Updating a panel within a container

Question

I am attempting to update a panel within a container. I have tried to search the forum but couldn't find a solution. The codes are listed below. What am I doing wrong?
package test;
import java.awt.*;
import java.awt.Graphics;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.plaf.FontUIResource;
import javax.swing.plaf.ColorUIResource;
class Template1 extends JFrame {     
     private static final Dimension screenSize = Toolkit.getDefaultToolkit ().getScreenSize ();
     private JLabel numLockKey, capsLockKey, mode;
     protected Container pane;
     protected JPanel buttonPanel, basePanel;
     public Template1() {
          super("Soybean Candles -- Authorized Personnel Only");                
        buildLayout();       
          setSize(screenSize.width, screenSize.height);                    
             setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             setResizable(false);             
          show();                              
     private void buildLayout() {
          pane = getContentPane();
          pane.setLayout(new BorderLayout());          
          basePanel = new JPanel(new BorderLayout());
          basePanel.add(new JLabel(new ImageIcon("C:/GUI/Images/plogo.jpg")), BorderLayout.CENTER);
            pane.add(panel_1(), BorderLayout.NORTH);
            pane.add(basePanel, BorderLayout.CENTER);            
     private JPanel panel_1() {
          buttonPanel = new JPanel(new FlowLayout(FlowLayout.LEFT, 20, 10));          
          buttonPanel.setBackground(Color.decode("#526dad"));
          JButton buttons[] = new JButton[3];
          buttonPanel.add(createButton(buttons[0], "TIME CLOCK", new TestAction()));
          buttonPanel.add(createButton(buttons[1], "LOGIN", new LoginAction()));
          buttonPanel.add(createButton(buttons[2], "EXIT", new TestAction()));
          return buttonPanel;
     private JButton createButton(JButton btn, String displayTxt, AbstractAction action) {
          Dimension dim = new Dimension(100, 40);
          btn = new JButton(action);
          btn.setText(displayTxt);          
          btn.setPreferredSize(dim);
          btn.setMaximumSize(dim);
          btn.setMinimumSize(dim);
          btn.setBorder(BorderFactory.createLineBorder(Color.white, 2));
          btn.setBackground(Color.decode("#3e4b84"));
          btn.setForeground(Color.white);          
          btn.setFocusPainted(false);
          btn.setActionCommand(displayTxt);
          return btn;          
     private JPanel panel_2() {          
          basePanel = new JPanel(new BorderLayout());
          basePanel.add(new JLabel(new ImageIcon("C:/GUI/Images/plogo.jpg")), BorderLayout.CENTER);
          return basePanel;
     public static void main(String args[]) {
          UIManager.put("Label.font", new FontUIResource(new Font("Arial", Font.PLAIN, 12)));
          UIManager.put("Button.font", new FontUIResource(new Font("Arial", Font.PLAIN, 12)));
          Template1 tpl = new Template1();
     class TestAction extends AbstractAction {             
             public void actionPerformed(ActionEvent e) {
                  System.out.println("button pressed");
        class LoginAction extends AbstractAction {
             public void actionPerformed(ActionEvent e) {
                  basePanel.invalidate();
                basePanel = new JPanel();
               basePanel.add(new JLabel("test"));
               basePanel.repaint();               
}

Answer 1

You're creating a new panel every time an action is performed. That panel is never going to be visible unless you add it to the frame.
Either remove the old panel and add the new panel or add the label to the panel you already have without creating a new one. Then call validate on the whole frame, and it should work.