public void DrawHighlight(bool force = false)
        {
            var lastPos = mouse.lastPoint;
            var curPos  = mouse.GetCursorPosition();

            if (mouse.Compare(lastPos, curPos) == 0 && !force)
            {
                return;
            }
            using (Graphics g = Graphics.FromHwnd(this.Handle))
            {
                g.Clear(TRANSPARENT_COLOR);
                g.FillEllipse(MouseBrush, curPos.X - EllipseRadius, curPos.Y - EllipseRadius, EllipseRadius * 2, EllipseRadius * 2);
            }
        }