Added tracking/capturing/restoration of audio playback state and position.

Harmonia.WinUI/App.xaml.cs

@@ -58,7 +58,7 @@ public partial class App : Application
         await sessionService.LoadAsync();
 
         ISessionRestorer sessionRestorer = ServiceProvider.GetRequiredService<ISessionRestorer>();
-        sessionRestorer.Restore();
+        await sessionRestorer.RestoreAsync();
 
         ISessionTracker sessionTracker = ServiceProvider.GetRequiredService<ISessionTracker>();
         sessionTracker.Start();

Harmonia.WinUI/MainWindow.xaml.cs

@@ -9,12 +9,14 @@ public sealed partial class MainWindow : Window
     private const string ApplicationTitle = "Harmonia";
 
     private readonly ISessionService _sessionService;
+    private readonly ISessionTracker _sessionTracker;
 
     private bool _isSaved;
 
-    public MainWindow(ISessionService sessionService)
+    public MainWindow(ISessionService sessionService, ISessionTracker sessionTracker)
     {
         _sessionService = sessionService;
+        _sessionTracker = sessionTracker;
 
         InitializeComponent();
         InitializeTitleBar();
@@ -57,6 +59,7 @@ public sealed partial class MainWindow : Window
 
         args.Handled = true;
 
+        _sessionTracker.Capture();
         await _sessionService.SaveAsync();
 
         _isSaved = true;

Harmonia.WinUI/Session/AudioPlayerState.cs

@@ -1,11 +1,13 @@
-namespace Harmonia.WinUI.Session;
+using Harmonia.Core.Engine;
+
+namespace Harmonia.WinUI.Session;
 
 public partial class AudioPlayerState
 {
     public string? PlaylistUID { get; set; }
     public string? PlaylistSongUID { get; set; }
     public double Position { get; set; } = 0.0;
-    public string? PlaybackState { get; set; }
+    public AudioPlaybackState PlaybackState { get; set; } = AudioPlaybackState.Stopped;
     public double Volume { get; set; } = 1.0;
     public bool IsMuted { get; set; }
     public string? RepeatState { get; set; }

Harmonia.WinUI/Session/ISessionRestorer.cs

@@ -1,6 +1,8 @@
-namespace Harmonia.WinUI.Session;
+using System.Threading.Tasks;
+
+namespace Harmonia.WinUI.Session;
 
 public interface ISessionRestorer
 {
-    void Restore();
+    Task RestoreAsync();
 }

Harmonia.WinUI/Session/ISessionTracker.cs

@@ -3,4 +3,5 @@ namespace Harmonia.WinUI.Session;
 public interface ISessionTracker
 {
     void Start();
+    void Capture();
 }

Harmonia.WinUI/Session/SessionRestorer.cs

@@ -1,7 +1,9 @@
-using Harmonia.Core.Player;
+using Harmonia.Core.Engine;
+using Harmonia.Core.Player;
 using Harmonia.Core.Playlists;
 using System;
 using System.Linq;
+using System.Threading.Tasks;
 
 namespace Harmonia.WinUI.Session;
 
@@ -10,10 +12,10 @@ public class SessionRestorer(
     IPlaylistManager playlistManager,
     IAudioPlayer audioPlayer) : ISessionRestorer
 {
-    public void Restore()
+    public async Task RestoreAsync()
     {
         RestorePlaylist();
-        RestoreAudioPlayer();
+        await RestoreAudioPlayerAsync();
     }
 
     private void RestorePlaylist()
@@ -31,7 +33,7 @@ public class SessionRestorer(
         playlistManager.CurrentPlaylist = playlist;
     }
 
-    private void RestoreAudioPlayer()
+    private async Task RestoreAudioPlayerAsync()
     {
         AudioPlayerState audioPlayerState = sessionService.Session.Player;
 
@@ -43,13 +45,27 @@ public class SessionRestorer(
         if (playlist is null)
             return;
 
-        PlaylistSong? song = playlist.Songs.FirstOrDefault(s => s.UID == audioPlayerState.PlaylistSongUID);
+        PlaylistSong? playlistSong = playlist.Songs.FirstOrDefault(s => s.UID == audioPlayerState.PlaylistSongUID);
 
-        if (song is null)
+        if (playlistSong is null)
             return;
 
-        //PlaybackMode playbackMode = audioPlayerState.PlaybackState
+        await audioPlayer.LoadAsync(playlistSong, PlaybackMode.LoadOnly);
 
-        audioPlayer.LoadAsync(song, PlaybackMode.LoadOnly);
+        if (audioPlayerState.Position > 0 && audioPlayerState.Position <= playlistSong.Song.Length.TotalSeconds)
+            audioPlayer.Position = audioPlayerState.Position;
+
+        switch (audioPlayerState.PlaybackState)
+        {
+            case AudioPlaybackState.Playing:
+                audioPlayer.Play();
+                break;
+            case AudioPlaybackState.Paused:
+                audioPlayer.Pause();
+                break;
+            case AudioPlaybackState.Stopped:
+                audioPlayer.Stop();
+                break;
+        }
     }
 }

Harmonia.WinUI/Session/SessionTracker.cs

@@ -13,6 +13,7 @@ public class SessionTracker(
     {
         playlistManager.CurrentPlaylistChanged += OnCurrentPlaylistChanged;
         audioPlayer.PlayingSongChanged += OnPlayingSongChanged;
+        audioPlayer.PropertyChanged += OnAudioPlayerPropertyChanged;
     }
 
     private void OnCurrentPlaylistChanged(object? sender, EventArgs e)
@@ -26,4 +27,19 @@ public class SessionTracker(
         AudioPlayerState audioPlayerState = sessionService.Session.Player;
         audioPlayerState.PlaylistSongUID = e.NewSong?.UID;
     }
+
+    private void OnAudioPlayerPropertyChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
+    {
+        switch (e.PropertyName)
+        {
+            case nameof(IAudioPlayer.State):
+                sessionService.Session.Player.PlaybackState = audioPlayer.State;
+                break;
+        }
+    }
+
+    public void Capture()
+    {
+        sessionService.Session.Player.Position = audioPlayer.Position;
+    }
 }

Harmonia.WinUI/ViewModels/PlayerViewModel.cs

@@ -225,6 +225,20 @@ public partial class PlayerViewModel : ViewModelBase
         _timer.Tick += TickTock;
 
         _dispatcherQueue = DispatcherQueue.GetForCurrentThread();
+
+        TryRestore();
+    }
+
+    private void TryRestore()
+    {
+        if (_audioPlayer.PlayingSong is null)
+            return;
+
+        Song = _audioPlayer.PlayingSong.Song;
+        Position = _audioPlayer.Position;
+        CurrentPosition = _audioPlayer.Position;
+
+        Task.Run(UpdateImage);
     }
 
     #region Event Handlers

Harmonia.WinUI/ViewModels/PlayingSongViewModel.cs

@@ -50,6 +50,17 @@ public partial class PlayingSongViewModel : ViewModelBase
 
         _audioBitmapImageCache = audioBitmapImageCache;
         _dispatcherQueue = DispatcherQueue.GetForCurrentThread();
+
+        TryRestore();
+    }
+
+    private void TryRestore()
+    {
+        if (_audioPlayer.PlayingSong is null)
+            return;
+
+        Song = _audioPlayer.PlayingSong.Song;
+        Task.Run(UpdateImage);
     }
 
     private void OnAudioPlayerPlayingSongChanged(object? sender, PlayingSongChangedEventArgs e)

Harmonia.WinUI/ViewModels/PlaylistDetailViewModel.cs

@@ -220,6 +220,8 @@ public partial class PlaylistDetailViewModel : ViewModelBase
         FilteredPlaylistSongs.CollectionChanged += OnFilteredPlaylistSongsCollectionChanged;
 
         Playlist = _playlistManager.CurrentPlaylist; // Testing
+        PlayingSong = _audioPlayer.PlayingSong; // Testing
+
         UpdateFilteredSongs();
     }
 

Harmonia.WinUI/Views/PlaylistDetailView.xaml.cs

@@ -56,6 +56,16 @@ public sealed partial class PlaylistDetailView : UserControl
             SortSelectedByMenuFlyoutSubItem.IsEnabled = _viewModel.SortSelectedCommand.CanExecute(null);
 
         SortSelectedByMenuFlyoutSubItem.IsEnabled = _viewModel.SortSelectedCommand.CanExecute(null);
+
+        Loaded += OnLoaded;
+    }
+
+    private void OnLoaded(object sender, RoutedEventArgs e)
+    {
+        Loaded -= OnLoaded;
+
+        // Defer until the ListView has completed its first layout/container realization pass.
+        DispatcherQueue.TryEnqueue(DispatcherQueuePriority.Low, BringPlayingSongIntoView);
     }
 
     private void OnViewModelPropertyChanging(object? sender, PropertyChangingEventArgs e)
@@ -274,7 +284,7 @@ public sealed partial class PlaylistDetailView : UserControl
         if (args.NewValue is not PlaylistSong playlistSong)
             return;
 
-        bool isPlaying = playlistSong == _viewModel.PlayingSong;
+        bool isPlaying = playlistSong.UID == _viewModel.PlayingSong?.UID;
         
         UpdateListViewItemStyle(sender, isPlaying);
     }