fix(android): foreground issues & notification icon (#2048)

* fix(android): foreground issues (close #2045)

- move execution of foregrounding and backgrounding to NotificationState.POSTED in order to avoid race condition where notificationId has not been set yet
- avoid comparing to player states that don’t affect foregrounding, by ignoring LOADING, BUFFERING and READY states – all of which can occur both when playing or while paused
- also avoid the initial IDLE state, since we are only interested when the player would become idle (i.e. all tracks were removed)
- ENDED state should also cause foregrounding to stop (without removing notification)

* Fix: Add missing icon to notification (close #2049)

Using `ExoPlayerR.drawable.exo_notification_small_icon` which is exoplayer’s default notification icon.

android/src/main/java/com/doublesymmetry/trackplayer/service/MusicService.kt

@@ -32,6 +32,7 @@ import com.doublesymmetry.trackplayer.utils.BundleUtils.setRating
 import com.facebook.react.HeadlessJsTaskService
 import com.facebook.react.bridge.Arguments
 import com.facebook.react.jstasks.HeadlessJsTaskConfig
+import com.google.android.exoplayer2.ui.R as ExoPlayerR
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.flow
 import java.util.concurrent.TimeUnit
@@ -114,6 +115,7 @@ class MusicService : HeadlessJsTaskService() {
  val notificationBuilder = NotificationCompat.Builder(this, name)
  .setPriority(PRIORITY_LOW)
  .setCategory(Notification.CATEGORY_SERVICE)
+ .setSmallIcon(ExoPlayerR.drawable.exo_notification_small_icon)
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
  notificationBuilder.setForegroundServiceBehavior(NotificationCompat.FOREGROUND_SERVICE_IMMEDIATE)
  }
@@ -491,6 +493,8 @@ class MusicService : HeadlessJsTaskService() {
  // Implementation based on https://github.com/Automattic/pocket-casts-android/blob/ee8da0c095560ef64a82d3a31464491b8d713104/modules/services/repositories/src/main/java/au/com/shiftyjelly/pocketcasts/repositories/playback/PlaybackService.kt#L218
  var notificationId: Int? = null
  var notification: Notification? = null
+ var stopForegroundWhenNotOngoing = false
+ var removeNotificationWhenNotOngoing = false
 
  fun startForegroundIfNecessary() {
  if (isForegroundService()) {
@@ -528,34 +532,52 @@ class MusicService : HeadlessJsTaskService() {
  }
  }
 
+ scope.launch {
+ val BACKGROUNDABLE_STATES = listOf(
+ AudioPlayerState.IDLE,
+ AudioPlayerState.ENDED,
+ AudioPlayerState.STOPPED,
+ AudioPlayerState.ERROR,
+ AudioPlayerState.PAUSED
+ )
+ val REMOVABLE_STATES = listOf(
+ AudioPlayerState.IDLE,
+ AudioPlayerState.STOPPED,
+ AudioPlayerState.ERROR
+ )
+ val LOADING_STATES = listOf(
+ AudioPlayerState.LOADING,
+ AudioPlayerState.READY,
+ AudioPlayerState.BUFFERING
+ )
+ var stateCount = 0
+ event.stateChange.collect {
+ stateCount++
+ if (it in LOADING_STATES) return@collect;
+ // Skip initial idle state, since we are only interested when
+ // state becomes idle after not being idle
+ stopForegroundWhenNotOngoing = stateCount > 1 && it in BACKGROUNDABLE_STATES
+ removeNotificationWhenNotOngoing = stopForegroundWhenNotOngoing && it in REMOVABLE_STATES
+ }
+ }
+
  scope.launch {
  event.notificationStateChange.collect {
  when (it) {
  is NotificationState.POSTED -> {
  Timber.d("notification posted with id=%s, ongoing=%s", it.notificationId, it.ongoing)
  notificationId = it.notificationId;
  notification = it.notification;
- }
- else -> {}
- }
- }
- }
- scope.launch {
- event.stateChange.collect {
- when (it) {
- AudioPlayerState.BUFFERING,
- AudioPlayerState.PLAYING -> {
- startForegroundIfNecessary()
- }
- AudioPlayerState.IDLE,
- AudioPlayerState.STOPPED,
- AudioPlayerState.ERROR,
- AudioPlayerState.PAUSED -> {
- val removeNotification = it != AudioPlayerState.PAUSED && it != AudioPlayerState.ERROR
- if (removeNotification || isForegroundService()) {
- @Suppress("DEPRECATION")
- stopForeground(removeNotification)
- Timber.d("stopped foregrounding")
+ if (it.ongoing) {
+ if (player.playWhenReady) {
+ startForegroundIfNecessary()
+ }
+ } else if (stopForegroundWhenNotOngoing) {
+ if (removeNotificationWhenNotOngoing || isForegroundService()) {
+ @Suppress("DEPRECATION")
+ stopForeground(removeNotificationWhenNotOngoing)
+ Timber.d("stopped foregrounding%s", if (removeNotificationWhenNotOngoing) " and removed notification" else "")
+ }
  }
  }
  else -> {}