Designing Graphical Interfaces - Beginning Java Programming: The Object-Oriented Approach - page 473

java.lang. Object

java.awt. Component

AWT Components java.awt. Container

java.awt.Window java.awt.Panel javax.swing. JComponent

java.awt.Frame java.awt.Dialog java.awt.Applet javax.swing.JPanel Swing Components

javax.swing.JWindow javax.swing.JFrame javax.swing.JDialog javax.swing.JApplet

figure 11-6

There they are. Note how things are a bit complicated ( JPanel for instance does not extend the
AWT Panel), but the main classes you'll be working with are all part of Swing, all starting with “J”.
Annotating the class tree somewhat more, you finally get the full picture shown in Figure 11-7.

java.lang. Object

Other AWT Classes
(Font, Dimension, LayoutManager...)
Also used by Swing

java.awt. Component

AWT Components java.awt. Container

java.awt.Window java.awt.Panel javax.swing. JComponent

java.awt.Frame java.awt.Dialog java.awt.Applet javax.swing.JPanel Swing Components

javax.swing.JWindow javax.swing.JFrame javax.swing.JDialog javax.swing.JApplet

Heavyweight Swing Classes

Swing Containers

AWT Containers

figure 11-7

comparing layout managers

Now that you have a clear picture of the GUI class hierarchy, you are ready to move on to the next
topic. Some of the general AWT classes that are reused in Swing represent layout managers. What is
a layout manager? Basically, an object specifying the way components in a container should be laid
out. Java offers a number of them out of the box, and you can combine these (by nesting containers
inside each other) to create relatively intricate layouts.