SteamTools/System.Application.SteamTools.Client.Desktop/Extensions/PropertyChangedExtensions.cs

using StatefulModel.EventListeners;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace System.Application.Extensions
{
	public static class PropertyChangedExtensions
	{
		/// <summary>
		/// <see cref="INotifyPropertyChanged.PropertyChanged"/> 订阅事件
		/// </summary>
		public static IDisposable Subscribe(this INotifyPropertyChanged source, PropertyChangedEventHandler handler)
		{
			return new PropertyChangedEventListener(source, handler);
		}

		/// <summary>
		/// <see cref="INotifyPropertyChanged.PropertyChanged"/> 订阅事件
		/// </summary>
		/// <param name="source">イベント ソース。</param>
		/// <param name="action">イベント発生時に、<see cref="PropertyChangedEventArgs.PropertyName"/> を受け取って実行されるメソッド。</param>
		public static IDisposable Subscribe(this INotifyPropertyChanged source, Action<string> action)
		{
			return new PropertyChangedEventListener(source, (sender, args) => action(args.PropertyName));
		}

		/// <summary>
		/// 与指定的属性名称一起执行 <see cref="INotifyPropertyChanged.PropertyChanged"/> 订阅事件
		/// </summary>
		/// <param name="source">事件源</param>
		/// <param name="propertyName">订阅事件的属性的名称</param>
		/// <param name="action">事件发生时执行的方法</param>
		/// <param name="immediately">在调用此方法时 <paramref name="action"/> 如果只运行一次，则为true，否则为false，默认值是true。</param>
		public static ListenerWrapper Subscribe(this INotifyPropertyChanged source, string propertyName, Action action, bool immediately = true)
		{
			return new ListenerWrapper(source).Subscribe(propertyName, action, immediately);
		}

		public class ListenerWrapper : IDisposable
		{
			//用于一个事件源
			//当要订阅多个属性更改通知时
			// EventSource // <-INotifyPropertyChanged对象
			// .Subscribe（nameof（Property1），（）=> {...}）
			// .Subscribe（nameof（Property2），（）=> {...}）
			// .Subscribe（nameof（Property3），（）=> {...}）
			// .AddTo（this）;
			//仅出于编写目的而准备

			private readonly PropertyChangedEventListener _listener;

			internal ListenerWrapper(INotifyPropertyChanged source)
			{
				this._listener = new PropertyChangedEventListener(source);
			}

			/// <summary>
			/// 与指定的属性名称一起执行 <see cref="INotifyPropertyChanged.PropertyChanged"/> 订阅事件
			/// </summary>
			/// <param name="propertyName">订阅事件的属性的名称</param>
			/// <param name="action">事件发生时执行的方法。</param>
			/// <param name="immediately">在调用此方法时 <paramref name="action"/>  如果只运行一次，则为true，否则为false，默认值是true。</param>
			public ListenerWrapper Subscribe(string propertyName, Action action, bool immediately = true)
			{
				if (immediately) action();
				this._listener.Add(propertyName, (sender, args) => action());
				return this;
			}

			void IDisposable.Dispose() => this._listener.Dispose();
		}
	}
}