Custom UI Bar

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

[RequireComponent(typeof(Image))]
public class UIBarControl : MonoBehaviour, IDragHandler
{
    private float newLocalY;
    [SerializeField] private Canvas canvas;
    private Vector2 canvasPosition;
    [SerializeField] private RectTransform parentRectContainer;

    private float minY;
    private float maxY;

    public void OnDrag(PointerEventData eventData)
    {
        float oldPositionX = transform.position.x;

        MoveToCursorPosition();
        ClampLocalPosition(oldPositionX);
    }

    private void MoveToCursorPosition()
    {
        RectTransformUtility.ScreenPointToLocalPointInRectangle(canvas.transform as RectTransform,
                                                                Input.mousePosition, canvas.worldCamera, out canvasPosition);
        transform.position = canvas.transform.TransformPoint(canvasPosition);
    }

    private void ClampLocalPosition(float oldPositionX)
    {
        newLocalY = transform.position.y;

        minY = parentRectContainer.transform.position.y + parentRectContainer.offsetMin.y;
        maxY = parentRectContainer.transform.position.y + parentRectContainer.offsetMax.y;

        newLocalY = Mathf.Clamp(newLocalY, minY, maxY);
        transform.position = new Vector3(oldPositionX, newLocalY, transform.localPosition.z);
    }
}