Add ModFlowDisplay and consume in ContractedPanelMiddleContent

osu.Game/Screens/Play/HUD/ModFlowDisplay.cs

@@ -0,0 +1,83 @@
+// 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 System;
+using System.Collections.Generic;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.UserInterface;
+using osu.Game.Graphics.Containers;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.UI;
+using osuTK;
+
+namespace osu.Game.Screens.Play.HUD
+{
+    /// <summary>
+    /// A horizontally wrapping display of mods. For cases where wrapping is not required, use <see cref="ModDisplay"/> instead.
+    /// </summary>
+    public class ModFlowDisplay : ReverseChildIDFillFlowContainer<ModIcon>, IHasCurrentValue<IReadOnlyList<Mod>>
+    {
+        private const int fade_duration = 1000;
+
+        private readonly BindableWithCurrent<IReadOnlyList<Mod>> current = new BindableWithCurrent<IReadOnlyList<Mod>>();
+
+        public Bindable<IReadOnlyList<Mod>> Current
+        {
+            get => current.Current;
+            set
+            {
+                if (value == null)
+                    throw new ArgumentNullException(nameof(value));
+
+                current.Current = value;
+            }
+        }
+
+        private float iconScale = 1;
+
+        public float IconScale
+        {
+            get => iconScale;
+            set
+            {
+                iconScale = value;
+                updateDisplay();
+            }
+        }
+
+        public ModFlowDisplay()
+        {
+            Direction = FillDirection.Full;
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            Current.BindValueChanged(_ => updateDisplay(), true);
+
+            this.FadeInFromZero(fade_duration, Easing.OutQuint);
+        }
+
+        private void updateDisplay()
+        {
+            Clear();
+
+            if (current.Value == null) return;
+
+            Spacing = new Vector2(0, -12 * iconScale);
+
+            foreach (Mod mod in current.Value)
+            {
+                Add(new ModIcon(mod)
+                {
+                    Scale = new Vector2(0.6f * iconScale),
+                    Anchor = Anchor.TopCentre,
+                    Origin = Anchor.TopCentre,
+                });
+            }
+        }
+    }
+}