[RawKeyboard] Allow inconsistent modifiers for Web (#114499)

Co-authored-by: Bruno Leroux <bruno.leroux@gmail.com>

dev/tools/gen_keycodes/data/keyboard_key.tmpl

@@ -209,7 +209,7 @@ class LogicalKeyboardKey extends KeyboardKey {
   /// Auto-generated IDs should be a rare occurrence: Flutter supports most keys.
   ///
   /// Keys that generate Unicode characters (even if unknown to Flutter) will
-  /// not return true for `isAutogenerated`, since they will be assigned a
+  /// not return true for [isAutogenerated], since they will be assigned a
   /// Unicode-based code that will remain stable.
   ///
   /// If Flutter adds support for a previously unsupported key code, the ID it

dev/tools/gen_keycodes/data/web_logical_location_mapping.json

@@ -29,5 +29,6 @@
   "Shift": ["ShiftLeft", "ShiftLeft", "ShiftRight", null],
   "Control": ["ControlLeft", "ControlLeft", "ControlRight", null],
   "Alt": ["AltLeft", "AltLeft", "AltRight", null],
+  "AltGraph": ["AltGraph", null, "AltGraph", null],
   "Meta": ["MetaLeft", "MetaLeft", "MetaRight", null]
 }

packages/flutter/lib/src/services/keyboard_maps.g.dart

@@ -2755,6 +2755,7 @@ const Map<String, List<LogicalKeyboardKey?>> kWebLocationMap = <String, List<Log
   '8': <LogicalKeyboardKey?>[LogicalKeyboardKey.digit8, null, null, LogicalKeyboardKey.numpad8],
   '9': <LogicalKeyboardKey?>[LogicalKeyboardKey.digit9, null, null, LogicalKeyboardKey.numpad9],
   'Alt': <LogicalKeyboardKey?>[LogicalKeyboardKey.altLeft, LogicalKeyboardKey.altLeft, LogicalKeyboardKey.altRight, null],
+  'AltGraph': <LogicalKeyboardKey?>[LogicalKeyboardKey.altGraph, null, LogicalKeyboardKey.altGraph, null],
   'ArrowDown': <LogicalKeyboardKey?>[LogicalKeyboardKey.arrowDown, null, null, LogicalKeyboardKey.numpad2],
   'ArrowLeft': <LogicalKeyboardKey?>[LogicalKeyboardKey.arrowLeft, null, null, LogicalKeyboardKey.numpad4],
   'ArrowRight': <LogicalKeyboardKey?>[LogicalKeyboardKey.arrowRight, null, null, LogicalKeyboardKey.numpad6],

packages/flutter/lib/src/services/raw_keyboard.dart

@@ -848,6 +848,12 @@ class RawKeyboard {
           _keysPressed[event.physicalKey] = logicalKey;
         }
       }
+      // On Web, PhysicalKeyboardKey.altRight can be map to LogicalKeyboardKey.altGraph or
+      // LogicalKeyboardKey.altRight:
+      // https://github.com/flutter/flutter/issues/113836
+      if (event.data is RawKeyEventDataWeb && event.physicalKey == PhysicalKeyboardKey.altRight) {
+        _keysPressed[event.physicalKey] = event.logicalKey;
+      }
     }
   }
 

packages/flutter/test/services/raw_keyboard_test.dart

@@ -842,6 +842,64 @@ void main() {
       expect(RawKeyboard.instance.keysPressed, contains(LogicalKeyboardKey.capsLock));
     }, skip: isBrowser); // [intended] This is an Android-specific group.
 
+    testWidgets('Allows inconsistent modifier for Web - Alt graph', (WidgetTester _) async {
+      // Regression test for https://github.com/flutter/flutter/issues/113836
+      final List<RawKeyEvent> events = <RawKeyEvent>[];
+      RawKeyboard.instance.addListener(events.add);
+      addTearDown(() {
+        RawKeyboard.instance.removeListener(events.add);
+      });
+      await TestDefaultBinaryMessengerBinding.instance!.defaultBinaryMessenger.handlePlatformMessage(
+        SystemChannels.keyEvent.name,
+        SystemChannels.keyEvent.codec.encodeMessage(const <String, dynamic>{
+          'type': 'keydown',
+          'keymap': 'web',
+          'code': 'AltRight',
+          'key': 'AltGraph',
+          'location': 2,
+          'metaState': 0,
+          'keyCode': 225,
+        }),
+        (ByteData? data) { },
+      );
+
+      expect(events, hasLength(1));
+      final RawKeyEvent altRightKey = events[0];
+      final RawKeyEventDataWeb data = altRightKey.data as RawKeyEventDataWeb;
+      expect(data.physicalKey, equals(PhysicalKeyboardKey.altRight));
+      expect(data.logicalKey, equals(LogicalKeyboardKey.altGraph));
+      expect(RawKeyboard.instance.keysPressed, contains(LogicalKeyboardKey.altGraph));
+    }, skip: !isBrowser); // [intended] This is a Browser-specific test.
+
+    testWidgets('Allows inconsistent modifier for Web - Alt right', (WidgetTester _) async {
+      // Regression test for https://github.com/flutter/flutter/issues/113836
+      final List<RawKeyEvent> events = <RawKeyEvent>[];
+      RawKeyboard.instance.addListener(events.add);
+      addTearDown(() {
+        RawKeyboard.instance.removeListener(events.add);
+      });
+      await TestDefaultBinaryMessengerBinding.instance!.defaultBinaryMessenger.handlePlatformMessage(
+        SystemChannels.keyEvent.name,
+        SystemChannels.keyEvent.codec.encodeMessage(const <String, dynamic>{
+          'type': 'keydown',
+          'keymap': 'web',
+          'code': 'AltRight',
+          'key': 'Alt',
+          'location': 2,
+          'metaState': 0,
+          'keyCode': 225,
+        }),
+        (ByteData? data) { },
+      );
+
+      expect(events, hasLength(1));
+      final RawKeyEvent altRightKey = events[0];
+      final RawKeyEventDataWeb data = altRightKey.data as RawKeyEventDataWeb;
+      expect(data.physicalKey, equals(PhysicalKeyboardKey.altRight));
+      expect(data.logicalKey, equals(LogicalKeyboardKey.altRight));
+      expect(RawKeyboard.instance.keysPressed, contains(LogicalKeyboardKey.altRight));
+    }, skip: !isBrowser); // [intended] This is a Browser-specific test.
+
     testWidgets('Dispatch events to all handlers', (WidgetTester tester) async {
       final FocusNode focusNode = FocusNode();
       final List<int> logs = <int>[];