[macOS] Set textfield autofill type

macOS supports three autofill types: username, password, and
oneTimeCode. Apply these content types when the equivalent Flutter
autofill hints are set.

Note that enabling autocomplete of username and password in applications
will still require setting the "Autofill Credential Provider" and
"Associated Domains" entitlements, and for the FlutterTextInputPlugin to
be updated to use an NSSecureTextInput input type.

Issue: flutter/flutter#120252

Author: cbracken

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

@@ -91,11 +91,34 @@ typedef NS_ENUM(NSUInteger, FlutterTextAffinity) {
 }
 
 // Returns the autofill hint content type, if specified; otherwise nil.
-static NSString* GetAutofillContentType(NSDictionary* autofill) {
+static NSString* GetAutofillHint(NSDictionary* autofill) {
   NSArray<NSString*>* hints = autofill[kAutofillHints];
   return hints.count > 0 ? hints[0] : nil;
 }
 
+static NSTextContentType GetTextContentType(NSDictionary* configuration)
+    API_AVAILABLE(macos(11.0)) {
+  // Check autofill hints.
+  NSDictionary* autofill = configuration[kAutofillProperties];
+  if (autofill) {
+    NSString* hint = GetAutofillHint(autofill);
+    if ([hint isEqualToString:@"username"]) {
+      return NSTextContentTypeUsername;
+    }
+    if ([hint isEqualToString:@"password"]) {
+      return NSTextContentTypePassword;
+    }
+    if ([hint isEqualToString:@"oneTimeCode"]) {
+      return NSTextContentTypeOneTimeCode;
+    }
+  }
+  // If no autofill hints, guess based on other attributes.
+  if ([configuration[kSecureTextEntry] boolValue]) {
+    return NSTextContentTypePassword;
+  }
+  return nil;
+}
+
 // Returns YES if configuration describes a field for which autocomplete should be enabled for
 // the specified TextInputConfiguration. Autocomplete is enabled by default, but will be disabled
 // if the field is password-related, or if the configuration contains no autofill settings.
@@ -113,8 +136,8 @@ static BOOL EnableAutocompleteForTextInputConfiguration(NSDictionary* configurat
 
   // Disable if autofill properties indicate a username/password.
   // See: https://github.com/flutter/flutter/issues/119824
-  NSString* contentType = GetAutofillContentType(autofill);
-  if ([contentType isEqualToString:@"password"] || [contentType isEqualToString:@"username"]) {
+  NSString* hint = GetAutofillHint(autofill);
+  if ([hint isEqualToString:@"password"] || [hint isEqualToString:@"username"]) {
     return NO;
   }
   return YES;
@@ -386,7 +409,9 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
       _inputType = inputTypeInfo[kTextInputTypeName];
       self.textAffinity = kFlutterTextAffinityUpstream;
       self.automaticTextCompletionEnabled = EnableAutocomplete(config);
-      // TODO(cbracken): support text content types https://github.com/flutter/flutter/issues/120252
+      if (@available(macOS 11.0, *)) {
+        self.contentType = GetTextContentType(config);
+      }
 
       _activeModel = std::make_unique<flutter::TextInputModel>();
     }

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

@@ -449,6 +449,12 @@ - (bool)testAutocompleteEnabledWhenAutofillSet {
 
   // Verify autocomplete is enabled.
   EXPECT_TRUE([plugin isAutomaticTextCompletionEnabled]);
+
+  // Verify content type is nil for unsupported content types.
+  if (@available(macOS 11.0, *)) {
+    EXPECT_EQ([plugin contentType], nil);
+  }
+
   return true;
 }
 
@@ -510,7 +516,6 @@ - (bool)testAutocompleteDisabledWhenObscureTextSet {
                                                   @"obscureText" : @YES,
                                                   @"autofill" : @{
                                                     @"uniqueIdentifier" : @"field1",
-                                                    @"hints" : @[ @"name" ],
                                                     @"editingValue" : @{@"text" : @""},
                                                   }
                                                 }
@@ -555,6 +560,11 @@ - (bool)testAutocompleteDisabledWhenPasswordAutofillSet {
 
   // Verify autocomplete is disabled.
   EXPECT_FALSE([plugin isAutomaticTextCompletionEnabled]);
+
+  // Verify content type is password.
+  if (@available(macOS 11.0, *)) {
+    EXPECT_EQ([plugin contentType], NSTextContentTypePassword);
+  }
   return true;
 }
 
@@ -608,6 +618,86 @@ - (bool)testAutocompleteDisabledWhenAutofillGroupIncludesPassword {
   return true;
 }
 
+- (bool)testContentTypeWhenAutofillTypeIsUsername {
+  // Set up FlutterTextInputPlugin.
+  id engineMock = flutter::testing::CreateMockFlutterEngine(@"");
+  id binaryMessengerMock = OCMProtocolMock(@protocol(FlutterBinaryMessenger));
+  OCMStub(  // NOLINT(google-objc-avoid-throwing-exception)
+      [engineMock binaryMessenger])
+      .andReturn(binaryMessengerMock);
+  FlutterViewController* viewController = [[FlutterViewController alloc] initWithEngine:engineMock
+                                                                                nibName:@""
+                                                                                 bundle:nil];
+  FlutterTextInputPlugin* plugin =
+      [[FlutterTextInputPlugin alloc] initWithViewController:viewController];
+
+  // Set input client 1.
+  [plugin handleMethodCall:[FlutterMethodCall
+                               methodCallWithMethodName:@"TextInput.setClient"
+                                              arguments:@[
+                                                @(1), @{
+                                                  @"inputAction" : @"action",
+                                                  @"inputType" : @{@"name" : @"inputName"},
+                                                  @"autofill" : @{
+                                                    @"uniqueIdentifier" : @"field1",
+                                                    @"hints" : @[ @"username" ],
+                                                    @"editingValue" : @{@"text" : @""},
+                                                  }
+                                                }
+                                              ]]
+                    result:^(id){
+                    }];
+
+  // Verify autocomplete is disabled.
+  EXPECT_FALSE([plugin isAutomaticTextCompletionEnabled]);
+
+  // Verify content type is username.
+  if (@available(macOS 11.0, *)) {
+    EXPECT_EQ([plugin contentType], NSTextContentTypeUsername);
+  }
+  return true;
+}
+
+- (bool)testContentTypeWhenAutofillTypeIsOneTimeCode {
+  // Set up FlutterTextInputPlugin.
+  id engineMock = flutter::testing::CreateMockFlutterEngine(@"");
+  id binaryMessengerMock = OCMProtocolMock(@protocol(FlutterBinaryMessenger));
+  OCMStub(  // NOLINT(google-objc-avoid-throwing-exception)
+      [engineMock binaryMessenger])
+      .andReturn(binaryMessengerMock);
+  FlutterViewController* viewController = [[FlutterViewController alloc] initWithEngine:engineMock
+                                                                                nibName:@""
+                                                                                 bundle:nil];
+  FlutterTextInputPlugin* plugin =
+      [[FlutterTextInputPlugin alloc] initWithViewController:viewController];
+
+  // Set input client 1.
+  [plugin handleMethodCall:[FlutterMethodCall
+                               methodCallWithMethodName:@"TextInput.setClient"
+                                              arguments:@[
+                                                @(1), @{
+                                                  @"inputAction" : @"action",
+                                                  @"inputType" : @{@"name" : @"inputName"},
+                                                  @"autofill" : @{
+                                                    @"uniqueIdentifier" : @"field1",
+                                                    @"hints" : @[ @"oneTimeCode" ],
+                                                    @"editingValue" : @{@"text" : @""},
+                                                  }
+                                                }
+                                              ]]
+                    result:^(id){
+                    }];
+
+  // Verify autocomplete is disabled.
+  EXPECT_FALSE([plugin isAutomaticTextCompletionEnabled]);
+
+  // Verify content type is username.
+  if (@available(macOS 11.0, *)) {
+    EXPECT_EQ([plugin contentType], NSTextContentTypeOneTimeCode);
+  }
+  return true;
+}
+
 - (bool)testFirstRectForCharacterRange {
   id engineMock = flutter::testing::CreateMockFlutterEngine(@"");
   id binaryMessengerMock = OCMProtocolMock(@protocol(FlutterBinaryMessenger));