Add support for custom controls to SettingSourceAttribute

osu.Game.Tests/Mods/SettingsSourceAttributeTest.cs

@@ -4,7 +4,10 @@
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.UserInterface;
 using osu.Game.Configuration;
+using osu.Game.Overlays.Settings;
 
 namespace osu.Game.Tests.Mods
 {
@@ -26,6 +29,16 @@ namespace osu.Game.Tests.Mods
             Assert.That(orderedSettings[3].Item2.Name, Is.EqualTo(nameof(ClassWithSettings.UnorderedSetting)));
         }
 
+        [Test]
+        public void TestCustomControl()
+        {
+            var objectWithCustomSettingControl = new ClassWithCustomSettingControl();
+            var settings = objectWithCustomSettingControl.CreateSettingsControls().ToArray();
+
+            Assert.That(settings, Has.Length.EqualTo(1));
+            Assert.That(settings[0], Is.TypeOf<CustomSettingsControl>());
+        }
+
         private class ClassWithSettings
         {
             [SettingSource("Unordered setting", "Should be last")]
@@ -40,5 +53,21 @@ namespace osu.Game.Tests.Mods
             [SettingSource("Third setting", "Yet another description", 3)]
             public BindableInt ThirdSetting { get; set; } = new BindableInt();
         }
+
+        private class ClassWithCustomSettingControl
+        {
+            [SettingSource("Custom setting", "Should be a custom control", SettingControlType = typeof(CustomSettingsControl))]
+            public BindableInt UnorderedSetting { get; set; } = new BindableInt();
+        }
+
+        private class CustomSettingsControl : SettingsItem<int>
+        {
+            protected override Drawable CreateControl() => new CustomControl();
+
+            private class CustomControl : Drawable, IHasCurrentValue<int>
+            {
+                public Bindable<int> Current { get; set; } = new Bindable<int>();
+            }
+        }
     }
 }

osu.Game/Configuration/SettingSourceAttribute.cs

@@ -1,12 +1,15 @@
 // 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.
 
+#nullable enable
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using JetBrains.Annotations;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions.TypeExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Localisation;
 using osu.Game.Overlays.Settings;
@@ -31,7 +34,15 @@ namespace osu.Game.Configuration
 
         public int? OrderPosition { get; }
 
-        public SettingSourceAttribute(string label, string description = null)
+        /// <summary>
+        /// The type of the settings control which handles this setting source.
+        /// </summary>
+        /// <remarks>
+        /// Must be a type deriving <see cref="SettingsItem{T}"/> with a public constructor.
+        /// </remarks>
+        public Type? SettingControlType { get; set; }
+
+        public SettingSourceAttribute(string? label, string? description = null)
         {
             Label = label ?? string.Empty;
             Description = description ?? string.Empty;
@@ -67,6 +78,22 @@ namespace osu.Game.Configuration
             {
                 object value = property.GetValue(obj);
 
+                if (attr.SettingControlType != null)
+                {
+                    var controlType = attr.SettingControlType;
+                    if (controlType.EnumerateBaseTypes().All(t => !t.IsGenericType || t.GetGenericTypeDefinition() != typeof(SettingsItem<>)))
+                        throw new InvalidOperationException($"{nameof(SettingSourceAttribute)} had an unsupported custom control type ({controlType.ReadableName()})");
+
+                    var control = (Drawable)Activator.CreateInstance(controlType);
+                    controlType.GetProperty(nameof(SettingsItem<object>.LabelText))?.SetValue(control, attr.Label);
+                    controlType.GetProperty(nameof(SettingsItem<object>.TooltipText))?.SetValue(control, attr.Description);
+                    controlType.GetProperty(nameof(SettingsItem<object>.Current))?.SetValue(control, value);
+
+                    yield return control;
+
+                    continue;
+                }
+
                 switch (value)
                 {
                     case BindableNumber<float> bNumber: