How to copy bufferedImage

Question

I have written the following example to give something runnable of a problem I am having. When you press the button the controlWhichImage switches to 2. The problem is that when it switches from the original image to a copy the image disappears.

public class PainterDemo01 extends JPanel implements ActionListener {
    BufferedImage createdImage;
    BufferedImage img;
    int controlWhichImage;
    JFrame mainFrame;
    JButton changePicture;

    public PainterDemo01(){
        changePicture = new JButton("Press");
        changePicture.addActionListener(this);
        controlWhichImage = 1;
        mainFrame = new JFrame();
        mainFrame.add(this);
        this.add(changePicture);
        mainFrame.setPreferredSize(new Dimension(600,600));
        mainFrame.setVisible(true);
        mainFrame.pack();
       img = loadImage();       
    }

    public BufferedImage loadImage(){
        img = null;
        try {
            img = ImageIO.read(new File("/home/gerry/Desktop/100_0647.JPG"));
        } catch (IOException e){
            System.out.println("no file here");
        }
        return img;
    }

    @Override
    protected void paintComponent(Graphics g){
        super.paintComponent(g);        

      loadImage();  
        if (createdImage == null){
            this.createdImage = new BufferedImage(this.getWidth(),this.getHeight(), BufferedImage.TYPE_INT_ARGB);
        }

        Graphics g2 = this.createdImage.getGraphics();      

        if (controlWhichImage == 1){
                g2.drawImage(img,0,0,img.getWidth(),img.getHeight(),null);
                g.drawImage(img, 0,0,img.getWidth(),img.getHeight(),null);       
                g2.dispose();
            }
        if (controlWhichImage == 2){
                //Draw bufferedImage on to to JPanel
                g.drawImage(this.createdImage,this.createdImage.getWidth(),this.createdImage.getHeight(),null);
        }               
    }
    @Override
    public void actionPerformed(ActionEvent e){
        controlWhichImage = 2;
        repaint();
    }

    public static void main(String[] args) {
        // TODO code application logic here
             java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new PainterDemo01().setVisible(true);
            }
        });
    }    
}

score 1 · Answer 1 · edited May 23 '17 at 12:23

1

See this question if you want to know how to copy an BufferedImage: How to copy BufferedImage

edited May 23 '17 at 12:23

Community

1
1

answered Feb 14 '16 at 14:25

SilentStorm

149
1
2
10

score 1 · Answer 2 · answered Feb 14 '16 at 15:15

The problem is that getGraphics (or better named createGraphics) is called outside the if statement, also for 2, hence both causing a resource leak (as no g2.dispose is called), and also a clean slate.

    if (controlWhichImage == 1) {
        Graphics g2 = createdImage.getGraphics();      
        g2.drawImage(img,0,0,img.getWidth(),img.getHeight(),null);
        g2.dispose();
    }

Also do things like loading the image outside the paint code.

SatyaTNV · Answer 3 · 2016-02-14T14:25:39.917

0

Use img obj since its already instantiated but not createdImage obj, createdImage contains null since its just declared but not instantiated. If you use createdImage obj means if you perform any operation upon createdImage obj then you will get NullPointerException.

Graphics g2 = this.img.getGraphics();
---------

edited Feb 14 '16 at 14:25

answered Feb 14 '16 at 14:20

SatyaTNV

4,137
3
15
31

I tried that whith this.image and it still disappears but thank you. – Gerry Feb 14 '16 at 14:37
made these change, it still disappears. – Gerry Feb 14 '16 at 15:32
Thank you all for your answers – Gerry Feb 14 '16 at 17:25

score 0 · Accepted Answer · answered Feb 14 '16 at 17:19

0

Of course! You have to go and paint the image at the outskirts. Please use this

g.drawImage(this.createdImage, 0, 0, this.createdImage.getWidth(),this.createdImage.getHeight(),null);

answered Feb 14 '16 at 17:19

gpasch

2,672
3
10
12

How to copy bufferedImage

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