import java.awt.BorderLayout;

import java.awt.Font;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JCheckBox;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

/*

 * source code from 《java核心技术 卷1 基础知识》 P326

 */

public class JCheckBoxDemo extends JFrame{

    int DEFAULT_WIDTH = 600;

    int DEFAULT_HEIGHT = 400;

    private JLabel label;

    private JCheckBox boldCheckbox;

    private JCheckBox italicCheckbox;

    private static final int FONTSIZE = 12;    

    public JCheckBoxDemo(){

        setTitle("JCheckBoxDemo");

        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

        //添加label

        label = new JLabel("The quick brown fox jumps over the lazy dog.");

        label.setFont(new Font("Serif",Font.PLAIN, FONTSIZE));

        add(label, BorderLayout.CENTER);

        //构造一个监听器，响应checkBox事件

        ActionListener actionListener = new ActionListener(){

            public void actionPerformed(ActionEvent e) {

                int mode = 0;

                if(boldCheckbox.isSelected()) mode += Font.BOLD;

                if(italicCheckbox.isSelected()) mode += Font.ITALIC;

                label.setFont(new Font("Serif", mode, FONTSIZE));

            }

        };

        //添加buttonPanel,它包含2个checkBox

        JPanel buttonPanel = new JPanel();

        add(buttonPanel, BorderLayout.SOUTH);

        //为buttonPanel添加2个checkBox

        boldCheckbox = new JCheckBox("bold");

        boldCheckbox.addActionListener(actionListener);

        buttonPanel.add(boldCheckbox);

        italicCheckbox = new JCheckBox("italic");

        italicCheckbox.addActionListener(actionListener);

        buttonPanel.add(italicCheckbox);

    }    

    public static void main(String[] args) {

        // TODO Auto-generated method stub

        //创建窗体并指定标题

        JCheckBoxDemo frame = new JCheckBoxDemo();

        //关闭窗体后退出程序

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //自动适配所有控件大小

        //frame.pack();

        //设置窗体位置在屏幕*

        frame.setLocationRelativeTo(null);

        //显示窗体

        frame.setVisible(true);

    }

}