How do I hide the current JPanel and show a new one with a button in Java?

Question

I unfortunately have to use multiple windows in this program and I don't think CardLayout is going to work because I can't have any buttons constant between the different layouts. So I'm trying to code a button to hide the present JPanel (thePanel) and show a new one (thePlacebo). I'm trying to hide thePanel in an ActionListener like this: ``` frame.getContentPane().remove(thePanel); ``` I thought this would work, but it just freezes my program as soon as I hit the button. Here's a chunk of the code for context: ``` public class Reflexology1 extends JFrame{ JButton button1, button2; JButton movingButton; JTextArea textArea1; int buttonAClicked, buttonDClicked; private long _openTime = 0; private long _closeTime = 0; JPanel thePanel = new JPanel(); JPanel thePlacebo = new JPanel(); final JFrame frame = new JFrame("Reflexology"); public static void main(String[] args){ new Reflexology1(); } public Reflexology1(){ frame.setSize(600, 475); frame.setLocationRelativeTo(null); frame.setDefau…

Accepted Answer

After removing components from a container, it goes into the `invalidate` state. To bring it back to the `valid` state you have to `revalidate` and `repaint` that. In your case you are directly adding/removing components from `JFrame` so depending on the Java version you can do this :

```
frame.revalidate(); // For Java 1.7 or above
frame.getContentPane().validate(); // For Java 1.6 or below
frame.repaint();
```

Here is one working example for your help :

```
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Assignment
{
    private JFrame frame;
    private JPanel firstPanel;
    private JPanel secondPanel;

private JButton forwardButton;
    private JButton backButton;

private void displayGUI()
    {
        frame = new JFrame("Assignment");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

firstPanel = new JPanel();
        firstPanel.setOpaque(true);
        firstPanel.setBackground(Color.BLUE);

secondPanel = new JPanel();
        secondPanel.setOpaque(true);
        secondPanel.setBackground(Color.RED);

forwardButton = new JButton("Forward");
        forwardButton.addActionListener(new ActionListener()
        {
            @Override
            public void actionPerformed(ActionEvent ae)
            {
                frame.remove(firstPanel);
                frame.add(secondPanel);
                frame.revalidate(); // For Java 1.7 or above.
                // frame.getContentPane().validate(); // For Java 1.6 or below.
                frame.repaint();
            }
        });

backButton = new JButton("Back");
        backButton.addActionListener(new ActionListener()
        {
            @Override
            public void actionPerformed(ActionEvent ae)
            {
                frame.remove(secondPanel);
                frame.add(firstPanel);
                frame.revalidate(); // For Java 1.7 or above.
                // frame.getContentPane().validate(); // For Java 1.6 or below.
                frame.repaint();
            }
        });

firstPanel.add(forwardButton);
        secondPanel.add(backButton);

frame.add(firstPanel);
        frame.setSize(300, 300);
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            @Override
            public void run()
            {
                new Assignment().displayGUI();
            }
        });
    }
}
```

How do I hide the current JPanel and show a new one with a button in Java?

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