Disable accessibility if all accessibility serivces are disbaled.

Accessibility was kept enabled even if all accessibility services
are disabled (explicitly by the user or removed) which was causing
the system to fire accessibility events that will never be consumed.

Change-Id: Ifb03e786ac0106687252bd1979725ffd724ad1c5

Author: sganov

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

@@ -225,7 +225,7 @@ public boolean onHandleForceStop(Intent intent, String[] packages,
                     return false;
                 }
             }
-            
+
             @Override
             public void onReceive(Context context, Intent intent) {
                 if (intent.getAction() == Intent.ACTION_BOOT_COMPLETED) {
@@ -697,6 +697,7 @@ private boolean canDispathEventLocked(Service service, AccessibilityEvent event,
     private void manageServicesLocked() {
         populateEnabledServicesLocked(mEnabledServices);
         updateServicesStateLocked(mInstalledServices, mEnabledServices);
+        disableAccessibilityIfNoEnabledServices(mEnabledServices);
     }
 
     /**
@@ -780,6 +781,19 @@ private void updateServicesStateLocked(List<AccessibilityServiceInfo> installedS
         }
     }
 
+    /**
+     * Disables accessibility if there are no enabled accessibility services which
+     * to consume the generated accessibility events.
+     *
+     * @param enabledServices The set of enabled services.
+     */
+    private void disableAccessibilityIfNoEnabledServices(Set<ComponentName> enabledServices) {
+        if (enabledServices.isEmpty()) {
+            Settings.Secure.putInt(mContext.getContentResolver(),
+                    Settings.Secure.ACCESSIBILITY_ENABLED, 0);
+        }
+    }
+
     /**
      * Sends the state to the clients.
      */