The active window for accessibility purposes can be miscomputed.

1. The active window is the one that the user touches or the one
   that has input focus. We recognize the user touching a window
   by the received accessibility hover events and the user not
   touching the screen by a call from the touch explorer. It is
   possible that the user touches window that does not have
   input focus and as soon as he lifts finger the active one
   will become the window that has input focus but now we get
   he hover accessibility events from the touched window which
   incorrectly changes the active window to be the touched one.
   Note that at this point the user is not touching the screen.

bug:7298484

Change-Id: Ife035a798a6e68133f9220eeeabdfcd35a431b56

Author: sganov

services/java/com/android/server/accessibility/AccessibilityManagerService.java

@@ -643,6 +643,10 @@ int getActiveWindowId() {
         return mSecurityPolicy.mActiveWindowId;
     }
 
+    void onTouchInteractionStart() {
+        mSecurityPolicy.onTouchInteractionStart();
+    }
+
     void onTouchInteractionEnd() {
         mSecurityPolicy.onTouchInteractionEnd();
     }
@@ -2138,6 +2142,7 @@ final class SecurityPolicy {
             | AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED;
 
         private int mActiveWindowId;
+        private boolean mTouchInteractionInProgress;
 
         private boolean canDispatchAccessibilityEvent(AccessibilityEvent event) {
             final int eventType = event.getEventType();
@@ -2185,12 +2190,21 @@ public void updateActiveWindow(int windowId, int eventType) {
                     }
                 } break;
                 case AccessibilityEvent.TYPE_VIEW_HOVER_ENTER: {
-                    mActiveWindowId = windowId;
+                    // Do not allow delayed hover events to confuse us
+                    // which the active window is.
+                    if (mTouchInteractionInProgress) {
+                        mActiveWindowId = windowId;
+                    }
                 } break;
             }
         }
 
+        public void onTouchInteractionStart() {
+            mTouchInteractionInProgress = true;
+        }
+
         public void onTouchInteractionEnd() {
+            mTouchInteractionInProgress = false;
             // We want to set the active window to be current immediately
             // after the user has stopped touching the screen since if the
             // user types with the IME he should get a feedback for the

services/java/com/android/server/accessibility/TouchExplorer.java

@@ -398,6 +398,7 @@ private void handleMotionEventStateTouchExploring(MotionEvent event, MotionEvent
 
         switch (event.getActionMasked()) {
             case MotionEvent.ACTION_DOWN:
+                mAms.onTouchInteractionStart();
                 // Pre-feed the motion events to the gesture detector since we
                 // have a distance slop before getting into gesture detection
                 // mode and not using the points within this slop significantly