Populating CardLayout JPanels with External classes

[fred2482]

Can someone let me know if you can populate a JPanel from an external class. I am using a main JFrame with a cardlayout full of JPanels. I want to add all of the buttons and populate the entire panel from an external class. In other words instead of using
JPanel card2 = new JPanel();
and initiating all of the components I would like use
LogonPanel card2 = new LogonPanel() where "LogonPanel" is a seperate class(object) that extends JPanel and all of the components are added.

public class Nascar implements ActionListener
{

	JPanel cards;
	final static String SIGNIN="Sign in";
	final static String EXIT="Exit";
	final static String FORGOTPASSWORD="Forgot your password?";
	Icon logo = new ImageIcon ("logo.//gif");


	public void addComponentToPane(Container pane)
	{
		JPanel card1 = new JPanel();
		JButton signIn = new JButton(SIGNIN, logo);
		signIn.setActionCommand(EXIT);
		signIn.addActionListener(this);
		card1.add(signIn);

		JButton forgotPassword = new JButton(FORGOTPASSWORD);
		forgotPassword.setActionCommand(EXIT);
		forgotPassword.addActionListener(this);




		card1.add(forgotPassword);



		LogonScreen card2 = new LogonScreen();


		cards=new JPanel(new CardLayout());
		cards.add(card1, SIGNIN);
		cards.add(card2, EXIT);

		pane.add(cards, BorderLayout.CENTER);
	}


	public void actionPerformed(ActionEvent event)
		{
		CardLayout cl = (CardLayout)(cards.getLayout());
		cl.show(cards, (String)event.getActionCommand());
		}










	private static void createAndShowGUI()
	{

		JFrame frame = new JFrame ("Nascar Challenge");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setIconImage(new ImageIcon("logo1.gif").getImage());
		frame.setSize(750, 750);
		frame.setLocationRelativeTo(null);


		Nascar nascar = new Nascar();
		nascar.addComponentToPane(frame.getContentPane());

		//frame.pack();
		frame.setVisible(true);
	}





	public static void main(String [] args)
	{
		createAndShowGUI();
	}






}

public class LogonScreen extends JPanel

{
	public LogonScreen()
	{

		JPanel logon = new JPanel();

		setLayout(new BorderLayout());
		
		JButton signIn = new JButton("Sign In");

		logon.add(signIn, BorderLayout.SOUTH);



	}
}

[Fubarable]

The short answer is: yes, no it can be done no problem.

So, what problems are you having when you try this?

[fred2482]

When I click the forgotPassword button it just gives me the empty JPanel. It creates the object but the button that was added in the LogonScreen object does not appear. I have tried revalidate, and repaint but no luck.

[Fubarable]

When I click the forgotPassword button it just gives me the empty JPanel. It creates the object but the button that was added in the LogonScreen object does not appear. I have tried revalidate, and repaint but no luck.

This has nothing to do with CardLayout or using separate classes and everything to do with the fact that you add nothing to the LogonScreen JPanel. Instead you add a JButton to a separate and distinct JPanel called "logon" and then do nothing with this JPanel.

So if you add your JButton to the actual panel, you'll see it:

class LogonScreen extends JPanel {
   
   public LogonScreen() {
      //JPanel logon = new JPanel();
      setLayout(new BorderLayout());
      JButton signIn = new JButton("Sign In");
      //logon.add(signIn, BorderLayout.SOUTH);
      add(signIn, BorderLayout.SOUTH);
   }
}

[fred2482]

Thanks so much, it makes perfect sense now.

[Fubarable]

You're quite welcome. Much luck and happy coding!