From ee35422efc0396ec7800933ae4e2e51abfb45140 Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Wed, 29 Nov 2017 18:38:12 +0900
Subject: [PATCH] Handle rulesets that don't support composition a bit better

---
 osu.Game/Screens/Edit/Editor.cs                  |  1 +
 osu.Game/Screens/Edit/Screens/Compose/Compose.cs | 10 +++++-----
 osu.Game/Screens/Edit/Screens/EditorScreen.cs    |  3 +++
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/osu.Game/Screens/Edit/Editor.cs b/osu.Game/Screens/Edit/Editor.cs
index 607ff792d8..bc86c683c7 100644
--- a/osu.Game/Screens/Edit/Editor.cs
+++ b/osu.Game/Screens/Edit/Editor.cs
@@ -154,6 +154,7 @@ namespace osu.Game.Screens.Edit
             }
 
             currentScreen.Beatmap.BindTo(Beatmap);
+            currentScreen.ExitRequested = Exit;
             screenContainer.Add(currentScreen);
         }
 
diff --git a/osu.Game/Screens/Edit/Screens/Compose/Compose.cs b/osu.Game/Screens/Edit/Screens/Compose/Compose.cs
index 8cfb04da06..6954995340 100644
--- a/osu.Game/Screens/Edit/Screens/Compose/Compose.cs
+++ b/osu.Game/Screens/Edit/Screens/Compose/Compose.cs
@@ -7,6 +7,7 @@ using osu.Framework.Extensions.Color4Extensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
+using osu.Framework.Logging;
 using osu.Framework.Timing;
 using osu.Game.Beatmaps;
 using osu.Game.Screens.Edit.Screens.Compose.Timeline;
@@ -76,18 +77,17 @@ namespace osu.Game.Screens.Edit.Screens.Compose
             };
 
             timeline.Beatmap.BindTo(Beatmap);
-
             Beatmap.ValueChanged += beatmapChanged;
         }
 
         private void beatmapChanged(WorkingBeatmap newBeatmap)
         {
-            var ruleset = newBeatmap.BeatmapInfo.Ruleset.CreateInstance();
-            var composer = ruleset.CreateHitObjectComposer();
+            var ruleset = newBeatmap.BeatmapInfo.Ruleset?.CreateInstance();
+            var composer = ruleset?.CreateHitObjectComposer();
             if (composer == null)
             {
-                // Todo: Handle this
-                //throw new InvalidOperationException($"Ruleset {ruleset.Description} doesn't support hitobject composition.");
+                Logger.Log($"Ruleset {ruleset.Description} doesn't support hitobject composition.");
+                ExitRequested?.Invoke();
                 return;
             }
 
diff --git a/osu.Game/Screens/Edit/Screens/EditorScreen.cs b/osu.Game/Screens/Edit/Screens/EditorScreen.cs
index ac248930d8..9a158d20f1 100644
--- a/osu.Game/Screens/Edit/Screens/EditorScreen.cs
+++ b/osu.Game/Screens/Edit/Screens/EditorScreen.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using osu.Framework.Configuration;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -10,6 +11,8 @@ namespace osu.Game.Screens.Edit.Screens
 {
     public class EditorScreen : Container
     {
+        public Action ExitRequested;
+
         public readonly Bindable<WorkingBeatmap> Beatmap = new Bindable<WorkingBeatmap>();
 
         protected override Container<Drawable> Content => content;