PlayerHolder: use object class to implement singleton pattern

app/src/main/java/org/schabi/newpipe/MainActivity.java

@@ -849,7 +849,7 @@ public class MainActivity extends AppCompatActivity {
             return;
         }
 
-        if (PlayerHolder.Companion.getInstance().isPlayerOpen()) {
+        if (PlayerHolder.INSTANCE.isPlayerOpen()) {
             // if the player is already open, no need for a broadcast receiver
             openMiniPlayerIfMissing();
         } else {
@@ -859,7 +859,7 @@ public class MainActivity extends AppCompatActivity {
                 public void onReceive(final Context context, final Intent intent) {
                     if (Objects.equals(intent.getAction(),
                             VideoDetailFragment.ACTION_PLAYER_STARTED)
-                            && PlayerHolder.Companion.getInstance().isPlayerOpen()) {
+                            && PlayerHolder.INSTANCE.isPlayerOpen()) {
                         openMiniPlayerIfMissing();
                         // At this point the player is added 100%, we can unregister. Other actions
                         // are useless since the fragment will not be removed after that.
@@ -874,7 +874,7 @@ public class MainActivity extends AppCompatActivity {
 
             // If the PlayerHolder is not bound yet, but the service is running, try to bind to it.
             // Once the connection is established, the ACTION_PLAYER_STARTED will be sent.
-            PlayerHolder.Companion.getInstance().tryBindIfNeeded(this);
+            PlayerHolder.INSTANCE.tryBindIfNeeded(this);
         }
     }
 

app/src/main/java/org/schabi/newpipe/RouterActivity.java

@@ -701,7 +701,7 @@ public class RouterActivity extends AppCompatActivity {
         }
 
         // ...the player is not running or in normal Video-mode/type
-        final PlayerType playerType = PlayerHolder.Companion.getInstance().getType();
+        final PlayerType playerType = PlayerHolder.INSTANCE.getType();
         return playerType == null || playerType == PlayerType.MAIN;
     }
 

app/src/main/java/org/schabi/newpipe/fragments/detail/VideoDetailFragment.kt

@@ -100,7 +100,7 @@ import org.schabi.newpipe.player.PlayerType
 import org.schabi.newpipe.player.event.OnKeyDownListener
 import org.schabi.newpipe.player.event.PlayerServiceExtendedEventListener
 import org.schabi.newpipe.player.helper.PlayerHelper
-import org.schabi.newpipe.player.helper.PlayerHolder.Companion.getInstance
+import org.schabi.newpipe.player.helper.PlayerHolder
 import org.schabi.newpipe.player.playqueue.PlayQueue
 import org.schabi.newpipe.player.playqueue.SinglePlayQueue
 import org.schabi.newpipe.player.playqueue.events.PlayQueueEvent
@@ -212,7 +212,6 @@ class VideoDetailFragment :
     private var settingsContentObserver: ContentObserver? = null
     private var playerService: PlayerService? = null
     private var player: Player? = null
-    private val playerHolder = getInstance()
 
     /*//////////////////////////////////////////////////////////////////////////
     // Service management
@@ -367,9 +366,9 @@ class VideoDetailFragment :
         // Stop the service when user leaves the app with double back press
         // if video player is selected. Otherwise unbind
         if (activity.isFinishing() && this.isPlayerAvailable && player!!.videoPlayerSelected()) {
-            playerHolder.stopService()
+            PlayerHolder.stopService()
         } else {
-            playerHolder.setListener(null)
+            PlayerHolder.setListener(null)
         }
 
         PreferenceManager.getDefaultSharedPreferences(activity)
@@ -768,10 +767,10 @@ class VideoDetailFragment :
         )
 
         setupBottomPlayer()
-        if (!playerHolder.isBound) {
+        if (!PlayerHolder.isBound) {
             setHeightThumbnail()
         } else {
-            playerHolder.startService(false, this)
+            PlayerHolder.startService(false, this)
         }
     }
 
@@ -1175,7 +1174,7 @@ class VideoDetailFragment :
 
         // See UI changes while remote playQueue changes
         if (!this.isPlayerAvailable) {
-            playerHolder.startService(false, this)
+            PlayerHolder.startService(false, this)
         } else {
             // FIXME Workaround #7427
             player!!.setRecovery()
@@ -1245,7 +1244,7 @@ class VideoDetailFragment :
     private fun openNormalBackgroundPlayer(append: Boolean) {
         // See UI changes while remote playQueue changes
         if (!this.isPlayerAvailable) {
-            playerHolder.startService(false, this)
+            PlayerHolder.startService(false, this)
         }
 
         val queue = setupPlayQueueForIntent(append)
@@ -1263,7 +1262,7 @@ class VideoDetailFragment :
 
     private fun openMainPlayer() {
         if (noPlayerServiceAvailable()) {
-            playerHolder.startService(autoPlayEnabled, this)
+            PlayerHolder.startService(autoPlayEnabled, this)
             return
         }
         if (currentInfo == null) {
@@ -1298,7 +1297,7 @@ class VideoDetailFragment :
             playerService!!.stopForImmediateReusing()
             root.ifPresent(Consumer { view: View -> view.setVisibility(View.GONE) })
         } else {
-            playerHolder.stopService()
+            PlayerHolder.stopService()
         }
     }
 
@@ -1551,8 +1550,8 @@ class VideoDetailFragment :
                             bottomSheetBehavior!!.setState(BottomSheetBehavior.STATE_COLLAPSED)
                         }
                         // Rebound to the service if it was closed via notification or mini player
-                        if (!playerHolder.isBound) {
+                        if (!PlayerHolder.isBound) {
-                            playerHolder.startService(
+                            PlayerHolder.startService(
                                 false, this@VideoDetailFragment
                             )
                         }
@@ -2472,7 +2471,7 @@ class VideoDetailFragment :
         if (currentWorker != null) {
             currentWorker!!.dispose()
         }
-        playerHolder.stopService()
+        PlayerHolder.stopService()
         setInitialData(0, null, "", null)
         currentInfo = null
         updateOverlayData(null, null, mutableListOf<Image>())

app/src/main/java/org/schabi/newpipe/info_list/dialog/InfoItemDialog.java

@@ -252,7 +252,7 @@ public final class InfoItemDialog {
          * @return the current {@link Builder} instance
          */
         public Builder addEnqueueEntriesIfNeeded() {
-            final PlayerHolder holder = PlayerHolder.Companion.getInstance();
+            final PlayerHolder holder = PlayerHolder.INSTANCE;
             if (holder.isPlayQueueReady()) {
                 addEntry(StreamDialogDefaultEntry.ENQUEUE);
 

app/src/main/java/org/schabi/newpipe/player/helper/PlayerHolder.kt

@@ -22,12 +22,19 @@ import org.schabi.newpipe.player.playqueue.PlayQueue
 import org.schabi.newpipe.util.NavigationHelper
 import java.util.function.Consumer
 
-class PlayerHolder private constructor() {
+private val DEBUG = MainActivity.DEBUG
+private val TAG: String = PlayerHolder::class.java.getSimpleName()
+
+/**
+ * Singleton that manages a `PlayerService`
+ * and can be used to control the player instance through the service.
+ */
+object PlayerHolder {
     private var listener: PlayerServiceExtendedEventListener? = null
 
-    private val serviceConnection = PlayerServiceConnection()
     var isBound: Boolean = false
         private set
+
     private var playerService: PlayerService? = null
 
     private val player: Player?
@@ -110,7 +117,7 @@ class PlayerHolder private constructor() {
         val intent = Intent(context, PlayerService::class.java)
         intent.putExtra(PlayerService.SHOULD_START_FOREGROUND_EXTRA, true)
         ContextCompat.startForegroundService(context, intent)
-        serviceConnection.doPlayAfterConnect(playAfterConnect)
+        PlayerServiceConnection.doPlayAfterConnect(playAfterConnect)
         bind(context)
     }
 
@@ -126,7 +133,7 @@ class PlayerHolder private constructor() {
         context.stopService(Intent(context, PlayerService::class.java))
     }
 
-    internal inner class PlayerServiceConnection : ServiceConnection {
+    internal object PlayerServiceConnection : ServiceConnection {
         internal var playAfterConnect = false
 
         /**
@@ -185,7 +192,7 @@ class PlayerHolder private constructor() {
         // BIND_AUTO_CREATE starts the service if it's not already running
         this.isBound = bind(context, Context.BIND_AUTO_CREATE)
         if (!this.isBound) {
-            context.unbindService(serviceConnection)
+            context.unbindService(PlayerServiceConnection)
         }
     }
 
@@ -201,7 +208,7 @@ class PlayerHolder private constructor() {
     private fun bind(context: Context, flags: Int): Boolean {
         val serviceIntent = Intent(context, PlayerService::class.java)
         serviceIntent.setAction(PlayerService.BIND_PLAYER_HOLDER_ACTION)
-        return context.bindService(serviceIntent, serviceConnection, flags)
+        return context.bindService(serviceIntent, PlayerServiceConnection, flags)
     }
 
     private fun unbind(context: Context) {
@@ -210,7 +217,7 @@ class PlayerHolder private constructor() {
         }
 
         if (this.isBound) {
-            context.unbindService(serviceConnection)
+            context.unbindService(PlayerServiceConnection)
             this.isBound = false
             stopPlayerListener()
             playerService = null
@@ -223,18 +230,18 @@ class PlayerHolder private constructor() {
         // setting the player listener will take care of calling relevant callbacks if the
         // player in the service is (not) already active, also see playerStateListener below
         playerService?.setPlayerListener(playerStateListener)
-        this.player?.setFragmentListener(internalListener)
+        this.player?.setFragmentListener(HolderPlayerServiceEventListener)
     }
 
     private fun stopPlayerListener() {
         playerService?.setPlayerListener(null)
-        this.player?.removeFragmentListener(internalListener)
+        this.player?.removeFragmentListener(HolderPlayerServiceEventListener)
     }
 
     /**
      * This listener will be held by the players created by [PlayerService].
      */
-    private val internalListener: PlayerServiceEventListener = object : PlayerServiceEventListener {
+    private object HolderPlayerServiceEventListener : PlayerServiceEventListener {
         override fun onViewCreated() {
             listener?.onViewCreated()
         }
@@ -307,26 +314,11 @@ class PlayerHolder private constructor() {
                 // before setting its player to null
                 l.onPlayerDisconnected()
             } else {
-                l.onPlayerConnected(player, serviceConnection.playAfterConnect)
+                l.onPlayerConnected(player, PlayerServiceConnection.playAfterConnect)
                 // reset the value of playAfterConnect: if it was true before, it is now "consumed"
-                serviceConnection.playAfterConnect = false;
+                PlayerServiceConnection.playAfterConnect = false
-                player.setFragmentListener(internalListener)
+                player.setFragmentListener(HolderPlayerServiceEventListener)
             }
         }
     }
-
-    companion object {
-        private var instance: PlayerHolder? = null
-
-        @Synchronized
-        fun getInstance(): PlayerHolder {
-            if (instance == null) {
-                instance = PlayerHolder()
-            }
-            return instance!!
-        }
-
-        private val DEBUG = MainActivity.DEBUG
-        private val TAG: String = PlayerHolder::class.java.getSimpleName()
-    }
 }

app/src/main/java/org/schabi/newpipe/ui/components/items/stream/StreamMenu.kt

@@ -28,10 +28,9 @@ fun StreamMenu(
 ) {
     val context = LocalContext.current
     val streamViewModel = viewModel<StreamViewModel>()
-    val playerHolder = PlayerHolder.Companion.getInstance()
 
     DropdownMenu(expanded = expanded, onDismissRequest = onDismissRequest) {
-        if (playerHolder.isPlayQueueReady) {
+        if (PlayerHolder.isPlayQueueReady) {
             DropdownMenuItem(
                 text = { Text(text = stringResource(R.string.enqueue_stream)) },
                 onClick = {
@@ -42,7 +41,7 @@ fun StreamMenu(
                 }
             )
 
-            if (playerHolder.queuePosition < playerHolder.queueSize - 1) {
+            if (PlayerHolder.queuePosition < PlayerHolder.queueSize - 1) {
                 DropdownMenuItem(
                     text = { Text(text = stringResource(R.string.enqueue_next_stream)) },
                     onClick = {

app/src/main/java/org/schabi/newpipe/util/NavigationHelper.java

@@ -200,7 +200,7 @@ public final class NavigationHelper {
     }
 
     public static void enqueueOnPlayer(final Context context, final PlayQueue queue) {
-        PlayerType playerType = PlayerHolder.Companion.getInstance().getType();
+        PlayerType playerType = PlayerHolder.INSTANCE.getType();
         if (playerType == null) {
             Log.e(TAG, "Enqueueing but no player is open; defaulting to background player");
             playerType = PlayerType.AUDIO;
@@ -211,7 +211,7 @@ public final class NavigationHelper {
 
     /* ENQUEUE NEXT */
     public static void enqueueNextOnPlayer(final Context context, final PlayQueue queue) {
-        PlayerType playerType = PlayerHolder.Companion.getInstance().getType();
+        PlayerType playerType = PlayerHolder.INSTANCE.getType();
         if (playerType == null) {
             Log.e(TAG, "Enqueueing next but no player is open; defaulting to background player");
             playerType = PlayerType.AUDIO;
@@ -421,13 +421,13 @@ public final class NavigationHelper {
                                                final boolean switchingPlayers) {
 
         final boolean autoPlay;
-        @Nullable final PlayerType playerType = PlayerHolder.Companion.getInstance().getType();
+        @Nullable final PlayerType playerType = PlayerHolder.INSTANCE.getType();
         if (playerType == null) {
             // no player open
             autoPlay = PlayerHelper.isAutoplayAllowedByUser(context);
         } else if (switchingPlayers) {
             // switching player to main player
-            autoPlay = PlayerHolder.Companion.getInstance().isPlaying(); // keep play/pause state
+            autoPlay = PlayerHolder.INSTANCE.isPlaying(); // keep play/pause state
         } else if (playerType == PlayerType.MAIN) {
             // opening new stream while already playing in main player
             autoPlay = PlayerHelper.isAutoplayAllowedByUser(context);