Native Animated - Support events using RCT{Direct|Bubbling}EventBlock on iOS (#15611)

Summary:
When calling a prop of type `RCTDirectEventBlock` or `RCTBubblingEventBlock` it uses a completely different code path than events using `[RCTEventDispatcher sendEvent:]` and those were not dispatched to the `RCTEventDispatcherListener`s. We also do some event name normalization which caused issues between the JS and native event names. To fix that I simply remove the parts we normalize from the event key.

## Changelog:

[iOS] [Fixed] - Support events using RCT{Direct|Bubbling}EventBlock
Pull Request resolved: https://github.com/facebook/react-native/pull/15611

Test Plan: Added a Slider (it used RCTBubblingEventBlock for it's onValueChange event) that can control a native animated value in RNTester to reproduce the bug and made sure this diff fixes it.

Differential Revision: D15896806

Pulled By: cpojer

fbshipit-source-id: c0ae463f4c3f890062238575e813ed7ab3b7a7e6

Libraries/NativeAnimation/RCTNativeAnimatedNodesManager.m

@@ -28,6 +28,21 @@
 #import "RCTValueAnimatedNode.h"
 #import "RCTTrackingAnimatedNode.h"
 
+// We do some normalizing of the event names in RCTEventDispatcher#RCTNormalizeInputEventName.
+// To make things simpler just get rid of the parts we change in the event names we use here.
+// This is a lot easier than trying to denormalize because there would be multiple possible
+// denormalized forms for a single input.
+NSString *RCTNormalizeAnimatedEventName(NSString *eventName)
+{
+  if ([eventName hasPrefix:@"on"]) {
+    return [eventName substringFromIndex:2];
+  }
+  if ([eventName hasPrefix:@"top"]) {
+    return [eventName substringFromIndex:3];
+  }
+  return eventName;
+}
+
 @implementation RCTNativeAnimatedNodesManager
 {
   __weak RCTBridge *_bridge;
@@ -321,7 +336,7 @@
   RCTEventAnimation *driver =
     [[RCTEventAnimation alloc] initWithEventPath:eventPath valueNode:(RCTValueAnimatedNode *)node];
 
-  NSString *key = [NSString stringWithFormat:@"%@%@", viewTag, eventName];
+  NSString *key = [NSString stringWithFormat:@"%@%@", viewTag, RCTNormalizeAnimatedEventName(eventName)];
   if (_eventDrivers[key] != nil) {
     [_eventDrivers[key] addObject:driver];
   } else {
@@ -335,7 +350,7 @@
                           eventName:(nonnull NSString *)eventName
                     animatedNodeTag:(nonnull NSNumber *)animatedNodeTag
 {
-  NSString *key = [NSString stringWithFormat:@"%@%@", viewTag, eventName];
+  NSString *key = [NSString stringWithFormat:@"%@%@", viewTag, RCTNormalizeAnimatedEventName(eventName)];
   if (_eventDrivers[key] != nil) {
     if (_eventDrivers[key].count == 1) {
       [_eventDrivers removeObjectForKey:key];
@@ -357,7 +372,7 @@
     return;
   }
 
-  NSString *key = [NSString stringWithFormat:@"%@%@", event.viewTag, event.eventName];
+  NSString *key = [NSString stringWithFormat:@"%@%@", event.viewTag, RCTNormalizeAnimatedEventName(event.eventName)];
   NSMutableArray<RCTEventAnimation *> *driversForKey = _eventDrivers[key];
   if (driversForKey) {
     for (RCTEventAnimation *driver in driversForKey) {

RNTester/js/examples/NativeAnimation/NativeAnimationsExample.js

@@ -221,7 +221,7 @@ class InternalSettings extends React.Component<
 
 class EventExample extends React.Component<{}, $FlowFixMeState> {
   state = {
-    scrollX: new Animated.Value(0),
+    anim: new Animated.Value(0),
   };
 
   render() {
@@ -233,7 +233,7 @@ class EventExample extends React.Component<{}, $FlowFixMeState> {
             {
               transform: [
                 {
-                  rotate: this.state.scrollX.interpolate({
+                  rotate: this.state.anim.interpolate({
                     inputRange: [0, 1],
                     outputRange: ['0deg', '1deg'],
                   }),
@@ -246,7 +246,7 @@ class EventExample extends React.Component<{}, $FlowFixMeState> {
           horizontal
           style={{height: 100, marginTop: 16}}
           onScroll={Animated.event(
-            [{nativeEvent: {contentOffset: {x: this.state.scrollX}}}],
+            [{nativeEvent: {contentOffset: {x: this.state.anim}}}],
             {useNativeDriver: true},
           )}>
           <View
@@ -259,6 +259,13 @@ class EventExample extends React.Component<{}, $FlowFixMeState> {
             <Text>Scroll me sideways!</Text>
           </View>
         </Animated.ScrollView>
+        <AnimatedSlider
+          maximumValue={200}
+          onValueChange={Animated.event(
+            [{nativeEvent: {value: this.state.anim}}],
+            {useNativeDriver: true},
+          )}
+        />
       </View>
     );
   }