CHANGE THE LOOK AND FEEL OF YOUR JAVA APPLICATIONS

Java applications often seem very plain next to their native
counterparts. However, it's easy to jazz them up by changing the Swing 
Look and Feel
(LAF).

The LAF system is one of Swing's most powerful features, allowing Java
applications to masquerade as native programs. By changing the look, 
you
can change how people view the application.

Java's Swing library runs by default in the Metal LAF, but all versions
of Swing ship with a ui.jar that contains a Motif LAF. In addition, the
Windows version has a Windows LAF, and the OS X version has a Mac LAF.

Follow this example to change the LAF in Java:

try {
    
UIManager.setLookAndFeel("javax.swing.plaf.motif.MotifLookAndFeel");
// 
UIManager.setLookAndFeel("javax.swing.plaf.windows.WindowsLookAndFeel");
//  
UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
//  UIManager.setLookAndFeel("com.apple.mrj.swing.MacLookAndFeel");
} catch(ClassNotFoundException cnfe) {
    cnfe.printStackTrace( );
} catch(InstantiationException ie) {
    ie.printStackTrace( );
} catch(IllegalAccessException iae) {
    iae.printStackTrace( );
} catch(UnsupportedLookAndFeelException ulafe) {
    ulafe.printStackTrace( );
}
// 'frame' is an example top level component
SwingUtilities.updateComponentTreeUI(frame);

While the UIManager gets updated inside the try/catch block, the
existing components are not updated. This is handled by the call to the
SwingUtilities method, updateComponentTreeUI(java.awt.Component). By 
passing the
top-level component of the graphical user interface (GUI) to this 
method,
all of the styles will be updated.

The Metal LAF is slightly more powerful than the others because it's
themeable. Changing the background color is only one of the wide ranges 
of
themeable properties in the Metal LAF that can be set with the 
UIManager
for a particular component or for the whole platform with a customized
Theme. For example, you can set the background of a component in any 
LAF to
be a certain color with:

    UIManager.put("Tree.background", Color.yellow);

However, the Metal LAF allows you to modify all backgrounds across the
whole look and feel with the BackgroundTheme class:

package com.generationjava.swing;

import java.awt.Color;

import javax.swing.plaf.ColorUIResource;
import javax.swing.plaf.metal.DefaultMetalTheme;

public class BackgroundTheme extends DefaultMetalTheme {

    private final ColorUIResource resource;

    public BackgroundTheme(Color color) {
        this.resource = new ColorUIResource(color);
    }

    public ColorUIResource getSecondary3( ) {
        return this.resource;
    }
}

The BackgroundTheme class can be used in the following way:

import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.UIManager;
import javax.swing.plaf.metal.MetalLookAndFeel;

....

    MetalLookAndFeel.setCurrentTheme(new BackgroundTheme( Color.yellow 
)
);
    try {
        UIManager.setLookAndFeel( new MetalLookAndFeel( ) );
    } catch(ClassNotFoundException cnfe) {
        cnfe.printStackTrace( );
    } catch(InstantiationException ie) {
        ie.printStackTrace( );
    } catch(IllegalAccessException iae) {
        iae.printStackTrace( );
    } catch(UnsupportedLookAndFeelException ulafe) {
        ulafe.printStackTrace( );
    }

NOTE: Once the MetalLookAndFeel is modified, it needs to be reloaded
with the setLookAndFeel method.

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