Add Playback Notification

Add a MediaStyle Notification for music playback.

app/src/main/java/org/oxycblt/auxio/MainActivity.kt

@@ -1,9 +1,11 @@
 package org.oxycblt.auxio
 
 import android.content.Context
+import android.content.Intent
 import android.util.AttributeSet
 import android.view.View
 import androidx.appcompat.app.AppCompatActivity
+import org.oxycblt.auxio.playback.PlaybackService
 import org.oxycblt.auxio.theme.accent
 
 // FIXME: Fix bug where fast navigation will break the animations and
@@ -16,4 +18,12 @@ class MainActivity : AppCompatActivity(R.layout.activity_main) {
 
         return super.onCreateView(name, context, attrs)
     }
+
+    override fun onStart() {
+        super.onStart()
+
+        Intent(this, PlaybackService::class.java).also {
+            this.startService(it)
+        }
+    }
 }

app/src/main/java/org/oxycblt/auxio/MainFragment.kt

@@ -1,6 +1,5 @@
 package org.oxycblt.auxio
 
-import android.content.Intent
 import android.os.Bundle
 import android.util.Log
 import android.view.LayoutInflater
@@ -16,7 +15,6 @@ import com.google.android.material.tabs.TabLayoutMediator
 import org.oxycblt.auxio.databinding.FragmentMainBinding
 import org.oxycblt.auxio.library.LibraryFragment
 import org.oxycblt.auxio.music.MusicStore
-import org.oxycblt.auxio.playback.PlaybackService
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.songs.SongsFragment
 import org.oxycblt.auxio.theme.accent
@@ -105,15 +103,6 @@ class MainFragment : Fragment() {
             }
         }
 
-        // Start the playback service [If not already]
-        if (!playbackModel.serviceStarted) {
-            Intent(requireContext(), PlaybackService::class.java).also {
-                requireContext().startService(it)
-            }
-
-            playbackModel.setServiceStatus(true)
-        }
-
         Log.d(this::class.simpleName, "Fragment Created.")
 
         return binding.root

app/src/main/java/org/oxycblt/auxio/music/coil/CoilUtils.kt

@@ -1,9 +1,11 @@
 package org.oxycblt.auxio.music.coil
 
 import android.content.Context
+import android.graphics.Bitmap
 import android.net.Uri
 import android.util.Log
 import android.widget.ImageView
+import androidx.core.graphics.drawable.toBitmap
 import androidx.databinding.BindingAdapter
 import coil.Coil
 import coil.request.ImageRequest
@@ -129,6 +131,17 @@ fun ImageView.bindGenreImage(genre: Genre) {
     Coil.imageLoader(context).enqueue(request)
 }
 
+// Get a bitmap for a song, onDone will be called when the bitmap is loaded.
+fun getBitmap(song: Song, context: Context, onDone: (Bitmap) -> Unit) {
+    Coil.enqueue(
+        ImageRequest.Builder(context)
+            .data(song.album.coverUri)
+            .error(R.drawable.ic_song)
+            .target { onDone(it.toBitmap()) }
+            .build()
+    )
+}
+
 // Get the base request used across the other functions.
 private fun getDefaultRequest(context: Context, imageView: ImageView): ImageRequest.Builder {
     return ImageRequest.Builder(context)

app/src/main/java/org/oxycblt/auxio/playback/PlaybackFragment.kt

@@ -138,6 +138,8 @@ class PlaybackFragment : Fragment(), SeekBar.OnSeekBarChangeListener {
                     binding.playbackLoop.imageTintList = accentColor
                     binding.playbackLoop.setImageResource(R.drawable.ic_loop)
                 }
+
+                else -> return@observe
             }
         }
 

app/src/main/java/org/oxycblt/auxio/playback/PlaybackNotificationHolder.kt

@@ -0,0 +1,73 @@
+package org.oxycblt.auxio.playback
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.content.Context
+import android.os.Build
+import android.support.v4.media.session.MediaSessionCompat
+import androidx.core.app.NotificationCompat
+import androidx.media.app.NotificationCompat.MediaStyle
+import org.oxycblt.auxio.R
+import org.oxycblt.auxio.music.Song
+import org.oxycblt.auxio.music.coil.getBitmap
+
+internal class PlaybackNotificationHolder {
+    private lateinit var mNotification: Notification
+
+    private lateinit var notificationManager: NotificationManager
+    private lateinit var baseNotification: NotificationCompat.Builder
+
+    fun init(context: Context, session: MediaSessionCompat) {
+        // Never run if the notification has already been created
+        if (!::mNotification.isInitialized) {
+            notificationManager =
+                context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+
+            // Create a notification channel if required
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                val channel = NotificationChannel(
+                    CHANNEL_ID,
+                    context.getString(R.string.label_notif_playback),
+                    NotificationManager.IMPORTANCE_DEFAULT
+                )
+                notificationManager.createNotificationChannel(channel)
+            }
+
+            baseNotification = NotificationCompat.Builder(context, CHANNEL_ID)
+                .setSmallIcon(R.drawable.ic_song)
+                .setStyle(MediaStyle().setMediaSession(session.sessionToken))
+                .setChannelId(CHANNEL_ID)
+                .setShowWhen(false)
+                .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
+
+            mNotification = baseNotification.build()
+        }
+    }
+
+    fun setMetadata(song: Song, playbackService: PlaybackService) {
+        // Set the basic metadata since MediaStyle wont do it yourself.
+        // Fun Fact: The documentation still says that MediaStyle will handle metadata changes
+        // from MediaSession, even though it doesn't. After 6 years.
+        baseNotification
+            .setContentTitle(song.name)
+            .setContentText(
+                playbackService.getString(
+                    R.string.format_info,
+                    song.album.artist.name,
+                    song.album.name
+                )
+            )
+
+        getBitmap(song, playbackService) {
+            baseNotification.setLargeIcon(it)
+            mNotification = baseNotification.build()
+            playbackService.startForeground(NOTIFICATION_ID, mNotification)
+        }
+    }
+
+    companion object {
+        const val CHANNEL_ID = "CHANNEL_AUXIO_PLAYBACK"
+        const val NOTIFICATION_ID = 0xA0A0
+    }
+}

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

@@ -1,8 +1,5 @@
 package org.oxycblt.auxio.playback
 
-import android.app.Notification
-import android.app.NotificationChannel
-import android.app.NotificationManager
 import android.app.Service
 import android.bluetooth.BluetoothDevice
 import android.content.BroadcastReceiver
@@ -13,11 +10,12 @@ import android.media.AudioManager
 import android.os.Build
 import android.os.IBinder
 import android.os.Parcelable
+import android.support.v4.media.MediaMetadataCompat
 import android.support.v4.media.session.MediaSessionCompat
 import android.util.Log
 import android.view.KeyEvent
-import androidx.core.app.NotificationCompat
 import com.google.android.exoplayer2.C
+import com.google.android.exoplayer2.ExoPlaybackException
 import com.google.android.exoplayer2.MediaItem
 import com.google.android.exoplayer2.Player
 import com.google.android.exoplayer2.SimpleExoPlayer
@@ -32,49 +30,38 @@ import kotlinx.coroutines.flow.conflate
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.takeWhile
 import kotlinx.coroutines.launch
-import org.oxycblt.auxio.R
 import org.oxycblt.auxio.music.Song
+import org.oxycblt.auxio.music.coil.getBitmap
 import org.oxycblt.auxio.music.toURI
 import org.oxycblt.auxio.playback.state.LoopMode
 import org.oxycblt.auxio.playback.state.PlaybackStateCallback
 import org.oxycblt.auxio.playback.state.PlaybackStateManager
 
-private const val CHANNEL_ID = "CHANNEL_AUXIO_PLAYBACK"
-private const val NOTIF_ID = 0xA0A0
-private const val CONNECTED = 1
-private const val DISCONNECTED = 0
-
 // A Service that manages the single ExoPlayer instance and manages the system-side
 // aspects of playback.
 class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
-    // TODO: Use the ExoPlayer queue functionality [To an extent]? Could make things faster.
     private val player: SimpleExoPlayer by lazy {
-        val p = SimpleExoPlayer.Builder(applicationContext).build()
+        SimpleExoPlayer.Builder(applicationContext).build()
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
-            p.experimentalSetOffloadSchedulingEnabled(true)
-        }
-        p.addListener(this)
-        p
     }
 
     private val playbackManager = PlaybackStateManager.getInstance()
     private lateinit var mediaSession: MediaSessionCompat
     private lateinit var systemReceiver: SystemEventReceiver
-    private var changeIsFromSystem = false
+    private val notificationHolder = PlaybackNotificationHolder()
+
+    private var changeIsFromAudioFocus = true
 
     private val serviceJob = Job()
     private val serviceScope = CoroutineScope(
         serviceJob + Dispatchers.Main
     )
 
-    private lateinit var notification: Notification
-
     // --- SERVICE OVERRIDES ---
 
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
         Log.d(this::class.simpleName, "Service is active.")
 
-        return START_STICKY
+        return START_NOT_STICKY
     }
 
     override fun onBind(intent: Intent): IBinder? = null
@@ -82,16 +69,8 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
     override fun onCreate() {
         super.onCreate()
 
-        // Set up the media button callbacks
+        // --- PLAYER SETUP ---
-        mediaSession = MediaSessionCompat(this, packageName).apply {
+        player.addListener(this)
-            isActive = true
-        }
-
-        val connector = MediaSessionConnector(mediaSession)
-        connector.setPlayer(player)
-        connector.setMediaButtonEventHandler { _, _, mediaButtonEvent ->
-            handleMediaButtonEvent(mediaButtonEvent)
-        }
 
         // Set up AudioFocus/AudioAttributes
         player.setAudioAttributes(
@@ -102,7 +81,31 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
             true
         )
 
-        notification = createNotification()
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            player.experimentalSetOffloadSchedulingEnabled(true)
+        }
+
+        // --- PLAYBACKSTATEMANAGER SETUP ---
+
+        playbackManager.addCallback(this)
+
+        if (playbackManager.song != null) {
+            restorePlayer()
+        }
+
+        // --- SYSTEM RECEIVER SETUP ---
+
+        // Set up the media button callbacks
+        mediaSession = MediaSessionCompat(this, packageName).apply {
+            isActive = true
+
+            MediaSessionConnector(this).apply {
+                setPlayer(player)
+                setMediaButtonEventHandler { _, _, mediaButtonEvent ->
+                    handleMediaButtonEvent(mediaButtonEvent)
+                }
+            }
+        }
 
         // Set up callback for system events
         systemReceiver = SystemEventReceiver()
@@ -115,7 +118,9 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
             registerReceiver(systemReceiver, this)
         }
 
-        playbackManager.addCallback(this)
+        // --- NOTIFICATION SETUP ---
+
+        notificationHolder.init(applicationContext, mediaSession)
     }
 
     override fun onDestroy() {
@@ -136,6 +141,8 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
     // --- PLAYER EVENT LISTENER OVERRIDES ---
 
     override fun onPlaybackStateChanged(state: Int) {
+        changeIsFromAudioFocus = false
+
         if (state == Player.STATE_ENDED) {
             playbackManager.next()
         } else if (state == Player.STATE_READY) {
@@ -144,13 +151,11 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
     }
 
     override fun onIsPlayingChanged(isPlaying: Boolean) {
-        // If the change to playing occurred from the system instead of PlaybackStateManager, then
+        // Only sync the playing status with PlaybackStateManager if the change occurred
-        // sync the playing value to PlaybackStateManager to keep it up ton date.
+        // from an Audio Focus change. Nowhere else.
-        if (isPlaying != playbackManager.isPlaying && changeIsFromSystem) {
+        if (isPlaying != playbackManager.isPlaying && changeIsFromAudioFocus) {
             playbackManager.setPlayingStatus(isPlaying)
         }
-
-        changeIsFromSystem = true
     }
 
     override fun onMediaItemTransition(mediaItem: MediaItem?, reason: Int) {
@@ -162,30 +167,46 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
         }
     }
 
+    override fun onPlayerError(error: ExoPlaybackException) {
+        // If there's any issue, just go to the next song.
+        playbackManager.next()
+    }
+
+    override fun onPositionDiscontinuity(reason: Int) {
+        if (reason == Player.DISCONTINUITY_REASON_SEEK) {
+            playbackManager.setPosition(player.currentPosition / 1000)
+        }
+    }
+
     // --- PLAYBACK STATE CALLBACK OVERRIDES ---
 
     override fun onSongUpdate(song: Song?) {
-        changeIsFromSystem = false
+        changeIsFromAudioFocus = false
 
         song?.let {
             val item = MediaItem.fromUri(it.id.toURI())
+
             player.setMediaItem(item)
             player.prepare()
             player.play()
 
+            uploadMetadataToSession(it)
+            notificationHolder.setMetadata(playbackManager.song!!, this)
+
             return
         }
 
+        // Stop playing/the notification if there's nothing to play.
         player.stop()
+        stopForeground(true)
     }
 
     override fun onPlayingUpdate(isPlaying: Boolean) {
-        changeIsFromSystem = false
+        changeIsFromAudioFocus = false
 
         if (isPlaying && !player.isPlaying) {
             player.play()
 
-            startForeground(NOTIF_ID, notification)
             startPollingPosition()
         } else {
             player.pause()
@@ -196,7 +217,7 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
     }
 
     override fun onLoopUpdate(mode: LoopMode) {
-        changeIsFromSystem = false
+        changeIsFromAudioFocus = false
 
         when (mode) {
             LoopMode.NONE -> {
@@ -209,16 +230,44 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
     }
 
     override fun onSeekConfirm(position: Long) {
-        changeIsFromSystem = false
+        changeIsFromAudioFocus = false
 
         player.seekTo(position * 1000)
     }
 
     // --- OTHER FUNCTIONS ---
 
+    private fun restorePlayer() {
+        playbackManager.song?.let {
+            val item = MediaItem.fromUri(it.id.toURI())
+            player.setMediaItem(item)
+            player.prepare()
+            player.play()
+
+            notificationHolder.setMetadata(it, this)
+        }
+    }
+
+    private fun uploadMetadataToSession(song: Song) {
+        val builder = MediaMetadataCompat.Builder()
+            .putString(MediaMetadataCompat.METADATA_KEY_TITLE, song.name)
+            .putString(MediaMetadataCompat.METADATA_KEY_DISPLAY_TITLE, song.name)
+            .putString(MediaMetadataCompat.METADATA_KEY_ARTIST, song.album.artist.name)
+            .putString(MediaMetadataCompat.METADATA_KEY_AUTHOR, song.album.artist.name)
+            .putString(MediaMetadataCompat.METADATA_KEY_COMPOSER, song.album.artist.name)
+            .putString(MediaMetadataCompat.METADATA_KEY_ALBUM_ARTIST, song.album.artist.name)
+            .putString(MediaMetadataCompat.METADATA_KEY_ALBUM, song.album.name)
+            .putLong(MediaMetadataCompat.METADATA_KEY_DURATION, song.duration)
+
+        getBitmap(song, this) {
+            builder.putBitmap(MediaMetadataCompat.METADATA_KEY_ALBUM_ART, it)
+            mediaSession.setMetadata(builder.build())
+        }
+    }
+
     // Awful Hack to get position polling to work, as exoplayer does not provide any
     // onPositionChanged callback for some inane reason.
-    // FIXME: There has to be a better way of polling positions.
+    // TODO: MediaSession might have a callback for positions. Idk.
     private fun pollCurrentPosition() = flow {
         while (player.isPlaying) {
             emit(player.currentPosition)
@@ -274,35 +323,6 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
         return false
     }
 
-    // Create a notification
-    // TODO: Spin this off into its own object!
-    private fun createNotification(): Notification {
-        val notificationManager =
-            getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
-
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-            val channel = NotificationChannel(
-                CHANNEL_ID,
-                getString(R.string.label_notif_playback),
-                NotificationManager.IMPORTANCE_DEFAULT
-            )
-            notificationManager.createNotificationChannel(channel)
-        }
-        // TODO: Placeholder, implement proper media controls.
-        val notif = NotificationCompat.Builder(
-            applicationContext,
-            CHANNEL_ID
-        )
-            .setSmallIcon(R.drawable.ic_song)
-            .setContentTitle(getString(R.string.app_name))
-            .setContentText(getString(R.string.label_is_playing))
-            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
-            .setChannelId(CHANNEL_ID)
-            .build()
-
-        return notif
-    }
-
     // BroadcastReceiver for receiving system events [E.G Headphones connected/disconnected]
     private inner class SystemEventReceiver : BroadcastReceiver() {
         override fun onReceive(context: Context, intent: Intent) {
@@ -348,4 +368,9 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
             }
         }
     }
+
+    companion object {
+        private const val DISCONNECTED = 0
+        private const val CONNECTED = 1
+    }
 }

app/src/main/java/org/oxycblt/auxio/playback/PlaybackViewModel.kt

@@ -48,9 +48,6 @@ class PlaybackViewModel : ViewModel(), PlaybackStateCallback {
     private val mIsSeeking = MutableLiveData(false)
     val isSeeking: LiveData<Boolean> get() = mIsSeeking
 
-    private var mServiceStarted = false
-    val serviceStarted: Boolean get() = mServiceStarted
-
     val formattedPosition = Transformations.map(mPosition) {
         it.toDuration()
     }
@@ -190,10 +187,6 @@ class PlaybackViewModel : ViewModel(), PlaybackStateCallback {
         mIsSeeking.value = value
     }
 
-    fun setServiceStatus(value: Boolean) {
-        mServiceStarted = value
-    }
-
     // --- OVERRIDES ---
 
     override fun onCleared() {

app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateManager.kt

@@ -11,17 +11,19 @@ import org.oxycblt.auxio.music.Song
 import kotlin.random.Random
 
 // The manager of the current playback state [Current Song, Queue, Shuffling]
-// Never use this for ANYTHING UI related, that's what PlaybackViewModel is for.
+// This class is for sole use by the classes in /playback/.
-// Yes, I know MediaSessionCompat and friends exist, but I like having full control over the
+// If you want to add system-side things, add to PlaybackService.
-// playback state instead of dealing with android's likely buggy code.
+// If you want to add ui-side things, add to PlaybackViewModel.
-class PlaybackStateManager {
+// [Yes, I know MediaSessionCompat exists, but I like having full control over the
+// playback state instead of dealing with android's likely buggy code.]
+internal class PlaybackStateManager {
     // Playback
     private var mSong: Song? = null
         set(value) {
             field = value
             callbacks.forEach { it.onSongUpdate(value) }
         }
-    private var mPosition: Long = 0
+    private var mPosition: Long = 0 // TODO: Consider using millis instead of seconds?
         set(value) {
             field = value
             callbacks.forEach { it.onPositionUpdate(value) }

app/src/main/res/values/strings.xml

@@ -56,6 +56,7 @@
     <string name="placeholder_genre">Unknown Genre</string>
     <string name="placeholder_artist">Unknown Artist</string>
     <string name="placeholder_album">Unknown Album</string>
+    <string name="placeholder_song">Unknown Song</string>
     <string name="placeholder_no_date">No Date</string>
 
     <!-- Format Namespace | Value formatting/plurals -->