[web] Ensure handled key event is not propagated to IME

lib/web_ui/lib/src/engine/keyboard_binding.dart

@@ -13,6 +13,7 @@ import 'browser_detection.dart';
 import 'dom.dart';
 import 'key_map.g.dart';
 import 'platform_dispatcher.dart';
+import 'raw_keyboard.dart';
 import 'semantics.dart';
 
 typedef _VoidCallback = void Function();
@@ -104,9 +105,12 @@ class KeyboardBinding {
     _addEventListener('keydown', (DomEvent domEvent) {
       final FlutterHtmlKeyboardEvent event = FlutterHtmlKeyboardEvent(domEvent as DomKeyboardEvent);
       _converter.handleEvent(event);
+      RawKeyboard.instance?.handleHtmlEvent(domEvent);
     });
-    _addEventListener('keyup', (DomEvent event) {
-      _converter.handleEvent(FlutterHtmlKeyboardEvent(event as DomKeyboardEvent));
+    _addEventListener('keyup', (DomEvent domEvent) {
+      final FlutterHtmlKeyboardEvent event = FlutterHtmlKeyboardEvent(domEvent as DomKeyboardEvent);
+      _converter.handleEvent(event);
+      RawKeyboard.instance?.handleHtmlEvent(domEvent);
     });
   }
 
@@ -209,6 +213,7 @@ class FlutterHtmlKeyboardEvent {
 
   bool getModifierState(String key) => _event.getModifierState(key);
   void preventDefault() => _event.preventDefault();
+  void stopPropagation() => _event.stopPropagation();
   bool get defaultPrevented => _event.defaultPrevented;
 }
 

lib/web_ui/lib/src/engine/raw_keyboard.dart

@@ -15,15 +15,6 @@ import 'services.dart';
 /// Provides keyboard bindings, such as the `flutter/keyevent` channel.
 class RawKeyboard {
   RawKeyboard._(this._onMacOs) {
-    _keydownListener = createDomEventListener((DomEvent event) {
-      _handleHtmlEvent(event);
-    });
-    domWindow.addEventListener('keydown', _keydownListener);
-
-    _keyupListener = createDomEventListener((DomEvent event) {
-      _handleHtmlEvent(event);
-    });
-    domWindow.addEventListener('keyup', _keyupListener);
     registerHotRestartListener(() {
       dispose();
     });
@@ -34,6 +25,9 @@ class RawKeyboard {
   /// Use the [instance] getter to get the singleton after calling this method.
   static void initialize({bool onMacOs = false}) {
     _instance ??= RawKeyboard._(onMacOs);
+    // KeyboardBinding is responsible for forwarding the keyboard
+    // events to the RawKeyboard handler.
+    KeyboardBinding.initInstance();
   }
 
   /// The [RawKeyboard] singleton.
@@ -46,24 +40,16 @@ class RawKeyboard {
   /// if no repeat events were received.
   final Map<String, Timer> _keydownTimers = <String, Timer>{};
 
-  DomEventListener? _keydownListener;
-  DomEventListener? _keyupListener;
-
   /// Uninitializes the [RawKeyboard] singleton.
   ///
   /// After calling this method this object becomes unusable and [instance]
   /// becomes `null`. Call [initialize] again to initialize a new singleton.
   void dispose() {
-    domWindow.removeEventListener('keydown', _keydownListener);
-    domWindow.removeEventListener('keyup', _keyupListener);
-
     for (final String key in _keydownTimers.keys) {
       _keydownTimers[key]!.cancel();
     }
     _keydownTimers.clear();
 
-    _keydownListener = null;
-    _keyupListener = null;
     _instance = null;
   }
 
@@ -96,7 +82,7 @@ class RawKeyboard {
     return event.type == 'keydown' && event.key == 'Tab' && event.isComposing;
   }
 
-  void _handleHtmlEvent(DomEvent domEvent) {
+  void handleHtmlEvent(DomEvent domEvent) {
     if (!domInstanceOfString(domEvent, 'KeyboardEvent')) {
       return;
     }
@@ -158,6 +144,7 @@ class RawKeyboard {
         if (jsonResponse['handled'] as bool) {
           // If the framework handled it, then don't propagate it any further.
           event.preventDefault();
+          event.stopPropagation();
         }
       },
     );

lib/web_ui/test/common/keyboard_test_common.dart

@@ -22,6 +22,7 @@ class MockKeyboardEvent implements FlutterHtmlKeyboardEvent {
     bool altGrKey = false,
     this.location = 0,
     this.onPreventDefault,
+    this.onStopPropagation,
   }) : modifierState =
         <String>{
           if (altKey) 'Alt',
@@ -84,6 +85,12 @@ class MockKeyboardEvent implements FlutterHtmlKeyboardEvent {
   bool get defaultPrevented => _defaultPrevented;
   bool _defaultPrevented = false;
 
+  @override
+  void stopPropagation() {
+    onStopPropagation?.call();
+  }
+  VoidCallback? onStopPropagation;
+
   static bool get lastDefaultPrevented => _lastEvent?.defaultPrevented ?? false;
   static MockKeyboardEvent? _lastEvent;
 }

lib/web_ui/test/engine/raw_keyboard_test.dart

@@ -52,6 +52,10 @@ void testMain() {
 
       DomKeyboardEvent event;
 
+      // Dispatch a keydown event first so that KeyboardBinding will recognize the keyup event.
+      // and will not set preventDefault on it.
+      event = dispatchKeyboardEvent('keydown', key: 'SomeKey', code: 'SomeCode', keyCode: 1);
+
       event = dispatchKeyboardEvent('keyup', key: 'SomeKey', code: 'SomeCode', keyCode: 1);
 
       expect(event.defaultPrevented, isFalse);

lib/web_ui/test/engine/text_editing_test.dart

@@ -12,12 +12,14 @@ import 'package:test/test.dart';
 import 'package:ui/src/engine.dart' show flutterViewEmbedder;
 import 'package:ui/src/engine/browser_detection.dart';
 import 'package:ui/src/engine/dom.dart';
+import 'package:ui/src/engine/raw_keyboard.dart';
 import 'package:ui/src/engine/services.dart';
 import 'package:ui/src/engine/text_editing/autofill_hint.dart';
 import 'package:ui/src/engine/text_editing/input_type.dart';
 import 'package:ui/src/engine/text_editing/text_editing.dart';
 import 'package:ui/src/engine/util.dart';
 import 'package:ui/src/engine/vector_math.dart';
+import 'package:ui/ui.dart' as ui;
 
 import '../common/spy.dart';
 import '../common/test_initialization.dart';
@@ -370,6 +372,52 @@ Future<void> testMain() async {
       expect(lastInputAction, 'TextInputAction.done');
     });
 
+   test('handling keyboard event prevents triggering input action', () {
+      final ui.PlatformMessageCallback? savedCallback = ui.window.onPlatformMessage;
+
+      bool markTextEventHandled = false;
+      ui.window.onPlatformMessage = (String channel, ByteData? data,
+          ui.PlatformMessageResponseCallback? callback) {
+        final ByteData response = const JSONMessageCodec()
+            .encodeMessage(<String, dynamic>{'handled': markTextEventHandled})!;
+        callback!(response);
+      };
+      RawKeyboard.initialize();
+
+      final InputConfiguration config = InputConfiguration();
+      editingStrategy!.enable(
+        config,
+        onChange: trackEditingState,
+        onAction: trackInputAction,
+      );
+
+      // No input action so far.
+      expect(lastInputAction, isNull);
+
+      markTextEventHandled = true;
+      dispatchKeyboardEvent(
+        editingStrategy!.domElement!,
+        'keydown',
+        keyCode: _kReturnKeyCode,
+      );
+
+      // Input action prevented by platform message callback.
+      expect(lastInputAction, isNull);
+
+      markTextEventHandled = false;
+      dispatchKeyboardEvent(
+        editingStrategy!.domElement!,
+        'keydown',
+        keyCode: _kReturnKeyCode,
+      );
+
+      // Input action received.
+      expect(lastInputAction, 'TextInputAction.done');
+
+      ui.window.onPlatformMessage = savedCallback;
+      RawKeyboard.instance?.dispose();
+    });
+
     test('Triggers input action in multi-line mode', () {
       final InputConfiguration config = InputConfiguration(
         inputType: EngineInputType.multiline,

third_party/web_locale_keymap/lib/web_locale_keymap/locale_keymap.dart

@@ -41,6 +41,9 @@ class LocaleKeymap {
       return eventKeyCode;
     }
     if (result == null) {
+      if ((eventCode ?? '').isEmpty && (eventKey ?? '').isEmpty) {
+        return null;
+      }
       final int? heuristicResult = heuristicMapper(eventCode ?? '', eventKey ?? '');
       if (heuristicResult != null) {
         return heuristicResult;