Support to enable/disable Fabric in ReactFragment (#36263)

Summary:
New Architecture Support missing in React Native Fragment, added same.

Changelog:
[Android] [Added] - Support to enable/disable Fabric in ReactFragment

Pull Request resolved: #36263

Test Plan:
<details>
  <summary>Kotlin Code Snippet to test:</summary>
  <p>

```kotlin
supportFragmentManager
  .beginTransaction()
  .add(android.R.id.content,
     ReactFragment.Builder()
       .setComponentName("componentName")
       .setFabricEnabled(true)
       .build())
  .commit()
```

  </p>
</details>

Reviewed By: mdvacca

Differential Revision: D43701078

Pulled By: cortinico

fbshipit-source-id: 659ed2b4cf6619c6d64b803a198a93ff84b574fe

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactDelegate.java

@@ -11,6 +11,7 @@
 import android.content.Intent;
 import android.os.Bundle;
 import android.view.KeyEvent;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.facebook.infer.annotation.Assertions;
 import com.facebook.react.devsupport.DoubleTapReloadRecognizer;
@@ -33,6 +34,8 @@ public class ReactDelegate {
 
   private ReactNativeHost mReactNativeHost;
 
+  private boolean mFabricEnabled = false;
+
   public ReactDelegate(
       Activity activity,
       ReactNativeHost reactNativeHost,
@@ -45,6 +48,20 @@ public ReactDelegate(
     mReactNativeHost = reactNativeHost;
   }
 
+  public ReactDelegate(
+      Activity activity,
+      ReactNativeHost reactNativeHost,
+      @Nullable String appKey,
+      @Nullable Bundle launchOptions,
+      boolean fabricEnabled) {
+    mActivity = activity;
+    mMainComponentName = appKey;
+    mLaunchOptions = composeLaunchOptions(launchOptions);
+    mDoubleTapReloadRecognizer = new DoubleTapReloadRecognizer();
+    mReactNativeHost = reactNativeHost;
+    mFabricEnabled = fabricEnabled;
+  }
+
   public void onHostResume() {
     if (getReactNativeHost().hasInstance()) {
       if (mActivity instanceof DefaultHardwareBackBtnHandler) {
@@ -109,7 +126,9 @@ public ReactRootView getReactRootView() {
   }
 
   protected ReactRootView createRootView() {
-    return new ReactRootView(mActivity);
+    ReactRootView reactRootView = new ReactRootView(mActivity);
+    reactRootView.setIsFabric(isFabricEnabled());
+    return reactRootView;
   }
 
   /**
@@ -144,4 +163,24 @@ private ReactNativeHost getReactNativeHost() {
   public ReactInstanceManager getReactInstanceManager() {
     return getReactNativeHost().getReactInstanceManager();
   }
+
+  /**
+   * Override this method if you wish to selectively toggle Fabric for a specific surface. This will
+   * also control if Concurrent Root (React 18) should be enabled or not.
+   *
+   * @return true if Fabric is enabled for this Activity, false otherwise.
+   */
+  protected boolean isFabricEnabled() {
+    return mFabricEnabled;
+  }
+
+  private @NonNull Bundle composeLaunchOptions(Bundle composedLaunchOptions) {
+    if (isFabricEnabled()) {
+      if (composedLaunchOptions == null) {
+        composedLaunchOptions = new Bundle();
+      }
+      composedLaunchOptions.putBoolean("concurrentRoot", true);
+    }
+    return composedLaunchOptions;
+  }
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactFragment.java

@@ -16,6 +16,7 @@
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 import com.facebook.react.modules.core.PermissionAwareActivity;
@@ -29,6 +30,7 @@ public class ReactFragment extends Fragment implements PermissionAwareActivity {
 
   protected static final String ARG_COMPONENT_NAME = "arg_component_name";
   protected static final String ARG_LAUNCH_OPTIONS = "arg_launch_options";
+  protected static final String ARG_FABRIC_ENABLED = "arg_fabric_enabled";
 
   private ReactDelegate mReactDelegate;
 
@@ -40,13 +42,16 @@ public ReactFragment() {
 
   /**
    * @param componentName The name of the react native component
+   * @param fabricEnabled Flag to enable Fabric for ReactFragment
    * @return A new instance of fragment ReactFragment.
    */
-  private static ReactFragment newInstance(String componentName, Bundle launchOptions) {
+  private static ReactFragment newInstance(
+      String componentName, Bundle launchOptions, Boolean fabricEnabled) {
     ReactFragment fragment = new ReactFragment();
     Bundle args = new Bundle();
     args.putString(ARG_COMPONENT_NAME, componentName);
     args.putBundle(ARG_LAUNCH_OPTIONS, launchOptions);
+    args.putBoolean(ARG_FABRIC_ENABLED, fabricEnabled);
     fragment.setArguments(args);
     return fragment;
   }
@@ -57,15 +62,18 @@ public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     String mainComponentName = null;
     Bundle launchOptions = null;
+    Boolean fabricEnabled = null;
     if (getArguments() != null) {
       mainComponentName = getArguments().getString(ARG_COMPONENT_NAME);
       launchOptions = getArguments().getBundle(ARG_LAUNCH_OPTIONS);
+      fabricEnabled = getArguments().getBoolean(ARG_FABRIC_ENABLED);
     }
     if (mainComponentName == null) {
       throw new IllegalStateException("Cannot loadApp if component name is null");
     }
     mReactDelegate =
-        new ReactDelegate(getActivity(), getReactNativeHost(), mainComponentName, launchOptions);
+        new ReactDelegate(
+            getActivity(), getReactNativeHost(), mainComponentName, launchOptions, fabricEnabled);
   }
 
   /**
@@ -85,7 +93,7 @@ protected ReactDelegate getReactDelegate() {
 
   @Override
   public View onCreateView(
-      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+      @NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
     mReactDelegate.loadApp();
     return mReactDelegate.getReactRootView();
   }
@@ -140,7 +148,7 @@ public boolean onKeyUp(int keyCode, KeyEvent event) {
 
   @Override
   public void onRequestPermissionsResult(
-      int requestCode, String[] permissions, int[] grantResults) {
+      int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
     super.onRequestPermissionsResult(requestCode, permissions, grantResults);
     if (mPermissionListener != null
         && mPermissionListener.onRequestPermissionsResult(requestCode, permissions, grantResults)) {
@@ -170,12 +178,14 @@ public void requestPermissions(
   /** Builder class to help instantiate a ReactFragment */
   public static class Builder {
 
-    String mComponentName;
-    Bundle mLaunchOptions;
+    @Nullable String mComponentName;
+    @Nullable Bundle mLaunchOptions;
+    @Nullable Boolean mFabricEnabled;
 
     public Builder() {
       mComponentName = null;
       mLaunchOptions = null;
+      mFabricEnabled = null;
     }
 
     /**
@@ -201,7 +211,12 @@ public Builder setLaunchOptions(Bundle launchOptions) {
     }
 
     public ReactFragment build() {
-      return ReactFragment.newInstance(mComponentName, mLaunchOptions);
+      return ReactFragment.newInstance(mComponentName, mLaunchOptions, mFabricEnabled);
+    }
+
+    public Builder setFabricEnabled(boolean fabricEnabled) {
+      mFabricEnabled = fabricEnabled;
+      return this;
     }
   }
 }