Modification of the World class

This program adds a method named getFrame to the World class.

The new getFrame method

• returns a reference to the JFrame object
• that is used to display the world.

The program uses that reference

• to add a JButton object
• to the SOUTH location of the World.

I explained a modification very similar to this in an earlier lesson, so I won't repeat that explanation here.

A complete listing of the modified World class is provided in Listing 10.