Keep MediaSessionCompat and MediaSessionConnector in a separate class

These objects need to live beyond the player for supporting
MediaBrowserServiceCompat and Android Auto, so they need to move outside
of the MediaSessionPlayerUi class.

app/src/main/java/org/schabi/newpipe/player/Player.java

@@ -275,7 +275,7 @@ public Player(@NonNull final PlayerService service) {
         // notification ui in the UIs list, since the notification depends on the media session in
         // PlayerUi#initPlayer(), and UIs.call() guarantees UI order is preserved.
         UIs = new PlayerUiList(
-                new MediaSessionPlayerUi(this),
+                new MediaSessionPlayerUi(this, service.getSessionConnector()),
                 new NotificationPlayerUi(this)
         );
     }

app/src/main/java/org/schabi/newpipe/player/PlayerService.java

@@ -28,10 +28,12 @@
 import android.os.IBinder;
 import android.util.Log;
 
+import com.google.android.exoplayer2.ext.mediasession.MediaSessionConnector;
+
+import org.schabi.newpipe.player.mediabrowser.MediaBrowserConnector;
 import org.schabi.newpipe.player.mediasession.MediaSessionPlayerUi;
 import org.schabi.newpipe.util.ThemeHelper;
 
-
 /**
  * One service for all players.
  */
@@ -41,8 +43,8 @@ public final class PlayerService extends Service {
 
     private Player player;
 
-    private final IBinder mBinder = new PlayerService.LocalBinder();
-
+    private final IBinder mBinder = new LocalBinder();
+    private MediaBrowserConnector mediaBrowserConnector;
 
     /*//////////////////////////////////////////////////////////////////////////
     // Service's LifeCycle
@@ -56,7 +58,14 @@ public void onCreate() {
         assureCorrectAppLanguage(this);
         ThemeHelper.setTheme(this);
 
-        player = new Player(this);
+        mediaBrowserConnector = new MediaBrowserConnector(this);
+    }
+
+    private void initializePlayer() {
+        if (player == null) {
+            assert mediaBrowserConnector != null;
+            player = new Player(this);
+        }
     }
 
     @Override
@@ -73,6 +82,7 @@ public int onStartCommand(final Intent intent, final int flags, final int startI
             return START_NOT_STICKY;
         }
 
+        initializePlayer();
         player.handleIntent(intent);
         player.UIs().get(MediaSessionPlayerUi.class)
                 .ifPresent(ui -> ui.handleMediaButtonIntent(intent));
@@ -110,6 +120,10 @@ public void onDestroy() {
             Log.d(TAG, "destroy() called");
         }
         cleanup();
+        if (mediaBrowserConnector != null) {
+            mediaBrowserConnector.release();
+            mediaBrowserConnector = null;
+        }
     }
 
     private void cleanup() {
@@ -134,6 +148,10 @@ public IBinder onBind(final Intent intent) {
         return mBinder;
     }
 
+    public MediaSessionConnector getSessionConnector() {
+        return mediaBrowserConnector.getSessionConnector();
+    }
+
     public class LocalBinder extends Binder {
 
         public PlayerService getService() {

app/src/main/java/org/schabi/newpipe/player/mediabrowser/MediaBrowserConnector.java

@@ -0,0 +1,32 @@
+package org.schabi.newpipe.player.mediabrowser;
+
+import android.support.v4.media.session.MediaSessionCompat;
+
+import androidx.annotation.NonNull;
+
+import com.google.android.exoplayer2.ext.mediasession.MediaSessionConnector;
+
+import org.schabi.newpipe.player.PlayerService;
+
+public class MediaBrowserConnector {
+    private static final String TAG = MediaBrowserConnector.class.getSimpleName();
+
+    private final PlayerService playerService;
+    private final @NonNull MediaSessionConnector sessionConnector;
+    private final @NonNull MediaSessionCompat mediaSession;
+
+    public MediaBrowserConnector(@NonNull final PlayerService playerService) {
+        this.playerService = playerService;
+        mediaSession = new MediaSessionCompat(playerService, TAG);
+        sessionConnector = new MediaSessionConnector(mediaSession);
+        sessionConnector.setMetadataDeduplicationEnabled(true);
+    }
+
+    public @NonNull MediaSessionConnector getSessionConnector() {
+        return sessionConnector;
+    }
+
+    public void release() {
+        mediaSession.release();
+    }
+}

app/src/main/java/org/schabi/newpipe/player/mediasession/MediaSessionPlayerUi.java

@@ -28,14 +28,17 @@ public class MediaSessionPlayerUi extends PlayerUi
         implements SharedPreferences.OnSharedPreferenceChangeListener {
     private static final String TAG = "MediaSessUi";
 
-    private MediaSessionCompat mediaSession;
-    private MediaSessionConnector sessionConnector;
+    private final @NonNull MediaSessionCompat mediaSession;
+    private final @NonNull MediaSessionConnector sessionConnector;
 
     private final String ignoreHardwareMediaButtonsKey;
     private boolean shouldIgnoreHardwareMediaButtons = false;
 
-    public MediaSessionPlayerUi(@NonNull final Player player) {
+    public MediaSessionPlayerUi(@NonNull final Player player,
+                                @NonNull final MediaSessionConnector sessionConnector) {
         super(player);
+        this.mediaSession = sessionConnector.mediaSession;
+        this.sessionConnector = sessionConnector;
         ignoreHardwareMediaButtonsKey =
                 context.getString(R.string.ignore_hardware_media_buttons_key);
     }
@@ -45,10 +48,8 @@ public void initPlayer() {
         super.initPlayer();
         destroyPlayer(); // release previously used resources
 
-        mediaSession = new MediaSessionCompat(context, TAG);
         mediaSession.setActive(true);
 
-        sessionConnector = new MediaSessionConnector(mediaSession);
         sessionConnector.setQueueNavigator(new PlayQueueNavigator(mediaSession, player));
         sessionConnector.setPlayer(getForwardingPlayer());
 
@@ -61,34 +62,27 @@ public void initPlayer() {
         updateShouldIgnoreHardwareMediaButtons(player.getPrefs());
         player.getPrefs().registerOnSharedPreferenceChangeListener(this);
 
-        sessionConnector.setMetadataDeduplicationEnabled(true);
         sessionConnector.setMediaMetadataProvider(exoPlayer -> buildMediaMetadata());
     }
 
     @Override
     public void destroyPlayer() {
         super.destroyPlayer();
         player.getPrefs().unregisterOnSharedPreferenceChangeListener(this);
-        if (sessionConnector != null) {
-            sessionConnector.setMediaButtonEventHandler(null);
-            sessionConnector.setPlayer(null);
-            sessionConnector.setQueueNavigator(null);
-            sessionConnector = null;
-        }
-        if (mediaSession != null) {
-            mediaSession.setActive(false);
-            mediaSession.release();
-            mediaSession = null;
-        }
+        sessionConnector.setMediaButtonEventHandler(null);
+        sessionConnector.setPlayer(null);
+        sessionConnector.setQueueNavigator(null);
+        sessionConnector.setMediaMetadataProvider(null);
+
+        mediaSession.setActive(false);
     }
 
     @Override
     public void onThumbnailLoaded(@Nullable final Bitmap bitmap) {
         super.onThumbnailLoaded(bitmap);
-        if (sessionConnector != null) {
-            // the thumbnail is now loaded: invalidate the metadata to trigger a metadata update
-            sessionConnector.invalidateMediaSessionMetadata();
-        }
+
+        // the thumbnail is now loaded: invalidate the metadata to trigger a metadata update
+        sessionConnector.invalidateMediaSessionMetadata();
     }
 
 
@@ -111,7 +105,7 @@ public void handleMediaButtonIntent(final Intent intent) {
     }
 
     public Optional<MediaSessionCompat.Token> getSessionToken() {
-        return Optional.ofNullable(mediaSession).map(MediaSessionCompat::getSessionToken);
+        return Optional.of(mediaSession.getSessionToken());
     }