Polish user selector accessibility.

1. The current user was not announced as such.

2. The event for a user switch was not sent.

Change-Id: Ib3caf1f9e93ea1f0b5450246601bc37f416be6da

core/java/android/view/accessibility/AccessibilityRecord.java

@@ -167,6 +167,17 @@ public class AccessibilityRecord {
                 mSourceNodeId, GET_SOURCE_PREFETCH_FLAGS);
     }
 
+    /**
+     * Sets the window id.
+     *
+     * @param windowId The window id.
+     *
+     * @hide
+     */
+    public void setWindowId(int windowId) {
+        mSourceWindowId = windowId;
+    }
+
     /**
      * Gets the id of the window from which the event comes from.
      *

policy/src/com/android/internal/policy/impl/keyguard/KeyguardMultiUserAvatar.java

@@ -150,6 +150,11 @@ class KeyguardMultiUserAvatar extends FrameLayout {
             if (active) {
                 KeyguardLinearLayout parent = (KeyguardLinearLayout) getParent();
                 parent.setTopChild(this);
+                // TODO: Create an appropriate asset when string changes are possible.
+                setContentDescription(mUserName.getText()
+                        + ". " + mContext.getString(R.string.user_switched, ""));
+            } else {
+                setContentDescription(mUserName.getText());
             }
         }
         updateVisualsForActive(mActive, animate, SWITCH_ANIMATION_DURATION, onComplete);

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

@@ -1330,6 +1330,7 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub {
                     AccessibilityEvent event = AccessibilityEvent.obtain(
                             AccessibilityEvent.TYPE_ANNOUNCEMENT);
                     event.getText().add(message);
+                    event.setWindowId(mSecurityPolicy.getRetrievalAllowingWindowLocked());
                     sendAccessibilityEvent(event, mCurrentUserId);
                 }
             }