Linking Java panels

Question

Hi
i cannot figure out how to link JPanels. How can i link JPanel to another JPanel when i click a JButton, i should go to another JPanel. I dont get how to set the "PATH".
Thankx
Sman

Answer 1

Don't know exactly what you want to do but: if you want a button in a panel ("first") be aware of another panel ("second") you have to ensure first has a reference to second.
The simple solution: create second before you create first and give first a reference to second. When the button in first is pressed, use the reference to second to do something with it.
//Code somewhere for laying out the panels and the rest of the gui
SecondPanel second = new SecondPanel();
FirstPanel first = new FirstPanel(second);
/** A panel class that can be "notified" to do something */
public class SecondPanel extends JPanel {
  public SecondPanel () {
  public void doSomething() {
    //do something here
/** A panel class with a button that "notifies" another panel when the button is pressed */
public class FirstPanel extends JPanel implements ActionListener {
  private SecondPanel secondPanel;
  private JButton button;
  public FirstPanel(SecondPanel aSecondPanel) {
    secondPanel = aSecondPanel;
    button = new JButton("Press me");
    button.addActionListener(this);
  public void actionPerformed(Actionevent ae) {
    secondPanel.doSomething();
}If you want your classes to be somewhat reusable, you probably should use some kind of abstrction (enables you to simply add "another" JPanel type instead of SecondPanel if nessecary). Below an example of accomplishing this with an interface any class can implement:
public interface Doable {
  public void doSomething();
public class SecondPanel extends JPanel implements Doable {
  public void doSomething() { ... }
public class ThirdPanel extends JPanel implements Doable {
  public void doSomething() { ... }
public class FirstPanel extends JPanel implements ActionListener {
  private Doable doable;
  private JButton button;
  public FirstPanel(Doable aDoable) {
    doable = aDoable;
    button = new JButton("Press me");
    button.addActionListener(this);
  public void actionPerformed(Actionevent ae) {
    doable.doSomething();
//Code somewhere for laying out the panels and the rest of the gui
Doable second = new SecondPanel();
Doable third = new ThirdPanel();
FirstPanel top = new FirstPanel(second);
FirstPanel bottom = new FirstPanel(third):
...