Update the New App template to reduce the amount of C++ code in user space

ReactAndroid/Android-prebuilt.mk

@@ -175,6 +175,14 @@ LOCAL_EXPORT_C_INCLUDES := \
   $(REACT_COMMON_DIR)/react/renderer/componentregistry
 include $(PREBUILT_SHARED_LIBRARY)
 
+# react_newarchdefaults
+include $(CLEAR_VARS)
+LOCAL_MODULE := react_newarchdefaults
+LOCAL_SRC_FILES := $(REACT_NDK_EXPORT_DIR)/$(TARGET_ARCH_ABI)/libreact_newarchdefaults.so
+LOCAL_EXPORT_C_INCLUDES := \
+  $(REACT_ANDROID_SRC_DIR)/jni/react/newarchdefaults
+include $(PREBUILT_SHARED_LIBRARY)
+
 # jsi
 include $(CLEAR_VARS)
 LOCAL_MODULE := jsi

ReactAndroid/build.gradle

@@ -298,6 +298,7 @@ android {
                     "jsijniprofiler",
                     "reactnativeblob",
                     "reactperfloggerjni",
+                    "react_newarchdefaults",
                     "turbomodulejsijni",
                     "fabricjni"
             }

ReactAndroid/cmake-utils/Android-prebuilt.cmake

@@ -203,6 +203,14 @@ set_target_properties(react_render_componentregistry
         ${REACT_NDK_EXPORT_DIR}/${ANDROID_ABI}/libreact_render_componentregistry.so)
 target_include_directories(react_render_componentregistry INTERFACE ${REACT_COMMON_DIR}/react/renderer/componentregistry)
 
+## react_newarchdefaults
+add_library(react_newarchdefaults SHARED IMPORTED GLOBAL)
+set_target_properties(react_newarchdefaults
+        PROPERTIES
+        IMPORTED_LOCATION
+        ${REACT_NDK_EXPORT_DIR}/${ANDROID_ABI}/libreact_newarchdefaults.so)
+target_include_directories(react_newarchdefaults INTERFACE ${REACT_ANDROID_SRC_DIR}/jni/react/newarchdefaults)
+
 ## jsi
 add_library(jsi SHARED IMPORTED GLOBAL)
 set_target_properties(jsi

ReactAndroid/cmake-utils/ReactNative-application.cmake

@@ -40,6 +40,7 @@ target_link_libraries(${CMAKE_PROJECT_NAME}
         react_codegen_rncore
         react_debug
         react_nativemodule_core
+        react_newarchdefaults
         react_render_componentregistry
         react_render_core
         react_render_debug

ReactAndroid/src/main/java/com/facebook/react/defaults/DefaultComponentsRegistry.kt

@@ -15,9 +15,8 @@ import com.facebook.react.fabric.ComponentFactory
  * A utility class that provides users a ComponentRegistry they can customize with a C++
  * implementation of its native methods.
  *
- * Please note that you need to provide a native implementation for the method initHybrid for this
- * class, making sure the Java Descriptor is:
- * Lcom/facebook/react/defaults/DefaultComponentsRegistry;
+ * This class works together with the [DefaultNativeEntryPoint] and it's C++ implementation is
+ * hosted inside the React Native framwork
  */
 @DoNotStrip
 class DefaultComponentsRegistry

ReactAndroid/src/main/java/com/facebook/react/defaults/DefaultNativeEntryPoint.kt

@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.defaults
+
+import com.facebook.jni.HybridData
+import com.facebook.proguard.annotations.DoNotStrip
+import com.facebook.soloader.SoLoader
+
+/**
+ * A utility class that serves as an entry point for users to register all the custom Fabric
+ * Components and Turbo Native Modules.
+ *
+ * This class needs to be invoked as `DefaultNativeEntryPoint.load("...")` by passing the name of
+ * the dynamic library to load.
+ *
+ * This class works together with the [DefaultNativeEntryPoint] and it's C++ implementation is
+ * hosted inside the React Native framework
+ */
+@DoNotStrip
+class DefaultNativeEntryPoint @DoNotStrip private constructor() {
+
+  @DoNotStrip private val hybridData: HybridData = initHybrid()
+
+  @DoNotStrip private external fun initHybrid(): HybridData
+
+  companion object {
+    @JvmStatic
+    fun load(dynamicLibraryName: String) {
+      SoLoader.loadLibrary("react_newarchdefaults")
+      SoLoader.loadLibrary(dynamicLibraryName)
+      DefaultNativeEntryPoint()
+    }
+  }
+}

ReactAndroid/src/main/java/com/facebook/react/defaults/DefaultTurboModuleManagerDelegate.kt

@@ -17,9 +17,8 @@ import com.facebook.react.bridge.ReactApplicationContext
  * A utility class that allows you to simplify the setup of a
  * [ReactPackageTurboModuleManagerDelegate] for new apps in Open Source.
  *
- * Please note that you need to provide a native implementation for the method initHybrid for this
- * class, making sure the Java Descriptor is:
- * Lcom/facebook/react/defaults/DefaultTurboModuleManagerDelegate;
+ * This class works together with the [DefaultNativeEntryPoint] and it's C++ implementation is
+ * hosted inside the React Native framwork
  */
 class DefaultTurboModuleManagerDelegate
 private constructor(context: ReactApplicationContext, packages: List<ReactPackage>) :

ReactAndroid/src/main/jni/CMakeLists.txt

@@ -101,6 +101,7 @@ add_react_android_subdir(src/main/jni/react/uimanager)
 add_react_android_subdir(src/main/jni/react/mapbuffer)
 add_react_android_subdir(src/main/jni/react/reactnativeblob)
 add_react_android_subdir(src/main/jni/react/fabric)
+add_react_android_subdir(src/main/jni/react/newarchdefaults)
 add_react_android_subdir(src/main/jni/react/hermes/reactexecutor)
 add_react_android_subdir(src/main/jni/react/hermes/instrumentation/)
 

ReactAndroid/src/main/jni/react/newarchdefaults/CMakeLists.txt

@@ -0,0 +1,22 @@
+# 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.
+
+cmake_minimum_required(VERSION 3.13)
+set(CMAKE_VERBOSE_MAKEFILE on)
+
+add_compile_options(-fexceptions -frtti -std=c++17 -Wall -DLOG_TAG=\"ReactNative\")
+
+file(GLOB react_newarchdefaults_SRC CONFIGURE_DEPENDS *.cpp)
+
+add_library(react_newarchdefaults SHARED ${react_newarchdefaults_SRC})
+
+target_include_directories(react_newarchdefaults PUBLIC .)
+
+target_link_libraries(react_newarchdefaults
+        fbjni
+        fabricjni
+        react_nativemodule_core
+        react_codegen_rncore
+        jsi)

packages/rn-tester/android/app/src/main/jni/RNTesterComponentsRegistry.cpp → ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.cpp

@@ -5,33 +5,34 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "RNTesterComponentsRegistry.h"
+#include "DefaultComponentsRegistry.h"
 
 #include <CoreComponentsRegistry.h>
 #include <fbjni/fbjni.h>
 #include <react/renderer/componentregistry/ComponentDescriptorProviderRegistry.h>
-#include <react/renderer/components/AppSpecs/ComponentDescriptors.h>
 #include <react/renderer/components/rncore/ComponentDescriptors.h>
 
 namespace facebook {
 namespace react {
 
-RNTesterComponentsRegistry::RNTesterComponentsRegistry(
-    ComponentFactory *delegate)
+std::function<void(std::shared_ptr<ComponentDescriptorProviderRegistry const>)>
+    DefaultComponentsRegistry::registerComponentDescriptorsFromEntryPoint{};
+
+DefaultComponentsRegistry::DefaultComponentsRegistry(ComponentFactory *delegate)
     : delegate_(delegate) {}
 
 std::shared_ptr<ComponentDescriptorProviderRegistry const>
-RNTesterComponentsRegistry::sharedProviderRegistry() {
+DefaultComponentsRegistry::sharedProviderRegistry() {
   auto providerRegistry = CoreComponentsRegistry::sharedProviderRegistry();
 
-  providerRegistry->add(concreteComponentDescriptorProvider<
-                        RNTMyNativeViewComponentDescriptor>());
+  (DefaultComponentsRegistry::registerComponentDescriptorsFromEntryPoint)(
+      providerRegistry);
 
   return providerRegistry;
 }
 
-jni::local_ref<RNTesterComponentsRegistry::jhybriddata>
-RNTesterComponentsRegistry::initHybrid(
+jni::local_ref<DefaultComponentsRegistry::jhybriddata>
+DefaultComponentsRegistry::initHybrid(
     jni::alias_ref<jclass>,
     ComponentFactory *delegate) {
   auto instance = makeCxxInstance(delegate);
@@ -40,7 +41,7 @@ RNTesterComponentsRegistry::initHybrid(
       [](EventDispatcher::Weak const &eventDispatcher,
          ContextContainer::Shared const &contextContainer)
       -> ComponentDescriptorRegistry::Shared {
-    auto registry = RNTesterComponentsRegistry::sharedProviderRegistry()
+    auto registry = DefaultComponentsRegistry::sharedProviderRegistry()
                         ->createComponentDescriptorRegistry(
                             {eventDispatcher, contextContainer});
 
@@ -59,9 +60,9 @@ RNTesterComponentsRegistry::initHybrid(
   return instance;
 }
 
-void RNTesterComponentsRegistry::registerNatives() {
+void DefaultComponentsRegistry::registerNatives() {
   registerHybrid({
-      makeNativeMethod("initHybrid", RNTesterComponentsRegistry::initHybrid),
+      makeNativeMethod("initHybrid", DefaultComponentsRegistry::initHybrid),
   });
 }
 

packages/rn-tester/android/app/src/main/jni/RNTesterComponentsRegistry.h → ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.h

@@ -11,19 +11,24 @@
 #include <fbjni/fbjni.h>
 #include <react/renderer/componentregistry/ComponentDescriptorProviderRegistry.h>
 #include <react/renderer/componentregistry/ComponentDescriptorRegistry.h>
+#include <react/renderer/core/ConcreteComponentDescriptor.h>
 
 namespace facebook {
 namespace react {
 
-class RNTesterComponentsRegistry
-    : public facebook::jni::HybridClass<RNTesterComponentsRegistry> {
+class DefaultComponentsRegistry
+    : public facebook::jni::HybridClass<DefaultComponentsRegistry> {
  public:
   constexpr static auto kJavaDescriptor =
       "Lcom/facebook/react/defaults/DefaultComponentsRegistry;";
 
   static void registerNatives();
 
-  RNTesterComponentsRegistry(ComponentFactory *delegate);
+  static std::function<void(
+      std::shared_ptr<ComponentDescriptorProviderRegistry const>)>
+      registerComponentDescriptorsFromEntryPoint;
+
+  DefaultComponentsRegistry(ComponentFactory *delegate);
 
  private:
   friend HybridBase;

ReactAndroid/src/main/jni/react/newarchdefaults/DefaultTurboModuleManagerDelegate.cpp

@@ -0,0 +1,51 @@
+/*
+ * 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 "DefaultTurboModuleManagerDelegate.h"
+
+#include <rncore.h>
+
+namespace facebook {
+namespace react {
+
+std::function<std::shared_ptr<TurboModule>(
+    const std::string &,
+    const JavaTurboModule::InitParams &)>
+    DefaultTurboModuleManagerDelegate::moduleProvidersFromEntryPoint { nullptr };
+
+jni::local_ref<DefaultTurboModuleManagerDelegate::jhybriddata>
+DefaultTurboModuleManagerDelegate::initHybrid(jni::alias_ref<jhybridobject>) {
+  return makeCxxInstance();
+}
+
+void DefaultTurboModuleManagerDelegate::registerNatives() {
+  registerHybrid({
+      makeNativeMethod(
+          "initHybrid", DefaultTurboModuleManagerDelegate::initHybrid),
+  });
+}
+
+std::shared_ptr<TurboModule> DefaultTurboModuleManagerDelegate::getTurboModule(
+    const std::string &name,
+    const std::shared_ptr<CallInvoker> &jsInvoker) {
+  // Not implemented yet: provide pure-C++ NativeModules here.
+  return nullptr;
+}
+
+std::shared_ptr<TurboModule> DefaultTurboModuleManagerDelegate::getTurboModule(
+    const std::string &name,
+    const JavaTurboModule::InitParams &params) {
+  auto resolvedModule = (DefaultTurboModuleManagerDelegate::
+                             moduleProvidersFromEntryPoint)(name, params);
+  if (resolvedModule != nullptr) {
+    return resolvedModule;
+  }
+  return rncore_ModuleProvider(name, params);
+}
+
+} // namespace react
+} // namespace facebook

packages/rn-tester/android/app/src/main/jni/RNTesterTurboModuleManagerDelegate.h → ReactAndroid/src/main/jni/react/newarchdefaults/DefaultTurboModuleManagerDelegate.h

@@ -8,16 +8,17 @@
 #include <memory>
 #include <string>
 
+#include <ReactCommon/JavaTurboModule.h>
+#include <ReactCommon/TurboModule.h>
 #include <ReactCommon/TurboModuleManagerDelegate.h>
 #include <fbjni/fbjni.h>
 
 namespace facebook {
 namespace react {
 
-class RNTesterTurboModuleManagerDelegate
-    : public jni::HybridClass<
-          RNTesterTurboModuleManagerDelegate,
-          TurboModuleManagerDelegate> {
+class DefaultTurboModuleManagerDelegate : public jni::HybridClass<
+                                              DefaultTurboModuleManagerDelegate,
+                                              TurboModuleManagerDelegate> {
  public:
   static constexpr auto kJavaDescriptor =
       "Lcom/facebook/react/defaults/DefaultTurboModuleManagerDelegate;";
@@ -26,6 +27,11 @@ class RNTesterTurboModuleManagerDelegate
 
   static void registerNatives();
 
+  static std::function<std::shared_ptr<TurboModule>(
+      const std::string &,
+      const JavaTurboModule::InitParams &)>
+      moduleProvidersFromEntryPoint;
+
   std::shared_ptr<TurboModule> getTurboModule(
       const std::string &name,
       const std::shared_ptr<CallInvoker> &jsInvoker) override;

ReactAndroid/src/main/jni/react/newarchdefaults/OnLoad.cpp

@@ -0,0 +1,18 @@
+/*
+ * 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 <fbjni/fbjni.h>
+
+#include "DefaultComponentsRegistry.h"
+#include "DefaultTurboModuleManagerDelegate.h"
+
+JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *) {
+  return facebook::jni::initialize(vm, [] {
+    facebook::react::DefaultTurboModuleManagerDelegate::registerNatives();
+    facebook::react::DefaultComponentsRegistry::registerNatives();
+  });
+}

packages/rn-tester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterApplication.java

@@ -17,6 +17,7 @@
 import com.facebook.react.bridge.NativeModule;
 import com.facebook.react.bridge.ReactApplicationContext;
 import com.facebook.react.config.ReactFeatureFlags;
+import com.facebook.react.defaults.DefaultNativeEntryPoint;
 import com.facebook.react.defaults.DefaultReactNativeHost;
 import com.facebook.react.module.model.ReactModuleInfo;
 import com.facebook.react.module.model.ReactModuleInfoProvider;
@@ -122,7 +123,7 @@ public void onCreate() {
     ReactFontManager.getInstance().addCustomFont(this, "Rubik", R.font.rubik);
     super.onCreate();
     SoLoader.init(this, /* native exopackage */ false);
-    SoLoader.loadLibrary(BuildConfig.DYNAMIC_LIBRARY_NAME);
+    DefaultNativeEntryPoint.load(BuildConfig.DYNAMIC_LIBRARY_NAME);
     ReactNativeFlipper.initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
   }