Add a container that provides an isolated gameplay context

osu.Game/Screens/OnlinePlay/Multiplayer/Spectate/GameplayIsolationContainer.cs

@@ -0,0 +1,43 @@
+// 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.Bindables;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.Mods;
+
+namespace osu.Game.Screens.OnlinePlay.Multiplayer.Spectate
+{
+    public class GameplayIsolationContainer : Container
+    {
+        [Cached]
+        private readonly Bindable<RulesetInfo> ruleset = new Bindable<RulesetInfo>();
+
+        [Cached]
+        private readonly Bindable<WorkingBeatmap> beatmap = new Bindable<WorkingBeatmap>();
+
+        [Cached]
+        private readonly Bindable<IReadOnlyList<Mod>> mods = new Bindable<IReadOnlyList<Mod>>();
+
+        public GameplayIsolationContainer(WorkingBeatmap beatmap, RulesetInfo ruleset, IReadOnlyList<Mod> mods)
+        {
+            this.beatmap.Value = beatmap;
+            this.ruleset.Value = ruleset;
+            this.mods.Value = mods;
+
+            beatmap.LoadTrack();
+        }
+
+        protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent)
+        {
+            var dependencies = new DependencyContainer(base.CreateChildDependencies(parent));
+            dependencies.CacheAs(ruleset.BeginLease(false));
+            dependencies.CacheAs(beatmap.BeginLease(false));
+            dependencies.CacheAs(mods.BeginLease(false));
+            return dependencies;
+        }
+    }
+}