Go back to prior JPanel

Question

I have inherited code and for reasons to long to explain I am required to use a null layout. I have been attempting to take what they have an navigate between JPanels. I haven\'

Answer 1

I am required to use a null layout.

If you are asked by some mentor to perform navigation among panels using null layout, here is what you need to do:

• First, leave the mentor.
• Second, use CardLayout.

Check out the tutorial: How to use CardLayout

Working Example:

here is a written CardLayoutDemo which navigates among 10 panels including Home panel using button click action:

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

class CardLayoutDemo1 extends JFrame {

    private JPanel jPanel1;
    private JButton navHomeButt;
    private JButton navNextButt;
    private JButton navPreviousButt;
    private JPanel panelContainer;

    public CardLayoutDemo1() {
        initComponents();


        panelContainer.add(createSamplePanel("Home Panel "), ""+0);
        for(int i=1; i < 10; i++)
        {
           panelContainer.add(createSamplePanel("Panel "+i), ""+i);
        }
    }

    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        navPreviousButt = new JButton();
        navNextButt = new JButton();
        navHomeButt = new JButton();
        panelContainer = new JPanel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBackground(new java.awt.Color(255, 255, 255));

        navPreviousButt.setText("Previous");
        navPreviousButt.setPreferredSize(new Dimension(90, 23));
        jPanel1.add(navPreviousButt);

        navNextButt.setText("next");
        navNextButt.setPreferredSize(new Dimension(90, 23));
        jPanel1.add(navNextButt);

        navHomeButt.setText("Back to Home");
        jPanel1.add(navHomeButt);



        panelContainer.setPreferredSize(new Dimension(400, 300));
        panelContainer.setLayout(new CardLayout()); 
        // setting the card layout

        getContentPane().add(jPanel1, java.awt.BorderLayout.PAGE_END);
        getContentPane().add(panelContainer, BorderLayout.CENTER);




        navNextButt.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                CardLayout cardLayout = (CardLayout) panelContainer.getLayout();
                cardLayout.next(panelContainer);
                // using cardLayout next() to go  to next panel
            }
        });
        navHomeButt.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
               CardLayout cardLayout = (CardLayout) panelContainer.getLayout();
               cardLayout.first(panelContainer);
               // suing first to get to the home panel
            }
        });
        navPreviousButt.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
               CardLayout cardLayout = (CardLayout) panelContainer.getLayout();
               cardLayout.previous(panelContainer);

               // using previous to get to previous(left)panel
            }
        });

        pack();
    }                   

    public JPanel createSamplePanel(String panelTitle)
    {
        JPanel samplePanel = new JPanel();
        samplePanel.add(new JLabel(panelTitle));

        return samplePanel;

    }                                           


    public static void main(String args[]) {

        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new CardLayoutDemo1().setVisible(true);
            }
        });
    }

}