Unity C# click and longPress

guiScript

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;

public class uGuiScript : MonoBehaviour, IPointerDownHandler, IPointerUpHandler {

    public UnityEvent onLongPress = new UnityEvent();
    public UnityEvent onClick = new UnityEvent();

    [SerializeField]
    private float longPressed;
    [SerializeField]
    private float diff;

    private bool flgLongPressed = false;
    private float timeElasped;

    private Vector3 startPos;
    private Vector3 nowPos;
    private Vector3 endPos;

    public bool pressed {
        get;
        private set;
    }
    
    void Update() {
        nowPos = Input.mousePosition;

        if(pressed) {
            timeElasped += Time.deltaTime;
        }

        if (Mathf.Abs(startPos.x - nowPos.x) >= diff || Mathf.Abs(startPos.y - nowPos.y) >= diff) {
            InitCount();
            return;
        }

        if (longPressed < timeElasped && pressed == true) {
            flgLongPressed = true;

            onLongPress.Invoke();

            InitCount();
        }
    }

    public void OnPointerDown(PointerEventData eventData) {
        startPos = eventData.position;
        pressed = true;
    }

    public void OnPointerUp(PointerEventData eventData) {
        endPos = eventData.position;

        if(Mathf.Abs(startPos.x - endPos.x) >= diff || Mathf.Abs(startPos.y - endPos.y) >= diff) {
            return;
        }

        if (flgLongPressed) {
            flgLongPressed = false;
        }else { 
            onClick.Invoke();
        }

        InitCount();

    }

    private void InitCount() {
        pressed = false;
        timeElasped = 0f;
    }
}