• 201771010113 李婷华 《面向对象程序设计(java)》


    一.理论知识部分

    设计模式(Design pattern)是设计者一种流行的思考设计问题的方法,是一套被反复使用,多数人知晓的,经过分类编目的,代码设计经验的总结。使用设计模式是为了可重用代码、让代码更容易被他人理解、保证代码可靠性。每一个模式描述了一个不断重复发生的设计问题,以及该问题的核心解决方案

    模型-视图-控制器设计模式(Model –ViewController )是Java EE平台下创建 Web 应用程序 的重要设计模式。

    MVC设计模式 – Model(模型):是程序中用于处理程序数据逻辑的部分,通常模型负责在数据库中存取数据。– View(视图):是程序中处理数据显示的部分,通常视图依据模型存取的数据创建。 – Controller(控制器):是程序中处理用户交互的部分。通常控制器负责从视图读取数据,控制用户输入,并向模型发送数据。

    MVC模式可应用于Java的GUI组件设计中。MVC模式GUI组件设计的唯一的模式,还有很多设计的模式(设计方法)。

    Java组件有内容、外观、行为三个主要元素;这三个主要元素与模型—视图—控制器模式的 三部件的对应关系为:内容——控制器(作用:处理用户输入)  外观——视图(作用:显示内容)行为——模型(作用:存储内容)

    布局管理器是一组类。实现 java.awt.LayoutManager 接口;决定容器中组件的位置和大小

    Java.awt包中定义了5种布局管理类,每一种布局管理类对应一种布局策略。每个容器都有与之相关的默认布局管理器。当一个容器选定一种布局策略时,它应该创建该 策略对应的布局管理器对象,并将此对象设置为 自己的布局管理器。

    5种布局管理器:(1)FlowLayout:流布局(Applet和Panel的默认布局管理器) (2)BorderLayout:边框布局( Window、Frame和Dialog的默认布局管理器)(3)GridLayout:网格布局(4)GridBagLayout: 网格组布局(5)CardLayout :卡片布局

    FlowLayout Manager 组件采用从左到右,从上到下逐行摆放。

    GridBagLayout不需要组件的尺寸一致,容许组件扩展到多行、多列。

    文本输入

    (1)文本域(JTextField) : 用于获取单行文本输入。

    (2)文本区(JTextArea)组件可让用户输入多行文 本。生成JTextArea组件对象时,可以指定文本 区的行数和列数: textArea = new JTextArea(8, 40);

    (3)文本区与文本域的异同相同之处: 文本域和文本区组件都可用于获取文本输入。

    不同之处:  文本域只能接受单行文本的输入;  文本区能够接受多行文本的输入。

    (4)文本区JTextArea的常用API:Java.swing. JTextArea 1.2 – JTextArea(int rows, int cols)

    构造一个rows行cols列的文本区对象 – JTextArea(String text,int rows, int cols)

    用初始文本构造一个文本区对象 – void setRows(int rows)

    设置文本域使用的行数 – void append(String newText)

    将给定文本附加到文本区中已有文本的后面 – void setLineWrap(boolean wrap)

    打开或关闭换行

    (5)标签组件:标签是容纳文本的组件。它们没有任何修饰(如没有边界 ),也不响应用户输入。

     标签的常用用途之一就是标识组件,例如标识文本域。

    二.实验部分

    1、实验目的与要求

    (1) 掌握GUI布局管理器用法;

    (2) 掌握各类Java Swing组件用途及常用API;

    2、实验内容和步骤

    实验1: 导入第12章示例程序,测试程序并进行组内讨论。

    测试程序1

    l 在elipse IDE中运行教材479页程序12-1,结合运行结果理解程序;

    l 掌握各种布局管理器的用法;

    l 理解GUI界面中事件处理技术的用途。

    l 在布局管理应用代码处添加注释;

    package calculator;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.34 2015-06-12
     * @author Cay Horstmann
     */
    public class Calculator
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             CalculatorFrame frame = new CalculatorFrame();
             frame.setTitle("Calculator");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    Calculator
    package calculator;
    
    import javax.swing.*;
    
    /**
     * A frame with a calculator panel.
     */
    public class CalculatorFrame extends JFrame
    {
       public CalculatorFrame()
       {
          add(new CalculatorPanel());
          pack();
       }
    }
    CalculatorFrame
    package calculator;
    
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    
    /**
     * A panel with calculator buttons and a result display.
     */
    public class CalculatorPanel extends JPanel
    {
       private JButton display;
       private JPanel panel;
       private double result;
       private String lastCommand;
       private boolean start;
    
       public CalculatorPanel()//生产GUI的组件写在构造器中
       {
          setLayout(new BorderLayout());
    
          result = 0;
          lastCommand = "=";
          start = true;
    
          // add the display
    
          display = new JButton("0");//初始化的Label值,完成计算结果的显示内容
          display.setEnabled(false);//定义为flase,计算结果不能更改,仅具有显示功能
          add(display, BorderLayout.NORTH);//显示在最上方
    
          ActionListener insert = new InsertAction();
          ActionListener command = new CommandAction();
    
          // add the buttons in a 4 x 4 grid
    
          panel = new JPanel();//panel是一个容器组件
          panel.setLayout(new GridLayout(4, 4));//设置一个4*4的网格布局管理器
    
          addButton("0", insert);//
          addButton("1", insert);
          addButton("2", insert);
          addButton("/", command);
    
          addButton("3", insert);
          addButton("4", insert);
          addButton("5", insert);
          addButton("*", command);
    
          addButton("6", insert);
          addButton("7", insert);
          addButton("8", insert);
          addButton("-", command);
    
          addButton("9", insert);
          addButton(".", insert);
          addButton("=", command);
          addButton("+", command);
          
          add(panel, BorderLayout.CENTER);
          
          /*JButton b1=new JButton("验证");
          add(b1,BorderLayout.SOUTH);
          
          JButton bl=new JButton("验证 1");
          add(bl,BorderLayout.WEST);
          JButton br=new JButton("验证2");
          add(br,BorderLayout.EAST);*/
    
       }
    
       /**
        * Adds a button to the center panel.
        * @param label the button label
        * @param listener the button listener
        */
       private void addButton(String label, ActionListener listener)
       {
          JButton button = new JButton(label);
          button.addActionListener(listener);//将一个监听器添加到按钮中
          panel.add(button);//将button添加到panel组件上
       }
    
       /**
        * This action inserts the button action string to the end of the display text.
        */
       private class InsertAction implements ActionListener//实现了一个监听器接口
       {
          public void actionPerformed(ActionEvent event)
          {
             String input = event.getActionCommand();
             if (start)
             {
                display.setText("");
                start = false;
             }
             display.setText(display.getText() + input);
          }
       }
    
       /**
        * This action executes the command that the button action string denotes.
        */
       private class CommandAction implements ActionListener
       {
          public void actionPerformed(ActionEvent event)
          {
             String command = event.getActionCommand();//发出动作上的label
    
             if (start)
             {
                if (command.equals("-"))
                {
                   display.setText(command);//setTest在display上显示“-”
                   start = false;
                }
                else lastCommand = command;
             }
             else
             {
                calculate(Double.parseDouble(display.getText()));//通过parseDouble转换成数字
                lastCommand = command;
                start = true;
             }
          }
       }
    
       /**
        * Carries out the pending calculation.
        * @param x the value to be accumulated with the prior result.
        */
       public void calculate(double x)
       {
          if (lastCommand.equals("+")) result += x;
          else if (lastCommand.equals("-")) result -= x;
          else if (lastCommand.equals("*")) result *= x;
          else if (lastCommand.equals("/")) result /= x;
          else if (lastCommand.equals("=")) result = x;
          display.setText("" + result);//进行字符串的转换
       }
    }
    CalculatorPanel

    测试程序2

    l 在elipse IDE中调试运行教材486页程序12-2,结合运行结果理解程序;

    l 掌握各种文本组件的用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package text;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.41 2015-06-12
     * @author Cay Horstmann
     */
    public class TextComponentTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             JFrame frame = new TextComponentFrame();//生成 TextComponentFrame类的GUI界面对象
             frame.setTitle("TextComponentTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//关闭界面的按钮操作
             frame.setVisible(true);//使结果可见
          });
       }
    }
    TextComponentTest
    package text;
    
    import java.awt.BorderLayout;
    import java.awt.GridLayout;
    
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JPanel;
    import javax.swing.JPasswordField;
    import javax.swing.JScrollPane;
    import javax.swing.JTextArea;
    import javax.swing.JTextField;
    import javax.swing.SwingConstants;
    
    /**
     * A frame with sample text components.
     */
    public class TextComponentFrame extends JFrame
    {  //定义网格的行数、列数
       public static final int TEXTAREA_ROWS = 8;
       public static final int TEXTAREA_COLUMNS = 20;
    
       public TextComponentFrame()
       {
          JTextField textField = new JTextField();//创建一个新的文本域
          JPasswordField passwordField = new JPasswordField();
    
          JPanel northPanel = new JPanel();//构造一个JPanel组件
          northPanel.setLayout(new GridLayout(2, 2));//设置布局管理器
          northPanel.add(new JLabel("User name: ", SwingConstants.RIGHT));//指定右对齐标签
          northPanel.add(textField);
          northPanel.add(new JLabel("Password: ", SwingConstants.RIGHT));
          northPanel.add(passwordField);
    
          add(northPanel, BorderLayout.NORTH);//add方法
    
          JTextArea textArea = new JTextArea(TEXTAREA_ROWS, TEXTAREA_COLUMNS);
          JScrollPane scrollPane = new JScrollPane(textArea);
    
          add(scrollPane, BorderLayout.CENTER);
    
          // add button to append text into the text area
    
          JPanel southPanel = new JPanel();
    
          JButton insertButton = new JButton("Insert");
          southPanel.add(insertButton);
          insertButton.addActionListener(event ->
             textArea.append("User name: " + textField.getText() + " Password: "
                + new String(passwordField.getPassword()) + "
    "));
    
          add(southPanel, BorderLayout.SOUTH);
          pack();
       }
    }
    TextComponentFrame

    测试程序3

    l 在elipse IDE中调试运行教材489页程序12-3,结合运行结果理解程序;

    l 掌握复选框组件的用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package checkBox;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.34 2015-06-12
     * @author Cay Horstmann
     */
    public class CheckBoxTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             JFrame frame = new CheckBoxFrame();
             frame.setTitle("CheckBoxTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    CheckBoxTest
    package checkBox;
    
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    
    /**
     * A frame with a sample text label and check boxes for selecting font attributes.
     */
    public class CheckBoxFrame extends JFrame
    {
       private JLabel label;
       private JCheckBox bold;
       private JCheckBox italic;
       private static final int FONTSIZE = 24;
    
       public CheckBoxFrame()
       {
          // 添加示例文本标签
    
          label = new JLabel("The quick brown fox jumps over the lazy dog.");
          label.setFont(new Font("Serif", Font.BOLD, FONTSIZE));
          add(label, BorderLayout.CENTER);
    
          // 字体属性
          // 复选框状态的标签
    
          ActionListener listener = event -> {
             int mode = 0;
             if (bold.isSelected()) mode += Font.BOLD;
             if (italic.isSelected()) mode += Font.ITALIC;
             label.setFont(new Font("Serif", mode, FONTSIZE));
          };
    
          // 添加复选框
    
          JPanel buttonPanel = new JPanel();
    
          bold = new JCheckBox("Bold");
          bold.addActionListener(listener);
          bold.setSelected(true);
          buttonPanel.add(bold);
    
          italic = new JCheckBox("Italic");
          italic.addActionListener(listener);
          buttonPanel.add(italic);
    
          add(buttonPanel, BorderLayout.SOUTH);
          pack();
       }
    }
    CheckBoxFrame

    测试程序4

    l 在elipse IDE中调试运行教材491页程序12-4,运行结果理解程序;

    l 掌握单选按钮组件的用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package radioButton;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.34 2015-06-12
     * @author Cay Horstmann
     */
    public class RadioButtonTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             JFrame frame = new RadioButtonFrame();
             frame.setTitle("RadioButtonTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    RadioButtonTest
    package radioButton;
    
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    
    /**
     * A frame with a sample text label and radio buttons for selecting font sizes.
     */
    public class RadioButtonFrame extends JFrame//单选按钮
    { //定义四个私有属性
       private JPanel buttonPanel;
       private ButtonGroup group;
       private JLabel label;
       private static final int DEFAULT_SIZE = 36;
    
       public RadioButtonFrame()
       {      
          // 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));//设置新字体
          add(label, BorderLayout.CENTER);
    
          // add the radio buttons
    
          buttonPanel = new JPanel();
          group = new ButtonGroup();
         //添加单选框按钮
          addRadioButton("Small", 8);
          addRadioButton("Medium", 12);
          addRadioButton("Large", 18);
          addRadioButton("Extra large", 36);
    
          add(buttonPanel, BorderLayout.SOUTH);
          pack();//调整窗口的大小
       }
    
       /**
        * 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, int size)
       {
          boolean selected = size == DEFAULT_SIZE;//布尔类型,大小的定义
          JRadioButton button = new JRadioButton(name, selected);
          group.add(button);
          buttonPanel.add(button);
    
          // this listener sets the label font size
          //这个监听器设置标签字体大小
    
          ActionListener listener = event -> label.setFont(new Font("Serif", Font.PLAIN, size));//表明新的字体,大小
    
          button.addActionListener(listener);
       }
    }
    RadioButtonFrame

    测试程序5

    l 在elipse IDE中调试运行教材494页程序12-5,结合运行结果理解程序;

    l 掌握边框的用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package border;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.34 2015-06-13
     * @author Cay Horstmann
     */
    public class BorderTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             JFrame frame = new BorderFrame();
             frame.setTitle("BorderTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    BorderTest
    package border;
    
    import java.awt.*;
    import javax.swing.*;
    import javax.swing.border.*;
    
    /**
     * A frame with radio buttons to pick a border style.
     */
    public class BorderFrame extends JFrame
    {
       private JPanel demoPanel;
       private JPanel buttonPanel;
       private ButtonGroup group;
    
       public BorderFrame()
       {
          demoPanel = new JPanel();
          buttonPanel = new JPanel();
          group = new ButtonGroup();
          
          //设置不同的边框类型按钮,共六种(提供标准 Border 对象的工厂类)
          addRadioButton("Lowered bevel", BorderFactory.createLoweredBevelBorder());
          addRadioButton("Raised bevel", BorderFactory.createRaisedBevelBorder());
          addRadioButton("Etched", BorderFactory.createEtchedBorder());
          addRadioButton("Line", BorderFactory.createLineBorder(Color.BLUE));
          addRadioButton("Matte", BorderFactory.createMatteBorder(10, 10, 10, 10, Color.BLUE));
          addRadioButton("Empty", BorderFactory.createEmptyBorder());
          
          Border etched = BorderFactory.createEtchedBorder();
          Border titled = BorderFactory.createTitledBorder(etched, "Border types");
          buttonPanel.setBorder(titled);
    
          setLayout(new GridLayout(2, 1));
          add(buttonPanel);
          add(demoPanel);
          pack();
       }
    
       public void addRadioButton(String buttonName, Border b)
       {
          JRadioButton button = new JRadioButton(buttonName);
          button.addActionListener(event -> demoPanel.setBorder(b));
          group.add(button);
          buttonPanel.add(button);
       }
    }
    BorderFrame

    测试程序6

    l 在elipse IDE中调试运行教材498页程序12-6,结合运行结果理解程序;

    l 掌握组合框组件的用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package comboBox;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.35 2015-06-12
     * @author Cay Horstmann
     */
    public class ComboBoxTest
    {
       public static void main(String[] args)
       {
      
          EventQueue.invokeLater(() -> {
         
             JFrame frame = new ComboBoxFrame();
          
             frame.setTitle("ComboBoxTest");
            
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          
             frame.setVisible(true);
          });
       }
    }
    ComboBoxTest
    package comboBox;
    
    import java.awt.BorderLayout;
    import java.awt.Font;
    
    import javax.swing.JComboBox;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JPanel;
    
    /**
     * A frame with a sample text label and a combo box for selecting font faces.
     */
    public class ComboBoxFrame extends JFrame
    {
       private JComboBox<String> faceCombo;//定义组合框面
       private JLabel label;//定义标签
       private static final int DEFAULT_SIZE = 24;
    
       public ComboBoxFrame()
       {
          // 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));//设置组件的字体
          add(label, BorderLayout.CENTER);
    
          // make a combo box and add face names
          //调用addItem方法添加选项
          faceCombo = new JComboBox<>();
          faceCombo.addItem("Serif");
          faceCombo.addItem("SansSerif");
          faceCombo.addItem("Monospaced");
          faceCombo.addItem("Dialog");
          faceCombo.addItem("DialogInput");
    
          // the combo box listener changes the label font to the selected face name
    
          faceCombo.addActionListener(event ->//组合框产生一个动作事件
             label.setFont(
                new Font(faceCombo.getItemAt(faceCombo.getSelectedIndex()), 
                   Font.PLAIN, DEFAULT_SIZE)));
    
          // add combo box to a panel at the frame's southern border
    
          JPanel comboPanel = new JPanel();
          comboPanel.add(faceCombo);
          add(comboPanel, BorderLayout.SOUTH);
          pack();
       }
    }
    ComboBoxFrame

    测试程序7

    l 在elipse IDE中调试运行教材501页程序12-7,结合运行结果理解程序;

    l 掌握滑动条组件的用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package slider;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.15 2015-06-12
     * @author Cay Horstmann
     */
    public class SliderTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             SliderFrame frame = new SliderFrame();
             frame.setTitle("SliderTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    SliderTest
    package slider;
    
    import java.awt.*;
    import java.util.*;
    import javax.swing.*;
    import javax.swing.event.*;
    
    /**
     * A frame with many sliders and a text field to show slider values.
     */
    public class SliderFrame extends JFrame {
        private JPanel sliderPanel;
        private JTextField textField;
        private ChangeListener listener;
    
        public SliderFrame() {
            sliderPanel = new JPanel();
            sliderPanel.setLayout(new GridBagLayout());
    
            // common listener for all sliders
            listener = event -> {
                // update text field when the slider value changes
                JSlider source = (JSlider) event.getSource();
                textField.setText("" + source.getValue());
            };
    
            // add a plain slider
    
            JSlider slider = new JSlider();
            addSlider(slider, "Plain");
    
            // add a slider with major and minor ticks
    
            slider = new JSlider();
            slider.setPaintTicks(true);
            slider.setMajorTickSpacing(20);
            slider.setMinorTickSpacing(5);
            addSlider(slider, "Ticks");
    
            // add a slider that snaps to ticks
    
            slider = new JSlider();
            slider.setPaintTicks(true);
            slider.setSnapToTicks(true);
            slider.setMajorTickSpacing(20);
            slider.setMinorTickSpacing(5);
            addSlider(slider, "Snap to ticks");
    
            // add a slider with no track
    
            slider = new JSlider();
            slider.setPaintTicks(true);
            slider.setMajorTickSpacing(20);
            slider.setMinorTickSpacing(5);
            slider.setPaintTrack(false);
            addSlider(slider, "No track");
    
            // add an inverted slider
    
            slider = new JSlider();
            slider.setPaintTicks(true);
            slider.setMajorTickSpacing(20);
            slider.setMinorTickSpacing(5);
            slider.setInverted(true);
            addSlider(slider, "Inverted");
    
            // add a slider with numeric labels
    
            slider = new JSlider();
            slider.setPaintTicks(true);
            slider.setPaintLabels(true);
            slider.setMajorTickSpacing(20);
            slider.setMinorTickSpacing(5);
            addSlider(slider, "Labels");
    
            // add a slider with alphabetic labels
    
            slider = new JSlider();
            slider.setPaintLabels(true);
            slider.setPaintTicks(true);
            slider.setMajorTickSpacing(20);
            slider.setMinorTickSpacing(5);
    
            Dictionary<Integer, Component> labelTable = new Hashtable<>();
            labelTable.put(0, new JLabel("A"));
            labelTable.put(20, new JLabel("B"));
            labelTable.put(40, new JLabel("C"));
            labelTable.put(60, new JLabel("D"));
            labelTable.put(80, new JLabel("E"));
            labelTable.put(100, new JLabel("F"));
    
            slider.setLabelTable(labelTable);
            addSlider(slider, "Custom labels");
    
            // add a slider with icon labels
    
            slider = new JSlider();
            slider.setPaintTicks(true);// 显示标记
            slider.setPaintLabels(true);// 确定是否在滑块上绘制标签
            slider.setSnapToTicks(true);// 最靠近用户放置滑块处的刻度标记的值
            slider.setMajorTickSpacing(20);// 大标尺标记
            slider.setMinorTickSpacing(20);// 小标尺标记
    
            labelTable = new Hashtable<Integer, Component>();
    
            // add card images
    
            labelTable.put(0, new JLabel(new ImageIcon("nine.gif")));
            labelTable.put(20, new JLabel(new ImageIcon("ten.gif")));
            labelTable.put(40, new JLabel(new ImageIcon("jack.gif")));
            labelTable.put(60, new JLabel(new ImageIcon("queen.gif")));
            labelTable.put(80, new JLabel(new ImageIcon("king.gif")));
            labelTable.put(100, new JLabel(new ImageIcon("ace.gif")));
    
            slider.setLabelTable(labelTable);
            addSlider(slider, "Icon labels");
    
            // add the text field that displays the slider value
    
            textField = new JTextField();
            add(sliderPanel, BorderLayout.CENTER);
            add(textField, BorderLayout.SOUTH);
            pack();
        }
    
        /**
         * Adds a slider to the slider panel and hooks up the listener
         * 
         * @param s           the slider
         * @param description the slider description
         */
        public void addSlider(JSlider s, String description) {
            s.addChangeListener(listener);
            JPanel panel = new JPanel();
            panel.add(s);
            panel.add(new JLabel(description));
            panel.setAlignmentX(Component.LEFT_ALIGNMENT);
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridy = sliderPanel.getComponentCount();
            gbc.anchor = GridBagConstraints.WEST;
            sliderPanel.add(panel, gbc);
        }
    }
    SliderFrame

    测试程序8

    l 在elipse IDE中调试运行教材512页程序12-8,结合运行结果理解程序;

    l 掌握菜单的创建、菜单事件监听器、复选框和单选按钮菜单项、弹出菜单以及快捷键和加速器的用法。

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package menu;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.24 2012-06-12
     * @author Cay Horstmann
     */
    public class MenuTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             JFrame frame = new MenuFrame();
             frame.setTitle("MenuTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    MenuTest
    package menu;
    
    import java.awt.event.*;
    import javax.swing.*;
    
    /**
     * A frame with a sample menu bar.
     */
    public class MenuFrame extends JFrame
    {
       private static final int DEFAULT_WIDTH = 300;
       private static final int DEFAULT_HEIGHT = 200;
       private Action saveAction;
       private Action saveAsAction;
       private JCheckBoxMenuItem readonlyItem;
       private JPopupMenu popup;
    
       /**
        * A sample action that prints the action name to System.out
        */
       class TestAction extends AbstractAction
       {
          public TestAction(String name)
          {
             super(name);
          }
    
          public void actionPerformed(ActionEvent event)
          {
             System.out.println(getValue(Action.NAME) + " selected.");
          }
       }
    
       public MenuFrame()
       {
          setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
    
          JMenu fileMenu = new JMenu("File");
          fileMenu.add(new TestAction("New"));
    
          //演示加速器
    
          JMenuItem openItem = fileMenu.add(new TestAction("Open"));
          openItem.setAccelerator(KeyStroke.getKeyStroke("ctrl O"));
    
          fileMenu.addSeparator();
    
          saveAction = new TestAction("Save");
          JMenuItem saveItem = fileMenu.add(saveAction);
          saveItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S"));
    
          saveAsAction = new TestAction("Save As");
          fileMenu.add(saveAsAction);
          fileMenu.addSeparator();
    
          fileMenu.add(new AbstractAction("Exit")
             {
                public void actionPerformed(ActionEvent event)
                {
                   System.exit(0);
                }
             });
    
          //演示复选框和单选按钮菜单
    
          readonlyItem = new JCheckBoxMenuItem("Read-only");
          readonlyItem.addActionListener(new ActionListener()
             {
                public void actionPerformed(ActionEvent event)
                {
                   boolean saveOk = !readonlyItem.isSelected();
                   saveAction.setEnabled(saveOk);
                   saveAsAction.setEnabled(saveOk);
                }
             });
    
          ButtonGroup group = new ButtonGroup();
    
          JRadioButtonMenuItem insertItem = new JRadioButtonMenuItem("Insert");
          insertItem.setSelected(true);
          JRadioButtonMenuItem overtypeItem = new JRadioButtonMenuItem("Overtype");
    
          group.add(insertItem);
          group.add(overtypeItem);
    
          //演示图标
    
          Action cutAction = new TestAction("Cut");
          cutAction.putValue(Action.SMALL_ICON, new ImageIcon("cut.gif"));
          Action copyAction = new TestAction("Copy");
          copyAction.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif"));
          Action pasteAction = new TestAction("Paste");
          pasteAction.putValue(Action.SMALL_ICON, new ImageIcon("paste.gif"));
    
          JMenu editMenu = new JMenu("Edit");
          editMenu.add(cutAction);
          editMenu.add(copyAction);
          editMenu.add(pasteAction);
    
          // 演示嵌套菜单
    
          JMenu optionMenu = new JMenu("Options");
    
          optionMenu.add(readonlyItem);
          optionMenu.addSeparator();
          optionMenu.add(insertItem);
          optionMenu.add(overtypeItem);
    
          editMenu.addSeparator();
          editMenu.add(optionMenu);
    
          // 说明助记符
    
          JMenu helpMenu = new JMenu("Help");
          helpMenu.setMnemonic('H');
    
          JMenuItem indexItem = new JMenuItem("Index");
          indexItem.setMnemonic('I');
          helpMenu.add(indexItem);
    
          //您还可以向操作添加助记符键
          Action aboutAction = new TestAction("About");
          aboutAction.putValue(Action.MNEMONIC_KEY, new Integer('A'));
          helpMenu.add(aboutAction);
          
          // 将所有顶级菜单添加到菜单栏
    
          JMenuBar menuBar = new JMenuBar();
          setJMenuBar(menuBar);
    
          menuBar.add(fileMenu);
          menuBar.add(editMenu);
          menuBar.add(helpMenu);
    
          // 显示弹出窗口
    
          popup = new JPopupMenu();
          popup.add(cutAction);
          popup.add(copyAction);
          popup.add(pasteAction);
    
          JPanel panel = new JPanel();
          panel.setComponentPopupMenu(popup);
          add(panel);
       }
    MenuFrame

    测试程序9

    l 在elipse IDE中调试运行教材517页程序12-9,结合运行结果理解程序;

    l 掌握工具栏和工具提示的用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package toolBar;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.14 2015-06-12
     * @author Cay Horstmann
     */
    public class ToolBarTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             ToolBarFrame frame = new ToolBarFrame();
             frame.setTitle("ToolBarTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    ToolBarTest
    package toolBar;
    
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    
    /**
     * A frame with a toolbar and menu for color changes.
     */
    public class ToolBarFrame extends JFrame
    {  //定义两个私有属性
       private static final int DEFAULT_WIDTH = 300;
       private static final int DEFAULT_HEIGHT = 200;
       private JPanel panel;
    
       public ToolBarFrame() //定义工具提示类
       {
          setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
    
          // add a panel for color change
    
          panel = new JPanel();//创建新的JPanel
          add(panel, BorderLayout.CENTER);
    
          // set up actions
          //建立动作
    
          Action blueAction = new ColorAction("Blue", new ImageIcon("blue-ball.gif"), Color.BLUE);
          Action yellowAction = new ColorAction("Yellow", new ImageIcon("yellow-ball.gif"),
                Color.YELLOW);
          Action redAction = new ColorAction("Red", new ImageIcon("red-ball.gif"), Color.RED);
    
          Action exitAction = new AbstractAction("Exit", new ImageIcon("exit.gif"))
             {
                public void actionPerformed(ActionEvent event)
                {
                   System.exit(0);
                }
             };
          exitAction.putValue(Action.SHORT_DESCRIPTION, "Exit");
    
          // populate toolbar
    
          JToolBar bar = new JToolBar();
          bar.add(blueAction);//用Action对象填充工具栏
          bar.add(yellowAction);
          bar.add(redAction);
          bar.addSeparator();//用分隔符将按钮分组
          bar.add(exitAction);
          add(bar, BorderLayout.NORTH);
    
          // populate menu
    
          JMenu menu = new JMenu("Color");//显示颜色的菜单
          menu.add(yellowAction);//在菜单添加颜色动作
          menu.add(blueAction);
          menu.add(redAction);
          menu.add(exitAction);
          JMenuBar menuBar = new JMenuBar();
          menuBar.add(menu);
          setJMenuBar(menuBar);
       }
    
       /**
        * The color action sets the background of the frame to a given color.
        */
       class ColorAction extends AbstractAction
       {
          public ColorAction(String name, Icon icon, Color c)
          {
             putValue(Action.NAME, name);//动作名称,显示在按钮和菜单
             putValue(Action.SMALL_ICON, icon);//存储小图标的地方;显示在按钮、菜单项或工具栏中
             putValue(Action.SHORT_DESCRIPTION, name + " background");
             putValue("Color", c);
          }
    
          public void actionPerformed(ActionEvent event)
          {
             Color c = (Color) getValue("Color");
             panel.setBackground(c);
          }
       }
    }
    ToolBarFrame

    测试程序10

    l 在elipse IDE中调试运行教材524页程序12-10、12-11,结合运行结果理解程序,了解GridbagLayout的用法。

    l 在elipse IDE中调试运行教材533页程序12-12,结合程序运行结果理解程序,了解GroupLayout的用法。

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package gridbag;
    
    import java.awt.EventQueue;
    
    import javax.swing.JFrame;
    
    /**
     * @version 1.35 2015-06-12
     * @author Cay Horstmann
     */
    public class GridBagLayoutTest {
        public static void main(String[] args) {
            EventQueue.invokeLater(() -> {
                JFrame frame = new FontFrame();
                frame.setTitle("GridBagLayoutTest");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            });
        }
    }
    GridBagLayoutTest
    package gridbag;
    
    import java.awt.Font;
    import java.awt.GridBagLayout;
    import java.awt.event.ActionListener;
    
    import javax.swing.BorderFactory;
    import javax.swing.JCheckBox;
    import javax.swing.JComboBox;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JTextArea;
    
    /**
     * A frame that uses a grid bag layout to arrange font selection components.
     */
    public class FontFrame extends JFrame
    {
       public static final int TEXT_ROWS = 10;
       public static final int TEXT_COLUMNS = 20;
    
       private JComboBox<String> face;
       private JComboBox<Integer> size;
       private JCheckBox bold;
       private JCheckBox italic;
       private JTextArea sample;
    
       public FontFrame()
       {
          GridBagLayout layout = new GridBagLayout();
          setLayout(layout);
    
          ActionListener listener = event -> updateSample();
    
          // 构建组件
    
          JLabel faceLabel = new JLabel("Face: ");
    
          face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced",
                "Dialog", "DialogInput" });
    
          face.addActionListener(listener);
    
          JLabel sizeLabel = new JLabel("Size: ");
    
          size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 });
    
          size.addActionListener(listener);
    
          bold = new JCheckBox("Bold");
          bold.addActionListener(listener);
    
          italic = new JCheckBox("Italic");
          italic.addActionListener(listener);
    
          sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
          sample.setText("The quick brown fox jumps over the lazy dog");
          sample.setEditable(false);
          sample.setLineWrap(true);
          sample.setBorder(BorderFactory.createEtchedBorder());
    
          // 使用GBC便利类向网格添加组件
    
          add(faceLabel, new GBC(0, 0).setAnchor(GBC.EAST));
          add(face, new GBC(1, 0).setFill(GBC.HORIZONTAL).setWeight(100, 0)
                .setInsets(1));
          add(sizeLabel, new GBC(0, 1).setAnchor(GBC.EAST));
          add(size, new GBC(1, 1).setFill(GBC.HORIZONTAL).setWeight(100, 0)
                .setInsets(1));
          add(bold, new GBC(0, 2, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100));
          add(italic, new GBC(0, 3, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100));
          add(sample, new GBC(2, 0, 1, 4).setFill(GBC.BOTH).setWeight(100, 100));
          pack();
          updateSample();
       }
    
       public void updateSample()
       {
          String fontFace = (String) face.getSelectedItem();
          int fontStyle = (bold.isSelected() ? Font.BOLD : 0)
                + (italic.isSelected() ? Font.ITALIC : 0);
          int fontSize = size.getItemAt(size.getSelectedIndex());
          Font font = new Font(fontFace, fontStyle, fontSize);
          sample.setFont(font);
          sample.repaint();
       }
    FontFrame
    package gridbag;
    
    import java.awt.*;
    
    /**
     * This class simplifies the use of the GridBagConstraints class.
     * 
     * @version 1.01 2004-05-06
     * @author Cay Horstmann
     */
    public class GBC extends GridBagConstraints {
        /**
         * Constructs a GBC with a given gridx and gridy position and all other grid bag
         * constraint values set to the default.
         * 
         * @param gridx the gridx position
         * @param gridy the gridy position
         */
        public GBC(int gridx, int gridy) {
            this.gridx = gridx;
            this.gridy = gridy;
        }
    
        /**
         * Constructs a GBC with given gridx, gridy, gridwidth, gridheight and all other
         * grid bag constraint values set to the default.
         * 
         * @param gridx      the gridx position
         * @param gridy      the gridy position
         * @param gridwidth  the cell span in x-direction
         * @param gridheight the cell span in y-direction
         */
        public GBC(int gridx, int gridy, int gridwidth, int gridheight) {
            this.gridx = gridx;
            this.gridy = gridy;
            this.gridwidth = gridwidth;
            this.gridheight = gridheight;
        }
    
        /**
         * Sets the anchor.
         * 
         * @param anchor the anchor value
         * @return this object for further modification
         */
        public GBC setAnchor(int anchor) {
            this.anchor = anchor;
            return this;
        }
    
        /**
         * Sets the fill direction.
         * 
         * @param fill the fill direction
         * @return this object for further modification
         */
        public GBC setFill(int fill) {
            this.fill = fill;
            return this;
        }
    
        /**
         * Sets the cell weights.
         * 
         * @param weightx the cell weight in x-direction
         * @param weighty the cell weight in y-direction
         * @return this object for further modification
         */
        public GBC setWeight(double weightx, double weighty) {
            this.weightx = weightx;
            this.weighty = weighty;
            return this;
        }
    
        /**
         * Sets the insets of this cell.
         * 
         * @param distance the spacing to use in all directions
         * @return this object for further modification
         */
        public GBC setInsets(int distance) {
            this.insets = new Insets(distance, distance, distance, distance);
            return this;
        }
    
        /**
         * Sets the insets of this cell.
         * 
         * @param top    the spacing to use on top
         * @param left   the spacing to use to the left
         * @param bottom the spacing to use on the bottom
         * @param right  the spacing to use to the right
         * @return this object for further modification
         */
        public GBC setInsets(int top, int left, int bottom, int right) {
            this.insets = new Insets(top, left, bottom, right);
            return this;
        }
    
        /**
         * Sets the internal padding
         * 
         * @param ipadx the internal padding in x-direction
         * @param ipady the internal padding in y-direction
         * @return this object for further modification
         */
        public GBC setIpad(int ipadx, int ipady) {
            this.ipadx = ipadx;
            this.ipady = ipady;
            return this;
        }
    }
    GBC

    package groupLayout;
    
    import java.awt.EventQueue;
    
    import javax.swing.JFrame;
    
    /**
     * @version 1.01 2015-06-12
     * @author Cay Horstmann
     */
    public class GroupLayoutTest {
        public static void main(String[] args) {
            EventQueue.invokeLater(() -> {
                JFrame frame = new FontFrame();
                frame.setTitle("GroupLayoutTest");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            });
        }
    }
    GroupLayoutTest
    package groupLayout;
    
    import java.awt.Font;
    import java.awt.event.ActionListener;
    
    import javax.swing.BorderFactory;
    import javax.swing.GroupLayout;
    import javax.swing.JCheckBox;
    import javax.swing.JComboBox;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JScrollPane;
    import javax.swing.JTextArea;
    import javax.swing.LayoutStyle;
    import javax.swing.SwingConstants;
    
    /**
     * A frame that uses a group layout to arrange font selection components.
     */
    public class FontFrame extends JFrame {
        public static final int TEXT_ROWS = 10;
        public static final int TEXT_COLUMNS = 20;
    
        private JComboBox<String> face;
        private JComboBox<Integer> size;
        private JCheckBox bold;
        private JCheckBox italic;
        private JScrollPane pane;
        private JTextArea sample;
    
        public FontFrame() {
            ActionListener listener = event -> updateSample();
    
            // construct components
    
            JLabel faceLabel = new JLabel("Face: ");
    
            face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced", "Dialog", "DialogInput" });
    
            face.addActionListener(listener);
    
            JLabel sizeLabel = new JLabel("Size: ");
    
            size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 });
    
            size.addActionListener(listener);
    
            bold = new JCheckBox("Bold");
            bold.addActionListener(listener);
    
            italic = new JCheckBox("Italic");
            italic.addActionListener(listener);
    
            sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
            sample.setText("The quick brown fox jumps over the lazy dog");
            sample.setEditable(false);
            sample.setLineWrap(true);
            sample.setBorder(BorderFactory.createEtchedBorder());
    
            pane = new JScrollPane(sample);
    
            GroupLayout layout = new GroupLayout(getContentPane());
            setLayout(layout);
            layout.setHorizontalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup().addContainerGap()
                            .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                                    .addGroup(GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                                            .addGroup(layout.createParallelGroup(GroupLayout.Alignment.TRAILING)
                                                    .addComponent(faceLabel).addComponent(sizeLabel))
                                            .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)
                                            .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING, false)
                                                    .addComponent(size).addComponent(face)))
                                    .addComponent(italic).addComponent(bold))
                            .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED).addComponent(pane).addContainerGap()));
    
            layout.linkSize(SwingConstants.HORIZONTAL, new java.awt.Component[] { face, size });
    
            layout.setVerticalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup().addContainerGap()
                            .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                                    .addComponent(pane, GroupLayout.Alignment.TRAILING)
                                    .addGroup(layout.createSequentialGroup()
                                            .addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
                                                    .addComponent(face).addComponent(faceLabel))
                                            .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)
                                            .addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
                                                    .addComponent(size).addComponent(sizeLabel))
                                            .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)
                                            .addComponent(italic, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE,
                                                    Short.MAX_VALUE)
                                            .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED).addComponent(bold,
                                                    GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
                            .addContainerGap()));
            pack();
        }
    
        public void updateSample() {
            String fontFace = (String) face.getSelectedItem();
            int fontStyle = (bold.isSelected() ? Font.BOLD : 0) + (italic.isSelected() ? Font.ITALIC : 0);
            int fontSize = size.getItemAt(size.getSelectedIndex());
            Font font = new Font(fontFace, fontStyle, fontSize);
            sample.setFont(font);
            sample.repaint();
        }
    }
    FontFrame

    测试程序11

    l 在elipse IDE中调试运行教材539页程序12-13、12-14,结合运行结果理解程序;

    l 掌握定制布局管理器的用法。

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package circleLayout;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.33 2015-06-12
     * @author Cay Horstmann
     */
    public class CircleLayoutTest {
        public static void main(String[] args) {
            EventQueue.invokeLater(() -> {
                JFrame frame = new CircleLayoutFrame();
                frame.setTitle("CircleLayoutTest");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            });
        }
    }
    CircleLayoutTest
    package circleLayout;
    
    import javax.swing.*;
    
    /**
     * A frame that shows buttons arranged along a circle.
     */
    public class CircleLayoutFrame extends JFrame {
        public CircleLayoutFrame() {
            setLayout(new CircleLayout());
            add(new JButton("Yellow"));
            add(new JButton("Blue"));
            add(new JButton("Red"));
            add(new JButton("Green"));
            add(new JButton("Orange"));
            add(new JButton("Fuchsia"));
            add(new JButton("Indigo"));
            pack();
        }
    }
    CircleLayoutFrame
    package circleLayout;
    
    import java.awt.*;
    
    /**
     * A layout manager that lays out components along a circle.
     */
    public class CircleLayout implements LayoutManager {
        private int minWidth = 0;
        private int minHeight = 0;
        private int preferredWidth = 0;
        private int preferredHeight = 0;
        private boolean sizesSet = false;
        private int maxComponentWidth = 0;
        private int maxComponentHeight = 0;
    
        public void addLayoutComponent(String name, Component comp) {
        }
    
        public void removeLayoutComponent(Component comp) {
        }
    
        public void setSizes(Container parent) {
            if (sizesSet)
                return;
            int n = parent.getComponentCount();
    
            preferredWidth = 0;
            preferredHeight = 0;
            minWidth = 0;
            minHeight = 0;
            maxComponentWidth = 0;
            maxComponentHeight = 0;
    
            // compute the maximum component widths and heights
            // and set the preferred size to the sum of the component sizes.
            for (int i = 0; i < n; i++) {
                Component c = parent.getComponent(i);
                if (c.isVisible()) {
                    Dimension d = c.getPreferredSize();
                    maxComponentWidth = Math.max(maxComponentWidth, d.width);
                    maxComponentHeight = Math.max(maxComponentHeight, d.height);
                    preferredWidth += d.width;
                    preferredHeight += d.height;
                }
            }
            minWidth = preferredWidth / 2;
            minHeight = preferredHeight / 2;
            sizesSet = true;
        }
    
        public Dimension preferredLayoutSize(Container parent) {
            setSizes(parent);
            Insets insets = parent.getInsets();
            int width = preferredWidth + insets.left + insets.right;
            int height = preferredHeight + insets.top + insets.bottom;
            return new Dimension(width, height);
        }
    
        public Dimension minimumLayoutSize(Container parent) {
            setSizes(parent);
            Insets insets = parent.getInsets();
            int width = minWidth + insets.left + insets.right;
            int height = minHeight + insets.top + insets.bottom;
            return new Dimension(width, height);
        }
    
        public void layoutContainer(Container parent) {
            setSizes(parent);
    
            // compute center of the circle
    
            Insets insets = parent.getInsets();
            int containerWidth = parent.getSize().width - insets.left - insets.right;
            int containerHeight = parent.getSize().height - insets.top - insets.bottom;
    
            int xcenter = insets.left + containerWidth / 2;
            int ycenter = insets.top + containerHeight / 2;
    
            // compute radius of the circle
    
            int xradius = (containerWidth - maxComponentWidth) / 2;
            int yradius = (containerHeight - maxComponentHeight) / 2;
            int radius = Math.min(xradius, yradius);
    
            // lay out components along the circle
    
            int n = parent.getComponentCount();
            for (int i = 0; i < n; i++) {
                Component c = parent.getComponent(i);
                if (c.isVisible()) {
                    double angle = 2 * Math.PI * i / n;
    
                    // center point of component
                    int x = xcenter + (int) (Math.cos(angle) * radius);
                    int y = ycenter + (int) (Math.sin(angle) * radius);
    
                    // move component so that its center is (x, y)
                    // and its size is its preferred size
                    Dimension d = c.getPreferredSize();
                    c.setBounds(x - d.width / 2, y - d.height / 2, d.width, d.height);
                }
            }
        }
    }
    CircleLayout

    测试程序12

    l 在elipse IDE中调试运行教材544页程序12-15、12-16,结合运行结果理解程序;

    l 掌握选项对话框的用法。

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package optionDialog;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.34 2015-06-12
     * @author Cay Horstmann
     */
    public class OptionDialogTest {
        public static void main(String[] args) {
            EventQueue.invokeLater(() -> {
                JFrame frame = new OptionDialogFrame();
                frame.setTitle("OptionDialogTest");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            });
        }
    }
    OptionDialogTest
    package optionDialog;
    
    import java.awt.*;
    import java.awt.event.*;
    import java.awt.geom.*;
    import java.util.*;
    import javax.swing.*;
    
    /**
     * A frame that contains settings for selecting various option dialogs.
     */
    public class OptionDialogFrame extends JFrame {
        private ButtonPanel typePanel;
        private ButtonPanel messagePanel;
        private ButtonPanel messageTypePanel;
        private ButtonPanel optionTypePanel;
        private ButtonPanel optionsPanel;
        private ButtonPanel inputPanel;
        private String messageString = "Message";
        private Icon messageIcon = new ImageIcon("blue-ball.gif");
        private Object messageObject = new Date();
        private Component messageComponent = new SampleComponent();
    
        public OptionDialogFrame() {
            JPanel gridPanel = new JPanel();
            gridPanel.setLayout(new GridLayout(2, 3));//创建2行3列的网格布局
    
            typePanel = new ButtonPanel("Type", "Message", "Confirm", "Option", "Input");
            messageTypePanel = new ButtonPanel("Message Type", "ERROR_MESSAGE", "INFORMATION_MESSAGE", "WARNING_MESSAGE",
                    "QUESTION_MESSAGE", "PLAIN_MESSAGE");
            messagePanel = new ButtonPanel("Message", "String", "Icon", "Component", "Other", "Object[]");
            optionTypePanel = new ButtonPanel("Confirm", "DEFAULT_OPTION", "YES_NO_OPTION", "YES_NO_CANCEL_OPTION",
                    "OK_CANCEL_OPTION");
            optionsPanel = new ButtonPanel("Option", "String[]", "Icon[]", "Object[]");
            inputPanel = new ButtonPanel("Input", "Text field", "Combo box");
    
            gridPanel.add(typePanel);
            gridPanel.add(messageTypePanel);
            gridPanel.add(messagePanel);
            gridPanel.add(optionTypePanel);
            gridPanel.add(optionsPanel);
            gridPanel.add(inputPanel);//添加按钮
    
            // add a panel with a Show button
    
            JPanel showPanel = new JPanel();
            JButton showButton = new JButton("Show");//创建一个带"Show"的按钮。
            showButton.addActionListener(new ShowAction());
            showPanel.add(showButton);
    
            add(gridPanel, BorderLayout.CENTER);//中间区域的布局约束(容器中央)。
            add(showPanel, BorderLayout.SOUTH);//南区域的布局约束(容器底部)。
            pack();
        }
    
        /**
         * Gets the currently selected message.
         * 
         * @return a string, icon, component, or object array, depending on the Message
         *         panel selection
         */
        public Object getMessage() {
            String s = messagePanel.getSelection();
            if (s.equals("String"))//将此字符串与指定的对象比较
                return messageString;
            else if (s.equals("Icon"))
                return messageIcon;
            else if (s.equals("Component"))
                return messageComponent;
            else if (s.equals("Object[]"))
                return new Object[] { messageString, messageIcon, messageComponent, messageObject };
            else if (s.equals("Other"))
                return messageObject;
            else
                return null;
        }
    
        /**
         * Gets the currently selected options.
         * 
         * @return an array of strings, icons, or objects, depending on the Option panel
         *         selection
         */
        public Object[] getOptions() {
            String s = optionsPanel.getSelection();
            if (s.equals("String[]"))
                return new String[] { "Yellow", "Blue", "Red" };
            else if (s.equals("Icon[]"))
                return new Icon[] { new ImageIcon("yellow-ball.gif"), new ImageIcon("blue-ball.gif"),
                        new ImageIcon("red-ball.gif") };
            else if (s.equals("Object[]"))
                return new Object[] { messageString, messageIcon, messageComponent, messageObject };
            else
                return null;
        }
    
        /**
         * Gets the selected message or option type
         * 
         * @param panel the Message Type or Confirm panel
         * @return the selected XXX_MESSAGE or XXX_OPTION constant from the JOptionPane
         *         class
         */
        public int getType(ButtonPanel panel) {
            String s = panel.getSelection();
            try {
                return JOptionPane.class.getField(s).getInt(null);
            } catch (Exception e) {
                return -1;
            }
        }
    
        /**
         * The action listener for the Show button shows a Confirm, Input, Message, or
         * Option dialog depending on the Type panel selection.
         */
        private class ShowAction implements ActionListener {
            public void actionPerformed(ActionEvent event) {
                if (typePanel.getSelection().equals("Confirm"))
                    JOptionPane.showConfirmDialog(OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
                            getType(messageTypePanel));
                else if (typePanel.getSelection().equals("Input")) {
                    if (inputPanel.getSelection().equals("Text field"))
                        JOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(), "Title",
                                getType(messageTypePanel));
                    else
                        JOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(), "Title",
                                getType(messageTypePanel), null, new String[] { "Yellow", "Blue", "Red" }, "Blue");
                } else if (typePanel.getSelection().equals("Message"))
                    JOptionPane.showMessageDialog(OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));
                else if (typePanel.getSelection().equals("Option"))
                    JOptionPane.showOptionDialog(OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
                            getType(messageTypePanel), null, getOptions(), getOptions()[0]);
            }
        }
    }
    
    /**
     * A component with a painted surface
     */
    
    class SampleComponent extends JComponent {
        public void paintComponent(Graphics g) {
            Graphics2D g2 = (Graphics2D) g;
            Rectangle2D rect = new Rectangle2D.Double(0, 0, getWidth() - 1, getHeight() - 1);//根据指定的 double 坐标构造和初始化 Rectangle2D
            g2.setPaint(Color.YELLOW);
            g2.fill(rect);
            g2.setPaint(Color.BLUE);
            g2.draw(rect);
        }
    
        public Dimension getPreferredSize() {
            return new Dimension(10, 10);//构造一个 Dimension,并将其初始化为指定宽度和高度。
        }
    }
    OptionDialogFrame
    package optionDialog;
    
    import javax.swing.*;
    
    /**
     * A panel with radio buttons inside a titled border.
     */
    public class ButtonPanel extends JPanel {
        private ButtonGroup group;
    
        /**
         * Constructs a button panel.
         * 
         * @param title   the title shown in the border
         * @param options an array of radio button labels
         */
        public ButtonPanel(String title, String... options) {
            setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), title));//设置组件的边框,向现有边框添加一个标题
            setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));//从上到下垂直布置组件
            group = new ButtonGroup();
    
            // make one radio button for each option
            for (String option : options) {
                JRadioButton b = new JRadioButton(option);//创建一个具有指定文本的状态为未选择的单选按钮
                b.setActionCommand(option);//设置此按钮的动作命令
                add(b);
                group.add(b);//将按钮添加到组中
                b.setSelected(option == options[0]);//设置按钮的状态
            }
        }
    
        /**
         * Gets the currently selected option.
         * 
         * @return the label of the currently selected radio button.
         */
        public String getSelection() {
            return group.getSelection().getActionCommand();//返回该按钮的动作命令字符串
        }
    }
    ButtonPanel

    测试程序13

    l 在elipse IDE中调试运行教材552页程序12-17、12-18,结合运行结果理解程序;

    l 掌握对话框的创建方法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    第十三小组负责的部分

    package dialog;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.34 2012-06-12
     * @author Cay Horstmann
     */
    public class DialogTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             JFrame frame = new DialogFrame();
             frame.setTitle("DialogTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    DialogTest
    package dialog;
    
    import javax.swing.JFrame;
    import javax.swing.JMenu;
    import javax.swing.JMenuBar;
    import javax.swing.JMenuItem;
    
    /**
     * A frame with a menu whose File->About action shows a dialog.
     */
    public class DialogFrame extends JFrame
    {
       private static final int DEFAULT_WIDTH = 300;
       private static final int DEFAULT_HEIGHT = 200;
       private AboutDialog dialog;
    
       public DialogFrame()
       {
          setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
    
          // Construct a File menu.
    
          JMenuBar menuBar = new JMenuBar();//菜单栏的实现
          setJMenuBar(menuBar);//设置此窗体的菜单栏
          JMenu fileMenu = new JMenu("File");//菜单的该实现是一个包含 JMenuItem 的弹出窗口,用户选择 JMenuBar 上的项时会显示该 JMenuItem。
          menuBar.add(fileMenu);//将指定的菜单追加到菜单栏的末尾
    
          // Add About and Exit menu items.
    
          // The About item shows the About dialog.
    
          JMenuItem aboutItem = new JMenuItem("About");//菜单中的项的实现
          aboutItem.addActionListener(event -> {
             if (dialog == null) // first time
                dialog = new AboutDialog(DialogFrame.this);
             dialog.setVisible(true); // 设置是否可见
          });
          fileMenu.add(aboutItem);//将某个菜单项追加到此菜单的末尾。返回添加的菜单项
    
          // The Exit item exits the program.
    
          JMenuItem exitItem = new JMenuItem("Exit");
          exitItem.addActionListener(event -> System.exit(0));
          fileMenu.add(exitItem);
       }
    }
    DialogFrame
    package dialog;
    
    import java.awt.BorderLayout;
    
    import javax.swing.JButton;
    import javax.swing.JDialog;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JPanel;
    
    /**
     * A sample modal dialog that displays a message and waits for the user to click the OK button.
     */
    public class AboutDialog extends JDialog
    {
        //创建一个具有指定标题、所有者 Frame 和模式的对话框。如果 owner 为 null,则一个共享的、隐藏的窗体将被设置为该对话框的所有者。
       public AboutDialog(JFrame owner)
       {
          super(owner, "About DialogTest", true);
    
          // add HTML label to center
    //将指定的组件添加到此容器的尾部
          add(
                new JLabel(
                      "<html><h1><i>Core Java</i></h1><hr>By Cay Horstmann</html>"),
                BorderLayout.CENTER);
    
          // OK button closes the dialog
    
          JButton ok = new JButton("OK");//创建一个新的按钮
          ok.addActionListener(event -> setVisible(false));
    
          // add OK button to southern border
    
          JPanel panel = new JPanel();
          panel.add(ok);
          add(panel, BorderLayout.SOUTH);//边框布局,显示在下边
    
          pack();
       }
    }
    AboutDialog

    点击File会出现About和Exit

    点击About后出现如下界面

    点击Exit后,程序退出

    测试程序14

    l 在elipse IDE中调试运行教材556页程序12-19、12-20,结合运行结果理解程序;

    l 掌握对话框的数据交换用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package dataExchange;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.34 2015-06-12
     * @author Cay Horstmann
     */
    public class DataExchangeTest {
        public static void main(String[] args) {
            EventQueue.invokeLater(() -> {
                JFrame frame = new DataExchangeFrame();
                frame.setTitle("DataExchangeTest");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            });
        }
    }
    DataExchangeTest
    package dataExchange;
    
    /**
     * A user has a name and password. For security reasons, the password is stored
     * as a char[], not a String.
     */
    public class User {
        private String name;
        private char[] password;
    
        public User(String aName, char[] aPassword) {
            name = aName;
            password = aPassword;
        }
    
        public String getName() {
            return name;
        }
    
        public char[] getPassword() {
            return password;
        }
    
        public void setName(String aName) {
            name = aName;
        }
    
        public void setPassword(char[] aPassword) {
            password = aPassword;
        }
    }
    User
    package dataExchange;
    
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    
    /**
     * A frame with a menu whose File->Connect action shows a password dialog.
     */
    public class DataExchangeFrame extends JFrame {
        public static final int TEXT_ROWS = 20;
        public static final int TEXT_COLUMNS = 40;
        private PasswordChooser dialog = null;
        private JTextArea textArea;
    
        public DataExchangeFrame() {
            // construct a File menu
    
            JMenuBar mbar = new JMenuBar();
            setJMenuBar(mbar);
            JMenu fileMenu = new JMenu("File");
            mbar.add(fileMenu);
    
            // add Connect and Exit menu items
    
            JMenuItem connectItem = new JMenuItem("Connect");
            connectItem.addActionListener(new ConnectAction());
            fileMenu.add(connectItem);
    
            // The Exit item exits the program
    
            JMenuItem exitItem = new JMenuItem("Exit");
            exitItem.addActionListener(event -> System.exit(0));
            fileMenu.add(exitItem);
    
            textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
            add(new JScrollPane(textArea), BorderLayout.CENTER);
            pack();
        }
    
        /**
         * The Connect action pops up the password dialog.
         */
        private class ConnectAction implements ActionListener {
            public void actionPerformed(ActionEvent event) {
                // if first time, construct dialog
    
                if (dialog == null)
                    dialog = new PasswordChooser();
    
                // set default values
                dialog.setUser(new User("yourname", null));
    
                // pop up dialog
                if (dialog.showDialog(DataExchangeFrame.this, "Connect")) {
                    // if accepted, retrieve user input
                    User u = dialog.getUser();
                    textArea.append("user name = " + u.getName() + ", password = " + (new String(u.getPassword())) + "
    ");
                }
            }
        }
    }
    DataExchangeFrame
    package dataExchange;
    
    import java.awt.BorderLayout;
    import java.awt.Component;
    import java.awt.Frame;
    import java.awt.GridLayout;
    
    import javax.swing.JButton;
    import javax.swing.JDialog;
    import javax.swing.JLabel;
    import javax.swing.JPanel;
    import javax.swing.JPasswordField;
    import javax.swing.JTextField;
    import javax.swing.SwingUtilities;
    
    /**
     * A password chooser that is shown inside a dialog
     */
    public class PasswordChooser extends JPanel {
        private JTextField username;
        private JPasswordField password;
        private JButton okButton;
        private boolean ok;
        private JDialog dialog;
    
        public PasswordChooser() {
            setLayout(new BorderLayout());
    
            // construct a panel with user name and password fields
    
            JPanel panel = new JPanel();
            panel.setLayout(new GridLayout(2, 2));
            panel.add(new JLabel("User name:"));
            panel.add(username = new JTextField(""));
            panel.add(new JLabel("Password:"));
            panel.add(password = new JPasswordField(""));
            add(panel, BorderLayout.CENTER);
    
            // create Ok and Cancel buttons that terminate the dialog
    
            okButton = new JButton("Ok");
            okButton.addActionListener(event -> {
                ok = true;
                dialog.setVisible(false);
            });
    
            JButton cancelButton = new JButton("Cancel");
            cancelButton.addActionListener(event -> dialog.setVisible(false));
    
            // add buttons to southern border
    
            JPanel buttonPanel = new JPanel();
            buttonPanel.add(okButton);
            buttonPanel.add(cancelButton);
            add(buttonPanel, BorderLayout.SOUTH);
        }
    
        /**
         * Sets the dialog defaults.
         * 
         * @param u the default user information
         */
        public void setUser(User u) {
            username.setText(u.getName());
        }
    
        /**
         * Gets the dialog entries.
         * 
         * @return a User object whose state represents the dialog entries
         */
        public User getUser() {
            return new User(username.getText(), password.getPassword());
        }
    
        /**
         * Show the chooser panel in a dialog
         * 
         * @param parent a component in the owner frame or null
         * @param title  the dialog window title
         */
        public boolean showDialog(Component parent, String title) {
            ok = false;
    
            // locate the owner frame
    
            Frame owner = null;
            if (parent instanceof Frame)
                owner = (Frame) parent;
            else
                owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);
    
            // if first time, or if owner has changed, make new dialog
    
            if (dialog == null || dialog.getOwner() != owner) {
                dialog = new JDialog(owner, true);
                dialog.add(this);
                dialog.getRootPane().setDefaultButton(okButton);
                dialog.pack();
            }
    
            // set title and show dialog
    
            dialog.setTitle(title);
            dialog.setVisible(true);
            return ok;
        }
    }
    PasswordChooser

    测试程序15

    l 在elipse IDE中调试运行教材556页程序12-21、12-2212-23,结合程序运行结果理解程序;

    l 掌握文件对话框的用法;

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package fileChooser;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.25 2015-06-12
     * @author Cay Horstmann
     */
    public class FileChooserTest {
        public static void main(String[] args) {
            EventQueue.invokeLater(() -> {
                JFrame frame = new ImageViewerFrame();
                frame.setTitle("FileChooserTest");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            });
        }
    }
    FileChooserTest
    package fileChooser;
    
    import java.io.*;
    import javax.swing.*;
    import javax.swing.filechooser.*;
    import javax.swing.filechooser.FileFilter;
    
    /**
     * A file view that displays an icon for all files that match a file filter.
     */
    public class FileIconView extends FileView {
        private FileFilter filter;
        private Icon icon;
    
        /**
         * Constructs a FileIconView.
         * 
         * @param aFilter a file filter--all files that this filter accepts will be
         *                shown with the icon.
         * @param         anIcon--the icon shown with all accepted files.
         */
        public FileIconView(FileFilter aFilter, Icon anIcon) {
            filter = aFilter;
            icon = anIcon;
        }
    
        public Icon getIcon(File f) {
            if (!f.isDirectory() && filter.accept(f))
                return icon;
            else
                return null;
        }
    }
    FileIconView
    package fileChooser;
    
    import java.awt.*;
    import java.io.*;
    
    import javax.swing.*;
    
    /**
     * A file chooser accessory that previews images.
     */
    public class ImagePreviewer extends JLabel {
        /**
         * Constructs an ImagePreviewer.
         * 
         * @param chooser the file chooser whose property changes trigger an image
         *                change in this previewer
         */
        public ImagePreviewer(JFileChooser chooser) {
            setPreferredSize(new Dimension(100, 100));
            setBorder(BorderFactory.createEtchedBorder());
    
            chooser.addPropertyChangeListener(event -> {
                if (event.getPropertyName() == JFileChooser.SELECTED_FILE_CHANGED_PROPERTY) {
                    // the user has selected a new file
                    File f = (File) event.getNewValue();
                    if (f == null) {
                        setIcon(null);
                        return;
                    }
    
                    // read the image into an icon
                    ImageIcon icon = new ImageIcon(f.getPath());
    
                    // if the icon is too large to fit, scale it
                    if (icon.getIconWidth() > getWidth())
                        icon = new ImageIcon(icon.getImage().getScaledInstance(getWidth(), -1, Image.SCALE_DEFAULT));
    
                    setIcon(icon);
                }
            });
        }
    }
    ImagePreviewer
    package fileChooser;
    
    import java.io.*;
    
    import javax.swing.*;
    import javax.swing.filechooser.*;
    import javax.swing.filechooser.FileFilter;
    
    /**
     * A frame that has a menu for loading an image and a display area for the
     * loaded image.
     */
    public class ImageViewerFrame extends JFrame {
        private static final int DEFAULT_WIDTH = 300;
        private static final int DEFAULT_HEIGHT = 400;
        private JLabel label;
        private JFileChooser chooser;
    
        public ImageViewerFrame() {
            setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
    
            // set up menu bar
            JMenuBar menuBar = new JMenuBar();
            setJMenuBar(menuBar);
    
            JMenu menu = new JMenu("File");
            menuBar.add(menu);
    
            JMenuItem openItem = new JMenuItem("Open");
            menu.add(openItem);
            openItem.addActionListener(event -> {
                chooser.setCurrentDirectory(new File("."));
    
                // show file chooser dialog
                int result = chooser.showOpenDialog(ImageViewerFrame.this);
    
                // if image file accepted, set it as icon of the label
                if (result == JFileChooser.APPROVE_OPTION) {
                    String name = chooser.getSelectedFile().getPath();
                    label.setIcon(new ImageIcon(name));
                    pack();
                }
            });
    
            JMenuItem exitItem = new JMenuItem("Exit");
            menu.add(exitItem);
            exitItem.addActionListener(event -> System.exit(0));
    
            // use a label to display the images
            label = new JLabel();
            add(label);
    
            // set up file chooser
            chooser = new JFileChooser();
    
            // accept all image files ending with .jpg, .jpeg, .gif
            FileFilter filter = new FileNameExtensionFilter("Image files", "jpg", "jpeg", "gif");
            chooser.setFileFilter(filter);
    
            chooser.setAccessory(new ImagePreviewer(chooser));
    
            chooser.setFileView(new FileIconView(filter, new ImageIcon("palette.gif")));
        }
    }
    ImageViewerFrame

    测试程序16

    l 在elipse IDE中调试运行教材570页程序12-24,结合运行结果理解程序;

    l 了解颜色选择器的用法。

    l 记录示例代码阅读理解中存在的问题与疑惑。

    package colorChooser;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.04 2015-06-12
     * @author Cay Horstmann
     */
    public class ColorChooserTest {
        public static void main(String[] args) {
            EventQueue.invokeLater(() -> {
                JFrame frame = new ColorChooserFrame();
                frame.setTitle("ColorChooserTest");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            });
        }
    }
    ColorChooserTest
    package colorChooser;
    
    import javax.swing.*;
    
    /**
     * A frame with a color chooser panel
     */
    public class ColorChooserFrame extends JFrame {
        private static final int DEFAULT_WIDTH = 300;
        private static final int DEFAULT_HEIGHT = 200;
    
        public ColorChooserFrame() {
            setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
    
            // add color chooser panel to frame
    
            ColorChooserPanel panel = new ColorChooserPanel();
            add(panel);
        }
    }
    ColorChooserFrame
    package colorChooser;
    
    import java.awt.Color;
    import java.awt.Frame;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    
    import javax.swing.JButton;
    import javax.swing.JColorChooser;
    import javax.swing.JDialog;
    import javax.swing.JPanel;
    
    /**
     * A panel with buttons to pop up three types of color choosers
     */
    public class ColorChooserPanel extends JPanel {
        public ColorChooserPanel() {
            JButton modalButton = new JButton("Modal");
            modalButton.addActionListener(new ModalListener());
            add(modalButton);
    
            JButton modelessButton = new JButton("Modeless");
            modelessButton.addActionListener(new ModelessListener());
            add(modelessButton);
    
            JButton immediateButton = new JButton("Immediate");
            immediateButton.addActionListener(new ImmediateListener());
            add(immediateButton);
        }
    
        /**
         * This listener pops up a modal color chooser
         */
        private class ModalListener implements ActionListener {
            public void actionPerformed(ActionEvent event) {
                Color defaultColor = getBackground();
                Color selected = JColorChooser.showDialog(ColorChooserPanel.this, "Set background", defaultColor);
                if (selected != null)
                    setBackground(selected);
            }
        }
    
        /**
         * This listener pops up a modeless color chooser. The panel color is changed
         * when the user clicks the OK button.
         */
        private class ModelessListener implements ActionListener {
            private JDialog dialog;
            private JColorChooser chooser;
    
            public ModelessListener() {
                chooser = new JColorChooser();
                dialog = JColorChooser.createDialog(ColorChooserPanel.this, "Background Color", false /* not modal */,
                        chooser, event -> setBackground(chooser.getColor()), null /* no Cancel button listener */);
            }
    
            public void actionPerformed(ActionEvent event) {
                chooser.setColor(getBackground());
                dialog.setVisible(true);
            }
        }
    
        /**
         * This listener pops up a modeless color chooser. The panel color is changed
         * immediately when the user picks a new color.
         */
        private class ImmediateListener implements ActionListener {
            private JDialog dialog;
            private JColorChooser chooser;
    
            public ImmediateListener() {
                chooser = new JColorChooser();
                chooser.getSelectionModel().addChangeListener(event -> setBackground(chooser.getColor()));
    
                dialog = new JDialog((Frame) null, false /* not modal */);
                dialog.add(chooser);
                dialog.pack();
            }
    
            public void actionPerformed(ActionEvent event) {
                chooser.setColor(getBackground());
                dialog.setVisible(true);
            }
        }
    }
    ColorChooserPanel

    实验2:组内讨论反思本组负责程序,理解程序总体结构,梳理程序GUI设计中应用的相关组件,整理相关组件的API,对程序中组件应用的相关代码添加注释。

    实验3:组间协同学习:在本班课程QQ群内,各位同学对实验1中存在的问题进行提问,提问时注明实验1中的测试程序编号,负责对应程序的小组需及时对群内提问进行回答。

    3.实验总结:

    本章的学习容量还是比较多的,就示例程序来说有十几个,在分组学习的情况下,学习相对轻松了不少,简单的来说,这种分小组学习的方式还是不错的。在本周的学习中,我学到了5中布局管理器:流式布局管理器、边框布局管理器、网格布局管理器、网格组布局管理器、卡片布局管理器。

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  • 原文地址:https://www.cnblogs.com/litinghua/p/10054085.html
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