//--------------------------------------------------------
//    [Author]:           玩个游戏
//    [  Date ]:           Saturday, November 25, 2017
//--------------------------------------------------------
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using System.Collections.Generic;
using System;


    [RequireComponent(typeof(RectTransform))]
    public class FakeButton : MonoBehaviour, IPointerClickHandler, IPointerDownHandler, IPointerUpHandler, IDragHandler
    {
        RectTransform m_RectTransform;
        public RectTransform rectTransform { get { return m_RectTransform ?? (m_RectTransform = this.transform as RectTransform); } }

        Action m_OnClick;

        public void AddListener(Action action)
        {
            m_OnClick += action;
        }

        public void RemoveAllListeners()
        {
            m_OnClick = null;
        }

        public void OnPointerUp(PointerEventData eventData)
        {
            PassEvent(eventData, ExecuteEvents.pointerUpHandler);
        }

        public void OnPointerDown(PointerEventData eventData)
        {
            PassEvent(eventData, ExecuteEvents.pointerDownHandler);
        }

        public void OnDrag(PointerEventData eventData)
        {
            PassEvent(eventData, ExecuteEvents.dragHandler);
        }

        public void OnPointerClick(PointerEventData eventData)
        {
            m_OnClick?.Invoke();
            PassEvent(eventData, ExecuteEvents.submitHandler);
            PassEvent(eventData, ExecuteEvents.pointerClickHandler);
        }

        public void PassEvent<T>(PointerEventData data, ExecuteEvents.EventFunction<T> function) where T : IEventSystemHandler
        {
            List<RaycastResult> results = new List<RaycastResult>();
            EventSystem.current.RaycastAll(data, results);
            GameObject current = data.pointerCurrentRaycast.gameObject;
            for (int i = 0; i < results.Count; i++)
            {
                if (current != results[i].gameObject)
                {
                    if (ExecuteEvents.Execute(results[i].gameObject, data, function))
                    {
                        break;
                    }
                }
            }
        }


    }