Switched FlutterPlatformViewSemanticsContainer.semanticsObject to weak.

Author: gaaclarke

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

@@ -508,8 +508,12 @@ - (UIAccessibilityTraits)accessibilityTraits {
 
 @end
 
+@interface FlutterPlatformViewSemanticsContainer ()
+@property(nonatomic, assign) SemanticsObject* semanticsObject;
+@property(nonatomic, strong) UIView* platformView;
+@end
+
 @implementation FlutterPlatformViewSemanticsContainer {
-  SemanticsObject* _semanticsObject;
   UIView* _platformView;
 }
 
@@ -531,13 +535,22 @@ - (instancetype)initWithSemanticsObject:(SemanticsObject*)object {
     flutter::FlutterPlatformViewsController* controller =
         object.bridge->GetPlatformViewsController();
     if (controller) {
-      _platformView = [controller->GetPlatformViewByID(object.node.platformViewId) view];
+      _platformView = [[controller->GetPlatformViewByID(object.node.platformViewId) view] retain];
     }
-    self.accessibilityElements = @[ _semanticsObject, _platformView ];
   }
   return self;
 }
 
+- (void)dealloc {
+  [_platformView release];
+  _platformView = nil;
+  [super dealloc];
+}
+
+- (NSArray*)accessibilityElements {
+  return @[ _semanticsObject, _platformView ];
+}
+
 - (CGRect)accessibilityFrame {
   return _semanticsObject.accessibilityFrame;
 }

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

@@ -133,10 +133,6 @@
   NSMutableArray<NSNumber*>* doomed_uids = [NSMutableArray arrayWithArray:[objects_.get() allKeys]];
   if (root)
     VisitObjectsRecursivelyAndRemove(root, doomed_uids);
-
-  for (NSNumber* doomed_uid in doomed_uids) {
-    ((SemanticsObject*)objects_.get()[doomed_uid]).platformViewSemanticsContainer = nil;
-  }
   [objects_ removeObjectsForKeys:doomed_uids];
 
   layoutChanged = layoutChanged || [doomed_uids count] > 0;
@@ -247,9 +243,6 @@ static bool DidFlagChange(const flutter::SemanticsNode& oldNode,
 }
 
 void AccessibilityBridge::clearState() {
-  for (SemanticsObject* object in objects_.get().allValues) {
-    object.platformViewSemanticsContainer = nil;
-  }
   [objects_ removeAllObjects];
   previous_route_id_ = 0;
   previous_routes_.clear();

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

@@ -19,6 +19,14 @@ @interface MockPlatformView : UIView
 @end
 @implementation MockPlatformView
 
+- (instancetype)init {
+  self = [super init];
+  if (self) {
+    gMockPlatformView = self;
+  }
+  return self;
+}
+
 - (void)dealloc {
   gMockPlatformView = nil;
   [super dealloc];
@@ -34,9 +42,7 @@ @implementation MockFlutterPlatformView
 
 - (instancetype)init {
   if (self = [super init]) {
-    MockPlatformView* view = [[MockPlatformView new] autorelease];
-    gMockPlatformView = view;
-    self.view = view;
+    _view = [[MockPlatformView alloc] init];
   }
   return self;
 }
@@ -56,8 +62,7 @@ @implementation MockFlutterPlatformFactory
 - (NSObject<FlutterPlatformView>*)createWithFrame:(CGRect)frame
                                    viewIdentifier:(int64_t)viewId
                                         arguments:(id _Nullable)args {
-  MockFlutterPlatformView* platformView = [[MockFlutterPlatformView new] autorelease];
-  return platformView;
+  return [[[MockFlutterPlatformView alloc] init] autorelease];
 }
 
 @end
@@ -214,8 +219,6 @@ - (void)testSemanticsDeallocated {
                            arguments:@{@"id" : @2, @"viewType" : @"MockFlutterPlatformView"}],
         result);
 
-    XCTAssertNotNil(gMockPlatformView);
-
     auto bridge = std::make_unique<flutter::AccessibilityBridge>(
         /*view=*/mockFlutterView,
         /*platform_view=*/platform_view.get(),
@@ -229,6 +232,7 @@ - (void)testSemanticsDeallocated {
     nodes[kRootNodeId] = semantics_node;
     flutter::CustomAccessibilityActionUpdates actions;
     bridge->UpdateSemantics(/*nodes=*/nodes, /*actions=*/actions);
+    XCTAssertNotNil(gMockPlatformView);
     flutterPlatformViewsController->Reset();
   }
   XCTAssertNil(gMockPlatformView);