From f868f03e1b75556418c8cfd6576781c3324d3fd7 Mon Sep 17 00:00:00 2001
From: Dan Balasescu <smoogipoo@smgi.me>
Date: Fri, 21 Feb 2025 16:38:55 +0900
Subject: [PATCH] Fix host change sounds playing when exiting multiplayer rooms

---
 .../Online/Multiplayer/MultiplayerClient.cs   |  6 +++++
 .../Multiplayer/MultiplayerRoomSounds.cs      | 27 ++++++-------------
 2 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/osu.Game/Online/Multiplayer/MultiplayerClient.cs b/osu.Game/Online/Multiplayer/MultiplayerClient.cs
index 97161cce48..2d445ea25a 100644
--- a/osu.Game/Online/Multiplayer/MultiplayerClient.cs
+++ b/osu.Game/Online/Multiplayer/MultiplayerClient.cs
@@ -51,6 +51,11 @@ namespace osu.Game.Online.Multiplayer
         /// </summary>
         public event Action<MultiplayerRoomUser>? UserKicked;
 
+        /// <summary>
+        /// Invoked when the room's host is changed.
+        /// </summary>
+        public event Action<MultiplayerRoomUser?>? HostChanged;
+
         /// <summary>
         /// Invoked when a new item is added to the playlist.
         /// </summary>
@@ -531,6 +536,7 @@ namespace osu.Game.Online.Multiplayer
                 Room.Host = user;
                 APIRoom.Host = user?.User;
 
+                HostChanged?.Invoke(user);
                 RoomUpdated?.Invoke();
             }, false);
 
diff --git a/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomSounds.cs b/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomSounds.cs
index d53e485c86..cdf4e96bad 100644
--- a/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomSounds.cs
+++ b/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomSounds.cs
@@ -1,7 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using System.Collections.Generic;
 using osu.Framework.Allocation;
 using osu.Framework.Audio;
 using osu.Framework.Audio.Sample;
@@ -20,7 +19,6 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
         private Sample? userJoinedSample;
         private Sample? userLeftSample;
         private Sample? userKickedSample;
-        private MultiplayerRoomUser? host;
 
         [BackgroundDependencyLoader]
         private void load(AudioManager audio)
@@ -35,25 +33,10 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
         {
             base.LoadComplete();
 
-            client.RoomUpdated += onRoomUpdated;
             client.UserJoined += onUserJoined;
             client.UserLeft += onUserLeft;
             client.UserKicked += onUserKicked;
-            updateState();
-        }
-
-        private void onRoomUpdated() => Scheduler.AddOnce(updateState);
-
-        private void updateState()
-        {
-            if (EqualityComparer<MultiplayerRoomUser>.Default.Equals(host, client.Room?.Host))
-                return;
-
-            // only play sound when the host changes from an already-existing host.
-            if (host != null)
-                Scheduler.AddOnce(() => hostChangedSample?.Play());
-
-            host = client.Room?.Host;
+            client.HostChanged += onHostChanged;
         }
 
         private void onUserJoined(MultiplayerRoomUser user)
@@ -65,16 +48,22 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
         private void onUserKicked(MultiplayerRoomUser user)
             => Scheduler.AddOnce(() => userKickedSample?.Play());
 
+        private void onHostChanged(MultiplayerRoomUser? host)
+        {
+            if (host != null)
+                Scheduler.AddOnce(() => hostChangedSample?.Play());
+        }
+
         protected override void Dispose(bool isDisposing)
         {
             base.Dispose(isDisposing);
 
             if (client.IsNotNull())
             {
-                client.RoomUpdated -= onRoomUpdated;
                 client.UserJoined -= onUserJoined;
                 client.UserLeft -= onUserLeft;
                 client.UserKicked -= onUserKicked;
+                client.HostChanged -= onHostChanged;
             }
         }
     }