How to Implement Full Screen Mode in Java on macOS

Question

How can I implement full screen mode in a Java application running on macOS?

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

public class FullScreenExample {
    public static void main(String[] args) {
        // Create a JFrame
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Set frame to full screen
        Frame[] frames = Frame.getFrames();
        for (Frame f : frames) {
            if (f.isDisplayable()) {
                GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
                GraphicsDevice gd = ge.getDefaultScreenDevice();
                gd.setFullScreenWindow(frame);
                break;
            }
        }
        // Add a label to the frame
        JLabel label = new JLabel('Full Screen Mode', SwingConstants.CENTER);
        frame.add(label);
        frame.setVisible(true);
    }
}

Answer

Implementing full screen mode in a Java application on macOS can enhance the user experience by utilizing the entire screen space. This guide provides a step-by-step approach to achieve full screen functionality using Java's AWT and Swing libraries.

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

public class FullScreenExample {
    public static void main(String[] args) {
        // Create a JFrame
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Set frame to full screen
        Frame[] frames = Frame.getFrames();
        for (Frame f : frames) {
            if (f.isDisplayable()) {
                GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
                GraphicsDevice gd = ge.getDefaultScreenDevice();
                gd.setFullScreenWindow(frame);
                break;
            }
        }
        // Add a label to the frame
        JLabel label = new JLabel('Full Screen Mode', SwingConstants.CENTER);
        frame.add(label);
        frame.setVisible(true);
    }
}

Causes

Not using the correct graphics device for full screen.
Forgetting to handle the full screen exit properly.

Solutions

Use `GraphicsEnvironment` and `GraphicsDevice` classes to switch to full screen mode.
Ensure your application properly exits full screen when needed.

Common Mistakes

Mistake: Forget to check if the frame is displayable before setting it to full screen.

Solution: Always verify that the frame is displayable to avoid runtime exceptions.

Mistake: Neglecting to provide a way to exit full screen mode.

Solution: Implement key listeners or buttons to allow users to exit full screen easily.

Helpers

Java full screen mode
Java macOS full screen
Java Swing full screen
GraphicsDevice full screen Java