李清华 201772020113《面向对象程序设计(java)》第十四周学习总结
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;
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1 package calculator; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class Calculator 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 CalculatorFrame frame = new CalculatorFrame(); 16 frame.setTitle("Calculator"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package calculator; 2 3 import javax.swing.*; 4 5 /** 6 * 一个带有计算器面板的框架。 7 */ 8 public class CalculatorFrame extends JFrame 9 { 10 public CalculatorFrame() 11 { 12 add(new CalculatorPanel()); 13 pack(); 14 } 15 }
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1 package calculator; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * 具有计算器按钮和结果显示的面板。 9 */ 10 public class CalculatorPanel extends JPanel 11 { 12 private JButton display; 13 private JPanel panel; 14 private double result; 15 private String lastCommand; 16 private boolean start; 17 18 public CalculatorPanel() 19 { 20 //为容器设置边框布局管理器 21 setLayout(new BorderLayout()); 22 23 result = 0; 24 lastCommand = "="; 25 start = true; 26 27 // 添加页面显示 28 29 display = new JButton("0"); 30 display.setEnabled(false); 31 add(display, BorderLayout.NORTH); 32 33 ActionListener insert = new InsertAction(); 34 ActionListener command = new CommandAction(); 35 36 // 在4×4网格中添加按钮 37 38 panel = new JPanel(); 39 panel.setLayout(new GridLayout(4, 4)); 40 41 addButton("7", insert); 42 addButton("8", insert); 43 addButton("9", insert); 44 addButton("/", command); 45 46 addButton("4", insert); 47 addButton("5", insert); 48 addButton("6", insert); 49 addButton("*", command); 50 51 addButton("1", insert); 52 addButton("2", insert); 53 addButton("3", insert); 54 addButton("-", command); 55 56 addButton("0", insert); 57 addButton(".", insert); 58 addButton("=", command); 59 addButton("+", command); 60 61 add(panel, BorderLayout.CENTER); 62 } 63 64 /** 65 * 向中心面板添加一个按钮 66 * @param 标注按钮标签 67 * @param 监听器按钮侦听器 68 */ 69 private void addButton(String label, ActionListener listener) 70 { 71 JButton button = new JButton(label); 72 button.addActionListener(listener); 73 panel.add(button); 74 } 75 76 /** 77 * 此操作将按钮操作字符串插入到显示文本的末尾 78 */ 79 private class InsertAction implements ActionListener 80 { 81 public void actionPerformed(ActionEvent event) 82 { 83 String input = event.getActionCommand(); 84 if (start) 85 { 86 display.setText(""); 87 start = false; 88 } 89 display.setText(display.getText() + input); 90 } 91 } 92 93 /** 94 * 此操作执行按钮操作字符串所表示的命令。 95 */ 96 private class CommandAction implements ActionListener 97 { 98 public void actionPerformed(ActionEvent event) 99 { 100 String command = event.getActionCommand(); 101 102 //解决了负数的输入,一旦输入“-”号就直接跳转到计算部分 103 if (start) 104 { 105 if (command.equals("-")) 106 { 107 display.setText(command); 108 start = false; 109 } 110 else lastCommand = command; 111 } 112 else 113 { 114 calculate(Double.parseDouble(display.getText())); 115 lastCommand = command; 116 start = true; 117 } 118 } 119 } 120 121 /** 122 * 执行悬而未决的计算 123 * @param x值与先前结果一起累积。 124 */ 125 public void calculate(double x) 126 { 127 if (lastCommand.equals("+")) result += x; 128 else if (lastCommand.equals("-")) result -= x; 129 else if (lastCommand.equals("*")) result *= x; 130 else if (lastCommand.equals("/")) result /= x; 131 else if (lastCommand.equals("=")) result = x; 132 display.setText("" + result);//将结果转化成字符串显示 133 } 134 }
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。
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1 package text; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.41 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class TextComponentTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new TextComponentFrame(); 16 frame.setTitle("TextComponentTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package text; 2 3 import java.awt.BorderLayout; 4 import java.awt.GridLayout; 5 6 import javax.swing.JButton; 7 import javax.swing.JFrame; 8 import javax.swing.JLabel; 9 import javax.swing.JPanel; 10 import javax.swing.JPasswordField; 11 import javax.swing.JScrollPane; 12 import javax.swing.JTextArea; 13 import javax.swing.JTextField; 14 import javax.swing.SwingConstants; 15 16 /** 17 * 具有文本文本组件的框架。 18 */ 19 public class TextComponentFrame extends JFrame 20 { 21 public static final int TEXTAREA_ROWS = 8; 22 public static final int TEXTAREA_COLUMNS = 20; 23 24 public TextComponentFrame() 25 { 26 JTextField textField = new JTextField(); 27 JPasswordField passwordField = new JPasswordField(); 28 29 JPanel northPanel = new JPanel(); 30 northPanel.setLayout(new GridLayout(2, 2)); 31 //SwingConstants通常用于在屏幕上定位或定向组件的常量的集合 32 northPanel.add(new JLabel("User name: ", SwingConstants.RIGHT)); 33 northPanel.add(textField); 34 northPanel.add(new JLabel("Password: ", SwingConstants.RIGHT)); 35 northPanel.add(passwordField); 36 37 add(northPanel, BorderLayout.NORTH); 38 //构造一个文本显示区域 39 JTextArea textArea = new JTextArea(TEXTAREA_ROWS, TEXTAREA_COLUMNS); 40 //设置一个只要超过textArea就会显示的滚动条 41 JScrollPane scrollPane = new JScrollPane(textArea); 42 43 add(scrollPane, BorderLayout.CENTER); 44 45 // 添加按钮将文本追加到文本区域 46 JPanel southPanel = new JPanel(); 47 48 JButton insertButton = new JButton("Insert"); 49 southPanel.add(insertButton); 50 insertButton.addActionListener(event -> 51 textArea.append("User name: " + textField.getText() + " Password: " 52 + new String(passwordField.getPassword()) + "\n")); 53 54 add(southPanel, BorderLayout.SOUTH); 55 pack(); 56 } 57 }
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。
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1 package checkBox; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class CheckBoxTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new CheckBoxFrame(); 16 frame.setTitle("CheckBoxTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package checkBox; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * 带有样本文本标签的框和用于选择字体的复选框 9 * attributes. 10 */ 11 public class CheckBoxFrame extends JFrame 12 { 13 private JLabel label; 14 private JCheckBox bold; 15 private JCheckBox italic; 16 private static final int FONTSIZE = 24; 17 18 public CheckBoxFrame() 19 { 20 // 添加示例文本标签 21 22 label = new JLabel("The quick brown fox jumps over the lazy dog."); 23 label.setFont(new Font("Serif", Font.BOLD, FONTSIZE)); 24 add(label, BorderLayout.CENTER); 25 26 // 此侦听器设置字体属性 27 // 到复选框状态的标签 28 29 ActionListener listener = event -> { 30 int mode = 0; 31 if (bold.isSelected()) mode += Font.BOLD; 32 if (italic.isSelected()) mode += Font.ITALIC; 33 label.setFont(new Font("Serif", mode, FONTSIZE)); 34 }; 35 36 // 添加复选框 37 38 JPanel buttonPanel = new JPanel(); 39 40 bold = new JCheckBox("Bold"); 41 bold.addActionListener(listener); 42 bold.setSelected(true); 43 buttonPanel.add(bold); 44 45 italic = new JCheckBox("Italic"); 46 italic.addActionListener(listener); 47 buttonPanel.add(italic); 48 49 add(buttonPanel, BorderLayout.SOUTH); 50 pack(); 51 } 52 }
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。
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1 package radioButton; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class RadioButtonTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new RadioButtonFrame(); 16 frame.setTitle("RadioButtonTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package radioButton; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * 带有样本文本标签和单选按钮以选择字体大小的框架。 9 */ 10 public class RadioButtonFrame extends JFrame 11 { 12 private JPanel buttonPanel; 13 private ButtonGroup group; 14 private JLabel label; 15 private static final int DEFAULT_SIZE = 36; 16 17 public RadioButtonFrame() 18 { 19 // 添加示例文本标签。 20 21 label = new JLabel("The quick brown fox jumps over the lazy dog."); 22 label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE)); 23 add(label, BorderLayout.CENTER); 24 25 // 添加单选按钮 26 buttonPanel = new JPanel(); 27 group = new ButtonGroup(); 28 29 addRadioButton("Small", 8); 30 addRadioButton("Medium", 12); 31 addRadioButton("Large", 18); 32 addRadioButton("Extra large", 36); 33 34 add(buttonPanel, BorderLayout.SOUTH); 35 pack(); 36 } 37 38 /** 39 * 添加一个设置示例文本字体大小的单选按钮。 40 * @param 命名按钮上出现的字符串 41 * @param 设置此按钮设置的字体大小 42 */ 43 public void addRadioButton(String name, int size) 44 { 45 boolean selected = size == DEFAULT_SIZE; 46 JRadioButton button = new JRadioButton(name, selected); 47 group.add(button); 48 buttonPanel.add(button); 49 50 // 此侦听器设置标签字体大小。 51 52 ActionListener listener = event -> label.setFont(new Font("Serif", Font.PLAIN, size)); 53 54 button.addActionListener(listener); 55 } 56 }
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。
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1 package border; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-13 8 * @author Cay Horstmann 9 */ 10 public class BorderTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new BorderFrame(); 16 frame.setTitle("BorderTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package border; 2 3 import java.awt.*; 4 import javax.swing.*; 5 import javax.swing.border.*; 6 7 /** 8 * 用单选按钮选择边框样式的框架。 9 */ 10 public class BorderFrame extends JFrame 11 { 12 private JPanel demoPanel; 13 private JPanel buttonPanel; 14 private ButtonGroup group; 15 16 public BorderFrame() 17 { 18 demoPanel = new JPanel(); 19 buttonPanel = new JPanel(); 20 group = new ButtonGroup(); 21 //设置不同的边框类型按钮 22 addRadioButton("Lowered bevel", BorderFactory.createLoweredBevelBorder()); 23 addRadioButton("Raised bevel", BorderFactory.createRaisedBevelBorder()); 24 addRadioButton("Etched", BorderFactory.createEtchedBorder()); 25 addRadioButton("Line", BorderFactory.createLineBorder(Color.BLUE)); 26 addRadioButton("Matte", BorderFactory.createMatteBorder(10, 10, 10, 10, Color.BLUE)); 27 addRadioButton("Empty", BorderFactory.createEmptyBorder()); 28 29 Border etched = BorderFactory.createEtchedBorder(); 30 Border titled = BorderFactory.createTitledBorder(etched, "Border types"); 31 buttonPanel.setBorder(titled); 32 33 setLayout(new GridLayout(2, 1)); 34 add(buttonPanel); 35 add(demoPanel); 36 pack(); 37 } 38 39 public void addRadioButton(String buttonName, Border b) 40 { 41 JRadioButton button = new JRadioButton(buttonName); 42 button.addActionListener(event -> demoPanel.setBorder(b)); 43 group.add(button); 44 buttonPanel.add(button); 45 } 46 }
测试程序6(本小组负责的测试程序)
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。
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1 package comboBox; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.35 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class ComboBoxTest 11 { 12 public static void main(String[] args) 13 { 14 //lambda表达式 15 EventQueue.invokeLater(() -> { 16 JFrame frame = new ComboBoxFrame();//构造frame框架对象 17 frame.setTitle("ComboBoxTest");//设置标题 18 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设置用户在此窗体上发起 "close" 时默认执行的操作。 19 frame.setVisible(true);//设置框架是否可见 20 }); 21 } 22 }
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1 package comboBox; 2 3 import java.awt.BorderLayout; 4 import java.awt.Font; 5 6 import javax.swing.JComboBox; 7 import javax.swing.JFrame; 8 import javax.swing.JLabel; 9 import javax.swing.JPanel; 10 11 /** 12 * 具有样本文本标签和选择字体面的组合框的框架。 13 * 组合框:将按钮或可编辑字段与下拉列表组合的组件。 14 * 用户可以从下拉列表中选择值,下拉列表在用户请求时显示。 15 * 如果使组合框处于可编辑状态,则组合框将包括用户可在其中键入值的可编辑字段。 16 */ 17 public class ComboBoxFrame extends JFrame 18 { 19 //设置ComboBoxFrame的私有属性 20 private JComboBox<String> faceCombo; 21 private JLabel label; 22 private static final int DEFAULT_SIZE = 24; 23 24 public ComboBoxFrame() 25 { 26 // 添加示例文本标签 27 28 label = new JLabel("The quick brown fox jumps over the lazy dog."); 29 //设置字体 30 label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE)); 31 //把字体选择按钮添加到边框布局管理器的中间 32 add(label, BorderLayout.CENTER); 33 34 // 构造组合框对象并添加项目名称 35 36 faceCombo = new JComboBox<>(); 37 //把五种字体添加到选项列表中 38 faceCombo.addItem("Serif"); 39 faceCombo.addItem("SansSerif"); 40 faceCombo.addItem("Monospaced"); 41 faceCombo.addItem("Dialog"); 42 faceCombo.addItem("DialogInput"); 43 44 // 组合框监听器将标签字体更改为所选的名称(添加监听器,使用lambda表达式) 45 46 faceCombo.addActionListener(event -> 47 //设置标签的字体 48 label.setFont( 49 //getItemAt用于返回指定索引处的列表项;getSelectedIndex用于返回当前选择的选项 50 new Font(faceCombo.getItemAt(faceCombo.getSelectedIndex()), 51 Font.PLAIN, DEFAULT_SIZE))); 52 53 // 将组合框添加到边框边框的面板上 54 55 JPanel comboPanel = new JPanel(); 56 comboPanel.add(faceCombo); 57 add(comboPanel, BorderLayout.SOUTH); 58 pack(); 59 } 60 }
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。
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1 package slider; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.15 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class SliderTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 SliderFrame frame = new SliderFrame(); 16 frame.setTitle("SliderTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package slider; 2 3 import java.awt.*; 4 import java.util.*; 5 import javax.swing.*; 6 import javax.swing.event.*; 7 8 /** 9 * 一个具有许多滑块和文本字段的滑块值的框架。 10 */ 11 public class SliderFrame extends JFrame 12 { 13 private JPanel sliderPanel; 14 private JTextField textField; 15 private ChangeListener listener; 16 17 public SliderFrame() 18 { 19 sliderPanel = new JPanel(); 20 sliderPanel.setLayout(new GridBagLayout()); 21 22 // 所有滑块的公用侦听器 23 listener = event -> { 24 // 当滑块值改变时更新文本字段 25 JSlider source = (JSlider) event.getSource(); 26 textField.setText("" + source.getValue()); 27 }; 28 29 //添加普通滑块 30 31 JSlider slider = new JSlider(); 32 addSlider(slider, "Plain"); 33 34 // 添加有主和小蜱的滑块 35 36 slider = new JSlider(); 37 slider.setPaintTicks(true); 38 slider.setMajorTickSpacing(20); 39 slider.setMinorTickSpacing(5); 40 addSlider(slider, "Ticks"); 41 42 // 添加一个滑动到滴答的滑块 43 44 slider = new JSlider(); 45 slider.setPaintTicks(true); 46 slider.setSnapToTicks(true); 47 slider.setMajorTickSpacing(20); 48 slider.setMinorTickSpacing(5); 49 addSlider(slider, "Snap to ticks"); 50 51 // 添加没有磁道的滑块 52 53 slider = new JSlider(); 54 slider.setPaintTicks(true); 55 slider.setMajorTickSpacing(20); 56 slider.setMinorTickSpacing(5); 57 slider.setPaintTrack(false); 58 addSlider(slider, "No track"); 59 60 // 添加倒置滑块 61 62 slider = new JSlider(); 63 slider.setPaintTicks(true); 64 slider.setMajorTickSpacing(20); 65 slider.setMinorTickSpacing(5); 66 slider.setInverted(true); 67 addSlider(slider, "Inverted"); 68 69 // 添加带有数字标签的滑块 70 71 slider = new JSlider(); 72 slider.setPaintTicks(true); 73 slider.setPaintLabels(true); 74 slider.setMajorTickSpacing(20); 75 slider.setMinorTickSpacing(5); 76 addSlider(slider, "Labels"); 77 78 // 添加带有字母标签的滑块 79 80 slider = new JSlider(); 81 slider.setPaintLabels(true); 82 slider.setPaintTicks(true); 83 slider.setMajorTickSpacing(20); 84 slider.setMinorTickSpacing(5); 85 86 Dictionary<Integer, Component> labelTable = new Hashtable<>(); 87 labelTable.put(0, new JLabel("A")); 88 labelTable.put(20, new JLabel("B")); 89 labelTable.put(40, new JLabel("C")); 90 labelTable.put(60, new JLabel("D")); 91 labelTable.put(80, new JLabel("E")); 92 labelTable.put(100, new JLabel("F")); 93 94 slider.setLabelTable(labelTable); 95 addSlider(slider, "Custom labels"); 96 97 //添加带有图标标签的滑块 98 99 slider = new JSlider(); 100 slider.setPaintTicks(true); 101 slider.setPaintLabels(true); 102 slider.setSnapToTicks(true); 103 slider.setMajorTickSpacing(20); 104 slider.setMinorTickSpacing(20); 105 106 labelTable = new Hashtable<Integer, Component>(); 107 108 // 添加卡片图像 109 110 labelTable.put(0, new JLabel(new ImageIcon("nine.gif"))); 111 labelTable.put(20, new JLabel(new ImageIcon("ten.gif"))); 112 labelTable.put(40, new JLabel(new ImageIcon("jack.gif"))); 113 labelTable.put(60, new JLabel(new ImageIcon("queen.gif"))); 114 labelTable.put(80, new JLabel(new ImageIcon("king.gif"))); 115 labelTable.put(100, new JLabel(new ImageIcon("ace.gif"))); 116 117 slider.setLabelTable(labelTable); 118 addSlider(slider, "Icon labels"); 119 120 // 添加显示滑块值的文本字段 121 122 textField = new JTextField(); 123 add(sliderPanel, BorderLayout.CENTER); 124 add(textField, BorderLayout.SOUTH); 125 pack(); 126 } 127 128 /** 129 * 向滑块面板添加滑块并钩住听者 130 * @param S滑块 131 * @param 描述滑块描述 132 */ 133 public void addSlider(JSlider s, String description) 134 { 135 s.addChangeListener(listener); 136 JPanel panel = new JPanel(); 137 panel.add(s); 138 panel.add(new JLabel(description)); 139 panel.setAlignmentX(Component.LEFT_ALIGNMENT); 140 GridBagConstraints gbc = new GridBagConstraints(); 141 gbc.gridy = sliderPanel.getComponentCount(); 142 gbc.anchor = GridBagConstraints.WEST; 143 sliderPanel.add(panel, gbc); 144 } 145 }
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。
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1 package menu; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.24 2012-06-12 8 * @author Cay Horstmann 9 */ 10 public class MenuTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new MenuFrame(); 16 frame.setTitle("MenuTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package menu; 2 3 import java.awt.event.*; 4 import javax.swing.*; 5 6 /** 7 * 一个带有示例菜单栏的框架。 8 */ 9 public class MenuFrame extends JFrame 10 { 11 private static final int DEFAULT_WIDTH = 300; 12 private static final int DEFAULT_HEIGHT = 200; 13 private Action saveAction; 14 private Action saveAsAction; 15 private JCheckBoxMenuItem readonlyItem; 16 private JPopupMenu popup; 17 18 /** 19 * 将动作名称打印到Studio.OUT的示例动作。 20 */ 21 class TestAction extends AbstractAction 22 { 23 public TestAction(String name) 24 { 25 super(name); 26 } 27 28 public void actionPerformed(ActionEvent event) 29 { 30 System.out.println(getValue(Action.NAME) + " selected."); 31 } 32 } 33 34 public MenuFrame() 35 { 36 setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); 37 38 JMenu fileMenu = new JMenu("File"); 39 fileMenu.add(new TestAction("New")); 40 41 //演示加速器 42 43 JMenuItem openItem = fileMenu.add(new TestAction("Open")); 44 openItem.setAccelerator(KeyStroke.getKeyStroke("ctrl O")); 45 46 fileMenu.addSeparator(); 47 48 saveAction = new TestAction("Save"); 49 JMenuItem saveItem = fileMenu.add(saveAction); 50 saveItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S")); 51 52 saveAsAction = new TestAction("Save As"); 53 fileMenu.add(saveAsAction); 54 fileMenu.addSeparator(); 55 56 fileMenu.add(new AbstractAction("Exit") 57 { 58 public void actionPerformed(ActionEvent event) 59 { 60 System.exit(0); 61 } 62 }); 63 64 // 演示复选框和单选按钮菜单 65 66 readonlyItem = new JCheckBoxMenuItem("Read-only"); 67 readonlyItem.addActionListener(new ActionListener() 68 { 69 public void actionPerformed(ActionEvent event) 70 { 71 boolean saveOk = !readonlyItem.isSelected(); 72 saveAction.setEnabled(saveOk); 73 saveAsAction.setEnabled(saveOk); 74 } 75 }); 76 77 ButtonGroup group = new ButtonGroup(); 78 79 JRadioButtonMenuItem insertItem = new JRadioButtonMenuItem("Insert"); 80 insertItem.setSelected(true); 81 JRadioButtonMenuItem overtypeItem = new JRadioButtonMenuItem("Overtype"); 82 83 group.add(insertItem); 84 group.add(overtypeItem); 85 86 // 演示图标 87 88 Action cutAction = new TestAction("Cut"); 89 cutAction.putValue(Action.SMALL_ICON, new ImageIcon("cut.gif")); 90 Action copyAction = new TestAction("Copy"); 91 copyAction.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif")); 92 Action pasteAction = new TestAction("Paste"); 93 pasteAction.putValue(Action.SMALL_ICON, new ImageIcon("paste.gif")); 94 95 JMenu editMenu = new JMenu("Edit"); 96 editMenu.add(cutAction); 97 editMenu.add(copyAction); 98 editMenu.add(pasteAction); 99 100 // 演示嵌套菜单 101 102 JMenu optionMenu = new JMenu("Options"); 103 104 optionMenu.add(readonlyItem); 105 optionMenu.addSeparator(); 106 optionMenu.add(insertItem); 107 optionMenu.add(overtypeItem); 108 109 editMenu.addSeparator(); 110 editMenu.add(optionMenu); 111 112 // 助记符演示 113 114 JMenu helpMenu = new JMenu("Help"); 115 helpMenu.setMnemonic('H'); 116 117 JMenuItem indexItem = new JMenuItem("Index"); 118 indexItem.setMnemonic('I'); 119 helpMenu.add(indexItem); 120 121 // 还可以将助记键添加到动作中。 122 Action aboutAction = new TestAction("About"); 123 aboutAction.putValue(Action.MNEMONIC_KEY, new Integer('A')); 124 helpMenu.add(aboutAction); 125 126 //将所有顶级菜单添加到菜单栏 127 128 JMenuBar menuBar = new JMenuBar(); 129 setJMenuBar(menuBar); 130 131 menuBar.add(fileMenu); 132 menuBar.add(editMenu); 133 menuBar.add(helpMenu); 134 135 //演示弹出窗口 136 137 popup = new JPopupMenu(); 138 popup.add(cutAction); 139 popup.add(copyAction); 140 popup.add(pasteAction); 141 142 JPanel panel = new JPanel(); 143 panel.setComponentPopupMenu(popup); 144 add(panel); 145 } 146 }
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。
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1 package toolBar; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.14 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class ToolBarTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 ToolBarFrame frame = new ToolBarFrame(); 16 frame.setTitle("ToolBarTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package toolBar; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * 带有工具栏和菜单的框架,用于颜色变化。 9 */ 10 public class ToolBarFrame extends JFrame 11 { 12 private static final int DEFAULT_WIDTH = 300; 13 private static final int DEFAULT_HEIGHT = 200; 14 private JPanel panel; 15 16 public ToolBarFrame() 17 { 18 setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); 19 20 // 添加颜色变化面板 21 22 panel = new JPanel(); 23 add(panel, BorderLayout.CENTER); 24 25 // 设置动作 26 27 Action blueAction = new ColorAction("Blue", new ImageIcon("blue-ball.gif"), Color.BLUE); 28 Action yellowAction = new ColorAction("Yellow", new ImageIcon("yellow-ball.gif"), 29 Color.YELLOW); 30 Action redAction = new ColorAction("Red", new ImageIcon("red-ball.gif"), Color.RED); 31 32 Action exitAction = new AbstractAction("Exit", new ImageIcon("exit.gif")) 33 { 34 public void actionPerformed(ActionEvent event) 35 { 36 System.exit(0); 37 } 38 }; 39 exitAction.putValue(Action.SHORT_DESCRIPTION, "Exit"); 40 41 //填充工具栏 42 43 JToolBar bar = new JToolBar(); 44 bar.add(blueAction); 45 bar.add(yellowAction); 46 bar.add(redAction); 47 bar.addSeparator(); 48 bar.add(exitAction); 49 add(bar, BorderLayout.NORTH); 50 51 // 填充菜单 52 53 JMenu menu = new JMenu("Color"); 54 menu.add(yellowAction); 55 menu.add(blueAction); 56 menu.add(redAction); 57 menu.add(exitAction); 58 JMenuBar menuBar = new JMenuBar(); 59 menuBar.add(menu); 60 setJMenuBar(menuBar); 61 } 62 63 /** 64 *颜色动作将帧的背景设置为给定的颜色。 65 */ 66 class ColorAction extends AbstractAction 67 { 68 public ColorAction(String name, Icon icon, Color c) 69 { 70 putValue(Action.NAME, name); 71 putValue(Action.SMALL_ICON, icon); 72 putValue(Action.SHORT_DESCRIPTION, name + " background"); 73 putValue("Color", c); 74 } 75 76 public void actionPerformed(ActionEvent event) 77 { 78 Color c = (Color) getValue("Color"); 79 panel.setBackground(c); 80 } 81 } 82 }
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。
1.
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1 package gridbag; 2 3 import java.awt.EventQueue; 4 5 import javax.swing.JFrame; 6 7 /** 8 * @version 1.35 2015-06-12 9 * @author Cay Horstmann 10 */ 11 public class GridBagLayoutTest 12 { 13 public static void main(String[] args) 14 { 15 EventQueue.invokeLater(() -> { 16 JFrame frame = new FontFrame(); 17 frame.setTitle("GridBagLayoutTest"); 18 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 19 frame.setVisible(true); 20 }); 21 } 22 }
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1 package gridbag; 2 3 import java.awt.Font; 4 import java.awt.GridBagLayout; 5 import java.awt.event.ActionListener; 6 7 import javax.swing.BorderFactory; 8 import javax.swing.JCheckBox; 9 import javax.swing.JComboBox; 10 import javax.swing.JFrame; 11 import javax.swing.JLabel; 12 import javax.swing.JTextArea; 13 14 /** 15 * A frame that uses a grid bag layout to arrange font selection components. 16 */ 17 public class FontFrame extends JFrame 18 { 19 public static final int TEXT_ROWS = 10; 20 public static final int TEXT_COLUMNS = 20; 21 22 private JComboBox<String> face; 23 private JComboBox<Integer> size; 24 private JCheckBox bold; 25 private JCheckBox italic; 26 private JTextArea sample; 27 28 public FontFrame() 29 { 30 GridBagLayout layout = new GridBagLayout(); 31 setLayout(layout); 32 33 ActionListener listener = event -> updateSample(); 34 35 // construct components 36 37 JLabel faceLabel = new JLabel("Face: "); 38 39 face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced", 40 "Dialog", "DialogInput" }); 41 42 face.addActionListener(listener); 43 44 JLabel sizeLabel = new JLabel("Size: "); 45 46 size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 }); 47 48 size.addActionListener(listener); 49 50 bold = new JCheckBox("Bold"); 51 bold.addActionListener(listener); 52 53 italic = new JCheckBox("Italic"); 54 italic.addActionListener(listener); 55 56 sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS); 57 sample.setText("The quick brown fox jumps over the lazy dog"); 58 sample.setEditable(false); 59 sample.setLineWrap(true); 60 sample.setBorder(BorderFactory.createEtchedBorder()); 61 62 // add components to grid, using GBC convenience class 63 64 add(faceLabel, new GBC(0, 0).setAnchor(GBC.EAST)); 65 add(face, new GBC(1, 0).setFill(GBC.HORIZONTAL).setWeight(100, 0) 66 .setInsets(1)); 67 add(sizeLabel, new GBC(0, 1).setAnchor(GBC.EAST)); 68 add(size, new GBC(1, 1).setFill(GBC.HORIZONTAL).setWeight(100, 0) 69 .setInsets(1)); 70 add(bold, new GBC(0, 2, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100)); 71 add(italic, new GBC(0, 3, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100)); 72 add(sample, new GBC(2, 0, 1, 4).setFill(GBC.BOTH).setWeight(100, 100)); 73 pack(); 74 updateSample(); 75 } 76 77 public void updateSample() 78 { 79 String fontFace = (String) face.getSelectedItem(); 80 int fontStyle = (bold.isSelected() ? Font.BOLD : 0) 81 + (italic.isSelected() ? Font.ITALIC : 0); 82 int fontSize = size.getItemAt(size.getSelectedIndex()); 83 Font font = new Font(fontFace, fontStyle, fontSize); 84 sample.setFont(font); 85 sample.repaint(); 86 } 87 }
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1 package gridbag; 2 3 import java.awt.*; 4 5 /** 6 * This class simplifies the use of the GridBagConstraints class. 7 * @version 1.01 2004-05-06 8 * @author Cay Horstmann 9 */ 10 public class GBC extends GridBagConstraints 11 { 12 /** 13 * Constructs a GBC with a given gridx and gridy position and all other grid 14 * bag constraint values set to the default. 15 * @param gridx the gridx position 16 * @param gridy the gridy position 17 */ 18 public GBC(int gridx, int gridy) 19 { 20 this.gridx = gridx; 21 this.gridy = gridy; 22 } 23 24 /** 25 * Constructs a GBC with given gridx, gridy, gridwidth, gridheight and all 26 * other grid bag constraint values set to the default. 27 * @param gridx the gridx position 28 * @param gridy the gridy position 29 * @param gridwidth the cell span in x-direction 30 * @param gridheight the cell span in y-direction 31 */ 32 public GBC(int gridx, int gridy, int gridwidth, int gridheight) 33 { 34 this.gridx = gridx; 35 this.gridy = gridy; 36 this.gridwidth = gridwidth; 37 this.gridheight = gridheight; 38 } 39 40 /** 41 * Sets the anchor. 42 * @param anchor the anchor value 43 * @return this object for further modification 44 */ 45 public GBC setAnchor(int anchor) 46 { 47 this.anchor = anchor; 48 return this; 49 } 50 51 /** 52 * Sets the fill direction. 53 * @param fill the fill direction 54 * @return this object for further modification 55 */ 56 public GBC setFill(int fill) 57 { 58 this.fill = fill; 59 return this; 60 } 61 62 /** 63 * Sets the cell weights. 64 * @param weightx the cell weight in x-direction 65 * @param weighty the cell weight in y-direction 66 * @return this object for further modification 67 */ 68 public GBC setWeight(double weightx, double weighty) 69 { 70 this.weightx = weightx; 71 this.weighty = weighty; 72 return this; 73 } 74 75 /** 76 * Sets the insets of this cell. 77 * @param distance the spacing to use in all directions 78 * @return this object for further modification 79 */ 80 public GBC setInsets(int distance) 81 { 82 this.insets = new Insets(distance, distance, distance, distance); 83 return this; 84 } 85 86 /** 87 * Sets the insets of this cell. 88 * @param top the spacing to use on top 89 * @param left the spacing to use to the left 90 * @param bottom the spacing to use on the bottom 91 * @param right the spacing to use to the right 92 * @return this object for further modification 93 */ 94 public GBC setInsets(int top, int left, int bottom, int right) 95 { 96 this.insets = new Insets(top, left, bottom, right); 97 return this; 98 } 99 100 /** 101 * Sets the internal padding 102 * @param ipadx the internal padding in x-direction 103 * @param ipady the internal padding in y-direction 104 * @return this object for further modification 105 */ 106 public GBC setIpad(int ipadx, int ipady) 107 { 108 this.ipadx = ipadx; 109 this.ipady = ipady; 110 return this; 111 } 112 }
2.
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1 package groupLayout; 2 3 import java.awt.EventQueue; 4 5 import javax.swing.JFrame; 6 7 /** 8 * @version 1.01 2015-06-12 9 * @author Cay Horstmann 10 */ 11 public class GroupLayoutTest 12 { 13 public static void main(String[] args) 14 { 15 EventQueue.invokeLater(() -> { 16 JFrame frame = new FontFrame(); 17 frame.setTitle("GroupLayoutTest"); 18 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 19 frame.setVisible(true); 20 }); 21 } 22 }
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1 package groupLayout; 2 3 import java.awt.Font; 4 import java.awt.event.ActionListener; 5 6 import javax.swing.BorderFactory; 7 import javax.swing.GroupLayout; 8 import javax.swing.JCheckBox; 9 import javax.swing.JComboBox; 10 import javax.swing.JFrame; 11 import javax.swing.JLabel; 12 import javax.swing.JScrollPane; 13 import javax.swing.JTextArea; 14 import javax.swing.LayoutStyle; 15 import javax.swing.SwingConstants; 16 17 /** 18 * A frame that uses a group layout to arrange font selection components. 19 */ 20 public class FontFrame extends JFrame 21 { 22 public static final int TEXT_ROWS = 10; 23 public static final int TEXT_COLUMNS = 20; 24 25 private JComboBox<String> face; 26 private JComboBox<Integer> size; 27 private JCheckBox bold; 28 private JCheckBox italic; 29 private JScrollPane pane; 30 private JTextArea sample; 31 32 public FontFrame() 33 { 34 ActionListener listener = event -> updateSample(); 35 36 // construct components 37 38 JLabel faceLabel = new JLabel("Face: "); 39 40 face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced", "Dialog", 41 "DialogInput" }); 42 43 face.addActionListener(listener); 44 45 JLabel sizeLabel = new JLabel("Size: "); 46 47 size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 }); 48 49 size.addActionListener(listener); 50 51 bold = new JCheckBox("Bold"); 52 bold.addActionListener(listener); 53 54 italic = new JCheckBox("Italic"); 55 italic.addActionListener(listener); 56 57 sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS); 58 sample.setText("The quick brown fox jumps over the lazy dog"); 59 sample.setEditable(false); 60 sample.setLineWrap(true); 61 sample.setBorder(BorderFactory.createEtchedBorder()); 62 63 pane = new JScrollPane(sample); 64 65 GroupLayout layout = new GroupLayout(getContentPane()); 66 setLayout(layout); 67 layout.setHorizontalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING) 68 .addGroup( 69 layout.createSequentialGroup().addContainerGap().addGroup( 70 layout.createParallelGroup(GroupLayout.Alignment.LEADING).addGroup( 71 GroupLayout.Alignment.TRAILING, 72 layout.createSequentialGroup().addGroup( 73 layout.createParallelGroup(GroupLayout.Alignment.TRAILING) 74 .addComponent(faceLabel).addComponent(sizeLabel)) 75 .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED) 76 .addGroup( 77 layout.createParallelGroup( 78 GroupLayout.Alignment.LEADING, false) 79 .addComponent(size).addComponent(face))) 80 .addComponent(italic).addComponent(bold)).addPreferredGap( 81 LayoutStyle.ComponentPlacement.RELATED).addComponent(pane) 82 .addContainerGap())); 83 84 layout.linkSize(SwingConstants.HORIZONTAL, new java.awt.Component[] { face, size }); 85 86 layout.setVerticalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING) 87 .addGroup( 88 layout.createSequentialGroup().addContainerGap().addGroup( 89 layout.createParallelGroup(GroupLayout.Alignment.LEADING).addComponent( 90 pane, GroupLayout.Alignment.TRAILING).addGroup( 91 layout.createSequentialGroup().addGroup( 92 layout.createParallelGroup(GroupLayout.Alignment.BASELINE) 93 .addComponent(face).addComponent(faceLabel)) 94 .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED) 95 .addGroup( 96 layout.createParallelGroup( 97 GroupLayout.Alignment.BASELINE).addComponent(size) 98 .addComponent(sizeLabel)).addPreferredGap( 99 LayoutStyle.ComponentPlacement.RELATED).addComponent( 100 italic, GroupLayout.DEFAULT_SIZE, 101 GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) 102 .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED) 103 .addComponent(bold, GroupLayout.DEFAULT_SIZE, 104 GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))) 105 .addContainerGap())); 106 pack(); 107 } 108 109 public void updateSample() 110 { 111 String fontFace = (String) face.getSelectedItem(); 112 int fontStyle = (bold.isSelected() ? Font.BOLD : 0) 113 + (italic.isSelected() ? Font.ITALIC : 0); 114 int fontSize = size.getItemAt(size.getSelectedIndex()); 115 Font font = new Font(fontFace, fontStyle, fontSize); 116 sample.setFont(font); 117 sample.repaint(); 118 } 119 }
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。
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1 package circleLayout; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.33 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class CircleLayoutTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new CircleLayoutFrame(); 16 frame.setTitle("CircleLayoutTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package circleLayout; 2 3 import javax.swing.*; 4 5 /** 6 * A frame that shows buttons arranged along a circle. 7 */ 8 public class CircleLayoutFrame extends JFrame 9 { 10 public CircleLayoutFrame() 11 { 12 setLayout(new CircleLayout()); 13 add(new JButton("Yellow")); 14 add(new JButton("Blue")); 15 add(new JButton("Red")); 16 add(new JButton("Green")); 17 add(new JButton("Orange")); 18 add(new JButton("Fuchsia")); 19 add(new JButton("Indigo")); 20 pack(); 21 } 22 }
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1 package circleLayout; 2 3 import java.awt.*; 4 5 /** 6 * A layout manager that lays out components along a circle. 7 */ 8 public class CircleLayout implements LayoutManager 9 { 10 private int minWidth = 0; 11 private int minHeight = 0; 12 private int preferredWidth = 0; 13 private int preferredHeight = 0; 14 private boolean sizesSet = false; 15 private int maxComponentWidth = 0; 16 private int maxComponentHeight = 0; 17 18 public void addLayoutComponent(String name, Component comp) 19 { 20 } 21 22 public void removeLayoutComponent(Component comp) 23 { 24 } 25 26 public void setSizes(Container parent) 27 { 28 if (sizesSet) return; 29 int n = parent.getComponentCount(); 30 31 preferredWidth = 0; 32 preferredHeight = 0; 33 minWidth = 0; 34 minHeight = 0; 35 maxComponentWidth = 0; 36 maxComponentHeight = 0; 37 38 // compute the maximum component widths and heights 39 // and set the preferred size to the sum of the component sizes. 40 for (int i = 0; i < n; i++) 41 { 42 Component c = parent.getComponent(i); 43 if (c.isVisible()) 44 { 45 Dimension d = c.getPreferredSize(); 46 maxComponentWidth = Math.max(maxComponentWidth, d.width); 47 maxComponentHeight = Math.max(maxComponentHeight, d.height); 48 preferredWidth += d.width; 49 preferredHeight += d.height; 50 } 51 } 52 minWidth = preferredWidth / 2; 53 minHeight = preferredHeight / 2; 54 sizesSet = true; 55 } 56 57 public Dimension preferredLayoutSize(Container parent) 58 { 59 setSizes(parent); 60 Insets insets = parent.getInsets(); 61 int width = preferredWidth + insets.left + insets.right; 62 int height = preferredHeight + insets.top + insets.bottom; 63 return new Dimension(width, height); 64 } 65 66 public Dimension minimumLayoutSize(Container parent) 67 { 68 setSizes(parent); 69 Insets insets = parent.getInsets(); 70 int width = minWidth + insets.left + insets.right; 71 int height = minHeight + insets.top + insets.bottom; 72 return new Dimension(width, height); 73 } 74 75 public void layoutContainer(Container parent) 76 { 77 setSizes(parent); 78 79 // compute center of the circle 80 81 Insets insets = parent.getInsets(); 82 int containerWidth = parent.getSize().width - insets.left - insets.right; 83 int containerHeight = parent.getSize().height - insets.top - insets.bottom; 84 85 int xcenter = insets.left + containerWidth / 2; 86 int ycenter = insets.top + containerHeight / 2; 87 88 // compute radius of the circle 89 90 int xradius = (containerWidth - maxComponentWidth) / 2; 91 int yradius = (containerHeight - maxComponentHeight) / 2; 92 int radius = Math.min(xradius, yradius); 93 94 // lay out components along the circle 95 96 int n = parent.getComponentCount(); 97 for (int i = 0; i < n; i++) 98 { 99 Component c = parent.getComponent(i); 100 if (c.isVisible()) 101 { 102 double angle = 2 * Math.PI * i / n; 103 104 // center point of component 105 int x = xcenter + (int) (Math.cos(angle) * radius); 106 int y = ycenter + (int) (Math.sin(angle) * radius); 107 108 // move component so that its center is (x, y) 109 // and its size is its preferred size 110 Dimension d = c.getPreferredSize(); 111 c.setBounds(x - d.width / 2, y - d.height / 2, d.width, d.height); 112 } 113 } 114 } 115 }
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。
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1 package optionDialog; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class OptionDialogTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new OptionDialogFrame(); 16 frame.setTitle("OptionDialogTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package optionDialog; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import java.awt.geom.*; 6 import java.util.*; 7 import javax.swing.*; 8 9 /** 10 * A frame that contains settings for selecting various option dialogs. 11 */ 12 public class OptionDialogFrame extends JFrame 13 { 14 private ButtonPanel typePanel; 15 private ButtonPanel messagePanel; 16 private ButtonPanel messageTypePanel; 17 private ButtonPanel optionTypePanel; 18 private ButtonPanel optionsPanel; 19 private ButtonPanel inputPanel; 20 private String messageString = "Message"; 21 private Icon messageIcon = new ImageIcon("blue-ball.gif"); 22 private Object messageObject = new Date(); 23 private Component messageComponent = new SampleComponent(); 24 25 public OptionDialogFrame() 26 { 27 JPanel gridPanel = new JPanel(); 28 gridPanel.setLayout(new GridLayout(2, 3)); 29 30 typePanel = new ButtonPanel("Type", "Message", "Confirm", "Option", "Input"); 31 messageTypePanel = new ButtonPanel("Message Type", "ERROR_MESSAGE", "INFORMATION_MESSAGE", 32 "WARNING_MESSAGE", "QUESTION_MESSAGE", "PLAIN_MESSAGE"); 33 messagePanel = new ButtonPanel("Message", "String", "Icon", "Component", "Other", 34 "Object[]"); 35 optionTypePanel = new ButtonPanel("Confirm", "DEFAULT_OPTION", "YES_NO_OPTION", 36 "YES_NO_CANCEL_OPTION", "OK_CANCEL_OPTION"); 37 optionsPanel = new ButtonPanel("Option", "String[]", "Icon[]", "Object[]"); 38 inputPanel = new ButtonPanel("Input", "Text field", "Combo box"); 39 40 gridPanel.add(typePanel); 41 gridPanel.add(messageTypePanel); 42 gridPanel.add(messagePanel); 43 gridPanel.add(optionTypePanel); 44 gridPanel.add(optionsPanel); 45 gridPanel.add(inputPanel); 46 47 // add a panel with a Show button 48 49 JPanel showPanel = new JPanel(); 50 JButton showButton = new JButton("Show"); 51 showButton.addActionListener(new ShowAction()); 52 showPanel.add(showButton); 53 54 add(gridPanel, BorderLayout.CENTER); 55 add(showPanel, BorderLayout.SOUTH); 56 pack(); 57 } 58 59 /** 60 * Gets the currently selected message. 61 * @return a string, icon, component, or object array, depending on the Message panel selection 62 */ 63 public Object getMessage() 64 { 65 String s = messagePanel.getSelection(); 66 if (s.equals("String")) return messageString; 67 else if (s.equals("Icon")) return messageIcon; 68 else if (s.equals("Component")) return messageComponent; 69 else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon, 70 messageComponent, messageObject }; 71 else if (s.equals("Other")) return messageObject; 72 else return null; 73 } 74 75 /** 76 * Gets the currently selected options. 77 * @return an array of strings, icons, or objects, depending on the Option panel selection 78 */ 79 public Object[] getOptions() 80 { 81 String s = optionsPanel.getSelection(); 82 if (s.equals("String[]")) return new String[] { "Yellow", "Blue", "Red" }; 83 else if (s.equals("Icon[]")) return new Icon[] { new ImageIcon("yellow-ball.gif"), 84 new ImageIcon("blue-ball.gif"), new ImageIcon("red-ball.gif") }; 85 else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon, 86 messageComponent, messageObject }; 87 else return null; 88 } 89 90 /** 91 * Gets the selected message or option type 92 * @param panel the Message Type or Confirm panel 93 * @return the selected XXX_MESSAGE or XXX_OPTION constant from the JOptionPane class 94 */ 95 public int getType(ButtonPanel panel) 96 { 97 String s = panel.getSelection(); 98 try 99 { 100 return JOptionPane.class.getField(s).getInt(null); 101 } 102 catch (Exception e) 103 { 104 return -1; 105 } 106 } 107 108 /** 109 * The action listener for the Show button shows a Confirm, Input, Message, or Option dialog 110 * depending on the Type panel selection. 111 */ 112 private class ShowAction implements ActionListener 113 { 114 public void actionPerformed(ActionEvent event) 115 { 116 if (typePanel.getSelection().equals("Confirm")) JOptionPane.showConfirmDialog( 117 OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel), 118 getType(messageTypePanel)); 119 else if (typePanel.getSelection().equals("Input")) 120 { 121 if (inputPanel.getSelection().equals("Text field")) JOptionPane.showInputDialog( 122 OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel)); 123 else JOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(), "Title", 124 getType(messageTypePanel), null, new String[] { "Yellow", "Blue", "Red" }, 125 "Blue"); 126 } 127 else if (typePanel.getSelection().equals("Message")) JOptionPane.showMessageDialog( 128 OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel)); 129 else if (typePanel.getSelection().equals("Option")) JOptionPane.showOptionDialog( 130 OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel), 131 getType(messageTypePanel), null, getOptions(), getOptions()[0]); 132 } 133 } 134 } 135 136 /** 137 * A component with a painted surface 138 */ 139 140 class SampleComponent extends JComponent 141 { 142 public void paintComponent(Graphics g) 143 { 144 Graphics2D g2 = (Graphics2D) g; 145 Rectangle2D rect = new Rectangle2D.Double(0, 0, getWidth() - 1, getHeight() - 1); 146 g2.setPaint(Color.YELLOW); 147 g2.fill(rect); 148 g2.setPaint(Color.BLUE); 149 g2.draw(rect); 150 } 151 152 public Dimension getPreferredSize() 153 { 154 return new Dimension(10, 10); 155 } 156 }
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1 package optionDialog; 2 3 import javax.swing.*; 4 5 /** 6 * A panel with radio buttons inside a titled border. 7 */ 8 public class ButtonPanel extends JPanel 9 { 10 private ButtonGroup group; 11 12 /** 13 * Constructs a button panel. 14 * @param title the title shown in the border 15 * @param options an array of radio button labels 16 */ 17 public ButtonPanel(String title, String... options) 18 { 19 setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), title)); 20 setLayout(new BoxLayout(this, BoxLayout.Y_AXIS)); 21 group = new ButtonGroup(); 22 23 // make one radio button for each option 24 for (String option : options) 25 { 26 JRadioButton b = new JRadioButton(option); 27 b.setActionCommand(option); 28 add(b); 29 group.add(b); 30 b.setSelected(option == options[0]); 31 } 32 } 33 34 /** 35 * Gets the currently selected option. 36 * @return the label of the currently selected radio button. 37 */ 38 public String getSelection() 39 { 40 return group.getSelection().getActionCommand(); 41 } 42 }
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。
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1 package dialog; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2012-06-12 8 * @author Cay Horstmann 9 */ 10 public class DialogTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new DialogFrame(); 16 frame.setTitle("DialogTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package dialog; 2 3 import javax.swing.JFrame; 4 import javax.swing.JMenu; 5 import javax.swing.JMenuBar; 6 import javax.swing.JMenuItem; 7 8 /** 9 * A frame with a menu whose File->About action shows a dialog. 10 */ 11 public class DialogFrame extends JFrame 12 { 13 private static final int DEFAULT_WIDTH = 300; 14 private static final int DEFAULT_HEIGHT = 200; 15 private AboutDialog dialog; 16 17 public DialogFrame() 18 { 19 setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); 20 21 // Construct a File menu. 22 23 JMenuBar menuBar = new JMenuBar(); 24 setJMenuBar(menuBar); 25 JMenu fileMenu = new JMenu("File"); 26 menuBar.add(fileMenu); 27 28 // Add About and Exit menu items. 29 30 // The About item shows the About dialog. 31 32 JMenuItem aboutItem = new JMenuItem("About"); 33 aboutItem.addActionListener(event -> { 34 if (dialog == null) // first time 35 dialog = new AboutDialog(DialogFrame.this); 36 dialog.setVisible(true); // pop up dialog 37 }); 38 fileMenu.add(aboutItem); 39 40 // The Exit item exits the program. 41 42 JMenuItem exitItem = new JMenuItem("Exit"); 43 exitItem.addActionListener(event -> System.exit(0)); 44 fileMenu.add(exitItem); 45 } 46 }
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1 package dialog; 2 3 import java.awt.BorderLayout; 4 5 import javax.swing.JButton; 6 import javax.swing.JDialog; 7 import javax.swing.JFrame; 8 import javax.swing.JLabel; 9 import javax.swing.JPanel; 10 11 /** 12 * A sample modal dialog that displays a message and waits for the user to click the OK button. 13 */ 14 public class AboutDialog extends JDialog 15 { 16 public AboutDialog(JFrame owner) 17 { 18 super(owner, "About DialogTest", true); 19 20 // add HTML label to center 21 22 add( 23 new JLabel( 24 "<html><h1><i>Core Java</i></h1><hr>By Cay Horstmann</html>"), 25 BorderLayout.CENTER); 26 27 // OK button closes the dialog 28 29 JButton ok = new JButton("OK"); 30 ok.addActionListener(event -> setVisible(false)); 31 32 // add OK button to southern border 33 34 JPanel panel = new JPanel(); 35 panel.add(ok); 36 add(panel, BorderLayout.SOUTH); 37 38 pack(); 39 } 40 }
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。
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1 package dataExchange; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class DataExchangeTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new DataExchangeFrame(); 16 frame.setTitle("DataExchangeTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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1 package dataExchange; 2 3 import java.awt.BorderLayout; 4 import java.awt.Component; 5 import java.awt.Frame; 6 import java.awt.GridLayout; 7 8 import javax.swing.JButton; 9 import javax.swing.JDialog; 10 import javax.swing.JLabel; 11 import javax.swing.JPanel; 12 import javax.swing.JPasswordField; 13 import javax.swing.JTextField; 14 import javax.swing.SwingUtilities; 15 16 /** 17 * A password chooser that is shown inside a dialog 18 */ 19 public class PasswordChooser extends JPanel 20 { 21 private JTextField username; 22 private JPasswordField password; 23 private JButton okButton; 24 private boolean ok; 25 private JDialog dialog; 26 27 public PasswordChooser() 28 { 29 setLayout(new BorderLayout()); 30 31 // construct a panel with user name and password fields 32 33 JPanel panel = new JPanel(); 34 panel.setLayout(new GridLayout(2, 2)); 35 panel.add(new JLabel("User name:")); 36 panel.add(username = new JTextField("")); 37 panel.add(new JLabel("Password:")); 38 panel.add(password = new JPasswordField("")); 39 add(panel, BorderLayout.CENTER); 40 41 // create Ok and Cancel buttons that terminate the dialog 42 43 okButton = new JButton("Ok"); 44 okButton.addActionListener(event -> { 45 ok = true; 46 dialog.setVisible(false); 47 }); 48 49 JButton cancelButton = new JButton("Cancel"); 50 cancelButton.addActionListener(event -> dialog.setVisible(false)); 51 52 // add buttons to southern border 53 54 JPanel buttonPanel = new JPanel(); 55 buttonPanel.add(okButton); 56 buttonPanel.add(cancelButton); 57 add(buttonPanel, BorderLayout.SOUTH); 58 } 59 60 /** 61 * Sets the dialog defaults. 62 * @param u the default user information 63 */ 64 public void setUser(User u) 65 { 66 username.setText(u.getName()); 67 } 68 69 /** 70 * Gets the dialog entries. 71 * @return a User object whose state represents the dialog entries 72 */ 73 public User getUser() 74 { 75 return new User(username.getText(), password.getPassword()); 76 } 77 78 /** 79 * Show the chooser panel in a dialog 80 * @param parent a component in the owner frame or null 81 * @param title the dialog window title 82 */ 83 public boolean showDialog(Component parent, String title) 84 { 85 ok = false; 86 87 // locate the owner frame 88 89 Frame owner = null; 90 if (parent instanceof Frame) 91 owner = (Frame) parent; 92 else 93 owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent); 94 95 // if first time, or if owner has changed, make new dialog 96 97 if (dialog == null || dialog.getOwner() != owner) 98 { 99 dialog = new JDialog(owner, true); 100 dialog.add(this); 101 dialog.getRootPane().setDefaultButton(okButton); 102 dialog.pack(); 103 } 104 105 // set title and show dialog 106 107 dialog.setTitle(title); 108 dialog.setVisible(true); 109 return ok; 110 } 111 }
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1 package dataExchange; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * A frame with a menu whose File->Connect action shows a password dialog. 9 */ 10 public class DataExchangeFrame extends JFrame 11 { 12 public static final int TEXT_ROWS = 20; 13 public static final int TEXT_COLUMNS = 40; 14 private PasswordChooser dialog = null; 15 private JTextArea textArea; 16 17 public DataExchangeFrame() 18 { 19 // construct a File menu 20 21 JMenuBar mbar = new JMenuBar(); 22 setJMenuBar(mbar); 23 JMenu fileMenu = new JMenu("File"); 24 mbar.add(fileMenu); 25 26 // add Connect and Exit menu items 27 28 JMenuItem connectItem = new JMenuItem("Connect"); 29 connectItem.addActionListener(new ConnectAction()); 30 fileMenu.add(connectItem); 31 32 // The Exit item exits the program 33 34 JMenuItem exitItem = new JMenuItem("Exit"); 35 exitItem.addActionListener(event -> System.exit(0)); 36 fileMenu.add(exitItem); 37 38 textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS); 39 add(new JScrollPane(textArea), BorderLayout.CENTER); 40 pack(); 41 } 42 43 /** 44 * The Connect action pops up the password dialog. 45 */ 46 private class ConnectAction implements ActionListener 47 { 48 public void actionPerformed(ActionEvent event) 49 { 50 // if first time, construct dialog 51 52 if (dialog == null) dialog = new PasswordChooser(); 53 54 // set default values 55 dialog.setUser(new User("yourname", null)); 56 57 // pop up dialog 58 if (dialog.showDialog(DataExchangeFrame.this, "Connect")) 59 { 60 // if accepted, retrieve user input 61 User u = dialog.getUser(); 62 textArea.append("user name = " + u.getName() + ", password = " 63 + (new String(u.getPassword())) + "\n"); 64 } 65 } 66 } 67 }
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1 package dataExchange; 2 3 /** 4 * A user has a name and password. For security reasons, the password is stored as a char[], not a 5 * String. 6 */ 7 public class User 8 { 9 private String name; 10 private char[] password; 11 12 public User(String aName, char[] aPassword) 13 { 14 name = aName; 15 password = aPassword; 16 } 17 18 public String getName() 19 { 20 return name; 21 } 22 23 public char[] getPassword() 24 { 25 return password; 26 } 27 28 public void setName(String aName) 29 { 30 name = aName; 31 } 32 33 public void setPassword(char[] aPassword) 34 { 35 password = aPassword; 36 } 37 }
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。
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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); }); } }
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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; } }
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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); } }); } }
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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"))); } }
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。
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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); }); } }
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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); } } }
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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); } }
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。
实验总结:
本次实验主要学习了如何设计简单的UI交互界面,内容比较多,还需要继续在实践中掌握这些用法,实验10~16比较难理解,还需多多交流学习。