public void DownEllipse(object sender, MouseEventArgs e)
 {
     IsDown = true;
     temp   = new Ellipse(thickness, tcolor);
     (temp as Ellipse).p1 = e.Location;
 }
 public void DownCurve(object sender, MouseEventArgs e)
 {
     IsDown = true;
     temp   = new Curve(thickness, tcolor);
     (temp as Curve).AddPoint(e.Location);
 }
 public void DownRect(object sender, MouseEventArgs e)
 {
     IsDown            = true;
     temp              = new Rect(thickness, tcolor);
     (temp as Rect).p1 = e.Location;
 }