playback: cleanup components

Fix miscellanious bugs and clean the component code.

Currently the components are in a strange state. They are a big ball of
mud with inconsistent lifecycles and callbacks. I want to find a way to
unify them under a single lifecycle, but the competing nature of them
makes this extremely difficult.

app/src/main/java/org/oxycblt/auxio/playback/system/MediaSessionComponent.kt

@@ -23,38 +23,50 @@ import android.os.SystemClock
 import android.support.v4.media.MediaMetadataCompat
 import android.support.v4.media.session.MediaSessionCompat
 import android.support.v4.media.session.PlaybackStateCompat
+import androidx.media.session.MediaButtonReceiver
 import com.google.android.exoplayer2.Player
 import org.oxycblt.auxio.coil.loadBitmap
 import org.oxycblt.auxio.music.MusicParent
 import org.oxycblt.auxio.music.Song
 import org.oxycblt.auxio.playback.state.PlaybackStateManager
 import org.oxycblt.auxio.playback.state.RepeatMode
+import org.oxycblt.auxio.settings.SettingsManager
 import org.oxycblt.auxio.util.logD
 
 /**
- * Nightmarish class that coordinates communication between [MediaSessionCompat], [Player], and
- * [PlaybackStateManager].
  */
-class PlaybackSessionConnector(
+class MediaSessionComponent(private val context: Context, private val player: Player) :
-    private val context: Context,
+    PlaybackStateManager.Callback,
-    private val player: Player,
+    Player.Listener,
-    private val mediaSession: MediaSessionCompat
+    SettingsManager.Callback,
-) : PlaybackStateManager.Callback, Player.Listener, MediaSessionCompat.Callback() {
+    MediaSessionCompat.Callback() {
     private val playbackManager = PlaybackStateManager.getInstance()
-    private val emptyMetadata = MediaMetadataCompat.Builder().build()
+    private val settingsManager = SettingsManager.getInstance()
+
+    private val mediaSession = MediaSessionCompat(context, context.packageName)
+
+    val token: MediaSessionCompat.Token
+        get() = mediaSession.sessionToken
 
     init {
         mediaSession.setCallback(this)
         playbackManager.addCallback(this)
+        settingsManager.addCallback(this)
         player.addListener(this)
 
         onSongChanged(playbackManager.song)
         onPlayingChanged(playbackManager.isPlaying)
     }
 
+    fun handleMediaButtonIntent(intent: Intent) {
+        MediaButtonReceiver.handleIntent(mediaSession, intent)
+    }
+
     fun release() {
         playbackManager.removeCallback(this)
+        settingsManager.removeCallback(this)
         player.removeListener(this)
+        mediaSession.release()
     }
 
     // --- MEDIASESSION CALLBACKS ---
@@ -111,10 +123,6 @@ class PlaybackSessionConnector(
         onSongChanged(playbackManager.song)
     }
 
-    override fun onQueueChanged(index: Int, queue: List<Song>) {
-        onSongChanged(playbackManager.song)
-    }
-
     override fun onNewPlayback(index: Int, queue: List<Song>, parent: MusicParent?) {
         onSongChanged(playbackManager.song)
     }
@@ -152,18 +160,42 @@ class PlaybackSessionConnector(
         invalidateSessionState()
     }
 
-    // -- EXOPLAYER CALLBACKS ---
+    override fun onRepeatChanged(repeatMode: RepeatMode) {
+        mediaSession.setRepeatMode(
+            when (repeatMode) {
+                RepeatMode.NONE -> PlaybackStateCompat.REPEAT_MODE_NONE
+                RepeatMode.TRACK -> PlaybackStateCompat.REPEAT_MODE_ONE
+                RepeatMode.ALL -> PlaybackStateCompat.REPEAT_MODE_ALL
+            })
+    }
 
-    override fun onEvents(player: Player, events: Player.Events) {
+    override fun onShuffledChanged(isShuffled: Boolean) {
-        if (events.containsAny(
+        mediaSession.setShuffleMode(
-            Player.EVENT_POSITION_DISCONTINUITY,
+            if (isShuffled) {
-            Player.EVENT_PLAYBACK_STATE_CHANGED,
+                PlaybackStateCompat.SHUFFLE_MODE_ALL
-            Player.EVENT_PLAY_WHEN_READY_CHANGED,
+            } else {
-            Player.EVENT_IS_PLAYING_CHANGED,
+                PlaybackStateCompat.SHUFFLE_MODE_NONE
-            Player.EVENT_REPEAT_MODE_CHANGED,
+            })
-            Player.EVENT_PLAYBACK_PARAMETERS_CHANGED)) {
+    }
-            invalidateSessionState()
+
-        }
+    // -- SETTINGSMANAGER CALLBACKS --
+
+    override fun onShowCoverUpdate(showCovers: Boolean) {
+        onSongChanged(playbackManager.song)
+    }
+
+    override fun onQualityCoverUpdate(doQualityCovers: Boolean) {
+        onSongChanged(playbackManager.song)
+    }
+
+    // -- EXOPLAYER CALLBACKS --
+
+    override fun onPositionDiscontinuity(
+        oldPosition: Player.PositionInfo,
+        newPosition: Player.PositionInfo,
+        reason: Int
+    ) {
+        invalidateSessionState()
     }
 
     // --- MISC ---
@@ -205,6 +237,8 @@ class PlaybackSessionConnector(
     }
 
     companion object {
+        private val emptyMetadata = MediaMetadataCompat.Builder().build()
+
         const val ACTIONS =
             PlaybackStateCompat.ACTION_PLAY or
                 PlaybackStateCompat.ACTION_PAUSE or

app/src/main/java/org/oxycblt/auxio/playback/system/NotificationComponent.kt

@@ -27,24 +27,38 @@ import androidx.annotation.DrawableRes
 import androidx.core.app.NotificationCompat
 import androidx.media.app.NotificationCompat.MediaStyle
 import org.oxycblt.auxio.BuildConfig
+import org.oxycblt.auxio.IntegerTable
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.coil.loadBitmap
 import org.oxycblt.auxio.music.MusicParent
 import org.oxycblt.auxio.music.Song
 import org.oxycblt.auxio.playback.state.RepeatMode
+import org.oxycblt.auxio.util.getSystemServiceSafe
 import org.oxycblt.auxio.util.newBroadcastIntent
 import org.oxycblt.auxio.util.newMainIntent
 
 /**
- * The unified notification for [PlaybackService]. This is not self-sufficient, updates have to be
+ * The unified notification for [PlaybackService]. Due to the nature of how this notification is
- * delivered manually.
+ * used, it is *not self-sufficient*. Updates have to be delivered manually, as to prevent state
+ * inconsistency when the foreground state is started.
  * @author OxygenCobalt
  */
 @SuppressLint("RestrictedApi")
-class PlaybackNotification
+class NotificationComponent(private val context: Context, sessionToken: MediaSessionCompat.Token) :
-private constructor(private val context: Context, mediaToken: MediaSessionCompat.Token) :
     NotificationCompat.Builder(context, CHANNEL_ID) {
+    private val notificationManager = context.getSystemServiceSafe(NotificationManager::class)
+
     init {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val channel =
+                NotificationChannel(
+                    CHANNEL_ID,
+                    context.getString(R.string.info_channel_name),
+                    NotificationManager.IMPORTANCE_DEFAULT)
+
+            notificationManager.createNotificationChannel(channel)
+        }
+
         setSmallIcon(R.drawable.ic_auxio)
         setCategory(NotificationCompat.CATEGORY_SERVICE)
         setShowWhen(false)
@@ -58,11 +72,11 @@ private constructor(private val context: Context, mediaToken: MediaSessionCompat
         addAction(buildAction(context, PlaybackService.ACTION_SKIP_NEXT, R.drawable.ic_skip_next))
         addAction(buildAction(context, PlaybackService.ACTION_EXIT, R.drawable.ic_exit))
 
-        setStyle(MediaStyle().setMediaSession(mediaToken).setShowActionsInCompactView(1, 2, 3))
+        setStyle(MediaStyle().setMediaSession(sessionToken).setShowActionsInCompactView(1, 2, 3))
+    }
 
-        // Don't connect to PlaybackStateManager here. This is because it's possible for this
+    fun renotify() {
-        // notification to not be updated by PlaybackStateManager before PlaybackService pushes
+        notificationManager.notify(IntegerTable.NOTIFICATION_CODE, build())
-        // the notification, resulting in invalid metadata.
     }
 
     // --- STATE FUNCTIONS ---
@@ -71,13 +85,15 @@ private constructor(private val context: Context, mediaToken: MediaSessionCompat
      * Set the metadata of the notification using [song].
      * @param onDone What to do when the loading of the album art is finished
      */
-    fun setMetadata(song: Song, onDone: () -> Unit) {
+    fun updateMetadata(song: Song, parent: MusicParent?, onDone: () -> Unit) {
         setContentTitle(song.resolveName(context))
         setContentText(song.resolveIndividualArtistName(context))
 
-        // On older versions of android [API <24], show the song's album on the subtext instead of
+        // Starting in API 24, the subtext field changed semantics from being below the content
-        // the current mode, as that makes more sense for the old style of media notifications.
+        // text to being above the title.
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            setSubText(parent?.resolveName(context) ?: context.getString(R.string.lbl_all_songs))
+        } else {
             setSubText(song.resolveName(context))
         }
 
@@ -90,28 +106,20 @@ private constructor(private val context: Context, mediaToken: MediaSessionCompat
     }
 
     /** Set the playing icon on the notification */
-    fun setPlaying(isPlaying: Boolean) {
+    fun updatePlaying(isPlaying: Boolean) {
         mActions[2] = buildPlayPauseAction(context, isPlaying)
     }
 
     /** Update the first action to reflect the [repeatMode] given. */
-    fun setRepeatMode(repeatMode: RepeatMode) {
+    fun updateRepeatMode(repeatMode: RepeatMode) {
         mActions[0] = buildRepeatAction(context, repeatMode)
     }
 
     /** Update the first action to reflect whether the queue is shuffled or not */
-    fun setShuffled(isShuffled: Boolean) {
+    fun updateShuffled(isShuffled: Boolean) {
         mActions[0] = buildShuffleAction(context, isShuffled)
     }
 
-    /** Apply the current [parent] to the header of the notification. */
-    fun setParent(parent: MusicParent?) {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) return
-
-        // A blank parent always means that the mode is ALL_SONGS
-        setSubText(parent?.resolveName(context) ?: context.getString(R.string.lbl_all_songs))
-    }
-
     // --- NOTIFICATION ACTION BUILDERS ---
 
     private fun buildPlayPauseAction(
@@ -161,24 +169,5 @@ private constructor(private val context: Context, mediaToken: MediaSessionCompat
 
     companion object {
         const val CHANNEL_ID = BuildConfig.APPLICATION_ID + ".channel.PLAYBACK"
-
-        /** Build a new instance of [PlaybackNotification]. */
-        fun from(
-            context: Context,
-            notificationManager: NotificationManager,
-            mediaSession: MediaSessionCompat
-        ): PlaybackNotification {
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-                val channel =
-                    NotificationChannel(
-                        CHANNEL_ID,
-                        context.getString(R.string.info_channel_name),
-                        NotificationManager.IMPORTANCE_DEFAULT)
-
-                notificationManager.createNotificationChannel(channel)
-            }
-
-            return PlaybackNotification(context, mediaSession.sessionToken)
-        }
     }
 }

app/src/main/java/org/oxycblt/auxio/playback/system/PlaybackService.kt

@@ -17,19 +17,13 @@
  
 package org.oxycblt.auxio.playback.system
 
-import android.app.NotificationManager
 import android.app.Service
 import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
-import android.content.pm.ServiceInfo
-import android.graphics.Bitmap
 import android.media.AudioManager
-import android.os.Build
 import android.os.IBinder
-import android.support.v4.media.session.MediaSessionCompat
-import androidx.media.session.MediaButtonReceiver
 import com.google.android.exoplayer2.C
 import com.google.android.exoplayer2.ExoPlayer
 import com.google.android.exoplayer2.MediaItem
@@ -56,7 +50,6 @@ import org.oxycblt.auxio.music.Song
 import org.oxycblt.auxio.playback.state.PlaybackStateManager
 import org.oxycblt.auxio.playback.state.RepeatMode
 import org.oxycblt.auxio.settings.SettingsManager
-import org.oxycblt.auxio.util.getSystemServiceSafe
 import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.widgets.WidgetController
 import org.oxycblt.auxio.widgets.WidgetProvider
@@ -71,25 +64,16 @@ import org.oxycblt.auxio.widgets.WidgetProvider
  * This service relies on [PlaybackStateManager.Callback] and [SettingsManager.Callback], so
  * therefore there's no need to bind to it to deliver commands.
  * @author OxygenCobalt
- *
- * TODO: Move all external exposal from passing around PlaybackStateManager to passing around the
- * MediaMetadata instance. Generally makes it easier to encapsulate this class.
- *
- * TODO: Move hasPlayed to here as well.
  */
 class PlaybackService :
     Service(), Player.Listener, PlaybackStateManager.Callback, SettingsManager.Callback {
     // Player components
     private lateinit var player: ExoPlayer
-    private lateinit var mediaSession: MediaSessionCompat
-    private lateinit var connector: PlaybackSessionConnector
     private val replayGainProcessor = ReplayGainAudioProcessor()
 
-    // Notification components
-    private lateinit var notification: PlaybackNotification
-    private lateinit var notificationManager: NotificationManager
-
     // System backend components
+    private lateinit var notificationComponent: NotificationComponent
+    private lateinit var mediaSessionComponent: MediaSessionComponent
     private lateinit var widgets: WidgetController
     private val systemReceiver = PlaybackReceiver()
 
@@ -126,8 +110,8 @@ class PlaybackService :
         // --- SYSTEM SETUP ---
 
         widgets = WidgetController(this)
-        mediaSession = MediaSessionCompat(this, packageName).apply { isActive = true }
+        mediaSessionComponent = MediaSessionComponent(this, player)
-        connector = PlaybackSessionConnector(this, player, mediaSession)
+        notificationComponent = NotificationComponent(this, mediaSessionComponent.token)
 
         // Then the notification/headset callbacks
         IntentFilter().apply {
@@ -145,11 +129,6 @@ class PlaybackService :
             registerReceiver(systemReceiver, this)
         }
 
-        // --- NOTIFICATION SETUP ---
-
-        notificationManager = getSystemServiceSafe(NotificationManager::class)
-        notification = PlaybackNotification.from(this, notificationManager, mediaSession)
-
         // --- PLAYBACKSTATEMANAGER SETUP ---
 
         playbackManager.addCallback(this)
@@ -168,7 +147,7 @@ class PlaybackService :
         if (intent.action == Intent.ACTION_MEDIA_BUTTON) {
             // Workaround to get GadgetBridge and other apps that blindly query for
             // ACTION_MEDIA_BUTTON working.
-            MediaButtonReceiver.handleIntent(mediaSession, intent)
+            mediaSessionComponent.handleMediaButtonIntent(intent)
         }
 
         return START_NOT_STICKY
@@ -188,8 +167,7 @@ class PlaybackService :
 
         serviceJob.cancel()
         player.release()
-        connector.release()
+        mediaSessionComponent.release()
-        mediaSession.release()
         widgets.release()
 
         playbackManager.removeCallback(this)
@@ -273,7 +251,8 @@ class PlaybackService :
             logD("Setting player to ${song.rawName}")
             player.setMediaItem(MediaItem.fromUri(song.uri))
             player.prepare()
-            notification.setMetadata(song, ::startForegroundOrNotify)
+            notificationComponent.updateMetadata(
+                song, playbackManager.parent, ::startForegroundOrNotify)
             return
         }
 
@@ -285,20 +264,20 @@ class PlaybackService :
 
     override fun onPlayingChanged(isPlaying: Boolean) {
         player.playWhenReady = isPlaying
-        notification.setPlaying(isPlaying)
+        notificationComponent.updatePlaying(isPlaying)
         startForegroundOrNotify()
     }
 
     override fun onRepeatChanged(repeatMode: RepeatMode) {
         if (!settingsManager.useAltNotifAction) {
-            notification.setRepeatMode(repeatMode)
+            notificationComponent.updateRepeatMode(repeatMode)
             startForegroundOrNotify()
         }
     }
 
     override fun onShuffledChanged(isShuffled: Boolean) {
         if (settingsManager.useAltNotifAction) {
-            notification.setShuffled(isShuffled)
+            notificationComponent.updateShuffled(isShuffled)
             startForegroundOrNotify()
         }
     }
@@ -309,18 +288,11 @@ class PlaybackService :
 
     // --- SETTINGSMANAGER OVERRIDES ---
 
-    override fun onColorizeNotifUpdate(doColorize: Boolean) {
-        playbackManager.song?.let { song ->
-            connector.onSongChanged(song)
-            notification.setMetadata(song, ::startForegroundOrNotify)
-        }
-    }
-
     override fun onNotifActionUpdate(useAltAction: Boolean) {
         if (useAltAction) {
-            notification.setShuffled(playbackManager.isShuffled)
+            notificationComponent.updateShuffled(playbackManager.isShuffled)
         } else {
-            notification.setRepeatMode(playbackManager.repeatMode)
+            notificationComponent.updateRepeatMode(playbackManager.repeatMode)
         }
 
         startForegroundOrNotify()
@@ -328,14 +300,15 @@ class PlaybackService :
 
     override fun onShowCoverUpdate(showCovers: Boolean) {
         playbackManager.song?.let { song ->
-            connector.onSongChanged(song)
+            notificationComponent.updateMetadata(
-            notification.setMetadata(song, ::startForegroundOrNotify)
+                song, playbackManager.parent, ::startForegroundOrNotify)
         }
     }
 
     override fun onQualityCoverUpdate(doQualityCovers: Boolean) {
         playbackManager.song?.let { song ->
-            notification.setMetadata(song, ::startForegroundOrNotify)
+            notificationComponent.updateMetadata(
+                song, playbackManager.parent, ::startForegroundOrNotify)
         }
     }
 
@@ -398,20 +371,12 @@ class PlaybackService :
             logD("Starting foreground/notifying")
 
             if (!isForeground) {
-                // Specify that this is a media service, if supported.
+                startForeground(IntegerTable.NOTIFICATION_CODE, notificationComponent.build())
-                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
-                    startForeground(
-                        IntegerTable.NOTIFICATION_CODE,
-                        notification.build(),
-                        ServiceInfo.FOREGROUND_SERVICE_TYPE_MEDIA_PLAYBACK)
-                } else {
-                    startForeground(IntegerTable.NOTIFICATION_CODE, notification.build())
-                }
 
                 isForeground = true
             } else {
                 // If we are already in foreground just update the notification
-                notificationManager.notify(IntegerTable.NOTIFICATION_CODE, notification.build())
+                notificationComponent.renotify()
             }
         }
     }
@@ -424,18 +389,6 @@ class PlaybackService :
         saveScope.launch { playbackManager.saveStateToDatabase(this@PlaybackService) }
     }
 
-    data class Metadata(
-        val title: String,
-        val album: String,
-        val artist: String,
-        val album_artist: String,
-        val genre: String,
-        val parent: String,
-        val year: Int,
-        val track: Int?,
-        val albumCover: Bitmap
-    )
-
     /** A [BroadcastReceiver] for receiving general playback events from the system. */
     private inner class PlaybackReceiver : BroadcastReceiver() {
         private var initialHeadsetPlugEventHandled = false

app/src/main/java/org/oxycblt/auxio/widgets/WidgetController.kt

@@ -66,10 +66,6 @@ class WidgetController(private val context: Context) :
         widget.update(context, playbackManager)
     }
 
-    override fun onQueueChanged(index: Int, queue: List<Song>) {
-        widget.update(context, playbackManager)
-    }
-
     override fun onNewPlayback(index: Int, queue: List<Song>, parent: MusicParent?) {
         widget.update(context, playbackManager)
     }