Fix ModIcon not updating background colour correctly

osu.Game.Tests/Visual/UserInterface/TestSceneModIcon.cs

@@ -0,0 +1,21 @@
+// 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 NUnit.Framework;
+using osu.Game.Rulesets.Osu.Mods;
+using osu.Game.Rulesets.UI;
+
+namespace osu.Game.Tests.Visual.UserInterface
+{
+    public class TestSceneModIcon : OsuTestScene
+    {
+        [Test]
+        public void TestChangeModType()
+        {
+            ModIcon icon = null;
+
+            AddStep("create mod icon", () => Child = icon = new ModIcon(new OsuModDoubleTime()));
+            AddStep("change mod", () => icon.Mod = new OsuModEasy());
+        }
+    }
+}

osu.Game/Rulesets/UI/ModIcon.cs

@@ -29,8 +29,6 @@ namespace osu.Game.Rulesets.UI
 
         private const float size = 80;
 
-        private readonly ModType type;
-
         public virtual string TooltipText => showTooltip ? mod.IconTooltip : null;
 
         private Mod mod;
@@ -42,10 +40,18 @@ namespace osu.Game.Rulesets.UI
             set
             {
                 mod = value;
-                updateMod(value);
+
+                if (IsLoaded)
+                    updateMod(value);
             }
         }
 
+        [Resolved]
+        private OsuColour colours { get; set; }
+
+        private Color4 backgroundColour;
+        private Color4 highlightedColour;
+
         /// <summary>
         /// Construct a new instance.
         /// </summary>
@@ -56,8 +62,6 @@ namespace osu.Game.Rulesets.UI
             this.mod = mod ?? throw new ArgumentNullException(nameof(mod));
             this.showTooltip = showTooltip;
 
-            type = mod.Type;
-
             Size = new Vector2(size);
 
             Children = new Drawable[]
@@ -89,6 +93,13 @@ namespace osu.Game.Rulesets.UI
                     Icon = FontAwesome.Solid.Question
                 },
             };
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            Selected.BindValueChanged(_ => updateColour());
 
             updateMod(mod);
         }
@@ -102,20 +113,14 @@ namespace osu.Game.Rulesets.UI
             {
                 modIcon.FadeOut();
                 modAcronym.FadeIn();
-                return;
+            }
+            else
+            {
+                modIcon.FadeIn();
+                modAcronym.FadeOut();
             }
 
-            modIcon.FadeIn();
+            switch (value.Type)
-            modAcronym.FadeOut();
-        }
-
-        private Color4 backgroundColour;
-        private Color4 highlightedColour;
-
-        [BackgroundDependencyLoader]
-        private void load(OsuColour colours)
-        {
-            switch (type)
             {
                 default:
                 case ModType.DifficultyIncrease:
@@ -149,12 +154,13 @@ namespace osu.Game.Rulesets.UI
                     modIcon.Colour = colours.Yellow;
                     break;
             }
+
+            updateColour();
         }
 
-        protected override void LoadComplete()
+        private void updateColour()
         {
-            base.LoadComplete();
+            background.Colour = Selected.Value ? highlightedColour : backgroundColour;
-            Selected.BindValueChanged(selected => background.Colour = selected.NewValue ? highlightedColour : backgroundColour, true);
         }
     }
 }