int id = GUIUtility.GetControlID(FocusType.Passive);

        Vector3 delta = Vector3.zero;

        Event e = Event.current;
        switch (e.GetTypeForControl(id))
        {
            case EventType.Layout:
            {
                HandleUtility.AddControl(id, Vector2.Distance(e.mousePosition, HandleUtility.WorldToGUIPoint(point)));
                break;
            }
            case EventType.Repaint:
            {
                /* visual Handle code here */
                break;
            }
            case EventType.MouseDown:
            {
                if (HandleUtility.nearestControl == id)
                {
                    GUIUtility.hotControl = id;
                    e.Use();
                }
                break;
            }
            case EventType.MouseUp:
            {
                if (GUIUtility.hotControl == id)
                {
                    if (HandlesM.delta == Vector3.zero)
                        onClick?.Invoke();

                    GUIUtility.hotControl = 0;
                    e.Use();

                    HandlesM.delta = Vector3.zero;
                }
                break;
            }
            case EventType.MouseDrag:
            {
                if (GUIUtility.hotControl == id)
                {
                    /* drag specific code here */

                    HandlesM.delta = e.delta;
                    GUI.changed = true;
                    e.Use();
                }
                break;
            }
        }

        return delta;