Swing/LookAndFeel のバックアップ(No.16)

//%JAVA_HOME%/demo/jfc/SwingSet2/src/SwingSet2.java
// Possible Look & Feels
private static final String mac     = "com.sun.java.swing.plaf.mac.MacLookAndFeel";
private static final String metal   = "javax.swing.plaf.metal.MetalLookAndFeel";
private static final String motif   = "com.sun.java.swing.plaf.motif.MotifLookAndFeel";
private static final String windows = "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";
private static final String gtk     = "com.sun.java.swing.plaf.gtk.GTKLookAndFeel";
private static final String nimbus  = "com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel";

// The current Look & Feel
private static String currentLookAndFeel = metal;
private final ButtonGroup lafMenuGroup = new ButtonGroup();
public JMenuItem createLafMenuItem(JMenu menu, String label, String laf) {
  JMenuItem mi = (JRadioButtonMenuItem) menu.add(new JRadioButtonMenuItem(label));
  lafMenuGroup.add(mi);
  mi.addActionListener(new ChangeLookAndFeelAction(laf));
  mi.setEnabled(isAvailableLookAndFeel(laf));
  return mi;
}
protected static boolean isAvailableLookAndFeel(String laf) {
  try{
    Class lnfClass = Class.forName(laf);
    LookAndFeel newLAF = (LookAndFeel)(lnfClass.newInstance());
    return newLAF.isSupportedLookAndFeel();
  }catch(Exception e) {
    return false;
  }
}
//...
private class ChangeLookAndFeelAction extends AbstractAction{
  private final String laf;
  protected ChangeLookAndFeelAction(String laf) {
    super("ChangeTheme");
    this.laf = laf;
  }
  @Override public void actionPerformed(ActionEvent e) {
    setLookAndFeel(laf);
  }
}
private void setLookAndFeel(String laf) {
  if(currentLookAndFeel.equals(laf)) return;
  currentLookAndFeel = laf;
  try{
    UIManager.setLookAndFeel(currentLookAndFeel);
    SwingUtilities.updateComponentTreeUI(frame);
  }catch(Exception ex) {
    ex.printStackTrace();
    System.out.println("Failed loading L&F: " + currentLookAndFeel);
  }
}