Fix appendChild

Reviewed By: mdvacca

Differential Revision: D7128443

fbshipit-source-id: 4eedea4df2b636eb9589cbe5e84c5c6a8aa33539

ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManagerModule.java

@@ -22,6 +22,7 @@
 import com.facebook.react.uimanager.ReactStylesDiffMap;
 import com.facebook.react.uimanager.ThemedReactContext;
 import com.facebook.react.uimanager.UIViewOperationQueue;
+import com.facebook.react.uimanager.ViewAtIndex;
 import com.facebook.react.uimanager.ViewManager;
 import com.facebook.react.uimanager.ViewManagerRegistry;
 import com.facebook.react.uimanager.common.MeasureSpecProvider;
@@ -179,8 +180,16 @@ private void assertReactShadowNodeCopy(ReactShadowNode source, ReactShadowNode t
   @Nullable
   public void appendChild(ReactShadowNode parent, ReactShadowNode child) {
     try {
-      parent.addChildAt(child, parent.getChildCount());
-      addChild(parent.getReactTag(), child.getReactTag());
+      int childIndex = parent.getChildCount();
+      parent.addChildAt(child, childIndex);
+      ViewAtIndex[] viewsToAdd =
+        new ViewAtIndex[]{new ViewAtIndex(child.getReactTag(), childIndex)};
+      mUIViewOperationQueue.enqueueManageChildren(
+        parent.getReactTag(),
+        null,
+        viewsToAdd,
+        null
+      );
     } catch (Exception e) {
       handleException(parent.getThemedContext(), e);
     }
@@ -209,8 +218,7 @@ public void completeRoot(int rootTag, List<ReactShadowNode> childList) {
         "Root view with tag " + rootTag + " must be added before completeRoot is called");
       for (int i = 0; i < childList.size(); i++) {
         ReactShadowNode child = childList.get(i);
-        rootNode.addChildAt(child, i);
-        addChild(rootTag, child.getReactTag());
+        appendChild(rootNode, child);
       }
 
       calculateRootLayout(rootNode);
@@ -222,15 +230,6 @@ public void completeRoot(int rootTag, List<ReactShadowNode> childList) {
     }
   }
 
-  private void addChild(int parent, int child) {
-    JavaOnlyArray childrenTags = new JavaOnlyArray();
-    childrenTags.pushInt(child);
-    mUIViewOperationQueue.enqueueSetChildren(
-      parent,
-      childrenTags
-    );
-  }
-
   private void calculateRootLayout(ReactShadowNode cssRoot) {
     cssRoot.calculateLayout();
   }

ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewAtIndex.java

@@ -13,7 +13,7 @@
  * Data structure that couples view tag to it's index in parent view. Used for managing children
  * operation.
  */
-/* package */ class ViewAtIndex {
+public class ViewAtIndex {
   public static Comparator<ViewAtIndex> COMPARATOR = new Comparator<ViewAtIndex>() {
     @Override
     public int compare(ViewAtIndex lhs, ViewAtIndex rhs) {