// Instead of methods in the form that paint a rectangle we now want to
// make a class responsible to draw itself on the form canvas
private void formPaintClass(object sender, System.Windows.Forms.PaintEventArgs e)
{
Graphics g = this.CreateGraphics();
SquarePainter sp = new SquarePainter(g);
sp.paint();
}
// Now let's add a new type of painter class
// Let's draw also a circle
private void formPaintMultipleTypes(object sender, System.Windows.Forms.PaintEventArgs e)
{
Graphics g = this.CreateGraphics();
SquarePainter sp = new SquarePainter(g);
sp.paint();
CirclePainter cp = new CirclePainter(g);
cp.paint();
}