Add support for removing colours from palette

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

@@ -5,6 +5,7 @@ using NUnit.Framework;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Utils;
+using osu.Game.Graphics.Cursor;
 using osu.Game.Graphics.UserInterfaceV2;
 using osuTK.Graphics;
 
@@ -34,6 +35,9 @@ namespace osu.Game.Tests.Visual.UserInterface
         {
             AddStep("create component", () =>
             {
+                Child = new OsuContextMenuContainer
+                {
+                    RelativeSizeAxes = Axes.Both,
                     Child = new Container
                     {
                         Anchor = Anchor.Centre,
@@ -46,6 +50,7 @@ namespace osu.Game.Tests.Visual.UserInterface
                             Origin = Anchor.Centre,
                             ColourNamePrefix = "My colour #"
                         }
+                    }
                 };
 
                 component.Label = "a sample component";

osu.Game/Graphics/UserInterfaceV2/ColourDisplay.cs

@@ -1,6 +1,7 @@
 // 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 osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions;
@@ -12,6 +13,7 @@ using osu.Framework.Graphics.UserInterface;
 using osu.Framework.Localisation;
 using osu.Game.Graphics.Containers;
 using osu.Game.Graphics.Sprites;
+using osu.Game.Graphics.UserInterface;
 using osuTK;
 
 namespace osu.Game.Graphics.UserInterfaceV2
@@ -19,12 +21,17 @@ namespace osu.Game.Graphics.UserInterfaceV2
     /// <summary>
     /// A component which displays a colour along with related description text.
     /// </summary>
-    public class ColourDisplay : CompositeDrawable, IHasCurrentValue<Colour4>, IHasPopover
+    public class ColourDisplay : CompositeDrawable, IHasCurrentValue<Colour4>
     {
+        /// <summary>
+        /// Invoked when the user has requested the colour corresponding to this <see cref="ColourDisplay"/>
+        /// to be removed from its palette.
+        /// </summary>
+        public event Action<ColourDisplay> DeleteRequested;
+
         private readonly BindableWithCurrent<Colour4> current = new BindableWithCurrent<Colour4>();
 
-        private Box fill;
+        private OsuClickableContainer colourCircle;
-        private OsuSpriteText colourHexCode;
         private OsuSpriteText colourName;
 
         public Bindable<Colour4> Current
@@ -63,12 +70,37 @@ namespace osu.Game.Graphics.UserInterfaceV2
                 Spacing = new Vector2(0, 10),
                 Children = new Drawable[]
                 {
-                    new OsuClickableContainer
+                    colourCircle = new ColourCircle
                     {
-                        RelativeSizeAxes = Axes.X,
+                        Current = { BindTarget = Current },
-                        Height = 100,
+                        DeleteRequested = () => DeleteRequested?.Invoke(this)
-                        CornerRadius = 50,
+                    },
-                        Masking = true,
+                    colourName = new OsuSpriteText
+                    {
+                        Anchor = Anchor.TopCentre,
+                        Origin = Anchor.TopCentre
+                    }
+                }
+            };
+        }
+
+        private class ColourCircle : OsuClickableContainer, IHasPopover, IHasContextMenu
+        {
+            public Bindable<Colour4> Current { get; } = new Bindable<Colour4>();
+
+            public Action DeleteRequested { get; set; }
+
+            private readonly Box fill;
+            private readonly OsuSpriteText colourHexCode;
+
+            public ColourCircle()
+            {
+                RelativeSizeAxes = Axes.X;
+                Height = 100;
+                CornerRadius = 50;
+                Masking = true;
+                Action = this.ShowPopover;
+
                 Children = new Drawable[]
                 {
                     fill = new Box
@@ -81,15 +113,6 @@ namespace osu.Game.Graphics.UserInterfaceV2
                         Origin = Anchor.Centre,
                         Font = OsuFont.Default.With(size: 12)
                     }
-                        },
-                        Action = this.ShowPopover
-                    },
-                    colourName = new OsuSpriteText
-                    {
-                        Anchor = Anchor.TopCentre,
-                        Origin = Anchor.TopCentre
-                    }
-                }
                 };
             }
 
@@ -97,14 +120,14 @@ namespace osu.Game.Graphics.UserInterfaceV2
             {
                 base.LoadComplete();
 
-            current.BindValueChanged(_ => updateColour(), true);
+                Current.BindValueChanged(_ => updateColour(), true);
             }
 
             private void updateColour()
             {
-            fill.Colour = current.Value;
+                fill.Colour = Current.Value;
-            colourHexCode.Text = current.Value.ToHex();
+                colourHexCode.Text = Current.Value.ToHex();
-            colourHexCode.Colour = OsuColour.ForegroundTextColourFor(current.Value);
+                colourHexCode.Colour = OsuColour.ForegroundTextColourFor(Current.Value);
             }
 
             public Popover GetPopover() => new OsuPopover(false)
@@ -114,5 +137,11 @@ namespace osu.Game.Graphics.UserInterfaceV2
                     Current = { BindTarget = Current }
                 }
             };
+
+            public MenuItem[] ContextMenuItems => new MenuItem[]
+            {
+                new OsuMenuItem("Delete", MenuItemType.Destructive, () => DeleteRequested?.Invoke())
+            };
+        }
     }
 }

osu.Game/Graphics/UserInterfaceV2/ColourPalette.cs

@@ -92,6 +92,7 @@ namespace osu.Game.Graphics.UserInterfaceV2
                 });
 
                 display.Current.BindValueChanged(colour => Colours[colourIndex] = colour.NewValue);
+                display.DeleteRequested += colourDeletionRequested;
             }
 
             palette.Add(new AddColourButton
@@ -102,6 +103,8 @@ namespace osu.Game.Graphics.UserInterfaceV2
             reindexItems();
         }
 
+        private void colourDeletionRequested(ColourDisplay display) => Colours.RemoveAt(palette.IndexOf(display));
+
         private void reindexItems()
         {
             int index = 1;