Net.Like.Xue.Tokyo/Assets/BITKit/Unity/Scripts/UX/SnackBar/UXSnackBar.cs

using System;
using System.Collections;
using System.Collections.Generic;
using BITKit;
using BITKit.Tween;
using BITKit.UX;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.UIElements;

namespace Net.BITKit.UX.SnackBar
{
    public static class UXSnackBarStatic
    {
        public static int Count;
    }
    public class UXSnackBar<TPanel> : UIToolkitSubPanel<TPanel>,IDisposable,ISnackBar where TPanel :IUXPanel
    {
        [UXBindPath("snack_bar-container")] private VisualElement _snackBarContainer;

        private VisualTreeAsset _template;
        
        private readonly ValidHandle _waitHandle = new ValidHandle();
        
        private readonly Queue<(string message,Severity severity)> _queue=new();

        public UXSnackBar(IServiceProvider serviceProvider) : base(serviceProvider)
        {
            if (UXSnackBarStatic.Count > 0)
            {
                throw new Exception("SnackBar can only be created once");
            }
            UXSnackBarStatic.Count++;
        }

        protected override void OnInitiated()
        {
            base.OnInitiated();
            _template = _snackBarContainer.Q<TemplateContainer>().templateSource;
            
            _snackBarContainer.Clear();
            
            BITAppForUnity.AllowCursor.AddListener(OnAllowCursor);

            while (_queue.TryDequeue(out var temp ))
            {
                Add(temp.message,temp.severity);
            }
        }

        private void OnAllowCursor(bool obj)
        {
            if (obj)
            {
                _waitHandle.AddElement(this);
            }
            else
            {
                _waitHandle.RemoveElement(this);
            }
        }

        public void Add(string message, Severity severity = Severity.Normal)
        {
            if (_snackBarContainer is null)
            {
                _queue.Enqueue(new ValueTuple<string, Severity>(message,severity));
                return;
            }
            
            var ve = _snackBarContainer.Create(_template);
            
            ve.AddToClassList($"severity-{severity.ToString().ToLower()}");

            ve.Get<Label>().text = message;

            Continue();

            return;
            async void Continue()
            {
                if (ve.Q("VisualElement--1") is { } bar)
                {
                    await BITween.Lerp(x => bar.style.width = new StyleLength(Length.Percent(x)), 0f, 100, 5, Mathf.Lerp);
                }
                else
                {
                    await UniTask.Delay(5000);
                }

                await _waitHandle;
            
                ve.RemoveFromHierarchy();
            }
        }

        public void Dispose()
        {
            UXSnackBarStatic.Count--;
        }
    }

}