Fix issues with PlaybackFragment seekbar

Fix bugs where PlaybackFragment's seekbar would update the player on the fly/flip out if PlaybackService updated the position while it was seeking.

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

@@ -134,7 +134,9 @@ class PlaybackFragment : Fragment(), SeekBar.OnSeekBarChangeListener {
         }
 
         playbackModel.positionAsProgress.observe(viewLifecycleOwner) {
-            binding.playbackSeekBar.progress = it
+            if (!playbackModel.isSeeking.value!!) {
+                binding.playbackSeekBar.progress = it
+            }
         }
 
         Log.d(this::class.simpleName, "Fragment Created.")
@@ -145,7 +147,7 @@ class PlaybackFragment : Fragment(), SeekBar.OnSeekBarChangeListener {
     // Seeking callbacks
     override fun onProgressChanged(seekBar: SeekBar, progress: Int, fromUser: Boolean) {
         if (fromUser) {
-            playbackModel.updatePositionWithProgress(progress)
+            playbackModel.updatePositionDisplay(progress)
         }
     }
 
@@ -155,5 +157,7 @@ class PlaybackFragment : Fragment(), SeekBar.OnSeekBarChangeListener {
 
     override fun onStopTrackingTouch(seekBar: SeekBar) {
         playbackModel.setSeekingStatus(false)
+
+        playbackModel.updatePosition(seekBar.progress)
     }
 }

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

@@ -22,6 +22,8 @@ import org.oxycblt.auxio.music.toURI
 import org.oxycblt.auxio.playback.state.PlaybackStateCallback
 import org.oxycblt.auxio.playback.state.PlaybackStateManager
 
+// A Service that manages the single ExoPlayer instance and [attempts] to keep
+// persistence if the app closes.
 class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
     private val player: SimpleExoPlayer by lazy {
         val p = SimpleExoPlayer.Builder(applicationContext).build()
@@ -54,8 +56,16 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
         super.onDestroy()
 
         player.release()
-        playbackManager.removeCallback(this)
         serviceJob.cancel()
+        playbackManager.removeCallback(this)
+    }
+
+    override fun onPlaybackStateChanged(state: Int) {
+        if (state == Player.STATE_ENDED) {
+            playbackManager.next()
+        } else if (state == Player.STATE_READY) {
+            startPollingPosition()
+        }
     }
 
     override fun onSongUpdate(song: Song?) {
@@ -100,14 +110,6 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateCallback {
         }
     }
 
-    override fun onPlaybackStateChanged(state: Int) {
-        if (state == Player.STATE_ENDED) {
-            playbackManager.skipNext()
-        } else if (state == Player.STATE_READY) {
-            startPollingPosition()
-        }
-    }
-
     inner class LocalBinder : Binder() {
         fun getService() = this@PlaybackService
     }

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

@@ -20,7 +20,10 @@ import org.oxycblt.auxio.playback.state.PlaybackMode
 import org.oxycblt.auxio.playback.state.PlaybackStateCallback
 import org.oxycblt.auxio.playback.state.PlaybackStateManager
 
-// The UI frontend for PlaybackStateManager.
+// A ViewModel that acts as an intermediary between the UI and PlaybackStateManager
+// TODO: Implement Looping Modes
+// TODO: Implement User Queue
+// TODO: Implement Persistence through Bundles/Databases/Idk
 class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackStateCallback {
     // Playback
     private val mSong = MutableLiveData<Song>()
@@ -88,14 +91,17 @@ class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackSta
 
     // --- PLAYING FUNCTIONS ---
 
+    // Play a song
     fun playSong(song: Song, mode: PlaybackMode) {
         playbackManager.playSong(song, mode)
     }
 
+    // Play all songs
     fun shuffleAll() {
         playbackManager.shuffleAll()
     }
 
+    // Play an album
     fun playAlbum(album: Album, shuffled: Boolean) {
         if (album.songs.isEmpty()) {
             Log.e(this::class.simpleName, "Album is empty, Not playing.")
@@ -106,6 +112,7 @@ class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackSta
         playbackManager.playParentModel(album, shuffled)
     }
 
+    // Play an artist
     fun playArtist(artist: Artist, shuffled: Boolean) {
         if (artist.songs.isEmpty()) {
             Log.e(this::class.simpleName, "Artist is empty, Not playing.")
@@ -116,6 +123,7 @@ class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackSta
         playbackManager.playParentModel(artist, shuffled)
     }
 
+    // Play a genre
     fun playGenre(genre: Genre, shuffled: Boolean) {
         if (genre.songs.isEmpty()) {
             Log.e(this::class.simpleName, "Genre is empty, Not playing.")
@@ -128,7 +136,15 @@ class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackSta
 
     // --- POSITION FUNCTIONS ---
 
-    fun updatePositionWithProgress(progress: Int) {
+    // Update the position without pushing the change to playbackManager.
+    // This is used during seek events to give the user an idea of where they're seeking to.
+    fun updatePositionDisplay(progress: Int) {
+        mPosition.value = progress.toLong()
+    }
+
+    // Update the position and push the change the playbackManager.
+    // This is done when the seek is confirmed to make playbackService seek to the position.
+    fun updatePosition(progress: Int) {
         playbackManager.setPosition(progress.toLong())
 
         playbackService.doSeek(progress.toLong())
@@ -136,14 +152,17 @@ class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackSta
 
     // --- QUEUE FUNCTIONS ---
 
+    // Skip to next song.
     fun skipNext() {
-        playbackManager.skipNext()
+        playbackManager.next()
     }
 
+    // Skip to last song.
     fun skipPrev() {
-        playbackManager.skipPrev()
+        playbackManager.prev()
     }
 
+    // Remove a queue item, given a QueueAdapter index.
     fun removeQueueItem(adapterIndex: Int) {
         // Translate the adapter indices into the correct queue indices
         val delta = mQueue.value!!.size - nextItemsInQueue.value!!.size
@@ -153,6 +172,7 @@ class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackSta
         playbackManager.removeQueueItem(index)
     }
 
+    // Move queue items, given QueueAdapter indices.
     fun moveQueueItems(adapterFrom: Int, adapterTo: Int) {
         // Translate the adapter indices into the correct queue indices
         val delta = mQueue.value!!.size - nextItemsInQueue.value!!.size
@@ -165,12 +185,14 @@ class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackSta
 
     // --- STATUS FUNCTIONS ---
 
+    // Flip the playing status.
     fun invertPlayingStatus() {
         mCanAnimate = true
 
         playbackManager.setPlayingStatus(!playbackManager.isPlaying)
     }
 
+    // Flip the shuffle status.
     fun invertShuffleStatus() {
         playbackManager.setShuffleStatus(!playbackManager.isShuffling)
     }
@@ -198,7 +220,9 @@ class PlaybackViewModel(private val context: Context) : ViewModel(), PlaybackSta
     }
 
     override fun onPositionUpdate(position: Long) {
-        mPosition.value = position
+        if (!mIsSeeking.value!!) {
+            mPosition.value = position
+        }
     }
 
     override fun onQueueUpdate(queue: MutableList<Song>) {

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

@@ -166,7 +166,7 @@ class PlaybackStateManager {
 
     // --- QUEUE FUNCTIONS ---
 
-    fun skipNext() {
+    fun next() {
         if (mIndex < mQueue.size) {
             mIndex = mIndex.inc()
         }
@@ -176,7 +176,7 @@ class PlaybackStateManager {
         forceQueueUpdate()
     }
 
-    fun skipPrev() {
+    fun prev() {
         if (mIndex > 0) {
             mIndex = mIndex.dec()
         }
@@ -215,6 +215,7 @@ class PlaybackStateManager {
         forceQueueUpdate()
     }
 
+    // Force any callbacks to update when the queue is changed.
     private fun forceQueueUpdate() {
         mQueue = mQueue
     }