Highlight active playlist. Various optimizations and fixes.

Harmonia.Core/Player/AudioPlayer.cs

@@ -173,7 +173,7 @@ public class AudioPlayer : IAudioPlayer
             return;
         }
 
-        int currentIndex = Playlist.Songs.IndexOf(CurrentPlaylistSong);
+        int currentIndex = Playlist.IndexOf(CurrentPlaylistSong);
         int nextIndex = currentIndex + 1;
 
         if (nextIndex > Playlist.Songs.Count - 1)
@@ -200,7 +200,7 @@ public class AudioPlayer : IAudioPlayer
             return;
         }
 
-        int currentIndex = Playlist.Songs.IndexOf(CurrentPlaylistSong);
+        int currentIndex = Playlist.IndexOf(CurrentPlaylistSong);
         int nextIndex = currentIndex - 1;
 
         if (nextIndex < 0)
@@ -233,7 +233,7 @@ public class AudioPlayer : IAudioPlayer
     {
         if (Playlist == null || Playlist.Songs.Contains(song) == false)
         {
-            Playlist? newPlaylist = _playlistManager.GetPlaylist(song);
+            Playlist? newPlaylist = _playlistManager.FindPlaylistContaining(song);
 
             if (newPlaylist == null)
                 return false;

Harmonia.Core/Playlists/IPlaylistManager.cs

@@ -8,7 +8,7 @@ public interface IPlaylistManager
     Task InitializeAsync();
     Task<Playlist> AddPlaylistAsync();
     void RemovePlaylist(Playlist playlist);
-    Playlist? GetPlaylist(PlaylistSong playlistSong);
+    Playlist? FindPlaylistContaining(PlaylistSong playlistSong);
 
     event EventHandler? CurrentPlaylistChanged;
     event EventHandler<PlaylistAddedEventArgs> PlaylistAdded;

Harmonia.Core/Playlists/IPlaylistRepository.cs

@@ -4,10 +4,5 @@ namespace Harmonia.Core.Playlists;
 
 public interface IPlaylistRepository : IRepository<Playlist>
 {
-    Playlist? GetPlaylist(PlaylistSong playlistSong);
-    //void AddPlaylist();
-    //void RemovePlaylist(Playlist playlist);
 
-    //event EventHandler<PlaylistAddedEventArgs> PlaylistAdded;
-    //event EventHandler<PlaylistRemovedEventArgs> PlaylistRemoved;
 }

Harmonia.Core/Playlists/Playlist.cs

@@ -5,15 +5,48 @@ namespace Harmonia.Core.Playlists;
 
 public class Playlist
 {
+    private readonly List<PlaylistSong> _songs = [];
+    private readonly List<GroupOption> _groupOptions = [];
+    private readonly List<SortOption> _sortOptions = [];
+
     public string UID { get; init; } = Guid.NewGuid().ToString();
-    public string? Name { get; set; }
+    public string? Name { get; private set; }
-    public List<PlaylistSong> Songs { get; init; } = []; // TODO: Change to "private init" once deserialization is fixed
+    public IReadOnlyList<PlaylistSong> Songs => _songs;
-    public List<GroupOption> GroupOptions { get; set; } = [];
+    public IReadOnlyList<GroupOption> GroupOptions => _groupOptions;
-    public List<SortOption> SortOptions { get; set; } = [];
+    public IReadOnlyList<SortOption> SortOptions => _sortOptions;
-    public bool IsLocked { get; set; }
+    public bool IsLocked { get; private set; }
 
     public event EventHandler<PlaylistUpdatedEventArgs>? PlaylistUpdated;
 
+    public Playlist()
+    {
+    }
+
+    public Playlist(string? name)
+    {
+        Name = name;
+    }
+
+    internal static Playlist Restore(string uid, string? name, IEnumerable<PlaylistSong> songs, IEnumerable<GroupOption> groupOptions, IEnumerable<SortOption> sortOptions, bool isLocked)
+    {
+        Playlist playlist = new(name)
+        {
+            UID = uid,
+            IsLocked = isLocked
+        };
+
+        playlist._songs.AddRange(songs);
+        playlist._groupOptions.AddRange(groupOptions);
+        playlist._sortOptions.AddRange(sortOptions);
+
+        return playlist;
+    }
+
+    public int IndexOf(PlaylistSong playlistSong)
+    {
+        return _songs.IndexOf(playlistSong);
+    }
+
     public void SetName(string name)
     {
         if (string.Equals(Name, name, StringComparison.Ordinal))
@@ -88,9 +121,9 @@ public class Playlist
         if (playlistSongs.Length == 0)
             return;
 
-        int insertIndex = index ?? Songs.Count;
+        int insertIndex = index ?? _songs.Count;
 
-        Songs.InsertRange(insertIndex, playlistSongs);
+        _songs.InsertRange(insertIndex, playlistSongs);
 
         PlaylistUpdatedEventArgs eventArgs = new()
         {
@@ -105,7 +138,7 @@ public class Playlist
 
     public void MoveSong(PlaylistSong playlistSong, int newIndex)
     {
-        int currentIndex = Songs.IndexOf(playlistSong);
+        int currentIndex = _songs.IndexOf(playlistSong);
 
         MoveSong(currentIndex, newIndex);
     }
@@ -118,10 +151,10 @@ public class Playlist
         if (oldIndex == newIndex)
             return;
 
-        PlaylistSong playlistSong = Songs[oldIndex];
+        PlaylistSong playlistSong = _songs[oldIndex];
 
-        Songs.Remove(playlistSong);
+        _songs.Remove(playlistSong);
-        Songs.Insert(newIndex, playlistSong);
+        _songs.Insert(newIndex, playlistSong);
 
         PlaylistUpdatedEventArgs eventArgs = new()
         {
@@ -141,8 +174,8 @@ public class Playlist
             return;
 
         Dictionary<int, PlaylistSong> oldPlaylistSongs = playlistSongs
-            .OrderBy(Songs.IndexOf)
+            .OrderBy(_songs.IndexOf)
-            .ToDictionary(Songs.IndexOf, playlistSong => playlistSong);
+            .ToDictionary(_songs.IndexOf, playlistSong => playlistSong);
 
         Song[] songs = [.. playlistSongs.Select(playlistSong => playlistSong.Song)];
         Song[] sortedSongs = [.. songs.SortBy(sortOptions)];
@@ -158,8 +191,8 @@ public class Playlist
             if (newPlaylistSong == playlistSong)
                 continue;
 
-            Songs.RemoveAt(index);
+            _songs.RemoveAt(index);
-            Songs.Insert(index, newPlaylistSong);
+            _songs.Insert(index, newPlaylistSong);
         }
 
         PlaylistUpdatedEventArgs eventArgs = new()
@@ -178,11 +211,11 @@ public class Playlist
         if (IsLocked)
             return;
 
-        int[] originalIndexes = [.. playlistSongs.Select(playlistSong => Songs.IndexOf(playlistSong))];
+        int[] originalIndexes = [.. playlistSongs.Select(playlistSong => _songs.IndexOf(playlistSong))];
         PlaylistSong[] shuffledSongs = [.. playlistSongs.Shuffle()];
 
         for (int i = 0; i < originalIndexes.Length; i++)
-            Songs[originalIndexes[i]] = shuffledSongs[i];
+            _songs[originalIndexes[i]] = shuffledSongs[i];
 
         PlaylistUpdatedEventArgs eventArgs = new()
         {
@@ -200,11 +233,11 @@ public class Playlist
         if (IsLocked)
             return;
 
-        int[] originalIndexes = [.. playlistSongs.Select(playlistSong => Songs.IndexOf(playlistSong))];
+        int[] originalIndexes = [.. playlistSongs.Select(playlistSong => _songs.IndexOf(playlistSong))];
-        PlaylistSong[] reversedSongs = [.. originalIndexes.Select(i => Songs[i]).Reverse()];
+        PlaylistSong[] reversedSongs = [.. originalIndexes.Select(i => _songs[i]).Reverse()];
 
         for (int i = 0; i < originalIndexes.Length; i++)
-            Songs[originalIndexes[i]] = reversedSongs[i];
+            _songs[originalIndexes[i]] = reversedSongs[i];
 
         PlaylistUpdatedEventArgs eventArgs = new()
         {
@@ -224,7 +257,7 @@ public class Playlist
 
     public void RemoveSongs(int index, int count)
     {
-        PlaylistSong[] playlistSongs = [.. Songs.GetRange(index, count)];
+        PlaylistSong[] playlistSongs = [.. _songs.GetRange(index, count)];
 
         RemoveSongs(playlistSongs);
     }
@@ -243,7 +276,7 @@ public class Playlist
 
         foreach (PlaylistSong playlistSong in playlistSongs)
         {
-            if (Songs.Remove(playlistSong))
+            if (_songs.Remove(playlistSong))
             {
                 removedSongs.Add(playlistSong);
             }

Harmonia.Core/Playlists/PlaylistDto.cs

@@ -0,0 +1,60 @@
+using Harmonia.Core.Models;
+
+namespace Harmonia.Core.Playlists;
+
+internal sealed record PlaylistDto
+{
+    public string UID { get; init; } = Guid.NewGuid().ToString();
+    public string? Name { get; init; }
+    public List<PlaylistSongDto> Songs { get; init; } = [];
+    public List<GroupOption> GroupOptions { get; init; } = [];
+    public List<SortOption> SortOptions { get; init; } = [];
+    public bool IsLocked { get; init; }
+
+    public static PlaylistDto FromPlaylist(Playlist playlist)
+    {
+        return new PlaylistDto
+        {
+            UID = playlist.UID,
+            Name = playlist.Name,
+            Songs = [.. playlist.Songs.Select(PlaylistSongDto.FromPlaylistSong)],
+            GroupOptions = [.. playlist.GroupOptions],
+            SortOptions = [.. playlist.SortOptions],
+            IsLocked = playlist.IsLocked
+        };
+    }
+
+    public Playlist ToPlaylist()
+    {
+        return Playlist.Restore(
+            UID,
+            Name,
+            Songs.Select(song => song.ToPlaylistSong()),
+            GroupOptions,
+            SortOptions,
+            IsLocked);
+    }
+}
+
+internal sealed record PlaylistSongDto
+{
+    public string UID { get; init; } = Guid.NewGuid().ToString();
+    public required Song Song { get; init; }
+
+    public static PlaylistSongDto FromPlaylistSong(PlaylistSong playlistSong)
+    {
+        return new PlaylistSongDto
+        {
+            UID = playlistSong.UID,
+            Song = playlistSong.Song
+        };
+    }
+
+    public PlaylistSong ToPlaylistSong()
+    {
+        return new PlaylistSong(Song)
+        {
+            UID = UID
+        };
+    }
+}

Harmonia.Core/Playlists/PlaylistManager.cs

@@ -4,6 +4,7 @@ public class PlaylistManager : IPlaylistManager
 {
     private readonly IPlaylistRepository playlistRepository;
     private readonly List<Playlist> _playlists = [];
+    private readonly Dictionary<string, Playlist> _playlistsBySongUid = [];
 
     public IReadOnlyList<Playlist> Playlists => _playlists;
 
@@ -37,6 +38,11 @@ public class PlaylistManager : IPlaylistManager
         foreach (Playlist playlist in _playlists)
         {
             playlist.PlaylistUpdated += OnPlaylistUpdated;
+
+            foreach (PlaylistSong song in playlist.Songs)
+            {
+                _playlistsBySongUid[song.UID] = playlist;
+            }
         }
 
         CurrentPlaylist = _playlists.Count > 0 ? _playlists[0] : await AddPlaylistAsync();
@@ -44,14 +50,16 @@ public class PlaylistManager : IPlaylistManager
 
     public async Task<Playlist> AddPlaylistAsync()
     {
-        Playlist playlist = new()
+        Playlist playlist = new("New Playlist");
-        {
-            Name = "New Playlist"
-        };
 
         playlist.PlaylistUpdated += OnPlaylistUpdated;
         _playlists.Add(playlist);
 
+        foreach (PlaylistSong song in playlist.Songs)
+        {
+            _playlistsBySongUid[song.UID] = playlist;
+        }
+
         await playlistRepository.SaveAsync(playlist);
 
         PlaylistAdded?.Invoke(this, new(playlist));
@@ -64,14 +72,19 @@ public class PlaylistManager : IPlaylistManager
         playlist.PlaylistUpdated -= OnPlaylistUpdated;
         _playlists.Remove(playlist);
 
+        foreach (PlaylistSong song in playlist.Songs)
+        {
+            _playlistsBySongUid.Remove(song.UID);
+        }
+
         playlistRepository.Delete(playlist);
 
         PlaylistRemoved?.Invoke(this, new(playlist));
     }
 
-    public Playlist? GetPlaylist(PlaylistSong playlistSong)
+    public Playlist? FindPlaylistContaining(PlaylistSong playlistSong)
     {
-        return _playlists.FirstOrDefault(playlist => playlist.Songs.Any(song => song.UID == playlistSong.UID));
+        return _playlistsBySongUid.GetValueOrDefault(playlistSong.UID);
     }
 
     private async void OnPlaylistUpdated(object? sender, PlaylistUpdatedEventArgs e)
@@ -79,6 +92,22 @@ public class PlaylistManager : IPlaylistManager
         if (sender is not Playlist playlist)
             return;
 
+        switch (e.Action)
+        {
+            case PlaylistUpdateAction.Add:
+                foreach (PlaylistSong song in e.Songs)
+                {
+                    _playlistsBySongUid[song.UID] = playlist;
+                }
+                break;
+            case PlaylistUpdateAction.Remove:
+                foreach (PlaylistSong song in e.Songs)
+                {
+                    _playlistsBySongUid.Remove(song.UID);
+                }
+                break;
+        }
+
         await playlistRepository.SaveAsync(playlist);
     }
 }

Harmonia.Core/Playlists/PlaylistRepository.cs

@@ -1,14 +1,32 @@
 using Harmonia.Core.Data;
+using System.Text.Json;
+using System.Text.Json.Serialization;
 
 namespace Harmonia.Core.Playlists;
 
 public class PlaylistRepository : JsonFileRepository<Playlist>, IPlaylistRepository
 {
+    private static readonly JsonSerializerOptions _options = new()
+    {
+        WriteIndented = true,
+        IgnoreReadOnlyProperties = true,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
+    };
+
     protected override string DirectoryName => Path.Combine("Playlists");
 
-    public Playlist? GetPlaylist(PlaylistSong playlistSong)
+    protected override async Task<Playlist> DeserializeAsync(Stream stream)
     {
-        return Get().FirstOrDefault(playlist => playlist.Songs.Contains(playlistSong));
+        PlaylistDto dto = await JsonSerializer.DeserializeAsync<PlaylistDto>(stream, _options) ?? new();
+
+        return dto.ToPlaylist();
+    }
+
+    protected override Task<string> SerializeAsync(Playlist playlist)
+    {
+        PlaylistDto dto = PlaylistDto.FromPlaylist(playlist);
+
+        return Task.FromResult(JsonSerializer.Serialize(dto, _options));
     }
 
     protected override string GetNewFileName()

Harmonia.Tests/AudioPlayerTests.cs

@@ -21,7 +21,7 @@ internal class TestAudioPlayer(IAudioEngine audioEngine, IPlaylistManager playli
         if (Playlist == null || PlayingSong == null)
             return -1;
 
-        return Playlist.Songs.IndexOf(PlayingSong);
+        return Playlist.IndexOf(PlayingSong);
     }
 }
 
@@ -54,10 +54,7 @@ public class AudioPlayerTests
             new Song() { FileName = "Song7.mp3" }
         ];
 
-        Playlist playlist = new()
+        Playlist playlist = new("Playlist1");
-        {
-            Name = "Playlist1"
-        };
 
         playlist.AddSongs(songs);
 
@@ -65,7 +62,7 @@ public class AudioPlayerTests
 
         _playlistManager = Substitute.For<IPlaylistManager>();
         _playlistManager.Playlists.Returns([playlist]);
-        _playlistManager.GetPlaylist(Arg.Any<PlaylistSong>()).Returns(playlist);
+        _playlistManager.FindPlaylistContaining(Arg.Any<PlaylistSong>()).Returns(playlist);
 
         _audioPlayer = new TestAudioPlayer(_audioEngine, _playlistManager);
         _audioPlayer.SetPlaylist(playlist);

Harmonia.Tests/PlaylistTests.cs

@@ -114,7 +114,7 @@ public class PlaylistTests
 
         playlist.AddSongs(songs);
 
-        playlist.IsLocked = true;
+        playlist.Lock();
 
         Song song = new() { FileName = "Song4.mp3" };
         playlist.AddSong(song);

Harmonia.UI/ViewModels/PlaylistViewModel.cs

@@ -433,7 +433,7 @@ public class PlaylistViewModel : ViewModelBase
         if (Playlist == null || SelectedPlaylistSongs.Count == 0)
             return;
 
-        int selectedPlaylistSongIndex = Playlist.Songs.IndexOf(SelectedPlaylistSongs[0]);
+        int selectedPlaylistSongIndex = Playlist.IndexOf(SelectedPlaylistSongs[0]);
 
         if (selectedPlaylistSongIndex == -1)
             return;

Harmonia.WinUI/ViewModels/PlaylistDetailViewModel.cs

@@ -611,7 +611,7 @@ public partial class PlaylistDetailViewModel : ViewModelBase
         if (Playlist == null || SelectedPlaylistSongs.Count == 0)
             return;
 
-        int selectedPlaylistSongIndex = Playlist.Songs.IndexOf(SelectedPlaylistSongs[0]);
+        int selectedPlaylistSongIndex = Playlist.IndexOf(SelectedPlaylistSongs[0]);
 
         if (selectedPlaylistSongIndex == -1)
             return;

Harmonia.WinUI/ViewModels/PlaylistsViewModel.cs

@@ -1,4 +1,4 @@
-using CommunityToolkit.Mvvm.ComponentModel;
+using Harmonia.Core.Player;
 using Harmonia.Core.Playlists;
 using System;
 using System.Collections.ObjectModel;
@@ -9,6 +9,7 @@ namespace Harmonia.WinUI.ViewModels;
 public partial class PlaylistsViewModel : ViewModelBase
 {
     private readonly IPlaylistManager _playlistManager;
+    private readonly IAudioPlayer _audioPlayer;
 
     private ObservableCollection<PlaylistItemViewModel> _playlists = [];
     public ObservableCollection<PlaylistItemViewModel> Playlists
@@ -39,13 +40,29 @@ public partial class PlaylistsViewModel : ViewModelBase
         }
     }
 
-    public PlaylistsViewModel(IPlaylistManager playlistManager)
+    private PlaylistItemViewModel? _activePlaylist = null;
+    public PlaylistItemViewModel? ActivePlaylist
+    {
+        get
+        {
+            return _activePlaylist;
+        }
+        set
+        {
+            SetProperty(ref _activePlaylist, value);
+        }
+    }
+
+    public PlaylistsViewModel(IPlaylistManager playlistManager, IAudioPlayer audioPlayer)
     {
         _playlistManager = playlistManager;
         _playlistManager.PlaylistAdded += OnPlaylistAdded;
         _playlistManager.PlaylistRemoved += OnPlaylistRemoved;
         _playlistManager.CurrentPlaylistChanged += OnCurrentPlaylistChanged;
 
+        _audioPlayer = audioPlayer;
+        _audioPlayer.PlayingSongChanged += OnPlayingSongChanged;
+
         _playlists = new ObservableCollection<PlaylistItemViewModel>(_playlistManager.Playlists.Select(p => new PlaylistItemViewModel(p)));
         _selectedPlaylist = _playlists.FirstOrDefault(pv => pv.Playlist == _playlistManager.CurrentPlaylist);
     }
@@ -70,4 +87,9 @@ public partial class PlaylistsViewModel : ViewModelBase
             Playlists.Remove(playlistView);
         }
     }
+
+    private void OnPlayingSongChanged(object? sender, EventArgs e)
+    {
+        ActivePlaylist = Playlists.FirstOrDefault(pv => pv.Playlist == _audioPlayer.Playlist);
+    }
 }

Harmonia.WinUI/Views/PlaylistsView.xaml

@@ -12,8 +12,34 @@
     d:DataContext="{d:DesignInstance Type=vm:PlaylistsViewModel, IsDesignTimeCreatable=True}"
     mc:Ignorable="d">
     <UserControl.Resources>
+        <SolidColorBrush x:Key="PlaylistItemIconBrush" Color="#dddddd"/>
+        <SolidColorBrush x:Key="PlaylistItemTitleBrush" Color="#dddddd"/>
         <SolidColorBrush x:Key="PlaylistItemSubtitleBrush" Color="#aaaaaa"/>
 
+        <!-- Playlist Icon Path -->
+        <Style x:Key="PlaylistIconPath" TargetType="PathIcon">
+            <Setter Property="Foreground" Value="{StaticResource PlaylistItemIconBrush}"/>
+        </Style>
+
+        <Style x:Key="SelectedPlaylistIconPath" TargetType="PathIcon" BasedOn="{StaticResource PlaylistIconPath}">
+            <Setter Property="Foreground" Value="{StaticResource AccentTextFillColorPrimaryBrush}"/>
+        </Style>
+
+        <!-- Playlist Title Text Block -->
+        <Style x:Key="PlaylistTitleTextBlock" TargetType="TextBlock">
+            <Setter Property="Foreground" Value="{StaticResource PlaylistItemTitleBrush}"/>
+            <Setter Property="FontSize" Value="15"/>
+            <Setter Property="FontWeight" Value="Medium"/>
+            <Setter Property="LineStackingStrategy" Value="BlockLineHeight"/>
+            <Setter Property="VerticalAlignment" Value="Center"/>
+            <Setter Property="TextTrimming" Value="CharacterEllipsis"/>
+            <Setter Property="LineHeight" Value="0"/>
+        </Style>
+
+        <Style x:Key="SelectedPlaylistTitleTextBlock" TargetType="TextBlock" BasedOn="{StaticResource PlaylistTitleTextBlock}">
+            <Setter Property="Foreground" Value="{StaticResource AccentTextFillColorPrimaryBrush}"/>
+        </Style>
+
         <!-- Playlist Item Subtitle Text Block -->
         <Style x:Key="PlaylistSubtitleTextBlock" TargetType="TextBlock">
             <Setter Property="Foreground" Value="{StaticResource PlaylistItemSubtitleBrush}"/>
@@ -23,26 +49,31 @@
             <Setter Property="LineHeight" Value="0"/>
         </Style>
 
+        <Style x:Key="SelectedPlaylistSubtitleTextBlock" TargetType="TextBlock" BasedOn="{StaticResource PlaylistSubtitleTextBlock}">
+            <Setter Property="Foreground" Value="{StaticResource AccentTextFillColorSecondaryBrush}"/>
+        </Style>
+
         <DataTemplate x:Key="PlaylistTemplate" x:DataType="vm:PlaylistItemViewModel">
-            <Grid>
+            <Grid x:Name="PlaylistListViewItem">
                 <Grid.ColumnDefinitions>
                     <ColumnDefinition Width="*" />
                     <ColumnDefinition Width="200" />
                 </Grid.ColumnDefinitions>
                 <StackPanel Grid.Column="0" Orientation="Horizontal" Spacing="8" VerticalAlignment="Center">
                     <Viewbox Height="24" Width="24">
-                        <PathIcon Data="{StaticResource MusicNoteList}" />
+                        <PathIcon x:Name="MusicNoteListPathIcon" Data="{StaticResource MusicNoteList}" />
                     </Viewbox>
-                    <TextBlock Text="{x:Bind Name, Mode=OneWay}" FontSize="16" VerticalAlignment="Center" />
+                    <TextBlock x:Name="PlaylistTitleTextBlock" Text="{x:Bind Name, Mode=OneWay}" Style="{StaticResource PlaylistTitleTextBlock}" />
                 </StackPanel>
                 <StackPanel Grid.Column="1" Orientation="Horizontal" HorizontalAlignment="Right" VerticalAlignment="Center" Spacing="8">
-                    <TextBlock Text="{x:Bind Summary, Mode=OneWay}" Style="{StaticResource PlaylistSubtitleTextBlock}" />
+                    <TextBlock x:Name="PlaylistSubtitleTextBlock" Text="{x:Bind Summary, Mode=OneWay}" Style="{StaticResource PlaylistSubtitleTextBlock}" />
                 </StackPanel>
             </Grid>
         </DataTemplate>
     </UserControl.Resources>
     <Grid Margin="10">
         <ListView
+            Name="PlaylistsListView"
             ItemsSource="{Binding Playlists, Mode=OneWay}"
             SelectedItem="{Binding SelectedPlaylist, Mode=TwoWay}"
             ItemTemplate="{StaticResource PlaylistTemplate}">

Harmonia.WinUI/Views/PlaylistsView.xaml.cs

@@ -1,12 +1,99 @@
+using CommunityToolkit.WinUI;
+using Harmonia.WinUI.ViewModels;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
+using System.ComponentModel;
 
 namespace Harmonia.WinUI.Views;
 
 public sealed partial class PlaylistsView : UserControl
 {
+    private readonly PlaylistsViewModel _viewModel;
+
     public PlaylistsView()
     {
         InitializeComponent();
+
+        _viewModel = (PlaylistsViewModel)DataContext;
+        _viewModel.PropertyChanging += OnViewModelPropertyChanging;
+        _viewModel.PropertyChanged += OnViewModelPropertyChanged;
+    }
+
+    private void OnViewModelPropertyChanging(object? sender, PropertyChangingEventArgs e)
+    {
+        switch (e.PropertyName)
+        {
+            case nameof(_viewModel.ActivePlaylist):
+                UpdateListViewItemStyle(PlaylistItemStyle.Normal);
+                break;
+        }
+    }
+
+    private void OnViewModelPropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        switch (e.PropertyName)
+        {
+            case nameof(_viewModel.ActivePlaylist):
+                UpdateListViewItemStyle(PlaylistItemStyle.Selected);
+                break;
+        }
+    }
+
+    private void UpdateListViewItemStyle(PlaylistItemStyle style)
+    {
+        ListViewItem listViewItem = (ListViewItem)PlaylistsListView.ContainerFromItem(_viewModel.ActivePlaylist);
+
+        if (listViewItem is null)
+            return;
+
+        FrameworkElement? frameworkElement = TryGetFrameworkElement(listViewItem, "PlaylistListViewItem");
+
+        if (frameworkElement == null)
+            return;
+
+        string playlistItemIconBrushName = style == PlaylistItemStyle.Selected ? "SelectedPlaylistIconPath" : "PlaylistIconPath";
+        string playlistItemTitleBrushName = style == PlaylistItemStyle.Selected ? "SelectedPlaylistTitleTextBlock" : "PlaylistTitleTextBlock";
+        string playlistItemSubtitleBrushName = style == PlaylistItemStyle.Selected ? "SelectedPlaylistSubtitleTextBlock" : "PlaylistSubtitleTextBlock";
+
+        UpdateElementStyle(frameworkElement, "MusicNoteListPathIcon", playlistItemIconBrushName);
+        UpdateElementStyle(frameworkElement, "PlaylistTitleTextBlock", playlistItemTitleBrushName);
+        UpdateElementStyle(frameworkElement, "PlaylistSubtitleTextBlock", playlistItemSubtitleBrushName);
+    }
+
+    private static FrameworkElement? TryGetFrameworkElement(ListViewItem listViewItem, string elementName)
+    {
+        if (listViewItem.Name == elementName)
+        {
+            return listViewItem;
+        }
+        else
+        {
+            if (listViewItem.FindDescendant(elementName) is not FrameworkElement frameworkElement)
+                return null;
+
+            return frameworkElement;
+        }
+    }
+
+    private void UpdateElementStyle(FrameworkElement dependencyObject, string elementName, string resourceName)
+    {
+        if (dependencyObject.FindDescendant(elementName) is not FrameworkElement frameworkElement)
+            return;
+
+        Resources.TryGetValue(resourceName, out object? resource);
+
+        if (resource == null)
+            Application.Current.Resources.TryGetValue(resourceName, out resource);
+
+        if (resource is not Style style)
+            return;
+
+        frameworkElement.Style = style;
     }
 }
+
+public enum PlaylistItemStyle
+{
+    Normal,
+    Selected
+}