javafilter.java

java文件注释过滤器,将文件中的注释过滤掉.

package homework;

/*
 * javaFilter.java
 * one additional file:
 *   MyStyledDocument
 */

import java.awt.*;
import java.awt.event.*;
import java.util.HashMap;

import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
import javax.swing.undo.*;
import java.io.*;

public class javaFilter extends JFrame {
    JFileChooser chooser;
    JTextPane textPane;
    AbstractDocument doc;
    String newline = "\n";
    HashMap actions;
    Component curComponet = this.getComponent(0);
    //is changed or not
    boolean changed;
    File file;
    MyStyledDocument cur;
    //undo helpers
    protected UndoAction undoAction;
    protected RedoAction redoAction;
    protected UndoManager undo = new UndoManager();
    DefaultEditorKit a = new DefaultEditorKit();

    public javaFilter() {
        //Create the text pane and configure it.

        changed = false;
        file = null;
        setTitle();
        chooser = new JFileChooser();
        textPane = new JTextPane(cur = new MyStyledDocument());
        textPane.setCaretPosition(0);
        textPane.setMargin(new Insets(5, 5, 5, 5));
        StyledDocument styledDoc = textPane.getStyledDocument();
        if (styledDoc instanceof AbstractDocument) {
            doc = (AbstractDocument) styledDoc;
            doc.setDocumentFilter(new DocumentFilter());
        } else {
            System.err.println(
                    "Text pane's document isn't an AbstractDocument!");
            System.exit( -1);
        }
        JScrollPane scrollPane = new JScrollPane(textPane);
        scrollPane.setPreferredSize(new Dimension(400, 400));

        //Create the status area.
        JPanel statusPane = new JPanel(new GridLayout(1, 1));
        CaretListenerLabel caretListenerLabel =
                new CaretListenerLabel("Caret Status");
        statusPane.add(caretListenerLabel);

        //Add the components.
        getContentPane().add(scrollPane, BorderLayout.CENTER);
        getContentPane().add(statusPane, BorderLayout.PAGE_END);

        //Set up the menu bar.
        createActionTable(textPane);
        JMenu fileMenu = createFileMenu();
        JMenu editMenu = createEditMenu();
        JMenu styleMenu = createStyleMenu();
        JMenu aboutMenu = createAboutMenu();

        JMenuBar mb = new JMenuBar();
        mb.add(fileMenu);
        mb.add(editMenu);
        mb.add(styleMenu);
        mb.add(aboutMenu);
        setJMenuBar(mb);

        //Add some key bindings.
        addBindings();

        //Start watching for undoable edits and caret changes.
        doc.addUndoableEditListener(new MyUndoableEditListener());
        textPane.addCaretListener(caretListenerLabel);
        addWindowListener(new closeAdapter());

    }

    public void setTitle() {
        setTitle("Java Filter      " + file);
    }

    class closeAdapter extends WindowAdapter {
        public void windowClosing(WindowEvent e) {
            if (changed) {
                int ret = JOptionPane.showConfirmDialog(null, "Save File?",
                        "Confirm", JOptionPane.YES_NO_OPTION);
                if (ret == JOptionPane.YES_OPTION) {
                    saveFile();
                    System.exit(0);
                } else if (ret == JOptionPane.NO_OPTION) {
                    System.exit(0);
                }
            } else {
                System.exit(0);
            }
        }

    }


    //This listens for and reports caret movements.
    protected class CaretListenerLabel extends JLabel implements CaretListener {
        public CaretListenerLabel(String label) {
            super(label);
        }

        //Might not be invoked from the event dispatching thread.
        public void caretUpdate(CaretEvent e) {
            changed = true;
            displaySelectionInfo(e.getDot(), e.getMark());
        }

        //This method can be invoked from any thread.  It
        //invokes the setText and modelToView methods, which
        //must run in the event dispatching thread. We use
        //invokeLater to schedule the code for execution
        //in the event dispatching thread.
        protected void displaySelectionInfo(final int dot,
                                            final int mark) {
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    if (dot == mark) { // no selection
                        try {
                            Rectangle caretCoords = textPane.modelToView(dot);
                            //Convert it to view coordinates.
                            setText("caret: text position: " + dot
                                    + ", view location = ["
                                    + caretCoords.x + ", "
                                    + caretCoords.y + "]"
                                    + newline);
                        } catch (BadLocationException ble) {
                            setText("caret: text position: " + dot + newline);
                        }
                    } else if (dot < mark) {
                        setText("selection from: " + dot
                                + " to " + mark + newline);
                    } else {
                        setText("selection from: " + mark
                                + " to " + dot + newline);
                    }
                }
            });
        }
    }


    //This one listens for edits that can be undone.
    protected class MyUndoableEditListener implements UndoableEditListener {
        public void undoableEditHappened(UndoableEditEvent e) {
            //Remember the edit and update the menus.
            undo.addEdit(e.getEdit());
            undoAction.updateUndoState();
            redoAction.updateRedoState();
        }
    }


    //Add a couple of emacs key bindings for navigation.
    protected void addBindings() {
        InputMap inputMap = textPane.getInputMap();

        //Ctrl-b to go backward one character
        KeyStroke key = KeyStroke.getKeyStroke(KeyEvent.VK_B, Event.CTRL_MASK);
        inputMap.put(key, DefaultEditorKit.backwardAction);

        //Ctrl-f to go forward one character
        key = KeyStroke.getKeyStroke(KeyEvent.VK_F, Event.CTRL_MASK);
        inputMap.put(key, DefaultEditorKit.forwardAction);

        //Ctrl-p to go up one line
        key = KeyStroke.getKeyStroke(KeyEvent.VK_P, Event.CTRL_MASK);
        inputMap.put(key, DefaultEditorKit.upAction);

        //Ctrl-n to go down one line
        key = KeyStroke.getKeyStroke(KeyEvent.VK_N, Event.CTRL_MASK);
        inputMap.put(key, DefaultEditorKit.downAction);
    }

    //Create the File menu.
    protected JMenu createFileMenu() {
        JMenu menu = new JMenu("File");

        //New , Open , Save and Exit are actions of my own creation.
        menu.add(new NewAction());
        menu.addSeparator();
        menu.add(new OpenAction());
        menu.add(new SaveAction());
        menu.add(new SaveAsAction());
        menu.addSeparator();
        menu.add(new ExitAction());
        return menu;
    }

    //Create the About menu.
    protected JMenu createAboutMenu() {
        JMenu menu = new JMenu("About");
        menu.add(new AboutAction());
        return menu;
    }

    //Create the edit menu.
    protected JMenu createEditMenu() {
        JMenu menu = new JMenu("Edit");
        //Undo and redo are actions of our own creation.
        undoAction = new UndoAction();
        menu.add(undoAction);
        redoAction = new RedoAction();
        menu.add(redoAction);
        menu.addSeparator();
        //These actions come from the default editor kit.
        //Get the ones we want and stick them in the menu.
        menu.add(getActionByName(DefaultEditorKit.cutAction));
        menu.add(getActionByName(DefaultEditorKit.copyAction));
        menu.add(getActionByName(DefaultEditorKit.pasteAction));
        menu.addSeparator();
        menu.add(getActionByName(DefaultEditorKit.selectAllAction));
        menu.add(new deleteCommentAction());
        return menu;
    }

    //Create the style menu.
    protected JMenu createStyleMenu() {
        JMenu menu = new JMenu("Style");

        Action action = new StyledEditorKit.BoldAction();
        action.putValue(Action.NAME, "Bold");
        menu.add(action);

        action = new StyledEditorKit.ItalicAction();
        action.putValue(Action.NAME, "Italic");
        menu.add(action);

        action = new StyledEditorKit.UnderlineAction();
        action.putValue(Action.NAME, "Underline");
        menu.add(action);

        menu.addSeparator();

        menu.add(new StyledEditorKit.FontSizeAction("12", 12));
        menu.add(new StyledEditorKit.FontSizeAction("14", 14));
        menu.add(new StyledEditorKit.FontSizeAction("18", 18));

        menu.addSeparator();

        menu.add(new StyledEditorKit.FontFamilyAction("Serif",
                "Serif"));
        menu.add(new StyledEditorKit.FontFamilyAction("SansSerif",
                "SansSerif"));

        menu.addSeparator();

        menu.add(new StyledEditorKit.ForegroundAction("Red",
                Color.red));
        menu.add(new StyledEditorKit.ForegroundAction("Green",
                Color.green));
        menu.add(new StyledEditorKit.ForegroundAction("Blue",
                Color.blue));
        menu.add(new StyledEditorKit.ForegroundAction("Black",
                Color.black));

        return menu;
    }

    protected SimpleAttributeSet[] initAttributes(int length) {
        //Hard-code some attributes.
        SimpleAttributeSet[] attrs = new SimpleAttributeSet[length];

        attrs[0] = new SimpleAttributeSet();
        StyleConstants.setFontFamily(attrs[0], "SansSerif");
        StyleConstants.setFontSize(attrs[0], 16);

        attrs[1] = new SimpleAttributeSet(attrs[0]);
        StyleConstants.setBold(attrs[1], true);

        attrs[2] = new SimpleAttributeSet(attrs[0]);
        StyleConstants.setItalic(attrs[2], true);

        attrs[3] = new SimpleAttributeSet(attrs[0]);
        StyleConstants.setFontSize(attrs[3], 20);

        attrs[4] = new SimpleAttributeSet(attrs[0]);
        StyleConstants.setFontSize(attrs[4], 12);

        attrs[5] = new SimpleAttributeSet(attrs[0]);
        StyleConstants.setForeground(attrs[5], Color.red);

        return attrs;
    }

    //The following two methods allow us to find an
    //action provided by the editor kit by its name.
    private void createActionTable(JTextComponent textComponent) {
        actions = new HashMap();
        Action[] actionsArray = textComponent.getActions();
        for (int i = 0; i < actionsArray.length; i++) {
            Action a = actionsArray[i];
            actions.put(a.getValue(Action.NAME), a);
        }
    }

    private Action getActionByName(String name) {
        return (Action) (actions.get(name));
    }

    // delete Comment Action
    class deleteCommentAction extends AbstractAction {
        deleteCommentAction() {
            super("Delete Comment");
            setEnabled(true);
        }

        public void actionPerformed(ActionEvent e) {
            StringBuffer content = new StringBuffer(textPane.getText());
            deleteinfo(content, 0);
            textPane.setText(new String(content));
        }
    }


    void deleteinfo(StringBuffer content, int pos) {
        for (int i = pos; i < content.length() - 1; i++) {
            int start = i;
            int end = i + 2;
            if (content.substring(start, start + 2).equals("//")) { //end index shoud be exclusive