beyond/Assets/Scripts/UI/PopupMenuController.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using DG.Tweening;
using System;

namespace Beyond
{
    public class PopupMenuController : MonoBehaviour
    {
        private float fadeDuration = 0.6f, stayDuration = 2f;

        public TMPro.TMP_Text textField;
        private bool showing = false;
        private List<string> waitingMessages = new();

        public MenuScroll menuScroll;

        public static PopupMenuController Instance { get; private set; }

        private void Awake()
        {
            if (Instance != null && Instance != this)
            {
                Destroy(this);
            }
            else
            {
                Instance = this;
            }
            textField.alpha = 0;
            menuScroll.OnOpened += ClearPopup;
            menuScroll.OnClosed += ClearPopup;
            menuScroll.OnNewCanvaBurnMiddle += ClearPopup;
        }

        public void TryToShowPopupMesssage(string message)
        {
            if (!isActiveAndEnabled)
            {
                return;
            }
            if (showing)
            {
                waitingMessages.Add(message);
                return;
            }
            ShowPopupMessage(message);
        }

        private void ShowPopupMessage(string message)
        {
            showing = true;
            textField.alpha = 0f;
            textField.text = message;
            StartCoroutine(FadeOutCoroutine());
        }

        private IEnumerator FadeOutCoroutine()
        {
            while (textField.alpha < 1)
            {
                textField.alpha += Time.unscaledDeltaTime / fadeDuration;
                yield return new WaitForSecondsRealtime(Time.unscaledDeltaTime);
            }
            yield return new WaitForSecondsRealtime(stayDuration);
            while (textField.alpha > 0)
            {
                textField.alpha -= Time.unscaledDeltaTime / fadeDuration;
                yield return new WaitForSecondsRealtime(Time.unscaledDeltaTime * fadeDuration);
            }

            if (waitingMessages.Count > 0)
            {
                ShowPopupMessage(waitingMessages[0]);
                waitingMessages.RemoveAt(0);
            }
            else
            {
                showing = false;
            }
        }

        private void OnDestroy()
        {
            if (menuScroll)
            {
                menuScroll.OnOpened -= ClearPopup;
                menuScroll.OnClosed -= ClearPopup;
                menuScroll.OnNewCanvaBurnMiddle -= ClearPopup;
            }
        }

        private void ClearPopup()
        {
            StopAllCoroutines();
            textField.alpha = 0;
            showing = false;
            waitingMessages.Clear();
        }
    }
}