Added osu!direct header and filter control

osu.Game/Graphics/UserInterface/OsuEnumDropdown.cs

@@ -0,0 +1,32 @@
+// 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 System.ComponentModel;
+using System.Reflection;
+using System.Collections.Generic;
+
+namespace osu.Game.Graphics.UserInterface
+{
+    public class OsuEnumDropdown<T> : OsuDropdown<T>
+    {
+        public OsuEnumDropdown()
+        {
+            if (!typeof(T).IsEnum)
+                throw new InvalidOperationException("SettingsDropdown 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;
+        }
+    }
+}