using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.Events;
using UnityEngine.UI;

namespace UIWidgets
{
	[RequireComponent(typeof(ScrollRect))]
	public class ScrollRectEvents : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler, IEventSystemHandler
	{
		[SerializeField]
		public float RequiredMovement = 50f;

		[SerializeField]
		public UnityEvent OnPullUp = new UnityEvent();

		[SerializeField]
		public UnityEvent OnPullDown = new UnityEvent();

		[SerializeField]
		public UnityEvent OnPullLeft = new UnityEvent();

		[SerializeField]
		public UnityEvent OnPullRight = new UnityEvent();

		private ScrollRect scrollRect;

		private bool initedPullUp;

		private bool initedPullDown;

		private bool initedPullLeft;

		private bool initedPullRight;

		private float MovementUp;

		private float MovementDown;

		private float MovementLeft;

		private float MovementRight;

		public ScrollRect ScrollRect
		{
			get
			{
				if (scrollRect == null)
				{
					scrollRect = GetComponent<ScrollRect>();
				}
				return scrollRect;
			}
		}

		public virtual void OnBeginDrag(PointerEventData eventData)
		{
			initedPullUp = false;
			initedPullDown = false;
			initedPullLeft = false;
			initedPullRight = false;
			MovementUp = 0f;
			MovementDown = 0f;
			MovementLeft = 0f;
			MovementRight = 0f;
		}

		public virtual void OnEndDrag(PointerEventData eventData)
		{
			initedPullUp = false;
			initedPullDown = false;
			initedPullLeft = false;
			initedPullRight = false;
			MovementUp = 0f;
			MovementDown = 0f;
			MovementLeft = 0f;
			MovementRight = 0f;
		}

		public virtual void OnDrag(PointerEventData eventData)
		{
			RectTransform rectTransform = ScrollRect.transform as RectTransform;
			float height = rectTransform.rect.height;
			float width = rectTransform.rect.width;
			float num = Mathf.Max(0f, ScrollRect.content.rect.height - height);
			float num2 = Mathf.Max(0f, ScrollRect.content.rect.width - width);
			if (ScrollRect.content.anchoredPosition.y <= 0f && !initedPullUp)
			{
				MovementUp += 0f - eventData.delta.y;
				if (MovementUp >= RequiredMovement)
				{
					initedPullUp = true;
					OnPullUp.Invoke();
				}
			}
			if (ScrollRect.content.anchoredPosition.y >= num && !initedPullDown)
			{
				MovementDown += eventData.delta.y;
				if (MovementDown >= RequiredMovement)
				{
					initedPullDown = true;
					OnPullDown.Invoke();
				}
			}
			if (ScrollRect.content.anchoredPosition.x <= 0f && !initedPullLeft)
			{
				MovementLeft += 0f - eventData.delta.x;
				if (MovementLeft >= RequiredMovement)
				{
					initedPullLeft = true;
					OnPullLeft.Invoke();
				}
			}
			if (ScrollRect.content.anchoredPosition.x >= num2 && !initedPullRight)
			{
				MovementRight += eventData.delta.x;
				if (MovementRight >= RequiredMovement)
				{
					initedPullRight = true;
					OnPullRight.Invoke();
				}
			}
		}
	}
}