added a test that exercises announcing route changes

Author: gaaclarke

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

@@ -36,9 +36,18 @@ class PlatformViewIOS;
  */
 class AccessibilityBridge final : public AccessibilityBridgeIos {
  public:
+  /** Delegate for handling iOS operations. */
+  class IosDelegate {
+   public:
+    virtual ~IosDelegate() = default;
+    virtual void PostAccessibilityNotification(UIAccessibilityNotifications notification,
+                                               id argument) = 0;
+  };
+
   AccessibilityBridge(UIView* view,
                       PlatformViewIOS* platform_view,
-                      FlutterPlatformViewsController* platform_views_controller);
+                      FlutterPlatformViewsController* platform_views_controller,
+                      std::unique_ptr<IosDelegate> ios_delegate = nullptr);
   ~AccessibilityBridge();
 
   void UpdateSemantics(flutter::SemanticsNodeUpdates nodes,
@@ -75,6 +84,7 @@ class AccessibilityBridge final : public AccessibilityBridgeIos {
   int32_t previous_route_id_;
   std::unordered_map<int32_t, flutter::CustomAccessibilityAction> actions_;
   std::vector<int32_t> previous_routes_;
+  std::unique_ptr<IosDelegate> ios_delegate_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(AccessibilityBridge);
 };

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

@@ -13,17 +13,29 @@
 FLUTTER_ASSERT_NOT_ARC
 
 namespace flutter {
+namespace {
+class DefaultIosDelegate : public AccessibilityBridge::IosDelegate {
+ public:
+  void PostAccessibilityNotification(UIAccessibilityNotifications notification,
+                                     id argument) override {
+    UIAccessibilityPostNotification(notification, argument);
+  }
+};
+}  // namespace
 
 AccessibilityBridge::AccessibilityBridge(UIView* view,
                                          PlatformViewIOS* platform_view,
-                                         FlutterPlatformViewsController* platform_views_controller)
+                                         FlutterPlatformViewsController* platform_views_controller,
+                                         std::unique_ptr<IosDelegate> ios_delegate)
     : view_(view),
       platform_view_(platform_view),
       platform_views_controller_(platform_views_controller),
       objects_([[NSMutableDictionary alloc] init]),
       weak_factory_(this),
       previous_route_id_(0),
-      previous_routes_({}) {
+      previous_routes_({}),
+      ios_delegate_(ios_delegate ? std::move(ios_delegate)
+                                 : std::make_unique<DefaultIosDelegate>()) {
   accessibility_channel_.reset([[FlutterBasicMessageChannel alloc]
          initWithName:@"flutter/accessibility"
       binaryMessenger:platform_view->GetOwnerViewController().get().engine.binaryMessenger
@@ -138,14 +150,15 @@
   layoutChanged = layoutChanged || [doomed_uids count] > 0;
   if (routeChanged) {
     NSString* routeName = [lastAdded routeName];
-    UIAccessibilityPostNotification(UIAccessibilityScreenChangedNotification, routeName);
+    ios_delegate_->PostAccessibilityNotification(UIAccessibilityScreenChangedNotification,
+                                                 routeName);
   } else if (layoutChanged) {
     // TODO(goderbauer): figure out which node to focus next.
-    UIAccessibilityPostNotification(UIAccessibilityLayoutChangedNotification, nil);
+    ios_delegate_->PostAccessibilityNotification(UIAccessibilityLayoutChangedNotification, nil);
   }
   if (scrollOccured) {
     // TODO(tvolkert): provide meaningful string (e.g. "page 2 of 5")
-    UIAccessibilityPostNotification(UIAccessibilityPageScrolledNotification, @"");
+    ios_delegate_->PostAccessibilityNotification(UIAccessibilityPageScrolledNotification, @"");
   }
 }
 
@@ -233,7 +246,7 @@ static bool DidFlagChange(const flutter::SemanticsNode& oldNode,
   NSString* type = annotatedEvent[@"type"];
   if ([type isEqualToString:@"announce"]) {
     NSString* message = annotatedEvent[@"data"][@"message"];
-    UIAccessibilityPostNotification(UIAccessibilityAnnouncementNotification, message);
+    ios_delegate_->PostAccessibilityNotification(UIAccessibilityAnnouncementNotification, message);
   }
 }
 

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

@@ -86,6 +86,17 @@ void OnPlatformViewRegisterTexture(std::shared_ptr<Texture> texture) override {}
   void OnPlatformViewUnregisterTexture(int64_t texture_id) override {}
   void OnPlatformViewMarkTextureFrameAvailable(int64_t texture_id) override {}
 };
+
+class MockIosDelegate : public AccessibilityBridge::IosDelegate {
+ public:
+  void PostAccessibilityNotification(UIAccessibilityNotifications notification,
+                                     id argument) override {
+    if (on_PostAccessibilityNotification_) {
+      on_PostAccessibilityNotification_(notification, argument);
+    }
+  }
+  std::function<void(UIAccessibilityNotifications, id)> on_PostAccessibilityNotification_;
+};
 }  // namespace
 }  // namespace flutter
 
@@ -238,4 +249,59 @@ - (void)testSemanticsDeallocated {
   XCTAssertNil(gMockPlatformView);
 }
 
+- (void)testAnnouncesRouteChanges {
+  flutter::MockDelegate mock_delegate;
+  auto thread_task_runner = CreateNewThread("AccessibilityBridgeTest");
+  flutter::TaskRunners runners(/*label=*/self.name.UTF8String,
+                               /*platform=*/thread_task_runner,
+                               /*raster=*/thread_task_runner,
+                               /*ui=*/thread_task_runner,
+                               /*io=*/thread_task_runner);
+  auto platform_view = std::make_unique<flutter::PlatformViewIOS>(
+      /*delegate=*/mock_delegate,
+      /*rendering_api=*/flutter::IOSRenderingAPI::kSoftware,
+      /*task_runners=*/runners);
+  id mockFlutterView = OCMClassMock([FlutterView class]);
+  std::string label = "some label";
+
+  NSMutableArray<NSDictionary<NSString*, id>*>* accessibility_notifications =
+      [[[NSMutableArray alloc] init] autorelease];
+  auto ios_delegate = std::make_unique<flutter::MockIosDelegate>();
+  ios_delegate->on_PostAccessibilityNotification_ =
+      [accessibility_notifications](UIAccessibilityNotifications notification, id argument) {
+        [accessibility_notifications addObject:@{
+          @"notification" : @(notification),
+          @"argument" : argument ? argument : [NSNull null],
+        }];
+      };
+  __block auto bridge =
+      std::make_unique<flutter::AccessibilityBridge>(/*view=*/mockFlutterView,
+                                                     /*platform_view=*/platform_view.get(),
+                                                     /*platform_views_controller=*/nil,
+                                                     /*ios_delegate=*/std::move(ios_delegate));
+
+  flutter::CustomAccessibilityActionUpdates actions;
+  flutter::SemanticsNodeUpdates nodes;
+
+  flutter::SemanticsNode route_node;
+  route_node.id = 1;
+  route_node.label = label;
+  route_node.flags = static_cast<int32_t>(flutter::SemanticsFlags::kScopesRoute) |
+                     static_cast<int32_t>(flutter::SemanticsFlags::kNamesRoute);
+  route_node.label = "route";
+  nodes[route_node.id] = route_node;
+  flutter::SemanticsNode root_node;
+  root_node.id = kRootNodeId;
+  root_node.label = label;
+  root_node.childrenInTraversalOrder = {1};
+  root_node.childrenInHitTestOrder = {1};
+  nodes[root_node.id] = root_node;
+  bridge->UpdateSemantics(/*nodes=*/nodes, /*actions=*/actions);
+
+  XCTAssertEqual([accessibility_notifications count], 1ul);
+  XCTAssertEqualObjects(accessibility_notifications[0][@"argument"], @"route");
+  XCTAssertEqual([accessibility_notifications[0][@"notification"] unsignedIntValue],
+                 UIAccessibilityScreenChangedNotification);
+}
+
 @end