Switching Panels and good swing practice..Swi

Question

Hi all,
I have a GUI in which one of the panels needs to change, based on what "mode" the program is currently in.
I've written code to do this but am wondering if it is good practice and if there are any easier ways you can suggest.
In particular, the use of validate/+revalidate+ and repaint. And also how I can use pack, because last time I tried it didn't work that well.
Thanks,
KrimsonEagl
public class SwitchingPanels extends JFrame implements ActionListener {
     private JDesktopPane desktopPane;
     private JPanel buttonPanel;
     private JPanel buttonPanelMain;
     private JPanel currentPanel = new JPanel();
     private enum Mode {
          MODE1, MODE2, MODE3
     private Mode mode = Mode.MODE1;
     private Map<Mode, JPanel> buttonMap;
     public SwitchingPanels() {
          // Set up GUI.
          super("Switching Panels");
          setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
          setSize(1024, 768);
          desktopPane = new JDesktopPane();
          add(desktopPane, BorderLayout.CENTER);
          buttonPanel = new JPanel();
          buttonPanel.setBorder(BorderFactory.createEtchedBorder());
          BoxLayout layout = new BoxLayout(buttonPanel, BoxLayout.Y_AXIS);
          buttonPanel.setLayout(layout);
          buttonPanelMain = new JPanel();
          ButtonGroup buttons = new ButtonGroup();
          addToggleButton(buttonPanelMain, buttons, "Mode1");
          addToggleButton(buttonPanelMain, buttons, "Mode2");
          addToggleButton(buttonPanelMain, buttons, "Mode3");
          addButton(buttonPanelMain, "Quit");
          createButtonPanels();
          buttonPanel.add(buttonPanelMain);
          buttonPanel.add(new JSeparator(SwingConstants.HORIZONTAL));
          add(buttonPanel, BorderLayout.NORTH);
          setLocation(50, 50);
          setVisible(true);
          refreshButtons();
     private void createButtonPanels() {
          buttonMap = new HashMap<Mode, JPanel>();
          JPanel mode1Panel = new JPanel();
          addButton(mode1Panel, "1.1");
          addButton(mode1Panel, "1.2");
          buttonMap.put(Mode.MODE1, mode1Panel);
          JPanel mode2Panel = new JPanel();
          addButton(mode2Panel, "2.1");
          addButton(mode2Panel, "2.2");
          buttonMap.put(Mode.MODE2, mode2Panel);
          JPanel mode3Panel = new JPanel();
          addButton(mode3Panel, "3.1");
          addButton(mode3Panel, "3.2");
          buttonMap.put(Mode.MODE3, mode3Panel);
     private void refreshButtons() {
          buttonPanel.remove(currentPanel);
          currentPanel = buttonMap.get(mode);
          buttonPanel.add(currentPanel);
          buttonPanel.validate();
          buttonPanel.repaint();
     private JToggleButton addToggleButton(JPanel panel, ButtonGroup group,
               String name) {
          JToggleButton button = new JToggleButton(name);
          button.addActionListener(this);
          group.add(button);
          panel.add(button);
          return button;
     public void actionPerformed(ActionEvent e) {
          String cmd = e.getActionCommand();
          if (cmd.equals("Mode1")) {
               mode = Mode.MODE1;
               refreshButtons();
          } else if (cmd.equals("Mode2")) {
               mode = Mode.MODE2;
               refreshButtons();
          } else if (cmd.equals("Mode3")) {
               mode = Mode.MODE3;
               refreshButtons();
}

Answer 1

Look up the CardLayout as it is probably your best option here.
Best of luck!