart';
 ///    theme.
 ///  * [ThemeData], which describes the overall theme information for the
 ///    application.
-class ChipTheme extends InheritedWidget {
+class ChipTheme extends InheritedTheme {
   /// Applies the given theme [data] to [child].
   ///
   /// The [data] and [child] arguments must not be null.
@@ -89,6 +89,12 @@ class ChipTheme extends InheritedWidget {
     return inheritedTheme?.data ?? Theme.of(context).chipTheme;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final ChipTheme ancestorTheme = context.ancestorWidgetOfExactType(ChipTheme);
+    return identical(this, ancestorTheme) ? child : ChipTheme(data: data, child: child);
+  }
+
   @override
   bool updateShouldNotify(ChipTheme oldWidget) => data != oldWidget.data;
 }

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

@@ -132,7 +132,7 @@ class DividerThemeData extends Diagnosticable {
 /// An inherited widget that defines the configuration for
 /// [Divider]s, [VerticalDividers]s, dividers between [ListTile]s, and dividers
 /// between rows in [DataTable]s in this widget's subtree.
-class DividerTheme extends InheritedWidget {
+class DividerTheme extends InheritedTheme {
   /// Creates a divider theme that controls the configurations for
   /// [Divider]s, [VerticalDividers]s, dividers between [ListTile]s, and dividers
   /// between rows in [DataTable]s in its widget subtree.
@@ -163,6 +163,12 @@ class DividerTheme extends InheritedWidget {
     return dividerTheme?.data ?? Theme.of(context).dividerTheme;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final DividerTheme ancestorTheme = context.ancestorWidgetOfExactType(DividerTheme);
+    return identical(this, ancestorTheme) ? child : DividerTheme(data: data, child: child);
+  }
+
   @override
   bool updateShouldNotify(DividerTheme oldWidget) => data != oldWidget.data;
 }

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

@@ -36,7 +36,7 @@ enum ListTileStyle {
 ///
 /// The [Drawer] widget specifies a tile theme for its children which sets
 /// [style] to [ListTileStyle.drawer].
-class ListTileTheme extends InheritedWidget {
+class ListTileTheme extends InheritedTheme {
   /// Creates a list tile theme that controls the color and style parameters for
   /// [ListTile]s.
   const ListTileTheme({
@@ -115,6 +115,20 @@ class ListTileTheme extends InheritedWidget {
     return result ?? const ListTileTheme();
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final ListTileTheme ancestorTheme = context.ancestorWidgetOfExactType(ListTileTheme);
+    return identical(this, ancestorTheme) ? child : ListTileTheme(
+      dense: dense,
+      style: style,
+      selectedColor: selectedColor,
+      iconColor: iconColor,
+      textColor: textColor,
+      contentPadding: contentPadding,
+      child: child,
+    );
+  }
+
   @override
   bool updateShouldNotify(ListTileTheme oldWidget) {
     return dense != oldWidget.dense

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

@@ -264,7 +264,7 @@ class PopupMenuItemState<T, W extends PopupMenuItem<T>> extends State<W> {
       duration: kThemeChangeDuration,
       child: Baseline(
         baseline: widget.height - _kBaselineOffsetFromBottom,
-        baselineType: style.textBaseline,
+        baselineType: style.textBaseline ?? TextBaseline.alphabetic,
         child: buildChild(),
       ),
     );
@@ -608,6 +608,8 @@ class _PopupMenuRoute<T> extends PopupRoute<T> {
     this.semanticLabel,
     this.shape,
     this.color,
+    this.showMenuContext,
+    this.captureInheritedThemes,
   });
 
   final RelativeRect position;
@@ -619,6 +621,8 @@ class _PopupMenuRoute<T> extends PopupRoute<T> {
   final ShapeBorder shape;
   final Color color;
   final PopupMenuThemeData popupMenuTheme;
+  final BuildContext showMenuContext;
+  final bool captureInheritedThemes;
 
   @override
   Animation<double> createAnimation() {
@@ -656,10 +660,15 @@ class _PopupMenuRoute<T> extends PopupRoute<T> {
     }
 
     Widget menu = _PopupMenu<T>(route: this, semanticLabel: semanticLabel);
-    if (popupMenuTheme != null)
-      menu = PopupMenuTheme(data: PopupMenuThemeData(textStyle: popupMenuTheme.textStyle), child: menu);
-    if (theme != null)
-      menu = Theme(data: theme, child: menu);
+    if (captureInheritedThemes) {
+      menu = InheritedTheme.captureAll(showMenuContext, menu);
+    } else {
+      // For the sake of backwards compatibility. An (unlikely) app that relied
+      // on having menus only inherit from the material Theme could set
+      // captureInheritedThemes to false and get the original behvaior.
+      if (theme != null)
+        menu = Theme(data: theme, child: menu);
+    }
 
     return MediaQuery.removePadding(
       context: context,
@@ -743,10 +752,12 @@ Future<T> showMenu<T>({
   String semanticLabel,
   ShapeBorder shape,
   Color color,
+  bool captureInheritedThemes = true,
 }) {
   assert(context != null);
   assert(position != null);
   assert(items != null && items.isNotEmpty);
+  assert(captureInheritedThemes != null);
   assert(debugCheckHasMaterialLocalizations(context));
 
   String label = semanticLabel;
@@ -770,6 +781,8 @@ Future<T> showMenu<T>({
     barrierLabel: MaterialLocalizations.of(context).modalBarrierDismissLabel,
     shape: shape,
     color: color,
+    showMenuContext: context,
+    captureInheritedThemes: captureInheritedThemes,
   ));
 }
 
@@ -862,9 +875,11 @@ class PopupMenuButton<T> extends StatefulWidget {
     this.enabled = true,
     this.shape,
     this.color,
+    this.captureInheritedThemes = true,
   }) : assert(itemBuilder != null),
        assert(offset != null),
        assert(enabled != null),
+       assert(captureInheritedThemes != null),
        assert(!(child != null && icon != null)), // fails if passed both parameters
        super(key: key);
 
@@ -943,6 +958,11 @@ class PopupMenuButton<T> extends StatefulWidget {
   /// Theme.of(context).cardColor is used.
   final Color color;
 
+  /// If true (the default) then the menu will be wrapped with copies
+  /// of the [InheritedThemes], like [Theme] and [PopupMenuTheme], which
+  /// are defined above the [BuildContext] where the menu is shown.
+  final bool captureInheritedThemes;
+
   @override
   _PopupMenuButtonState<T> createState() => _PopupMenuButtonState<T>();
 }
@@ -970,6 +990,7 @@ class _PopupMenuButtonState<T> extends State<PopupMenuButton<T>> {
         position: position,
         shape: widget.shape ?? popupMenuTheme.shape,
         color: widget.color ?? popupMenuTheme.color,
+        captureInheritedThemes: widget.captureInheritedThemes,
       )
       .then<void>((T newValue) {
         if (!mounted)

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

@@ -121,7 +121,7 @@ class PopupMenuThemeData extends Diagnosticable {
 ///
 /// Values specified here are used for popup menu properties that are not
 /// given an explicit non-null value.
-class PopupMenuTheme extends InheritedWidget {
+class PopupMenuTheme extends InheritedTheme {
   /// Creates a popup menu theme that controls the configurations for
   /// popup menus in its widget subtree.
   ///
@@ -149,6 +149,12 @@ class PopupMenuTheme extends InheritedWidget {
     return popupMenuTheme?.data ?? Theme.of(context).popupMenuTheme;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final PopupMenuTheme ancestorTheme = context.ancestorWidgetOfExactType(PopupMenuTheme);
+    return identical(this, ancestorTheme) ? child : PopupMenuTheme(data: data, child: child);
+  }
+
   @override
   bool updateShouldNotify(PopupMenuTheme oldWidget) => data != oldWidget.data;
 }

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

@@ -134,7 +134,7 @@ import 'theme_data.dart';
 /// {@macro flutter.material.slider.seeAlso.rangeSliderValueIndicatorShape}
 /// {@macro flutter.material.slider.seeAlso.rangeSliderTrackShape}
 /// {@macro flutter.material.slider.seeAlso.rangeSliderTickMarkShape}
-class SliderTheme extends InheritedWidget {
+class SliderTheme extends InheritedTheme {
   /// Applies the given theme [data] to [child].
   ///
   /// The [data] and [child] arguments must not be null.
@@ -189,6 +189,12 @@ class SliderTheme extends InheritedWidget {
     return inheritedTheme != null ? inheritedTheme.data : Theme.of(context).sliderTheme;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final SliderTheme ancestorTheme = context.ancestorWidgetOfExactType(SliderTheme);
+    return identical(this, ancestorTheme) ? child : SliderTheme(data: data, child: child);
+  }
+
   @override
   bool updateShouldNotify(SliderTheme oldWidget) => data != oldWidget.data;
 }
@@ -2928,4 +2934,3 @@ class RangeLabels {
     return '$runtimeType($start, $end)';
   }
 }
-

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

@@ -164,7 +164,7 @@ class Theme extends StatelessWidget {
   }
 }
 
-class _InheritedTheme extends InheritedWidget {
+class _InheritedTheme extends InheritedTheme {
   const _InheritedTheme({
     Key key,
     @required this.theme,
@@ -174,6 +174,12 @@ class _InheritedTheme extends InheritedWidget {
 
   final Theme theme;
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final _InheritedTheme ancestorTheme = context.ancestorWidgetOfExactType(_InheritedTheme);
+    return identical(this, ancestorTheme) ? child : Theme(data: theme.data, child: child);
+  }
+
   @override
   bool updateShouldNotify(_InheritedTheme old) => theme.data != old.theme.data;
 }

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

@@ -227,7 +227,7 @@ class ToggleButtonsThemeData extends Diagnosticable {
 ///
 /// Values specified here are used for [ToggleButtons] properties that are not
 /// given an explicit non-null value.
-class ToggleButtonsTheme extends InheritedWidget {
+class ToggleButtonsTheme extends InheritedTheme {
   /// Creates a toggle buttons theme that controls the color and border
   /// parameters for [ToggleButtons].
   ///
@@ -256,6 +256,12 @@ class ToggleButtonsTheme extends InheritedWidget {
     return toggleButtonsTheme?.data ?? Theme.of(context).toggleButtonsTheme;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final ToggleButtonsTheme ancestorTheme = context.ancestorWidgetOfExactType(ToggleButtonsTheme);
+    return identical(this, ancestorTheme) ? child : ToggleButtonsTheme(data: data, child: child);
+  }
+
   @override
   bool updateShouldNotify(ToggleButtonsTheme oldWidget) => data != oldWidget.data;
 }

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

@@ -213,7 +213,7 @@ class TooltipThemeData extends Diagnosticable {
 /// ),
 /// ```
 /// {@end-tool}
-class TooltipTheme extends InheritedWidget {
+class TooltipTheme extends InheritedTheme {
   /// Creates a tooltip theme that controls the configurations for
   /// [Tooltip].
   ///
@@ -241,6 +241,12 @@ class TooltipTheme extends InheritedWidget {
     return tooltipTheme?.data ?? Theme.of(context).tooltipTheme;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final TooltipTheme ancestorTheme = context.ancestorWidgetOfExactType(TooltipTheme);
+    return identical(this, ancestorTheme) ? child : TooltipTheme(data: data, child: child);
+  }
+
   @override
   bool updateShouldNotify(TooltipTheme oldWidget) => data != oldWidget.data;
 }

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

@@ -7,11 +7,12 @@ import 'package:flutter/foundation.dart';
 import 'basic.dart';
 import 'framework.dart';
 import 'icon_theme_data.dart';
+import 'inherited_theme.dart';
 
 /// Controls the default color, opacity, and size of icons in a widget subtree.
 ///
 /// The icon theme is honored by [Icon] and [ImageIcon] widgets.
-class IconTheme extends InheritedWidget {
+class IconTheme extends InheritedTheme {
   /// Creates an icon theme that controls the color, opacity, and size of
   /// descendant widgets.
   ///
@@ -70,6 +71,12 @@ class IconTheme extends InheritedWidget {
   @override
   bool updateShouldNotify(IconTheme oldWidget) => data != oldWidget.data;
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final IconTheme iconTheme = context.ancestorWidgetOfExactType(IconTheme);
+    return identical(this, iconTheme) ? child : IconTheme(data: data, child: child);
+  }
+
   @override
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);

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

+// Copyright 2019 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 'framework.dart';
+
+/// An [InheritedWidget] that defines visual properties like colors
+/// and text styles, which the [child]'s subtree depends on.
+///
+/// The [wrap] method is used by [captureAll] to construct a widget
+/// that will wrap a child in all of the inherited themes which
+/// are present in a build context but are not present in the
+/// context that the returned widget is eventually built in.
+///
+/// A widget that's shown in a different context from the one it's
+/// built in, like the contents of a new route or an overlay, will
+/// be able to depend on inherited widget ancestors of the context
+/// it's built in.
+///
+/// {@tool snippet --template=freeform}
+/// This example demonstrates how `InheritedTheme.captureAll()` can be used
+/// to wrap the contents of a new route with the inherited themes that
+/// are present when the route is built - but are not present when route
+/// is actually shown.
+///
+/// If the same code is run without `InheritedTheme.captureAll(), the
+/// new route's Text widget will inherit the "something must be wrong"
+/// fallback text style, rather than the default text style defined in MyApp.
+///
+/// ```dart imports
+/// import 'package:flutter/material.dart';
+/// ```
+///
+/// ```dart main
+/// void main() {
+///   runApp(MyApp());
+/// }
+/// ```
+///
+/// ```dart
+/// class MyAppBody extends StatelessWidget {
+///   @override
+///   Widget build(BuildContext context) {
+///     return GestureDetector(
+///       onTap: () {
+///         Navigator.of(context).push(
+///           MaterialPageRoute(
+///             builder: (BuildContext _) {
+///               // InheritedTheme.captureAll() saves references to themes that
+///               // are found above the context provided to this widget's build
+///               // method, notably the DefaultTextStyle defined in MyApp. The
+///               // context passed to the MaterialPageRoute's builder is not used,
+///               // because its ancestors are above MyApp's home.
+///               return InheritedTheme.captureAll(context, Container(
+///                 alignment: Alignment.center,
+///                 color: Theme.of(context).colorScheme.surface,
+///                 child: Text('Hello World'),
+///               ));
+///             },
+///           ),
+///         );
+///       },
+///       child: Center(child: Text('Tap Here')),
+///     );
+///   }
+/// }
+///
+/// class MyApp extends StatelessWidget {
+///   @override
+///   Widget build(BuildContext context) {
+///     return MaterialApp(
+///       home: Scaffold(
+///         // Override the DefaultTextStyle defined by the Scaffold.
+///         // Descendant widgets will inherit this big blue text style.
+///         body: DefaultTextStyle(
+///           style: TextStyle(fontSize: 48, color: Colors.blue),
+///           child: MyAppBody(),
+///         ),
+///       ),
+///     );
+///   }
+/// }
+/// ```
+/// {@end-tool}
+abstract class InheritedTheme extends InheritedWidget {
+  /// Abstract const constructor. This constructor enables subclasses to provide
+  /// const constructors so that they can be used in const expressions.
+
+  const InheritedTheme({
+    Key key,
+    @required Widget child,
+  }) : super(key: key, child: child);
+
+  /// Return a copy of this inherited theme with the specified [child].
+  ///
+  /// If the identical inherited theme is already visible from [context] then
+  /// just return the [child].
+  ///
+  /// This implementation for [TooltipTheme] is typical:
+  /// ```dart
+  /// Widget wrap(BuildContext context, Widget child) {
+  ///   final TooltipTheme ancestorTheme = context.ancestorWidgetOfExactType(TooltipTheme);
+  ///   return identical(this, ancestorTheme) ? child : TooltipTheme(data: data, child: child);
+  /// }
+  /// ```
+  Widget wrap(BuildContext context, Widget child);
+
+  /// Returns a widget that will [wrap] child in all of the inherited themes
+  /// which are visible from [context].
+  static Widget captureAll(BuildContext context, Widget child) {
+    assert(child != null);
+    assert(context != null);
+
+    final List<InheritedTheme> themes = <InheritedTheme>[];
+    context.visitAncestorElements((Element ancestor) {
+      if (ancestor is InheritedElement && ancestor.widget is InheritedTheme) {
+        final InheritedTheme theme = ancestor.widget;
+        themes.add(theme);
+      }
+      return true;
+    });
+
+    return _CaptureAll(themes: themes, child: child);
+  }
+}
+
+class _CaptureAll extends StatelessWidget {
+  const _CaptureAll({
+    Key key,
+    @required this.themes,
+    @required this.child
+  }) : assert(themes != null), assert(child != null), super(key: key);
+
+  final List<InheritedTheme> themes;
+  final Widget child;
+
+  @override
+  Widget build(BuildContext context) {
+    Widget wrappedChild = child;
+    for (InheritedTheme theme in themes)
+      wrappedChild = theme.wrap(context, wrappedChild);
+    return wrappedChild;
+  }
+}

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

@@ -7,6 +7,7 @@ import 'package:flutter/painting.dart';
 
 import 'basic.dart';
 import 'framework.dart';
+import 'inherited_theme.dart';
 import 'media_query.dart';
 
 // Examples can assume:
@@ -20,7 +21,7 @@ import 'media_query.dart';
 ///    smoothly over a given duration.
 ///  * [DefaultTextStyleTransition], which takes a provided [Animation] to
 ///    animate changes in text style smoothly over time.
-class DefaultTextStyle extends InheritedWidget {
+class DefaultTextStyle extends InheritedTheme {
   /// Creates a default text style for the given subtree.
   ///
   /// Consider using [DefaultTextStyle.merge] to inherit styling information
@@ -161,6 +162,20 @@ class DefaultTextStyle extends InheritedWidget {
         textWidthBasis != oldWidget.textWidthBasis;
   }
 
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final DefaultTextStyle defaultTextStyle = context.ancestorWidgetOfExactType(DefaultTextStyle);
+    return identical(this, defaultTextStyle) ? child : DefaultTextStyle(
+      style: style,
+      textAlign: textAlign,
+      softWrap: softWrap,
+      overflow: overflow,
+      maxLines: maxLines,
+      textWidthBasis: textWidthBasis,
+      child: child,
+    );
+  }
+
   @override
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);

packages/flutter/lib/widgets.dart

@@ -52,6 +52,7 @@ export 'src/widgets/image_icon.dart';
 export 'src/widgets/implicit_animations.dart';
 export 'src/widgets/inherited_model.dart';
 export 'src/widgets/inherited_notifier.dart';
+export 'src/widgets/inherited_theme.dart';
 export 'src/widgets/layout_builder.dart';
 export 'src/widgets/list_wheel_scroll_view.dart';
 export 'src/widgets/localizations.dart';

packages/flutter/test/widgets/inherited_theme_test.dart

+// Copyright 2019 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/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+class TestRoute extends PageRouteBuilder<void> {
+  TestRoute(Widget child) : super(
+    pageBuilder: (BuildContext _, Animation<double> __, Animation<double> ___) => child,
+  );
+}
+
+class IconTextBox extends StatelessWidget {
+  const IconTextBox(this.text);
+  final String text;
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      alignment: Alignment.center,
+      child: Row(
+        children: <Widget>[const Icon(IconData(0x41, fontFamily: 'Roboto')), Text(text)],
+      ),
+    );
+  }
+}
+
+void main() {
+  testWidgets('InheritedTheme.captureAll()', (WidgetTester tester) async {
+    const double fontSize = 32;
+    const double iconSize = 48;
+    const Color textColor = Color(0xFF00FF00);
+    const Color iconColor = Color(0xFF0000FF);
+    bool useCaptureAll = false;
+    BuildContext navigatorContext;
+
+    Widget buildFrame() {
+      return WidgetsApp(
+        color: const Color(0xFFFFFFFF),
+        onGenerateRoute: (RouteSettings settings) {
+          return TestRoute(
+            // The outer DefaultTextStyle and IconTheme widgets must have
+            // no effect on the test because InheritedTheme.captureAll()
+            // is required to only save the closest InheritedTheme ancestors.
+            DefaultTextStyle(
+              style: const TextStyle(fontSize: iconSize, color: iconColor),
+              child: IconTheme(
+                data: const IconThemeData(size: fontSize, color: textColor),
+                // The inner DefaultTextStyle and IconTheme widgets define
+                // InheritedThemes that captureAll() will wrap() around
+                // TestRoute's IconTextBox child.
+                child: DefaultTextStyle(
+                  style: const TextStyle(fontSize: fontSize, color: textColor),
+                  child: IconTheme(
+                    data: const IconThemeData(size: iconSize, color: iconColor),
+                    child: Builder(
+                      builder: (BuildContext context) {
+                        return GestureDetector(
+                          behavior: HitTestBehavior.opaque,
+                          onTap: () {
+                            navigatorContext = context;
+                            Navigator.of(context).push(
+                              TestRoute(
+                                useCaptureAll
+                                  ? InheritedTheme.captureAll(context, const IconTextBox('Hello'))
+                                  : const IconTextBox('Hello')
+                              ),
+                            );
+                          },
+                          child: const IconTextBox('Tap'),
+                        );
+                      },
+                    ),
+                  ),
+                ),
+              ),
+            ),
+          );
+        },
+      );
+    }
+
+    TextStyle getIconStyle() {
+      return tester.widget<RichText>(
+        find.descendant(
+          of: find.byType(Icon),
+          matching: find.byType(RichText),
+        ),
+      ).text.style;
+    }
+
+    TextStyle getTextStyle(String text) {
+      return tester.widget<RichText>(
+        find.descendant(
+          of: find.text(text),
+          matching: find.byType(RichText),
+        ),
+      ).text.style;
+    }
+
+    useCaptureAll = false;
+    await tester.pumpWidget(buildFrame());
+    expect(find.text('Tap'), findsOneWidget);
+    expect(find.text('Hello'), findsNothing);
+    expect(getTextStyle('Tap').color, textColor);
+    expect(getTextStyle('Tap').fontSize, fontSize);
+    expect(getIconStyle().color, iconColor);
+    expect(getIconStyle().fontSize, iconSize);
+
+    // Tap to show the TestRoute
+    await tester.tap(find.text('Tap'));
+    await tester.pumpAndSettle(); // route transition
+    expect(find.text('Tap'), findsNothing);
+    expect(find.text('Hello'), findsOneWidget);
+    // The new route's text and icons will NOT inherit the DefaultTextStyle or
+    // IconTheme values.
+    expect(getTextStyle('Hello').color, isNot(textColor));
+    expect(getTextStyle('Hello').fontSize, isNot(fontSize));
+    expect(getIconStyle().color, isNot(iconColor));
+    expect(getIconStyle().fontSize, isNot(iconSize));
+
+    // Return to the home route
+    useCaptureAll = true;
+    Navigator.of(navigatorContext).pop();
+    await tester.pumpAndSettle(); // route transition
+
+    // Verify that all is the same as it was when the test started
+    expect(find.text('Tap'), findsOneWidget);
+    expect(find.text('Hello'), findsNothing);
+    expect(getTextStyle('Tap').color, textColor);
+    expect(getTextStyle('Tap').fontSize, fontSize);
+    expect(getIconStyle().color, iconColor);
+    expect(getIconStyle().fontSize, iconSize);
+
+    // Tap to show the TestRoute. The test route's IconTextBox will have been
+    // wrapped with InheritedTheme.captureAll().
+    await tester.tap(find.text('Tap'));
+    await tester.pumpAndSettle(); // route transition
+    expect(find.text('Tap'), findsNothing);
+    expect(find.text('Hello'), findsOneWidget);
+    // The new route's text and icons will inherit the DefaultTextStyle or
+    // IconTheme values because captureAll.
+    expect(getTextStyle('Hello').color, textColor);
+    expect(getTextStyle('Hello').fontSize, fontSize);
+    expect(getIconStyle().color, iconColor);
+    expect(getIconStyle().fontSize, iconSize);
+
+  });
+}