Graphical user interfaces - Data Structures and Problem Solving Using Java - page 955

JWindow A top-level window that has no border. (934)
layout manager A helper object that automatically arranges components of a
container. (941)
listener adapter class Provides default implementations for a listener interface
that has more than one method. (950)
null layout A layout used to perform precise positioning. (944)
pack A method used to pack a JFrame into its smallest size given its constituent
components. (948)
paintComponent A method used to draw onto a component. Typically overrid-
den by classes that extend JPanel . (945)
repaint A method used to clear and repaint a component. (945)
setLayout A method that associates a layout with a container. (941)
show A method that makes a component visible. (948)
WindowAdapter A class that provides default implementations of the
WindowListener interface. (950)
WindowListener interface An interface used to specify the handling of window
events, such as window closing. (948)

common errors

1.

Forgetting to set a layout manager is a common mistake. If you forget it,
you'll get a default. However, it may not be the one you want.

2.

The layout manager must appear prior to the calls to add .

3.

Applying add or setting a layout manager to the wrong container is a com-
mon mistake. For instance, in a container that contains panels, applying
the add method without specifying the panel means that the add is applied
to the main container.

A missing String argument to add for BorderLayout uses "Center" as the
default. A common mistake is to specify it in the wrong case, as in
"north" . The five valid arguments are "North" , "South" , "East" , " West" , and
"Center" . In Java 1.1, if the String is the second parameter, a run-time
exception will catch the error. If you use the old style, in which the String
comes first, the error might not be detected.

4.

Special code is needed to process the window-closing event.

5.