GridBagLayout with Panels

Question

In a nutshell I have five panels. The comboPanel contains a label and comboBox; objectPanel has a label and text field; filePanel and directPanel have a label, text field and button; buttonPanel has two buttons.
When the program is first run only the comboPanel is visible. If "Display object and filePanel" is selected from the comboBox then the objectPanel and filePanel are visible, else directPanel is visible. buttonPanel is visible no matter what is selected.
The problem is I am trying to add them to the GridBayLayout and have them display below one another which is why I am using gbc.gridwidth = GridBagConstraints.REMAINDER for each, however they are all showing up on the same line.
Thanks in advance
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class SMG3AuditInterface extends JFrame
    JComboBox comboBox;
    JLabel lblComponent, lblObjectName, lblFileName, lblDirectName;
    JTextField tfObjectName, tfFileName, tfDirectName;
    JButton btnSubmit, btnCancel, btnFileBrowse, btnDirectBrowse;
    JPanel comboPanel, objectPanel, filePanel, directPanel, buttonPanel;
    GridBagLayout gb;
    GridBagConstraints gbc;
    public SMG3AuditInterface()
    gb = new GridBagLayout();
    gbc = new GridBagConstraints();
    Container cp = getContentPane();
    cp.setLayout(gb);
    String components[] = {"Display directPanel",
        "Display object and filePanel"};
    comboBox = new JComboBox(components);
    comboBox.setSelectedIndex(-1);
    lblComponent = new JLabel("Component Type: ");
    comboPanel = new JPanel();
    comboPanel.add(lblComponent);
    comboPanel.add(comboBox);
    cp.add(comboPanel);
    lblObjectName = new JLabel("Object name: ");
    tfObjectName = new JTextField(20);
    objectPanel = new JPanel();
    objectPanel.add(lblObjectName);
    objectPanel.add(tfObjectName);
    cp.add(objectPanel);
    objectPanel.setVisible(false);
    lblFileName = new JLabel("XML Filename: ");
    tfFileName = new JTextField(20);
    btnFileBrowse = new JButton("Browse");
    filePanel = new JPanel();
    filePanel.add(lblFileName);
    filePanel.add(tfFileName);
    filePanel.add(btnFileBrowse);
    cp.add(filePanel);
    filePanel.setVisible(false);
    lblDirectName = new JLabel("XML Directory name: ");
    tfDirectName = new JTextField(20);
    btnDirectBrowse = new JButton("Browse");
    directPanel = new JPanel();
    directPanel.add(lblDirectName);
    directPanel.add(tfDirectName);
    directPanel.add(btnDirectBrowse);
    cp.add(directPanel);
    directPanel.setVisible(false);
    btnSubmit = new JButton("Submit");
    btnCancel = new JButton("Cancel");
    buttonPanel = new JPanel();
    buttonPanel.add(btnSubmit);
    buttonPanel.add(btnCancel);
    cp.add(buttonPanel);
    buttonPanel.setVisible(false);
    gbc.gridx = GridBagConstraints.RELATIVE;
    gbc.gridy = GridBagConstraints.RELATIVE;
    gbc.fill = GridBagConstraints.BOTH;
    gbc.ipadx = 0;
    gbc.ipady = 0;
    gbc.gridwidth = 3;
    gbc.gridheight = 1;
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gb.setConstraints(comboPanel, gbc);
    add(comboPanel);
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.gridheight = 1;
    gb.setConstraints(objectPanel, gbc);
    add(objectPanel);
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.gridheight = 2;
    gb.setConstraints(filePanel, gbc);
    add(filePanel);
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.gridheight = 2;
    gb.setConstraints(directPanel, gbc);
    add(directPanel);
    gbc.gridwidth = 2;
    gbc.gridheight = 1;
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gb.setConstraints(buttonPanel, gbc);
    add(buttonPanel);
    comboBox.addItemListener(new ItemListener()
       public void itemStateChanged(ItemEvent e)
          JComboBox cb = (JComboBox)e.getSource();
          String itemName = (String)cb.getSelectedItem();
          buttonPanel.setVisible(true);
          if (itemName == "Display object and filePanel")
             objectPanel.setVisible(true);
             filePanel.setVisible(true);
             directPanel.setVisible(false);
          else
             objectPanel.setVisible(false);
             filePanel.setVisible(false);
             directPanel.setVisible(true);
    public static void main(String[] args)
    SMG3AuditInterface ai = new SMG3AuditInterface();
    ai.setDefaultCloseOperation(ai.EXIT_ON_CLOSE);
    ai.setLocation(400, 300);
    ai.setPreferredSize(new Dimension(400,300));
    ai.pack();
    ai.show();
}

Answer 1

Here's an example:
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class SMG3Petes extends JPanel
    private static final String DIRECT_PANEL = "Display directPanel";
    private static final String OBJECT_FILE_PANEL = "Display object and filePanel";
    private static final String components[] =
        DIRECT_PANEL, OBJECT_FILE_PANEL
    private static final String SUBMIT = "Submit";
    private static final String CANCEL = "Cancel";
    private static final String EMPTY_PANEL = "Empty Panel";
    private JPanel centerPanel;
    private CardLayout cardlayout = new CardLayout();
    private JComboBox comboBox;
    private JButton submitBtn = new JButton(SUBMIT);
    private JButton cancelBtn = new JButton(CANCEL);
    private JTextField tfObjectName = new JTextField(20);
    private JTextField tfFileName = new JTextField(20);
    private JTextField tfDirectName = new JTextField(20);
    public SMG3Petes()
        int eb = 15;
        setBorder(BorderFactory.createEmptyBorder(eb, eb, eb, eb));
        setLayout(new BorderLayout());
        add(createBigCenterPanel(), BorderLayout.CENTER);
        add(createPageEndPanel(), BorderLayout.PAGE_END);
    private JPanel createBigCenterPanel()
        JPanel p = new JPanel();
        p.setLayout(cardlayout);
        p.add(new JPanel(), EMPTY_PANEL);
        p.add(createObjectFilePanel(), OBJECT_FILE_PANEL);
        p.add(createDirectPanel(), DIRECT_PANEL);
        centerPanel = p;
        return p;
    private JPanel createObjectFilePanel()
        JPanel p = new JPanel();
        p.setLayout(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.gridheight = 1;
        gbc.gridwidth = 1;
        gbc.weightx = 1;
        gbc.weighty = 1;
        gbc.insets = new Insets(5, 5, 5, 5);
        p.add(new JLabel("Object name: "), gbc);
        gbc.gridx = 1;
        gbc.gridwidth = 2;
        gbc.weightx = 2;
        p.add(tfObjectName, gbc);
        gbc.gridx = 3;
        gbc.gridwidth = 1;
        gbc.weightx = 1;
        p.add(new JLabel("   "));
        gbc.gridx = 0;
        gbc.gridy = 1;
        gbc.gridwidth = 1;
        gbc.weightx = 1;
        p.add(new JLabel("XML Filename: "), gbc);
        gbc.gridx = 1;
        gbc.gridwidth = 2;
        gbc.weightx = 2;
        p.add(tfFileName, gbc);
        gbc.gridx = 3;
        gbc.gridwidth = 1;
        gbc.weightx = 1;
        JButton browseBtn = new JButton("Browse");
        p.add(browseBtn, gbc);
        return p;
    private JPanel createDirectPanel()
        JPanel p = new JPanel(new FlowLayout(FlowLayout.CENTER, 25, 0));
        JLabel lblDirectName = new JLabel("XML Directory name: ");
        tfDirectName = new JTextField(20);
        JButton btnDirectBrowse = new JButton("Browse");
        p.add(lblDirectName);
        p.add(tfDirectName);
        p.add(btnDirectBrowse);
        return p;
    private JPanel createPageEndPanel()
        JPanel p = new JPanel(new FlowLayout(FlowLayout.CENTER, 15, 0));
        p.add(createComboPanel());
        p.add(createButtonPanel());
        return p;
    private JPanel createComboPanel()
        comboBox = new JComboBox(components);
        comboBox.setSelectedIndex(-1);
        comboBox.addItemListener(new ComboItemListener());
        JPanel p = new JPanel();
        p.add(new JLabel("Component Type: "));
        p.add(comboBox);
        return p;
    private class ComboItemListener implements ItemListener
        public void itemStateChanged(ItemEvent ie)
            submitBtn.setEnabled(true);
            cancelBtn.setEnabled(true);
            String itemName = (String) comboBox.getSelectedItem();
            if (itemName.equals(DIRECT_PANEL))
                cardlayout.show(centerPanel, DIRECT_PANEL);
            else if (itemName.equals(OBJECT_FILE_PANEL))
                cardlayout.show(centerPanel, OBJECT_FILE_PANEL);
    private JPanel createButtonPanel()
        JPanel p = new JPanel(new GridLayout(1, 0, 15, 0));
        submitBtn.setEnabled(false);
        cancelBtn.setEnabled(false);
        p.add(submitBtn);
        p.add(cancelBtn);
        return p;
    private static void createAndShowGUI()
        JFrame frame = new JFrame("SMG3 Petes1234 Application");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(new SMG3Petes());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    public static void main(String[] args)
        javax.swing.SwingUtilities.invokeLater(new Runnable()
            public void run()
                createAndShowGUI();
}