react-native/ReactAndroid/src/main/java/com/facebook/react/animated/AnimatedAddition.java

package com.facebook.react.animated;

import com.facebook.react.bridge.JSApplicationCausedNativeException;
import com.facebook.react.bridge.ReadableArray;
import com.facebook.react.bridge.ReadableMap;

/**
 * Animated node that plays a role of value aggregator. It takes two or more value nodes as an input
 * and outputs a sum of values outputted by those nodes.
 */
/*package*/ class AdditionAnimatedNode extends ValueAnimatedNode {

  private final NativeAnimatedNodesManager mNativeAnimatedNodesManager;
  private final int[] mInputNodes;

  public AdditionAnimatedNode(
      ReadableMap config,
      NativeAnimatedNodesManager nativeAnimatedNodesManager) {
    mNativeAnimatedNodesManager = nativeAnimatedNodesManager;
    ReadableArray inputNodes = config.getArray("input");
    mInputNodes = new int[inputNodes.size()];
    for (int i = 0; i < mInputNodes.length; i++) {
      mInputNodes[i] = inputNodes.getInt(i);
    }
  }

  @Override
  public void update() {
    mValue = 0;
    for (int i = 0; i < mInputNodes.length; i++) {
      AnimatedNode animatedNode = mNativeAnimatedNodesManager.getNodeById(mInputNodes[i]);
      if (animatedNode != null && animatedNode instanceof ValueAnimatedNode) {
        mValue += ((ValueAnimatedNode) animatedNode).mValue;
      } else {
        throw new JSApplicationCausedNativeException("Illegal node ID set as an input for " +
          "Animated.Add node");
      }
    }
  }
}