Move major barline portion to default implementation to allow for further customisation

Of note, this removes the "major" barline triangles from legacy skins. I
think this is more correct, as they did not display in stable.

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableBarLine.cs

@@ -1,17 +1,12 @@
 // 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.
 
-#nullable disable
-
-using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
-using osu.Framework.Graphics.Containers;
-using osu.Framework.Graphics.Shapes;
 using osu.Game.Rulesets.Objects;
-using osuTK;
 using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Skinning.Default;
 using osu.Game.Skinning;
 
 namespace osu.Game.Rulesets.Taiko.Objects.Drawables
@@ -28,35 +23,15 @@ namespace osu.Game.Rulesets.Taiko.Objects.Drawables
         /// </summary>
         private const float tracker_width = 2f;
 
-        /// <summary>
+        public readonly Bindable<bool> Major = new Bindable<bool>();
-        /// The vertical offset of the triangles from the line tracker.
-        /// </summary>
-        private const float triangle_offset = 10f;
-
-        /// <summary>
-        /// The size of the triangles.
-        /// </summary>
-        private const float triangle_size = 20f;
-
-        /// <summary>
-        /// The visual line tracker.
-        /// </summary>
-        private SkinnableDrawable line;
-
-        /// <summary>
-        /// Container with triangles. Only visible for major lines.
-        /// </summary>
-        private Container triangleContainer;
-
-        private readonly Bindable<bool> major = new Bindable<bool>();
 
         public DrawableBarLine()
             : this(null)
         {
         }
 
-        public DrawableBarLine([CanBeNull] BarLine barLine)
+        public DrawableBarLine(BarLine? barLine)
-            : base(barLine)
+            : base(barLine!)
         {
         }
 
@@ -69,69 +44,23 @@ namespace osu.Game.Rulesets.Taiko.Objects.Drawables
             RelativeSizeAxes = Axes.Y;
             Width = tracker_width;
 
-            AddRangeInternal(new Drawable[]
+            AddInternal(new SkinnableDrawable(new TaikoSkinComponent(TaikoSkinComponents.BarLine), _ => new DefaultBarLine())
             {
-                line = new SkinnableDrawable(new TaikoSkinComponent(TaikoSkinComponents.BarLine), _ => new Box
+                Anchor = Anchor.Centre,
-                {
+                Origin = Anchor.Centre,
-                    RelativeSizeAxes = Axes.Both,
-                    EdgeSmoothness = new Vector2(0.5f, 0),
-                })
-                {
-                    Anchor = Anchor.Centre,
-                    Origin = Anchor.Centre,
-                },
-                triangleContainer = new Container
-                {
-                    Anchor = Anchor.Centre,
-                    Origin = Anchor.Centre,
-                    RelativeSizeAxes = Axes.Both,
-                    Children = new[]
-                    {
-                        new EquilateralTriangle
-                        {
-                            Name = "Top",
-                            Anchor = Anchor.TopCentre,
-                            Origin = Anchor.TopCentre,
-                            Position = new Vector2(0, -triangle_offset),
-                            Size = new Vector2(-triangle_size),
-                            EdgeSmoothness = new Vector2(1),
-                        },
-                        new EquilateralTriangle
-                        {
-                            Name = "Bottom",
-                            Anchor = Anchor.BottomCentre,
-                            Origin = Anchor.TopCentre,
-                            Position = new Vector2(0, triangle_offset),
-                            Size = new Vector2(triangle_size),
-                            EdgeSmoothness = new Vector2(1),
-                        }
-                    }
-                }
             });
         }
 
-        protected override void LoadComplete()
-        {
-            base.LoadComplete();
-            major.BindValueChanged(updateMajor, true);
-        }
-
-        private void updateMajor(ValueChangedEvent<bool> major)
-        {
-            line.Alpha = major.NewValue ? 1f : 0.75f;
-            triangleContainer.Alpha = major.NewValue ? 1 : 0;
-        }
-
         protected override void OnApply()
         {
             base.OnApply();
-            major.BindTo(HitObject.MajorBindable);
+            Major.BindTo(HitObject.MajorBindable);
         }
 
         protected override void OnFree()
         {
             base.OnFree();
-            major.UnbindFrom(HitObject.MajorBindable);
+            Major.UnbindFrom(HitObject.MajorBindable);
         }
 
         protected override void UpdateHitStateTransforms(ArmedState state)

osu.Game.Rulesets.Taiko/Skinning/Default/DefaultBarLine.cs

@@ -0,0 +1,94 @@
+// 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 osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Objects.Drawables;
+using osuTK;
+
+namespace osu.Game.Rulesets.Taiko.Skinning.Default
+{
+    public class DefaultBarLine : CompositeDrawable
+    {
+        /// <summary>
+        /// The vertical offset of the triangles from the line tracker.
+        /// </summary>
+        private const float triangle_offset = 10f;
+
+        /// <summary>
+        /// The size of the triangles.
+        /// </summary>
+        private const float triangle_size = 20f;
+
+        /// <summary>
+        /// Container with triangles. Only visible for major lines.
+        /// </summary>
+        private Container triangleContainer = null!;
+
+        private Bindable<bool> major = null!;
+
+        [BackgroundDependencyLoader]
+        private void load(DrawableHitObject drawableHitObject)
+        {
+            RelativeSizeAxes = Axes.Both;
+
+            InternalChildren = new Drawable[]
+            {
+                line = new Box
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    EdgeSmoothness = new Vector2(0.5f, 0),
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                },
+                triangleContainer = new Container
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    RelativeSizeAxes = Axes.Both,
+                    Children = new[]
+                    {
+                        new EquilateralTriangle
+                        {
+                            Name = "Top",
+                            Anchor = Anchor.TopCentre,
+                            Origin = Anchor.TopCentre,
+                            Position = new Vector2(0, -triangle_offset),
+                            Size = new Vector2(-triangle_size),
+                            EdgeSmoothness = new Vector2(1),
+                        },
+                        new EquilateralTriangle
+                        {
+                            Name = "Bottom",
+                            Anchor = Anchor.BottomCentre,
+                            Origin = Anchor.TopCentre,
+                            Position = new Vector2(0, triangle_offset),
+                            Size = new Vector2(triangle_size),
+                            EdgeSmoothness = new Vector2(1),
+                        }
+                    }
+                }
+            };
+
+            major = ((DrawableBarLine)drawableHitObject).Major.GetBoundCopy();
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+            major.BindValueChanged(updateMajor, true);
+        }
+
+        private Box line = null!;
+
+        private void updateMajor(ValueChangedEvent<bool> major)
+        {
+            line.Alpha = major.NewValue ? 1f : 0.75f;
+            triangleContainer.Alpha = major.NewValue ? 1 : 0;
+        }
+    }
+}

osu.Game/Rulesets/Objects/Drawables/DrawableHitObject.cs

@@ -736,7 +736,7 @@ namespace osu.Game.Rulesets.Objects.Drawables
     {
         public new TObject HitObject => (TObject)base.HitObject;
 
-        protected DrawableHitObject(TObject hitObject)
+        protected DrawableHitObject([CanBeNull] TObject hitObject)
             : base(hitObject)
         {
         }