add random button

osu.Game/Screens/Select/FooterButtonRandom.cs

@@ -0,0 +1,56 @@
+// 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 osu.Framework.Graphics;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Input.Events;
+using osu.Game.Graphics.Sprites;
+using System;
+
+namespace osu.Game.Screens.Select
+{
+    public class FooterButtonRandom : FooterButton
+    {
+        private readonly SpriteText secondaryText;
+        private bool secondaryActive;
+
+        public FooterButtonRandom()
+        {
+            textContainer.Add(secondaryText = new OsuSpriteText
+            {
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                Text = @"rewind",
+                Alpha = 0
+            });
+        }
+
+        protected override bool OnKeyDown(KeyDownEvent e)
+        {
+            secondaryActive = e.ShiftPressed;
+            updateText();
+            return base.OnKeyDown(e);
+        }
+
+        protected override bool OnKeyUp(KeyUpEvent e)
+        {
+            secondaryActive = e.ShiftPressed;
+            updateText();
+            return base.OnKeyUp(e);
+        }
+
+        private void updateText()
+        {
+            if (secondaryActive)
+            {
+                spriteText.FadeOut(120, Easing.InQuad);
+                secondaryText.FadeIn(120, Easing.InQuad);
+            }
+            else
+            {
+                spriteText.FadeIn(120, Easing.InQuad);
+                secondaryText.FadeOut(120, Easing.InQuad);
+            }
+        }
+    }
+}