Stop native driver animations when value is set.

Summary:
This diff changes the behaviour of natively driven animations in case the node that they are being run for has its value changed using `setValue` or as a result of an incoming event.

The reason for changing that is to match the JS implementation of `setValue` which behaves as described above (see relevant code here: 7cdd4d48c8/Libraries/Animated/src/AnimatedImplementation.js (L743))

**Test Plan:**
Use this sample app: https://snack.expo.io/B1V7RX9r-
Change: `USE_NATIVE_DRIVER` const between `true` and `false`.
See the animation stops regardless of the state of `USE_NATIVE_DRIVER` unlike before when it would stop only when `USE_NATIVE_DRIVER` was set to `false`
Closes https://github.com/facebook/react-native/pull/15054

Differential Revision: D5463750

Pulled By: hramos

fbshipit-source-id: e164c5299588ba8cac2937260c9ba9f6053b04e5

Libraries/NativeAnimation/RCTNativeAnimatedNodesManager.m

@@ -170,6 +170,7 @@
     RCTLogError(@"Not a value node.");
     return;
   }
+  [self stopAnimationsForNode:node];
 
   RCTValueAnimatedNode *valueNode = (RCTValueAnimatedNode *)node;
   valueNode.value = value.floatValue;
@@ -264,6 +265,20 @@
   }
 }
 
+- (void)stopAnimationsForNode:(nonnull RCTAnimatedNode *)node
+{
+    NSMutableArray<id<RCTAnimationDriver>> *discarded = [NSMutableArray new];
+    for (id<RCTAnimationDriver> driver in _activeAnimations) {
+        if ([driver.valueNode isEqual:node]) {
+            [discarded addObject:driver];
+        }
+    }
+    for (id<RCTAnimationDriver> driver in discarded) {
+        [driver stopAnimation];
+        [_activeAnimations removeObject:driver];
+    }
+}
+
 #pragma mark -- Events
 
 - (void)addAnimatedEventToView:(nonnull NSNumber *)viewTag
@@ -328,6 +343,7 @@
   NSMutableArray<RCTEventAnimation *> *driversForKey = _eventDrivers[key];
   if (driversForKey) {
     for (RCTEventAnimation *driver in driversForKey) {
+      [self stopAnimationsForNode:driver.valueNode];
       [driver updateWithEvent:event];
     }
 

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

@@ -29,7 +29,6 @@ import com.facebook.react.uimanager.events.EventDispatcherListener;
 
 import java.util.ArrayDeque;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
@@ -145,6 +144,7 @@ import javax.annotation.Nullable;
       throw new JSApplicationIllegalArgumentException("Animated node with tag " + tag +
         " does not exists or is not a 'value' node");
     }
+    stopAnimationsForNode(node);
     ((ValueAnimatedNode) node).mValue = value;
     mUpdatedNodes.put(tag, node);
   }
@@ -208,6 +208,24 @@ import javax.annotation.Nullable;
     mActiveAnimations.put(animationId, animation);
   }
 
+  private void stopAnimationsForNode(AnimatedNode animatedNode) {
+    // in most of the cases there should never be more than a few active animations running at the
+    // same time. Therefore it does not make much sense to create an animationId -> animation
+    // object map that would require additional memory just to support the use-case of stopping
+    // an animation
+    for (int i = 0; i < mActiveAnimations.size(); i++) {
+      AnimationDriver animation = mActiveAnimations.valueAt(i);
+      if (animatedNode.equals(animation.mAnimatedValue)) {
+        // Invoke animation end callback with {finished: false}
+        WritableMap endCallbackResponse = Arguments.createMap();
+        endCallbackResponse.putBoolean("finished", false);
+        animation.mEndCallback.invoke(endCallbackResponse);
+        mActiveAnimations.removeAt(i);
+        i--;
+      }
+    }
+  }
+
   public void stopAnimation(int animationId) {
     // in most of the cases there should never be more than a few active animations running at the
     // same time. Therefore it does not make much sense to create an animationId -> animation
@@ -362,6 +380,7 @@ import javax.annotation.Nullable;
       List<EventAnimationDriver> driversForKey = mEventDrivers.get(event.getViewTag() + eventName);
       if (driversForKey != null) {
         for (EventAnimationDriver driver : driversForKey) {
+          stopAnimationsForNode(driver.mValueNode);
           event.dispatch(driver);
           mRunUpdateNodeList.add(driver.mValueNode);
         }