finish nsobject

packages/webview_flutter/webview_flutter_wkwebview/ios/Classes/FWFDataConverters.h

@@ -130,4 +130,13 @@ extern WKNavigationActionPolicy FWFWKNavigationActionPolicyFromEnumData(FWFWKNav
  */
 extern FWFNSErrorData *FWFNSErrorDataFromNSError(NSError *error);
 
+/**
+ * Converts an NSKeyValueChangeKey to a FWFNSKeyValueChangeKeyEnumData.
+ *
+ * @param key The data object containing information to create a FWFNSKeyValueChangeKeyEnumData.
+ *
+ * @return A FWFNSKeyValueChangeKeyEnumData or nil if data could not be converted.
+ */
+extern FWFNSKeyValueChangeKeyEnumData *FWFNSKeyValueChangeKeyEnumDataFromNSKeyValueChangeKey(NSKeyValueChangeKey key);
+
 NS_ASSUME_NONNULL_END

packages/webview_flutter/webview_flutter_wkwebview/ios/Classes/FWFDataConverters.m

@@ -181,3 +181,23 @@ WKNavigationActionPolicy FWFWKNavigationActionPolicyFromEnumData(FWFWKNavigation
 FWFNSErrorData *FWFNSErrorDataFromNSError(NSError *error) {
   return [FWFNSErrorData makeWithCode:@(error.code) domain:error.domain localiziedDescription:error.localizedDescription];
 }
+
+FWFNSKeyValueChangeKeyEnumData *FWFNSKeyValueChangeKeyEnumDataFromNSKeyValueChangeKey(NSKeyValueChangeKey key) {
+  if ([key isEqualToString:NSKeyValueChangeIndexesKey]) {
+    return [FWFNSKeyValueChangeKeyEnumData makeWithValue:FWFNSKeyValueChangeKeyEnumIndexes];
+  } else
+  if ([key isEqualToString:NSKeyValueChangeKindKey]) {
+    return [FWFNSKeyValueChangeKeyEnumData makeWithValue:FWFNSKeyValueChangeKeyEnumKind];
+  }else
+  if ([key isEqualToString:NSKeyValueChangeNewKey]) {
+    return [FWFNSKeyValueChangeKeyEnumData makeWithValue:FWFNSKeyValueChangeKeyEnumNewValue];
+  }else
+  if ([key isEqualToString:NSKeyValueChangeNotificationIsPriorKey]) {
+    return [FWFNSKeyValueChangeKeyEnumData makeWithValue:FWFNSKeyValueChangeKeyEnumNotificationIsPrior];
+  }else
+  if ([key isEqualToString:NSKeyValueChangeOldKey]) {
+    return [FWFNSKeyValueChangeKeyEnumData makeWithValue:FWFNSKeyValueChangeKeyEnumOldValue];
+  }
+
+  return nil;
+}

packages/webview_flutter/webview_flutter_wkwebview/ios/Classes/FWFObjectHostApi.m

@@ -19,6 +19,31 @@ - (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessen
   }
   return self;
 }
+
+- (long)identifierForObject:(NSObject *)instance {
+  return [self.instanceManager identifierWithStrongReferenceForInstance:instance];
+}
+
+- (void)observeValueForObject:(NSObject *)instance
+                      keyPath:(NSString *)keyPath
+                       object:(NSObject *)object
+                       change:(NSDictionary<NSKeyValueChangeKey, id> *)change
+                   completion:(void (^)(NSError * _Nullable))completion {
+  NSMutableArray<FWFNSKeyValueChangeKeyEnumData *> *changeKeys = [NSMutableArray array];
+  NSMutableArray<id> *changeValues = [NSMutableArray array];
+
+  [change enumerateKeysAndObjectsUsingBlock:^(NSKeyValueChangeKey key, id value, BOOL* stop) {
+    [changeKeys addObject:FWFNSKeyValueChangeKeyEnumDataFromNSKeyValueChangeKey(key)];
+    [changeValues addObject:value];
+  }];
+
+  [self observeValueForObjectWithIdentifier:@([self identifierForObject:instance])
+                                    keyPath:keyPath
+                           objectIdentifier:@([self.instanceManager identifierWithStrongReferenceForInstance:object])
+                                 changeKeys:changeKeys
+                               changeValues:changeValues
+                                 completion:completion];
+}
 @end
 
 @implementation FWFObject
@@ -31,6 +56,12 @@ - (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessen
   }
   return self;
 }
+
+- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context {
+  [self.objectApi observeValueForObject:self keyPath:keyPath object:object change:change completion:^(NSError *error) {
+    NSAssert(!error, @"%@", error);
+  }];
+}
 @end
 
 @interface FWFObjectHostApiImpl ()