How can I get the card layout of an jInternalPane?

Question

I have a jInternalPane within a jDesktopPane . The jDesktopPane is within a jPanel that has the BorderLayout layout.

In my internal pane, I am trying to programatically switch cards. I have the following, relevant piece of code that breaks:

public void switchCards() {
    CardLayout cl = (CardLayout)(internalFrame1.getLayout());
    cl.show(internalFrame1, "card1"); //Where card1 is a jPanel
}

However, in the error trace, I can see the following:

javax.swing.plaf.basic.BasicInternalFrameUI$Handler cannot be cast to java.awt.CardLayout .

Can someone please point me in the right direction to properly handle this error? I would love to learn how to do it!

Many thanks in advance.

Answer 1

You would use a CardLayout on the content pane of the JInternalFrame, not the internal frame itself.

You can just set the layout of the content pane:

Container contentPane = internalFrame.getContentPane();
contentPane.setLayout( new CardLayout() );

contentPane.add(panel1, "Card1");
contentPane.add(panel2, "Card2");

Then your switchCards() method would be:

Container contentPane = internalFrame.getContentPane();
CardLayout cl = (CardLayout)(contentPane.getLayout());
cl.show(contentPane, "card1"); //Where card1 is a jPanel