Synchronizing invalidating interaction handler with the eventQueue.

In some cases, eventQueue could be running on the background thread where as
the invalidate happens on the UI thread, which could cause race conditions in
touch consumer

Change-Id: Iebd84238eb2b5d6774beaa3bc21afdeb09e62561

4 files changed, 10 insertions, 15 deletions

diff --git a/quickstep/src/com/android/quickstep/BaseSwipeInteractionHandler.java b/quickstep/src/com/android/quickstep/BaseSwipeInteractionHandler.java
index 5bf7e4ec9..b3ebd772c 100644
--- a/quickstep/src/com/android/quickstep/BaseSwipeInteractionHandler.java
+++ b/quickstep/src/com/android/quickstep/BaseSwipeInteractionHandler.java
@@ -20,13 +20,11 @@ import android.support.annotation.WorkerThread;
 import com.android.launcher3.states.InternalStateHandler;
 import com.android.quickstep.TouchConsumer.InteractionType;
 
-import java.util.function.Consumer;
-
 public abstract class BaseSwipeInteractionHandler extends InternalStateHandler {
 
-    protected Consumer<BaseSwipeInteractionHandler> mGestureEndCallback;
+    protected Runnable mGestureEndCallback;
 
-    public void setGestureEndCallback(Consumer<BaseSwipeInteractionHandler> gestureEndCallback) {
+    public void setGestureEndCallback(Runnable gestureEndCallback) {
         mGestureEndCallback = gestureEndCallback;
     }
 
diff --git a/quickstep/src/com/android/quickstep/NavBarSwipeInteractionHandler.java b/quickstep/src/com/android/quickstep/NavBarSwipeInteractionHandler.java
index ae70474c0..ff7d434e7 100644
--- a/quickstep/src/com/android/quickstep/NavBarSwipeInteractionHandler.java
+++ b/quickstep/src/com/android/quickstep/NavBarSwipeInteractionHandler.java
@@ -347,7 +347,7 @@ public class NavBarSwipeInteractionHandler extends BaseSwipeInteractionHandler i
     public void reset() {
         mCurrentShift.cancelAnimation();
         if (mGestureEndCallback != null) {
-            mGestureEndCallback.accept(this);
+            mGestureEndCallback.run();
         }
     }
 
diff --git a/quickstep/src/com/android/quickstep/OtherActivityTouchConsumer.java b/quickstep/src/com/android/quickstep/OtherActivityTouchConsumer.java
index 604b60b90..786ade38b 100644
--- a/quickstep/src/com/android/quickstep/OtherActivityTouchConsumer.java
+++ b/quickstep/src/com/android/quickstep/OtherActivityTouchConsumer.java
@@ -230,6 +230,9 @@ public class OtherActivityTouchConsumer extends ContextWrapper implements TouchC
     }
 
     private void notifyGestureStarted() {
+        if (mInteractionHandler == null) {
+            return;
+        }
         // Notify the handler that the gesture has actually started
         mInteractionHandler.onGestureStarted();
 
@@ -275,7 +278,7 @@ public class OtherActivityTouchConsumer extends ContextWrapper implements TouchC
         // Preload the plan
         mRecentsModel.loadTasks(mRunningTask.id, null);
         mInteractionHandler = handler;
-        mInteractionHandler.setGestureEndCallback(this::onFinish);
+        mInteractionHandler.setGestureEndCallback(mEventQueue::reset);
     }
 
     private Bitmap getCurrentTaskSnapshot() {
@@ -314,7 +317,7 @@ public class OtherActivityTouchConsumer extends ContextWrapper implements TouchC
         // Preload the plan
         mRecentsModel.loadTasks(mRunningTask.id, null);
         mInteractionHandler = handler;
-        handler.setGestureEndCallback(this::onFinish);
+        handler.setGestureEndCallback(mEventQueue::reset);
 
         CountDownLatch drawWaitLock = new CountDownLatch(1);
         handler.setLauncherOnDrawCallback(() -> {
@@ -408,8 +411,8 @@ public class OtherActivityTouchConsumer extends ContextWrapper implements TouchC
         // Clean up the old interaction handler
         if (mInteractionHandler != null) {
             final BaseSwipeInteractionHandler handler = mInteractionHandler;
-            mMainThreadExecutor.execute(handler::reset);
             mInteractionHandler = null;
+            mMainThreadExecutor.execute(handler::reset);
         }
     }
 
@@ -450,12 +453,6 @@ public class OtherActivityTouchConsumer extends ContextWrapper implements TouchC
         }
     }
 
-    private void onFinish(BaseSwipeInteractionHandler handler) {
-        if (mInteractionHandler == handler) {
-            mInteractionHandler = null;
-        }
-    }
-
     public void switchToMainChoreographer() {
         mEventQueue.setInterimChoreographer(null);
     }
diff --git a/quickstep/src/com/android/quickstep/WindowTransformSwipeHandler.java b/quickstep/src/com/android/quickstep/WindowTransformSwipeHandler.java
index ac253c70d..a6192c2f5 100644
--- a/quickstep/src/com/android/quickstep/WindowTransformSwipeHandler.java
+++ b/quickstep/src/com/android/quickstep/WindowTransformSwipeHandler.java
@@ -688,7 +688,7 @@ public class WindowTransformSwipeHandler extends BaseSwipeInteractionHandler {
         mCurrentShift.cancelAnimation();
 
         if (mGestureEndCallback != null) {
-            mGestureEndCallback.accept(this);
+            mGestureEndCallback.run();
         }
 
         clearReference();