JTextPane displaying line numbers

Question

Hi,
I have a JTextPane that displays a certain text; I want to add to the left side of it a "sidebar" that displays a number for each line i.e.
1 | AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
30 | AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
60 | AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
90 | AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
The sidebar i mentioned is that with the numbers (1,30,60...). I want it to have a different color and when i copy the text i want to take only the AAAAA part and not the numbers.
Is there a JComponent i can add to the JTextPane or a method to highlight and make this "side text " non editable?
Thanks in advance for your help
Best Regards
Mubiol

Answer 1

Try this
best regards
Stas
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.text.rtf.*;
class Test extends JFrame
public Test()
super("Test");
JEditorPane edit = new JEditorPane();
edit.setEditorKit(new MyRTFEditorKit());
edit.setEditable(true);
JScrollPane scroll=new JScrollPane(edit);
getContentPane().add(scroll);
setSize(300,300);
setVisible(true);
public static void main(String a[])
new Test();
class MyRTFEditorKit extends RTFEditorKit
public ViewFactory getViewFactory()
return new MyRTFViewFactory();
class MyRTFViewFactory implements ViewFactory
public View create(Element elem)
String kind = elem.getName();
if (kind != null)
if (kind.equals(AbstractDocument.ContentElementName)) {
return new LabelView(elem);
} else if (kind.equals(AbstractDocument.ParagraphElementName)) {
// return new ParagraphView(elem);
return new MyParagraphView(elem);
} else if (kind.equals(AbstractDocument.SectionElementName)) {
// return new BoxView(elem, View.Y_AXIS);
return new MySectionView(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 MySectionView extends BoxView {
public MySectionView(Element e, int axis)
super(e,axis);
public void paintChild(Graphics g,Rectangle r,int n) {
if (n>0) {
MyParagraphView child=(MyParagraphView)this.getView(n-1);
int shift=child.shift+child.childCount;
MyParagraphView current=(MyParagraphView)this.getView(n);
current.shift=shift;
super.paintChild(g,r,n);
class MyParagraphView extends javax.swing.text.ParagraphView
public int childCount;
public int shift=0;
public MyParagraphView(Element e)
super(e);
short top=0;
short left=20;
short bottom=0;
short right=0;
this.setInsets(top,left,bottom,right);
public void paint(Graphics g, Shape a)
childCount=this.getViewCount();
super.paint (g,a);
int rowCountInThisParagraph=this.getViewCount(); //<----- YOU HAVE REAL ROW COUNT FOR ONE PARAGRAPH}
System.err.println(rowCountInThisParagraph);
public void paintChild(Graphics g,Rectangle r,int n) {
super.paintChild(g,r,n);
g.drawString(Integer.toString(shift+n+1),r.x-20,r.y+r.height-3);