EditorWindow to display PlayerLoop in Unity.

PlayerLoopViewer.cs

using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;
using UnityEngine.LowLevel;

namespace HassakuLab.Utils.PlayerLoops.Editor
{
    public class PlayerLoopViewer : EditorWindow
    {
        [MenuItem("HassakuLab/PlayerLoopViewer")]
        private static void ShowWindow()
        {
            var window = GetWindow<PlayerLoopViewer>();
            window.titleContent = new GUIContent("PlayerLoopViewer");
            window.Show();
        }

        private readonly Dictionary<Type, bool> isFoldOpenTable = new();
        private Vector2 scrollPosition;

        private void RenderSubsystemOnGui(PlayerLoopSystem system, int depth)
        {
            if (!isFoldOpenTable.ContainsKey(system.type))
            {
                isFoldOpenTable.Add(system.type, false);
            }
            EditorGUI.indentLevel = depth;
            isFoldOpenTable[system.type] = EditorGUILayout.Foldout(isFoldOpenTable[system.type],system.type.Name);
            if (isFoldOpenTable[system.type])
            {
                if (system.subSystemList != null)
                {
                    foreach (var subSystem in system.subSystemList)
                    {
                        RenderSubsystemOnGui(subSystem, depth+1);
                    }
                }
            }
        }

        private void OnGUI()
        {
            scrollPosition = EditorGUILayout.BeginScrollView(scrollPosition);
            if (EditorApplication.isPlaying)
            {
                PlayerLoopSystem playerLoop = PlayerLoop.GetCurrentPlayerLoop();
                foreach (var subSystem in playerLoop.subSystemList)
                {
                    RenderSubsystemOnGui(subSystem, 0);
                }
            }
            else
            {
                EditorGUILayout.LabelField("Move to PlayMode to display PlayerLoopSystem.");
            }
            EditorGUILayout.EndScrollView();
        }
    }
}