From ccef1b29411dd7c639261154220892135bc9bd06 Mon Sep 17 00:00:00 2001
From: Dave Miller <dmmiller@fb.com>
Date: Mon, 16 May 2016 02:33:50 -0700
Subject: [PATCH] More touch logging

Reviewed By: andreicoman11

Differential Revision: D3298518

fbshipit-source-id: 0ddbba5c05848ac164f6f1562b26609924978169
---
 .../facebook/react/uimanager/JSTouchDispatcher.java    | 10 +++++++++-
 .../events/TouchEventCoalescingKeyHelper.java          |  8 ++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/JSTouchDispatcher.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/JSTouchDispatcher.java
index fefab066f..a5d7056ce 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/JSTouchDispatcher.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/JSTouchDispatcher.java
@@ -18,6 +18,7 @@ import com.facebook.react.common.ReactConstants;
 import com.facebook.react.common.SystemClock;
 import com.facebook.react.uimanager.events.EventDispatcher;
 import com.facebook.react.uimanager.events.TouchEvent;
+import com.facebook.react.uimanager.events.TouchEventCoalescingKeyHelper;
 import com.facebook.react.uimanager.events.TouchEventType;
 
 /**
@@ -137,7 +138,14 @@ public class JSTouchDispatcher {
           mTargetCoordinates[0],
           mTargetCoordinates[1]));
     } else if (action == MotionEvent.ACTION_CANCEL) {
-      dispatchCancelEvent(ev, eventDispatcher);
+      if (TouchEventCoalescingKeyHelper.hasCoalescingKey(ev.getDownTime())) {
+        dispatchCancelEvent(ev, eventDispatcher);
+      } else {
+        FLog.e(
+          ReactConstants.TAG,
+          "Received an ACTION_CANCEL touch event for which we have no corresponding ACTION_DOWN"
+        );
+      }
       mTargetTag = -1;
     } else {
       FLog.w(
diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/TouchEventCoalescingKeyHelper.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/TouchEventCoalescingKeyHelper.java
index e5783e3c5..acc2d3afa 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/TouchEventCoalescingKeyHelper.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/TouchEventCoalescingKeyHelper.java
@@ -83,4 +83,12 @@ public class TouchEventCoalescingKeyHelper {
   public static void removeCoalescingKey(long downTime) {
     sDownTimeToCoalescingKey.delete((int) downTime);
   }
+
+  public static boolean hasCoalescingKey(long downTime) {
+    int currentValue = sDownTimeToCoalescingKey.get((int) downTime, -1);
+    if (currentValue == -1) {
+      return false;
+    }
+    return true;
+  }
 }