From 1c47773e0dac8fbd7f1d855fc59f88c03a044059 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20M=C3=BCller?= <thomas94@gmx.net>
Date: Sat, 12 Nov 2016 13:08:34 +0100
Subject: [PATCH] Make sidebar behaviour feel a bit nicer.

---
 osu.Game/Overlays/OptionsOverlay.cs | 37 ++++++++++++++++-------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/osu.Game/Overlays/OptionsOverlay.cs b/osu.Game/Overlays/OptionsOverlay.cs
index d29580adfa..6f79fedf88 100644
--- a/osu.Game/Overlays/OptionsOverlay.cs
+++ b/osu.Game/Overlays/OptionsOverlay.cs
@@ -22,6 +22,7 @@
 using osu.Game.Overlays.Options.Graphics;
 using osu.Game.Overlays.Options.Input;
 using osu.Game.Overlays.Options.Online;
+using System;
 
 namespace osu.Game.Overlays
 {
@@ -112,8 +113,7 @@ public OptionsOverlay()
                         {
                             Selected = sections[0] == section,
                             Section = section,
-                            Action = () => scrollContainer.ScrollTo(
-                                scrollContainer.GetChildYInContent(section) - scrollContainer.DrawSize.Y / 2),
+                            Action = () => scrollContainer.ScrollIntoView(section),
                         }
                     ).ToArray()
                 }
@@ -130,26 +130,31 @@ protected override void Update()
         {
             base.Update();
 
-            if (scrollContainer.Current != lastKnownScroll)
+            float currentScroll = scrollContainer.Current;
+            if (currentScroll != lastKnownScroll)
             {
-                lastKnownScroll = scrollContainer.Current;
+                lastKnownScroll = currentScroll;
 
-                for (int i = sections.Length - 1; i >= 0; i--)
+                OptionsSection bestCandidate = null;
+                float bestDistance = float.MaxValue;
+
+                foreach (OptionsSection section in sections)
                 {
-                    var section = sections[i];
-                    float y = scrollContainer.GetChildYInContent(section) - scrollContainer.Current;
-                    if (y <= scrollContainer.DrawSize.Y / 2 + 25)
+                    float distance = Math.Abs(scrollContainer.GetChildYInContent(section) - currentScroll);
+                    if (distance < bestDistance)
                     {
-                        var previous = sidebarButtons.SingleOrDefault(sb => sb.Selected);
-                        var next = sidebarButtons.SingleOrDefault(sb => sb.Section == section);
-                        if (next != null)
-                        {
-                            previous.Selected = false;
-                            next.Selected = true;
-                        }
-                        break;
+                        bestDistance = distance;
+                        bestCandidate = section;
                     }
                 }
+
+                var previous = sidebarButtons.SingleOrDefault(sb => sb.Selected);
+                var next = sidebarButtons.SingleOrDefault(sb => sb.Section == bestCandidate);
+                if (next != null)
+                {
+                    previous.Selected = false;
+                    next.Selected = true;
+                }
             }
         }