RadioButtonTest.java Source code

Introduction

Here is the source code for RadioButtonTest.java

Source

/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)
    
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;

/**
 * @version 1.33 2007-06-12
 * @author Cay Horstmann
 */
public class RadioButtonTest {
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                RadioButtonFrame frame = new RadioButtonFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
        });
    }
}

/**
 * A frame with a sample text label and radio buttons for selecting font sizes.
 */
class RadioButtonFrame extends JFrame {
    public RadioButtonFrame() {
        setTitle("RadioButtonTest");
        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

        // add the sample text label

        label = new JLabel("The quick brown fox jumps over the lazy dog.");
        label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE));
        add(label, BorderLayout.CENTER);

        // add the radio buttons

        buttonPanel = new JPanel();
        group = new ButtonGroup();

        addRadioButton("Small", 8);
        addRadioButton("Medium", 12);
        addRadioButton("Large", 18);
        addRadioButton("Extra large", 36);

        add(buttonPanel, BorderLayout.SOUTH);
    }

    /**
     * Adds a radio button that sets the font size of the sample text.
     * @param name the string to appear on the button
     * @param size the font size that this button sets
     */
    public void addRadioButton(String name, final int size) {
        boolean selected = size == DEFAULT_SIZE;
        JRadioButton button = new JRadioButton(name, selected);
        group.add(button);
        buttonPanel.add(button);

        // this listener sets the label font size

        ActionListener listener = new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                // size refers to the final parameter of the addRadioButton
                // method
                label.setFont(new Font("Serif", Font.PLAIN, size));
            }
        };

        button.addActionListener(listener);
    }

    public static final int DEFAULT_WIDTH = 400;
    public static final int DEFAULT_HEIGHT = 200;

    private JPanel buttonPanel;
    private ButtonGroup group;
    private JLabel label;

    private static final int DEFAULT_SIZE = 12;
}