Add taiko barline skinning support

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

@@ -6,6 +6,7 @@ using osu.Framework.Graphics.Shapes;
 using osu.Game.Rulesets.Objects;
 using osuTK;
 using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Skinning;
 
 namespace osu.Game.Rulesets.Taiko.Objects.Drawables
 {
@@ -27,7 +28,7 @@ namespace osu.Game.Rulesets.Taiko.Objects.Drawables
         /// <summary>
         /// The visual line tracker.
         /// </summary>
-        protected Box Tracker;
+        protected SkinnableDrawable Line;
 
         /// <summary>
         /// The bar line.
@@ -45,13 +46,15 @@ namespace osu.Game.Rulesets.Taiko.Objects.Drawables
             RelativeSizeAxes = Axes.Y;
             Width = tracker_width;
 
-            AddInternal(Tracker = new Box
+            AddInternal(Line = new SkinnableDrawable(new TaikoSkinComponent(TaikoSkinComponents.BarLine), _ => new Box
+            {
+                RelativeSizeAxes = Axes.Both,
+                EdgeSmoothness = new Vector2(0.5f, 0),
+            })
             {
                 Anchor = Anchor.Centre,
                 Origin = Anchor.Centre,
-                RelativeSizeAxes = Axes.Both,
+                Alpha = 0.75f,
-                EdgeSmoothness = new Vector2(0.5f, 0),
-                Alpha = 0.75f
             });
         }
 

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

@@ -53,7 +53,7 @@ namespace osu.Game.Rulesets.Taiko.Objects.Drawables
                 }
             });
 
-            Tracker.Alpha = 1f;
+            Line.Alpha = 1f;
         }
 
         protected override void LoadComplete()

osu.Game.Rulesets.Taiko/Skinning/LegacyBarLine.cs

@@ -0,0 +1,27 @@
+// 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.Graphics;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Skinning;
+using osuTK;
+
+namespace osu.Game.Rulesets.Taiko.Skinning
+{
+    public class LegacyBarLine : Sprite
+    {
+        [BackgroundDependencyLoader]
+        private void load(ISkinSource skin)
+        {
+            Texture = skin.GetTexture("taiko-barline");
+
+            Anchor = Anchor.Centre;
+            Origin = Anchor.Centre;
+
+            RelativeSizeAxes = Axes.Both;
+            Size = new Vector2(1, 0.88f);
+            FillMode = FillMode.Fill;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Skinning/TaikoLegacySkinTransformer.cs

@@ -75,6 +75,12 @@ namespace osu.Game.Rulesets.Taiko.Skinning
                         return Drawable.Empty();
 
                     return null;
+
+                case TaikoSkinComponents.BarLine:
+                    if (GetTexture("taiko-barline") != null)
+                        return new LegacyBarLine();
+
+                    return null;
             }
 
             return source.GetDrawableComponent(component);

osu.Game.Rulesets.Taiko/TaikoSkinComponents.cs

@@ -13,6 +13,7 @@ namespace osu.Game.Rulesets.Taiko
         Swell,
         HitTarget,
         PlayfieldBackgroundLeft,
-        PlayfieldBackgroundRight
+        PlayfieldBackgroundRight,
+        BarLine
     }
 }