通过单击另一个JPanel上的按钮从JPanel中擦除bufferedImage

Question

我只想尝试在一个面板中打开图像，然后单击另一个面板上的按钮以使该图像消失。

以下只是原始代码的缩短版本，解决了具体问题。

public class NahualProductionTest {

    public static void main(String[] args) {

        NahualImagesPanel nahualPanel1 = new NahualImagesPanel();
        NahualSettingsPanel nahualPanel2 = new NahualSettingsPanel();
        JFrame frame = new JFrame();
        frame.setLayout(new GridLayout(1,2));
        frame.add(nahualPanel1);
        frame.add(nahualPanel2);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(900,400);
        frame.setLocation(200,200);
        frame.setVisible(true);
    }
}

public class NahualSettingsPanel extends JPanel {

        private JButton button;
        private NahualImagesPanel images;

    public NahualSettingsPanel(){

        images = new NahualImagesPanel();
        button = new JButton("Add");
        add(button);

        button.addActionListener(
            new ActionListener(){

                public void actionPerformed(ActionEvent e){
                    if (e.getSource()==button)
                        images.setVoid();
                }
            }
        );
    }
}

public class NahualImagesPanel extends JPanel{

    private BufferedImage tempImage;
    private int width, height, x, y;
    private double wrate = 0;
    private double hrate = 0;
    private JButton load;
    private PicPanel pics;

    public NahualImagesPanel(){

        setLayout(new BorderLayout());
        pics = new PicPanel();
        pics.setBackground(Color.DARK_GRAY);
        JPanel commands = new JPanel();
        commands.setLayout(new GridLayout(1,1));
        load = new JButton("Add Image");
        commands.add(load);

        add(pics, BorderLayout.CENTER);
        add(commands, BorderLayout.SOUTH);

        load.addActionListener(
            new ActionListener(){

                public void actionPerformed(ActionEvent e1){

                    if (e1.getSource()==load){
                        try{
                            JFileChooser chooser = new JFileChooser();
                            chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
                            chooser.showOpenDialog(null);
                            tempImage = ImageIO.read(chooser.getSelectedFile());
                            rescale(tempImage);
                            repaint();
                        } catch (IOException exception){
                            exception.printStackTrace();
                            System.exit(1);
                        } catch (IllegalArgumentException iae){}
                    }
                }
            }
        );
    }

    public void setVoid(){
        tempImage = null; //tempImage is set to null but after repaint() the image is still there
        pics.revalidate();
        pics.repaint();
    }

    public void rescale(Image img){

        width = tempImage.getWidth();
        height = tempImage.getHeight();

        if (width>270 || height>250){
            if (width-270>height-250){
                wrate = (double) (width-270)/width;
                width = 270;
                height = height - (int) (wrate*height);
                x = 10;
                y = 15;
            } 
            if (width-270<height-250) {
                hrate = (double) (height-250)/height;
                height = 250;
                width = width - (int) (hrate*width);
                x = (300-width)/2;
                y = 15;
            }
        }
    }

    public class PicPanel extends JPanel{

        @Override
        public void paintComponent(Graphics g){

            super.paintComponent(g);
            System.out.println(tempImage);
            g.drawImage(tempImage, x, y, width, height, null);
            //System.out.println(tempImage);
        }
    }
}