How to reset JFrame in java

Question

I am a beginner to java. I have ImageFrame class as follows:

public class ImageFrame extends JFrame {
    private static final long serialVersionUID = 1L;

    public static final int DEFAULT_WIDTH = 1365;
    public static final int DEFAULT_HEIGHT = 730;

    GettingImage getimg = new GettingImage();
    private BufferedImage image = getimg.getImage();

    final ImageProcessing operation = new ImageProcessing(image);

    public ImageFrame(){
        setTitle("ImageTest");
        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

        JMenu process = new JMenu("Process");

        JMenuItem greyscale = new JMenuItem("greyscale");
        process.add(greyscale);

        //adding action listener to menu items
        greyscale.addActionListener(
            new ActionListener(){
                public void actionPerformed(ActionEvent e)
                {
                    image = operation.greyscale();
                    System.out.println("greyscale is pressed");  
                }
            }
        );

        JMenuBar bar = new JMenuBar();
        setJMenuBar(bar);
        bar.add(process);

        setSize(1365, 730);
        setVisible(true);

        ImageComponent component = new ImageComponent(image);
        add(component);
    }   
}

But the image is not converted into greyscale when I press the greyscale submenu but when I minimized the window and maximize it then the image is changed into greyscale. I think it is due to the fact that the window is not refreshed. How do I refresh it?

Answer 1

Call repaint on the ImageComponent in your action listener.