Fixed a case where the KeyUp event is not called by Command+Key on MacOS

shell/platform/darwin/macos/framework/Source/FlutterViewController.mm

@@ -619,21 +619,23 @@ - (void)listenForMetaModifiedKeyUpEvents {
     return;
   }
   FlutterViewController* __weak weakSelf = self;
-  _keyUpMonitor = [NSEvent
-      addLocalMonitorForEventsMatchingMask:NSEventMaskKeyUp
-                                   handler:^NSEvent*(NSEvent* event) {
-                                     // Intercept keyUp only for events triggered on the current
-                                     // view or textInputPlugin.
-                                     NSResponder* firstResponder = [[event window] firstResponder];
-                                     if (weakSelf.viewLoaded && weakSelf.flutterView &&
-                                         (firstResponder == weakSelf.flutterView ||
-                                          firstResponder == weakSelf.textInputPlugin) &&
-                                         ([event modifierFlags] & NSEventModifierFlagCommand) &&
-                                         ([event type] == NSEventTypeKeyUp)) {
-                                       [weakSelf keyUp:event];
-                                     }
-                                     return event;
-                                   }];
+  _keyUpMonitor = [NSEvent addLocalMonitorForEventsMatchingMask:NSEventMaskKeyUp
+                                                        handler:^NSEvent*(NSEvent* event) {
+                                                          return [weakSelf handleKeyUpEvent:event];
+                                                        }];
+}
+
+- (NSEvent*)handleKeyUpEvent:(NSEvent*)event {
+  // Intercept keyUp only for events triggered on the current
+  // view or textInputPlugin.
+  NSResponder* firstResponder = [[event window] firstResponder];
+  if (self.viewLoaded && self.flutterView &&
+      (firstResponder == self.view || firstResponder == self.flutterView ||
+       firstResponder == self.textInputPlugin) &&
+      ([event modifierFlags] & NSEventModifierFlagCommand) && ([event type] == NSEventTypeKeyUp)) {
+    [self keyUp:event];
+  }
+  return event;
 }
 
 - (void)configureTrackingArea {

shell/platform/darwin/macos/framework/Source/FlutterViewControllerTest.mm

@@ -70,6 +70,7 @@ - (bool)testFlutterViewIsConfigured;
 - (bool)testLookupKeyAssets;
 - (bool)testLookupKeyAssetsWithPackage;
 - (bool)testViewControllerIsReleased;
+- (bool)testListenForMetaModifiedKeyUpEvents;
 
 + (void)respondFalseForSendEvent:(const FlutterKeyEvent&)event
                         callback:(nullable FlutterKeyEventCallback)callback
@@ -256,6 +257,10 @@ id MockGestureEvent(NSEventType type, NSEventPhase phase, double magnification,
   ASSERT_TRUE([[FlutterViewControllerTestObjC alloc] testViewControllerIsReleased]);
 }
 
+TEST(FlutterViewControllerTest, testListenForMetaModifiedKeyUpEvents) {
+  ASSERT_TRUE([[FlutterViewControllerTestObjC alloc] testListenForMetaModifiedKeyUpEvents]);
+}
+
 }  // namespace flutter::testing
 
 #pragma mark - FlutterViewControllerTestObjC
@@ -1041,4 +1046,64 @@ - (bool)testViewControllerIsReleased {
   return true;
 }
 
+- (bool)testListenForMetaModifiedKeyUpEvents {
+  FlutterViewController* viewController = flutter::testing::CreateMockViewController();
+  OCMStub([viewController keyUp:[OCMArg any]]).andDo(nil);
+  [viewController loadView];
+
+  // Creates a NSWindow so that sub view can be first responder.
+  NSWindow* window = [[NSWindow alloc] initWithContentRect:NSMakeRect(0, 0, 800, 600)
+                                                 styleMask:NSBorderlessWindowMask
+                                                   backing:NSBackingStoreBuffered
+                                                     defer:NO];
+  window.contentView = viewController.view;
+  NSView* dummyView = [[NSView alloc] initWithFrame:CGRectZero];
+  [viewController.view addSubview:dummyView];
+  // Attaches FlutterTextInputPlugin to the view;
+  [dummyView addSubview:viewController.textInputPlugin];
+
+  // Command + 1
+  NSEvent* key1Up = [NSEvent keyEventWithType:NSEventTypeKeyUp
+                                     location:NSZeroPoint
+                                modifierFlags:0x00100000
+                                    timestamp:0
+                                 windowNumber:0
+                                      context:nil
+                                   characters:@"1"
+                  charactersIgnoringModifiers:@"1"
+                                    isARepeat:FALSE
+                                      keyCode:0];
+  [key1Up setValue:window forKey:@"_window"];
+
+  // Should not call keyup evnet by NSView.
+  EXPECT_TRUE([window makeFirstResponder:dummyView]);
+  [viewController handleKeyUpEvent:key1Up];
+
+  @try {
+    OCMVerify(  // NOLINT(google-objc-avoid-throwing-exception)
+        never(), [viewController keyUp:[OCMArg any]]);
+  } @catch (...) {
+    return false;
+  }
+
+  // Should call keyup evnet.
+  EXPECT_TRUE([window makeFirstResponder:viewController.textInputPlugin]);
+  [viewController handleKeyUpEvent:key1Up];
+
+  EXPECT_TRUE([window makeFirstResponder:viewController.view]);
+  [viewController handleKeyUpEvent:key1Up];
+
+  EXPECT_TRUE([window makeFirstResponder:viewController.flutterView]);
+  [viewController handleKeyUpEvent:key1Up];
+
+  @try {
+    OCMVerify(  // NOLINT(google-objc-avoid-throwing-exception)
+        times(3), [viewController keyUp:[OCMArg any]]);
+  } @catch (...) {
+    return false;
+  }
+
+  return true;
+}
+
 @end

shell/platform/darwin/macos/framework/Source/FlutterViewController_Internal.h

@@ -84,4 +84,6 @@
 - (nonnull FlutterView*)createFlutterViewWithMTLDevice:(nonnull id<MTLDevice>)device
                                           commandQueue:(nonnull id<MTLCommandQueue>)commandQueue;
 
+- (nullable NSEvent*)handleKeyUpEvent:(nonnull NSEvent*)event;
+
 @end