Ruler with line numbering and cury text underline

Question

Hi,
I've just started programming in java and as an exercise i was trying to make an simple text editor. Uptil now i've been able to make a textarea and a menu with items and such, but i have 2 things that i'm very curious about.
1. How can I make a vertical ruler with line numbers in it? (like in JBuilder/Eclipse editors) I'm planning on putting it next to the text so I can see at which line in the document i'm at.
2. How can I underline (mark) text with those curly lines you often see in applications? (i.e. Marking grammar and spelling errors in MS Word or marking programming errors in editors like JBuilder/Eclipse)
I hope that these things can be done in Java. If someone could help me out with this, i'd be very grateful.
Kayhne

Answer 1

Try this.
regards,
Stas
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import java.util.*;
class Test {
    public Test() {
        JFrame fr = new JFrame("TEST");
        fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JEditorPane pane = new JEditorPane();
        pane.setEditorKit(new NewEditorKit());
        pane.setText("test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test ");
        StyledDocument doc = (StyledDocument) pane.getDocument();
        MutableAttributeSet attr = new SimpleAttributeSet();
        StyleConstants.setLineSpacing(attr, 5f);
        doc.setParagraphAttributes(0, doc.getLength(), attr, false);
        JScrollPane sp = new JScrollPane(pane);
        fr.getContentPane().add(sp);
        fr.setSize(300, 300);
        fr.show();
    public static void main(String[] args) {
        Test test = new Test();
class NewEditorKit extends StyledEditorKit {
    public ViewFactory getViewFactory() {
        return new NewViewFactory();
class NewViewFactory implements ViewFactory {
    public View create(Element elem) {
        String kind = elem.getName();
        if (kind != null) {
            if (kind.equals(AbstractDocument.ContentElementName)) {
                return new JaggedLabelView(elem);
            else if (kind.equals(AbstractDocument.ParagraphElementName)) {
                return new ParagraphView(elem);
            else if (kind.equals(AbstractDocument.SectionElementName)) {
                return new BoxView(elem, View.Y_AXIS);
            else if (kind.equals(StyleConstants.ComponentElementName)) {
                return new ComponentView(elem);
            else if (kind.equals(StyleConstants.IconElementName)) {
                return new IconView(elem);
        // default to text display
        return new LabelView(elem);
class JaggedLabelView extends LabelView {
    public JaggedLabelView(Element elem) {
        super(elem);
    public void paint(Graphics g, Shape allocation) {
        super.paint(g, allocation);
        paintJaggedLine(g, allocation);
    public void paintJaggedLine(Graphics g, Shape a) {
        int y = (int) (a.getBounds().getY() + a.getBounds().getHeight());
        int x1 = (int) a.getBounds().getX();
        int x2 = (int) (a.getBounds().getX() + a.getBounds().getWidth());
        Color old = g.getColor();
        g.setColor(Color.red);
        for (int i = x1; i <= x2; i += 6) {
            g.drawArc(i + 3, y - 3, 3, 3, 0, 180);
            g.drawArc(i + 6, y - 3, 3, 3, 180, 181);
        g.setColor(old);
}