Rewire ios accessibility bridge receive semantics enabled signal

ci/licenses_golden/excluded_files

@@ -274,6 +274,7 @@
 ../../../flutter/runtime/fixtures
 ../../../flutter/runtime/no_dart_plugin_registrant_unittests.cc
 ../../../flutter/runtime/platform_isolate_manager_unittests.cc
+../../../flutter/runtime/runtime_controller_unittests.cc
 ../../../flutter/runtime/type_conversions_unittests.cc
 ../../../flutter/shell/common/animator_unittests.cc
 ../../../flutter/shell/common/base64_unittests.cc

ci/licenses_golden/licenses_flutter

@@ -44693,6 +44693,7 @@ ORIGIN: ../../../flutter/shell/platform/darwin/ios/platform_message_handler_ios.
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/platform_message_handler_ios_test.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/platform_view_ios.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/platform_view_ios.mm + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/shell/platform/darwin/ios/platform_view_ios_test.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/rendering_api_selection.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/rendering_api_selection.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppDelegate.h + ../../../flutter/LICENSE
@@ -47646,6 +47647,7 @@ FILE: ../../../flutter/shell/platform/darwin/ios/platform_message_handler_ios.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/platform_message_handler_ios_test.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/platform_view_ios.h
 FILE: ../../../flutter/shell/platform/darwin/ios/platform_view_ios.mm
+FILE: ../../../flutter/shell/platform/darwin/ios/platform_view_ios_test.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/rendering_api_selection.h
 FILE: ../../../flutter/shell/platform/darwin/ios/rendering_api_selection.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppDelegate.h

lib/ui/dart_ui.cc

@@ -99,6 +99,7 @@ typedef CanvasPath Path;
   V(PlatformConfigurationNativeApi::UpdateSemantics)               \
   V(PlatformConfigurationNativeApi::SetNeedsReportTimings)         \
   V(PlatformConfigurationNativeApi::SetIsolateDebugName)           \
+  V(PlatformConfigurationNativeApi::SetSemanticsTreeEnabled)       \
   V(PlatformConfigurationNativeApi::RequestDartPerformanceMode)    \
   V(PlatformConfigurationNativeApi::GetPersistentIsolateData)      \
   V(PlatformConfigurationNativeApi::ComputePlatformResolvedLocale) \

lib/ui/window.dart

@@ -382,9 +382,8 @@ class FlutterView {
 
   /// Change the retained semantics data about this [FlutterView].
   ///
-  /// If [PlatformDispatcher.semanticsEnabled] is true, the user has requested that this function
-  /// be called whenever the semantic content of this [FlutterView]
-  /// changes.
+  /// Th [setSemanticsTreeEnabled] must be called with true before sending
+  /// update through this method.
   ///
   /// This function disposes the given update, which means the semantics update
   /// cannot be used further.
@@ -393,6 +392,26 @@ class FlutterView {
   @Native<Void Function(Pointer<Void>)>(symbol: 'PlatformConfigurationNativeApi::UpdateSemantics')
   external static void _updateSemantics(_NativeSemanticsUpdate update);
 
+  /// Informs the engine whether the framework is generating a semantics tree.
+  ///
+  /// Only framework knows when semantics tree should be generated. It uses this
+  /// method to notify the engine such event.
+  ///
+  /// In the case where platforms want to enable semantics, e.g. when detected running
+  /// assitive technologies, it notifies framework through the
+  /// [PlatformDispatcher.onSemanticsEnabledChanged].
+  ///
+  /// After this has been set to true, platforms are expected to prepare for accepting
+  /// semantics update sent via [updateSemantics]. When this is set to false, platforms
+  /// may dispose any resources associated with processing semantics as no further
+  /// semantics updates will be sent via [updateSemantics].
+  ///
+  /// One must call this method with true before sending update through [updateSemantics].
+  void setSemanticsTreeEnabled(bool enabled) => _setSemanticsTreeEnabled(enabled);
+
+  @Native<Void Function(Bool)>(symbol: 'PlatformConfigurationNativeApi::SetSemanticsTreeEnabled')
+  external static void _setSemanticsTreeEnabled(bool update);
+
   @override
   String toString() => 'FlutterView(id: $viewId)';
 }

lib/ui/window/platform_configuration.cc

@@ -621,6 +621,14 @@ void PlatformConfigurationNativeApi::UpdateSemantics(SemanticsUpdate* update) {
       update);
 }
 
+void PlatformConfigurationNativeApi::SetSemanticsTreeEnabled(bool enabled) {
+  UIDartState::ThrowIfUIOperationsProhibited();
+  UIDartState::Current()
+      ->platform_configuration()
+      ->client()
+      ->SetSemanticsTreeEnabled(enabled);
+}
+
 Dart_Handle PlatformConfigurationNativeApi::ComputePlatformResolvedLocale(
     Dart_Handle supportedLocalesHandle) {
   UIDartState::ThrowIfUIOperationsProhibited();

lib/ui/window/platform_configuration.h

@@ -95,6 +95,13 @@ class PlatformConfigurationClient {
   ///
   virtual void UpdateSemantics(SemanticsUpdate* update) = 0;
 
+  //--------------------------------------------------------------------------
+  /// @brief      Notifies whether Framework starts generating semantics tree.
+  ///
+  /// @param[in] enabled True if Framework starts generating semantics tree.
+  ///
+  virtual void SetSemanticsTreeEnabled(bool enabled) = 0;
+
   //--------------------------------------------------------------------------
   /// @brief      When the Flutter application has a message to send to the
   ///             underlying platform, the message needs to be forwarded to
@@ -594,6 +601,8 @@ class PlatformConfigurationNativeApi {
 
   static void UpdateSemantics(SemanticsUpdate* update);
 
+  static void SetSemanticsTreeEnabled(bool enabled);
+
   static void SetNeedsReportTimings(bool value);
 
   static Dart_Handle GetPersistentIsolateData();

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

@@ -135,6 +135,14 @@ class EngineFlutterView implements ui.FlutterView {
     semantics.updateSemantics(update);
   }
 
+  @override
+  void setSemanticsTreeEnabled(bool enabled) {
+    assert(!isDisposed, 'Trying to update semantics on a disposed EngineFlutterView.');
+    if (!enabled) {
+      semantics.reset();
+    }
+  }
+
   late final GlobalHtmlAttributes _globalHtmlAttributes = GlobalHtmlAttributes(
     rootElement: dom.rootElement,
     hostElement: embeddingStrategy.hostElement,

lib/web_ui/lib/window.dart

@@ -26,6 +26,7 @@ abstract class FlutterView {
   Display get display;
   void render(Scene scene, {Size? size});
   void updateSemantics(SemanticsUpdate update) => platformDispatcher.updateSemantics(update);
+  void setSemanticsTreeEnabled(bool enabled) {}
 }
 
 abstract class SingletonFlutterWindow extends FlutterView {

lib/web_ui/test/engine/scene_view_test.dart

@@ -93,6 +93,10 @@ class StubFlutterView implements EngineFlutterView {
   void updateSemantics(ui.SemanticsUpdate update) {
   }
 
+  @override
+  void setSemanticsTreeEnabled(bool enabled) {
+  }
+
   @override
   int get viewId => throw UnimplementedError();
 

runtime/BUILD.gn

@@ -140,6 +140,7 @@ if (enable_unittests) {
       "dart_service_isolate_unittests.cc",
       "dart_vm_unittests.cc",
       "platform_isolate_manager_unittests.cc",
+      "runtime_controller_unittests.cc",
       "type_conversions_unittests.cc",
     ]
 
@@ -153,6 +154,7 @@ if (enable_unittests) {
       "//flutter/common",
       "//flutter/fml",
       "//flutter/lib/snapshot",
+      "//flutter/shell/common:shell_test_fixture_sources",
       "//flutter/skia",
       "//flutter/testing",
       "//flutter/testing:dart",

runtime/dart_isolate_unittests.cc

@@ -712,6 +712,7 @@ class FakePlatformConfigurationClient : public PlatformConfigurationClient {
               double width,
               double height) override {}
   void UpdateSemantics(SemanticsUpdate* update) override {}
+  void SetSemanticsTreeEnabled(bool enabled) override {}
   void HandlePlatformMessage(
       std::unique_ptr<PlatformMessage> message) override {}
   FontCollection& GetFontCollection() override {

runtime/fixtures/runtime_test.dart

@@ -6,6 +6,8 @@
 
 import 'dart:async';
 import 'dart:isolate';
+import 'dart:typed_data';
+import 'dart:ui';
 
 import 'split_lib_test.dart' deferred as splitlib;
 
@@ -219,3 +221,100 @@ Function createEntryPointForPlatIsoSendAndRecvTest() {
 void mainForPlatformIsolatesThrowError() {
   throw AssertionError('Error from platform isolate');
 }
+
+@pragma('vm:entry-point')
+void sendSemanticsUpdate() {
+  final SemanticsUpdateBuilder builder = SemanticsUpdateBuilder();
+  const String identifier = 'identifier';
+  const String label = 'label';
+  final List<StringAttribute> labelAttributes = <StringAttribute> [
+    SpellOutStringAttribute(range: const TextRange(start: 1, end: 2)),
+  ];
+
+  const String value = 'value';
+  final List<StringAttribute> valueAttributes = <StringAttribute> [
+    SpellOutStringAttribute(range: const TextRange(start: 2, end: 3)),
+  ];
+
+  const String increasedValue = 'increasedValue';
+  final List<StringAttribute> increasedValueAttributes = <StringAttribute> [
+    SpellOutStringAttribute(range: const TextRange(start: 4, end: 5)),
+  ];
+
+  const String decreasedValue = 'decreasedValue';
+  final List<StringAttribute> decreasedValueAttributes = <StringAttribute> [
+    SpellOutStringAttribute(range: const TextRange(start: 5, end: 6)),
+  ];
+
+  const String hint = 'hint';
+  final List<StringAttribute> hintAttributes = <StringAttribute> [
+    LocaleStringAttribute(
+      locale: const Locale('en', 'MX'), range: const TextRange(start: 0, end: 1),
+    ),
+  ];
+
+  const String tooltip = 'tooltip';
+
+  final Float64List transform = Float64List(16);
+  final Int32List childrenInTraversalOrder = Int32List(0);
+  final Int32List childrenInHitTestOrder = Int32List(0);
+  final Int32List additionalActions = Int32List(0);
+  transform[0] = 1;
+  transform[1] = 0;
+  transform[2] = 0;
+  transform[3] = 0;
+
+  transform[4] = 0;
+  transform[5] = 1;
+  transform[6] = 0;
+  transform[7] = 0;
+
+  transform[8] = 0;
+  transform[9] = 0;
+  transform[10] = 1;
+  transform[11] = 0;
+
+  transform[12] = 0;
+  transform[13] = 0;
+  transform[14] = 0;
+  transform[15] = 0;
+  builder.updateNode(
+    id: 0,
+    flags: 0,
+    actions: 0,
+    maxValueLength: 0,
+    currentValueLength: 0,
+    textSelectionBase: -1,
+    textSelectionExtent: -1,
+    platformViewId: -1,
+    scrollChildren: 0,
+    scrollIndex: 0,
+    scrollPosition: 0,
+    scrollExtentMax: 0,
+    scrollExtentMin: 0,
+    rect: const Rect.fromLTRB(0, 0, 10, 10),
+    elevation: 0,
+    thickness: 0,
+    identifier: identifier,
+    label: label,
+    labelAttributes: labelAttributes,
+    value: value,
+    valueAttributes: valueAttributes,
+    increasedValue: increasedValue,
+    increasedValueAttributes: increasedValueAttributes,
+    decreasedValue: decreasedValue,
+    decreasedValueAttributes: decreasedValueAttributes,
+    hint: hint,
+    hintAttributes: hintAttributes,
+    tooltip: tooltip,
+    textDirection: TextDirection.ltr,
+    transform: transform,
+    childrenInTraversalOrder: childrenInTraversalOrder,
+    childrenInHitTestOrder: childrenInHitTestOrder,
+    additionalActions: additionalActions,
+  );
+  _semanticsUpdate(builder.build());
+}
+
+@pragma('vm:external-name', 'SemanticsUpdate')
+external void _semanticsUpdate(SemanticsUpdate update);

runtime/runtime_controller.cc

@@ -440,11 +440,17 @@ void RuntimeController::CheckIfAllViewsRendered() {
 
 // |PlatformConfigurationClient|
 void RuntimeController::UpdateSemantics(SemanticsUpdate* update) {
-  if (platform_data_.semantics_enabled) {
+  if (semantics_tree_enabled_) {
     client_.UpdateSemantics(update->takeNodes(), update->takeActions());
   }
 }
 
+// |PlatformConfigurationClient|
+void RuntimeController::SetSemanticsTreeEnabled(bool enabled) {
+  semantics_tree_enabled_ = enabled;
+  client_.SetSemanticsTreeEnabled(enabled);
+}
+
 // |PlatformConfigurationClient|
 void RuntimeController::HandlePlatformMessage(
     std::unique_ptr<PlatformMessage> message) {

runtime/runtime_controller.h

@@ -31,6 +31,10 @@ class RuntimeDelegate;
 class View;
 class Window;
 
+namespace testing {
+class RuntimeControllerTester;
+}
+
 //------------------------------------------------------------------------------
 /// Represents an instance of a running root isolate with window bindings. In
 /// normal operation, a single instance of this object is owned by the engine
@@ -700,6 +704,7 @@ class RuntimeController : public PlatformConfigurationClient,
   std::shared_ptr<PlatformIsolateManager> platform_isolate_manager_ =
       std::shared_ptr<PlatformIsolateManager>(new PlatformIsolateManager());
   bool has_flushed_runtime_state_ = false;
+  bool semantics_tree_enabled_ = false;
 
   // Callbacks when `AddView` was called before the Dart isolate is launched.
   //
@@ -752,6 +757,9 @@ class RuntimeController : public PlatformConfigurationClient,
   // |PlatformConfigurationClient|
   void UpdateSemantics(SemanticsUpdate* update) override;
 
+  // |PlatformConfigurationClient|
+  void SetSemanticsTreeEnabled(bool enabled) override;
+
   // |PlatformConfigurationClient|
   void HandlePlatformMessage(std::unique_ptr<PlatformMessage> message) override;
 
@@ -779,6 +787,7 @@ class RuntimeController : public PlatformConfigurationClient,
   double GetScaledFontSize(double unscaled_font_size,
                            int configuration_id) const override;
 
+  friend class testing::RuntimeControllerTester;
   FML_DISALLOW_COPY_AND_ASSIGN(RuntimeController);
 };