Example not clear +java magazine JANUARY/FEBRUARY 2012

Question

In java magazine JANUARY/FEBRUARY 2012 , they are interested subjects which discuss " Using JLayer in Your
Swing Applications",
there are one java example about Drawing components into a temporary
image ,but it is not clear because some Variables not define like img,px
kindly can any one know that write complete example .
@Override
public void paint(Graphics g, JComponent c) {
//draw regular
super.paint(g,c);
//draw into buffer
Graphics2D g2 = img.createGraphics();
int ih = *img*.getHeight();
int iw = img.getWidth();
//fill with white
g2.setPaint(Color.WHITE);
g2.fillRect(0, 0, img.getWidth(), img.getHeight());
//render view component scaled and translated
Graphics2D g3 = (Graphics2D) g2.create();
g3.translate(-*pt*.x + iw, *-pt*.y + ih*2);
g3.scale(2, 2);
g3.translate(-pt.x/2 - iw/4, -pt.y/2 - ih/4);
super.paint(g3,c);
g3.dispose();
//draw black border
g2.setPaint(Color.BLACK);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.
VALUE_ANTIALIAS_ON);
g2.setStroke(new BasicStroke(3));
g2.draw(new Ellipse2D.Double(0,0,iw,ih));
g2.drawRect(0,0, iw-1, ih-1);
g2.dispose();
//draw image to screen
Shape oldClip = g.getClip();
int mx = pt.x-img.getWidth()/2;
int my = pt.y-img.getHeight();
g.setClip(new Ellipse2D.Double(mx,my,iw,ih));
g.drawImage(img, mx, my, null);
g.setClip(oldClip);
}Thanks
Sameer
Edited by: sabre150 on Feb 17, 2012 9:45 PM
Added code tags

Answer 1

The online article has an embedded link you can use to download the complete source code.
http://www.oraclejavamagazine-digital.com/javamagazine/20120102?folio=37#pg38
The second column from the right on the page above says:
>
NOTE: The source code for the examples described in this article can be downloaded here.
>
The word 'here' is a link you can click to download the complete source code.