Get focus to the start of JFormattedTextField

Question

I create my JFormattedTextField like this:
       try{
             MaskFormatter formatter = new MaskFormatter( "######-####" );
             JFormattedTextField idNr = new JFormattedTextField(formatter);
        catch(ParseException idNr){System.out.println(idNr);}Its working fine but the only problem is that when a user selects the JFormattedTextField to fil it out the focus is gained in the midle instead of the start where it should be.... Like normally a TextField would do.Can anyone help me with this?

Answer 1

This is a small subclass that only works with the DefaultFormatter constructor. Basically, you need to add a FocusListener and MouseListener. When the TextField gains focus, set a flag. When the user clicks in the TextField with the mouse the first time, the flag will be set (focus event comes first). The mouseClicked method will be called. If the flag is set, set the caret position to the beginning.
If the user clicks in the text field after the field already has focus, move the caret to the mouse position as normal.
Chad
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.JFormattedTextField;
import javax.swing.text.DefaultFormatter;
public class JMaskField extends JFormattedTextField
implements FocusListener, MouseListener
     private boolean justGotFocus;
     public JMaskField(DefaultFormatter mask)
          super(mask);
          addFocusListener(this);
          addMouseListener(this);
          justGotFocus = false;
     public void focusLost(FocusEvent event)
          setBackground(Color.white);
     public void focusGained(FocusEvent event)
          setBackground(Color.green);
          justGotFocus = true;
     public void mouseClicked(MouseEvent event)
          if (justGotFocus == true)
               justGotFocus = false;
               setCaretPosition(0);
     public void mouseEntered(MouseEvent e) {}
     public void mouseExited(MouseEvent e) {}
     public void mousePressed(MouseEvent e) {}
     public void mouseReleased(MouseEvent e) {}