Added keyEvent support for iOS 13.4+

shell/platform/darwin/ios/framework/Headers/FlutterEngine.h

@@ -322,6 +322,14 @@ FLUTTER_EXPORT
  */
 @property(nonatomic, readonly) FlutterBasicMessageChannel* settingsChannel;
 
+/**
+ * The `FlutterBasicMessageChannel` used for communicating key events
+ * from physical keyboards
+ *
+ * Can be nil after `destroyContext` is called.
+ */
+@property(nonatomic, readonly) FlutterBasicMessageChannel* keyEventChannel;
+
 /**
  * The `NSURL` of the observatory for the service isolate.
  *

shell/platform/darwin/ios/framework/Source/FlutterEngine.mm

@@ -81,6 +81,7 @@ @implementation FlutterEngine {
   fml::scoped_nsobject<FlutterBasicMessageChannel> _lifecycleChannel;
   fml::scoped_nsobject<FlutterBasicMessageChannel> _systemChannel;
   fml::scoped_nsobject<FlutterBasicMessageChannel> _settingsChannel;
+  fml::scoped_nsobject<FlutterBasicMessageChannel> _keyEventChannel;
 
   int64_t _nextTextureId;
 
@@ -350,6 +351,9 @@ - (FlutterBasicMessageChannel*)systemChannel {
 - (FlutterBasicMessageChannel*)settingsChannel {
   return _settingsChannel.get();
 }
+- (FlutterBasicMessageChannel*)keyEventChannel {
+  return _keyEventChannel.get();
+}
 
 - (NSURL*)observatoryUrl {
   return [_publisher.get() url];
@@ -364,6 +368,7 @@ - (void)resetChannels {
   _lifecycleChannel.reset();
   _systemChannel.reset();
   _settingsChannel.reset();
+  _keyEventChannel.reset();
 }
 
 - (void)startProfiler:(NSString*)threadLabel {
@@ -436,6 +441,11 @@ - (void)setupChannels {
       binaryMessenger:self.binaryMessenger
                 codec:[FlutterJSONMessageCodec sharedInstance]]);
 
+  _keyEventChannel.reset([[FlutterBasicMessageChannel alloc]
+         initWithName:@"flutter/keyevent"
+      binaryMessenger:self.binaryMessenger
+                codec:[FlutterJSONMessageCodec sharedInstance]]);
+
   _textInputPlugin.reset([[FlutterTextInputPlugin alloc] init]);
   _textInputPlugin.get().textInputDelegate = self;
 

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

@@ -1024,6 +1024,58 @@ - (void)keyboardWillBeHidden:(NSNotification*)notification {
   [self updateViewportMetrics];
 }
 
+- (void)dispatchPresses:(NSSet<UIPress*>*)presses API_AVAILABLE(ios(13.4)) {
+  if (@available(iOS 13.4, *)) {
+    for (UIPress* press in presses) {
+      if (press.key == nil || press.phase == UIPressPhaseStationary ||
+          press.phase == UIPressPhaseChanged) {
+        continue;
+      }
+      NSMutableDictionary* keyMessage = [@{
+        @"keymap" : @"ios",
+        @"type" : @"unknown",
+        @"keyCode" : @(press.key.keyCode),
+        @"modifiers" : @(press.key.modifierFlags),
+        @"characters" : press.key.characters,
+        @"charactersIgnoringModifiers" : press.key.charactersIgnoringModifiers
+      } mutableCopy];
+
+      if (press.phase == UIPressPhaseBegan) {
+        keyMessage[@"type"] = @"keydown";
+      } else if (press.phase == UIPressPhaseEnded || press.phase == UIPressPhaseCancelled) {
+        keyMessage[@"type"] = @"keyup";
+      }
+
+      [[_engine.get() keyEventChannel] sendMessage:keyMessage];
+    }
+  }
+}
+
+- (void)pressesBegan:(NSSet<UIPress*>*)presses withEvent:(UIEvent*)event API_AVAILABLE(ios(9.0)) {
+  if (@available(iOS 13.4, *)) {
+    [self dispatchPresses:presses];
+  }
+}
+
+- (void)pressesChanged:(NSSet<UIPress*>*)presses withEvent:(UIEvent*)event API_AVAILABLE(ios(9.0)) {
+  if (@available(iOS 13.4, *)) {
+    [self dispatchPresses:presses];
+  }
+}
+
+- (void)pressesEnded:(NSSet<UIPress*>*)presses withEvent:(UIEvent*)event API_AVAILABLE(ios(9.0)) {
+  if (@available(iOS 13.4, *)) {
+    [self dispatchPresses:presses];
+  }
+}
+
+- (void)pressesCancelled:(NSSet<UIPress*>*)presses
+               withEvent:(UIEvent*)event API_AVAILABLE(ios(9.0)) {
+  if (@available(iOS 13.4, *)) {
+    [self dispatchPresses:presses];
+  }
+}
+
 #pragma mark - Orientation updates
 
 - (void)onOrientationPreferencesUpdated:(NSNotification*)notification {

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

@@ -62,6 +62,7 @@ - (UIAccessibilityContrast)accessibilityContrast;
 @interface FlutterViewController (Tests)
 - (void)surfaceUpdated:(BOOL)appeared;
 - (void)performOrientationUpdate:(UIInterfaceOrientationMask)new_preferences;
+- (void)dispatchPresses:(NSSet<UIPress*>*)presses;
 @end
 
 @implementation FlutterViewControllerTest
@@ -549,4 +550,150 @@ - (void)testNotifyLowMemory {
   OCMVerify([engine notifyLowMemory]);
 }
 
+- (void)testValidKeyUpEvent API_AVAILABLE(ios(13.4)) {
+  if (@available(iOS 13.4, *)) {
+    // noop
+  } else {
+    return;
+  }
+
+  id engine = OCMClassMock([FlutterEngine class]);
+
+  id keyEventChannel = OCMClassMock([FlutterBasicMessageChannel class]);
+  OCMStub([engine keyEventChannel]).andReturn(keyEventChannel);
+
+  FlutterViewController* vc = [[FlutterViewController alloc] initWithEngine:engine
+                                                                    nibName:nil
+                                                                     bundle:nil];
+
+  id testSet = [self fakeUiPressSetForPhase:UIPressPhaseBegan
+                                    keyCode:UIKeyboardHIDUsageKeyboardA
+                              modifierFlags:UIKeyModifierShift
+                                 characters:@"a"
+                charactersIgnoringModifiers:@"A"];
+
+  // Exercise behavior under test.
+  [vc dispatchPresses:testSet];
+
+  // Verify behavior.
+  OCMVerify([keyEventChannel
+      sendMessage:[OCMArg checkWithBlock:^BOOL(id message) {
+        return [message[@"keymap"] isEqualToString:@"ios"] &&
+               [message[@"type"] isEqualToString:@"keydown"] &&
+               [message[@"keyCode"] isEqualToNumber:[NSNumber numberWithInt:4]] &&
+               [message[@"modifiers"] isEqualToNumber:[NSNumber numberWithInt:131072]] &&
+               [message[@"characters"] isEqualToString:@"a"] &&
+               [message[@"charactersIgnoringModifiers"] isEqualToString:@"A"];
+      }]]);
+
+  // Clean up mocks
+  [engine stopMocking];
+  [keyEventChannel stopMocking];
+}
+
+- (void)testValidKeyDownEvent API_AVAILABLE(ios(13.4)) {
+  if (@available(iOS 13.4, *)) {
+    // noop
+  } else {
+    return;
+  }
+
+  id engine = OCMClassMock([FlutterEngine class]);
+
+  id keyEventChannel = OCMClassMock([FlutterBasicMessageChannel class]);
+  OCMStub([engine keyEventChannel]).andReturn(keyEventChannel);
+
+  FlutterViewController* vc = [[FlutterViewController alloc] initWithEngine:engine
+                                                                    nibName:nil
+                                                                     bundle:nil];
+
+  id testSet = [self fakeUiPressSetForPhase:UIPressPhaseEnded
+                                    keyCode:UIKeyboardHIDUsageKeyboardA
+                              modifierFlags:UIKeyModifierShift
+                                 characters:@"a"
+                charactersIgnoringModifiers:@"A"];
+
+  // Exercise behavior under test.
+  [vc dispatchPresses:testSet];
+
+  // Verify behavior.
+  OCMVerify([keyEventChannel
+      sendMessage:[OCMArg checkWithBlock:^BOOL(id message) {
+        return [message[@"keymap"] isEqualToString:@"ios"] &&
+               [message[@"type"] isEqualToString:@"keyup"] &&
+               [message[@"keyCode"] isEqualToNumber:[NSNumber numberWithInt:4]] &&
+               [message[@"modifiers"] isEqualToNumber:[NSNumber numberWithInt:131072]] &&
+               [message[@"characters"] isEqualToString:@"a"] &&
+               [message[@"charactersIgnoringModifiers"] isEqualToString:@"A"];
+      }]]);
+
+  // Clean up mocks
+  [engine stopMocking];
+  [keyEventChannel stopMocking];
+}
+
+- (void)testIgnoredKeyEvents API_AVAILABLE(ios(13.4)) {
+  if (@available(iOS 13.4, *)) {
+    // noop
+  } else {
+    return;
+  }
+
+  id engine = OCMClassMock([FlutterEngine class]);
+
+  id keyEventChannel = OCMClassMock([FlutterBasicMessageChannel class]);
+  OCMStub([engine keyEventChannel]).andReturn(keyEventChannel);
+
+  FlutterViewController* vc = [[FlutterViewController alloc] initWithEngine:engine
+                                                                    nibName:nil
+                                                                     bundle:nil];
+
+  id emptySet = [NSSet set];
+  id ignoredSet = [self fakeUiPressSetForPhase:UIPressPhaseStationary
+                                       keyCode:UIKeyboardHIDUsageKeyboardA
+                                 modifierFlags:UIKeyModifierShift
+                                    characters:@"a"
+                   charactersIgnoringModifiers:@"A"];
+
+  id mockUiPress = OCMClassMock([UIPress class]);
+  OCMStub([mockUiPress phase]).andReturn(UIPressPhaseBegan);
+  id emptyKeySet = [NSSet setWithArray:@[ mockUiPress ]];
+  // Exercise behavior under test.
+  [vc dispatchPresses:emptySet];
+  [vc dispatchPresses:ignoredSet];
+  [vc dispatchPresses:emptyKeySet];
+
+  // Verify behavior.
+  OCMVerify(never(), [keyEventChannel sendMessage:[OCMArg any]]);
+
+  // Clean up mocks
+  [engine stopMocking];
+  [keyEventChannel stopMocking];
+}
+
+- (NSSet<UIPress*>*)fakeUiPressSetForPhase:(UIPressPhase)phase
+                                   keyCode:(UIKeyboardHIDUsage)keyCode
+                             modifierFlags:(UIKeyModifierFlags)modifierFlags
+                                characters:(NSString*)characters
+               charactersIgnoringModifiers:(NSString*)charactersIgnoringModifiers
+    API_AVAILABLE(ios(13.4)) {
+  if (@available(iOS 13.4, *)) {
+    // noop
+  } else {
+    return [NSSet set];
+  }
+  id mockUiPress = OCMClassMock([UIPress class]);
+  OCMStub([mockUiPress phase]).andReturn(phase);
+
+  id mockUiKey = OCMClassMock([UIKey class]);
+  OCMStub([mockUiKey keyCode]).andReturn(keyCode);
+  OCMStub([mockUiKey modifierFlags]).andReturn(modifierFlags);
+  OCMStub([mockUiKey characters]).andReturn(characters);
+  OCMStub([mockUiKey charactersIgnoringModifiers]).andReturn(charactersIgnoringModifiers);
+
+  OCMStub([mockUiPress key]).andReturn(mockUiKey);
+
+  return [NSSet setWithArray:@[ mockUiPress ]];
+}
+
 @end