Developing a professional-looking login screen in Java Swing often requires moving beyond default components. By combining custom UI delegates, manual layout management, and refined visual properties, you can create a unique user experience. This example demonstrates how to structure a login window with custom input fields, interactive buttons, and a themed progress bar.

Core UI Setup

To create a frameless, centered window, we initialize the JFrame with setUndecorated(true) and calculate the screen coordinates manually. The components are placed using a absolute layout (null layout) for precise positioning on a custom background panel.

public class AuthWindow extends JFrame {
   private JTextField usernameField;
   private JPasswordField passwordField;
   private JProgressBar statusIndicator;
   private final Color primaryTheme = new Color(27, 67, 103);

   public AuthWindow() {
       super("Login");
       setSize(787, 589);
       setUndecorated(true);
       setLayout(null);
       centerWindow();
       initializeComponents();
   }
   
   private void centerWindow() {
       Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
       setLocation((screen.width - getWidth()) / 2, (screen.height - getHeight()) / 2);
   }
}
   

Interactive Password Field

To improve usability, you can implement a toggle visibility feature for password fields. By adding a listener to a trailing icon component, you can dynamically swap the echo character.

// Inside component initialization
passwordField = new JPasswordField();
JButton toggleButton = new JButton("Show");

toggleButton.addActionListener(e -> {
   if (passwordField.getEchoChar() == '*') {
       passwordField.setEchoChar((char) 0);
   } else {
       passwordField.setEchoChar('*');
   }
});
passwordField.putClientProperty("JTextField.trailingComponent", toggleButton);
   

Themed Progress Bar

You can create a dynamic progress bar by extending BasicProgressBarUI. This allows you to override the paintDeterminate method to change the color based on the current progress percentage, providing real-time visual feedback.

public class DynamicProgressBarUI extends BasicProgressBarUI {
   @Override
   protected void paintDeterminate(Graphics g, JComponent c) {
       int val = progressBar.getValue();
       Color statusColor = (val < 50) ? Color.ORANGE : Color.GREEN;
       progressBar.setForeground(statusColor);
       super.paintDeterminate(g, c);
   }
}
   

Advanced UI Customization

To achieve a polished aesthetic, the TextBorderUtlis class (extending LineBorder) utilizes Graphics2D and RenderingHints to enable anti-aliasing for rounded input fields. This ensures that the borders appear smooth on high-resolution displyas. Similarly, button transparency is managed by setting setContentAreaFilled(false) and setBorderPainted(false), allowing for custom background icons and rollover effects using a standard MouseAdapter.