From e95e73aaa7a06500e7db961613d5edb8ecf3d0d7 Mon Sep 17 00:00:00 2001
From: David Vacca <dvacca@fb.com>
Date: Tue, 5 Jun 2018 13:12:59 -0700
Subject: [PATCH] Fix events not working after closing and navigating back to
 Fabric screen in FB4A

Reviewed By: fkgozali

Differential Revision: D8240344

fbshipit-source-id: 992945f94843589cefdf7ea24da709449ee38778
---
 .../facebook/react/fabric/FabricUIManager.java  |  7 ++++++-
 .../react/uimanager/events/EventDispatcher.java |  5 ++++-
 .../uimanager/events/ReactEventEmitter.java     | 17 ++++-------------
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java b/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java
index 0a35242d1..91098711e 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java
@@ -66,6 +66,7 @@ public class FabricUIManager implements UIManager, JSHandler {
   private final FabricReconciler mFabricReconciler;
   private final EventDispatcher mEventDispatcher;
   private FabricBinding mBinding;
+  private final FabricEventEmitter mFabricEventEmitter;
   private long mEventHandlerPointer;
 
   public FabricUIManager(
@@ -81,6 +82,8 @@ public class FabricUIManager implements UIManager, JSHandler {
         new UIViewOperationQueue(
             reactContext, mNativeViewHierarchyManager, 0);
     mFabricReconciler = new FabricReconciler(mUIViewOperationQueue);
+    mFabricEventEmitter =
+      new FabricEventEmitter(mReactApplicationContext, this);
     mEventDispatcher = eventDispatcher;
     mJSContext = jsContext;
   }
@@ -537,12 +540,14 @@ public class FabricUIManager implements UIManager, JSHandler {
   public void initialize() {
     FabricEventEmitter eventEmitter =
       new FabricEventEmitter(mReactApplicationContext, this);
-    mEventDispatcher.registerEventEmitter(FABRIC, eventEmitter);
+    mEventDispatcher.registerEventEmitter(FABRIC, mFabricEventEmitter);
   }
 
   @Override
   public void onCatalystInstanceDestroy() {
     mBinding.releaseEventHandler(mJSContext.get(), mEventHandlerPointer);
+    mEventDispatcher.unregisterEventEmitter(FABRIC);
+    mFabricEventEmitter.close();
   }
 
 }
diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/EventDispatcher.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/EventDispatcher.java
index cd8b44eb9..d983eebeb 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/EventDispatcher.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/EventDispatcher.java
@@ -161,7 +161,6 @@ public class EventDispatcher implements LifecycleEventListener {
   @Override
   public void onHostDestroy() {
     stopFrameCallback();
-    mReactEventEmitter.stop();
   }
 
   public void onCatalystInstanceDestroyed() {
@@ -254,6 +253,10 @@ public class EventDispatcher implements LifecycleEventListener {
     mReactEventEmitter.register(uiManagerType, eventEmitter);
   }
 
+  public void unregisterEventEmitter(@UIManagerType int uiManagerType) {
+    mReactEventEmitter.unregister(uiManagerType);
+  }
+
   private class ScheduleDispatchFrameCallback extends ChoreographerCompat.FrameCallback {
     private volatile boolean mIsPosted = false;
     private boolean mShouldStop = false;
diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/ReactEventEmitter.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/ReactEventEmitter.java
index c54af2212..5d07b3564 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/ReactEventEmitter.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/ReactEventEmitter.java
@@ -31,6 +31,10 @@ public class ReactEventEmitter implements RCTEventEmitter {
     mEventEmitters.put(uiManagerType, eventEmitter);
   }
 
+  public void unregister(@UIManagerType int uiManagerType) {
+    mEventEmitters.remove(uiManagerType);
+  }
+
   @Override
   public void receiveEvent(int targetReactTag, String eventName, @Nullable WritableMap event) {
     getEventEmitter(targetReactTag).receiveEvent(targetReactTag, eventName, event);
@@ -52,17 +56,4 @@ public class ReactEventEmitter implements RCTEventEmitter {
     int type = ViewUtil.getUIManagerType(reactTag);
     return mEventEmitters.get(type);
   }
-
-  public void stop() {
-    for (int i = 0 ; i < mEventEmitters.size() ; i++) {
-      RCTEventEmitter eventEmitter = mEventEmitters.valueAt(i);
-      if (eventEmitter instanceof Closeable) {
-        try {
-          ((Closeable) eventEmitter).close();
-        } catch (IOException e) {
-          Log.i(TAG, "Exception when closing EventEmitter: " + eventEmitter, e);
-        }
-      }
-    }
-  }
 }