From c3a98b6ad15475a86565c2501fe0faeb2e898b14 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Thu, 18 Feb 2021 16:59:43 +0900
Subject: [PATCH 1/2] Fix carousel items' borders getting blown out when
 selected and hovered

I tried restructuring the hierarchy to avoid needing this added property
(moving the hover layer out of the border container) but this leads to
some subpixel leakage outside the borders which looks even worse.

Closes #6915.
---
 .../Screens/Select/Carousel/CarouselHeader.cs | 34 +++++++++++++++++--
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/osu.Game/Screens/Select/Carousel/CarouselHeader.cs b/osu.Game/Screens/Select/Carousel/CarouselHeader.cs
index 947334c747..73324894ee 100644
--- a/osu.Game/Screens/Select/Carousel/CarouselHeader.cs
+++ b/osu.Game/Screens/Select/Carousel/CarouselHeader.cs
@@ -24,9 +24,13 @@ namespace osu.Game.Screens.Select.Carousel
         public Container BorderContainer;
 
         public readonly Bindable<CarouselItemState> State = new Bindable<CarouselItemState>(CarouselItemState.NotSelected);
+        private HoverLayer hoverLayer;
 
         protected override Container<Drawable> Content { get; } = new Container { RelativeSizeAxes = Axes.Both };
 
+        private const float corner_radius = 10;
+        private const float border_thickness = 2.5f;
+
         public CarouselHeader()
         {
             RelativeSizeAxes = Axes.X;
@@ -36,12 +40,12 @@ namespace osu.Game.Screens.Select.Carousel
             {
                 RelativeSizeAxes = Axes.Both,
                 Masking = true,
-                CornerRadius = 10,
+                CornerRadius = corner_radius,
                 BorderColour = new Color4(221, 255, 255, 255),
                 Children = new Drawable[]
                 {
                     Content,
-                    new HoverLayer()
+                    hoverLayer = new HoverLayer()
                 }
             };
         }
@@ -59,6 +63,8 @@ namespace osu.Game.Screens.Select.Carousel
             {
                 case CarouselItemState.Collapsed:
                 case CarouselItemState.NotSelected:
+                    hoverLayer.InsetForBorder = false;
+
                     BorderContainer.BorderThickness = 0;
                     BorderContainer.EdgeEffect = new EdgeEffectParameters
                     {
@@ -70,7 +76,9 @@ namespace osu.Game.Screens.Select.Carousel
                     break;
 
                 case CarouselItemState.Selected:
-                    BorderContainer.BorderThickness = 2.5f;
+                    hoverLayer.InsetForBorder = true;
+
+                    BorderContainer.BorderThickness = border_thickness;
                     BorderContainer.EdgeEffect = new EdgeEffectParameters
                     {
                         Type = EdgeEffectType.Glow,
@@ -107,6 +115,26 @@ namespace osu.Game.Screens.Select.Carousel
                 sampleHover = audio.Samples.Get("SongSelect/song-ping");
             }
 
+            public bool InsetForBorder
+            {
+                set
+                {
+                    if (value)
+                    {
+                        // apply same border as above to avoid applying additive overlay to it (and blowing out the colour).
+                        Masking = true;
+                        CornerRadius = corner_radius;
+                        BorderThickness = border_thickness;
+                    }
+                    else
+                    {
+                        BorderThickness = 0;
+                        CornerRadius = 0;
+                        Masking = false;
+                    }
+                }
+            }
+
             protected override bool OnHover(HoverEvent e)
             {
                 box.FadeIn(100, Easing.OutQuint);

From b713eb2eae259e086ca3b62ff6e3d7b79bed06a4 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Thu, 18 Feb 2021 17:13:48 +0900
Subject: [PATCH 2/2] Make field readonly

---
 osu.Game/Screens/Select/Carousel/CarouselHeader.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/osu.Game/Screens/Select/Carousel/CarouselHeader.cs b/osu.Game/Screens/Select/Carousel/CarouselHeader.cs
index 73324894ee..2fbf64de29 100644
--- a/osu.Game/Screens/Select/Carousel/CarouselHeader.cs
+++ b/osu.Game/Screens/Select/Carousel/CarouselHeader.cs
@@ -24,7 +24,8 @@ namespace osu.Game.Screens.Select.Carousel
         public Container BorderContainer;
 
         public readonly Bindable<CarouselItemState> State = new Bindable<CarouselItemState>(CarouselItemState.NotSelected);
-        private HoverLayer hoverLayer;
+
+        private readonly HoverLayer hoverLayer;
 
         protected override Container<Drawable> Content { get; } = new Container { RelativeSizeAxes = Axes.Both };