From 8e1ed1c621d12c4b1a1f97812968043b8eb7017c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=82=BA=E4=BB=80=E9=BA=BC?= <andy840119@gmail.com>
Date: Sun, 10 Jul 2022 10:09:32 +0800
Subject: [PATCH] Mark CreateHitObjectComposer() accept null. And add the null
 check in the test case.

---
 osu.Game.Tests/Visual/Editing/TimelineTestScene.cs | 8 +++++++-
 osu.Game/Rulesets/Ruleset.cs                       | 2 +-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/osu.Game.Tests/Visual/Editing/TimelineTestScene.cs b/osu.Game.Tests/Visual/Editing/TimelineTestScene.cs
index 437f06c47f..7c11b4aa56 100644
--- a/osu.Game.Tests/Visual/Editing/TimelineTestScene.cs
+++ b/osu.Game.Tests/Visual/Editing/TimelineTestScene.cs
@@ -39,7 +39,13 @@ namespace osu.Game.Tests.Visual.Editing
             Dependencies.Cache(EditorBeatmap);
             Dependencies.CacheAs<IBeatSnapProvider>(EditorBeatmap);
 
-            Composer = playable.BeatmapInfo.Ruleset.CreateInstance().CreateHitObjectComposer().With(d => d.Alpha = 0);
+            Composer = playable.BeatmapInfo.Ruleset.CreateInstance().CreateHitObjectComposer().With(d =>
+            {
+                if (d == null)
+                    return;
+
+                d.Alpha = 0;
+            });
 
             Add(new OsuContextMenuContainer
             {
diff --git a/osu.Game/Rulesets/Ruleset.cs b/osu.Game/Rulesets/Ruleset.cs
index bd2d147a08..2cab529a4b 100644
--- a/osu.Game/Rulesets/Ruleset.cs
+++ b/osu.Game/Rulesets/Ruleset.cs
@@ -236,7 +236,7 @@ namespace osu.Game.Rulesets
         /// <returns>A performance calculator instance for the provided score.</returns>
         public virtual PerformanceCalculator? CreatePerformanceCalculator() => null;
 
-        public virtual HitObjectComposer CreateHitObjectComposer() => null;
+        public virtual HitObjectComposer? CreateHitObjectComposer() => null;
 
         public virtual IBeatmapVerifier? CreateBeatmapVerifier() => null;