Weird behavior after revalidate()

Question

hi everyone...
what im basically trying to do is when a text field looses focus another text field will be added to a panel....and i also have a button that will remove the buttons one after the other.....i am using the revalidate method for proper displaying of the scroll pane.
what is happening is when i press the remove button, text fields are added instead of getting removed...when i remove the revalidate method things runs smoothly except for the scroll pane....
what i think is happening is that when i press the button to remove a text field this removed field is loosing focus thus adding a new text field....this is only what i think is happening, it might not be true but either way i haven't been able to fix that....
this is the relevent part of the code :
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.util.ArrayList;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
* To change this template, choose Tools | Templates
* and open the template in the editor.
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
* @author fouad
public class test extends JFrame implements ActionListener{
    private JButton rem;
    private JPanel mainPanel,nPanel,cPanel,sPanel;
    private ArrayList<TestPanel> panels = new ArrayList<TestPanel>();
    private JScrollPane sp;
    private int count = 0;
    public test(){
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(1000, 600);
        mainPanel = new JPanel();
        nPanel= new JPanel();
        cPanel= new JPanel();
        sPanel= new JPanel();
        mainPanel.setLayout(new BorderLayout(5, 5));
        nPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
        sPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
        cPanel.setLayout(new BoxLayout(cPanel, BoxLayout.Y_AXIS));
        panels.add(new TestPanel(this));
        cPanel.add(panels.get(count));
        count++;
        sp = new JScrollPane(cPanel, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        rem = new JButton("remove");
        rem.setActionCommand("remove");
        rem.addActionListener(this);
        nPanel.add(rem);
        sPanel.setBackground(Color.yellow);
        sPanel.setPreferredSize(new Dimension(1000, 30));
        mainPanel.add(nPanel,BorderLayout.NORTH);
        mainPanel.add(sp,BorderLayout.CENTER);
        mainPanel.add(sPanel,BorderLayout.SOUTH);
        getContentPane().add(mainPanel);
    public void addItem(){
        panels.add(new TestPanel(this));
        cPanel.add(panels.get(count));
        panels.get(count).getField().requestFocus();
        count++;
        cPanel.revalidate();
    public static void main(String[] args){
        test t = new test();
        t.setVisible(true);
    public void actionPerformed(ActionEvent e) {
        if(e.getActionCommand().equalsIgnoreCase("remove")){
            if(count > 1){
                count--;
                cPanel.remove(panels.get(count -1));
                panels.remove(count-1);
                cPanel.revalidate();
class TestPanel extends JPanel implements FocusListener{
    private JTextField text = new JTextField(10);
    test t;
    public TestPanel(test t){
        this.t = t;
        setSize(900, 50);
        add(text);
        text.addFocusListener(this);
    public JTextField getField(){
        return text;
    public void focusGained(FocusEvent e) {
    public void focusLost(FocusEvent e) {
        t.addItem();
}please help
thanks in advance

Answer 1

thanks a lot....that was very helpful but the thing is,in this particular example, when you set the button to setFocusable(false) the button does not fire events anymore because when the text field looses focus the button does not get focus so it wont fires....but in my example i have more text fields so when i set the button to non focusable it kept on firing events because when the first text field lost focus the second one gained focus so the solution you provided solved my problem in my case....
thanks a lot