mynotepad.java

Java记事本,类似于Windows附带的记事本

        JLabel replaceContentLabel = new JLabel("替换为(P)　 :");
        final JTextField findText = new JTextField(30);
        final JTextField replaceText = new JTextField(30);
        final JCheckBox matchcase = new JCheckBox("区分大小写(C)");

        ButtonGroup bGroup = new ButtonGroup();
        final JRadioButton up = new JRadioButton("向上(U)");
        final JRadioButton down = new JRadioButton("向下(D)");
        down.setSelected(true);
        bGroup.add(up);
        bGroup.add(down);
        JButton searchNext = new JButton("查找下一个(F)");
        JButton replace = new JButton("替换(R)");
        final JButton replaceAll = new JButton("全部替换(A)");
        //"替换"按钮的事件处理
        replace.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                if (replaceText.getText().length() == 0 && tex.getSelectedText() != null) {
                    tex.replaceSelection("");
                }
                if (replaceText.getText().length() > 0 && tex.getSelectedText() != null) {
                    tex.replaceSelection(replaceText.getText());
                }
            }
        });
        //"替换全部"按钮的事件处理
        replaceAll.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                tex.setCaretPosition(0); //将光标放到编辑区开头
                int a = 0, b = 0, replaceCount = 0;
                if (findText.getText().length() == 0) {
                    JOptionPane.showMessageDialog(findDialog, "请填写查找内容!", "提示",
                            JOptionPane.WARNING_MESSAGE);
                    findText.requestFocus(true);
                    return;
                }
                while (a > -1) {
                    int FindStartPos = tex.getCaretPosition();
                    String str1, str2, str3, str4, strA, strB;
                    str1 = tex.getText();
                    str2 = str1.toLowerCase();
                    str3 = findText.getText();
                    str4 = str3.toLowerCase();

                    if (matchcase.isSelected()) {
                        strA = str1;
                        strB = str3;
                    } else {
                        strA = str2;
                        strB = str4;
                    }
                    if (up.isSelected()) {
                        if (tex.getSelectedText() == null) {
                            a = strA.lastIndexOf(strB, FindStartPos - 1);
                        } else {
                            a = strA.lastIndexOf(strB, FindStartPos - findText.getText().length() - 1);
                        }
                    } else if (down.isSelected()) {
                        if (tex.getSelectedText() == null) {
                            a = strA.indexOf(strB, FindStartPos);
                        } else {
                            a = strA.indexOf(strB, FindStartPos - findText.getText().length() + 1);
                        }
                    }

                    if (a > -1) {
                        if (up.isSelected()) {
                            tex.setCaretPosition(a);
                            b = findText.getText().length();
                            tex.select(a, a + b);
                        } else if (down.isSelected()) {
                            tex.setCaretPosition(a);
                            b = findText.getText().length();
                            tex.select(a, a + b);
                        }
                    } else {
                        if (replaceCount == 0) {
                            JOptionPane.showMessageDialog(findDialog,
                                    "找不到您查找的内容!", "记事本",
                                    JOptionPane.INFORMATION_MESSAGE);
                        } else {
                            JOptionPane.showMessageDialog(findDialog, "成功替换" + replaceCount + "个匹配内容!", "替换成功",
                                    JOptionPane.INFORMATION_MESSAGE);
                        }
                    }
                    if (replaceText.getText().length() == 0 && tex.getSelectedText() != null) {
                        tex.replaceSelection("");
                        replaceCount++;
                    }

                    if (replaceText.getText().length() > 0 && tex.getSelectedText() != null) {
                        tex.replaceSelection(replaceText.getText());
                        replaceCount++;
                    }
                }//end while
            }
        }); //"替换全部"按钮的事件处理结束

        //"查找下一个"按钮事件处理
        searchNext.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                int a = 0, b = 0;
                int FindStartPos = tex.getCaretPosition();
                String str1, str2, str3, str4, strA, strB;
                str1 = tex.getText();
                str2 = str1.toLowerCase();
                str3 = findText.getText();
                str4 = str3.toLowerCase();

                //"区分大小写"的CheckBox被选中
                if (matchcase.isSelected()) {
                    strA = str1;
                    strB = str3;
                } else {
                    strA = str2;
                    strB = str4;
                }
                if (up.isSelected()) {
                    if (tex.getSelectedText() == null) {
                        a = strA.lastIndexOf(strB, FindStartPos - 1);
                    } else {
                        a = strA.lastIndexOf(strB, FindStartPos - findText.getText().length() - 1);
                    }
                } else if (down.isSelected()) {
                    if (tex.getSelectedText() == null) {
                        a = strA.indexOf(strB, FindStartPos);
                    } else {
                        a = strA.indexOf(strB, FindStartPos - findText.getText().length() + 1);
                    }
                }
                if (a > -1) {
                    if (up.isSelected()) {
                        tex.setCaretPosition(a);
                        b = findText.getText().length();
                        tex.select(a, a + b);
                    } else if (down.isSelected()) {
                        tex.setCaretPosition(a);
                        b = findText.getText().length();
                        tex.select(a, a + b);
                    }
                } else {
                    JOptionPane.showMessageDialog(null, "找不到您查找的内容!", "记事本",
                            JOptionPane.INFORMATION_MESSAGE);
                }
            }
        });//"查找下一个"按钮事件处理结束

        //"取消"按钮及事件处理
        JButton cancel = new JButton("取消");
        cancel.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                findDialog.dispose();
            }
        });
        //创建"查找与替换"对话框的界面
        JPanel bottomPanel = new JPanel();
        JPanel centerPanel = new JPanel();
        JPanel topPanel = new JPanel();
        JPanel direction = new JPanel();

        direction.setBorder(BorderFactory.createTitledBorder("方向"));
        direction.add(up);
        direction.add(down);

        JPanel replacePanel = new JPanel();
        replacePanel.setLayout(new GridLayout(1, 2));
        replacePanel.add(replace);
        replacePanel.add(replaceAll);

        topPanel.add(searchContentLabel);
        topPanel.add(findText);
        topPanel.add(searchNext);

        centerPanel.add(replaceContentLabel);
        centerPanel.add(replaceText);
        centerPanel.add(replacePanel);

        bottomPanel.add(matchcase);
        bottomPanel.add(direction);
        bottomPanel.add(cancel);

        con.add(topPanel);
        con.add(centerPanel);
        con.add(bottomPanel);
        con.add(replacePanel);
        //设置"查找与替换"对话框的大小、可更改大小(否)、位置和可见性
        findDialog.setSize(550, 240);
        findDialog.setResizable(true);
        findDialog.setLocation(230, 280);
        findDialog.setVisible(true);
    }//方法mySearch()结束
//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

//$$$$$$$$$$$$$$$$$$$$设置菜单项的可用性:剪切,复制,粘贴,删除功能$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
    public void checkMenuItemEnabled() {
        //主要是通过判断编辑区是否有文本被选中来设置这些操作(剪切,复制,删除)的可用性;
        //通过判断剪贴板信息设置粘贴选项的可用性
        String selectText = tex.getSelectedText();
        if (selectText == null) {
            me2.setEnabled(false); //剪切
            popupMenu_Cut.setEnabled(false);
            bt_cut.setEnabled(false);
            me3.setEnabled(false); //复制
            popupMenu_Copy.setEnabled(false);
            bt_copy.setEnabled(false);
            me5.setEnabled(false); //删除
            popupMenu_Delete.setEnabled(false);

        } else {
            me2.setEnabled(true); //剪切
            popupMenu_Cut.setEnabled(true);
            bt_cut.setEnabled(true);
            me3.setEnabled(true); //复制
            popupMenu_Copy.setEnabled(true);
            bt_copy.setEnabled(true);
            me5.setEnabled(true); //删除
            popupMenu_Delete.setEnabled(true);

        }
        //通过判断系统剪贴板判定粘贴功能可用性判断
        Transferable contents = clipBoard.getContents(this);
        if (contents == null) {
            me4.setEnabled(false);
            popupMenu_Paste.setEnabled(false);
            bt_paste.setEnabled(false);
        } else {
            me4.setEnabled(true);
            popupMenu_Paste.setEnabled(true);
            bt_paste.setEnabled(true);
        }
    }//方法checkMenuItemEnabled()结束
//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$实现MouseListener接口中的方法
    public void mouseClicked(MouseEvent e) {
        checkMenuItemEnabled();
    }

    public void mouseEntered(MouseEvent e) {

    }

    public void mouseExited(MouseEvent e) {
        checkMenuItemEnabled();
    }

    public void mousePressed(MouseEvent e) {

    }

    public void mouseReleased(MouseEvent e) {//显示右键菜单
        if (e.isPopupTrigger())// getY() 返回事件相对于源组件的垂直 y 坐标。 int getYOnScreen() 返回事件的绝对垂直 y 坐标。
        //此处用前者会出现菜单位置问题
        {
            popupMenu.show(this, e.getXOnScreen(), e.getYOnScreen());
        }
    }

//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$实现DocumentListener接口中的方法
    public void changedUpdate(DocumentEvent arg0) {

        me1.setEnabled(true);
        popupMenu_Undo.setEnabled(true);
        bt_undo.setEnabled(true);

    }

    public void insertUpdate(DocumentEvent arg0) {

        me1.setEnabled(true);
        popupMenu_Undo.setEnabled(true);
        bt_undo.setEnabled(true);

    }

    public void removeUpdate(DocumentEvent arg0) {

        me1.setEnabled(true);
        popupMenu_Undo.setEnabled(true);
        bt_undo.setEnabled(true);

    }

//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

    //$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$实现Transferable接口的方法
    public Object getTransferData(DataFlavor arg0)
            throws UnsupportedFlavorException, IOException {
        // TODO 自动生成方法存根
        return null;
    }

    public DataFlavor[] getTransferDataFlavors() {
        // TODO 自动生成方法存根
        return null;
    }

    public boolean isDataFlavorSupported(DataFlavor arg0) {
        // TODO 自动生成方法存根
        return false;
    }
}

//DaveNotepad类结束$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
class JAVAFileFilter extends FileFilter {//实现文件过滤
    String ext;

    public JAVAFileFilter(String ext) {
        this.ext = ext;
    }

    public boolean accept(File file) {
        if (file.isDirectory()) {
            return true;
        }

        String fileName = file.getName();
        int index = fileName.lastIndexOf('.');

        if (index > 0 && index < fileName.length() - 1) {
            String extension = fileName.substring(index + 1).toLowerCase();
            if (extension.equals(ext)) {
                return true;
            }
        }
        return false;
    }

    public String getDescription() {
        if (ext.equals("txt")) {
            return "记事本文件(*.txt)";
        }
        if (ext.equals("c")) {
            return "C源文件 (*.c)";
        }
        if (ext.equals("cpp")) {
            return "C++源文件(*.cpp)";
        }
        if (ext.equals("sql")) {
            return "SQL文件(*.sql)";
        }
        if (ext.equals("doc")) {
            return "Word文档(*.doc)";
        }
        if (ext.equals("java")) {
            return "JAVA源文件 (*.java)";
        }
        if (ext.equals("class")) {