Handle playback with PlaybackManager

app/src/main/java/code/name/monkey/retromusic/service/CrossFadePlayer.kt

@@ -14,7 +14,9 @@ import androidx.core.net.toUri
 import code.name.monkey.appthemehelper.util.VersionUtils.hasMarshmallow
 import code.name.monkey.retromusic.R
 import code.name.monkey.retromusic.extensions.showToast
+import code.name.monkey.retromusic.extensions.uri
 import code.name.monkey.retromusic.helper.MusicPlayerRemote
+import code.name.monkey.retromusic.model.Song
 import code.name.monkey.retromusic.service.AudioFader.Companion.createFadeAnimator
 import code.name.monkey.retromusic.service.playback.Playback
 import code.name.monkey.retromusic.service.playback.Playback.PlaybackCallbacks
@@ -124,18 +126,26 @@ class CrossFadePlayer(val context: Context) : Playback, MediaPlayer.OnCompletion
     override val isPlaying: Boolean
         get() = mIsInitialized && getCurrentPlayer()?.isPlaying == true
 
-    override fun setDataSource(path: String, force: Boolean): Boolean {
+    override fun setDataSource(
+        song: Song,
+        force: Boolean,
+        completion: (success: Boolean) -> Unit,
+    ) {
         cancelFade()
         if (force) hasDataSource = false
         mIsInitialized = false
         /* We've already set DataSource if initialized is true in setNextDataSource */
         if (!hasDataSource) {
-            getCurrentPlayer()?.let { mIsInitialized = setDataSourceImpl(it, path) }
+            getCurrentPlayer()?.let {
+                setDataSourceImpl(it, song.uri.toString()) { success ->
+                    mIsInitialized = success
+                    completion(success)
+                }
+            }
             hasDataSource = true
         } else {
             mIsInitialized = true
         }
-        return mIsInitialized
     }
 
     override fun setNextDataSource(path: String?) {}
@@ -148,9 +158,9 @@ class CrossFadePlayer(val context: Context) : Playback, MediaPlayer.OnCompletion
     private fun setDataSourceImpl(
         player: MediaPlayer,
         path: String,
-    ): Boolean {
+        completion: (success: Boolean) -> Unit,
+    ) {
         player.reset()
-        player.setOnPreparedListener(null)
         try {
             if (path.startsWith("content://")) {
                 player.setDataSource(context, path.toUri())
@@ -160,20 +170,18 @@ class CrossFadePlayer(val context: Context) : Playback, MediaPlayer.OnCompletion
             player.setAudioAttributes(
                 AudioAttributes.Builder().setLegacyStreamType(AudioManager.STREAM_MUSIC).build()
             )
-            player.prepare()
+            player.setPlaybackSpeedPitch(PreferenceUtil.playbackSpeed, PreferenceUtil.playbackPitch)
-            player.setPlaybackSpeedPitch(playbackSpeed, playbackPitch)
+            player.setOnPreparedListener {
+                player.setOnPreparedListener(null)
+                completion(true)
+            }
+            player.prepareAsync()
         } catch (e: Exception) {
+            completion(false)
             e.printStackTrace()
-            return false
         }
         player.setOnCompletionListener(this)
         player.setOnErrorListener(this)
-        val intent = Intent(AudioEffect.ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION)
-        intent.putExtra(AudioEffect.EXTRA_AUDIO_SESSION, audioSessionId)
-        intent.putExtra(AudioEffect.EXTRA_PACKAGE_NAME, context.packageName)
-        intent.putExtra(AudioEffect.EXTRA_CONTENT_TYPE, AudioEffect.CONTENT_TYPE_MUSIC)
-        context.sendBroadcast(intent)
-        return true
     }
 
     override fun setAudioSessionId(sessionId: Int): Boolean {
@@ -321,9 +329,11 @@ class CrossFadePlayer(val context: Context) : Playback, MediaPlayer.OnCompletion
             getNextPlayer()?.let { player ->
                 val nextSong = MusicPlayerRemote.nextSong
                 if (nextSong != null) {
-                    setDataSourceImpl(player, MusicUtil.getSongFileUri(nextSong.id).toString())
+                    setDataSourceImpl(player,
-                    // Switch to other player / Crossfade only if next song exists
+                        MusicUtil.getSongFileUri(nextSong.id).toString()) { success ->
-                    switchPlayer()
+                        // Switch to other player (Crossfade) only if next song exists
+                        if (success) switchPlayer()
+                    }
                 }
             }
         }

app/src/main/java/code/name/monkey/retromusic/service/MultiPlayer.java

@@ -1,368 +0,0 @@
-/*
- * Copyright (c) 2019 Hemanth Savarala.
- *
- * Licensed under the GNU General Public License v3
- *
- * This is free software: you can redistribute it and/or modify it under
- * the terms of the GNU General Public License as published by
- *  the Free Software Foundation either version 3 of the License, or (at your option) any later version.
- *
- * This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
- * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- * See the GNU General Public License for more details.
- */
-
-package code.name.monkey.retromusic.service;
-
-import android.content.Context;
-import android.content.Intent;
-import android.media.AudioManager;
-import android.media.MediaPlayer;
-import android.media.PlaybackParams;
-import android.media.audiofx.AudioEffect;
-import android.net.Uri;
-import android.os.PowerManager;
-import android.util.Log;
-import android.widget.Toast;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
-import org.jetbrains.annotations.NotNull;
-
-import code.name.monkey.appthemehelper.util.VersionUtils;
-import code.name.monkey.retromusic.R;
-import code.name.monkey.retromusic.service.playback.Playback;
-import code.name.monkey.retromusic.util.PreferenceUtil;
-
-/**
- * @author Andrew Neal, Karim Abou Zeid (kabouzeid)
- */
-public class MultiPlayer
-        implements Playback, MediaPlayer.OnErrorListener, MediaPlayer.OnCompletionListener {
-    public static final String TAG = MultiPlayer.class.getSimpleName();
-
-    private MediaPlayer mCurrentMediaPlayer = new MediaPlayer();
-    private MediaPlayer mNextMediaPlayer;
-
-    private final Context context;
-    @Nullable
-    private Playback.PlaybackCallbacks callbacks;
-
-    private boolean mIsInitialized = false;
-
-    /**
-     * Constructor of <code>MultiPlayer</code>
-     */
-    MultiPlayer(final Context context) {
-        this.context = context;
-        mCurrentMediaPlayer.setWakeMode(context, PowerManager.PARTIAL_WAKE_LOCK);
-    }
-
-    /**
-     * @param path The path of the file, or the http/rtsp URL of the stream you want to play
-     * @return True if the <code>player</code> has been prepared and is ready to play, false otherwise
-     */
-    @Override
-    public boolean setDataSource(@NotNull final String path, boolean force) {
-        mIsInitialized = false;
-        mIsInitialized = setDataSourceImpl(mCurrentMediaPlayer, path);
-        if (mIsInitialized) {
-            setNextDataSource(null);
-        }
-        return mIsInitialized;
-    }
-
-    /**
-     * @param player The {@link MediaPlayer} to use
-     * @param path   The path of the file, or the http/rtsp URL of the stream you want to play
-     * @return True if the <code>player</code> has been prepared and is ready to play, false otherwise
-     */
-    private boolean setDataSourceImpl(@NonNull final MediaPlayer player, @NonNull final String path) {
-        if (context == null) {
-            return false;
-        }
-        try {
-            player.reset();
-            player.setOnPreparedListener(null);
-            if (path.startsWith("content://")) {
-                player.setDataSource(context, Uri.parse(path));
-            } else {
-                player.setDataSource(path);
-            }
-            setPlaybackSpeedPitch(PreferenceUtil.INSTANCE.getPlaybackSpeed(), PreferenceUtil.INSTANCE.getPlaybackPitch());
-            player.setAudioStreamType(AudioManager.STREAM_MUSIC);
-            player.prepare();
-        } catch (Exception e) {
-            return false;
-        }
-        player.setOnCompletionListener(this);
-        player.setOnErrorListener(this);
-        final Intent intent = new Intent(AudioEffect.ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION);
-        intent.putExtra(AudioEffect.EXTRA_AUDIO_SESSION, getAudioSessionId());
-        intent.putExtra(AudioEffect.EXTRA_PACKAGE_NAME, context.getPackageName());
-        intent.putExtra(AudioEffect.EXTRA_CONTENT_TYPE, AudioEffect.CONTENT_TYPE_MUSIC);
-        context.sendBroadcast(intent);
-        return true;
-    }
-
-    /**
-     * Set the MediaPlayer to start when this MediaPlayer finishes playback.
-     *
-     * @param path The path of the file, or the http/rtsp URL of the stream you want to play
-     */
-    @Override
-    public void setNextDataSource(@Nullable final String path) {
-        if (context == null) {
-            return;
-        }
-        try {
-            mCurrentMediaPlayer.setNextMediaPlayer(null);
-        } catch (IllegalArgumentException e) {
-            Log.i(TAG, "Next media player is current one, continuing");
-        } catch (IllegalStateException e) {
-            Log.e(TAG, "Media player not initialized!");
-            return;
-        }
-        if (mNextMediaPlayer != null) {
-            mNextMediaPlayer.release();
-            mNextMediaPlayer = null;
-        }
-        if (path == null) {
-            return;
-        }
-        if (PreferenceUtil.INSTANCE.isGapLessPlayback()) {
-            mNextMediaPlayer = new MediaPlayer();
-            mNextMediaPlayer.setWakeMode(context, PowerManager.PARTIAL_WAKE_LOCK);
-            mNextMediaPlayer.setAudioSessionId(getAudioSessionId());
-            if (setDataSourceImpl(mNextMediaPlayer, path)) {
-                try {
-                    mCurrentMediaPlayer.setNextMediaPlayer(mNextMediaPlayer);
-                } catch (@NonNull IllegalArgumentException | IllegalStateException e) {
-                    Log.e(TAG, "setNextDataSource: setNextMediaPlayer()", e);
-                    if (mNextMediaPlayer != null) {
-                        mNextMediaPlayer.release();
-                        mNextMediaPlayer = null;
-                    }
-                }
-            } else {
-                if (mNextMediaPlayer != null) {
-                    mNextMediaPlayer.release();
-                    mNextMediaPlayer = null;
-                }
-            }
-        }
-    }
-
-    /**
-     * Sets the callbacks
-     *
-     * @param callbacks The callbacks to use
-     */
-    @Override
-    public void setCallbacks(@Nullable final Playback.PlaybackCallbacks callbacks) {
-        this.callbacks = callbacks;
-    }
-
-    /**
-     * @return True if the player is ready to go, false otherwise
-     */
-    @Override
-    public boolean isInitialized() {
-        return mIsInitialized;
-    }
-
-    /**
-     * Starts or resumes playback.
-     */
-    @Override
-    public boolean start() {
-        try {
-            mCurrentMediaPlayer.start();
-            return true;
-        } catch (IllegalStateException e) {
-            return false;
-        }
-    }
-
-    /**
-     * Resets the MediaPlayer to its uninitialized state.
-     */
-    @Override
-    public void stop() {
-        mCurrentMediaPlayer.reset();
-        mIsInitialized = false;
-    }
-
-    /**
-     * Releases resources associated with this MediaPlayer object.
-     */
-    @Override
-    public void release() {
-        stop();
-        mCurrentMediaPlayer.release();
-        if (mNextMediaPlayer != null) {
-            mNextMediaPlayer.release();
-        }
-    }
-
-    /**
-     * Pauses playback. Call start() to resume.
-     */
-    @Override
-    public boolean pause() {
-        try {
-            mCurrentMediaPlayer.pause();
-            return true;
-        } catch (IllegalStateException e) {
-            return false;
-        }
-    }
-
-    /**
-     * Checks whether the MultiPlayer is playing.
-     */
-    @Override
-    public boolean isPlaying() {
-        return mIsInitialized && mCurrentMediaPlayer.isPlaying();
-    }
-
-    /**
-     * Gets the duration of the file.
-     *
-     * @return The duration in milliseconds
-     */
-    @Override
-    public int duration() {
-        if (!mIsInitialized) {
-            return -1;
-        }
-        try {
-            return mCurrentMediaPlayer.getDuration();
-        } catch (IllegalStateException e) {
-            return -1;
-        }
-    }
-
-    /**
-     * Gets the current playback position.
-     *
-     * @return The current position in milliseconds
-     */
-    @Override
-    public int position() {
-        if (!mIsInitialized) {
-            return -1;
-        }
-        try {
-            return mCurrentMediaPlayer.getCurrentPosition();
-        } catch (IllegalStateException e) {
-            return -1;
-        }
-    }
-
-    /**
-     * Gets the current playback position.
-     *
-     * @param whereto The offset in milliseconds from the start to seek to
-     * @return The offset in milliseconds from the start to seek to
-     */
-    @Override
-    public int seek(final int whereto) {
-        try {
-            mCurrentMediaPlayer.seekTo(whereto);
-            return whereto;
-        } catch (IllegalStateException e) {
-            return -1;
-        }
-    }
-
-    @Override
-    public boolean setVolume(final float vol) {
-        try {
-            mCurrentMediaPlayer.setVolume(vol, vol);
-            return true;
-        } catch (IllegalStateException e) {
-            return false;
-        }
-    }
-
-    /**
-     * Sets the audio session ID.
-     *
-     * @param sessionId The audio session ID
-     */
-    @Override
-    public boolean setAudioSessionId(final int sessionId) {
-        try {
-            mCurrentMediaPlayer.setAudioSessionId(sessionId);
-            return true;
-        } catch (@NonNull IllegalArgumentException | IllegalStateException e) {
-            return false;
-        }
-    }
-
-    /**
-     * Returns the audio session ID.
-     *
-     * @return The current audio session ID.
-     */
-    @Override
-    public int getAudioSessionId() {
-        return mCurrentMediaPlayer.getAudioSessionId();
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    public boolean onError(final MediaPlayer mp, final int what, final int extra) {
-        mIsInitialized = false;
-        mCurrentMediaPlayer.release();
-        mCurrentMediaPlayer = new MediaPlayer();
-        mCurrentMediaPlayer.setWakeMode(context, PowerManager.PARTIAL_WAKE_LOCK);
-        if (context != null) {
-            Toast.makeText(
-                    context,
-                    context.getResources().getString(R.string.unplayable_file),
-                    Toast.LENGTH_SHORT)
-                    .show();
-            Log.e(TAG, String.valueOf(what) + extra);
-        }
-        return false;
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    public void onCompletion(final MediaPlayer mp) {
-        if (mp.equals(mCurrentMediaPlayer) && mNextMediaPlayer != null) {
-            mIsInitialized = false;
-            mCurrentMediaPlayer.release();
-            mCurrentMediaPlayer = mNextMediaPlayer;
-            mIsInitialized = true;
-            mNextMediaPlayer = null;
-            if (callbacks != null) callbacks.onTrackWentToNext();
-        } else {
-            if (callbacks != null) callbacks.onTrackEnded();
-        }
-    }
-
-    @Override
-    public void setCrossFadeDuration(int duration) {
-    }
-
-    @Override
-    public void setPlaybackSpeedPitch(float speed, float pitch) {
-        if (VersionUtils.INSTANCE.hasMarshmallow()) {
-            boolean wasPlaying = mCurrentMediaPlayer.isPlaying();
-            mCurrentMediaPlayer.setPlaybackParams(new PlaybackParams()
-                    .setSpeed(PreferenceUtil.INSTANCE.getPlaybackSpeed())
-                    .setPitch(PreferenceUtil.INSTANCE.getPlaybackPitch()));
-            if (!wasPlaying) {
-                if (mCurrentMediaPlayer.isPlaying()) mCurrentMediaPlayer.pause();
-            }
-        }
-    }
-}

app/src/main/java/code/name/monkey/retromusic/service/MultiPlayer.kt

@@ -0,0 +1,379 @@
+/*
+ * Copyright (c) 2019 Hemanth Savarala.
+ *
+ * Licensed under the GNU General Public License v3
+ *
+ * This is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by
+ *  the Free Software Foundation either version 3 of the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ */
+package code.name.monkey.retromusic.service
+
+import android.content.Context
+import android.content.Intent
+import android.content.SharedPreferences
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener
+import android.media.AudioAttributes
+import android.media.MediaPlayer
+import android.media.MediaPlayer.OnCompletionListener
+import android.media.PlaybackParams
+import android.media.audiofx.AudioEffect
+import android.net.Uri
+import android.os.PowerManager
+import android.util.Log
+import androidx.preference.PreferenceManager
+import code.name.monkey.appthemehelper.util.VersionUtils.hasMarshmallow
+import code.name.monkey.retromusic.PLAYBACK_PITCH
+import code.name.monkey.retromusic.PLAYBACK_SPEED
+import code.name.monkey.retromusic.R
+import code.name.monkey.retromusic.extensions.showToast
+import code.name.monkey.retromusic.extensions.uri
+import code.name.monkey.retromusic.model.Song
+import code.name.monkey.retromusic.service.playback.Playback
+import code.name.monkey.retromusic.service.playback.Playback.PlaybackCallbacks
+import code.name.monkey.retromusic.util.PreferenceUtil.isGapLessPlayback
+import code.name.monkey.retromusic.util.PreferenceUtil.playbackPitch
+import code.name.monkey.retromusic.util.PreferenceUtil.playbackSpeed
+
+/**
+ * @author Andrew Neal, Karim Abou Zeid (kabouzeid)
+ */
+class MultiPlayer internal constructor(private val context: Context) : Playback,
+    MediaPlayer.OnErrorListener, OnCompletionListener, OnSharedPreferenceChangeListener {
+    private var mCurrentMediaPlayer = MediaPlayer()
+    private var mNextMediaPlayer: MediaPlayer? = null
+    private var callbacks: PlaybackCallbacks? = null
+
+    /**
+     * @return True if the player is ready to go, false otherwise
+     */
+    override var isInitialized = false
+        private set
+
+    /**
+     * @param path The path of the file, or the http/rtsp URL of the stream you want to play
+     * @return True if the `player` has been prepared and is ready to play, false otherwise
+     */
+    override fun setDataSource(
+        song: Song,
+        force: Boolean,
+        completion: (success: Boolean) -> Unit,
+    ) {
+        isInitialized = false
+        setDataSourceImpl(mCurrentMediaPlayer, song.uri.toString()) { success ->
+            isInitialized = success
+            if (isInitialized) {
+                setNextDataSource(null)
+            }
+            completion(isInitialized)
+        }
+    }
+
+    /**
+     * @param player The [MediaPlayer] to use
+     * @param path   The path of the file, or the http/rtsp URL of the stream you want to play
+     * @return True if the `player` has been prepared and is ready to play, false otherwise
+     */
+    private fun setDataSourceImpl(
+        player: MediaPlayer,
+        path: String,
+        completion: (success: Boolean) -> Unit,
+    ) {
+        try {
+            player.reset()
+            player.setOnPreparedListener(null)
+            if (path.startsWith("content://")) {
+                player.setDataSource(context, Uri.parse(path))
+            } else {
+                player.setDataSource(path)
+            }
+            setPlaybackSpeedPitch(player)
+            player.setAudioAttributes(AudioAttributes.Builder()
+                .setUsage(AudioAttributes.USAGE_MEDIA)
+                .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
+                .build()
+            )
+            player.setOnPreparedListener {
+                player.setOnPreparedListener(null)
+                completion(true)
+            }
+            player.prepareAsync()
+        } catch (e: Exception) {
+            completion(false)
+            e.printStackTrace()
+        }
+        player.setOnCompletionListener(this)
+        player.setOnErrorListener(this)
+    }
+
+    fun openEqualizerSession() {
+        val intent = Intent(AudioEffect.ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION)
+        intent.putExtra(AudioEffect.EXTRA_AUDIO_SESSION, audioSessionId)
+        intent.putExtra(AudioEffect.EXTRA_PACKAGE_NAME, context.packageName)
+        intent.putExtra(AudioEffect.EXTRA_CONTENT_TYPE, AudioEffect.CONTENT_TYPE_MUSIC)
+        context.sendBroadcast(intent)
+    }
+
+    fun closeEqualizerSession() {
+        val intent = Intent(AudioEffect.ACTION_CLOSE_AUDIO_EFFECT_CONTROL_SESSION)
+        intent.putExtra(AudioEffect.EXTRA_AUDIO_SESSION, audioSessionId)
+        intent.putExtra(AudioEffect.EXTRA_PACKAGE_NAME, context.packageName)
+        intent.putExtra(AudioEffect.EXTRA_CONTENT_TYPE, AudioEffect.CONTENT_TYPE_MUSIC)
+        context.sendBroadcast(intent)
+    }
+
+    /**
+     * Set the MediaPlayer to start when this MediaPlayer finishes playback.
+     *
+     * @param path The path of the file, or the http/rtsp URL of the stream you want to play
+     */
+    override fun setNextDataSource(path: String?) {
+        try {
+            mCurrentMediaPlayer.setNextMediaPlayer(null)
+        } catch (e: IllegalArgumentException) {
+            Log.i(TAG, "Next media player is current one, continuing")
+        } catch (e: IllegalStateException) {
+            Log.e(TAG, "Media player not initialized!")
+            return
+        }
+        if (mNextMediaPlayer != null) {
+            mNextMediaPlayer?.release()
+            mNextMediaPlayer = null
+        }
+        if (path == null) {
+            return
+        }
+        if (isGapLessPlayback) {
+            mNextMediaPlayer = MediaPlayer()
+            mNextMediaPlayer?.setWakeMode(context, PowerManager.PARTIAL_WAKE_LOCK)
+            mNextMediaPlayer?.audioSessionId = audioSessionId
+            setDataSourceImpl(mNextMediaPlayer!!, path) { success ->
+                if (success) {
+                    try {
+                        mCurrentMediaPlayer.setNextMediaPlayer(mNextMediaPlayer)
+                    } catch (e: IllegalArgumentException) {
+                        Log.e(TAG, "setNextDataSource: setNextMediaPlayer()", e)
+                        if (mNextMediaPlayer != null) {
+                            mNextMediaPlayer?.release()
+                            mNextMediaPlayer = null
+                        }
+                    } catch (e: IllegalStateException) {
+                        Log.e(TAG, "setNextDataSource: setNextMediaPlayer()", e)
+                        if (mNextMediaPlayer != null) {
+                            mNextMediaPlayer?.release()
+                            mNextMediaPlayer = null
+                        }
+                    }
+                } else {
+                    if (mNextMediaPlayer != null) {
+                        mNextMediaPlayer?.release()
+                        mNextMediaPlayer = null
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Sets the callbacks
+     *
+     * @param callbacks The callbacks to use
+     */
+    override fun setCallbacks(callbacks: PlaybackCallbacks) {
+        this.callbacks = callbacks
+    }
+
+    /**
+     * Starts or resumes playback.
+     */
+    override fun start(): Boolean {
+        return try {
+            mCurrentMediaPlayer.start()
+            true
+        } catch (e: IllegalStateException) {
+            false
+        }
+    }
+
+    /**
+     * Resets the MediaPlayer to its uninitialized state.
+     */
+    override fun stop() {
+        mCurrentMediaPlayer.reset()
+        isInitialized = false
+    }
+
+    /**
+     * Releases resources associated with this MediaPlayer object.
+     */
+    override fun release() {
+        stop()
+        mCurrentMediaPlayer.release()
+        if (mNextMediaPlayer != null) {
+            mNextMediaPlayer?.release()
+        }
+        PreferenceManager.getDefaultSharedPreferences(context)
+            .unregisterOnSharedPreferenceChangeListener(this)
+    }
+
+    /**
+     * Pauses playback. Call start() to resume.
+     */
+    override fun pause(): Boolean {
+        return try {
+            mCurrentMediaPlayer.pause()
+            true
+        } catch (e: IllegalStateException) {
+            false
+        }
+    }
+
+    /**
+     * Checks whether the MultiPlayer is playing.
+     */
+    override val isPlaying: Boolean
+        get() = isInitialized && mCurrentMediaPlayer.isPlaying
+
+    /**
+     * Gets the duration of the file.
+     *
+     * @return The duration in milliseconds
+     */
+    override fun duration(): Int {
+        return if (!this.isInitialized) {
+            -1
+        } else try {
+            mCurrentMediaPlayer.duration
+        } catch (e: IllegalStateException) {
+            -1
+        }
+    }
+
+    /**
+     * Gets the current playback position.
+     *
+     * @return The current position in milliseconds
+     */
+    override fun position(): Int {
+        return if (!this.isInitialized) {
+            -1
+        } else try {
+            mCurrentMediaPlayer.currentPosition
+        } catch (e: IllegalStateException) {
+            -1
+        }
+    }
+
+    /**
+     * Gets the current playback position.
+     *
+     * @param whereto The offset in milliseconds from the start to seek to
+     * @return The offset in milliseconds from the start to seek to
+     */
+    override fun seek(whereto: Int): Int {
+        return try {
+            mCurrentMediaPlayer.seekTo(whereto)
+            whereto
+        } catch (e: IllegalStateException) {
+            -1
+        }
+    }
+
+    override fun setVolume(vol: Float): Boolean {
+        return try {
+            mCurrentMediaPlayer.setVolume(vol, vol)
+            true
+        } catch (e: IllegalStateException) {
+            false
+        }
+    }
+
+    /**
+     * Sets the audio session ID.
+     *
+     * @param sessionId The audio session ID
+     */
+    override fun setAudioSessionId(sessionId: Int): Boolean {
+        return try {
+            mCurrentMediaPlayer.audioSessionId = sessionId
+            true
+        } catch (e: IllegalArgumentException) {
+            false
+        } catch (e: IllegalStateException) {
+            false
+        }
+    }
+
+    /**
+     * Returns the audio session ID.
+     *
+     * @return The current audio session ID.
+     */
+    override val audioSessionId: Int
+        get() = mCurrentMediaPlayer.audioSessionId
+
+    /**
+     * {@inheritDoc}
+     */
+    override fun onError(mp: MediaPlayer, what: Int, extra: Int): Boolean {
+        isInitialized = false
+        mCurrentMediaPlayer.release()
+        mCurrentMediaPlayer = MediaPlayer()
+        mCurrentMediaPlayer.setWakeMode(context, PowerManager.PARTIAL_WAKE_LOCK)
+        context.showToast(R.string.unplayable_file)
+        Log.e(TAG, what.toString() + extra)
+        return false
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    override fun onCompletion(mp: MediaPlayer) {
+        if (mp == mCurrentMediaPlayer && mNextMediaPlayer != null) {
+            isInitialized = false
+            mCurrentMediaPlayer.release()
+            mCurrentMediaPlayer = mNextMediaPlayer!!
+            isInitialized = true
+            mNextMediaPlayer = null
+            if (callbacks != null) callbacks?.onTrackWentToNext()
+        } else {
+            if (callbacks != null) callbacks?.onTrackEnded()
+        }
+    }
+
+    override fun setCrossFadeDuration(duration: Int) {}
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+        if (key == PLAYBACK_SPEED || key == PLAYBACK_PITCH) {
+            setPlaybackSpeedPitch(mCurrentMediaPlayer)
+        }
+    }
+
+    private fun setPlaybackSpeedPitch(mp: MediaPlayer) {
+        if (hasMarshmallow()) {
+            val wasPlaying = mp.isPlaying
+            mp.playbackParams = PlaybackParams()
+                .setSpeed(playbackSpeed)
+                .setPitch(playbackPitch)
+            if (!wasPlaying) {
+                if (mp.isPlaying) mp.pause()
+            }
+        }
+    }
+
+    companion object {
+        val TAG: String = MultiPlayer::class.java.simpleName
+    }
+
+    /**
+     * Constructor of `MultiPlayer`
+     */
+    init {
+        mCurrentMediaPlayer.setWakeMode(context, PowerManager.PARTIAL_WAKE_LOCK)
+        PreferenceManager.getDefaultSharedPreferences(context)
+            .registerOnSharedPreferenceChangeListener(this)
+    }
+}

app/src/main/java/code/name/monkey/retromusic/service/MusicService.kt

@@ -25,7 +25,6 @@ import android.graphics.Bitmap
 import android.graphics.drawable.Drawable
 import android.media.AudioManager
 import android.media.AudioManager.OnAudioFocusChangeListener
-import android.media.audiofx.AudioEffect
 import android.os.*
 import android.os.Build.VERSION
 import android.os.Build.VERSION_CODES
@@ -57,11 +56,11 @@ import code.name.monkey.retromusic.auto.AutoMediaIDHelper
 import code.name.monkey.retromusic.auto.AutoMusicProvider
 import code.name.monkey.retromusic.extensions.showToast
 import code.name.monkey.retromusic.extensions.toMediaSessionQueue
+import code.name.monkey.retromusic.extensions.uri
 import code.name.monkey.retromusic.glide.BlurTransformation
 import code.name.monkey.retromusic.glide.GlideApp
 import code.name.monkey.retromusic.glide.RetroGlideExtension.getDefaultTransition
 import code.name.monkey.retromusic.glide.RetroGlideExtension.getSongModel
-import code.name.monkey.retromusic.helper.MusicPlayerRemote.isCasting
 import code.name.monkey.retromusic.helper.ShuffleHelper.makeShuffleList
 import code.name.monkey.retromusic.model.Song
 import code.name.monkey.retromusic.model.Song.Companion.emptySong
@@ -69,14 +68,12 @@ import code.name.monkey.retromusic.model.smartplaylist.AbsSmartPlaylist
 import code.name.monkey.retromusic.providers.HistoryStore
 import code.name.monkey.retromusic.providers.MusicPlaybackQueueStore
 import code.name.monkey.retromusic.providers.SongPlayCountStore
-import code.name.monkey.retromusic.service.AudioFader.Companion.startFadeAnimator
 import code.name.monkey.retromusic.service.notification.PlayingNotification
 import code.name.monkey.retromusic.service.notification.PlayingNotificationClassic
 import code.name.monkey.retromusic.service.notification.PlayingNotificationImpl24
 import code.name.monkey.retromusic.service.playback.Playback
 import code.name.monkey.retromusic.service.playback.Playback.PlaybackCallbacks
 import code.name.monkey.retromusic.util.MusicUtil.getMediaStoreAlbumCoverUri
-import code.name.monkey.retromusic.util.MusicUtil.getSongFileUri
 import code.name.monkey.retromusic.util.MusicUtil.toggleFavorite
 import code.name.monkey.retromusic.util.PackageValidator
 import code.name.monkey.retromusic.util.PreferenceUtil.crossFadeDuration
@@ -96,6 +93,7 @@ import code.name.monkey.retromusic.volume.OnAudioVolumeChangedListener
 import com.bumptech.glide.request.target.CustomTarget
 import com.bumptech.glide.request.target.Target
 import com.bumptech.glide.request.transition.Transition
+import com.google.android.gms.cast.framework.CastSession
 import org.koin.java.KoinJavaComponent.get
 import java.util.*
 
@@ -112,8 +110,10 @@ class MusicService : MediaBrowserServiceCompat(),
     @JvmField
     var pendingQuit = false
 
-    @JvmField
+    private lateinit var playbackManager: PlaybackManager
-    var playback: Playback? = null
+
+    val playback: Playback? get() = playbackManager.playback
+
     private var mPackageValidator: PackageValidator? = null
     private val mMusicProvider = get<AutoMusicProvider>(AutoMusicProvider::class.java)
     private var trackEndedByCrossfade = false
@@ -288,15 +288,10 @@ class MusicService : MediaBrowserServiceCompat(),
         wakeLock?.setReferenceCounted(false)
         musicPlayerHandlerThread = HandlerThread("PlaybackHandler")
         musicPlayerHandlerThread?.start()
-        playerHandler = PlaybackHandler(this, musicPlayerHandlerThread!!.looper)
+        playerHandler = PlaybackHandler(this, mainLooper)
 
-        // Set MultiPlayer when crossfade duration is 0 i.e. off
+        playbackManager = PlaybackManager(this)
-        playback = if (crossFadeDuration == 0) {
+        playbackManager.setCallbacks(this)
-            MultiPlayer(this)
-        } else {
-            CrossFadePlayer(this)
-        }
-        playback?.setCallbacks(this)
         setupMediaSession()
 
         // queue saving needs to run on a separate thread so that it doesn't block the playback handler
@@ -457,11 +452,11 @@ class MusicService : MediaBrowserServiceCompat(),
     }
 
     val audioSessionId: Int
-        get() = if (playback != null) {
+        get() = playbackManager.audioSessionId
-            playback!!.audioSessionId
+
-        } else -1
     val currentSong: Song
         get() = getSongAt(getPosition())
+
     val nextSong: Song?
         get() = if (isLastTrack && repeatMode == REPEAT_MODE_NONE) {
             null
@@ -501,9 +496,11 @@ class MusicService : MediaBrowserServiceCompat(),
     }
 
     private fun setPosition(position: Int) {
-        // handle this on the handlers thread to avoid blocking the ui thread
+        openTrackAndPrepareNextAt(position) { success ->
-        playerHandler?.removeMessages(SET_POSITION)
+            if (success) {
-        playerHandler?.obtainMessage(SET_POSITION, position, 0)?.sendToTarget()
+                notifyChange(PLAY_STATE_CHANGED)
+            }
+        }
     }
 
     private fun getPreviousPosition(force: Boolean): Int {
@@ -577,13 +574,10 @@ class MusicService : MediaBrowserServiceCompat(),
     }
 
     val songDurationMillis: Int
-        get() = if (playback != null) {
+        get() = playbackManager.songDurationMillis
-            playback!!.duration()
+
-        } else -1
     val songProgressMillis: Int
-        get() = if (playback != null) {
+        get() = playbackManager.songProgressMillis
-            playback!!.position()
-        } else -1
 
     fun handleAndSendChangeInternal(what: String) {
         handleChangeInternal(what)
@@ -602,8 +596,9 @@ class MusicService : MediaBrowserServiceCompat(),
 
     val isLastTrack: Boolean
         get() = getPosition() == playingQueue.size - 1
+
     val isPlaying: Boolean
-        get() = playback != null && playback!!.isPlaying
+        get() = playbackManager.isPlaying
 
     fun moveSong(from: Int, to: Int) {
         if (from == to) {
@@ -702,38 +697,10 @@ class MusicService : MediaBrowserServiceCompat(),
             CROSS_FADE_DURATION -> {
                 val progress = songProgressMillis
                 val wasPlaying = isPlaying
-                /* Switch to MultiPlayer if Crossfade duration is 0 and
+
-                Playback is not an instance of MultiPlayer */
+                playbackManager.maybeSwitchToCrossFade(crossFadeDuration)
-                if (playback !is MultiPlayer && crossFadeDuration == 0) {
+                restorePlaybackState(wasPlaying, progress)
-                    if (playback != null) {
+
-                        playback?.release()
-                    }
-                    playback = null
-                    playback = MultiPlayer(this)
-                    playback?.setCallbacks(this)
-                    if (openTrackAndPrepareNextAt(position)) {
-                        seek(progress)
-                        if (wasPlaying) {
-                            play()
-                        }
-                    }
-                } else if (playback !is CrossFadePlayer && crossFadeDuration > 0) {
-                    if (playback != null) {
-                        playback?.release()
-                    }
-                    playback = null
-                    playback = CrossFadePlayer(this)
-                    playback?.setCallbacks(this)
-                    if (openTrackAndPrepareNextAt(position)) {
-                        seek(progress)
-                        if (wasPlaying) {
-                            play()
-                        }
-                    }
-                }
-                if (playback != null) playback?.setCrossFadeDuration(
-                    crossFadeDuration
-                )
             }
             ALBUM_ART_ON_LOCK_SCREEN, BLURRED_ALBUM_ART -> updateMediaSessionMetaData()
             COLORED_NOTIFICATION -> {
@@ -795,6 +762,10 @@ class MusicService : MediaBrowserServiceCompat(),
         playerHandler?.sendEmptyMessage(TRACK_WENT_TO_NEXT)
     }
 
+    override fun onPlayStateChanged() {
+        notifyChange(PLAY_STATE_CHANGED)
+    }
+
     override fun onUnbind(intent: Intent): Boolean {
         if (!isPlaying) {
             stopSelf()
@@ -828,34 +799,21 @@ class MusicService : MediaBrowserServiceCompat(),
     }
 
     @Synchronized
-    fun openTrackAndPrepareNextAt(position: Int): Boolean {
+    fun openTrackAndPrepareNextAt(position: Int, completion: (success: Boolean) -> Unit) {
         this.position = position
-        val prepared = openCurrent()
+        openCurrent { success ->
-        if (prepared) {
+            if (success) {
                 prepareNextImpl()
             }
             notifyChange(META_CHANGED)
             notHandledMetaChangedForCurrentTrack = false
-        return prepared
+            completion(success)
+        }
     }
 
-    fun pause() {
+    fun pause(force: Boolean = false) {
-        Log.i(TAG, "Paused")
         isPausedByTransientLossOfFocus = false
-        if (playback != null && playback!!.isPlaying) {
+        playbackManager.pause(force) {
-            startFadeAnimator(playback!!, false) {
-
-                //Code to run when Animator Ends
-                playback?.pause()
-                notifyChange(PLAY_STATE_CHANGED)
-            }
-        }
-    }
-
-    fun forcePause() {
-        isPausedByTransientLossOfFocus = false
-        if (playback != null && playback!!.isPlaying) {
-            playback?.pause()
             notifyChange(PLAY_STATE_CHANGED)
         }
     }
@@ -863,17 +821,8 @@ class MusicService : MediaBrowserServiceCompat(),
     @Synchronized
     fun play() {
         if (requestFocus()) {
-            if (playback != null && !playback!!.isPlaying) {
+            playbackManager.play(onNotInitialized = { playSongAt(getPosition()) }) {
-                if (!playback!!.isInitialized) {
-                    playSongAt(getPosition())
-                } else {
-                    //Don't Start playing when it's casting
-                    if (isCasting) {
-                        return
-                    }
-                    startFadeAnimator(playback!!, true) {
 
-                        // Code when Animator Ends
                 if (!becomingNoisyReceiverRegistered) {
                     registerReceiver(
                         becomingNoisyReceiver,
@@ -891,11 +840,7 @@ class MusicService : MediaBrowserServiceCompat(),
                 playerHandler?.removeMessages(DUCK)
                 playerHandler?.sendEmptyMessage(UNDUCK)
             }
-                    //Start Playback with Animator
-                    playback?.start()
             notifyChange(PLAY_STATE_CHANGED)
-                }
-            }
         } else {
             showToast(R.string.audio_focus_denied)
         }
@@ -910,18 +855,14 @@ class MusicService : MediaBrowserServiceCompat(),
     }
 
     fun playSongAt(position: Int) {
-        // handle this on the handlers thread to avoid blocking the ui thread
+        openTrackAndPrepareNextAt(position) { success ->
-        playerHandler?.removeMessages(PLAY_SONG)
+            if (success) {
-        playerHandler?.obtainMessage(PLAY_SONG, position, 0)?.sendToTarget()
-    }
-
-    fun playSongAtImpl(position: Int) {
-        if (openTrackAndPrepareNextAt(position)) {
                 play()
             } else {
                 showToast(resources.getString(R.string.unplayable_file))
             }
         }
+    }
 
     fun playSongs(songs: ArrayList<Song>?, shuffleMode: Int) {
         if (songs != null && songs.isNotEmpty()) {
@@ -942,7 +883,7 @@ class MusicService : MediaBrowserServiceCompat(),
     fun prepareNextImpl() {
         try {
             val nextPosition = getNextPosition(false)
-            playback?.setNextDataSource(getTrackUri(getSongAt(nextPosition)))
+            playbackManager.setNextDataSource(getSongAt(nextPosition).uri.toString())
             this.nextPosition = nextPosition
         } catch (ignored: Exception) {
         }
@@ -952,7 +893,7 @@ class MusicService : MediaBrowserServiceCompat(),
         pause()
         stopForeground(true)
         notificationManager?.cancel(PlayingNotification.NOTIFICATION_ID)
-        closeAudioEffectSession()
+        playbackManager.closeAudioEffectSession()
         audioManager?.abandonAudioFocus(audioFocusListener)
         stopSelf()
     }
@@ -1030,13 +971,15 @@ class MusicService : MediaBrowserServiceCompat(),
                 originalPlayingQueue = ArrayList(restoredOriginalQueue)
                 playingQueue = ArrayList(restoredQueue)
                 position = restoredPosition
-                openCurrent()
+                openCurrent {
                     prepareNext()
                     if (restoredPositionInTrack > 0) {
                         seek(restoredPositionInTrack)
                     }
                     notHandledMetaChangedForCurrentTrack = true
                     sendChangeInternal(META_CHANGED)
+                }
+
                 sendChangeInternal(QUEUE_CHANGED)
             }
         }
@@ -1067,9 +1010,7 @@ class MusicService : MediaBrowserServiceCompat(),
     fun seek(millis: Int): Int {
         return try {
             var newPosition = 0
-            if (playback != null) {
+            newPosition = playbackManager.seek(millis)
-                newPosition = playback!!.seek(millis)
-            }
             throttledSeekHandler?.notifySeek()
             newPosition
         } catch (e: Exception) {
@@ -1178,15 +1119,6 @@ class MusicService : MediaBrowserServiceCompat(),
         }
     }
 
-    private fun closeAudioEffectSession() {
-        val audioEffectsIntent = Intent(AudioEffect.ACTION_CLOSE_AUDIO_EFFECT_CONTROL_SESSION)
-        if (playback != null) {
-            audioEffectsIntent.putExtra(AudioEffect.EXTRA_AUDIO_SESSION, playback!!.audioSessionId)
-        }
-        audioEffectsIntent.putExtra(AudioEffect.EXTRA_PACKAGE_NAME, packageName)
-        sendBroadcast(audioEffectsIntent)
-    }
-
     private fun handleChangeInternal(what: String) {
         when (what) {
             PLAY_STATE_CHANGED -> {
@@ -1284,23 +1216,39 @@ class MusicService : MediaBrowserServiceCompat(),
     }
 
     @Synchronized
-    private fun openCurrent(): Boolean {
+    private fun openCurrent(completion: (success: Boolean) -> Unit) {
         val force = if (!trackEndedByCrossfade) {
             true
         } else {
             trackEndedByCrossfade = false
             false
         }
-        return try {
+        playbackManager.setDataSource(currentSong, force) { success ->
-            if (playback != null) {
+            completion(success)
-                return playback!!.setDataSource(getTrackUri(currentSong), force)
-            } else false
-        } catch (e: Exception) {
-            e.printStackTrace()
-            false
         }
     }
 
+    fun switchToLocalPlayback() {
+        playbackManager.switchToLocalPlayback(this::restorePlaybackState)
+    }
+
+    fun switchToRemotePlayback(castSession: CastSession) {
+        playbackManager.switchToRemotePlayback(castSession, this::restorePlaybackState)
+    }
+
+    private fun restorePlaybackState(wasPlaying: Boolean, progress: Int) {
+        playbackManager.setCallbacks(this)
+        openTrackAndPrepareNextAt(position) { success ->
+            if (success) {
+                seek(progress)
+                if (wasPlaying) {
+                    play()
+                }
+            }
+        }
+        playbackManager.setCrossFadeDuration(crossFadeDuration)
+    }
+
     private fun playFromPlaylist(intent: Intent) {
         val playlist: AbsSmartPlaylist? = intent.getParcelableExtra(INTENT_EXTRA_PLAYLIST)
         val shuffleMode = intent.getIntExtra(INTENT_EXTRA_SHUFFLE_MODE, getShuffleMode())
@@ -1347,10 +1295,7 @@ class MusicService : MediaBrowserServiceCompat(),
         musicPlayerHandlerThread?.quitSafely()
         queueSaveHandler?.removeCallbacksAndMessages(null)
         queueSaveHandlerThread?.quitSafely()
-        if (playback != null) {
+        playbackManager.release()
-            playback?.release()
-        }
-        playback = null
         mediaSession?.release()
     }
 
@@ -1508,9 +1453,5 @@ class MusicService : MediaBrowserServiceCompat(),
                 null
             }
         }
-
-        private fun getTrackUri(song: Song): String {
-            return getSongFileUri(song.id).toString()
-        }
     }
 }

app/src/main/java/code/name/monkey/retromusic/service/PlaybackHandler.kt

@@ -11,165 +11,116 @@
  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  * See the GNU General Public License for more details.
  */
+package code.name.monkey.retromusic.service
 
-package code.name.monkey.retromusic.service;
+import android.media.AudioManager
+import android.os.Handler
+import android.os.Looper
+import android.os.Message
+import code.name.monkey.retromusic.util.PreferenceUtil.isAudioDucking
+import code.name.monkey.retromusic.util.PreferenceUtil.isAudioFocusEnabled
+import java.lang.ref.WeakReference
 
-import static code.name.monkey.retromusic.service.MusicService.DUCK;
+internal class PlaybackHandler(service: MusicService, looper: Looper) : Handler(looper) {
-import static code.name.monkey.retromusic.service.MusicService.META_CHANGED;
+    private val mService: WeakReference<MusicService>
-import static code.name.monkey.retromusic.service.MusicService.PLAY_STATE_CHANGED;
+    private var currentDuckVolume = 1.0f
-import static code.name.monkey.retromusic.service.MusicService.REPEAT_MODE_NONE;
-import static code.name.monkey.retromusic.service.MusicService.TRACK_ENDED;
-import static code.name.monkey.retromusic.service.MusicService.TRACK_WENT_TO_NEXT;
 
-import android.media.AudioManager;
+    override fun handleMessage(msg: Message) {
-import android.os.Handler;
+        val service = mService.get() ?: return
-import android.os.Looper;
+        when (msg.what) {
-import android.os.Message;
+            MusicService.DUCK -> {
-
+                if (isAudioDucking) {
-import androidx.annotation.NonNull;
+                    currentDuckVolume -= .05f
-
-import java.lang.ref.WeakReference;
-
-import code.name.monkey.retromusic.util.PreferenceUtil;
-
-class PlaybackHandler extends Handler {
-
-  @NonNull private final WeakReference<MusicService> mService;
-  private float currentDuckVolume = 1.0f;
-
-
-  PlaybackHandler(final MusicService service, @NonNull final Looper looper) {
-    super(looper);
-    mService = new WeakReference<>(service);
-  }
-
-  @Override
-  public void handleMessage(@NonNull final Message msg) {
-    final MusicService service = mService.get();
-    if (service == null) {
-      return;
-    }
-
-    switch (msg.what) {
-      case MusicService.DUCK:
-        if (PreferenceUtil.INSTANCE.isAudioDucking()) {
-          currentDuckVolume -= .05f;
                     if (currentDuckVolume > .2f) {
-            sendEmptyMessageDelayed(DUCK, 10);
+                        sendEmptyMessageDelayed(MusicService.DUCK, 10)
                     } else {
-            currentDuckVolume = .2f;
+                        currentDuckVolume = .2f
                     }
                 } else {
-          currentDuckVolume = 1f;
+                    currentDuckVolume = 1f
                 }
-        service.playback.setVolume(currentDuckVolume);
+                service.playback?.setVolume(currentDuckVolume)
-        break;
+            }
-
+            MusicService.UNDUCK -> {
-      case MusicService.UNDUCK:
+                if (isAudioDucking) {
-        if (PreferenceUtil.INSTANCE.isAudioDucking()) {
+                    currentDuckVolume += .03f
-          currentDuckVolume += .03f;
                     if (currentDuckVolume < 1f) {
-            sendEmptyMessageDelayed(MusicService.UNDUCK, 10);
+                        sendEmptyMessageDelayed(MusicService.UNDUCK, 10)
                     } else {
-            currentDuckVolume = 1f;
+                        currentDuckVolume = 1f
                     }
                 } else {
-          currentDuckVolume = 1f;
+                    currentDuckVolume = 1f
                 }
-        service.playback.setVolume(currentDuckVolume);
+                service.playback?.setVolume(currentDuckVolume)
-        break;
+            }
-
+            MusicService.TRACK_WENT_TO_NEXT ->
-      case TRACK_WENT_TO_NEXT:
+                if (service.pendingQuit || service.repeatMode == MusicService.REPEAT_MODE_NONE && service.isLastTrack) {
-        if (service.pendingQuit
+                    service.pause(false)
-                || service.getRepeatMode() == REPEAT_MODE_NONE && service.isLastTrack()) {
+                    service.seek(0)
-          service.pause();
-          service.seek(0);
                     if (service.pendingQuit) {
-            service.pendingQuit = false;
+                        service.pendingQuit = false
-            service.quit();
+                        service.quit()
-            break;
                     }
                 } else {
-          service.position = service.nextPosition;
+                    service.position = service.nextPosition
-          service.prepareNextImpl();
+                    service.prepareNextImpl()
-          service.notifyChange(META_CHANGED);
+                    service.notifyChange(MusicService.META_CHANGED)
                 }
-        break;
+            MusicService.TRACK_ENDED -> {
-
-      case TRACK_ENDED:
                 // if there is a timer finished, don't continue
                 if (service.pendingQuit
-                || service.getRepeatMode() == REPEAT_MODE_NONE && service.isLastTrack()) {
+                    || service.repeatMode == MusicService.REPEAT_MODE_NONE && service.isLastTrack
-          service.notifyChange(PLAY_STATE_CHANGED);
+                ) {
-          service.seek(0);
+                    service.notifyChange(MusicService.PLAY_STATE_CHANGED)
+                    service.seek(0)
                     if (service.pendingQuit) {
-            service.pendingQuit = false;
+                        service.pendingQuit = false
-            service.quit();
+                        service.quit()
-            break;
                     }
                 } else {
-          service.playNextSong(false);
+                    service.playNextSong(false)
                 }
-        sendEmptyMessage(MusicService.RELEASE_WAKELOCK);
+                sendEmptyMessage(MusicService.RELEASE_WAKELOCK)
-        break;
-
-      case MusicService.RELEASE_WAKELOCK:
-        service.releaseWakeLock();
-        break;
-
-      case MusicService.PLAY_SONG:
-        service.playSongAtImpl(msg.arg1);
-        break;
-
-      case MusicService.SET_POSITION:
-        service.openTrackAndPrepareNextAt(msg.arg1);
-        service.notifyChange(PLAY_STATE_CHANGED);
-        break;
-
-      case MusicService.PREPARE_NEXT:
-        service.prepareNextImpl();
-        break;
-
-      case MusicService.RESTORE_QUEUES:
-        service.restoreQueuesAndPositionIfNecessary();
-        break;
-
-      case MusicService.FOCUS_CHANGE:
-        switch (msg.arg1) {
-          case AudioManager.AUDIOFOCUS_GAIN:
-            if (!service.isPlaying() && service.isPausedByTransientLossOfFocus()) {
-              service.play();
-              service.setPausedByTransientLossOfFocus(false);
             }
-            removeMessages(DUCK);
+            MusicService.RELEASE_WAKELOCK -> service.releaseWakeLock()
-            sendEmptyMessage(MusicService.UNDUCK);
+            MusicService.PREPARE_NEXT -> service.prepareNextImpl()
-            break;
+            MusicService.RESTORE_QUEUES -> service.restoreQueuesAndPositionIfNecessary()
-
+            MusicService.FOCUS_CHANGE -> when (msg.arg1) {
-          case AudioManager.AUDIOFOCUS_LOSS:
+                AudioManager.AUDIOFOCUS_GAIN -> {
+                    if (!service.isPlaying && service.isPausedByTransientLossOfFocus) {
+                        service.play()
+                        service.isPausedByTransientLossOfFocus = false
+                    }
+                    removeMessages(MusicService.DUCK)
+                    sendEmptyMessage(MusicService.UNDUCK)
+                }
+                AudioManager.AUDIOFOCUS_LOSS -> {
                     // Lost focus for an unbounded amount of time: stop playback and release media playback
-            boolean isAudioFocusEnabled = PreferenceUtil.INSTANCE.isAudioFocusEnabled();
+                    val isAudioFocusEnabled = isAudioFocusEnabled
                     if (!isAudioFocusEnabled) {
-              service.forcePause();
+                        service.pause(true)
                     }
-            break;
+                }
-
+                AudioManager.AUDIOFOCUS_LOSS_TRANSIENT -> {
-          case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
                     // Lost focus for a short time, but we have to stop
                     // playback. We don't release the media playback because playback
                     // is likely to resume
-            boolean wasPlaying = service.isPlaying();
+                    val wasPlaying = service.isPlaying
-            service.forcePause();
+                    service.pause(true)
-            service.setPausedByTransientLossOfFocus(wasPlaying);
+                    service.isPausedByTransientLossOfFocus = wasPlaying
-            break;
+                }
-
+                AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK -> {
-          case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
                     // Lost focus for a short time, but it's ok to keep playing
                     // at an attenuated level
-            removeMessages(MusicService.UNDUCK);
+                    removeMessages(MusicService.UNDUCK)
-            sendEmptyMessage(DUCK);
+                    sendEmptyMessage(MusicService.DUCK)
-            break;
-        }
-        break;
                 }
             }
         }
+    }
+
+    init {
+        mService = WeakReference(service)
+    }
+}

app/src/main/java/code/name/monkey/retromusic/service/playback/Playback.kt

@@ -14,6 +14,8 @@
 
 package code.name.monkey.retromusic.service.playback
 
+import code.name.monkey.retromusic.model.Song
+
 
 interface Playback {
 
@@ -23,7 +25,9 @@ interface Playback {
 
     val audioSessionId: Int
 
-    fun setDataSource(path: String, force: Boolean): Boolean
+    fun setDataSource(
+        song: Song, force: Boolean, completion: (success: Boolean) -> Unit,
+    )
 
     fun setNextDataSource(path: String?)
 
@@ -57,5 +61,7 @@ interface Playback {
         fun onTrackEnded()
 
         fun onTrackEndedWithCrossfade()
+
+        fun onPlayStateChanged()
     }
 }