Shortcut activator (#78522)

This PR introduced a new class, ShortcutActivator, and refactored the the definition and lookup system of shortcuts, in order to solve a few issues of the previous algorithm.

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

@@ -132,8 +132,8 @@ abstract class RawKeyEventData {
   ///
   /// If the modifier key wasn't pressed at the time of this event, returns
   /// null. If the given key only appears in one place on the keyboard, returns
-  /// [KeyboardSide.all] if pressed. Never returns [KeyboardSide.any], because
-  /// that doesn't make sense in this context.
+  /// [KeyboardSide.all] if pressed. If the given platform does not specify
+  /// the side, return [KeyboardSide.any].
   KeyboardSide? getModifierSide(ModifierKey key);
 
   /// Returns true if a CTRL modifier key was pressed at the time of this event,
@@ -734,15 +734,38 @@ class RawKeyboard {
   };
 
   void _synchronizeModifiers(RawKeyEvent event) {
-    // Don't send any key events for these changes, since there *should* be
-    // separate events for each modifier key down/up that occurs while the app
-    // has focus. This is just to synchronize the modifier keys when they are
-    // pressed/released while the app doesn't have focus, to make sure that
-    // _keysPressed reflects reality at all times.
+    // Compare modifier states to the ground truth as specified by
+    // [RawKeyEvent.data.modifiersPressed] and update unsynchronized ones.
+    //
+    // This function will update the state of modifier keys in `_keysPressed` so
+    // that they match the ones given by [RawKeyEvent.data.modifiersPressed].
+    // For a `modifiersPressed` result of anything but [KeyboardSide.any], the
+    // states in `_keysPressed` will be updated to exactly match the result,
+    // i.e. exactly one of "no down", "left down", "right down" or "both down".
+    //
+    // If `modifiersPressed` returns [KeyboardSide.any], the states in
+    // `_keysPressed` will be updated to a rough match, i.e. "either side down"
+    // or "no down". If `_keysPressed` has no modifier down, a
+    // [KeyboardSide.any] will synchronize by forcing the left modifier down. If
+    // `_keysPressed` has any modifier down, a [KeyboardSide.any] will not cause
+    // a state change.
 
     final Map<ModifierKey, KeyboardSide?> modifiersPressed = event.data.modifiersPressed;
     final Map<PhysicalKeyboardKey, LogicalKeyboardKey> modifierKeys = <PhysicalKeyboardKey, LogicalKeyboardKey>{};
+    // Physical keys that whose modifiers are pressed at any side.
+    final Set<PhysicalKeyboardKey> anySideKeys = <PhysicalKeyboardKey>{};
+    final Set<PhysicalKeyboardKey> keysPressedAfterEvent = <PhysicalKeyboardKey>{
+      ..._keysPressed.keys,
+      if (event is RawKeyDownEvent) event.physicalKey,
+    };
     for (final ModifierKey key in modifiersPressed.keys) {
+      if (modifiersPressed[key] == KeyboardSide.any) {
+        final Set<PhysicalKeyboardKey>? thisModifierKeys = _modifierKeyMap[_ModifierSidePair(key, KeyboardSide.all)];
+        anySideKeys.addAll(thisModifierKeys!);
+        if (thisModifierKeys.any(keysPressedAfterEvent.contains)) {
+          continue;
+        }
+      }
       final Set<PhysicalKeyboardKey>? mappedKeys = _modifierKeyMap[_ModifierSidePair(key, modifiersPressed[key])];
       assert((){
         if (mappedKeys == null) {
@@ -764,7 +787,9 @@ class RawKeyboard {
         modifierKeys[physicalModifier] = _allModifiers[physicalModifier]!;
       }
     }
-    _allModifiersExceptFn.keys.forEach(_keysPressed.remove);
+    _allModifiersExceptFn.keys
+      .where((PhysicalKeyboardKey key) => !anySideKeys.contains(key))
+      .forEach(_keysPressed.remove);
     if (event.data is! RawKeyEventDataFuchsia && event.data is! RawKeyEventDataMacOs) {
       // On Fuchsia and macOS, the Fn key is not considered a modifier key.
       _keysPressed.remove(PhysicalKeyboardKey.fn);

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

@@ -119,7 +119,7 @@ class RawKeyEventDataWeb extends RawKeyEventData {
     //
     // See <https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/getModifierState>
     // for more information.
-    return KeyboardSide.all;
+    return KeyboardSide.any;
   }
 
   // Modifier key masks.

packages/flutter/test/services/raw_keyboard_test.dart

@@ -354,16 +354,15 @@ void main() {
 
     testWidgets('keysPressed modifiers are synchronized with key events on web', (WidgetTester tester) async {
       expect(RawKeyboard.instance.keysPressed, isEmpty);
-      // Generate the data for a regular key down event.
+      // Generate the data for a regular key down event. Change the modifiers so
+      // that they show the shift key as already down when this event is
+      // received, but it's not in keysPressed yet.
       final Map<String, dynamic> data = KeyEventSimulator.getKeyData(
         LogicalKeyboardKey.keyA,
         platform: 'web',
         isDown: true,
-      );
-      // Change the modifiers so that they show the shift key as already down
-      // when this event is received, but it's not in keysPressed yet.
-      data['metaState'] |= RawKeyEventDataWeb.modifierShift;
-      // dispatch the modified data.
+      )..['metaState'] |= RawKeyEventDataWeb.modifierShift;
+      // Dispatch the modified data.
       await ServicesBinding.instance!.defaultBinaryMessenger.handlePlatformMessage(
         SystemChannels.keyEvent.name,
         SystemChannels.keyEvent.codec.encodeMessage(data),
@@ -374,13 +373,71 @@ void main() {
         equals(
           <LogicalKeyboardKey>{
             LogicalKeyboardKey.shiftLeft,
-            // Web doesn't distinguish between left and right keys, so they're
-            // all shown as down when either is pressed.
-            LogicalKeyboardKey.shiftRight,
             LogicalKeyboardKey.keyA,
           },
         ),
       );
+
+      // Generate the data for a regular key up event. Don't set the modifiers
+      // for shift so that they show the shift key as already up when this event
+      // is received, and it's in keysPressed.
+      final Map<String, dynamic> data2 = KeyEventSimulator.getKeyData(
+        LogicalKeyboardKey.keyA,
+        platform: 'web',
+        isDown: false,
+      )..['metaState'] = 0;
+      // Dispatch the modified data.
+      await ServicesBinding.instance!.defaultBinaryMessenger.handlePlatformMessage(
+        SystemChannels.keyEvent.name,
+        SystemChannels.keyEvent.codec.encodeMessage(data2),
+        (ByteData? data) {},
+      );
+      expect(
+        RawKeyboard.instance.keysPressed,
+        equals(
+          <LogicalKeyboardKey>{},
+        ),
+      );
+
+      // Press right modifier key
+      final Map<String, dynamic> data3 = KeyEventSimulator.getKeyData(
+        LogicalKeyboardKey.shiftRight,
+        platform: 'web',
+        isDown: true,
+      )..['metaState'] |= RawKeyEventDataWeb.modifierShift;
+      // Dispatch the modified data.
+      await ServicesBinding.instance!.defaultBinaryMessenger.handlePlatformMessage(
+        SystemChannels.keyEvent.name,
+        SystemChannels.keyEvent.codec.encodeMessage(data3),
+        (ByteData? data) {},
+      );
+      expect(
+        RawKeyboard.instance.keysPressed,
+        equals(
+          <LogicalKeyboardKey>{
+            LogicalKeyboardKey.shiftRight,
+          },
+        ),
+      );
+
+      // Release the key
+      final Map<String, dynamic> data4 = KeyEventSimulator.getKeyData(
+        LogicalKeyboardKey.shiftRight,
+        platform: 'web',
+        isDown: false,
+      )..['metaState'] = 0;
+      // Dispatch the modified data.
+      await ServicesBinding.instance!.defaultBinaryMessenger.handlePlatformMessage(
+        SystemChannels.keyEvent.name,
+        SystemChannels.keyEvent.codec.encodeMessage(data4),
+        (ByteData? data) {},
+      );
+      expect(
+        RawKeyboard.instance.keysPressed,
+        equals(
+          <LogicalKeyboardKey>{},
+        ),
+      );
     });
 
     testWidgets('sided modifiers without a side set return all sides on Android', (WidgetTester tester) async {
@@ -572,7 +629,7 @@ void main() {
       );
     }, skip: isBrowser); // This is a GLFW-specific test.
 
-    testWidgets('sided modifiers without a side set return all sides on web', (WidgetTester tester) async {
+    testWidgets('sided modifiers without a side set return left sides on web', (WidgetTester tester) async {
       expect(RawKeyboard.instance.keysPressed, isEmpty);
       // Generate the data for a regular key down event.
       final Map<String, dynamic> data = KeyEventSimulator.getKeyData(
@@ -597,13 +654,9 @@ void main() {
         equals(
           <LogicalKeyboardKey>{
             LogicalKeyboardKey.shiftLeft,
-            LogicalKeyboardKey.shiftRight,
             LogicalKeyboardKey.altLeft,
-            LogicalKeyboardKey.altRight,
             LogicalKeyboardKey.controlLeft,
-            LogicalKeyboardKey.controlRight,
             LogicalKeyboardKey.metaLeft,
-            LogicalKeyboardKey.metaRight,
             LogicalKeyboardKey.keyA,
           },
         ),

packages/flutter_test/lib/src/controller.dart

@@ -21,6 +21,8 @@ import 'test_pointer.dart';
 /// This value must be greater than [kTouchSlop].
 const double kDragSlopDefault = 20.0;
 
+const String _defaultPlatform = kIsWeb ? 'web' : 'android';
+
 /// Class that programmatically interacts with widgets.
 ///
 /// For a variant of this class suited specifically for unit tests, see
@@ -976,8 +978,8 @@ abstract class WidgetController {
   ///
   /// Specify `platform` as one of the platforms allowed in
   /// [Platform.operatingSystem] to make the event appear to be from that type
-  /// of system. Defaults to "android". Must not be null. Some platforms (e.g.
-  /// Windows, iOS) are not yet supported.
+  /// of system. Defaults to "web" on web, and "android" everywhere else. Must not be
+  /// null. Some platforms (e.g. Windows, iOS) are not yet supported.
   ///
   /// Keys that are down when the test completes are cleared after each test.
   ///
@@ -991,7 +993,7 @@ abstract class WidgetController {
   ///
   ///  - [sendKeyDownEvent] to simulate only a key down event.
   ///  - [sendKeyUpEvent] to simulate only a key up event.
-  Future<bool> sendKeyEvent(LogicalKeyboardKey key, { String platform = 'android' }) async {
+  Future<bool> sendKeyEvent(LogicalKeyboardKey key, { String platform = _defaultPlatform }) async {
     assert(platform != null);
     final bool handled = await simulateKeyDownEvent(key, platform: platform);
     // Internally wrapped in async guard.
@@ -1006,8 +1008,8 @@ abstract class WidgetController {
   ///
   /// Specify `platform` as one of the platforms allowed in
   /// [Platform.operatingSystem] to make the event appear to be from that type
-  /// of system. Defaults to "android". Must not be null. Some platforms (e.g.
-  /// Windows, iOS) are not yet supported.
+  /// of system. Defaults to "web" on web, and "android" everywhere else. Must not be
+  /// null. Some platforms (e.g. Windows, iOS) are not yet supported.
   ///
   /// Keys that are down when the test completes are cleared after each test.
   ///
@@ -1017,7 +1019,7 @@ abstract class WidgetController {
   ///
   ///  - [sendKeyUpEvent] to simulate the corresponding key up event.
   ///  - [sendKeyEvent] to simulate both the key up and key down in the same call.
-  Future<bool> sendKeyDownEvent(LogicalKeyboardKey key, { String platform = 'android' }) async {
+  Future<bool> sendKeyDownEvent(LogicalKeyboardKey key, { String platform = _defaultPlatform }) async {
     assert(platform != null);
     // Internally wrapped in async guard.
     return simulateKeyDownEvent(key, platform: platform);
@@ -1029,8 +1031,8 @@ abstract class WidgetController {
   /// not from a soft keyboard.
   ///
   /// Specify `platform` as one of the platforms allowed in
-  /// [Platform.operatingSystem] to make the event appear to be from that type
-  /// of system. Defaults to "android". May not be null.
+  /// [Platform.operatingSystem] to make the event appear to be from that type of
+  /// system. Defaults to "web" on web, and "android" everywhere else. May not be null.
   ///
   /// Returns true if the key event was handled by the framework.
   ///
@@ -1038,7 +1040,7 @@ abstract class WidgetController {
   ///
   ///  - [sendKeyDownEvent] to simulate the corresponding key down event.
   ///  - [sendKeyEvent] to simulate both the key up and key down in the same call.
-  Future<bool> sendKeyUpEvent(LogicalKeyboardKey key, { String platform = 'android' }) async {
+  Future<bool> sendKeyUpEvent(LogicalKeyboardKey key, { String platform = _defaultPlatform }) async {
     assert(platform != null);
     // Internally wrapped in async guard.
     return simulateKeyUpEvent(key, platform: platform);