Sidebar button style pass.

osu.Game/Overlays/Options/Sidebar.cs

@@ -0,0 +1,78 @@
+//Copyright (c) 2007-2016 ppy Pty Ltd <contact@ppy.sh>.
+//Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using OpenTK;
+using OpenTK.Graphics;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.Transformations;
+using osu.Framework.Input;
+using osu.Framework.Threading;
+using osu.Game.Graphics;
+
+namespace osu.Game.Overlays.Options
+{
+    public class Sidebar : Container
+    {
+        private FlowContainer content;
+        internal const int default_width = 60, expanded_width = 200;
+        protected override Container<Drawable> Content => content;
+
+        public Sidebar()
+        {
+            RelativeSizeAxes = Axes.Y;
+            InternalChildren = new Drawable[]
+            {
+                new Box
+                {
+                    Colour = Color4.Black,
+                    RelativeSizeAxes = Axes.Both,
+                },
+                new SidebarScrollContainer
+                {
+                    Children = new []
+                    {
+                        content = new FlowContainer
+                        {
+                            Origin = Anchor.CentreLeft,
+                            Anchor = Anchor.CentreLeft,
+                            AutoSizeAxes = Axes.Y,
+                            RelativeSizeAxes = Axes.X,
+                            Direction = FlowDirection.VerticalOnly
+                        }
+                    }
+                },
+            };
+        }
+
+        private ScheduledDelegate expandEvent;
+        
+        protected override bool OnHover(InputState state)
+        {
+            expandEvent = Scheduler.AddDelayed(() =>
+            {
+                expandEvent = null;
+                ResizeTo(new Vector2(expanded_width, Height), 150, EasingTypes.OutQuad);
+            }, 750);
+            return true;
+        }
+        
+        protected override void OnHoverLost(InputState state)
+        {
+            expandEvent?.Cancel();
+            ResizeTo(new Vector2(default_width, Height), 150, EasingTypes.OutQuad);
+            base.OnHoverLost(state);
+        }
+
+        private class SidebarScrollContainer : ScrollContainer
+        {
+            public SidebarScrollContainer()
+            {
+                Content.Anchor = Anchor.CentreLeft;
+                Content.Origin = Anchor.CentreLeft;
+            }
+        }
+    }
+}