Charles Bell's HTMLDocumentEditor

HTMLDocumentEditor.java

/*	HTMLDocumentEditor.java
 *	@author: Charles Bell
 *	@version: May 27, 2002	
 */

import java.awt.*;
import java.awt.event.*;
import java.io.*;

import javax.swing.*;
import javax.swing.event.*;
import javax.swing.filechooser.*;
import javax.swing.text.*;
import javax.swing.text.html.*;
import javax.swing.undo.*;


public class HTMLDocumentEditor extends JFrame implements ActionListener{
	
	private HTMLDocument document;
	private JTextPane textPane = new JTextPane();
	private boolean debug = false;
	private File currentFile;
		
	/** Listener for the edits on the current document. */
	protected UndoableEditListener undoHandler = new UndoHandler();

	/** UndoManager that we add edits to. */
	protected UndoManager undo = new UndoManager();
		
	private UndoAction undoAction = new UndoAction();
	private RedoAction redoAction = new RedoAction();
		
	private Action cutAction = new DefaultEditorKit.CutAction();
	private Action copyAction = new DefaultEditorKit.CopyAction();
	private Action pasteAction = new DefaultEditorKit.PasteAction();

	private Action boldAction = new StyledEditorKit.BoldAction();
	private Action underlineAction = new StyledEditorKit.UnderlineAction();
	private Action italicAction = new StyledEditorKit.ItalicAction();
		
	private Action insertBreakAction = new DefaultEditorKit.InsertBreakAction();
	private HTMLEditorKit.InsertHTMLTextAction unorderedListAction 
		= new HTMLEditorKit.InsertHTMLTextAction("Bullets", "<ul><li> </li></ul>",HTML.Tag.P,HTML.Tag.UL);
	private HTMLEditorKit.InsertHTMLTextAction bulletAction 
		= new HTMLEditorKit.InsertHTMLTextAction("Bullets", "<li> </li>",HTML.Tag.UL,HTML.Tag.LI);

	public HTMLDocumentEditor(){
		super("HTMLDocumentEditor");
		HTMLEditorKit editorKit = new HTMLEditorKit();
		document = (HTMLDocument)editorKit.createDefaultDocument();
		// Force SwingSet to come up in the Cross Platform L&F
		try {
			//UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
			// If you want the System L&F instead, comment out the above line and
			// uncomment the following:
			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
		} catch (Exception exc) {
			    System.err.println("Error loading L&F: " + exc);
		}
		init();
	}
		
	public static void main(String[] args){
		HTMLDocumentEditor editor = new HTMLDocumentEditor();
	}
	
	public void init(){
		
		addWindowListener(new FrameListener());
		
		JMenuBar menuBar = new JMenuBar();
		getContentPane().add(menuBar, BorderLayout.NORTH);
		JMenu fileMenu = new JMenu("File");		
		JMenu editMenu = new JMenu("Edit");
		JMenu colorMenu = new JMenu("Color");		
		JMenu fontMenu = new JMenu("Font");		
		JMenu styleMenu = new JMenu("Style");	
		JMenu alignMenu = new JMenu("Align");
		JMenu helpMenu = new JMenu("Help");
		
		menuBar.add(fileMenu);
		menuBar.add(editMenu);
		menuBar.add(colorMenu);
		menuBar.add(fontMenu);
		menuBar.add(styleMenu);
		menuBar.add(alignMenu);
		menuBar.add(helpMenu);
		
		JMenuItem newItem = new JMenuItem("New", new ImageIcon("whatsnew-bang.gif"));
		JMenuItem openItem = new JMenuItem("Open",new ImageIcon("open.gif"));
		JMenuItem saveItem = new JMenuItem("Save",new ImageIcon("save.gif"));
		JMenuItem saveAsItem = new JMenuItem("Save As");
		JMenuItem exitItem = new JMenuItem("Exit",new ImageIcon("exit.gif"));
		
		newItem.addActionListener(this);
		openItem.addActionListener(this);
		saveItem.addActionListener(this);
		saveAsItem.addActionListener(this);
		exitItem.addActionListener(this);
		
		fileMenu.add(newItem);
		fileMenu.add(openItem);
		fileMenu.add(saveItem);
		fileMenu.add(saveAsItem);
		fileMenu.add(exitItem);
		
		
		JMenuItem undoItem = new JMenuItem(undoAction);
		JMenuItem redoItem = new JMenuItem(redoAction);
		JMenuItem cutItem = new JMenuItem(cutAction);
		JMenuItem copyItem = new JMenuItem(copyAction);
		JMenuItem pasteItem = new JMenuItem(pasteAction);
		JMenuItem clearItem = new JMenuItem("Clear");
		JMenuItem selectAllItem = new JMenuItem("Select All");
		JMenuItem insertBreaKItem = new JMenuItem(insertBreakAction);
		JMenuItem unorderedListItem = new JMenuItem(unorderedListAction);
		JMenuItem bulletItem = new JMenuItem(bulletAction);

		cutItem.setText("Cut");
		copyItem.setText("Copy");
		pasteItem.setText("Paste");
		insertBreaKItem.setText("Break");
		cutItem.setIcon(new ImageIcon("cut.gif"));
		copyItem.setIcon(new ImageIcon("copy.gif"));
		pasteItem.setIcon(new ImageIcon("paste.gif"));
		insertBreaKItem.setIcon(new ImageIcon("break.gif"));
		unorderedListItem.setIcon(new ImageIcon("bullets.gif"));
		
		clearItem.addActionListener(this);
		selectAllItem.addActionListener(this);
		
		editMenu.add(undoItem);
		editMenu.add(redoItem);
		editMenu.add(cutItem);
		editMenu.add(copyItem);
		editMenu.add(pasteItem);
		editMenu.add(clearItem);
		editMenu.add(selectAllItem);
		editMenu.add(insertBreaKItem);
		editMenu.add(unorderedListItem);
		editMenu.add(bulletItem);
		
		JMenuItem redTextItem = new JMenuItem(new StyledEditorKit.ForegroundAction("Red",Color.red));
		JMenuItem orangeTextItem = new JMenuItem(new StyledEditorKit.ForegroundAction("Orange",Color.orange));
		JMenuItem yellowTextItem = new JMenuItem(new StyledEditorKit.ForegroundAction("Yellow",Color.yellow));
		JMenuItem greenTextItem = new JMenuItem(new StyledEditorKit.ForegroundAction("Green",Color.green));
		JMenuItem blueTextItem = new JMenuItem(new StyledEditorKit.ForegroundAction("Blue",Color.blue));
		JMenuItem cyanTextItem = new JMenuItem(new StyledEditorKit.ForegroundAction("Cyan",Color.cyan));
		JMenuItem magentaTextItem = new JMenuItem(new StyledEditorKit.ForegroundAction("Magenta",Color.magenta));
		JMenuItem blackTextItem = new JMenuItem(new StyledEditorKit.ForegroundAction("Black",Color.black));

		redTextItem.setIcon(new ImageIcon("red.gif"));
		orangeTextItem.setIcon(new ImageIcon("orange.gif"));
		yellowTextItem.setIcon(new ImageIcon("yellow.gif"));
		greenTextItem.setIcon(new ImageIcon("green.gif"));
		blueTextItem.setIcon(new ImageIcon("blue.gif"));
		cyanTextItem.setIcon(new ImageIcon("cyan.gif"));
		magentaTextItem.setIcon(new ImageIcon("magenta.gif"));
		blackTextItem.setIcon(new ImageIcon("black.gif"));

		colorMenu.add(redTextItem);
		colorMenu.add(orangeTextItem);
		colorMenu.add(yellowTextItem);
		colorMenu.add(greenTextItem);
		colorMenu.add(blueTextItem);
		colorMenu.add(cyanTextItem);
		colorMenu.add(magentaTextItem);
		colorMenu.add(blackTextItem);

		JMenu fontTypeMenu = new JMenu("Font Type");
		fontMenu.add(fontTypeMenu);
		
		String[] fontTypes = {"SansSerif", "Serif", "Monospaced", "Dialog", "DialogInput"};
		for (int i = 0; i < fontTypes.length;i++){
			if (debug) System.out.println(fontTypes[i]);
			JMenuItem nextTypeItem = new JMenuItem(fontTypes[i]);
			nextTypeItem.setAction(new StyledEditorKit.FontFamilyAction(fontTypes[i], fontTypes[i]));
			fontTypeMenu.add(nextTypeItem);
		}

		JMenu fontSizeMenu = new JMenu("Font Size");
		fontMenu.add(fontSizeMenu);

		int[] fontSizes = {6, 8,10,12,14, 16, 20,24, 32,36,48,72};
		for (int i = 0; i < fontSizes.length;i++){
			if (debug) System.out.println(fontSizes[i]);
			JMenuItem nextSizeItem = new JMenuItem(String.valueOf(fontSizes[i]));
			nextSizeItem.setAction(new StyledEditorKit.FontSizeAction(String.valueOf(fontSizes[i]), fontSizes[i]));
			fontSizeMenu.add(nextSizeItem);
		}

		
		JMenuItem boldMenuItem = new JMenuItem(boldAction);
		JMenuItem underlineMenuItem = new JMenuItem(underlineAction);
		JMenuItem italicMenuItem = new JMenuItem(italicAction);
		
		boldMenuItem.setText("Bold");
		underlineMenuItem.setText("Underline");
		italicMenuItem.setText("Italic");

		boldMenuItem.setIcon(new ImageIcon("bold.gif"));
		underlineMenuItem.setIcon(new ImageIcon("underline.gif"));
		italicMenuItem.setIcon(new ImageIcon("italic.gif"));		

		styleMenu.add(boldMenuItem);
		styleMenu.add(underlineMenuItem);
		styleMenu.add(italicMenuItem);
		
		JMenuItem subscriptMenuItem = new JMenuItem(new SubscriptAction());
		JMenuItem superscriptMenuItem = new JMenuItem(new SuperscriptAction());
		JMenuItem strikeThroughMenuItem = new JMenuItem(new StrikeThroughAction());

		subscriptMenuItem.setText("Subscript");
		superscriptMenuItem.setText("Superscript");
		strikeThroughMenuItem.setText("StrikeThrough");

		subscriptMenuItem.setIcon(new ImageIcon("subscript.gif"));
		superscriptMenuItem.setIcon(new ImageIcon("superscript.gif"));
		strikeThroughMenuItem.setIcon(new ImageIcon("strikethough.gif"));

		styleMenu.add(subscriptMenuItem);
		styleMenu.add(superscriptMenuItem);
		styleMenu.add(strikeThroughMenuItem);
		
		JMenuItem leftAlignMenuItem = new JMenuItem(new StyledEditorKit.AlignmentAction("Left Align",StyleConstants.ALIGN_LEFT));
		JMenuItem centerMenuItem = new JMenuItem(new StyledEditorKit.AlignmentAction("Center",StyleConstants.ALIGN_CENTER));
		JMenuItem rightAlignMenuItem = new JMenuItem(new StyledEditorKit.AlignmentAction ("Right Align",StyleConstants.ALIGN_RIGHT));

		leftAlignMenuItem.setText("Left Align");
		centerMenuItem.setText("Center");
		rightAlignMenuItem.setText("Right Align");

		leftAlignMenuItem.setIcon(new ImageIcon("left.gif"));
		centerMenuItem.setIcon(new ImageIcon("center.gif"));
		rightAlignMenuItem.setIcon(new ImageIcon("right.gif"));

		alignMenu.add(leftAlignMenuItem);
		alignMenu.add(centerMenuItem);
		alignMenu.add(rightAlignMenuItem);

		JMenuItem helpItem = new JMenuItem("Help");
		helpItem.addActionListener(this);		
		helpMenu.add(helpItem);

		JMenuItem shortcutsItem = new JMenuItem("Keyboard Shortcuts");
		shortcutsItem.addActionListener(this);		
		helpMenu.add(shortcutsItem);

		JMenuItem aboutItem = new JMenuItem("About QuantumHyperSpace");
		aboutItem.addActionListener(this);		
		helpMenu.add(aboutItem);


		JPanel editorControlPanel = new JPanel();
		//editorControlPanel.setLayout(new GridLayout(3,3));
		editorControlPanel.setLayout(new FlowLayout());

		/* JButtons */
		JButton cutButton = new JButton(cutAction);
		JButton copyButton = new JButton(copyAction);
		JButton pasteButton = new JButton(pasteAction);

		JButton boldButton = new JButton(boldAction);
		JButton underlineButton = new JButton(underlineAction);
		JButton italicButton = new JButton(italicAction);
		

		//JButton insertButton = new JButton(insertAction);
		//JButton insertBreakButton = new JButton(insertBreakAction);
		//JButton tabButton = new JButton(tabAction);
		
		cutButton.setText("Cut");
		copyButton.setText("Copy");
		pasteButton.setText("Paste");
		
		boldButton.setText("Bold");
		underlineButton.setText("Underline");
		italicButton.setText("Italic");
		
		//insertButton.setText("Insert");
		//insertBreakButton.setText("Insert Break");
		//tabButton.setText("Tab");

		cutButton.setIcon(new ImageIcon("cut.gif"));
		copyButton.setIcon(new ImageIcon("copy.gif"));
		pasteButton.setIcon(new ImageIcon("paste.gif"));

		boldButton.setIcon(new ImageIcon("bold.gif"));
		underlineButton.setIcon(new ImageIcon("underline.gif"));
		italicButton.setIcon(new ImageIcon("italic.gif"));
		
		editorControlPanel.add(cutButton);
		editorControlPanel.add(copyButton);
		editorControlPanel.add(pasteButton);
		
		editorControlPanel.add(boldButton);
		editorControlPanel.add(underlineButton);
		editorControlPanel.add(italicButton);


		//editorControlPanel.add(insertButton);
		//editorControlPanel.add(insertBreakButton);
		//editorControlPanel.add(tabButton);
			
		JButton subscriptButton = new JButton(new SubscriptAction());
		JButton superscriptButton = new JButton(new SuperscriptAction());
		JButton strikeThroughButton = new JButton(new StrikeThroughAction());

		subscriptButton.setIcon(new ImageIcon("subscript.gif"));
		superscriptButton.setIcon(new ImageIcon("superscript.gif"));
		strikeThroughButton.setIcon(new ImageIcon("strikethough.gif"));


		JPanel specialPanel = new JPanel();
		specialPanel.setLayout(new FlowLayout());

		specialPanel.add(subscriptButton);
		specialPanel.add(superscriptButton);
		specialPanel.add(strikeThroughButton);

		//JButton leftAlignButton = new JButton(new AlignLeftAction());
		//JButton centerButton = new JButton(new CenterAction());
		//JButton rightAlignButton = new JButton(new AlignRightAction());
		
		JButton leftAlignButton = new JButton(new StyledEditorKit.AlignmentAction("Left Align",StyleConstants.ALIGN_LEFT));
		JButton centerButton = new JButton(new StyledEditorKit.AlignmentAction("Center",StyleConstants.ALIGN_CENTER));
		JButton rightAlignButton = new JButton(new StyledEditorKit.AlignmentAction ("Right Align",StyleConstants.ALIGN_RIGHT));
		JButton colorButton = new JButton(new StyledEditorKit.AlignmentAction ("Right Align",StyleConstants.ALIGN_RIGHT));

		leftAlignButton.setIcon(new ImageIcon("left.gif"));
		centerButton.setIcon(new ImageIcon("center.gif"));
		rightAlignButton.setIcon(new ImageIcon("right.gif"));
		colorButton.setIcon(new ImageIcon("color.gif"));

		leftAlignButton.setText("Left Align");
		centerButton.setText("Center");
		rightAlignButton.setText("Right Align");
			
		JPanel alignPanel = new JPanel();
		alignPanel.setLayout(new FlowLayout());
		alignPanel.add(leftAlignButton);
		alignPanel.add(centerButton);
		alignPanel.add(rightAlignButton);

		document.addUndoableEditListener(undoHandler);
		resetUndoManager();

		textPane = new JTextPane(document);
		textPane.setContentType("text/html");
		JScrollPane scrollPane = new JScrollPane(textPane);
		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
		Dimension scrollPaneSize = new Dimension(5*screenSize.width/8,5*screenSize.height/8);
		scrollPane.setPreferredSize(scrollPaneSize);
		
		JPanel toolPanel = new JPanel();
		toolPanel.setLayout(new BorderLayout());
		toolPanel.add(editorControlPanel, BorderLayout.NORTH);	
		toolPanel.add(specialPanel, BorderLayout.CENTER);	
		toolPanel.add(alignPanel, BorderLayout.SOUTH);	
		getContentPane().add(menuBar, BorderLayout.NORTH);	
		//getContentPane().add(toolPanel, BorderLayout.CENTER);	
		getContentPane().add(scrollPane, BorderLayout.SOUTH);			
		pack();
		setLocationRelativeTo(null);
		startNewDocument();
		show();
	}
	
	public void actionPerformed(ActionEvent ae){
		String actionCommand = ae.getActionCommand();
		if (debug){
			int modifier = ae.getModifiers();
			long when = ae.getWhen();
			String parameter = ae.paramString();
			System.out.println("actionCommand: " + actionCommand);
			System.out.println("modifier: " + modifier);
			System.out.println("when: " + when);
			System.out.println("parameter: " + parameter);
		}
		if (actionCommand.compareTo("New") == 0){
			startNewDocument();
		} else if (actionCommand.compareTo("Open") == 0){
			openDocument();
		} else if (actionCommand.compareTo("Save") == 0){
			saveDocument();
		} else if (actionCommand.compareTo("Save As") == 0){
		        saveDocumentAs();
		} else if (actionCommand.compareTo("Exit") == 0){
			exit();
		} else if (actionCommand.compareTo("Clear") == 0){
			clear();
		} else if (actionCommand.compareTo("Select All") == 0){
			selectAll();
		} else if (actionCommand.compareTo("Help") == 0){
			help();
		} else if (actionCommand.compareTo("Keyboard Shortcuts") == 0){
			showShortcuts();
		} else if (actionCommand.compareTo("About QuantumHyperSpace") == 0){
			aboutQuantumHyperSpace();
		} 
	}
	 
	protected void resetUndoManager() {
		undo.discardAllEdits();
		undoAction.update();
		redoAction.update();
	}
	
	public void startNewDocument(){
		Document oldDoc = textPane.getDocument();
		if(oldDoc != null)
			oldDoc.removeUndoableEditListener(undoHandler);
		HTMLEditorKit editorKit = new HTMLEditorKit();
		document = (HTMLDocument)editorKit.createDefaultDocument();
		textPane.setDocument(document);	
		currentFile = null;
		setTitle("HTMLDocumentEditor");	
		textPane.getDocument().addUndoableEditListener(undoHandler);
		resetUndoManager();
	}

	public void openDocument(){
		try{
			File current = new File(".");
			JFileChooser chooser = new JFileChooser(current);
			chooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
			chooser.setFileFilter(new HTMLFileFilter());
			int approval = chooser.showSaveDialog(this);
			if (approval == JFileChooser.APPROVE_OPTION){
				currentFile = chooser.getSelectedFile();
				setTitle(currentFile.getName());	
				FileReader fr = new FileReader(currentFile);
				Document oldDoc = textPane.getDocument();
				if(oldDoc != null)
					    oldDoc.removeUndoableEditListener(undoHandler);
				HTMLEditorKit editorKit = new HTMLEditorKit();
				document = (HTMLDocument)editorKit.createDefaultDocument();
				editorKit.read(fr,document,0);
				document.addUndoableEditListener(undoHandler);
				textPane.setDocument(document);
				resetUndoManager();
			}
		}catch(BadLocationException ble){
			System.err.println("BadLocationException: " + ble.getMessage());			
		}catch(FileNotFoundException fnfe){
			System.err.println("FileNotFoundException: " + fnfe.getMessage());			
		}catch(IOException ioe){
			System.err.println("IOException: " + ioe.getMessage());
		}

	}

	public void saveDocument(){
		if (currentFile != null){
			try{
				FileWriter fw = new FileWriter(currentFile);
				fw.write(textPane.getText());
				fw.close();
			}catch(FileNotFoundException fnfe){
				System.err.println("FileNotFoundException: " + fnfe.getMessage());			
			}catch(IOException ioe){
				System.err.println("IOException: " + ioe.getMessage());
			}	
		}else{
			saveDocumentAs();
		}			
	}

	public void saveDocumentAs(){
		try{
			File current = new File(".");
			JFileChooser chooser = new JFileChooser(current);
			chooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
			chooser.setFileFilter(new HTMLFileFilter());
			int approval = chooser.showSaveDialog(this);
			if (approval == JFileChooser.APPROVE_OPTION){
				File newFile = chooser.getSelectedFile();
				if (newFile.exists()){
					String message = newFile.getAbsolutePath() 
						+ " already exists. \n"
						+ "Do you want to replace it?";
					if (JOptionPane.showConfirmDialog(this, message) == JOptionPane.YES_OPTION){	
						currentFile = newFile;
						setTitle(currentFile.getName());	
						FileWriter fw = new FileWriter(currentFile);
						fw.write(textPane.getText());
						fw.close();
						if (debug) System.out.println("Saved " + currentFile.getAbsolutePath());
					}
				}else{
					currentFile = new File(newFile.getAbsolutePath());
					setTitle(currentFile.getName());	
					FileWriter fw = new FileWriter(currentFile);
					fw.write(textPane.getText());
					fw.close();
					if (debug) System.out.println("Saved " + currentFile.getAbsolutePath());				
				}
			}
		}catch(FileNotFoundException fnfe){
			System.err.println("FileNotFoundException: " + fnfe.getMessage());			
		}catch(IOException ioe){
			System.err.println("IOException: " + ioe.getMessage());
		}
	}

	public void exit(){
		String exitMessage = "Are you sure you want to exit?";
		if (JOptionPane.showConfirmDialog(this, exitMessage) == JOptionPane.YES_OPTION){
			System.exit(0);
		}
	}

	public void clear(){
		startNewDocument();
	}

	public void selectAll(){
		textPane.selectAll();
	}
	
	public void help(){
		JOptionPane.showMessageDialog(this,"DocumentEditor.java\n" + 
			"Author: Charles Bell\n" + 
			"Version: May 25, 2002\n" + 
			"http://www.quantumhyperspace.com\n" + 
			"QuantumHyperSpace Programming Services");
	}
	
	public void showShortcuts(){
		String shortcuts  = "Navigate in    |  Tab\n" + 
			"Navigate out   |  Ctrl+Tab\n" +
			"Navigate out backwards    |  Shift+Ctrl+Tab\n" +
			"Move up/down a line    |  Up/Down Arrown\n" +
			"Move left/right a component or char    |  Left/Right Arrow\n" +
			"Move up/down one vertical block    |  PgUp/PgDn\n" +
			"Move to start/end of line    |  Home/End\n" +
			"Move to previous/next word    |  Ctrl+Left/Right Arrow\n" +
			"Move to start/end of data    |  Ctrl+Home/End\n" +
			"Move left/right one block    |  Ctrl+PgUp/PgDn\n" +
			"Select All    |  Ctrl+A\n" +
			"Extend selection up one line    |  Shift+Up Arrow\n" +
			"Extend selection down one line    |  Shift+Down Arrow\n" +
			"Extend selection to beginning of line    |  Shift+Home\n" +
			"Extend selection to end of line    |  Shift+End\n" +
			"Extend selection to beginning of data    |  Ctrl+Shift+Home\n" +
			"Extend selection to end of data    |  Ctrl+Shift+End\n" +
			"Extend selection left    |  Shift+Right Arrow\n" +
			"Extend selection right    |  Shift+Right Arrow\n" +
			"Extend selection up one vertical block    |  Shift+PgUp\n" +
			"Extend selection down one vertical block    |  Shift+PgDn\n" +
			"Extend selection left one block    |  Ctrl+Shift+PgUp\n" +
			"Extend selection right one block    |  Ctrl+Shift+PgDn\n" +
			"Extend selection left one word    |  Ctrl+Shift+Left Arrow\n" +
			"Extend selection right one word    |  Ctrl+Shift+Right Arrow\n";
		JOptionPane.showMessageDialog(this,shortcuts);
	}

	public void aboutQuantumHyperSpace(){
		JOptionPane.showMessageDialog(this,"QuantumHyperSpace Programming Services\n" + 
			"http://www.quantumhyperspace.com\n" + 
			"email: [email protected]\n" + 
			"                     or \n" + 
			"email: [email protected]\n",
		        "QuantumHyperSpace",JOptionPane.INFORMATION_MESSAGE, 
		        new ImageIcon("quantumhyperspace.gif"));
	}
	
	class FrameListener extends WindowAdapter{
		public void windowClosing(WindowEvent we){
			exit();
		}
	}
	
	class SubscriptAction extends StyledEditorKit.StyledTextAction{
	
		public SubscriptAction(){
			super(StyleConstants.Subscript.toString());
		}
		public void actionPerformed(ActionEvent ae){
			JEditorPane editor = getEditor(ae);
			if (editor != null) {
				StyledEditorKit kit = getStyledEditorKit(editor);
				MutableAttributeSet attr = kit.getInputAttributes();
				boolean subscript = (StyleConstants.isSubscript(attr)) ? false : true;
				SimpleAttributeSet sas = new SimpleAttributeSet();
				StyleConstants.setSubscript(sas, subscript);
				setCharacterAttributes(editor, sas, false);
			}
		}
	}
	
	class SuperscriptAction extends StyledEditorKit.StyledTextAction{
	
		public SuperscriptAction(){
			super(StyleConstants.Superscript.toString());
		}
		public void actionPerformed(ActionEvent ae){
			JEditorPane editor = getEditor(ae);
			if (editor != null) {
				StyledEditorKit kit = getStyledEditorKit(editor);
				MutableAttributeSet attr = kit.getInputAttributes();
				boolean superscript = (StyleConstants.isSuperscript(attr)) ? false : true;
				SimpleAttributeSet sas = new SimpleAttributeSet();
				StyleConstants.setSuperscript(sas, superscript);
				setCharacterAttributes(editor, sas, false);
			}			
		}
	}
	
	class StrikeThroughAction extends StyledEditorKit.StyledTextAction{
	
		public StrikeThroughAction(){
			super(StyleConstants.StrikeThrough.toString());
		}
		
		public void actionPerformed(ActionEvent ae){
			JEditorPane editor = getEditor(ae);
			if (editor != null) {
				StyledEditorKit kit = getStyledEditorKit(editor);
				MutableAttributeSet attr = kit.getInputAttributes();
				boolean strikeThrough = (StyleConstants.isStrikeThrough(attr)) ? false : true;
				SimpleAttributeSet sas = new SimpleAttributeSet();
				StyleConstants.setStrikeThrough(sas, strikeThrough);
				setCharacterAttributes(editor, sas, false);
			}			
		}
	}
	

	class HTMLFileFilter extends javax.swing.filechooser.FileFilter{
	
		public boolean accept(File f){
			return ((f.isDirectory()) ||(f.getName().toLowerCase().indexOf(".htm") > 0));
		}
		
		public String getDescription(){
			return "html";
		}
	}
	
	 class UndoHandler implements UndoableEditListener {

		/**
		 * Messaged when the Document has created an edit, the edit is
		 * added to <code>undo</code>, an instance of UndoManager.
		 */
		public void undoableEditHappened(UndoableEditEvent e) {
			undo.addEdit(e.getEdit());
			undoAction.update();
			redoAction.update();
		}
	}
	
	class UndoAction extends AbstractAction {
		public UndoAction() {
			super("Undo");
			setEnabled(false);
		}

		public void actionPerformed(ActionEvent e) {
			try {
				undo.undo();
			} catch (CannotUndoException ex) {
				System.out.println("Unable to undo: " + ex);
				ex.printStackTrace();
			}
			update();
			redoAction.update();
		}

		protected void update() {
			if(undo.canUndo()) {
				setEnabled(true);
				putValue(Action.NAME, undo.getUndoPresentationName());
			}else {
				setEnabled(false);
				putValue(Action.NAME, "Undo");
			}
		}
	}

	class RedoAction extends AbstractAction {
		
		public RedoAction() {
			super("Redo");
			setEnabled(false);
		}

		public void actionPerformed(ActionEvent e) {
			try {
				undo.redo();
			} catch (CannotRedoException ex) {
				System.err.println("Unable to redo: " + ex);
				ex.printStackTrace();
			}
			update();
			undoAction.update();
		}
	
		protected void update() {
			if(undo.canRedo()) {
				setEnabled(true);
				putValue(Action.NAME, undo.getRedoPresentationName());
			}else {
				setEnabled(false);
				putValue(Action.NAME, "Redo");
			}
		}
	}
}

Original source: http://www.artima.com/forums/flat.jsp?forum=1&thread=1276