Add user activities to multi subscreens.

osu.Game/Screens/Multi/Lounge/LoungeSubScreen.cs

@@ -14,6 +14,7 @@
 using osu.Game.Overlays;
 using osu.Game.Screens.Multi.Lounge.Components;
 using osu.Game.Screens.Multi.Match;
+using osu.Game.Users;
 
 namespace osu.Game.Screens.Multi.Lounge
 {
@@ -24,6 +25,8 @@ public class LoungeSubScreen : MultiplayerSubScreen
 
         protected FilterControl Filter;
 
+        protected override UserActivity InitialActivity => new UserActivity.SearchingForLobby();
+
         private readonly Bindable<bool> initialRoomsReceived = new Bindable<bool>();
 
         private Container content;

osu.Game/Screens/Multi/Match/MatchSubScreen.cs

@@ -21,6 +21,7 @@
 using osu.Game.Screens.Multi.Ranking;
 using osu.Game.Screens.Play;
 using osu.Game.Screens.Select;
+using osu.Game.Users;
 using Footer = osu.Game.Screens.Multi.Match.Components.Footer;
 
 namespace osu.Game.Screens.Multi.Match
@@ -60,6 +61,7 @@ public class MatchSubScreen : MultiplayerSubScreen, IPreviewTrackOwner
         public MatchSubScreen(Room room)
         {
             Title = room.RoomID.Value == null ? "New room" : room.Name.Value;
+            Activity.Value = new UserActivity.InLobby(room);
         }
 
         [BackgroundDependencyLoader]

osu.Game/Users/UserActivity.cs

@@ -3,6 +3,7 @@
 
 using osu.Game.Beatmaps;
 using osu.Game.Graphics;
+using osu.Game.Online.Multiplayer;
 using osu.Game.Rulesets;
 using osuTK.Graphics;
 
@@ -61,9 +62,21 @@ public class Spectating : UserActivity
             public override string Status => @"Spectating a game";
         }
 
+        public class SearchingForLobby : UserActivity
+        {
+            public override string Status => @"Looking for a lobby";
+        }
+
         public class InLobby : UserActivity
         {
             public override string Status => @"In a multiplayer lobby";
+
+            public readonly Room Room;
+
+            public InLobby(Room room)
+            {
+                Room = room;
+            }
         }
     }
 }