Alternative text display in JTextPanel

Question

Is it possible to do something in JTextPanel similar to emoticons in MSN Messenger. Where if you type something like =) a smiley icon replaces that text. Yet if you call getText() it will still return you the String "=)". Also, once the smiley icon is formed, if you press delete, it will delete the whole =) icon and not just the ")".

Answer 1

well, to be clean, the solution should use the DocumentFilter to make modifications to the document. Here's an updated version including a fix for the adjacent TextReferences bug you found. You can just as easily change it back to use a custom Document.
Your problem with the infinite loop should be fairly easy to solve. The problem is that the insert code executes from the same method (insertString) regardless of who's calling it. You should change your updateAttributes method to call "remove" on the text to replace instead of "replace". Then, use a custom "insertStringNoParse" method in your Document that simply bypasses the spawning of your Parser thread.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
* Created on November 18, 2005
* @author Jaspre
public class TextPaneTest extends JFrame {
    private JTextPane pane;
    private DefaultStyledDocument doc;
    public TextPaneTest() {
        super("test");
        setSize(300, 300);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        doc = new DefaultStyledDocument();
        doc.setDocumentFilter(new TextReferenceFilter());
        pane = new JTextPane(doc);
        pane.setText("this is a sentence without text references");
        pane.addCaretListener(new TextReferenceCaretHandler());
        JButton button = new JButton("Make Reference");
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                makeReference();
        JScrollPane scr = new JScrollPane(pane);
        getContentPane().setLayout(new BorderLayout());
        getContentPane().add(scr);
        getContentPane().add(button, BorderLayout.NORTH);
        setVisible(true);
    private TextReference getTextReference(int off) {
          return (TextReference)doc.getCharacterElement(off).getAttributes().getAttribute(TextReference.NAME);
     * Puts a TextReference attribute on the selected text,
     * and switches the referenced text with the new display text.
     * The display text can be an arbitrary String, for instance
     * something pulled from a database.
    private void makeReference() {
        int mark = pane.getSelectionStart();
        int dot = pane.getSelectionEnd();
        if (mark != dot) {
             String ref = pane.getSelectedText();
             String display = "TEST";
             SimpleAttributeSet as = new SimpleAttributeSet();
            as.addAttribute(TextReference.NAME, new TextReference(ref, display));
            // Replace the current selection with the display
            //    text, and give the display text the custom attribute.
            // Later, we can lookup any TextReference strings in the document.
            try {
                doc.replace(mark, dot-mark, display, as);
            catch (Exception e) {
                e.printStackTrace();
     * Custom attribute that just holds the referenced
     * text and the display text so we can always retrieve
     * the reference.
    private static class TextReference {
         public static String NAME = "$reference";
        public String ref;
        public String display;
        public TextReference(String ref, String text) {
            this.ref = ref;
            this.display = text;
     * Custom DocumentFilter that knows to delete an entire
     * String if any character of the String has the TextReference
     * attribute.  This ensures that we don't leave any partial
     * TextReferences lying around.
     * This can be made optional by not using this document.  Use
     * any other StyledDocument if you don't want this functionality.
    private class TextReferenceFilter extends DocumentFilter {
        public void remove(DocumentFilter.FilterBypass fb, int off, int len) throws BadLocationException {
            TextReference ref = getTextReference(off);
            if (ref != null) {
                int dlen = doc.getLength();
                int soff = off;
                while (soff > 0 && ref.equals(getTextReference(soff))) {
                    soff--;
                soff++;
                int eoff = off;
                while (eoff < dlen && ref.equals(getTextReference(eoff))) {
                    eoff++;
                off = soff;
                len = eoff - soff;
            fb.remove(off, len);
     * Tracks the caret and makes it jump over any TextReference strings.
     * Also adjusts the selection to include/exclude the TextReference.
     * This is can be made optional by just not adding this CaretListener
     * to the JTextPane.
    private class TextReferenceCaretHandler implements CaretListener {
        private int lastDot;
        private boolean adjusting;
        public void caretUpdate(final CaretEvent e) {
             if (adjusting) {
                 return;
            adjusting = true;
             int dot = e.getDot();
            int mark = e.getMark();
            final boolean selection = dot != mark;
            if (!selection && dot == lastDot) {
                 return;
            if (dot < lastDot) {
                 TextReference ref = getTextReference(dot);
                 if (ref != null && dot > 0) {
                      do { dot--; }
                      while (dot > 0 && ref == getTextReference(dot));
                      dot++;
            else if (dot > lastDot) {
                int len = doc.getLength();
                TextReference ref = getTextReference(dot-1);
                 if (ref != null && dot < len) {
                      do { dot++; }
                     while (dot < len && ref == getTextReference(dot));
            lastDot = dot;
            if (dot != e.getDot()) {
                SwingUtilities.invokeLater(new Runnable() {
                    public void run() {
                        if (selection)
                            pane.moveCaretPosition(lastDot);
                        else
                            pane.setCaretPosition(lastDot);
                        adjusting = false;
            else {
                 adjusting = false;
    public static void main(String[] args) {
        try {
           new TextPaneTest();
        catch (Exception e) {
            e.printStackTrace();
}