Core Swing Components - The Definitive Guide to Java Swing - page 107

Table 4-15. JButton UIResource Elements (Continued)

Property String Object Type

Button.textIconGap Integer

Button.textShiftOffset Integer

Button.toolBarBorderBackground Color

ButtonUI String

JPanel Class
The last of the basic Swing components is the JPanel component. The JPanel component
serves as both a general-purpose container object, replacing the AWT Panel container, and a
replacement for the Canvas component, for those times when you need a drawable Swing
component area.

Creating a JPanel
There are four constructors for JPanel :

public JPanel()
JPanel panel = new JPanel();

public JPanel(boolean isDoubleBuffered)
JPanel panel = new JPanel(false);

public JPanel(LayoutManager manager)
JPanel panel = new JPanel(new GridLayout(2,2));

public JPanel(LayoutManager manager, boolean isDoubleBuffered)
JPanel panel = new JPanel(new GridLayout(2,2), false);

With the constructors, you can either change the default layout manager from FlowLayout
or change the default double buffering that is performed from true to false .

Using a JPanel
You can use JPanel as your general-purpose container or as a base class for a new component.
For the general-purpose container, the procedure is simple: Just create the panel, set its layout
manager if necessary, and add components using the add() method.

JPanel panel = new JPanel();
JButton okButton = new JButton("OK");
panel.add(okButton);
JButton cancelButton = new JButton("Cancel");
panel.add(cancelButton);