CodeBarn - How does "Shapes" work?

[mike vessey]

In the Shapes example code (http://www.javaranch.com/CodeBarn/shapes.jsp) how does the paint method get called?
The main method instantiates a new ShowShapes object, which seems to have a constructor method that just sets up a window and makes it visible. From where is the paint method called?
Thanks

[Marilyn de Queiroz]

The statement

setVisible( true );

causes paint() to be called.