Access on/off labels settings for switches on iOS

Author: RtgrV

lib/ui/window.dart

@@ -771,6 +771,7 @@ class AccessibilityFeatures {
   static const int _kBoldTextIndex = 1 << 3;
   static const int _kReduceMotionIndex = 1 << 4;
   static const int _kHighContrastIndex = 1 << 5;
+  static const int _kOnOffSwitchLabelsIndex = 1 << 6;
 
   // A bitfield which represents each enabled feature.
   final int _index;
@@ -803,6 +804,11 @@ class AccessibilityFeatures {
   /// Only supported on iOS.
   bool get highContrast => _kHighContrastIndex & _index != 0;
 
+  /// The platform is requesting to show on/off labels inside switches.
+  ///
+  /// Only supported on iOS.
+  bool get onOffSwitchLabels => _kOnOffSwitchLabelsIndex & _index != 0;
+
   @override
   String toString() {
     final List<String> features = <String>[];
@@ -818,6 +824,8 @@ class AccessibilityFeatures {
       features.add('reduceMotion');
     if (highContrast)
       features.add('highContrast');
+    if (onOffSwitchLabels)
+      features.add('onOffSwitchLabels');
     return 'AccessibilityFeatures$features';
   }
 

lib/ui/window/platform_configuration.h

@@ -35,6 +35,7 @@ enum class AccessibilityFeatureFlag : int32_t {
   kBoldText = 1 << 3,
   kReduceMotion = 1 << 4,
   kHighContrast = 1 << 5,
+  kOnOffSwitchLabels = 1 << 6,
 };
 
 //--------------------------------------------------------------------------

lib/web_ui/lib/window.dart

@@ -148,6 +148,7 @@ class AccessibilityFeatures {
   static const int _kBoldTextIndex = 1 << 3;
   static const int _kReduceMotionIndex = 1 << 4;
   static const int _kHighContrastIndex = 1 << 5;
+  static const int _kOnOffSwitchLabelsIndex = 1 << 6;
 
   // A bitfield which represents each enabled feature.
   final int _index;
@@ -158,6 +159,7 @@ class AccessibilityFeatures {
   bool get boldText => _kBoldTextIndex & _index != 0;
   bool get reduceMotion => _kReduceMotionIndex & _index != 0;
   bool get highContrast => _kHighContrastIndex & _index != 0;
+  bool get onOffSwitchLabels => _kOnOffSwitchLabelsIndex & _index != 0;
 
   @override
   String toString() {
@@ -180,6 +182,9 @@ class AccessibilityFeatures {
     if (highContrast) {
       features.add('highContrast');
     }
+    if (onOffSwitchLabels) {
+      features.add('onOffSwitchLabels');
+    }
     return 'AccessibilityFeatures$features';
   }
 

shell/platform/darwin/ios/BUILD.gn

@@ -96,6 +96,8 @@ source_set("flutter_framework_source") {
     "framework/Source/accessibility_bridge.mm",
     "framework/Source/accessibility_text_entry.h",
     "framework/Source/accessibility_text_entry.mm",
+    "framework/Source/accessibility_value_provider.h",
+    "framework/Source/accessibility_value_provider.mm",
     "framework/Source/connection_collection.h",
     "framework/Source/connection_collection.mm",
     "framework/Source/platform_message_response_darwin.h",

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

@@ -331,6 +331,13 @@ - (void)setupNotificationCenterObservers {
                  name:UIAccessibilityDarkerSystemColorsStatusDidChangeNotification
                object:nil];
 
+  if (@available(iOS 13.0, *)) {
+    [center addObserver:self
+               selector:@selector(onAccessibilityStatusChanged:)
+                   name:UIAccessibilityOnOffSwitchLabelsDidChangeNotification
+                 object:nil];
+  }
+
   [center addObserver:self
              selector:@selector(onUserSettingsChanged:)
                  name:UIContentSizeCategoryDidChangeNotification
@@ -1417,19 +1424,7 @@ - (void)onAccessibilityStatusChanged:(NSNotification*)notification {
     return;
   }
   auto platformView = [_engine.get() platformView];
-  int32_t flags = 0;
-  if (UIAccessibilityIsInvertColorsEnabled()) {
-    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kInvertColors);
-  }
-  if (UIAccessibilityIsReduceMotionEnabled()) {
-    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kReduceMotion);
-  }
-  if (UIAccessibilityIsBoldTextEnabled()) {
-    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kBoldText);
-  }
-  if (UIAccessibilityDarkerSystemColorsEnabled()) {
-    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kHighContrast);
-  }
+  int32_t flags = [self accessibilityFlags];
 #if TARGET_OS_SIMULATOR
   // There doesn't appear to be any way to determine whether the accessibility
   // inspector is enabled on the simulator. We conservatively always turn on the
@@ -1447,6 +1442,27 @@ - (void)onAccessibilityStatusChanged:(NSNotification*)notification {
 #endif
 }
 
+- (int32_t)accessibilityFlags {
+  int32_t flags = 0;
+  if (UIAccessibilityIsInvertColorsEnabled()) {
+    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kInvertColors);
+  }
+  if (UIAccessibilityIsReduceMotionEnabled()) {
+    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kReduceMotion);
+  }
+  if (UIAccessibilityIsBoldTextEnabled()) {
+    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kBoldText);
+  }
+  if (UIAccessibilityDarkerSystemColorsEnabled()) {
+    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kHighContrast);
+  }
+  if ([AccessibilityValueProvider accessibilityIsOnOffSwitchLabelsEnabled]) {
+    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kOnOffSwitchLabels);
+  }
+
+  return flags;
+}
+
 #pragma mark - Set user settings
 
 - (void)traitCollectionDidChange:(UITraitCollection*)previousTraitCollection {

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

@@ -14,6 +14,7 @@
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterFakeKeyEvents.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h"
+#import "flutter/shell/platform/darwin/ios/framework/Source/accessibility_value_provider.h"
 #import "flutter/shell/platform/embedder/embedder.h"
 
 FLUTTER_ASSERT_ARC
@@ -627,6 +628,48 @@ - (void)testItReportsHighContrastWhenTraitCollectionRequestsIt {
   [mockTraitCollection stopMocking];
 }
 
+- (void)testItReportsNoAccessibilityFlagsSet {
+  if (@available(iOS 13, *)) {
+    // noop
+  } else {
+    return;
+  }
+
+  // Setup test.
+  FlutterViewController* viewController =
+      [[FlutterViewController alloc] initWithEngine:self.mockEngine nibName:nil bundle:nil];
+
+  id valueProvider = OCMClassMock([AccessibilityValueProvider class]);
+  OCMStub([valueProvider accessibilityIsOnOffSwitchLabelsEnabled]).andReturn(false);
+
+  // Exercise behavior under test.
+  int32_t flags = [viewController accessibilityFlags];
+
+  // Verify behavior.
+  XCTAssert(flags == 0);
+}
+
+- (void)testItReportsAccessibilityOnOffSwitchLabelsFlagSet {
+  if (@available(iOS 13, *)) {
+    // noop
+  } else {
+    return;
+  }
+
+  // Setup test.
+  FlutterViewController* viewController =
+      [[FlutterViewController alloc] initWithEngine:self.mockEngine nibName:nil bundle:nil];
+
+  id valueProvider = OCMClassMock([AccessibilityValueProvider class]);
+  OCMStub([valueProvider accessibilityIsOnOffSwitchLabelsEnabled]).andReturn(true);
+
+  // Exercise behavior under test.
+  int32_t flags = [viewController accessibilityFlags];
+
+  // Verify behavior.
+  XCTAssert(flags == 1 << 6);
+}
+
 - (void)testPerformOrientationUpdateForcesOrientationChange {
   [self orientationTestWithOrientationUpdate:UIInterfaceOrientationMaskPortrait
                           currentOrientation:UIInterfaceOrientationLandscapeLeft

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

@@ -45,6 +45,7 @@ extern NSNotificationName const FlutterViewControllerShowHomeIndicator;
               nextAction:(void (^)())nextAction API_AVAILABLE(ios(13.4));
 - (void)addInternalPlugins;
 - (void)deregisterNotifications;
+- (int32_t)accessibilityFlags;
 @end
 
 #endif  // FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERVIEWCONTROLLER_INTERNAL_H_

shell/platform/darwin/ios/framework/Source/accessibility_value_provider.h

@@ -0,0 +1,18 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_ACCESSIBILITY_VALUE_PROVIDER_H_
+#define SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_ACCESSIBILITY_VALUE_PROVIDER_H_
+
+/**
+ * An accessibility value provider used to provide accessibility setting values from UIKit.
+ * To make the behavior testable.
+ */
+@interface AccessibilityValueProvider : NSObject
+
++ (BOOL)accessibilityIsOnOffSwitchLabelsEnabled;
+
+@end
+
+#endif  // SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_ACCESSIBILITY_VALUE_PROVIDER_H_

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

@@ -0,0 +1,20 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <UIKit/UIKit.h>
+
+#import "flutter/shell/platform/darwin/ios/framework/Source/accessibility_value_provider.h"
+
+@implementation AccessibilityValueProvider {
+}
+
++ (BOOL)accessibilityIsOnOffSwitchLabelsEnabled {
+  if (@available(iOS 13, *)) {
+    return UIAccessibilityIsOnOffSwitchLabelsEnabled();
+  } else {
+    return NO;
+  }
+}
+
+@end