Added randomize/reverse songs logic. Added initial UI-side locking logic.

Harmonia.Core/Playlists/Playlist.cs

@@ -14,6 +14,36 @@ public class Playlist
 
     public event EventHandler<PlaylistUpdatedEventArgs>? PlaylistUpdated;
 
+    public void Lock()
+    {
+        IsLocked = true;
+
+        PlaylistUpdatedEventArgs eventArgs = new()
+        {
+            Action = PlaylistUpdateAction.Lock,
+            Index = -1,
+            Count = 0,
+            Songs = []
+        };
+
+        PlaylistUpdated?.Invoke(this, eventArgs);
+    }
+
+    public void Unlock()
+    {
+        IsLocked = false;
+
+        PlaylistUpdatedEventArgs eventArgs = new()
+        {
+            Action = PlaylistUpdateAction.Unlock,
+            Index = -1,
+            Count = 0,
+            Songs = []
+        };
+
+        PlaylistUpdated?.Invoke(this, eventArgs);
+    }
+
     public void AddSong(Song song, int? index = null)
     {
         AddSongs([song], index);
@@ -83,6 +113,9 @@ public class Playlist
 
     public void SortSongs(PlaylistSong[] playlistSongs, SortOption[] sortOptions)
     {
+        if (IsLocked)
+            return;
+
         Dictionary<int, PlaylistSong> oldPlaylistSongs = playlistSongs
             .OrderBy(Songs.IndexOf)
             .ToDictionary(Songs.IndexOf, playlistSong => playlistSong);
@@ -116,6 +149,50 @@ public class Playlist
         PlaylistUpdated?.Invoke(this, eventArgs);
     }
 
+    public void Randomize(PlaylistSong[] playlistSongs)
+    {
+        if (IsLocked)
+            return;
+
+        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];
+
+        PlaylistUpdatedEventArgs eventArgs = new()
+        {
+            Action = PlaylistUpdateAction.Reset,
+            Index = -1,
+            Count = playlistSongs.Length,
+            Songs = playlistSongs
+        };
+
+        PlaylistUpdated?.Invoke(this, eventArgs);
+    }
+
+    public void Reverse(PlaylistSong[] playlistSongs)
+    {
+        if (IsLocked)
+            return;
+
+        int[] originalIndexes = [.. playlistSongs.Select(playlistSong => Songs.IndexOf(playlistSong))];
+        PlaylistSong[] reversedSongs = [.. originalIndexes.Select(i => Songs[i]).Reverse()];
+
+        for (int i = 0; i < originalIndexes.Length; i++)
+            Songs[originalIndexes[i]] = reversedSongs[i];
+
+        PlaylistUpdatedEventArgs eventArgs = new()
+        {
+            Action = PlaylistUpdateAction.Reset,
+            Index = -1,
+            Count = playlistSongs.Length,
+            Songs = playlistSongs
+        };
+
+        PlaylistUpdated?.Invoke(this, eventArgs);
+    }
+
     public void RemoveSong(int index)
     {
         RemoveSongs(index, 1);

Harmonia.Core/Playlists/PlaylistUpdateAction.cs

@@ -21,5 +21,7 @@ public enum PlaylistUpdateAction
     /// <summary>
     /// The tags of the songs in the collection were refreshed.
     /// </summary>
-    Refresh
+    Refresh,
+    Lock,
+    Unlock
 }