Java Foundation Classes in a Nutshell

about what you can do with the component. This is so useful, in fact, that the ref-

er ence section of this book groups property accessor methods separately from

other methods.

Container s and Containment

Table 2-1 and Table 2-2 listed the GUI components available in the AWT and

Swing toolkits. In order to create a graphical user interface, however, these indi-

vidual components must be arranged within some kind of container. A container

is a component that can contain other components. All containers inherit from the

java.awt.Container base class, which itself inherits from java.awt.Component.

Main application windows and dialog boxes are commonly used containers. Each

pr ovides a window within which GUI components can be arranged to create a

user interface. A graphical application does not usually arrange all its components

dir ectly within a window or dialog box, however. Instead, an application typically

uses containers nested within other containers. For example, a dialog box that

contains two columns of text input fields above a row of push buttons might use

thr ee separate containers, one for each column of text fields and one for the row

of push buttons. Then the dialog box container contains only these three contain-

ers, instead of the full set of text fields and push buttons.

Some kinds of containers display their children in very specific ways, while others

have restrictions on the number ...