LivesValueChanger

using System.Collections;
using UnityEngine;
using UnityEngine.UI;

public enum ButtonType
{ Heal, Damage }

public class LivesValueChanger : MonoBehaviour
{
    [SerializeField] private ButtonType _buttonType;
    [SerializeField] private Slider _slider;

    [Space]
    [SerializeField] private float _targetDelta;
    [SerializeField] private float _changeSpeed;

    private void OnValidate()
    {
        _targetDelta = Mathf.Abs(_targetDelta);
        _changeSpeed = Mathf.Abs(_changeSpeed);
    }

    private void Start()
    {

        switch (_buttonType)
        {
            default:
            case ButtonType.Heal:
                _changeSpeed = +Mathf.Abs(_changeSpeed);
                break;
            case ButtonType.Damage:
                _changeSpeed = -Mathf.Abs(_changeSpeed);
                break;
        }

    }

    private IEnumerator SmoothChange()
    {
        var tempValue = _slider.value;

        while (Mathf.Abs(_slider.value - tempValue) < _targetDelta)
        {
            _slider.value = Mathf.MoveTowards(_slider.value, _slider.value + _targetDelta, _changeSpeed * Time.deltaTime);
            yield return null;
        }
    }

    public void TryApplyAction()
    {
        if (_slider.value < _slider.minValue)
            _slider.value = _slider.minValue;
        else if (_slider.value > _slider.maxValue)
            _slider.value = _slider.maxValue;
        else
            StartCoroutine(SmoothChange());
    }
}