Total no. of lines in JTextPane document and Increment them on "ENTER" key

Question

hello,
I wanted to know the total number of lines that a document has. I.e for example when I open a .java into my JTextPane, I wanted to know the total no. of lines the file has and I wanted to increment them when I press the enter key.
2. Even it is a plain document, i.e just typing in the JTextPane and when I press enter key the number of lines should get incrementing.
I am using this method , but un successful. Can any one help me?
public int getLines()
          Document doc = text.getDocument();
          Element map = doc.getDefaultRootElement();
          int n = map.getElementCount();
          Element lastLine = map.getElement(n-1);
          if ((lastLine.getEndOffset() - lastLine.getStartOffset()) > 1)
               return n;
          return n - 1;
where text = JTextPane
Any example source will be helpful.
Thanks

Answer 1

Your code looks correct. Here is the program I used to test it. You must be calling the getLines() method BEFORE the document is being updated.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
public class TestTextArea extends JFrame
     public TestTextArea()
          JPanel panel = new JPanel();
          setContentPane( panel );
          panel.setLayout( new BorderLayout() );
          final JTextPane textArea = new JTextPane();
          JScrollPane scrollPane = new JScrollPane( textArea );
          panel.add( scrollPane );
          JButton button = new JButton("Display Lines");
          panel.add( button, BorderLayout.SOUTH );
          button.addActionListener( new ActionListener()
               public void actionPerformed(ActionEvent e)
                    Document doc = textArea.getDocument();
                    Element map = doc.getDefaultRootElement();
                    int n = map.getElementCount();
                    Element line = map.getElement(n-1);
                    if (line.getEndOffset() - line.getStartOffset() == 1)
                         n--;
                    System.out.println( n );
                    textArea.requestFocus();
     public static void main(String[] args)
          TestTextArea frame = new TestTextArea();
          frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
          frame.pack();
          frame.setVisible(true);
}