Update accessibleNavigation when the state of accessibility changes (flutter/engine#33576)

engine/src/flutter/lib/web_ui/lib/platform_dispatcher.dart

@@ -120,7 +120,7 @@ abstract class PlatformDispatcher {
 
 class PlatformConfiguration {
   const PlatformConfiguration({
-    this.accessibilityFeatures = const AccessibilityFeatures._(0),
+    this.accessibilityFeatures = const engine.EngineAccessibilityFeatures(0),
     this.alwaysUse24HourFormat = false,
     this.semanticsEnabled = false,
     this.platformBrightness = Brightness.light,

engine/src/flutter/lib/web_ui/lib/src/engine/platform_dispatcher.dart

@@ -54,8 +54,7 @@ class EnginePlatformDispatcher extends ui.PlatformDispatcher {
 
   /// The current platform configuration.
   @override
-  ui.PlatformConfiguration get configuration => _configuration;
-  ui.PlatformConfiguration _configuration = ui.PlatformConfiguration(
+  ui.PlatformConfiguration configuration = ui.PlatformConfiguration(
     locales: parseBrowserLanguages(),
     textScaleFactor: findBrowserTextScaleFactor(),
   );
@@ -725,12 +724,12 @@ class EnginePlatformDispatcher extends ui.PlatformDispatcher {
   /// The empty list is not a valid value for locales. This is only used for
   /// testing locale update logic.
   void debugResetLocales() {
-    _configuration = _configuration.copyWith(locales: const <ui.Locale>[]);
+    configuration = configuration.copyWith(locales: const <ui.Locale>[]);
   }
 
   // Called by FlutterViewEmbedder when browser languages change.
   void updateLocales() {
-    _configuration = _configuration.copyWith(locales: parseBrowserLanguages());
+    configuration = configuration.copyWith(locales: parseBrowserLanguages());
   }
 
   static List<ui.Locale> parseBrowserLanguages() {
@@ -788,7 +787,7 @@ class EnginePlatformDispatcher extends ui.PlatformDispatcher {
   /// [onPlatformConfigurationChanged] callbacks if [textScaleFactor] changed.
   void _updateTextScaleFactor(double value) {
     if (configuration.textScaleFactor != value) {
-      _configuration = configuration.copyWith(textScaleFactor: value);
+      configuration = configuration.copyWith(textScaleFactor: value);
       invokeOnPlatformConfigurationChanged();
       invokeOnTextScaleFactorChanged();
     }
@@ -859,7 +858,7 @@ class EnginePlatformDispatcher extends ui.PlatformDispatcher {
 
   void updateSemanticsEnabled(bool semanticsEnabled) {
     if (semanticsEnabled != this.semanticsEnabled) {
-      _configuration = _configuration.copyWith(semanticsEnabled: semanticsEnabled);
+      configuration = configuration.copyWith(semanticsEnabled: semanticsEnabled);
       if (_onSemanticsEnabledChanged != null) {
         invokeOnSemanticsEnabledChanged();
       }
@@ -875,7 +874,7 @@ class EnginePlatformDispatcher extends ui.PlatformDispatcher {
   /// callback if [_platformBrightness] changed.
   void _updatePlatformBrightness(ui.Brightness value) {
     if (configuration.platformBrightness != value) {
-      _configuration = configuration.copyWith(platformBrightness: value);
+      configuration = configuration.copyWith(platformBrightness: value);
       invokeOnPlatformConfigurationChanged();
       invokeOnPlatformBrightnessChanged();
     }

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

@@ -26,6 +26,108 @@ import 'semantics_helper.dart';
 import 'tappable.dart';
 import 'text_field.dart';
 
+class EngineAccessibilityFeatures implements ui.AccessibilityFeatures {
+  const EngineAccessibilityFeatures(this._index);
+
+  static const int _kAccessibleNavigation = 1 << 0;
+  static const int _kInvertColorsIndex = 1 << 1;
+  static const int _kDisableAnimationsIndex = 1 << 2;
+  static const int _kBoldTextIndex = 1 << 3;
+  static const int _kReduceMotionIndex = 1 << 4;
+  static const int _kHighContrastIndex = 1 << 5;
+  static const int _kOnOffSwitchLabelsIndex = 1 << 6;
+
+  // A bitfield which represents each enabled feature.
+  final int _index;
+
+  @override
+  bool get accessibleNavigation => _kAccessibleNavigation & _index != 0;
+  @override
+  bool get invertColors => _kInvertColorsIndex & _index != 0;
+  @override
+  bool get disableAnimations => _kDisableAnimationsIndex & _index != 0;
+  @override
+  bool get boldText => _kBoldTextIndex & _index != 0;
+  @override
+  bool get reduceMotion => _kReduceMotionIndex & _index != 0;
+  @override
+  bool get highContrast => _kHighContrastIndex & _index != 0;
+  @override
+  bool get onOffSwitchLabels => _kOnOffSwitchLabelsIndex & _index != 0;
+
+  @override
+  String toString() {
+    final List<String> features = <String>[];
+    if (accessibleNavigation) {
+      features.add('accessibleNavigation');
+    }
+    if (invertColors) {
+      features.add('invertColors');
+    }
+    if (disableAnimations) {
+      features.add('disableAnimations');
+    }
+    if (boldText) {
+      features.add('boldText');
+    }
+    if (reduceMotion) {
+      features.add('reduceMotion');
+    }
+    if (highContrast) {
+      features.add('highContrast');
+    }
+    if (onOffSwitchLabels) {
+      features.add('onOffSwitchLabels');
+    }
+    return 'AccessibilityFeatures$features';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) {
+      return false;
+    }
+    return other is EngineAccessibilityFeatures && other._index == _index;
+  }
+
+  @override
+  int get hashCode => _index.hashCode;
+
+  EngineAccessibilityFeatures copyWith({
+      bool? accessibleNavigation,
+      bool? invertColors,
+      bool? disableAnimations,
+      bool? boldText,
+      bool? reduceMotion,
+      bool? highContrast,
+      bool? onOffSwitchLabels})
+  {
+    int value = 0;
+    if (accessibleNavigation ?? this.accessibleNavigation) {
+      value = value | _kAccessibleNavigation;
+    }
+    if (invertColors ?? this.invertColors) {
+      value = value | _kInvertColorsIndex;
+    }
+    if (disableAnimations ?? this.disableAnimations) {
+      value = value | _kDisableAnimationsIndex;
+    }
+    if (boldText ?? this.boldText) {
+      value = value | _kBoldTextIndex;
+    }
+    if (reduceMotion ?? this.reduceMotion) {
+      value = value | _kReduceMotionIndex;
+    }
+    if (highContrast ?? this.highContrast) {
+      value = value | _kHighContrastIndex;
+    }
+    if (onOffSwitchLabels ?? this.onOffSwitchLabels) {
+      value = value | _kOnOffSwitchLabelsIndex;
+    }
+    return EngineAccessibilityFeatures(value);
+  }
+}
+
 /// Contains updates for the semantics tree.
 ///
 /// This class provides private engine-side API that's not available in the
@@ -1433,6 +1535,15 @@ class EngineSemanticsOwner {
     if (value == _semanticsEnabled) {
       return;
     }
+    final EngineAccessibilityFeatures original =
+        EnginePlatformDispatcher.instance.configuration.accessibilityFeatures
+        as EngineAccessibilityFeatures;
+    final ui.PlatformConfiguration newConfiguration =
+        EnginePlatformDispatcher.instance.configuration.copyWith(
+            accessibilityFeatures:
+                original.copyWith(accessibleNavigation: value));
+    EnginePlatformDispatcher.instance.configuration = newConfiguration;
+
     _semanticsEnabled = value;
 
     if (!_semanticsEnabled) {

engine/src/flutter/lib/web_ui/lib/window.dart

@@ -148,66 +148,14 @@ abstract class SingletonFlutterWindow extends FlutterWindow {
   void setIsolateDebugName(String name) => PlatformDispatcher.instance.setIsolateDebugName(name);
 }
 
-class AccessibilityFeatures {
-  const AccessibilityFeatures._(this._index);
-
-  static const int _kAccessibleNavigation = 1 << 0;
-  static const int _kInvertColorsIndex = 1 << 1;
-  static const int _kDisableAnimationsIndex = 1 << 2;
-  static const int _kBoldTextIndex = 1 << 3;
-  static const int _kReduceMotionIndex = 1 << 4;
-  static const int _kHighContrastIndex = 1 << 5;
-  static const int _kOnOffSwitchLabelsIndex = 1 << 6;
-
-  // A bitfield which represents each enabled feature.
-  final int _index;
-
-  bool get accessibleNavigation => _kAccessibleNavigation & _index != 0;
-  bool get invertColors => _kInvertColorsIndex & _index != 0;
-  bool get disableAnimations => _kDisableAnimationsIndex & _index != 0;
-  bool get boldText => _kBoldTextIndex & _index != 0;
-  bool get reduceMotion => _kReduceMotionIndex & _index != 0;
-  bool get highContrast => _kHighContrastIndex & _index != 0;
-  bool get onOffSwitchLabels => _kOnOffSwitchLabelsIndex & _index != 0;
-
-  @override
-  String toString() {
-    final List<String> features = <String>[];
-    if (accessibleNavigation) {
-      features.add('accessibleNavigation');
-    }
-    if (invertColors) {
-      features.add('invertColors');
-    }
-    if (disableAnimations) {
-      features.add('disableAnimations');
-    }
-    if (boldText) {
-      features.add('boldText');
-    }
-    if (reduceMotion) {
-      features.add('reduceMotion');
-    }
-    if (highContrast) {
-      features.add('highContrast');
-    }
-    if (onOffSwitchLabels) {
-      features.add('onOffSwitchLabels');
-    }
-    return 'AccessibilityFeatures$features';
-  }
-
-  @override
-  bool operator ==(Object other) {
-    if (other.runtimeType != runtimeType) {
-      return false;
-    }
-    return other is AccessibilityFeatures
-        && other._index == _index;
-  }
-
-  @override
-  int get hashCode => _index.hashCode;
+abstract class AccessibilityFeatures {
+  bool get accessibleNavigation;
+  bool get invertColors;
+  bool get disableAnimations;
+  bool get boldText;
+  bool get reduceMotion;
+  bool get highContrast;
+  bool get onOffSwitchLabels;
 }
 
 enum Brightness {

engine/src/flutter/lib/web_ui/test/engine/semantics/semantics_test.dart

@@ -118,9 +118,79 @@ void _testEngineSemanticsOwner() {
     expect(placeholder.isConnected, isFalse);
   });
 
+  test('accessibilityFeatures copyWith function works', () {
+    const EngineAccessibilityFeatures original = EngineAccessibilityFeatures(0);
+    EngineAccessibilityFeatures copy = original.copyWith(accessibleNavigation: true);
+    expect(copy.accessibleNavigation, true);
+    expect(copy.boldText, false);
+    expect(copy.disableAnimations, false);
+    expect(copy.highContrast, false);
+    expect(copy.invertColors, false);
+    expect(copy.onOffSwitchLabels, false);
+    expect(copy.reduceMotion, false);
+
+    copy = original.copyWith(boldText: true);
+    expect(copy.accessibleNavigation, false);
+    expect(copy.boldText, true);
+    expect(copy.disableAnimations, false);
+    expect(copy.highContrast, false);
+    expect(copy.invertColors, false);
+    expect(copy.onOffSwitchLabels, false);
+    expect(copy.reduceMotion, false);
+
+    copy = original.copyWith(disableAnimations: true);
+    expect(copy.accessibleNavigation, false);
+    expect(copy.boldText, false);
+    expect(copy.disableAnimations, true);
+    expect(copy.highContrast, false);
+    expect(copy.invertColors, false);
+    expect(copy.onOffSwitchLabels, false);
+    expect(copy.reduceMotion, false);
+
+    copy = original.copyWith(highContrast: true);
+    expect(copy.accessibleNavigation, false);
+    expect(copy.boldText, false);
+    expect(copy.disableAnimations, false);
+    expect(copy.highContrast, true);
+    expect(copy.invertColors, false);
+    expect(copy.onOffSwitchLabels, false);
+    expect(copy.reduceMotion, false);
+
+    copy = original.copyWith(invertColors: true);
+    expect(copy.accessibleNavigation, false);
+    expect(copy.boldText, false);
+    expect(copy.disableAnimations, false);
+    expect(copy.highContrast, false);
+    expect(copy.invertColors, true);
+    expect(copy.onOffSwitchLabels, false);
+    expect(copy.reduceMotion, false);
+
+    copy = original.copyWith(onOffSwitchLabels: true);
+    expect(copy.accessibleNavigation, false);
+    expect(copy.boldText, false);
+    expect(copy.disableAnimations, false);
+    expect(copy.highContrast, false);
+    expect(copy.invertColors, false);
+    expect(copy.onOffSwitchLabels, true);
+    expect(copy.reduceMotion, false);
+
+    copy = original.copyWith(reduceMotion: true);
+    expect(copy.accessibleNavigation, false);
+    expect(copy.boldText, false);
+    expect(copy.disableAnimations, false);
+    expect(copy.highContrast, false);
+    expect(copy.invertColors, false);
+    expect(copy.onOffSwitchLabels, false);
+    expect(copy.reduceMotion, true);
+  });
+
   test('auto-enables semantics', () async {
     flutterViewEmbedder.reset(); // triggers `autoEnableOnTap` to be called
     expect(semantics().semanticsEnabled, isFalse);
+    expect(
+        EnginePlatformDispatcher
+            .instance.configuration.accessibilityFeatures.accessibleNavigation,
+        isFalse);
 
     final html.Element placeholder =
         appHostNode.querySelector('flt-semantics-placeholder')!;
@@ -133,6 +203,10 @@ void _testEngineSemanticsOwner() {
     semantics().updateSemantics(builder.build());
 
     expect(semantics().semanticsEnabled, isTrue);
+    expect(
+        EnginePlatformDispatcher
+            .instance.configuration.accessibilityFeatures.accessibleNavigation,
+        isTrue);
 
     // The placeholder should be removed
     expect(placeholder.isConnected, isFalse);
@@ -1753,6 +1827,7 @@ void _testPlatformView() {
       rect: const ui.Rect.fromLTRB(0, 0, 20, 60),
       childrenInTraversalOrder: Int32List.fromList(<int>[1, 2, 3]),
       childrenInHitTestOrder: Int32List.fromList(<int>[1, 2, 3]),
+      transform: Float64List.fromList(Matrix4.diagonal3Values(ui.window.devicePixelRatio, ui.window.devicePixelRatio, 1).storage)
     );
     updateNode(
       builder,