Rework OptionDropdowns to be more versatile

The existing OptionDropdown only supported enums and was thus renamed
to OptionEnumDropDown. A new OptionDropdown has been created in its
place to allow binding to arbitrary values, with a set of user-provided
items.

osu.Game/Overlays/Options/OptionDropdown.cs

@@ -7,6 +7,7 @@ using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.UserInterface;
 using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics.UserInterface;
+using System.Collections.Generic;
 
 namespace osu.Game.Overlays.Options
 {
@@ -56,10 +57,25 @@ namespace osu.Game.Overlays.Options
             base.Dispose(isDisposing);
         }
 
+        private IEnumerable<KeyValuePair<string, T>> items;
+        public IEnumerable<KeyValuePair<string, T>> Items
+        {
+            get
+            {
+                return items;
+            }
+            set
+            {
+                items = value;
+                if(dropdown != null)
+                    dropdown.Items = value;
+            }
+        }
+
         public OptionDropDown()
         {
-            if (!typeof(T).IsEnum)
+            Items = new KeyValuePair<string, T>[0];
-                throw new InvalidOperationException("OptionsDropdown only supports enums as the generic type argument");
+
             Direction = FlowDirection.VerticalOnly;
             RelativeSizeAxes = Axes.X;
             AutoSizeAxes = Axes.Y;
@@ -72,7 +88,7 @@ namespace osu.Game.Overlays.Options
                 {
                     Margin = new MarginPadding { Top = 5 },
                     RelativeSizeAxes = Axes.X,
-                    Items = (T[])Enum.GetValues(typeof(T)),
+                    Items = this.Items,
                 }
             };
             dropdown.ValueChanged += Dropdown_ValueChanged;

osu.Game/Overlays/Options/OptionEnumDropDown.cs

@@ -0,0 +1,37 @@
+using System;
+using osu.Framework.Configuration;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Primitives;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.UserInterface;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Graphics.UserInterface;
+using System.Reflection;
+using System.ComponentModel;
+using System.Collections.Generic;
+
+namespace osu.Game.Overlays.Options
+{
+    public class OptionEnumDropDown<T> : OptionDropDown<T>
+    {
+        public OptionEnumDropDown()
+        {
+            if (!typeof(T).IsEnum)
+                throw new InvalidOperationException("OptionsDropdown only supports enums as the generic type argument");
+
+            List<KeyValuePair<string, T>> items = new List<KeyValuePair<string, T>>();
+            foreach(var val in (T[])Enum.GetValues(typeof(T)))
+            {
+                var field = typeof(T).GetField(Enum.GetName(typeof(T), val));
+                items.Add(
+                    new KeyValuePair<string, T>(
+                        field.GetCustomAttribute<DescriptionAttribute>()?.Description ?? Enum.GetName(typeof(T), val),
+                        val
+                    )
+                );
+            }
+            Items = items;
+        }
+    }
+}

osu.Game/Overlays/Options/Sections/Gameplay/GeneralOptions.cs

@@ -23,12 +23,12 @@ namespace osu.Game.Overlays.Options.Sections.Gameplay
                     LabelText = "Background dim",
                     Bindable = (BindableInt)config.GetBindable<int>(OsuConfig.DimLevel)
                 },
-                new OptionDropDown<ProgressBarType>
+                new OptionEnumDropDown<ProgressBarType>
                 {
                     LabelText = "Progress display",
                     Bindable = config.GetBindable<ProgressBarType>(OsuConfig.ProgressBarType)
                 },
-                new OptionDropDown<ScoreMeterType>
+                new OptionEnumDropDown<ScoreMeterType>
                 {
                     LabelText = "Score meter type",
                     Bindable = config.GetBindable<ScoreMeterType>(OsuConfig.ScoreMeter)

osu.Game/Overlays/Options/Sections/General/UpdateOptions.cs

@@ -18,7 +18,7 @@ namespace osu.Game.Overlays.Options.Sections.General
         {
             Children = new Drawable[]
             {
-                new OptionDropDown<ReleaseStream>
+                new OptionEnumDropDown<ReleaseStream>
                 {
                     LabelText = "Release stream",
                     Bindable = config.GetBindable<ReleaseStream>(OsuConfig.ReleaseStream),

osu.Game/Overlays/Options/Sections/Graphics/DetailOptions.cs

@@ -57,7 +57,7 @@ namespace osu.Game.Overlays.Options.Sections.Graphics
                     LabelText = "Softening filter",
                     Bindable = config.GetBindable<bool>(OsuConfig.BloomSoftening)
                 },
-                new OptionDropDown<ScreenshotFormat>
+                new OptionEnumDropDown<ScreenshotFormat>
                 {
                     LabelText = "Screenshot",
                     Bindable = config.GetBindable<ScreenshotFormat>(OsuConfig.ScreenshotFormat)

osu.Game/Overlays/Options/Sections/Graphics/RendererOptions.cs

@@ -20,7 +20,7 @@ namespace osu.Game.Overlays.Options.Sections.Graphics
             Children = new Drawable[]
             {
                 // TODO: this needs to be a custom dropdown at some point
-                new OptionDropDown<FrameSync>
+                new OptionEnumDropDown<FrameSync>
                 {
                     LabelText = "Frame limiter",
                     Bindable = config.GetBindable<FrameSync>(FrameworkConfig.FrameSync)

osu.Game/Overlays/Options/Sections/Input/MouseOptions.cs

@@ -33,7 +33,7 @@ namespace osu.Game.Overlays.Options.Sections.Input
                     LabelText = "Map absolute raw input to the osu! window",
                     Bindable = config.GetBindable<bool>(OsuConfig.AbsoluteToOsuWindow)
                 },
-                new OptionDropDown<ConfineMouseMode>
+                new OptionEnumDropDown<ConfineMouseMode>
                 {
                     LabelText = "Confine mouse cursor",
                     Bindable = config.GetBindable<ConfineMouseMode>(OsuConfig.ConfineMouse),

osu.Game/osu.Game.csproj

@@ -99,6 +99,7 @@
     <Compile Include="Beatmaps\Timing\SampleChange.cs" />
     <Compile Include="Beatmaps\Timing\TimingChange.cs" />
     <Compile Include="Configuration\OsuConfigManager.cs" />
+    <Compile Include="Overlays\Options\OptionDropDown.cs" />
     <Compile Include="Overlays\Options\OptionLabel.cs" />
     <Compile Include="Graphics\UserInterface\OsuDropDownHeader.cs" />
     <Compile Include="Graphics\UserInterface\OsuDropDownMenu.cs" />
@@ -239,7 +240,7 @@
     <Compile Include="Overlays\Options\OptionTextBox.cs" />
     <Compile Include="Overlays\Options\OptionSlider.cs" />
     <Compile Include="Configuration\ProgressBarType.cs" />
-    <Compile Include="Overlays\Options\OptionDropDown.cs" />
+    <Compile Include="Overlays\Options\OptionEnumDropDown.cs" />
     <Compile Include="Configuration\RankingType.cs" />
     <Compile Include="Configuration\ScoreMeterType.cs" />
     <Compile Include="Configuration\ReleaseStream.cs" />