Support View Manager Commands

Summary: Supporting View Manager Commands on the new UIManager in Fabric. This is needed for things like scrollTo on ScrollView.

Reviewed By: JoshuaGross

Differential Revision: D16175575

fbshipit-source-id: a74effdf7e47b56a150a4e3fb6c4d787659e0250

ReactAndroid/src/main/java/com/facebook/react/fabric/jni/Binding.cpp

@@ -248,6 +248,11 @@ inline local_ref<ReadableMap::javaobject> castReadableMap(
   return make_local(reinterpret_cast<ReadableMap::javaobject>(nativeMap.get()));
 }
 
+inline local_ref<ReadableArray::javaobject> castReadableArray(
+  local_ref<ReadableNativeArray::javaobject> nativeArray) {
+  return make_local(reinterpret_cast<ReadableArray::javaobject>(nativeArray.get()));
+}
+
 // TODO: this method will be removed when binding for components are code-gen
 local_ref<JString> getPlatformComponentName(const ShadowView &shadowView) {
   local_ref<JString> componentName;
@@ -672,6 +677,31 @@ void Binding::schedulerDidRequestPreliminaryViewAllocation(
       isLayoutableShadowNode);
 }
 
+void Binding::schedulerDidDispatchCommand(
+  const ShadowView &shadowView,
+  std::string const &commandName,
+  folly::dynamic const args) {
+
+  jni::global_ref<jobject> localJavaUIManager = getJavaUIManager();
+  if (!localJavaUIManager) {
+    LOG(ERROR) << "Binding::schedulerDidDispatchCommand: JavaUIManager disappeared";
+    return;
+  }
+
+  static auto dispatchCommand =
+    jni::findClassStatic(UIManagerJavaDescriptor)
+      ->getMethod<void(
+        jint, jstring, ReadableArray::javaobject)>(
+        "dispatchCommand");
+
+  local_ref<JString> command = make_jstring(commandName);
+
+  local_ref<ReadableArray::javaobject> argsArray = castReadableArray(
+    ReadableNativeArray::newObjectCxxArgs(args));
+
+  dispatchCommand(localJavaUIManager, shadowView.tag, command.get(), argsArray.get());
+}
+
 void Binding::registerNatives() {
   registerHybrid(
       {makeNativeMethod("initHybrid", Binding::initHybrid),

ReactAndroid/src/main/java/com/facebook/react/fabric/jni/Binding.h

@@ -82,6 +82,11 @@ class Binding : public jni::HybridClass<Binding>, public SchedulerDelegate {
       const SurfaceId surfaceId,
       const ShadowView &shadowView);
 
+  void schedulerDidDispatchCommand(
+    const ShadowView &shadowView,
+    std::string const &commandName,
+    folly::dynamic const args);
+
   void setPixelDensity(float pointScaleFactor);
 
   void uninstallFabricUIManager();