Unity UI EventTrigger instance

UIEventListener.cs

using UnityEngine;
using UnityEngine.EventSystems;

public class UIEventListener : EventTrigger
{
    public delegate void UIDelegate(GameObject go);
    public delegate void UIDragDelegate(Vector2 pressionPosition);

    public event UIDelegate onPointerEnter;
    public event UIDelegate onPointerExit;
    public event UIDelegate onPointerDown;
    public event UIDelegate onPointerUp;
    public event UIDelegate onPointerClick;
    public event UIDelegate onInitializePotentialDrag;
    public event UIDelegate onBeginDrag;
    public event UIDelegate onDrag;
    public event UIDelegate onEndDrag;
    public event UIDelegate onDrop;
    public event UIDelegate onScroll;
    public event UIDelegate onUpdateSelected;
    public event UIDelegate onSelect;
    public event UIDelegate onDeselect;
    public event UIDelegate onMove;
    public event UIDelegate onSubmit;
    public event UIDelegate onCancel;

    public event UIDragDelegate onBeginDragEx;
    public event UIDragDelegate onDragEx;
    public event UIDragDelegate onEndDragEx;

    public static UIEventListener GetListener(GameObject go)
    {
        UIEventListener listener = go.GetComponent<UIEventListener>();

        if (null == listener)
        {
            listener = go.AddComponent<UIEventListener>();
        }

        return listener;
    }

    public override void OnPointerEnter(PointerEventData eventData)
    {
        if (null != onPointerEnter)
        {
            onPointerEnter(gameObject);
        }
    }

    public override void OnPointerExit(PointerEventData eventData)
    {
        if (null != onPointerExit)
        {
            onPointerExit(gameObject);
        }
    }

    public override void OnPointerDown(PointerEventData eventData)
    {
        if (null != onPointerDown)
        {
            onPointerDown(gameObject);
        }
    }

    public override void OnPointerUp(PointerEventData eventData)
    {
        if (null != onPointerUp)
        {
            onPointerUp(gameObject);
        }
    }

    public override void OnPointerClick(PointerEventData eventData)
    {
        if (null != onPointerClick)
        {
            onPointerClick(gameObject);
        }
    }

    public override void OnInitializePotentialDrag(PointerEventData eventData)
    {
        if (null != onInitializePotentialDrag)
        {
            onInitializePotentialDrag(gameObject);
        }
    }

    public override void OnBeginDrag(PointerEventData eventData)
    {
        if (null != onBeginDrag)
        {
            onBeginDrag(gameObject);
        }

        if (null != onBeginDragEx)
        {
            onBeginDragEx(eventData.position);
        }
    }

    public override void OnDrag(PointerEventData eventData)
    {
        if (null != onDrag)
        {
            onDrag(gameObject);
        }

        if (null != onDragEx)
        {
            onDragEx(eventData.position);
        }
    }

    public override void OnEndDrag(PointerEventData eventData)
    {
        if (null != onEndDrag)
        {
            onEndDrag(gameObject);
        }

        if (null != onEndDragEx)
        {
            onEndDragEx(eventData.position);
        }
    }

    public override void OnDrop(PointerEventData eventData)
    {
        if (null != onDrop)
        {
            onDrop(gameObject);
        }
    }

    public override void OnScroll(PointerEventData eventData)
    {
        if (null != onScroll)
        {
            onScroll(gameObject);
        }
    }

    public override void OnUpdateSelected(BaseEventData eventData)
    {
        if (null != onUpdateSelected)
        {
            onUpdateSelected(gameObject);
        }
    }

    public override void OnSelect(BaseEventData eventData)
    {
        if (null != onSelect)
        {
            onSelect(gameObject);
        }
    }

    public override void OnDeselect(BaseEventData eventData)
    {
        if (null != onDeselect)
        {
            onDeselect(gameObject);
        }
    }

    public override void OnMove(AxisEventData eventData)
    {
        if (null != onMove)
        {
            onMove(gameObject);
        }
    }

    public override void OnSubmit(BaseEventData eventData)
    {
        if (null != onSubmit)
        {
            onSubmit(gameObject);
        }
    }

    public override void OnCancel(BaseEventData eventData)
    {
        if (null != onCancel)
        {
            onCancel(gameObject);
        }
    }
}