convert ViewUtil to Kotlin (facebook#43799)

Summary:
Pull Request resolved: facebook#43799

convert Java to Kotlin: `/react/uimanager/common/ViewUtil.java`

Changelog:
[Internal] internal

Differential Revision: D55651762

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -5372,12 +5372,11 @@ public abstract interface annotation class com/facebook/react/uimanager/common/U
 	public static final field FABRIC I
 }
 
-public class com/facebook/react/uimanager/common/ViewUtil {
+public final class com/facebook/react/uimanager/common/ViewUtil {
 	public static final field NO_SURFACE_ID I
-	public fun <init> ()V
-	public static fun getUIManagerType (I)I
-	public static fun getUIManagerType (II)I
-	public static fun isRootTag (I)Z
+	public static final fun getUIManagerType (I)I
+	public static final fun getUIManagerType (II)I
+	public static final fun isRootTag (I)Z
 }
 
 public abstract interface class com/facebook/react/uimanager/debug/NotThreadSafeViewHierarchyUpdateDebugListener {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/common/ViewUtil.kt

@@ -0,0 +1,65 @@
+/*
+ * 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:JvmName("ViewUtil")
+
+package com.facebook.react.uimanager.common
+
+import com.facebook.react.uimanager.common.UIManagerType.DEFAULT
+import com.facebook.react.uimanager.common.UIManagerType.FABRIC
+
+public const val NO_SURFACE_ID: Int = -1
+
+/**
+ * Counter for uniquely identifying views. - % 2 === 0 means it is a Fabric tag. See
+ * https://github.com/facebook/react/pull/12587
+ *
+ * @param viewTag [int] tag of the view this is event is dispatched to
+ */
+@UIManagerType
+public fun getUIManagerType(viewTag: Int): Int {
+  return if (viewTag % 2 == 0) {
+    FABRIC
+  } else {
+    DEFAULT
+  }
+}
+
+/**
+ * Version of getUIManagerType that uses both surfaceId and viewTag heuristics
+ *
+ * @param viewTag {@link int} tag of the view this is event is dispatched to
+ * @param surfaceId {@link int} ID of the corresponding surface
+ */
+@UIManagerType
+public fun getUIManagerType(viewTag: Int, surfaceId: Int): Int {
+  // We have a contract that Fabric events *always* have a SurfaceId passed in, and non-Fabric
+  // events NEVER have a SurfaceId passed in (the default/placeholder of -1 is passed in instead).
+  //
+  // Why does this matter?
+  // Events can be sent to Views that are part of the View hierarchy *but not directly managed
+  // by React Native*. For example, embedded custom hierarchies, Litho hierarchies, etc.
+  // In those cases it's important to know that the Event should be sent to the Fabric or
+  // non-Fabric UIManager, and we cannot use the ViewTag for inference since it's not controlled
+  // by RN and is essentially a random number.
+  // At some point it would be great to pass the SurfaceContext here instead.
+  @UIManagerType val uiManagerType: Int = if (surfaceId == -1) DEFAULT else FABRIC
+  if (uiManagerType == DEFAULT && !isRootTag(viewTag)) {
+    // TODO (T123064648): Some events for Fabric still didn't have the surfaceId set, so if it's
+    // not a React RootView, double check if the tag belongs to Fabric.
+    if (viewTag % 2 == 0) {
+      return FABRIC
+    }
+  }
+  return uiManagerType
+}
+
+/**
+ * @param viewTag [int] react tag
+ * @return if the react tag received by parameter is a RootTag or not.
+ */
+public fun isRootTag(viewTag: Int): Boolean = viewTag % 10 == 1