Expose methods of persistent yoga for Java

Summary: This diff extends the JNI version of yoga in order to allow Java instances of the YogaConfig class to receive a callback when a Yoga node is cloned.

Reviewed By: priteshrnandgaonkar

Differential Revision: D6918605

fbshipit-source-id: e424c78680c04e21154ebe21405671c4e90f6529

java/com/facebook/yoga/YogaConfig.java

@@ -23,6 +23,7 @@ public class YogaConfig {
 
   long mNativePointer;
   private YogaLogger mLogger;
+  private YogaNodeClonedFunction mNodeClonedFunction;
 
   private native long jni_YGConfigNew();
   public YogaConfig() {
@@ -80,4 +81,17 @@ public class YogaConfig {
   public YogaLogger getLogger() {
     return mLogger;
   }
+
+  private native void jni_YGConfigSetHasNodeClonedFunc(long nativePointer, boolean hasClonedFunc);
+
+  public void setOnNodeCloned(YogaNodeClonedFunction nodeClonedFunction) {
+    mNodeClonedFunction = nodeClonedFunction;
+    jni_YGConfigSetHasNodeClonedFunc(mNativePointer, nodeClonedFunction != null);
+  }
+
+  @DoNotStrip
+  public final void onNodeCloned(
+      YogaNode oldNode, YogaNode newNode, YogaNode parent, int childIndex) {
+    mNodeClonedFunction.onNodeCloned(oldNode, newNode, parent, childIndex);
+  }
 }

java/com/facebook/yoga/YogaNodeClonedFunction.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.yoga;
+
+import com.facebook.proguard.annotations.DoNotStrip;
+
+@DoNotStrip
+public interface YogaNodeClonedFunction {
+
+  @DoNotStrip
+  void onNodeCloned(YogaNode oldNode, YogaNode newNode, YogaNode parent, int childIndex);
+}