DrawableExtensions.cs

using System.Runtime.CompilerServices;

using osu.Framework.Graphics;

namespace ProjectHarmony.Game.Extensions;
public static class DrawableExtensions
{
    private static readonly ConditionalWeakTable<Drawable, DrawableExtensionProperties> Properties = [];
    extension(Drawable el)
    {
        
        public string ClassName
        { 
            get => Properties.GetOrCreateValue(el).ClassName;
            set => Properties.GetOrCreateValue(el).ClassName = value;
        }

        public string[] Classes 
        { 
            get => el.ClassName.Split(' ');
            set => el.ClassName = string.Join(' ', value);
        }
    }
    public class DrawableExtensionProperties
    {
        public string ClassName { get; set; } = string.Empty;
        public string[] Classes
        {
            get => ClassName.Split(' ');
            set => ClassName = string.Join(' ', value);
        }
    }
}