Support for Animated.multiply node

Summary:This change adds native animated support for Animated.multiply nodes.

Animated.multiply allows for defining nodes that would output a product of values of the input nodes.

**Test Plan**
Run JS tests: `npm test Libraries/Animated/src/__tests__/AnimatedNative-test.js`
Run java tests: `buck test ReactAndroid/src/test/java/com/facebook/react/animated`
Closes https://github.com/facebook/react-native/pull/7071

Differential Revision: D3197663

fb-gh-sync-id: 35f64244a2482c487a81e5e7cd08f3c0e56d9b78
fbshipit-source-id: 35f64244a2482c487a81e5e7cd08f3c0e56d9b78

Libraries/Animated/src/AnimatedImplementation.js

@@ -995,6 +995,12 @@ class AnimatedMultiplication extends AnimatedWithChildren {
     this._b = typeof b === 'number' ? new AnimatedValue(b) : b;
   }
 
+  __makeNative() {
+    super.__makeNative();
+    this._a.__makeNative();
+    this._b.__makeNative();
+  }
+
   __getValue(): number {
     return this._a.__getValue() * this._b.__getValue();
   }
@@ -1011,6 +1017,14 @@ class AnimatedMultiplication extends AnimatedWithChildren {
   __detach(): void {
     this._a.__removeChild(this);
     this._b.__removeChild(this);
+    super.__detach();
+  }
+
+  __getNativeConfig(): any {
+    return {
+      type: 'multiplication',
+      input: [this._a.__getNativeTag(), this._b.__getNativeTag()],
+    };
   }
 }
 

Libraries/Animated/src/__tests__/AnimatedNative-test.js

@@ -124,6 +124,40 @@ describe('Animated', () => {
       .toBeCalledWith(additionCall[1].input[1], { type: 'value', value: 2 });
   });
 
+  it('sends a valid graph description for Animated.multiply nodes', () => {
+    var first = new Animated.Value(2);
+    var second = new Animated.Value(1);
+
+    var c = new Animated.View();
+    c.props = {
+      style: {
+        opacity: Animated.multiply(first, second),
+      },
+    };
+    c.componentWillMount();
+
+    Animated.timing(first, {toValue: 5, duration: 1000, useNativeDriver: true}).start();
+    Animated.timing(second, {toValue: -1, duration: 1000, useNativeDriver: true}).start();
+
+    var nativeAnimatedModule = require('NativeModules').NativeAnimatedModule;
+    expect(nativeAnimatedModule.createAnimatedNode)
+      .toBeCalledWith(jasmine.any(Number), { type: 'multiplication', input: jasmine.any(Array) });
+    var multiplicationCalls = nativeAnimatedModule.createAnimatedNode.mock.calls.filter(
+      (call) => call[1].type === 'multiplication'
+    );
+    expect(multiplicationCalls.length).toBe(1);
+    var multiplicationCall = multiplicationCalls[0];
+    var multiplicationNodeTag = multiplicationCall[0];
+    var multiplicationConnectionCalls = nativeAnimatedModule.connectAnimatedNodes.mock.calls.filter(
+      (call) => call[1] === multiplicationNodeTag
+    );
+    expect(multiplicationConnectionCalls.length).toBe(2);
+    expect(nativeAnimatedModule.createAnimatedNode)
+      .toBeCalledWith(multiplicationCall[1].input[0], { type: 'value', value: 2 });
+    expect(nativeAnimatedModule.createAnimatedNode)
+      .toBeCalledWith(multiplicationCall[1].input[1], { type: 'value', value: 1 });
+  });
+
   it('sends a valid timing animation description', () => {
     var anim = new Animated.Value(0);
     Animated.timing(anim, {toValue: 10, duration: 1000, useNativeDriver: true}).start();

ReactAndroid/src/main/java/com/facebook/react/animated/MultiplicationAnimatedNode.java

@@ -0,0 +1,40 @@
+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 which takes two or more value node as an input and outputs a product of their
+ * values
+ */
+/*package*/ class MultiplicationAnimatedNode extends ValueAnimatedNode {
+
+  private final NativeAnimatedNodesManager mNativeAnimatedNodesManager;
+  private final int[] mInputNodes;
+
+  public MultiplicationAnimatedNode(
+      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 = 1;
+    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.multiply node");
+      }
+    }
+  }
+}

ReactAndroid/src/main/java/com/facebook/react/animated/NativeAnimatedNodesManager.java

@@ -74,6 +74,8 @@ import javax.annotation.Nullable;
       node = new PropsAnimatedNode(config, this);
     } else if ("addition".equals(type)) {
       node = new AdditionAnimatedNode(config, this);
+    } else if ("multiplication".equals(type)) {
+      node = new MultiplicationAnimatedNode(config, this);
     } else {
       throw new JSApplicationIllegalArgumentException("Unsupported node type: " + type);
     }

ReactAndroid/src/test/java/com/facebook/react/animated/NativeAnimatedNodeTraversalTest.java

@@ -341,4 +341,64 @@ public class NativeAnimatedNodeTraversalTest {
     mNativeAnimatedNodesManager.runUpdates(nextFrameTime());
     verifyNoMoreInteractions(mUIImplementationMock);
   }
+
+  @Test
+  public void testMultiplicationNode() {
+    mNativeAnimatedNodesManager.createAnimatedNode(
+      1,
+      JavaOnlyMap.of("type", "value", "value", 1d));
+    mNativeAnimatedNodesManager.createAnimatedNode(
+      2,
+      JavaOnlyMap.of("type", "value", "value", 5d));
+
+    mNativeAnimatedNodesManager.createAnimatedNode(
+      3,
+      JavaOnlyMap.of("type", "multiplication", "input", JavaOnlyArray.of(1, 2)));
+
+    mNativeAnimatedNodesManager.createAnimatedNode(
+      4,
+      JavaOnlyMap.of("type", "style", "style", JavaOnlyMap.of("translateX", 3)));
+    mNativeAnimatedNodesManager.createAnimatedNode(
+      5,
+      JavaOnlyMap.of("type", "props", "props", JavaOnlyMap.of("style", 4)));
+    mNativeAnimatedNodesManager.connectAnimatedNodes(1, 3);
+    mNativeAnimatedNodesManager.connectAnimatedNodes(2, 3);
+    mNativeAnimatedNodesManager.connectAnimatedNodes(3, 4);
+    mNativeAnimatedNodesManager.connectAnimatedNodes(4, 5);
+    mNativeAnimatedNodesManager.connectAnimatedNodeToView(5, 50);
+
+    Callback animationCallback = mock(Callback.class);
+    JavaOnlyArray frames = JavaOnlyArray.of(0d, 1d);
+    mNativeAnimatedNodesManager.startAnimatingNode(
+      1,
+      JavaOnlyMap.of("type", "frames", "frames", frames, "toValue", 2d),
+      animationCallback);
+
+    mNativeAnimatedNodesManager.startAnimatingNode(
+      2,
+      JavaOnlyMap.of("type", "frames", "frames", frames, "toValue", 10d),
+      animationCallback);
+
+    ArgumentCaptor<ReactStylesDiffMap> stylesCaptor =
+      ArgumentCaptor.forClass(ReactStylesDiffMap.class);
+
+    reset(mUIImplementationMock);
+    mNativeAnimatedNodesManager.runUpdates(nextFrameTime());
+    verify(mUIImplementationMock).synchronouslyUpdateViewOnUIThread(eq(50), stylesCaptor.capture());
+    assertThat(stylesCaptor.getValue().getDouble("translateX", Double.NaN)).isEqualTo(5d);
+
+    reset(mUIImplementationMock);
+    mNativeAnimatedNodesManager.runUpdates(nextFrameTime());
+    verify(mUIImplementationMock).synchronouslyUpdateViewOnUIThread(eq(50), stylesCaptor.capture());
+    assertThat(stylesCaptor.getValue().getDouble("translateX", Double.NaN)).isEqualTo(5d);
+
+    reset(mUIImplementationMock);
+    mNativeAnimatedNodesManager.runUpdates(nextFrameTime());
+    verify(mUIImplementationMock).synchronouslyUpdateViewOnUIThread(eq(50), stylesCaptor.capture());
+    assertThat(stylesCaptor.getValue().getDouble("translateX", Double.NaN)).isEqualTo(20d);
+
+    reset(mUIImplementationMock);
+    mNativeAnimatedNodesManager.runUpdates(nextFrameTime());
+    verifyNoMoreInteractions(mUIImplementationMock);
+  }
 }