Add PlayerService with ExoPlayer and MediaSession support

Author: osphvdhwj

external-player/src/main/java/org/newpipe/externalplayer/PlayerService.kt

@@ -0,0 +1,133 @@
+package org.newpipe.externalplayer
+
+import android.app.Notification
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import android.os.IBinder
+import androidx.lifecycle.LifecycleService
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import androidx.media.app.NotificationCompat.MediaStyle
+import android.support.v4.media.session.MediaSessionCompat
+import android.support.v4.media.MediaMetadataCompat
+import android.support.v4.media.session.PlaybackStateCompat
+import com.google.android.exoplayer2.ExoPlayer
+import com.google.android.exoplayer2.MediaItem
+
+class PlayerService : LifecycleService() {
+
+    companion object {
+        const val CHANNEL_ID = "external_player_channel"
+        const val NOTIF_ID = 1
+
+        const val ACTION_PLAY = "org.newpipe.externalplayer.action.PLAY"
+        const val ACTION_PAUSE = "org.newpipe.externalplayer.action.PAUSE"
+        const val ACTION_STOP = "org.newpipe.externalplayer.action.STOP"
+        const val ACTION_SET_URI = "org.newpipe.externalplayer.action.SET_URI"
+        const val EXTRA_URI = "uri"
+    }
+
+    private lateinit var mediaSession: MediaSessionCompat
+    private var player: ExoPlayer? = null
+    private lateinit var notificationManager: MediaNotificationManager
+
+    override fun onCreate() {
+        super.onCreate()
+        createChannel()
+        mediaSession = MediaSessionCompat(this, "ExternalPlayerSession").apply { isActive = true }
+        notificationManager = MediaNotificationManager(this)
+        initializePlayer()
+    }
+
+    private fun initializePlayer() {
+        if (player == null) {
+            player = ExoPlayer.Builder(this).build()
+            player?.addListener(object : com.google.android.exoplayer2.Player.Listener {
+                override fun onIsPlayingChanged(isPlaying: Boolean) {
+                    updatePlaybackState()
+                    startForegroundIfNeeded()
+                }
+            })
+        }
+    }
+
+    private fun startForegroundIfNeeded() {
+        val notification = notificationManager.buildNotification(player, mediaSession.sessionToken)
+        if (player?.isPlaying == true) {
+            startForeground(NOTIF_ID, notification)
+        } else {
+            val nm = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+            nm.notify(NOTIF_ID, notification)
+        }
+    }
+
+    private fun updatePlaybackState() {
+        val state = if (player?.isPlaying == true) PlaybackStateCompat.STATE_PLAYING else PlaybackStateCompat.STATE_PAUSED
+        val pos = player?.currentPosition ?: 0L
+        val playbackState = PlaybackStateCompat.Builder()
+            .setActions(
+                PlaybackStateCompat.ACTION_PLAY or
+                        PlaybackStateCompat.ACTION_PAUSE or
+                        PlaybackStateCompat.ACTION_PLAY_PAUSE or
+                        PlaybackStateCompat.ACTION_SEEK_TO or
+                        PlaybackStateCompat.ACTION_STOP
+            )
+            .setState(state, pos, 1.0f)
+            .build()
+        mediaSession.setPlaybackState(playbackState)
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        intent?.action?.let { action ->
+            when (action) {
+                ACTION_PLAY -> player?.play()
+                ACTION_PAUSE -> player?.pause()
+                ACTION_STOP -> {
+                    player?.stop()
+                    stopForeground(true)
+                    stopSelf()
+                }
+                ACTION_SET_URI -> {
+                    val uri = intent.getStringExtra(EXTRA_URI)
+                    if (uri != null) setMediaUri(uri)
+                }
+            }
+        }
+        startForegroundIfNeeded()
+        return START_STICKY
+    }
+
+    private fun setMediaUri(uri: String) {
+        initializePlayer()
+        val mediaItem = MediaItem.fromUri(uri)
+        player?.setMediaItem(mediaItem)
+        player?.prepare()
+        player?.play()
+        val metadataBuilder = MediaMetadataCompat.Builder()
+            .putString(MediaMetadataCompat.METADATA_KEY_TITLE, uri)
+        mediaSession.setMetadata(metadataBuilder.build())
+        updatePlaybackState()
+    }
+
+    override fun onDestroy() {
+        player?.release()
+        player = null
+        mediaSession.release()
+        super.onDestroy()
+    }
+
+    override fun onBind(intent: Intent): IBinder? {
+        super.onBind(intent)
+        return null
+    }
+
+    private fun createChannel() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val nm = getSystemService(NotificationManager::class.java)
+            val channel = NotificationChannel(CHANNEL_ID, "External Player", NotificationManager.IMPORTANCE_LOW)
+            nm.createNotificationChannel(channel)
+        }
+    }
+}