Convert InteropEvent and InteropEventEmitter to Kotlin (facebook#42358)

Summary:
Pull Request resolved: facebook#42358

Just converting those two classes to Kotlin as I was going over them.

Changelog:
[Internal] [Changed] - Convert InteropEvent and InteropEventEmitter to Kotlin

Reviewed By: javache

Differential Revision: D52869490

fbshipit-source-id: 2d585dd3d21dc89c5e55de645e9519d36f67b849

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/interop/InteropEvent.kt

@@ -0,0 +1,27 @@
+/*
+ * 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.internal.interop
+
+import com.facebook.react.bridge.WritableMap
+import com.facebook.react.uimanager.events.Event
+
+/**
+ * An [Event] class used by the [InteropEventEmitter]. This class is just holding the event name and
+ * the data which is received by the `receiveEvent` method and will be passed over the the
+ * [com.facebook.react.uimanager.events.EventDispatcher]
+ */
+class InteropEvent(
+    @get:JvmName("eventName") val eventName: String,
+    @get:JvmName("eventData") val eventData: WritableMap?,
+    surfaceId: Int,
+    viewTag: Int
+) : Event<InteropEvent>(surfaceId, viewTag) {
+  override fun getEventName(): String = eventName
+
+  override fun getEventData(): WritableMap? = eventData
+}

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/interop/InteropEventEmitter.kt

@@ -0,0 +1,55 @@
+/*
+ * 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.
+ */
+
+@file:Suppress("DEPRECATION") // We want to use RCTEventEmitter for interop purposes
+
+package com.facebook.react.internal.interop
+
+import com.facebook.react.bridge.ReactContext
+import com.facebook.react.bridge.WritableArray
+import com.facebook.react.bridge.WritableMap
+import com.facebook.react.common.annotations.VisibleForTesting
+import com.facebook.react.uimanager.UIManagerHelper
+import com.facebook.react.uimanager.events.EventDispatcher
+import com.facebook.react.uimanager.events.RCTEventEmitter
+
+/**
+ * A reimplementation of [RCTEventEmitter] which is using a [EventDispatcher] under the hood.
+ *
+ * On Fabric, you're supposed to use [EventDispatcher] to dispatch events. However, we provide an
+ * interop layer for non-Fabric migrated components.
+ *
+ * This instance will be returned if the user is invoking `context.getJsModule(RCTEventEmitter) and
+ * is providing support for the `receiveEvent` method, so that non-Fabric ViewManagers can continue
+ * to deliver events also when Fabric is turned on.
+ */
+class InteropEventEmitter(private val reactContext: ReactContext) : RCTEventEmitter {
+  private var eventDispatcherOverride: EventDispatcher? = null
+
+  @Deprecated("Deprecated in Java")
+  override fun receiveEvent(targetReactTag: Int, eventName: String, eventData: WritableMap?) {
+    val dispatcher: EventDispatcher? =
+        eventDispatcherOverride
+            ?: UIManagerHelper.getEventDispatcherForReactTag(reactContext, targetReactTag)
+    val surfaceId = UIManagerHelper.getSurfaceId(reactContext)
+    dispatcher?.dispatchEvent(InteropEvent(eventName, eventData, surfaceId, targetReactTag))
+  }
+
+  override fun receiveTouches(
+      eventName: String,
+      touches: WritableArray,
+      changedIndices: WritableArray
+  ) {
+    throw UnsupportedOperationException(
+        "EventEmitter#receiveTouches is not supported by the Fabric Interop Layer")
+  }
+
+  @VisibleForTesting
+  fun overrideEventDispatcher(eventDispatcherOverride: EventDispatcher?) {
+    this.eventDispatcherOverride = eventDispatcherOverride
+  }
+}

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/internal/interop/InteropEventEmitterTest.kt

@@ -5,8 +5,11 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+@file:Suppress("DEPRECATION") // We want to use RCTEventEmitter for interop purposes
+
 package com.facebook.react.internal.interop
 
+import com.facebook.react.bridge.JavaOnlyArray
 import com.facebook.react.bridge.JavaOnlyMap
 import com.facebook.react.bridge.ReactApplicationContext
 import com.facebook.react.bridge.ReactContext
@@ -50,15 +53,15 @@ class InteropEventEmitterTest {
 
     eventEmitter.receiveEvent(42, "onTest", eventData)
 
-    val event = eventDispatcher.getRecordedDispatchedEvents().get(0) as InteropEvent
-    val dispatchedEventData = event.getEventData()
+    val event = eventDispatcher.getRecordedDispatchedEvents()[0] as InteropEvent
+    val dispatchedEventData = event.eventData
     assertNotNull(dispatchedEventData)
     assertEquals("indigo", dispatchedEventData!!.getString("color"))
   }
 
   @Test(expected = java.lang.UnsupportedOperationException::class)
   fun receiveTouches_isNotSupported() {
     val eventEmitter = InteropEventEmitter(reactContext)
-    eventEmitter.receiveTouches("a touch", null, null)
+    eventEmitter.receiveTouches("a touch", JavaOnlyArray.of(), JavaOnlyArray.of())
   }
 }