Panel move (child control)

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

namespace UI_controls {
    [RequireComponent(typeof(Image))]
    public class ControlMovable : MonoBehaviour, IDragHandler, IBeginDragHandler, IEndDragHandler {
        [SerializeField]
        private PanelMoveSize control;
        private Image               image;
        private Vector2             offset = Vector2.zero;
        private RectTransform       rtr;
        private Win32Internal.POINT startPos;
        [SerializeField]
        private PanelMoveSize.MovableType type;

        private void Start() {
            rtr          = (RectTransform) transform;
        }

        public void OnDrag(PointerEventData eventData) {
            var p = eventData.position;
            p.y = -(Screen.height - p.y);
            p.x /= control.scale.x;
            p.y /= control.scale.y;
            control.Move(p        + offset);
        }

        public void OnBeginDrag(PointerEventData eventData) {
            var p = eventData.position;
            p.y = -(Screen.height - p.y);
            p.x /= control.scale.x;
            p.y /= control.scale.y;
            offset = control.rTr.anchoredPosition - p;
        }

        public void OnEndDrag(PointerEventData eventData) {
        }
    }
}