Utils/Editor/EventManagerEditor.cs

using System;
using UnityEditor;
using UnityEngine;

namespace Utils.Editor
{
    [CustomEditor(typeof(EventManager), true)]
    public class EventManagerEditor : UnityEditor.Editor
    {
        public override void OnInspectorGUI()
        {
            Event("EarlyUpdate", App.EarlyUpdateLength, App.EarlyUpdateDelegates);
            EditorGUILayout.Space();
            Event("Update", App.UpdateLength, App.UpdateDelegates);
            EditorGUILayout.Space();
            Event("LateUpdate", App.LateUpdateLength, App.LateUpdateDelegates);
            EditorGUILayout.Space();
            Event("LastUpdate", App.LastUpdateLength, App.LastUpdateDelegates);
        }

        private void Event(string title, int length, Delegate[] delegates)
        {
            {
                GUILayout.BeginHorizontal();

                GUILayout.Label(title, EditorStyles.boldLabel);
                GUILayout.FlexibleSpace();
                GUILayout.Label(length.ToString());

                GUILayout.EndHorizontal();

                if (length == 0) return;
                foreach (var d in delegates)
                {
                    GUILayout.Label($"{d.Method.DeclaringType}.{d.Method.Name}", EditorStyles.miniLabel);
                }
            }
        }
    }
}