Allow media session resuming from media buttons when service is killed.

app/src/main/AndroidManifest.xml

@@ -34,15 +34,22 @@
       android:name="com.github.apognu.otter.activities.LoginActivity"
       android:configChanges="screenSize|orientation"
       android:launchMode="singleInstance" />
+
     <activity android:name="com.github.apognu.otter.activities.MainActivity" />
+
     <activity
       android:name="com.github.apognu.otter.activities.SearchActivity"
       android:launchMode="singleTop" />
+
     <activity android:name="com.github.apognu.otter.activities.DownloadsActivity" />
+
     <activity android:name="com.github.apognu.otter.activities.SettingsActivity" />
+
     <activity android:name="com.github.apognu.otter.activities.LicencesActivity" />
 
-    <service android:name="com.github.apognu.otter.playback.PlayerService" android:foregroundServiceType="mediaPlayback" />
+    <service
+      android:name="com.github.apognu.otter.playback.PlayerService"
+      android:foregroundServiceType="mediaPlayback" />
 
     <service
       android:name=".playback.PinService"

app/src/main/java/com/github/apognu/otter/Otter.kt

@@ -1,9 +1,8 @@
 package com.github.apognu.otter
 
 import android.app.Application
-import android.support.v4.media.session.MediaSessionCompat
-import android.support.v4.media.session.PlaybackStateCompat
 import androidx.appcompat.app.AppCompatDelegate
+import com.github.apognu.otter.playback.MediaSession
 import com.github.apognu.otter.playback.QueueManager
 import com.github.apognu.otter.utils.*
 import com.google.android.exoplayer2.database.ExoDatabaseProvider
@@ -62,25 +61,7 @@ class Otter : Application() {
     }
   }
 
-  private val playbackStateBuilder = PlaybackStateCompat.Builder().apply {
-    setActions(
-      PlaybackStateCompat.ACTION_PLAY_PAUSE or
-        PlaybackStateCompat.ACTION_PLAY or
-        PlaybackStateCompat.ACTION_PAUSE or
-        PlaybackStateCompat.ACTION_SKIP_TO_NEXT or
-        PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS or
-        PlaybackStateCompat.ACTION_SEEK_TO or
-        PlaybackStateCompat.ACTION_SKIP_TO_QUEUE_ITEM
-    )
-  }
-
-  val mediaSession: MediaSessionCompat by lazy {
-    MediaSessionCompat(this, applicationContext.packageName).apply {
-      setFlags(MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS or MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS)
-      setPlaybackState(playbackStateBuilder.build())
-      isActive = true
-    }
-  }
+  val mediaSession = MediaSession(this)
 
   override fun onCreate() {
     super.onCreate()

app/src/main/java/com/github/apognu/otter/activities/MainActivity.kt

@@ -6,6 +6,7 @@ import android.animation.ObjectAnimator
 import android.annotation.SuppressLint
 import android.content.Intent
 import android.graphics.Bitmap
+import android.os.Build
 import android.os.Bundle
 import android.util.DisplayMetrics
 import android.view.*
@@ -43,7 +44,6 @@ import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.coroutines.Dispatchers.Main
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.toList
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 
@@ -291,9 +291,18 @@ class MainActivity : AppCompatActivity() {
       CommandBus.get().collect { command ->
         when (command) {
           is Command.StartService -> {
-            startService(Intent(this@MainActivity, PlayerService::class.java).apply {
-              putExtra(PlayerService.INITIAL_COMMAND_KEY, command.command.toString())
-            })
+            Build.VERSION_CODES.O.onApi(
+              {
+                startForegroundService(Intent(this@MainActivity, PlayerService::class.java).apply {
+                  putExtra(PlayerService.INITIAL_COMMAND_KEY, command.command.toString())
+                })
+              },
+              {
+                startService(Intent(this@MainActivity, PlayerService::class.java).apply {
+                  putExtra(PlayerService.INITIAL_COMMAND_KEY, command.command.toString())
+                })
+              }
+            )
           }
 
           is Command.RefreshTrack -> refreshCurrentTrack(command.track)

app/src/main/java/com/github/apognu/otter/playback/MediaSession.kt

@@ -0,0 +1,103 @@
+package com.github.apognu.otter.playback
+
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import android.os.ResultReceiver
+import android.support.v4.media.session.MediaSessionCompat
+import android.support.v4.media.session.PlaybackStateCompat
+import android.view.KeyEvent
+import com.github.apognu.otter.Otter
+import com.github.apognu.otter.utils.Command
+import com.github.apognu.otter.utils.CommandBus
+import com.google.android.exoplayer2.ControlDispatcher
+import com.google.android.exoplayer2.Player
+import com.google.android.exoplayer2.ext.mediasession.MediaSessionConnector
+
+class MediaSession(private val context: Context) {
+  var active: Boolean = false
+
+  private val playbackStateBuilder = PlaybackStateCompat.Builder().apply {
+    setActions(
+      PlaybackStateCompat.ACTION_PLAY_PAUSE or
+        PlaybackStateCompat.ACTION_PLAY or
+        PlaybackStateCompat.ACTION_PAUSE or
+        PlaybackStateCompat.ACTION_SKIP_TO_NEXT or
+        PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS or
+        PlaybackStateCompat.ACTION_SEEK_TO or
+        PlaybackStateCompat.ACTION_SKIP_TO_QUEUE_ITEM
+    )
+  }
+
+  val session: MediaSessionCompat by lazy {
+    active = true
+
+    MediaSessionCompat(context, context.packageName).apply {
+      setFlags(MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS or MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS)
+      setPlaybackState(playbackStateBuilder.build())
+
+      isActive = true
+    }
+  }
+
+  val connector: MediaSessionConnector by lazy {
+    MediaSessionConnector(Otter.get().mediaSession.session).also {
+      it.setQueueNavigator(OtterQueueNavigator())
+
+      it.setMediaButtonEventHandler { _, _, event ->
+        if (!active) {
+          event.extras?.getParcelable<KeyEvent>(Intent.EXTRA_KEY_EVENT)?.let { key ->
+            if (key.action == KeyEvent.ACTION_UP) {
+              val command = when (key.keyCode) {
+                KeyEvent.KEYCODE_MEDIA_PLAY -> Command.ToggleState
+                KeyEvent.KEYCODE_MEDIA_PAUSE -> Command.ToggleState
+                KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE -> Command.ToggleState
+                KeyEvent.KEYCODE_MEDIA_NEXT -> Command.NextTrack
+                KeyEvent.KEYCODE_MEDIA_PREVIOUS -> Command.PreviousTrack
+                else -> null
+              }
+
+              command?.let {
+                CommandBus.send(command)
+                CommandBus.send(Command.StartService(command))
+
+                return@setMediaButtonEventHandler true
+              }
+            }
+          }
+        }
+
+        false
+      }
+    }
+  }
+}
+
+class OtterQueueNavigator : MediaSessionConnector.QueueNavigator {
+  override fun onSkipToQueueItem(player: Player, controlDispatcher: ControlDispatcher, id: Long) {
+    CommandBus.send(Command.PlayTrack(id.toInt()))
+  }
+
+  override fun onCurrentWindowIndexChanged(player: Player) {}
+
+  override fun onCommand(player: Player, controlDispatcher: ControlDispatcher, command: String, extras: Bundle?, cb: ResultReceiver?) = true
+
+  override fun getSupportedQueueNavigatorActions(player: Player): Long {
+    return PlaybackStateCompat.ACTION_PLAY_PAUSE or
+      PlaybackStateCompat.ACTION_SKIP_TO_NEXT or
+      PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS or
+      PlaybackStateCompat.ACTION_SKIP_TO_QUEUE_ITEM
+  }
+
+  override fun onSkipToNext(player: Player, controlDispatcher: ControlDispatcher) {
+    CommandBus.send(Command.NextTrack)
+  }
+
+  override fun getActiveQueueItemId(player: Player?) = 0L
+
+  override fun onSkipToPrevious(player: Player, controlDispatcher: ControlDispatcher) {
+    CommandBus.send(Command.PreviousTrack)
+  }
+
+  override fun onTimelineChanged(player: Player) {}
+}

app/src/main/java/com/github/apognu/otter/playback/PlayerService.kt

@@ -10,17 +10,15 @@ import android.media.AudioFocusRequest
 import android.media.AudioManager
 import android.media.MediaMetadata
 import android.os.Build
-import android.os.Bundle
 import android.os.IBinder
-import android.os.ResultReceiver
 import android.support.v4.media.MediaMetadataCompat
-import android.support.v4.media.session.PlaybackStateCompat
-import android.view.KeyEvent
 import com.github.apognu.otter.Otter
 import com.github.apognu.otter.R
 import com.github.apognu.otter.utils.*
-import com.google.android.exoplayer2.*
-import com.google.android.exoplayer2.ext.mediasession.MediaSessionConnector
+import com.google.android.exoplayer2.C
+import com.google.android.exoplayer2.ExoPlaybackException
+import com.google.android.exoplayer2.Player
+import com.google.android.exoplayer2.SimpleExoPlayer
 import com.google.android.exoplayer2.source.TrackGroupArray
 import com.google.android.exoplayer2.trackselection.TrackSelectionArray
 import com.squareup.picasso.Picasso
@@ -61,6 +59,8 @@ class PlayerService : Service() {
 
       intent?.extras?.getString(INITIAL_COMMAND_KEY)?.let {
         when (it) {
+          Command.SetState(true).toString() -> setPlaybackState(true)
+          Command.SetState(false).toString() -> setPlaybackState(false)
           Command.ToggleState.toString() -> togglePlayback()
           Command.NextTrack.toString() -> skipToNextTrack()
           Command.PreviousTrack.toString() -> skipToPreviousTrack()
@@ -97,7 +97,7 @@ class PlayerService : Service() {
       }
     }
 
-    mediaControlsManager = MediaControlsManager(this, scope, Otter.get().mediaSession)
+    mediaControlsManager = MediaControlsManager(this, scope, Otter.get().mediaSession.session)
 
     player = SimpleExoPlayer.Builder(this).build().apply {
       playWhenReady = false
@@ -105,28 +105,13 @@ class PlayerService : Service() {
       playerEventListener = PlayerEventListener().also {
         addListener(it)
       }
+    }
 
-      MediaSessionConnector(Otter.get().mediaSession).also {
-        it.setPlayer(this)
-        it.setQueueNavigator(OtterQueueNavigator())
-        it.setMediaMetadataProvider {
-          buildTrackMetadata(queue.current())
-        }
-
-        it.setMediaButtonEventHandler { player, _, mediaButtonEvent ->
-          mediaButtonEvent.extras?.getParcelable<KeyEvent>(Intent.EXTRA_KEY_EVENT)?.let { key ->
-            if (key.action == KeyEvent.ACTION_UP) {
-              when (key.keyCode) {
-                KeyEvent.KEYCODE_MEDIA_PLAY -> setPlaybackState(true)
-                KeyEvent.KEYCODE_MEDIA_PAUSE -> setPlaybackState(false)
-                KeyEvent.KEYCODE_MEDIA_NEXT -> player.next()
-                KeyEvent.KEYCODE_MEDIA_PREVIOUS -> skipToPreviousTrack()
-              }
-            }
-          }
+    Otter.get().mediaSession.connector.apply {
+      setPlayer(player)
 
-          true
-        }
+      setMediaMetadataProvider {
+        buildTrackMetadata(queue.current())
       }
     }
 
@@ -250,6 +235,8 @@ class PlayerService : Service() {
         audioManager.abandonAudioFocus(audioFocusChangeListener)
       })
 
+    Otter.get().mediaSession.active = false
+
     player.removeListener(playerEventListener)
     setPlaybackState(false)
     player.release()
@@ -470,33 +457,4 @@ class PlayerService : Service() {
       }
     }
   }
-
-  inner class OtterQueueNavigator : MediaSessionConnector.QueueNavigator {
-    override fun onSkipToQueueItem(player: Player, controlDispatcher: ControlDispatcher, id: Long) {
-      CommandBus.send(Command.PlayTrack(id.toInt()))
-    }
-
-    override fun onCurrentWindowIndexChanged(player: Player) {}
-
-    override fun onCommand(player: Player, controlDispatcher: ControlDispatcher, command: String, extras: Bundle?, cb: ResultReceiver?) = true
-
-    override fun getSupportedQueueNavigatorActions(player: Player): Long {
-      return PlaybackStateCompat.ACTION_PLAY_PAUSE or
-        PlaybackStateCompat.ACTION_SKIP_TO_NEXT or
-        PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS or
-        PlaybackStateCompat.ACTION_SKIP_TO_QUEUE_ITEM
-    }
-
-    override fun onSkipToNext(player: Player, controlDispatcher: ControlDispatcher) {
-      skipToNextTrack()
-    }
-
-    override fun getActiveQueueItemId(player: Player?) = queue.current.toLong()
-
-    override fun onSkipToPrevious(player: Player, controlDispatcher: ControlDispatcher) {
-      skipToPreviousTrack()
-    }
-
-    override fun onTimelineChanged(player: Player) {}
-  }
 }