Add support for setChildren

Summary: This adds support for UIManager.setChildren on Android like D2757388 added for iOS.

Reviewed By: andreicoman11

Differential Revision: D3235369

fb-gh-sync-id: b538556ec4abdb606f9be26d1b74734046bca0cd
fbshipit-source-id: b538556ec4abdb606f9be26d1b74734046bca0cd

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

@@ -388,6 +388,51 @@ public class NativeViewHierarchyManager {
     }
   }
 
+  /**
+   * Simplified version of constructManageChildrenErrorMessage that only deals with adding children
+   * views
+   */
+  private static String constructSetChildrenErrorMessage(
+    ViewGroup viewToManage,
+    ViewGroupManager viewManager,
+    ReadableArray childrenTags) {
+    ViewAtIndex[] viewsToAdd = new ViewAtIndex[childrenTags.size()];
+    for (int i = 0; i < childrenTags.size(); i++) {
+      viewsToAdd[i] = new ViewAtIndex(childrenTags.getInt(i), i);
+    }
+    return constructManageChildrenErrorMessage(
+      viewToManage,
+      viewManager,
+      null,
+      viewsToAdd,
+      null
+    );
+  }
+
+  /**
+   * Simplified version of manageChildren that only deals with adding children views
+   */
+  public void setChildren(
+    int tag,
+    ReadableArray childrenTags) {
+    ViewGroup viewToManage = (ViewGroup) mTagsToViews.get(tag);
+    ViewGroupManager viewManager = (ViewGroupManager) resolveViewManager(tag);
+
+    for (int i = 0; i < childrenTags.size(); i++) {
+      View viewToAdd = mTagsToViews.get(childrenTags.getInt(i));
+      if (viewToAdd == null) {
+        throw new IllegalViewOperationException(
+          "Trying to add unknown view tag: "
+            + childrenTags.getInt(i) + "\n detail: " +
+            constructSetChildrenErrorMessage(
+              viewToManage,
+              viewManager,
+              childrenTags));
+      }
+      viewManager.addView(viewToManage, viewToAdd, i);
+    }
+  }
+
   /**
    * See {@link UIManagerModule#addMeasuredRootView}.
    *

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

@@ -14,6 +14,7 @@ import javax.annotation.Nullable;
 import android.util.SparseBooleanArray;
 
 import com.facebook.infer.annotation.Assertions;
+import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.bridge.ReadableMapKeySetIterator;
 
 /**
@@ -171,6 +172,27 @@ public class NativeViewHierarchyOptimizer {
     }
   }
 
+  /**
+   * Handles a setChildren call.  This is a simplification of handleManagerChildren that only adds
+   * children in index order of the childrenTags array
+   */
+  public void handleSetChildren(
+    ReactShadowNode nodeToManage,
+    ReadableArray childrenTags
+  ) {
+    if (!ENABLED) {
+      mUIViewOperationQueue.enqueueSetChildren(
+        nodeToManage.getReactTag(),
+        childrenTags);
+      return;
+    }
+
+    for (int i = 0; i < childrenTags.size(); i++) {
+      ReactShadowNode nodeToAdd = mShadowNodeRegistry.getNode(childrenTags.getInt(i));
+      addNodeToNode(nodeToManage, nodeToAdd, i);
+    }
+  }
+
   /**
    * Handles an updateLayout call. All updateLayout calls are collected and dispatched at the end
    * of a batch because updateLayout calls to layout-only nodes can necessitate multiple

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

@@ -323,6 +323,35 @@ public class UIImplementation {
     }
   }
 
+  /**
+   * An optimized version of manageChildren that is used for initial setting of child views.
+   * The children are assumed to be in index order
+   *
+   * @param viewTag tag of the parent
+   * @param childrenTags tags of the children
+   */
+  public void setChildren(
+    int viewTag,
+    ReadableArray childrenTags) {
+
+    ReactShadowNode cssNodeToManage = mShadowNodeRegistry.getNode(viewTag);
+
+    for (int i = 0; i < childrenTags.size(); i++) {
+      ReactShadowNode cssNodeToAdd = mShadowNodeRegistry.getNode(childrenTags.getInt(i));
+      if (cssNodeToAdd == null) {
+        throw new IllegalViewOperationException("Trying to add unknown view tag: "
+          + childrenTags.getInt(i));
+      }
+      cssNodeToManage.addChildAt(cssNodeToAdd, i);
+    }
+
+    if (!cssNodeToManage.isVirtual() && !cssNodeToManage.isVirtualAnchor()) {
+      mNativeViewHierarchyOptimizer.handleSetChildren(
+        cssNodeToManage,
+        childrenTags);
+    }
+  }
+
   /**
    * Replaces the View specified by oldTag with the View specified by newTag within oldTag's parent.
    */

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

@@ -231,6 +231,20 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
         removeFrom);
   }
 
+  /**
+   * Interface for fast tracking the initial adding of views.  Children view tags are assumed to be
+   * in order
+   *
+   * @param viewTag the view tag of the parent view
+   * @param childrenTags An array of tags to add to the parent in order
+   */
+  @ReactMethod
+  public void setChildren(
+    int viewTag,
+    ReadableArray childrenTags) {
+    mUIImplementation.setChildren(viewTag, childrenTags);
+  }
+
   /**
    * Replaces the View specified by oldTag with the View specified by newTag within oldTag's parent.
    * This resolves to a simple {@link #manageChildren} call, but React doesn't have enough info in

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

@@ -180,6 +180,25 @@ public class UIViewOperationQueue {
     }
   }
 
+  private final class SetChildrenOperation extends ViewOperation {
+
+    private final ReadableArray mChildrenTags;
+
+    public SetChildrenOperation(
+      int tag,
+      ReadableArray childrenTags) {
+      super(tag);
+      mChildrenTags = childrenTags;
+    }
+
+    @Override
+    public void execute() {
+      mNativeViewHierarchyManager.setChildren(
+        mTag,
+        mChildrenTags);
+    }
+  }
+
   private final class UpdateViewExtraData extends ViewOperation {
 
     private final Object mExtraData;
@@ -640,6 +659,13 @@ public class UIViewOperationQueue {
         new ManageChildrenOperation(reactTag, indicesToRemove, viewsToAdd, tagsToDelete));
   }
 
+  public void enqueueSetChildren(
+    int reactTag,
+    ReadableArray childrenTags) {
+    mOperations.add(
+      new SetChildrenOperation(reactTag, childrenTags));
+  }
+
   public void enqueueRegisterAnimation(Animation animation) {
     mOperations.add(new RegisterAnimationOperation(animation));
   }