[macOS] Add platformview creation parameter support

shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController.h

@@ -17,13 +17,15 @@
 @interface FlutterPlatformViewController ()
 
 /**
- * Creates a platform view of viewType with viewId.
+ * Creates a platform view of viewType with viewId and arguments passed from
+ * the framework's creationParams constructor parameter.
  * FlutterResult is updated to contain nil for success or to contain
  * a FlutterError if there is an error.
  */
-- (void)onCreateWithViewID:(int64_t)viewId
-                  viewType:(nonnull NSString*)viewType
-                    result:(nonnull FlutterResult)result;
+- (void)onCreateWithViewIdentifier:(int64_t)viewId
+                          viewType:(nonnull NSString*)viewType
+                         arguments:(nullable id)args
+                            result:(nonnull FlutterResult)result;
 
 /**
  * Disposes the platform view with `viewId`.

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

@@ -25,9 +25,10 @@ - (instancetype)init {
   return self;
 }
 
-- (void)onCreateWithViewID:(int64_t)viewId
-                  viewType:(nonnull NSString*)viewType
-                    result:(nonnull FlutterResult)result {
+- (void)onCreateWithViewIdentifier:(int64_t)viewId
+                          viewType:(nonnull NSString*)viewType
+                         arguments:(nullable id)args
+                            result:(nonnull FlutterResult)result {
   if (_platformViews.count(viewId) != 0) {
     result([FlutterError errorWithCode:@"recreating_view"
                                message:@"trying to create an already created view"
@@ -52,7 +53,7 @@ - (void)onCreateWithViewID:(int64_t)viewId
     return;
   }
 
-  NSView* platform_view = [factory createWithViewIdentifier:viewId arguments:nil];
+  NSView* platform_view = [factory createWithViewIdentifier:viewId arguments:args];
   // Flutter compositing requires CALayer-backed platform views.
   // Force the platform view to be backed by a CALayer.
   [platform_view setWantsLayer:YES];
@@ -92,7 +93,20 @@ - (void)handleMethodCall:(nonnull FlutterMethodCall*)call result:(nonnull Flutte
     if ([args objectForKey:@"id"]) {
       int64_t viewId = [args[@"id"] longLongValue];
       NSString* viewType = [NSString stringWithUTF8String:([args[@"viewType"] UTF8String])];
-      [self onCreateWithViewID:viewId viewType:viewType result:result];
+
+      id creationArgs = nil;
+      NSObject<FlutterPlatformViewFactory>* factory = _platformViewFactories[viewType];
+      if ([factory respondsToSelector:@selector(createArgsCodec)]) {
+        NSObject<FlutterMessageCodec>* codec = [factory createArgsCodec];
+        if (codec != nil && args[@"params"] != nil) {
+          FlutterStandardTypedData* creationArgsData = args[@"params"];
+          creationArgs = [codec decode:creationArgsData.data];
+        }
+      }
+      [self onCreateWithViewIdentifier:viewId
+                              viewType:viewType
+                             arguments:creationArgs
+                                result:result];
     } else {
       result([FlutterError errorWithCode:@"unknown_view"
                                  message:@"'id' argument must be passed to create a platform view."

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

@@ -43,11 +43,22 @@
 
   [platformViewController registerViewFactory:factory withId:@"MockPlatformView"];
 
+  NSDictionary* creationArgs = @{
+    @"album" : @"スコットとリバース",
+    @"releaseYear" : @2013,
+    @"artists" : @[ @"Scott Murphy", @"Rivers Cuomo" ],
+    @"playlist" : @[ @"おかしいやつ", @"ほどけていたんだ" ],
+  };
+  NSObject<FlutterMessageCodec>* codec = [factory createArgsCodec];
+  FlutterStandardTypedData* creationArgsData =
+      [FlutterStandardTypedData typedDataWithBytes:[codec encode:creationArgs]];
+
   FlutterMethodCall* methodCall =
       [FlutterMethodCall methodCallWithMethodName:@"create"
                                         arguments:@{
                                           @"id" : @2,
-                                          @"viewType" : @"MockPlatformView"
+                                          @"viewType" : @"MockPlatformView",
+                                          @"params" : creationArgsData,
                                         }];
 
   __block bool success = false;
@@ -58,8 +69,33 @@
     }
   };
   [platformViewController handleMethodCall:methodCall result:result];
-
   EXPECT_TRUE(success);
+
+  // Verify PlatformView parameters are decoded correctly.
+  TestFlutterPlatformView* view =
+      (TestFlutterPlatformView*)[platformViewController platformViewWithID:2];
+  ASSERT_TRUE(view != nil);
+  ASSERT_TRUE(view.args != nil);
+
+  // Verify string type.
+  NSString* album = [view.args objectForKey:@"album"];
+  EXPECT_TRUE([album isEqualToString:@"スコットとリバース"]);
+
+  // Verify int type.
+  NSNumber* releaseYear = [view.args objectForKey:@"releaseYear"];
+  EXPECT_EQ(releaseYear.intValue, 2013);
+
+  // Verify list/array types.
+  NSArray* artists = [view.args objectForKey:@"artists"];
+  ASSERT_TRUE(artists != nil);
+  ASSERT_EQ(artists.count, 2ul);
+  EXPECT_TRUE([artists[0] isEqualToString:@"Scott Murphy"]);
+  EXPECT_TRUE([artists[1] isEqualToString:@"Rivers Cuomo"]);
+
+  NSArray* playlist = [view.args objectForKey:@"playlist"];
+  ASSERT_EQ(playlist.count, 2ul);
+  EXPECT_TRUE([playlist[0] isEqualToString:@"おかしいやつ"]);
+  EXPECT_TRUE([playlist[1] isEqualToString:@"ほどけていたんだ"]);
 }
 
 TEST(FlutterPlatformViewController, TestCreateAndDispose) {

shell/platform/darwin/macos/framework/Source/TestFlutterPlatformView.h

@@ -7,6 +7,10 @@
 #import "flutter/shell/platform/darwin/macos/framework/Headers/FlutterEngine.h"
 
 @interface TestFlutterPlatformView : NSView
+
+/// Arguments passed via the params value in the create method call.
+@property(nonatomic, copy) id args;
+
 @end
 
 @interface TestFlutterPlatformViewFactory : NSObject <FlutterPlatformViewFactory>

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

@@ -9,16 +9,17 @@
 
 @implementation TestFlutterPlatformView
 
-- (instancetype)initWithFrame:(CGRect)frame {
+- (instancetype)initWithFrame:(CGRect)frame arguments:(nullable NSDictionary*)args {
   self = [super initWithFrame:frame];
+  _args = args;
   return self;
 }
 
 @end
 
 @implementation TestFlutterPlatformViewFactory
 - (NSView*)createWithViewIdentifier:(int64_t)viewId arguments:(nullable id)args {
-  return [[TestFlutterPlatformView alloc] initWithFrame:CGRectZero];
+  return [[TestFlutterPlatformView alloc] initWithFrame:CGRectZero arguments:args];
 }
 
 - (NSObject<FlutterMessageCodec>*)createArgsCodec {