简单文本编辑器

一、前言

　　聚天地之灵气，集日月之精华！一个简单的java文本编辑器由此而生。毕设所需，很是无奈！

二、界面预览

    

三、实现思路

　　1.字体选择器的实现

　　(1).字体类

class MyFont{
    private Font font;
    private Color color;

    public Font getFont() {
        return font;
    }

    public void setFont(Font font) {
        this.font = font;
    }

    public Color getColor() {
        return color;
    }

    public void setColor(Color color) {
        this.color = color;
    }
    //字体名称索引
    private int familyIndex = -1;
    //字体大小索引
    private int sizeIndex = -1;
    //字体颜色索引
    private int colorIndex = -1;
    //字体风格索引
    private int styleIndex = -1;

    public int getFamilyIndex() {
        return familyIndex;
    }

    public int getSizeIndex() {
        return sizeIndex;
    }

    public int getColorIndex() {
        return colorIndex;
    }

    public int getStyleIndex() {
        return styleIndex;
    }

    public void setFamilyIndex(int familyIndex) {
        this.familyIndex = familyIndex;
    }

    public void setSizeIndex(int sizeIndex) {
        this.sizeIndex = sizeIndex;
    }

    public void setColorIndex(int colorIndex) {
        this.colorIndex = colorIndex;
    }

    public void setStyleIndex(int styleIndex) {
        this.styleIndex = styleIndex;
    }

    @Override
    public String toString() {
        return familyIndex + " " + sizeIndex + " " + styleIndex + " " + colorIndex + " \n" +
                font + " " + color; 
    }
    
}

　　(2).字体选择器

public class JFontChooser extends JPanel {

    //定义变量
    private String current_fontName = "宋体";//当前的字体名称,默认宋体.
    private int current_fontStyle = Font.PLAIN;//当前的字样,默认常规.
    private int current_fontSize = 9;//当前字体大小,默认9号.
    private Color current_color = Color.BLACK;//当前字色,默认黑色.
    private Component parent;//弹出dialog的父窗体.
    private JDialog dialog;//用于显示模态的窗体
    private MyFont myfont;//带有Color的字体.
    private JLabel lblFont;//选择字体的LBL
    private JLabel lblStyle;//选择字型的LBL
    private JLabel lblSize;//选择字大小的LBL
    private JLabel lblColor;//选择Color的label
    private JTextField txtFont;//显示选择字体的TEXT
    private JTextField txtStyle;//显示选择字型的TEXT
    private JTextField txtSize;//显示选择字大小的TEXT
    private JList lstFont;//选择字体的列表.
    private JList lstStyle;//选择字型的列表.
    private JList lstSize;//选择字体大小的列表.
    private JComboBox cbColor;//选择Color的下拉框.
    private JButton ok, cancel;//"确定","取消"按钮.
    private JScrollPane spFont;
    private JScrollPane spSize;
    private JLabel lblShow;//显示效果的label.
    private JPanel showPan;//显示框.
    private Map sizeMap;//字号映射表.
    private Map colorMap;//字着色映射表.
    
    //定义变量_结束________________
    public JFontChooser(MyFont curFont) {
        //实例化变量
        lblFont = new JLabel("字体:");
        lblStyle = new JLabel("字型:");
        lblSize = new JLabel("大小:");
        lblColor = new JLabel("颜色:");
        lblShow = new JLabel("Sample Test!", JLabel.CENTER);
        txtFont = new JTextField("宋体");
        txtStyle = new JTextField("常规");
        txtSize = new JTextField("9");
        //取得当前环境可用字体.
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        String[] fontNames = ge.getAvailableFontFamilyNames();
        lstFont = new JList(fontNames);
        //字形.
        lstStyle = new JList(new String[]{"常规", "斜休", "粗休", "粗斜休"});
        //字号.
        String[] sizeStr = new String[]{
            "8", "9", "10", "11", "12", "14", "16", "18", "20", "22", "24", "26", "28", "36", "48", "72",
            "初号", "小初", "一号", "小一", "二号", "小二", "三号", "小三", "四号", "小四", "五号", "小五", "六号", "小六", "七号", "八号"
        };
        int sizeVal[] = {8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 36, 48, 72, 42, 36, 26, 24, 22, 18, 16, 15, 14, 12, 11, 9, 8, 7, 6, 5};
        sizeMap = new HashMap();
        for (int i = 0; i < sizeStr.length; ++i) {
            sizeMap.put(sizeStr[i], sizeVal[i]);
        }
        lstSize = new JList(sizeStr);
        spFont = new JScrollPane(lstFont);
        spSize = new JScrollPane(lstSize);
        
        String[] colorStr = new String[]{
                "黑色", "蓝色", "深灰", "灰色", "绿色", "浅灰", "洋红", "桔黄", "粉红", "红色", "白色", "黄色"
        };
        Color[] colorVal = new Color[]{
                Color.BLACK, Color.BLUE, Color.DARK_GRAY, Color.GRAY, Color.GREEN, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE, Color.PINK, Color.RED, Color.WHITE, Color.YELLOW
        };
        colorMap = new HashMap();
        for (int i = 0; i < colorStr.length; i++) {
            colorMap.put(colorStr[i], colorVal[i]);
        }
        cbColor = new JComboBox(colorStr);
        showPan = new JPanel();
        ok = new JButton("确定");
        cancel = new JButton("取消");
        //实例化变量_结束
        
        //布局控件
        this.setLayout(null);//不用布局管理器.     
        add(lblFont);
        lblFont.setBounds(12, 10, 30, 20);
        txtFont.setEditable(false);
        add(txtFont);
        txtFont.setBounds(10, 30, 155, 20);
        add(spFont);
        spFont.setBounds(10, 50, 155, 100);
        
        add(lblStyle);
        lblStyle.setBounds(175, 10, 30, 20);
        txtStyle.setEditable(false);
        add(txtStyle);
        txtStyle.setBounds(175, 30, 130, 20);
        lstStyle.setBorder(javax.swing.BorderFactory.createLineBorder(Color.gray));
        add(lstStyle);
        lstStyle.setBounds(175, 50, 130, 100);
        
        add(lblSize);
        lblSize.setBounds(320, 10, 30, 20);
        txtSize.setEditable(false);
        add(txtSize);
        txtSize.setBounds(320, 30, 60, 20);
        add(spSize);
        spSize.setBounds(320, 50, 60, 100);
        
        
        add(lblColor);
        lblColor.setBounds(13, 170, 30, 20);
        add(cbColor);
        cbColor.setBounds(10, 195, 130, 22);
        cbColor.setMaximumRowCount(5);
        
        showPan.setBorder(javax.swing.BorderFactory.createTitledBorder("示例"));
        add(showPan);
        showPan.setBounds(150, 170, 230, 100);
        showPan.setLayout(new BorderLayout());
        lblShow.setBackground(Color.white);
        showPan.add(lblShow);
        add(ok);
        ok.setBounds(10, 240, 60, 20);
        add(cancel);
        cancel.setBounds(80, 240, 60, 20);
        //布局控件_结束
        
        //事件
        lstFont.addListSelectionListener(new ListSelectionListener() {
            
            public void valueChanged(ListSelectionEvent e) {
                current_fontName = (String) lstFont.getSelectedValue();
                txtFont.setText(current_fontName);
                lblShow.setFont(new Font(current_fontName, current_fontStyle, current_fontSize));
            }
        });
        
        lstStyle.addListSelectionListener(new ListSelectionListener() {
            
            public void valueChanged(ListSelectionEvent e) {
                String value = (String) ((JList) e.getSource()).getSelectedValue();
                if (value.equals("常规")) {
                    current_fontStyle = Font.PLAIN;
                }
                if (value.equals("斜休")) {
                    current_fontStyle = Font.ITALIC;
                }
                if (value.equals("粗休")) {
                    current_fontStyle = Font.BOLD;
                }
                if (value.equals("粗斜休")) {
                    current_fontStyle = Font.BOLD | Font.ITALIC;
                }
                txtStyle.setText(value);
                lblShow.setFont(new Font(current_fontName, current_fontStyle, current_fontSize));
            }
        });
        
        lstSize.addListSelectionListener(new ListSelectionListener() {
            
            public void valueChanged(ListSelectionEvent e) {
                current_fontSize = (Integer) sizeMap.get(lstSize.getSelectedValue());
                txtSize.setText(String.valueOf(current_fontSize));
                lblShow.setFont(new Font(current_fontName, current_fontStyle, current_fontSize));
            }
        });
        
        cbColor.addActionListener(new ActionListener() {
            
            public void actionPerformed(ActionEvent e) {
                current_color = (Color) colorMap.get(cbColor.getSelectedItem());
                lblShow.setForeground(current_color);
            }
        });
        
        ok.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                myfont = new MyFont();
                myfont.setFont(new Font(current_fontName, current_fontStyle, current_fontSize));
                myfont.setColor(current_color);
                myfont.setColorIndex(cbColor.getSelectedIndex());
                myfont.setFamilyIndex(lstFont.getSelectedIndex());
                myfont.setSizeIndex(lstSize.getSelectedIndex());
                myfont.setStyleIndex(lstStyle.getSelectedIndex());
                dialog.dispose();
                dialog = null;
            }
        });
        
        cancel.addActionListener(new ActionListener() {
            
            public void actionPerformed(ActionEvent e) {
                myfont = null;
                dialog.dispose();
                dialog = null;
            }
        });
        //事件_结束
        
        if(curFont != null){
            if(curFont.getFamilyIndex() != -1) {
                lstFont.setSelectedIndex(curFont.getFamilyIndex());
                lstFont.ensureIndexIsVisible(curFont.getFamilyIndex());
            } else {
                lstFont.setSelectedValue("宋体", true);
            }
            
            lstSize.setSelectedIndex(curFont.getSizeIndex());
            lstSize.ensureIndexIsVisible(curFont.getSizeIndex());
            
            lstStyle.setSelectedIndex(curFont.getStyleIndex());
            lstStyle.ensureIndexIsVisible(curFont.getStyleIndex());
            cbColor.setSelectedIndex(curFont.getColorIndex());
        }
    }

    public MyFont showDialog(Frame parent, String title, int dx, int dy) {
        if(title == null)
            title = "Font";
        dialog = new JDialog(parent, title,true);
        dialog.add(this);
        dialog.setResizable(false);
        dialog.setBounds(dx, dy, 400, 310);
        dialog.addWindowListener(new WindowAdapter() {

            @Override
            public void windowClosing(WindowEvent e) {
                myfont = null;
                dialog.removeAll();
                dialog.dispose();
                dialog = null;
            }
        });

        dialog.setVisible(true);
        return myfont;
    }
}  

　　2.编辑器的实现

　　(1).字符串样式修饰类

　　　　功能：主要是将JTextPane对应的Document的文本进行处理。使得不同类型的文本显示为不同的风格样式。由于这个编辑器是用来编辑java语言的，所以会对java中的关键字进行特殊的显示，使得关键字，注释，以及其他串的不同的显示。

class DecorateKeyWords{
    //java中的关键字
    private static final String KEYWORDS[]={"abstract","assert","boolen","break","byte","case","catch","char","class","const",  
         "continue","default","do","double","else","enum","extends","final","finally","float","for",  
         "if","implements","import","instanceof","int","interface","long","native","new","package",  
         "private","protected","public","return","short","static","strictfp","super","switch","synchrpnized",  
         "this","throw","throws","transient","try","void","volatile","while"
    };  
     // 准备关键字     
    private static HashSet<String> keywords = new HashSet<String>(); 
    
    public static void decorateStyleConstants(SimpleAttributeSet attr, Font font){
        StyleConstants.setFontFamily(attr, font.getFamily());
        StyleConstants.setFontSize(attr, font.getSize());
        switch(font.getStyle()) {
            case Font.BOLD :
                StyleConstants.setBold(attr, true);
                break;
            case Font.ITALIC :
                StyleConstants.setItalic(attr, true);
                break;
            case Font.PLAIN :
                StyleConstants.setItalic(attr, false);
                StyleConstants.setBold(attr, false);
                break;
            case Font.BOLD | Font.ITALIC :
                StyleConstants.setItalic(attr, true);
                StyleConstants.setBold(attr, true);
                break;
            default :
                break;
        }
    }
    
    public static void decorateKeyWords(JTextPane tp, MyFont myFont) {  
      //初始化关键字
      for(int i = 0; i<KEYWORDS.length; i++)  
         keywords.add(KEYWORDS[i]);
      // 对所有关键词进行修饰颜色  
      String text = tp.getText().replaceAll("\\r", "");  
      StyledDocument doc = tp.getStyledDocument();  
      SimpleAttributeSet keyWordAttr = new SimpleAttributeSet();  
      StyleConstants.setForeground(keyWordAttr, Color.cyan);
      decorateStyleConstants(keyWordAttr, myFont.getFont());
      SimpleAttributeSet otherWordAttr = new SimpleAttributeSet();  
      StyleConstants.setForeground(otherWordAttr, myFont.getColor());
      decorateStyleConstants(otherWordAttr, myFont.getFont());
      ListIterator<WordNode> iterator1 = split(text, "\\s|\\{|\\}|\\(|\\)|\\<|\\>|\\.|\\n");  
      while (iterator1.hasNext()) {  
          WordNode wn = iterator1.next(); 
          if (keywords.contains(wn.getWord())) { 
              doc.setCharacterAttributes(wn.getLocation(), wn.getWord().length(), keyWordAttr, true);  
          } else {
              doc.setCharacterAttributes(wn.getLocation(), wn.getWord().length(), otherWordAttr, true);
          }
      }  
      // 对注释行进行修饰不同的颜色  
      SimpleAttributeSet annotationAttr = new SimpleAttributeSet();  
      StyleConstants.setForeground(annotationAttr, Color.green); 
      decorateStyleConstants(annotationAttr, myFont.getFont());
      ListIterator<WordNode> iterator2 = split(text, "\\n");  
      boolean exegesis = false; // 是否加了/*的注释  
      while (iterator2.hasNext()) {  
          WordNode wn = iterator2.next();  
          if (wn.getWord().startsWith("//")) {  
              doc.setCharacterAttributes(wn.getLocation(), wn.getWord()  
                      .length(), annotationAttr, true);  
          } else if (wn.getWord().startsWith("/*")  && wn.getWord().endsWith("*/")) {  
              doc.setCharacterAttributes(wn.getLocation(), wn.getWord()  
                      .length(), annotationAttr, true);  
          } else if (wn.getWord().startsWith("/*")  && !wn.getWord().endsWith("*/")) {  
              exegesis = true;  
              doc.setCharacterAttributes(wn.getLocation(), wn.getWord()  
                      .length(), annotationAttr, true);  
          } else if (!wn.getWord().startsWith("/*") && wn.getWord().endsWith("*/") && true == exegesis) {  
              doc.setCharacterAttributes(wn.getLocation(), wn.getWord()  
                      .length(), annotationAttr, true);  
              exegesis = false;  
          } else if (true == exegesis) {  
              doc.setCharacterAttributes(wn.getLocation(), wn.getWord()  
                      .length(), annotationAttr, true);  
          }  
          }  
     }  
     
     /**  
       * 按照指定的多个字符进行字符串分割，如‘ ’或‘,’等  
      * @param str   
      *            被分割的字符串  
      * @param regexs  
      *            要分割所需的符号  
      * @return 包含WordNodeList对象的iterator  
      */  
     private static ListIterator<WordNode> split(String str,String regex) {  
         Pattern p = Pattern.compile(regex);  
         Matcher m = p.matcher(str); 
         List<WordNode> nodeList = new ArrayList();  
         int strStart = 0; // 分割单词的首位置  
         String s; // 分割的单词  
         WordNode wn; // StringNode节点  
         while (m.find()) {  
             s = str.substring(strStart, m.start());  
             if (!s.equals(new String())) {  
                 wn = new WordNode(strStart, s);  
                 nodeList.add(wn);  
             }  
             strStart = m.start() + 1;  
         }  
         s = str.substring(strStart, str.length());  
         wn = new WordNode(strStart, s);  
         nodeList.add(wn);  
         return nodeList.listIterator();  
     }  
}

　　(2).串节点

　　　　功能：通过正则表达式，将JTextPane对应的Document的文本进行分割，记录每个分割串的起始位置，然后通过字符串修饰类(DecorateKeyWords)中的decorateStyleConstants方法根据每个分割串的起始位置对JTextPane对应的Document的文本进行不同风格样式的修饰。

class WordNode {  
     private int location;  
     private String word;  
     public WordNode(int location, String str) {  
         super();  
         this.location = location;  
         this.word = str;  
     }  
     public int getLocation() {  
         return location;  
     }  
     public String getWord() {  
         return word;  
     }  
}  

　　(3).编辑器类

　　　　功能：文件的新建，文件的保存，文件的编辑；确定JTextPane中光标的位置（行号和列号），显示行号，字体样式的选择，重新设置新字体样式。

　　　　通过DocumentListener可以监听文档的改变，删除和插入的时候，调用字体选择器对文档的内容重新设置样式，另外在文档删除的时候判断是否行数减少，如果是，则更新行号面板的显示。

textPane.getDocument().addDocumentListener(new DocumentListener() {
    @Override
    public void changedUpdate(DocumentEvent e) {}
    @Override
    public void insertUpdate(final DocumentEvent e) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                DecorateKeyWords.decorateKeyWords(textPane, myFont);
            }
        }).start();
    }
    @Override
    public void removeUpdate(DocumentEvent e) {
        new Thread(new Runnable() {  
            @Override
            public void run() {
                String text;
                try {
                    text = textPane.getDocument().getText(0, textPane.getDocument().getLength()).replaceAll("\\r", "");
                    Pattern pattern = Pattern.compile("\\n");
                    Matcher matcher = pattern.matcher(text);
                    int lineRow = 1;
                    while(matcher.find()){
                        //计算行数
                        ++lineRow;
                    }
                    while(lineRow < linePane.getComponentCount()) {
                        --lineNum;
                        linePane.remove(linePane.getComponentCount()-1);
                    }
                    linePane.updateUI();
                    
                } catch (BadLocationException ex) {
                    ex.printStackTrace();
                } finally {
                    DecorateKeyWords.decorateKeyWords(textPane, myFont);
                }
            }
        }).start();
    }
}

　　通过CaretListener可以监听光标位置的变化，实时获得光标所在的行号和列号并显示出来。

textPane.addCaretListener(new CaretListener() {
    @Override
    public void caretUpdate(CaretEvent e) {
         try {
            String text = textPane.getDocument().getText(0, e.getDot()).replaceAll("\\r", "");
            Pattern pattern = Pattern.compile("\\n");
            Matcher matcher = pattern.matcher(text);
            int lineRow = 1;
            int lastLineBeginPos = -1;//记录文本中最后一行的开始的位置 
            while(matcher.find()){
                //计算行数
                ++lineRow;
                lastLineBeginPos = matcher.start();//得到下一行光标所在的位置（根据上一行的换行符）
            }
            int lineCol = e.getDot() - lastLineBeginPos;
            //显示行号和列号
            caretStatusBar.setText("光标 " + lineRow + " : " + lineCol);
         } catch (BadLocationException ey) {
            ey.printStackTrace();
         }
    }
 });

　　通过KeyListener可以监听按键的操作，如果是回车键，那么为行号面板增加新的行号！

textPane.addKeyListener(new KeyAdapter() {
    @Override
    public void keyPressed(KeyEvent e) {
        super.keyPressed(e);
        if(e.getKeyCode() == KeyEvent.VK_ENTER) {
            //添加新的行号
            addLineNum();
        }
    }
 });

 

　　编辑器全部代码如下

public class EditorDemo extends JFrame {
     public static final String MAX_LINE_NUM = "9999";
     private JTextPane textPane = new JTextPane(); //文本窗格，编辑窗口
     private JLabel timeStatusBar = new JLabel(); //时间状态栏
     private JLabel caretStatusBar = new JLabel(); //光标位置状态栏
     private JFileChooser filechooser = new JFileChooser(); //文件选择器
     private JPanel linePane = new JPanel(new FlowLayout(FlowLayout.CENTER, 0, 0));
     private int lineNum = 0;
     private  MyFont myFont = null;
     
     private void initTextPaneDocument(){
         textPane.getDocument().addDocumentListener(new DocumentListener() {
            @Override
            public void changedUpdate(DocumentEvent e) {}
            @Override
            public void insertUpdate(final DocumentEvent e) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        DecorateKeyWords.decorateKeyWords(textPane, myFont);
                    }
                }).start();
            }
            @Override
            public void removeUpdate(DocumentEvent e) {
                new Thread(new Runnable() {  
                    @Override
                    public void run() {
                        String text;
                        try {
                            text = textPane.getDocument().getText(0, textPane.getDocument().getLength()).replaceAll("\\r", "");
                            Pattern pattern = Pattern.compile("\\n");
                            Matcher matcher = pattern.matcher(text);
                            int lineRow = 1;
                            while(matcher.find()){
                                //计算行数
                                ++lineRow;
                            }
                            while(lineRow < linePane.getComponentCount()) {
                                --lineNum;
                                linePane.remove(linePane.getComponentCount()-1);
                            }
                            linePane.updateUI();
                            
                        } catch (BadLocationException ex) {
                            ex.printStackTrace();
                        } finally {
                            DecorateKeyWords.decorateKeyWords(textPane, myFont);
                        }
                    }
                }).start();
            }
        });
     }
     
     public EditorDemo() { //构造函数
         super("简单的文本编辑器");  //调用父类构造函数
         
         //初始字体
         myFont = new MyFont();
         myFont.setColor(Color.black);
         myFont.setFont(new Font("宋体", Font.PLAIN, 24));
         myFont.setSizeIndex(19);
         myFont.setStyleIndex(0);
         myFont.setColorIndex(0);
         
         Action[] actions =  //Action数组,各种操作命令
         {
            new NewAction(),
            new OpenAction(),
            new SaveAction(),
            new CutAction(),
            new CopyAction(),
            new PasteAction(),
            new NewFontStyle(),
            new AboutAction(),
            new ExitAction()
          };
         textPane.addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                super.keyPressed(e);
                if(e.getKeyCode() == KeyEvent.VK_ENTER) {
                    //添加新的行号
                    addLineNum();
                }
            }
         });
         
         textPane.addCaretListener(new CaretListener() {
            @Override
            public void caretUpdate(CaretEvent e) {
                 try {
                    String text = textPane.getDocument().getText(0, e.getDot()).replaceAll("\\r", "");
                    Pattern pattern = Pattern.compile("\\n");
                    Matcher matcher = pattern.matcher(text);
                    int lineRow = 1;
                    int lastLineBeginPos = -1;//记录文本中最后一行的开始的位置 
                    while(matcher.find()){
                        //计算行数
                        ++lineRow;
                        lastLineBeginPos = matcher.start();//得到下一行光标所在的位置（根据上一行的换行符）
                    }
                    int lineCol = e.getDot() - lastLineBeginPos;
                    //显示行号和列号
                    caretStatusBar.setText("光标 " + lineRow + " : " + lineCol);
                 } catch (BadLocationException ey) {
                     ey.printStackTrace();
                 }
            }
         });
         initTextPaneDocument();

         setJMenuBar(createJMenuBar(actions));  //设置菜单栏
         add(createJToolBar(actions), BorderLayout.NORTH); //增加工具栏
         JPanel textBackPanel = new JPanel(new BorderLayout());
         textBackPanel.add(linePane, BorderLayout.WEST);//增加行号面板
         textBackPanel.add(textPane, BorderLayout.CENTER);//增加文本面板
         add(new JScrollPane(textBackPanel), BorderLayout.CENTER); //文本窗格嵌入到JscrollPane
         JPanel statusPane = new JPanel(new FlowLayout(FlowLayout.LEFT, 50, 0));
         statusPane.add(caretStatusBar);
         statusPane.add(timeStatusBar);
         //初始化光标位置
         caretStatusBar.setText("光标 1 : 1");
         //初始化系统时间显示
         new Timer().schedule(new TimerTask() {
            @Override
            public void run() {
                Date now = new Date(); 
                SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//可以方便地修改日期格式
                timeStatusBar.setText(dateFormat.format(now)); 
            }
        }, 0, 1000);
         add(statusPane, BorderLayout.SOUTH); //增加状态栏
         
         FontMetrics fm = FontDesignMetrics.getMetrics(myFont.getFont());
         //设置光标的大小
         textPane.setFont(myFont.getFont());
         //设置行数面板的宽度
         linePane.setPreferredSize(new Dimension(fm.stringWidth(MAX_LINE_NUM), 0));
         addLineNum();
        
         setBounds(200, 100, 800, 500); //设置窗口尺寸
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  //关闭窗口时退出程序
         setVisible(true);  //设置窗口可视
     }
     
     private void addLineNum(){
         //为textPane添加行号
         String numText = String.valueOf(++lineNum);
         int tmpNum = MAX_LINE_NUM.length() - (int)(Math.log10(lineNum*1.0)+1);
         String spaces = "";
         while(tmpNum > 0){
             spaces += " ";
             --tmpNum;
         }
         JLabel lineLabel = new JLabel(numText.replaceAll("(\\d+)", spaces+"$1"), JLabel.RIGHT);
         lineLabel.setForeground(Color.GRAY);
         lineLabel.setFont(myFont.getFont());
         linePane.add(lineLabel);
         linePane.updateUI();
     }

     private JMenuBar createJMenuBar(Action[] actions) {  //创建菜单栏
         JMenuBar menubar = new JMenuBar(); //实例化菜单栏
         JMenu menuFile = new JMenu("文件"); //实例化菜单
         JMenu menuEdit = new JMenu("编辑");
         JMenu menuAbout = new JMenu("帮助");
         menuFile.add(new JMenuItem(actions[0])); //增加新菜单项
         menuFile.add(new JMenuItem(actions[1]));
         menuFile.add(new JMenuItem(actions[2]));
         menuFile.add(new JMenuItem(actions[7]));
         menuEdit.add(new JMenuItem(actions[3]));
         menuEdit.add(new JMenuItem(actions[4]));
         menuEdit.add(new JMenuItem(actions[5]));
         menuAbout.add(new JMenuItem(actions[6]));
         menubar.add(menuFile); //增加菜单
         menubar.add(menuEdit);
         menubar.add(menuAbout);
         return menubar; //返回菜单栏
     }

     private JToolBar createJToolBar(Action[] actions) { //创建工具条
         JToolBar toolBar = new JToolBar(); //实例化工具条
         for (int i = 0; i < actions.length; i++) {
             JButton bt = new JButton(actions[i]); //实例化新的按钮
             bt.setRequestFocusEnabled(false); //设置不需要焦点
             toolBar.add(bt); //增加按钮到工具栏
         }
         return toolBar;  //返回工具栏
     }
     
     class NewFontStyle extends AbstractAction{
        public NewFontStyle() {
             super("字体");
        }
        @Override
        public void actionPerformed(ActionEvent e) {
            JFontChooser one = new JFontChooser(myFont);
            MyFont tmpFont = one.showDialog(null, "字体选择器", textPane.getLocationOnScreen().x, textPane.getLocationOnScreen().y); 
            if(tmpFont == null) return;
            myFont = tmpFont;
            //重新设置 textPane的字体，改变光标的大小
            textPane.setFont(myFont.getFont());
            FontMetrics fm = FontDesignMetrics.getMetrics(myFont.getFont());
            //重新设置数字行数面板的宽度
            linePane.setPreferredSize(new Dimension(fm.stringWidth(MAX_LINE_NUM), 0));
            //重新设置行号的字体
            for(int i=0; i < linePane.getComponentCount(); ++i)
                linePane.getComponent(i).setFont(myFont.getFont());
            
            StyledDocument doc = textPane.getStyledDocument();  
              SimpleAttributeSet wordAttr = new SimpleAttributeSet(); 
              DecorateKeyWords.decorateStyleConstants(wordAttr, myFont.getFont());
              doc.setCharacterAttributes(0, doc.getLength(), wordAttr, false);
        }
     }

     class NewAction extends AbstractAction { //新建文件命令
         public NewAction() {
             super("新建");
         }
         public void actionPerformed(ActionEvent e) {
             textPane.setDocument(new DefaultStyledDocument()); //清空文档
             while(linePane.getComponentCount() > 1)
                 linePane.remove(linePane.getComponent(linePane.getComponentCount()-1));
             linePane.updateUI();
             lineNum = 1;
             initTextPaneDocument();
         }
     }

     class OpenAction extends AbstractAction { //打开文件命令
          public OpenAction() {
              super("打开");
          }
          public void actionPerformed(ActionEvent e) {
              int i = filechooser.showOpenDialog(EditorDemo.this); //显示打开文件对话框
              if (i == JFileChooser.APPROVE_OPTION) { //点击对话框中打开选项
                  File f = filechooser.getSelectedFile(); //得到选择的文件
                  try {
                      InputStream is = new FileInputStream(f); //得到文件输入流
                      textPane.read(is, "d"); //读入文件到文本窗格
                      is.close();
                      is = new FileInputStream(f);
                      LineNumberReader lnr = new LineNumberReader(new InputStreamReader(is));
                      lnr.skip(Long.MAX_VALUE);
                      int newLineNum = lnr.getLineNumber()+1;
                      lnr.close();
                      if(lineNum < newLineNum){
                          while(lineNum < newLineNum)
                              addLineNum();
                      } else {
                          while(lineNum > newLineNum && lineNum > 1){
                              linePane.remove(linePane.getComponentCount()-1);
                              --lineNum;
                          }
                          linePane.updateUI();
                      }
                      
                  } catch (Exception ex) {
                      ex.printStackTrace();  //输出出错信息
                  }
              }
              DecorateKeyWords.decorateKeyWords(textPane, myFont);
              initTextPaneDocument();
          }
     }

     class SaveAction extends AbstractAction {  //保存命令
         public SaveAction() {
             super("保存");
         }
         public void actionPerformed(ActionEvent e) {
             int i = filechooser.showSaveDialog(EditorDemo.this); //显示保存文件对话框
             if (i == JFileChooser.APPROVE_OPTION) {  //点击对话框中保存按钮
                 File f = filechooser.getSelectedFile(); //得到选择的文件
                 try {
                     FileOutputStream out = new FileOutputStream(f);  //得到文件输出流
                     out.write(textPane.getText().getBytes()); //写出文件    
                 } catch (Exception ex) {
                     ex.printStackTrace(); //输出出错信息
                 }
             }
         }
     }

     class ExitAction extends AbstractAction { //退出命令
          public ExitAction() {
              super("退出");
          }
          public void actionPerformed(ActionEvent e) {
              System.exit(0);  //退出程序
          }
     }

     class CutAction extends AbstractAction {  //剪切命令
          public CutAction() {
              super("剪切");
          }
          public void actionPerformed(ActionEvent e) {
              textPane.cut();  //调用文本窗格的剪切命令
          }
     }

     class CopyAction extends AbstractAction {  //拷贝命令
         public CopyAction() {
             super("拷贝");
         }
         public void actionPerformed(ActionEvent e) {
             textPane.copy();  //调用文本窗格的拷贝命令
         }
     }

     class PasteAction extends AbstractAction {  //粘贴命令
         public PasteAction() {
             super("粘贴");
         }
         public void actionPerformed(ActionEvent e) {
             textPane.paste();  //调用文本窗格的粘贴命令
         }
     }

     class AboutAction extends AbstractAction { //关于选项命令
         public AboutAction() {
             super("关于");
         }
         public void actionPerformed(ActionEvent e) {
             JOptionPane.showMessageDialog(EditorDemo.this, "简单的文本编辑器演示"); //显示软件信息
         }
     }

     public static void main(String[] args) {
         new EditorDemo();
     }
}