Added playlists view. Added messaging service. Added logic for adding and deleting playlists.

Harmonia.WinUI/ViewModels/PlaylistsViewModel.cs

@@ -0,0 +1,65 @@
+using Harmonia.Core.Playlists;
+using System;
+using System.Collections.ObjectModel;
+
+namespace Harmonia.WinUI.ViewModels;
+
+public partial class PlaylistsViewModel : ViewModelBase
+{
+    private readonly IPlaylistManager _playlistManager;
+
+    private ObservableCollection<Playlist> _playlists = [];
+    public ObservableCollection<Playlist> Playlists
+    {
+        get
+        {
+            return _playlists;
+        }
+        set
+        {
+            SetProperty(ref _playlists, value);
+        }
+    }
+
+    private Playlist? _selectedPlaylist = null;
+    public Playlist? SelectedPlaylist
+    {
+        get
+        {
+            return _selectedPlaylist;
+        }
+        set
+        {
+            if (SetProperty(ref _selectedPlaylist, value))
+            {
+                _playlistManager.CurrentPlaylist = value;
+            }
+        }
+    }
+
+    public PlaylistsViewModel(IPlaylistManager playlistManager)
+    {
+        _playlistManager = playlistManager;
+        _playlistManager.PlaylistAdded += OnPlaylistAdded;
+        _playlistManager.PlaylistRemoved += OnPlaylistRemoved;
+        _playlistManager.CurrentPlaylistChanged += OnCurrentPlaylistChanged;
+
+        _playlists = new(_playlistManager.Playlists);
+        _selectedPlaylist = _playlistManager.CurrentPlaylist;
+    }
+
+    private void OnCurrentPlaylistChanged(object? sender, EventArgs e)
+    {
+        SelectedPlaylist = _playlistManager.CurrentPlaylist;
+    }
+
+    private void OnPlaylistAdded(object? sender, PlaylistAddedEventArgs e)
+    {
+        Playlists.Add(e.Playlist);
+    }
+
+    private void OnPlaylistRemoved(object? sender, PlaylistRemovedEventArgs e)
+    {
+        Playlists.Remove(e.Playlist);
+    }
+}