I would like to ask for help regarding code below.

Objectives:

I should be able to enlarge the JFrame to full screen whenever I’m dragging it to the top of the screen. Similarly if the JFrame is in full screen mode, whenever I drag it down it should return to the normal mode depends on the minimum size parameters.

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

public class DraggableFrame extends JFrame {
    private int posX = 0, posY = 0;
    private boolean isDraggingDown = false;

    public DraggableFrame() {
        // Initialize the JFrame
        setUndecorated(true);
        setSize(800, 600);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);

        // Add mouse listener for dragging
        addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                posX = e.getX();
                posY = e.getY();
                isDraggingDown = false;
            }
        });

        addMouseMotionListener(new MouseAdapter() {
            @Override
            public void mouseDragged(MouseEvent e) {
                int x = e.getXOnScreen() - posX;
                int y = e.getYOnScreen() - posY;

                // Handle dragging while in full screen
                if (getExtendedState() == JFrame.MAXIMIZED_BOTH) {
                    if (y > 0 && !isDraggingDown) {
                        isDraggingDown = true;
                        setExtendedState(JFrame.NORMAL);
                        setSize(800, 600); // Restore to initial size
                        setLocation(x, y);
                    } else if (y <= 0 && !isDraggingDown) {
                        // If the frame is dragged to the top while maximized, do nothing
                        return;
                    }
                } else {
                    setLocation(x, y);

                    // Check if dragged to the top
                    if (getY() <= 0) {
                        // Enlarge window to fullscreen without covering taskbar
                        GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
                        GraphicsDevice device = env.getDefaultScreenDevice();

                        Rectangle screenBounds = device.getDefaultConfiguration().getBounds();
                        Insets screenInsets = Toolkit.getDefaultToolkit().getScreenInsets(device.getDefaultConfiguration());

                        int taskbarHeight = screenInsets.bottom;

                        setBounds(screenBounds.x, screenBounds.y, screenBounds.width, screenBounds.height - taskbarHeight);
                    }
                }
            }
        });

        // Restore to normal size if dragged down while in fullscreen
        addMouseListener(new MouseAdapter() {
            @Override
            public void mouseReleased(MouseEvent e) {
                if (getY() == 0 && getExtendedState() == JFrame.MAXIMIZED_BOTH) {
                    setExtendedState(JFrame.NORMAL);
                    setSize(800, 600); // Restore to initial size
                    setLocationRelativeTo(null);
                }
            }
        });
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            DraggableFrame frame = new DraggableFrame();
            frame.setVisible(true);
        });
    }
}

I tried to apply some code that I found all over the internet but it seems none of them worked as I expected.

What I want is the following:

I should be able to enlarge the JFrame to full screen whenever I’m dragging it to the top of the screen. Similarly if the JFrame is in full screen mode, whenever I drag it down it should return to the normal mode depends on the minimum size parameters.