Updated certain events to have more concrete event arguments. Added try-catch block around playlist save logic. Added DispatchQueue where necessary.

Harmonia.Core/Player/AudioPlayer.cs

@@ -20,9 +20,13 @@ public class AudioPlayer : IAudioPlayer
         }
         protected set
         {
+            Playlist? oldPlaylist = _playlist;
             _playlist = value;
+
             NotifyPropertyChanged(nameof(Playlist));
-            PlaylistChanged?.Invoke(this, new());
+
+            PlaylistChangedEventArgs eventArgs = new(oldPlaylist, value);
+            PlaylistChanged?.Invoke(this, eventArgs);
         }
     }
 
@@ -37,9 +41,13 @@ public class AudioPlayer : IAudioPlayer
         }
         protected set
         {
+            PlaylistSong? oldSong = _playingSong;
             _playingSong = value;
+
             NotifyPropertyChanged(nameof(PlayingSong));
-            PlayingSongChanged?.Invoke(this, new());
+
+            PlayingSongChangedEventArgs eventArgs = new(oldSong, value);
+            PlayingSongChanged?.Invoke(this, eventArgs);
         }
     }
 
@@ -115,8 +123,8 @@ public class AudioPlayer : IAudioPlayer
 
     protected virtual int PreviousSongSecondsThreshold => 5;
 
-    public event EventHandler? PlaylistChanged;
-    public event EventHandler? PlayingSongChanged;
+    public event EventHandler<PlaylistChangedEventArgs>? PlaylistChanged;
+    public event EventHandler<PlayingSongChangedEventArgs>? PlayingSongChanged;
     public event PropertyChangedEventHandler? PropertyChanged;
 
     public AudioPlayer(IAudioEngine audioEngine, IPlaylistManager playlistManager)