A reflection based class inspector/editor for StereoKit

Inspector.cs

using System;
using System.Linq;
using System.Reflection;

namespace StereoKit.Framework
{

	///////////////////////////////////////////

	abstract class InspectorAttribute : Attribute
	{
		public abstract void Show(PropertyInfo prop, object inst);
	}

	///////////////////////////////////////////

	class SliderAttribute : InspectorAttribute
	{
		public float min, max, step;
		public SliderAttribute(float min, float max, float step = 0)
		{
			this.min  = min;
			this.max  = max;
			this.step = step;
		}

		public override void Show(PropertyInfo prop, object inst)
		{
			if (prop.PropertyType == typeof(float))
			{
				float val = (float)prop.GetValue(inst);
				if (UI.HSlider(prop.Name, ref val, min, max, step, 0, UIConfirm.Pinch))
					prop.SetValue(inst, val);
			}
			else if (prop.PropertyType == typeof(int))
			{
				float val = (float)(int)prop.GetValue(inst);
				if (UI.HSlider(prop.Name, ref val, min, max, step, 0, UIConfirm.Pinch))
					prop.SetValue(inst, (int)val);
			}
		}
	}

	///////////////////////////////////////////

	class BrowseAttribute : InspectorAttribute
	{
		public string[] filters;
		public BrowseAttribute(params string[] filters)
		{
			this.filters = filters;
		}

		public override void Show(PropertyInfo prop, object inst)
		{
			string val = (string)prop.GetValue(inst);
			if (UI.Button("Browse"))
			{
				Platform.FilePicker(PickerMode.Open, (s) =>
				{
					prop.SetValue(inst, s);
				}, null, filters);
			}
			UI.SameLine();
			UI.Label(val, V.XY(UI.LayoutRemaining.x-0.02f, 0));
		}
	}

	///////////////////////////////////////////

	class Inspector
	{
		struct PropertyItem
		{
			public PropertyInfo       prop;
			public InspectorAttribute attribute;
		}

		object         item;
		Type           itemType;
		PropertyItem[] properties;

		public object Item { get => item; }

		public Inspector() { }
		public Inspector(object item) { SetObject(item); }

		private bool ValidType(Type type)
		{
			return type == typeof(int) 
				|| type == typeof(float);
		}

		public void SetObject(object newItem)
		{
			item       = newItem;
			itemType   = newItem.GetType();
			properties = itemType
				.GetProperties()
				.Where (p => p.GetCustomAttribute<InspectorAttribute>() != null || ValidType(p.PropertyType))
				.Select(p => new PropertyItem
				{
					prop      = p,
					attribute = p.GetCustomAttribute<InspectorAttribute>()
				})
				.ToArray();
		}

		public void DrawUI()
		{
			int curr = 1;
			foreach (PropertyItem p in properties)
			{
				UI.PushId(curr++);
				UI.Label(p.prop.Name, new Vec2(0.06f, 0));
				UI.SameLine();
				if (p.attribute != null) { p.attribute.Show(p.prop, item); }
				else
				{
					switch (p.prop.GetValue(item))
					{
						case string val: if (UI.Input(p.prop.Name, ref val)) { p.prop.SetValue(item, val); } break;
						case int    val:
							{
								if (UI.Button("-")) { val -= 1; p.prop.SetValue(item, val); }
								UI.SameLine();
								UI.Label(val.ToString());
								UI.SameLine();
								if (UI.Button("+")) { val += 1; p.prop.SetValue(item, val); }
							}
							break;
					}
				}
				UI.PopId();
			}
		}
	}

	///////////////////////////////////////////

	class InspectorWindow : IStepper
	{
		static InspectorWindow instance = null;
		public static void Show(object item)
		{
			if (instance == null) instance = new InspectorWindow();

			instance.inspector = new Inspector(item);
			instance.pose      = new Pose(Input.Head.position + Input.Head.Forward * 0.35f, Quat.FromAngles(0, 180, 0) * Input.Head.orientation);

			PropertyInfo info = item.GetType().GetProperty("Name");
			instance.name = info != null
				? info.GetValue(item).ToString()
				: item.GetType().Name;
			SK.AddStepper(instance);
		}
		public static void Hide()
		{
			SK.RemoveStepper(instance);
			instance.inspector = null;
		}

		string    name;
		Pose      pose;
		Inspector inspector;
		public Action<object> OnDelete;
		public bool Enabled => true;

		public InspectorWindow()
		{
			instance = this;
		}
		public InspectorWindow(Action<object> onDelete)
		{
			instance = this;
			OnDelete = onDelete;
		}

		public bool Initialize() => true;

		public void Shutdown() { }

		public void Step()
		{
			if (!Enabled) return;

			UI.WindowBegin(name, ref pose, V.XY(.3f,0));

			inspector.DrawUI();

			UI.HSeparator();

			if (UI.Button("Close"))
				Hide();

			if (OnDelete != null)
			{
				UI.SameLine();
				UI.PushTint(new(1,0,0,1));
				if (UI.Button("Delete"))
				{
					OnDelete(inspector.Item);
					Hide();
				}
				UI.PopTint();
			}

			UI.WindowEnd();
		}
	}

}