Lock screen rotation while in gameplay.

osu.Android/GameplayScreenRotationLocker.cs

@@ -0,0 +1,31 @@
+// 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 Android.Content.PM;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Game;
+
+namespace osu.Android
+{
+    public class GameplayScreenRotationLocker : Component
+    {
+        private Bindable<bool> localUserPlaying;
+
+        [BackgroundDependencyLoader]
+        private void load(OsuGame game)
+        {
+            localUserPlaying = game.LocalUserPlaying.GetBoundCopy();
+            localUserPlaying.BindValueChanged(_ => updateLock());
+        }
+
+        private void updateLock()
+        {
+            OsuGameActivity.Activity.RunOnUiThread(() =>
+            {
+                OsuGameActivity.Activity.RequestedOrientation = localUserPlaying.Value ? ScreenOrientation.Locked : ScreenOrientation.FullUser;
+            });
+        }
+    }
+}