NLS: Add a public signal value for an undefined filter value.

We have three possible defined values for getInterruptionFilter().
i.e. All/Priority/None.

However, this value is only returned to listeners once connected,
otherwise we return 0, an undefined value.

This change gives a name to this undefined value to make it clear
that callers should not infer any meaning from it.

INTERRUPTION_FILTER_UNKNOWN = 0;

Bug: 19288429
Change-Id: I8ae94d1723289ca5714800906f9bf4e7e8111813

1 files changed, 12 insertions, 3 deletions

diff --git a/core/java/android/service/notification/NotificationListenerService.java b/core/java/android/service/notification/NotificationListenerService.java
index 3d39b18..0860153 100644
--- a/core/java/android/service/notification/NotificationListenerService.java
+++ b/core/java/android/service/notification/NotificationListenerService.java
@@ -77,6 +77,14 @@ public abstract class NotificationListenerService extends Service {
      */
     public static final int INTERRUPTION_FILTER_NONE = 3;
 
+    /** {@link #getCurrentInterruptionFilter() Interruption filter} constant - returned when
+     * the value is unavailable for any reason.  For example, before the notification listener
+     * is connected.
+     *
+     * {@see #onListenerConnected()}
+     */
+    public static final int INTERRUPTION_FILTER_UNKNOWN = 0;
+
     /** {@link #getCurrentListenerHints() Listener hints} constant - the primary device UI
      * should disable notification sound, vibrating and other visual or aural effects.
      * This does not change the interruption filter, only the effects. **/
@@ -473,15 +481,16 @@ public abstract class NotificationListenerService extends Service {
      * <p>
      * Listen for updates using {@link #onInterruptionFilterChanged(int)}.
      *
-     * @return One of the INTERRUPTION_FILTER_ constants, or 0 on errors.
+     * @return One of the INTERRUPTION_FILTER_ constants, or INTERRUPTION_FILTER_UNKNOWN when
+     * unavailable.
      */
     public final int getCurrentInterruptionFilter() {
-        if (!isBound()) return 0;
+        if (!isBound()) return INTERRUPTION_FILTER_UNKNOWN;
         try {
             return getNotificationInterface().getInterruptionFilterFromListener(mWrapper);
         } catch (android.os.RemoteException ex) {
             Log.v(TAG, "Unable to contact notification manager", ex);
-            return 0;
+            return INTERRUPTION_FILTER_UNKNOWN;
         }
     }