Update JScrollPane at runtime

Question

Hi, well my problem is that I have a few JTextFields and an empty JScrollPane, but when something happens (e.i. a JButton is pressed) the text in the JTextFields should be added to the JScrollPane, but instead of that only the text from the last JTextField (in the example JTextField2) is added one time, no matters how many times the button is pressed, so the problem is:
How to add all the elements (in this case JLabels with the text from the JTextFields)?
I guess that all the elements are added but the last one overlaps the others.
Example:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ScrollUpdate extends JFrame{
     JTextField text1;
     JTextField text2;
     JScrollPane scroll;
     public ScrollUpdate(){
          text1 = new JTextField("Text 1");
          text1.setPreferredSize(new Dimension(100,22));
          text2 = new JTextField("Text 2");
          text2.setPreferredSize(new Dimension(100,22));
          JPanel panel = (JPanel)getContentPane();
          panel.add(text1, BorderLayout.LINE_START);
          scroll = new JScrollPane();
          scroll.setPreferredSize(new Dimension(100,100));
          panel.add(scroll, BorderLayout.LINE_END);
          panel.add(text2, BorderLayout.CENTER);
          JButton update = new JButton("Update");
          update.addActionListener(new ActionListener(){
               public void actionPerformed(ActionEvent e){
                    JLabel texto1 = new JLabel(text1.getText());
                    texto1.setAlignmentX(CENTER_ALIGNMENT);
                    scroll.getViewport().add(texto1);
                    JLabel texto2 = new JLabel(text2.getText());
                    texto2.setAlignmentX(CENTER_ALIGNMENT);
                    scroll.getViewport().add(texto2);
                    scroll.getViewport().revalidate();
                    scroll.repaint();
          panel.add(update, BorderLayout.PAGE_END);
          pack();
          setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
          setLocationRelativeTo(null);
     public static void main(String args[]){
          java.awt.EventQueue.invokeLater(new Runnable() {
               public void run() {
                    try {
                         // Set System L&F
                         JFrame.setDefaultLookAndFeelDecorated(true);
                         JDialog.setDefaultLookAndFeelDecorated(true);
                         UIManager.setLookAndFeel(UIManager
                                   .getSystemLookAndFeelClassName());
                    } catch (ClassNotFoundException e) {
                          //handle exception
                    } catch (Exception e) {
                         try {
                              UIManager
                                        .setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
                         } catch (Exception f) {
                    ScrollUpdate fenster = new ScrollUpdate();
                    fenster.setVisible(true);
}

Answer 1

I think that your problem is that you're adding things directly to the viewport rather than to a JPanel that is viewed in the viewport, say one that uses a GridLayout(0, 1). For e.g.,
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ScrollUpdate extends JFrame {
  JTextField text1;
  JTextField text2;
  JScrollPane scroll;
  private JPanel innerScrolledPanel = new JPanel(new GridLayout(0, 1));
  public ScrollUpdate() {
    text1 = new JTextField("Text 1");
    text1.setPreferredSize(new Dimension(100, 22));
    text2 = new JTextField("Text 2");
    text2.setPreferredSize(new Dimension(100, 22));
    JPanel panel = (JPanel) getContentPane();
    panel.add(text1, BorderLayout.LINE_START);
    scroll = new JScrollPane(innerScrolledPanel);
    scroll.setPreferredSize(new Dimension(100, 100));
    panel.add(scroll, BorderLayout.LINE_END);
    panel.add(text2, BorderLayout.CENTER);
    JButton update = new JButton("Update");
    update.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        JLabel texto1 = new JLabel(text1.getText());
        texto1.setAlignmentX(CENTER_ALIGNMENT);
        innerScrolledPanel.add(texto1);
        JLabel texto2 = new JLabel(text2.getText());
        texto2.setAlignmentX(CENTER_ALIGNMENT);
        innerScrolledPanel.add(texto2);
        innerScrolledPanel.revalidate();
        scroll.repaint();
    panel.add(update, BorderLayout.PAGE_END);
    pack();
    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    setLocationRelativeTo(null);
  public static void main(String args[]) {
    java.awt.EventQueue.invokeLater(new Runnable() {
      public void run() {
        ScrollUpdate fenster = new ScrollUpdate();
        fenster.setVisible(true);
}