move ViewTransition APIs not for react reconciler to its own TurboModule

Summary:
## Changelog:

[General] [Changed] - move ViewTransition APIs not for react reconciler to its own TurboModule

Move `unstable_getViewTransitionInstance` which is not consumed by react reconciler out of UIManagerBinding into a standalone NativeViewTransition CxxTurboModule, following the NativeDOM pattern. This avoids bloating UIManager with ViewTransition-specific APIs.

Reviewed By: christophpurrer

Differential Revision: D98360009

Author: zeyap

packages/react-native/Libraries/ReactNative/FabricUIManager.js

@@ -97,16 +97,6 @@ export interface Spec {
   +unstable_ContinuousEventPriority: number;
   +unstable_IdleEventPriority: number;
   +unstable_getCurrentEventPriority: () => number;
-  +unstable_getViewTransitionInstance: (
-    name: string,
-    pseudo: string,
-  ) => ?{
-    x: number,
-    y: number,
-    width: number,
-    height: number,
-    nativeTag: number,
-  };
 }
 
 let nativeFabricUIManagerProxy: ?Spec;
@@ -139,7 +129,6 @@ const CACHED_PROPERTIES = [
   'unstable_ContinuousEventPriority',
   'unstable_IdleEventPriority',
   'unstable_getCurrentEventPriority',
-  'unstable_getViewTransitionInstance',
 ];
 
 // This is exposed as a getter because apps using the legacy renderer AND

packages/react-native/ReactCommon/react/nativemodule/defaults/DefaultTurboModules.cpp

@@ -13,6 +13,7 @@
 #include <react/nativemodule/intersectionobserver/NativeIntersectionObserver.h>
 #include <react/nativemodule/microtasks/NativeMicrotasks.h>
 #include <react/nativemodule/mutationobserver/NativeMutationObserver.h>
+#include <react/nativemodule/viewtransition/NativeViewTransition.h>
 #include <react/nativemodule/webperformance/NativePerformance.h>
 #include <react/renderer/animated/AnimatedModule.h>
 
@@ -57,6 +58,12 @@ namespace facebook::react {
     }
   }
 
+  if (ReactNativeFeatureFlags::viewTransitionEnabled()) {
+    if (name == NativeViewTransition::kModuleName) {
+      return std::make_shared<NativeViewTransition>(jsInvoker);
+    }
+  }
+
   if (ReactNativeFeatureFlags::cxxNativeAnimatedEnabled() &&
       ReactNativeFeatureFlags::useSharedAnimatedBackend() &&
       name == AnimatedModule::kModuleName) {

packages/react-native/ReactCommon/react/nativemodule/viewtransition/NativeViewTransition.cpp

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "NativeViewTransition.h"
+
+#include <react/renderer/uimanager/UIManagerBinding.h>
+
+#ifdef RN_DISABLE_OSS_PLUGIN_HEADER
+#include "Plugins.h"
+#endif
+
+std::shared_ptr<facebook::react::TurboModule>
+NativeViewTransitionModuleProvider(
+    std::shared_ptr<facebook::react::CallInvoker> jsInvoker) {
+  return std::make_shared<facebook::react::NativeViewTransition>(
+      std::move(jsInvoker));
+}
+
+namespace facebook::react {
+
+namespace {
+UIManager& getUIManagerFromRuntime(jsi::Runtime& runtime) {
+  return UIManagerBinding::getBinding(runtime)->getUIManager();
+}
+} // namespace
+
+NativeViewTransition::NativeViewTransition(
+    std::shared_ptr<CallInvoker> jsInvoker)
+    : NativeViewTransitionCxxSpec(std::move(jsInvoker)) {}
+
+std::optional<jsi::Object> NativeViewTransition::getViewTransitionInstance(
+    jsi::Runtime& rt,
+    const std::string& name,
+    const std::string& pseudo) {
+  auto& uiManager = getUIManagerFromRuntime(rt);
+  auto* viewTransitionDelegate = uiManager.getViewTransitionDelegate();
+  if (viewTransitionDelegate == nullptr) {
+    return std::nullopt;
+  }
+
+  auto instance =
+      viewTransitionDelegate->getViewTransitionInstance(name, pseudo);
+  if (!instance) {
+    return std::nullopt;
+  }
+
+  auto result = jsi::Object(rt);
+  result.setProperty(rt, "x", instance->x);
+  result.setProperty(rt, "y", instance->y);
+  result.setProperty(rt, "width", instance->width);
+  result.setProperty(rt, "height", instance->height);
+  result.setProperty(rt, "nativeTag", static_cast<double>(instance->nativeTag));
+  return result;
+}
+
+} // namespace facebook::react

packages/react-native/ReactCommon/react/nativemodule/viewtransition/NativeViewTransition.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <optional>
+#include <string>
+
+#if __has_include("FBReactNativeSpecJSI.h") // CocoaPod headers on Apple
+#include "FBReactNativeSpecJSI.h"
+#else
+#include <FBReactNativeSpec/FBReactNativeSpecJSI.h>
+#endif
+
+#include <react/renderer/bridging/bridging.h>
+
+namespace facebook::react {
+
+class NativeViewTransition : public NativeViewTransitionCxxSpec<NativeViewTransition> {
+ public:
+  explicit NativeViewTransition(std::shared_ptr<CallInvoker> jsInvoker);
+
+  std::optional<jsi::Object>
+  getViewTransitionInstance(jsi::Runtime &rt, const std::string &name, const std::string &pseudo);
+};
+
+} // namespace facebook::react

packages/react-native/ReactCommon/react/renderer/uimanager/UIManagerBinding.cpp

@@ -1147,43 +1147,6 @@ jsi::Value UIManagerBinding::get(
         });
   }
 
-  if (methodName == "unstable_getViewTransitionInstance") {
-    auto paramCount = 2;
-    return jsi::Function::createFromHostFunction(
-        runtime,
-        name,
-        paramCount,
-        [uiManager, methodName, paramCount](
-            jsi::Runtime& runtime,
-            const jsi::Value& /*thisValue*/,
-            const jsi::Value* arguments,
-            size_t count) -> jsi::Value {
-          validateArgumentCount(runtime, methodName, paramCount, count);
-
-          auto nameStr = arguments[0].asString(runtime).utf8(runtime);
-          auto pseudoStr = arguments[1].asString(runtime).utf8(runtime);
-
-          auto* viewTransitionDelegate = uiManager->getViewTransitionDelegate();
-          if (viewTransitionDelegate == nullptr) {
-            return jsi::Value::undefined();
-          }
-
-          auto instance = viewTransitionDelegate->getViewTransitionInstance(
-              nameStr, pseudoStr);
-          if (!instance) {
-            return jsi::Value::undefined();
-          }
-          auto result = jsi::Object(runtime);
-          result.setProperty(runtime, "x", instance->x);
-          result.setProperty(runtime, "y", instance->y);
-          result.setProperty(runtime, "width", instance->width);
-          result.setProperty(runtime, "height", instance->height);
-          result.setProperty(
-              runtime, "nativeTag", static_cast<double>(instance->nativeTag));
-          return result;
-        });
-  }
-
   return jsi::Value::undefined();
 }
 

packages/react-native/src/private/viewtransition/specs/NativeViewTransition.js

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import type {TurboModule} from '../../../../../Libraries/TurboModule/RCTExport';
+
+import * as TurboModuleRegistry from '../../../../../Libraries/TurboModule/TurboModuleRegistry';
+
+export interface Spec extends TurboModule {
+  +getViewTransitionInstance: (
+    name: string,
+    pseudo: string,
+  ) => ?{
+    x: number,
+    y: number,
+    width: number,
+    height: number,
+    nativeTag: number,
+  };
+}
+
+export default (TurboModuleRegistry.get<Spec>(
+  'NativeViewTransitionCxx',
+): ?Spec);