// Fig. 11.19: RadioButtonFrame.java // Creating radio buttons using ButtonGroup and JRadioButton. import java.awt.FlowLayout; import java.awt.Font; import java.awt.event.ItemListener; import java.awt.event.ItemEvent; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.JRadioButton; import javax.swing.ButtonGroup; public class RadioButtonFrame extends JFrame { private JTextField textField; // used to display font changes private Font plainFont; // font for plain text private Font boldFont; // font for bold text private Font italicFont; // font for italic text private Font boldItalicFont; // font for bold and italic text private JRadioButton plainJRadioButton; // selects plain text private JRadioButton boldJRadioButton; // selects bold text private JRadioButton italicJRadioButton; // selects italic text private JRadioButton boldItalicJRadioButton; // bold and italic private ButtonGroup radioGroup; // buttongroup to hold radio buttons // RadioButtonFrame constructor adds JRadioButtons to JFrame public RadioButtonFrame() { super( "RadioButton Test" ); setLayout( new FlowLayout() ); // set frame layout textField = new JTextField( "Watch the font style change", 25 ); add( textField ); // add textField to JFrame // create radio buttons plainJRadioButton = new JRadioButton( "Plain", true ); boldJRadioButton = new JRadioButton( "Bold", false ); italicJRadioButton = new JRadioButton( "Italic", false ); boldItalicJRadioButton = new JRadioButton( "Bold/Italic", false ); add( plainJRadioButton ); // add plain button to JFrame add( boldJRadioButton ); // add bold button to JFrame add( italicJRadioButton ); // add italic button to JFrame add( boldItalicJRadioButton ); // add bold and italic button // create logical relationship between JRadioButtons radioGroup = new ButtonGroup(); // create ButtonGroup radioGroup.add( plainJRadioButton ); // add plain to group radioGroup.add( boldJRadioButton ); // add bold to group radioGroup.add( italicJRadioButton ); // add italic to group radioGroup.add( boldItalicJRadioButton ); // add bold and italic // create font objects plainFont = new Font( "Serif", Font.PLAIN, 14 ); boldFont = new Font( "Serif", Font.BOLD, 14 ); italicFont = new Font( "Serif", Font.ITALIC, 14 ); boldItalicFont = new Font( "Serif", Font.BOLD + Font.ITALIC, 14 ); textField.setFont( plainFont ); // set initial font to plain // register events for JRadioButtons plainJRadioButton.addItemListener( new RadioButtonHandler( plainFont ) ); boldJRadioButton.addItemListener( new RadioButtonHandler( boldFont ) ); italicJRadioButton.addItemListener( new RadioButtonHandler( italicFont ) ); boldItalicJRadioButton.addItemListener( new RadioButtonHandler( boldItalicFont ) ); } // end RadioButtonFrame constructor // private inner class to handle radio button events private class RadioButtonHandler implements ItemListener { private Font font; // font associated with this listener public RadioButtonHandler( Font f ) { font = f; // set the font of this listener } // end constructor RadioButtonHandler // handle radio button events public void itemStateChanged( ItemEvent event ) { textField.setFont( font ); // set font of textField } // end method itemStateChanged } // end private inner class RadioButtonHandler } // end class RadioButtonFrame /************************************************************************** * (C) Copyright 1992-2005 by Deitel & Associates, Inc. and * * Pearson Education, Inc. All Rights Reserved. * * * * DISCLAIMER: The authors and publisher of this book have used their * * best efforts in preparing the book. These efforts include the * * development, research, and testing of the theories and programs * * to determine their effectiveness. The authors and publisher make * * no warranty of any kind, expressed or implied, with regard to these * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or * * consequential damages in connection with, or arising out of, the * * furnishing, performance, or use of these programs. * *************************************************************************/