From 0be2dc9b2dee3eecb9fdac94a9f8e64745230d72 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Mon, 13 Apr 2020 20:12:51 +0900
Subject: [PATCH] Tidy up SectionsContainer class layout/ordering

---
 .../Graphics/Containers/SectionsContainer.cs  | 82 ++++++++++---------
 1 file changed, 43 insertions(+), 39 deletions(-)

diff --git a/osu.Game/Graphics/Containers/SectionsContainer.cs b/osu.Game/Graphics/Containers/SectionsContainer.cs
index 24c61ad11c..a3125614aa 100644
--- a/osu.Game/Graphics/Containers/SectionsContainer.cs
+++ b/osu.Game/Graphics/Containers/SectionsContainer.cs
@@ -17,12 +17,7 @@ namespace osu.Game.Graphics.Containers
     public class SectionsContainer<T> : Container<T>
         where T : Drawable
     {
-        private Drawable expandableHeader, fixedHeader, footer, headerBackground;
-        private readonly OsuScrollContainer scrollContainer;
-        private readonly Container headerBackgroundContainer;
-        private FlowContainer<T> scrollContentContainer;
-
-        protected override Container<T> Content => scrollContentContainer;
+        public Bindable<T> SelectedSection { get; } = new Bindable<T>();
 
         public Drawable ExpandableHeader
         {
@@ -84,6 +79,7 @@ namespace osu.Game.Graphics.Containers
 
                 headerBackgroundContainer.Clear();
                 headerBackground = value;
+
                 if (value == null) return;
 
                 headerBackgroundContainer.Add(headerBackground);
@@ -92,37 +88,17 @@ namespace osu.Game.Graphics.Containers
             }
         }
 
-        public Bindable<T> SelectedSection { get; } = new Bindable<T>();
+        protected override Container<T> Content => scrollContentContainer;
 
-        protected virtual FlowContainer<T> CreateScrollContentContainer()
-            => new FillFlowContainer<T>
-            {
-                Direction = FillDirection.Vertical,
-                AutoSizeAxes = Axes.Y,
-                RelativeSizeAxes = Axes.X,
-            };
-
-        public override void Add(T drawable)
-        {
-            base.Add(drawable);
-            lastKnownScroll = float.NaN;
-            headerHeight = float.NaN;
-            footerHeight = float.NaN;
-        }
+        private readonly OsuScrollContainer scrollContainer;
+        private readonly Container headerBackgroundContainer;
+        private readonly MarginPadding originalSectionsMargin;
+        private Drawable expandableHeader, fixedHeader, footer, headerBackground;
+        private FlowContainer<T> scrollContentContainer;
 
         private float headerHeight, footerHeight;
-        private readonly MarginPadding originalSectionsMargin;
 
-        private void updateSectionsMargin()
-        {
-            if (!Children.Any()) return;
-
-            var newMargin = originalSectionsMargin;
-            newMargin.Top += headerHeight;
-            newMargin.Bottom += footerHeight;
-
-            scrollContentContainer.Margin = newMargin;
-        }
+        private float lastKnownScroll;
 
         public SectionsContainer()
         {
@@ -133,22 +109,41 @@ namespace osu.Game.Graphics.Containers
                     s.RelativeSizeAxes = Axes.Both;
                     s.Masking = true;
                     s.ScrollbarVisible = false;
-                    s.Children = new Drawable[] { scrollContentContainer = CreateScrollContentContainer() };
+                    s.Child = scrollContentContainer = CreateScrollContentContainer();
                 }),
                 headerBackgroundContainer = new Container
                 {
                     RelativeSizeAxes = Axes.X
                 }
             });
+
             originalSectionsMargin = scrollContentContainer.Margin;
         }
 
+        public override void Add(T drawable)
+        {
+            base.Add(drawable);
+            lastKnownScroll = float.NaN;
+            headerHeight = float.NaN;
+            footerHeight = float.NaN;
+        }
+
+        public void ScrollTo(Drawable section) =>
+            scrollContainer.ScrollTo(scrollContainer.GetChildPosInContent(section) - (FixedHeader?.BoundingBox.Height ?? 0));
+
+        public void ScrollToTop() => scrollContainer.ScrollTo(0);
+
         [NotNull]
         protected virtual OsuScrollContainer CreateScrollContainer() => new OsuScrollContainer();
 
-        public void ScrollTo(Drawable section) => scrollContainer.ScrollTo(scrollContainer.GetChildPosInContent(section) - (FixedHeader?.BoundingBox.Height ?? 0));
-
-        public void ScrollToTop() => scrollContainer.ScrollTo(0);
+        [NotNull]
+        protected virtual FlowContainer<T> CreateScrollContentContainer() =>
+            new FillFlowContainer<T>
+            {
+                Direction = FillDirection.Vertical,
+                AutoSizeAxes = Axes.Y,
+                RelativeSizeAxes = Axes.X,
+            };
 
         protected override bool OnInvalidate(Invalidation invalidation, InvalidationSource source)
         {
@@ -163,8 +158,6 @@ namespace osu.Game.Graphics.Containers
             return result;
         }
 
-        private float lastKnownScroll;
-
         protected override void UpdateAfterChildren()
         {
             base.UpdateAfterChildren();
@@ -215,5 +208,16 @@ namespace osu.Game.Graphics.Containers
                     SelectedSection.Value = bestMatch;
             }
         }
+
+        private void updateSectionsMargin()
+        {
+            if (!Children.Any()) return;
+
+            var newMargin = originalSectionsMargin;
+            newMargin.Top += headerHeight;
+            newMargin.Bottom += footerHeight;
+
+            scrollContentContainer.Margin = newMargin;
+        }
     }
 }