Add legacy implementation

osu.Game/Skinning/LegacyHealthDisplay.cs

@@ -0,0 +1,101 @@
+// 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.Sprites;
+using osu.Game.Rulesets.Judgements;
+using osu.Game.Screens.Play.HUD;
+using osuTK;
+
+namespace osu.Game.Skinning
+{
+    public class LegacyHealthDisplay : CompositeDrawable, IHealthDisplay
+    {
+        private readonly Skin skin;
+        private Sprite fill;
+        private Marker marker;
+        public Bindable<double> Current { get; } = new BindableDouble { MinValue = 0, MaxValue = 1 };
+
+        public LegacyHealthDisplay(Skin skin)
+        {
+            this.skin = skin;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            AutoSizeAxes = Axes.Both;
+
+            InternalChildren = new Drawable[]
+            {
+                new Sprite
+                {
+                    Texture = skin.GetTexture("scorebar-bg")
+                },
+                fill = new Sprite
+                {
+                    Texture = skin.GetTexture("scorebar-colour"),
+                    Position = new Vector2(7.5f, 7.8f) * 1.6f
+                },
+                marker = new Marker(skin)
+                {
+                    Current = { BindTarget = Current },
+                }
+            };
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            Current.BindValueChanged(updateHp, true);
+        }
+
+        private void updateHp(ValueChangedEvent<double> hp)
+        {
+            if (fill.Texture != null)
+                fill.ResizeWidthTo((float)(fill.Texture.DisplayWidth * hp.NewValue), 500, Easing.OutQuint);
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            marker.Position = fill.Position + new Vector2(fill.DrawWidth, fill.DrawHeight / 2);
+        }
+
+        public void Flash(JudgementResult result)
+        {
+            marker.ScaleTo(1.4f).Then().ScaleTo(1, 200, Easing.Out);
+        }
+
+        private class Marker : CompositeDrawable
+        {
+            public Bindable<double> Current { get; } = new Bindable<double>();
+
+            public Marker(Skin skin)
+            {
+                Origin = Anchor.Centre;
+
+                if (skin.GetTexture("scorebar-ki") != null)
+                {
+                    // TODO: old style (marker changes as health decreases)
+                }
+                else
+                {
+                    InternalChildren = new Drawable[]
+                    {
+                        new Sprite
+                        {
+                            Texture = skin.GetTexture("scorebar-marker"),
+                            Origin = Anchor.Centre,
+                        }
+                    };
+                }
+            }
+        }
+    }
+}

osu.Game/Skinning/LegacySkin.cs

@@ -347,6 +347,9 @@ namespace osu.Game.Skinning
 
                         case HUDSkinComponents.AccuracyCounter:
                             return new LegacyAccuracyCounter(this);
+
+                        case HUDSkinComponents.HealthDisplay:
+                            return new LegacyHealthDisplay(this);
                     }
 
                     return null;