LookAndFeelPrefs.java Source code

Introduction

Here is the source code for LookAndFeelPrefs.java

Source

/*
 * Copyright (c) 2004 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 3nd Edition.
 * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
 * You may study, use, and modify it for any non-commercial purpose,
 * including teaching and use in open-source projects.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book, 
 * please visit http://www.davidflanagan.com/javaexamples3.
 */

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.prefs.Preferences;

import javax.swing.ButtonGroup;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class LookAndFeelPrefs {
    public static final String PREF_NAME = "preferredLookAndFeelClassName";

    /**
     * Get the desired look and feel from a per-user preference. If the
     * preferences doesn't exist or is unavailable, use the default look and feel.
     * The preference is shared by all classes in the same package as prefsClass.
     */
    public static void setPreferredLookAndFeel(Class prefsClass) {
        Preferences prefs = Preferences.userNodeForPackage(prefsClass);
        String defaultLAF = UIManager.getSystemLookAndFeelClassName();
        String laf = prefs.get(PREF_NAME, defaultLAF);
        try {
            UIManager.setLookAndFeel(laf);
        } catch (Exception e) { // ClassNotFound or InstantiationException
            // An exception here is probably caused by a bogus preference.
            // Ignore it silently; the user will make do with the default LAF.
        }
    }

    /**
     * Create a menu of radio buttons listing the available Look and Feels. When
     * the user selects one, change the component hierarchy under frame to the new
     * LAF, and store the new selection as the current preference for the package
     * containing class c.
     */
    public static JMenu createLookAndFeelMenu(final Class prefsClass, final ActionListener listener) {
        // Create the menu
        final JMenu plafmenu = new JMenu("Look and Feel");

        // Create an object used for radio button mutual exclusion
        ButtonGroup radiogroup = new ButtonGroup();

        // Look up the available look and feels
        UIManager.LookAndFeelInfo[] plafs = UIManager.getInstalledLookAndFeels();

        // Find out which one is currently used
        String currentLAFName = UIManager.getLookAndFeel().getClass().getName();

        // Loop through the plafs, and add a menu item for each one
        for (int i = 0; i < plafs.length; i++) {
            String plafName = plafs[i].getName();
            final String plafClassName = plafs[i].getClassName();

            // Create the menu item
            final JMenuItem item = plafmenu.add(new JRadioButtonMenuItem(plafName));
            item.setSelected(plafClassName.equals(currentLAFName));

            // Tell the menu item what to do when it is selected
            item.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent event) {
                    // Set the new look and feel
                    try {
                        UIManager.setLookAndFeel(plafClassName);
                    } catch (UnsupportedLookAndFeelException e) {
                        // Sometimes a Look-and-Feel is installed but not
                        // supported, as in the Windows LaF on Linux platforms.
                        JOptionPane.showMessageDialog(plafmenu,
                                "The selected Look-and-Feel is " + "not supported on this platform.",
                                "Unsupported Look And Feel", JOptionPane.ERROR_MESSAGE);
                        item.setEnabled(false);
                    } catch (Exception e) { // ClassNotFound or Instantiation
                        item.setEnabled(false); // shouldn't happen
                    }

                    // Make the selection persistent by storing it in prefs.
                    Preferences p = Preferences.userNodeForPackage(prefsClass);
                    p.put(PREF_NAME, plafClassName);

                    // Invoke the supplied action listener so the calling
                    // application can update its components to the new LAF
                    // Reuse the event that was passed here.
                    listener.actionPerformed(event);
                }
            });

            // Only allow one menu item to be selected at once
            radiogroup.add(item);
        }

        return plafmenu;
    }
}