commit fc1f7ab8ad2f6c01b804cdf41097766a30c89ca9
author Jaewan Kim <jaewan@google.com> Thu Mar 30 03:22:03 2017 +0900
committer Jaewan Kim <jaewan@google.com> Wed Apr 19 05:53:23 2017 +0000
tree 0b18e2b3c7f2ee89cf033d9a5ba822d52da8bf55
parent fe1bddfbb54c20156b45e99c9d18166d702c9adb

MediaSessionService: Nullify the media button sesison when it's removed

When the media button sesison is removed, we'd better not pick the
alternative media button session within the app because the alternative
media session might be a dummy which isn't able to handle media keys.

Test: Run the CtsMediaTest (MediaSessionTest and MediaSessionManagerTest)
  and the manual test (Launch a media app which creates two media
  sessions, and confirmed that another media session doesn't become the
  media button session when the media button session is removed)

Change-Id: I376a34ee4b5d2344007594134c40b135b2c5a1bf

services/core/java/com/android/server/media/MediaSessionStack.java

diff --git a/services/core/java/com/android/server/media/MediaSessionStack.java b/services/core/java/com/android/server/media/MediaSessionStack.java
index 2f82915..0e69bca 100644
--- a/services/core/java/com/android/server/media/MediaSessionStack.java
+++ b/services/core/java/com/android/server/media/MediaSessionStack.java
@@ -121,9 +121,12 @@
     public void removeSession(MediaSessionRecord record) {
         mSessions.remove(record);
         if (mMediaButtonSession == record) {
-            // When the media button session is gone, try to find the alternative media session
-            // in the media button session app.
-            onMediaSessionChangeInMediaButtonSessionApp();
+            // When the media button session is removed, nullify the media button session and do not
+            // search for the alternative media session within the app. It's because the alternative
+            // media session might be a dummy which isn't able to handle the media key events.
+            mOnMediaButtonSessionChangedListener.onMediaButtonSessionChanged(
+                    mMediaButtonSession, null);
+            mMediaButtonSession = null;
         }
         clearCache(record.getUserId());
     }
@@ -157,7 +160,13 @@
         // In that case, we pick the media session whose PlaybackState matches
         // the audio playback configuration.
         if (mMediaButtonSession != null && mMediaButtonSession.getUid() == record.getUid()) {
-            onMediaSessionChangeInMediaButtonSessionApp();
+            MediaSessionRecord newMediaButtonSession =
+                    findMediaButtonSession(mMediaButtonSession.getUid());
+            if (newMediaButtonSession != mMediaButtonSession) {
+                mOnMediaButtonSessionChangedListener.onMediaButtonSessionChanged(
+                        mMediaButtonSession, newMediaButtonSession);
+                mMediaButtonSession = newMediaButtonSession;
+            }
         }
     }
 
@@ -200,22 +209,6 @@
     }
 
     /**
-     * Handle the change in a media session in the media button session app.
-     * <p>If the app has multiple media sessions, change in a media sesion in the app may change
-     * the media button session.
-     * @see #findMediaButtonSession
-     */
-    private void onMediaSessionChangeInMediaButtonSessionApp() {
-        MediaSessionRecord newMediaButtonSession =
-                findMediaButtonSession(mMediaButtonSession.getUid());
-        if (newMediaButtonSession != mMediaButtonSession) {
-            mOnMediaButtonSessionChangedListener.onMediaButtonSessionChanged(mMediaButtonSession,
-                    newMediaButtonSession);
-            mMediaButtonSession = newMediaButtonSession;
-        }
-    }
-
-    /**
      * Find the media button session with the given {@param uid}.
      * If the app has multiple media sessions, the media session matches the audio playback state
      * becomes the media button session.