JTextField

[dubey vandana]

hi,
i hv some JTextField(jtf)s in which i hv some integer values. i want tht just by using "backsapce key" whatever value i delete that should get stored in that value even without pressing "enter" key. i am not able to acheive this by actionPerfomred neither by keyListener.
pl guide wth some egs.
Also i want that frm anywhere i should be able to cut, insert append the integers in that jtf and it should get stored.
pl rasap
thanx

[Manfred Leonhardt]

Hi Dubey,
The code below might help you out.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
class IntTextDocument extends PlainDocument
{
  public void insertString( int offSet, String str, AttributeSet a )
         throws BadLocationException
  {
    if( str == null) return;
    String oldString = getText( 0, offSet );
    String newString = oldString.substring( 0, offSet ) +
                       str + 
                       oldString.substring( offSet );
    try
    {
      Integer.parseInt( newString + "0" );
      super.insertString( offSet, str, a );
    }
    catch( NumberFormatException nfe ) {};
  }
};
class IntTextField extends JTextField
{
  public IntTextField( String defVal, int size )
  {
    super( defVal, size );
  }
  protected Document createDefaultModel()
  {
    return( new IntTextDocument() );
  }
  public boolean isValid()
  {
    try
    {
      Integer.parseInt( getText() );
      return( true );
    }
    catch( NumberFormatException nfe )
    {
      return( false );
    }
  }
  public int getValue()
  {
    try
    {
      return( Integer.parseInt( getText() ) );
    }
    catch( NumberFormatException nfe )
    {
      return( 0 );
    }
  }
}
public class ValidationTester extends JFrame
{
  private IntTextField itf;
  public ValidationTester()
  {
    setTitle( "Validation Test" );
    setSize( 400, 200 );
    addWindowListener(
      new WindowAdapter()
      {
        public void windowClosing( WindowEvent we )
        {
          System.exit( 0 );
        }
      });
    Container contentPane = getContentPane();
    itf = new IntTextField( "123", 10 );
    contentPane.add( itf, "North" );
    JButton b = new JButton( "Value" );
    b.addActionListener(
      new ActionListener()
      {
        public void actionPerformed( ActionEvent ae )
        {
          System.out.println( "TEXT: " + itf.getText() );
        }
      });
    contentPane.add( b, "South" );
  }
  public static void main(String[] args) 
  {
    ValidationTester vt = new ValidationTester();
    vt.setVisible( true );
  }
}

Enjoy,
Manfred.