lookandfeeldemo.java

Java语言

// Changing the look and feel.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class LookAndFeelDemo extends JFrame {
   private String strings[] = { "Metal", "Motif", "Windows" };
   private UIManager.LookAndFeelInfo looks[];
   private JRadioButton radio[];
   private ButtonGroup group;
   private JButton button;
   private JLabel label;
   private JComboBox comboBox;

   public LookAndFeelDemo()
   {
      super( "Look and Feel Demo" );

      Container c = getContentPane();

      JPanel northPanel = new JPanel();
      northPanel.setLayout( new GridLayout( 3, 1, 0, 5 ) );
      label = new JLabel( "This is a Metal look-and-feel",
                          SwingConstants.CENTER );
      northPanel.add( label );
      button = new JButton( "JButton" );
      northPanel.add( button );
      comboBox = new JComboBox( strings );
      northPanel.add( comboBox );
     
      c.add( northPanel, BorderLayout.NORTH );
      
      JPanel southPanel = new JPanel();
      radio = new JRadioButton[ strings.length ];
      group = new ButtonGroup();
      ItemHandler handler = new ItemHandler();
      southPanel.setLayout(
         new GridLayout( 1, radio.length ) );

      for ( int i = 0; i < radio.length; i++ ) {
         radio[ i ] = new JRadioButton( strings[ i ] );
         radio[ i ].addItemListener( handler );
         group.add( radio[ i ] );
         southPanel.add( radio[ i ] );
      }

      c.add( southPanel, BorderLayout.SOUTH );

      // get the installed look-and-feel information
      looks = UIManager.getInstalledLookAndFeels();

      setSize( 300, 200 );
      show();

      radio[ 0 ].setSelected( true );
   }

   private void changeTheLookAndFeel( int value )
   {
      try {
         UIManager.setLookAndFeel(
            looks[ value ].getClassName() );
         SwingUtilities.updateComponentTreeUI( this );
      }
      catch ( Exception e ) {
         e.printStackTrace();
      }
   }

   public static void main( String args[] )
   {
      LookAndFeelDemo dx = new LookAndFeelDemo();

      dx.addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               System.exit( 0 );
            }
         }
      );
   }

   private class ItemHandler implements ItemListener {
      public void itemStateChanged( ItemEvent e )
      {
         for ( int i = 0; i < radio.length; i++ )
            if ( radio[ i ].isSelected() ) {
               label.setText( "This is a " +
                  strings[ i ] + " look-and-feel" );
               comboBox.setSelectedIndex( i );
               changeTheLookAndFeel( i );
            }
      }
   }
}