Long Press Button issue on moving mouse

Unity Engine
1

Hi everyone

I use a long press button, which works very well, on MouseDown and if I don’t move the mouse, at the end of my delay, I have my action.
If I move the mouse (still pressing down and still on the button) it resets my button’s delay, and I don’t understand why.
if anyone has an idea, it would help me a lot.
Thx

Here’s my code :

private bool _PointerDown;
public float DelaiReponse;
private float _PointerDownTimer;
private bool _IsValidate = false;
private float _Delai;

    public void OnPointerDown(PointerEventData eventData)
    {
        _PointerDown = true;
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        _PointerDown = false;
        _PointerDownTimer = 0;
    }

    void Start()
    {
       _Delai = DelaiReponse;
    }

    private void Update()
    {
        if (_PointerDown) // Timer Button Validation Hold
        {
            _PointerDownTimer += Time.deltaTime;
            if (_PointerDownTimer >= _Delai)
            {
                _IsValidate = true;
            }
        }
    }
2

Find out
Just add IDragHandler to my class,
a bool _PointerDrag
and for my test in Update,

private void Update()
    {
        if (_PointerDown || _PointerDrag) // Timer Button Validation Hold
        {
            _PointerDownTimer += Time.deltaTime;
            if (_PointerDownTimer >= _Delai)
            {
                _IsValidate = true;
            }
        }