JFrame not moving

Question

I want my JFrame to move despite disabling Decorrations.

i added a mouseListener after some googling but still didnt help.

    public static void main(String[] args) {

        try {
            UIManager.setLookAndFeel(new FlatDarkLaf());
        } catch (Exception errorDesign) {
            logError(errorDesign);
        }

        JFrame frame = new JFrame();
        frame.setBounds(1600, 400, 500, 800);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        frame.setUndecorated(true);
        frame.setVisible(true);

        frame.addMouseListener(new MouseAdapter() {
            private Point mouseOffset;

            @Override
            public void mousePressed(MouseEvent e) {
                mouseOffset = e.getPoint();
            }

            @Override
            public void mouseDragged(MouseEvent e) {
                Point newLocation = e.getLocationOnScreen();
                newLocation.translate(-mouseOffset.x, -mouseOffset.y);
                frame.setLocation(newLocation);
            }

        });

    }

someone who knows what i did wrong?

Answer 1

frame.addMouseMotionListener() must be used to track motion events such as mouse dragged. The MouseAdapter already extends both MouseListener MouseMotionListener so we can save this into a variable and re-use it in frame.addMouseListener() and frame.addMouseMotionListener().

See the Java Tutorial for more help: https://docs.oracle.com/javase/tutorial/uiswing/events/mousemotionlistener.html

 public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(new FlatDarkLaf());
        } catch (Exception errorDesign) {
            logError(errorDesign);
        }

        JFrame frame = new JFrame();
        frame.setBounds(1600, 400, 500, 800);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        frame.setUndecorated(true);
        frame.setVisible(true);
        
        MouseAdapter mouseAdapter = new MouseAdapter() {
            private Point mouseOffset;

            @Override
            public void mousePressed(MouseEvent e) {
                mouseOffset = e.getPoint();
            }

            @Override
            public void mouseDragged(MouseEvent e) {
                Point newLocation = e.getLocationOnScreen();
                newLocation.translate(-mouseOffset.x, -mouseOffset.y);
                frame.setLocation(newLocation);
            }
        };
        
        frame.addMouseListener(mouseAdapter);
        frame.addMouseMotionListener(mouseAdapter);

    }