spacerace/Assets/Src/UI/InterfaceIcon.cs

using System.Collections;
using System.Collections.Generic;

using UnityEngine;
using UnityEngine.UIElements;

public class InterfaceIcon : VisualElement {
    public enum Icon {
        // Outputs
        Acceleration,
        Deceleration,
        Strafe,
        Shield,

        Crosshair,

        Logo,
    }

    public new class UxmlFactory : UxmlFactory<InterfaceIcon, UxmlTraits> {}
    public new class UxmlTraits : VisualElement.UxmlTraits {
        readonly UxmlEnumAttributeDescription<Icon> _iconAttribute = new() { name = "icon" };
        readonly UxmlStringAttributeDescription _detailAttribute = new UxmlStringAttributeDescription() { name = "detail" };

        public override void Init(VisualElement ve, IUxmlAttributes bag, CreationContext cc) {
            base.Init(ve, bag, cc);
            var InterfaceIcon = (InterfaceIcon)ve;
            InterfaceIcon.icon = _iconAttribute.GetValueFromBag(bag, cc);
            InterfaceIcon.detail = _detailAttribute.GetValueFromBag(bag, cc);
        }
    }

    static readonly Dictionary<Icon, char> _iconGlyphMap = new() {
        { Icon.Acceleration,    '\u25bc' },
        { Icon.Deceleration,    '\u25b2' },
        { Icon.Strafe,          '\u2b94' },
        { Icon.Shield,          '\u26c9' },

        { Icon.Logo,    '\u26d0' },
    };

    public Icon icon {
        get => _icon;
        set {
            _icon = value;
            _iconLabel.text = _iconGlyphMap[value].ToString();
        }
    }

    public string detail {
        get => _detail;
        set {
            _detail = value;
            _detailLabel.text = value;
        }
    }

    Icon _icon;
    string _detail;

    Label _iconLabel;
    Label _detailLabel;

    public InterfaceIcon() : this(Icon.Strafe) {}

    public InterfaceIcon(Icon icon) {
        _iconLabel = new Label {
            style = {
                unityFont = Resources.Load<Font>("SpaceRace-Icons"),
                unityFontDefinition = StyleKeyword.None,
            },
        };

        Add(_iconLabel);

        _detailLabel = new Label {
            style = {
                position = Position.Absolute,
            },
        };

        _detailLabel.AddToClassList("detail");

        Add(_detailLabel);

        this.icon = icon;
    }
}