GlobalApplicationEvent.cs

using System;
using UnityEngine;

namespace Kogane
{
    [AddComponentMenu( "" )]
    [DisallowMultipleComponent]
    public sealed class GlobalApplicationEvent : MonoBehaviour
    {
        public static Action<bool> OnPause { get; set; }
        public static Action<bool> OnFocus { get; set; }
        public static Action       OnQuit  { get; set; }

        private void OnApplicationPause( bool pauseStatus )
        {
            OnPause?.Invoke( pauseStatus );
        }

        private void OnApplicationFocus( bool hasFocus )
        {
            OnFocus?.Invoke( hasFocus );
        }

        private void OnApplicationQuit()
        {
            OnQuit?.Invoke();
        }

        [RuntimeInitializeOnLoadMethod( RuntimeInitializeLoadType.BeforeSceneLoad )]
        private static void RuntimeInitializeOnLoadMethod()
        {
            if ( FindObjectOfType<GlobalApplicationEvent>() != null ) return;

            var gameObject = new GameObject( nameof( GlobalApplicationEvent ) );
            gameObject.AddComponent<GlobalApplicationEvent>();
            //gameObject.hideFlags = HideFlags.HideAndDontSave;
            DontDestroyOnLoad( gameObject );
        }
    }
}