How do I access a gui component in a different class?

Question

I have a jpanel (mainwindow) in a japplet. mainwindow loads and displays a jpanel form (content1). How do I code a button on conent1 so that mainwindow loads and displays a different jpanel form(content2)? mainwindow, content1, and content2 are all in different classes/packages. Thanks in advance!

Answer 1

Let your JPanel content1 forward its ActionEvents to its parent. For instance, you could define your content1 as follows:
public class Content1 extends JPanel
    private ArrayList<ActionListener> actionListeners;
    private JButton myButton;
          public Content1()
         actionListeners = new ArrayList<ActionListener>();
         myButton = new JButton("Test");
         myButton.addActionListener(new ActionListener() {
                    public void actionPerformed(ActionEvent e) {
                         forwardAction(e);
          public void addActionListener(ActionListener listener) {
         actionListeners.add(listener);
    protected void forwardAction(ActionEvent e) {
      for (ActionListener l: actionListeners) {
           l.actionPerformed(e);
}Then you could let your mainWindow listen to content1:
// in your main windows' code:
Content1 content1 = new Content1();
content1.addActionListener(new ActionListener() {
     public void actionPerformed(ActionEvent e) {
          swapPane(e);    // create a method swapPane in your mainwindow that handles the switch to content2.
});