AWT Sample
CloseableFrame

This version of the CloseableFrame is a little more sophisticated than the version shown in class. In this version the listener class is made into an anonymous inner class of the frame.

The key piece of code is:

    addWindowListener(new WindowAdapter()
      { public void windowClosing(WindowEvent e)
          {System.exit(0);
          }
      });

This innocent looking piece of code does a lot:

• Defines a class without a name that extends the WindowAdapter class
• Adds a windowClosing method to that anonomous class (this method closes the window and exits the program)
• Inherits the the remaining six "do nothing" methods from WindowAdapter.
• Passes the object to the addWindowListener method

The syntax for the anonymous inner classes for event listeners takes some getting used to but pays off with very small and efficient generated code.

Example from CoreJava 1.1 vol 1 by Horstmann & Cornell