Not able to repaint in java

Question

I am not able to dynamically repaint() inside the Jframe.

public static BufferedImage createBufferedImage(BufferedImage image) 
{
    ColorModel cm = image.getColorModel();
    boolean premultiplied = cm.isAlphaPremultiplied();
    WritableRaster raster = image.copyData(image.getRaster());
    return new BufferedImage(cm, raster, premultiplied, null);
}


public static void main(String[] args) {


BufferedImage img = new BufferedImage(old_width_i, old_height_i, BufferedImage.TYPE_INT_RGB);

img=createBufferedImage(img_white_screen);



JFrame frame=new JFrame();
JLabel label = new JLabel(new ImageIcon(img));
frame.getContentPane().add(label, BorderLayout.WEST);
frame.pack();
frame.setVisible(true); 
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


try {
    Thread.sleep(1000);
} catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

img.flush();
img=createBufferedImage(img_black_screen);
//  frame.removeAll();
//  frame.revalidate();
//  label.removeAll();
//  label = new JLabel(new ImageIcon(img));
//  frame.getContentPane().add(label, BorderLayout.WEST);

frame.repaint();
}

It basically, creates a screen with the first assignment to the "img" (i.e. img_white_screen) variable and does not change to the second assignment i.e. img_black_screen

use `label.setIcon(img)` after `img=createBufferedImage(img_black_screen);` . No need to repaint the JFrame. — Vishal K, Feb 09 '13 at 12:39
Sleeping on the EDT is a bad practice. It will lead to unpredictable behaviour. — Extreme Coders, Feb 09 '13 at 13:22

score 3 · Answer 1 · edited May 23 '17 at 12:27

3

don't to use Thread.sleep(1000);, this code line lock Event Dispatch Thread,
no idea for why reason you need to pause code execution for one second, use Swing Timer instead
for showing the Image in Java to use
1. XxxImage as Icon /IconImage to JLabel
2. paintComponent() for JComponent or JPanel
don't paint XxxImage or Icon / ImageIcon directly to the JFrame, use JPanel / JComponent or JLabel

edited May 23 '17 at 12:27

Community

1
1

answered Feb 09 '13 at 13:30

mKorbel

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I will be trying the posted answers, but the reason why I was using Sleep is to make the feeling of rotation... Say, the image was two circle having two different reference lines...I use, sleep so that user get a illusion of a wheel rotating.. any better solutions... NOTE:I am manually priting all the pixels values on the screen – JS_VIPER Feb 09 '13 at 19:31
@JS_VIPER for a [basic example](http://stackoverflow.com/questions/12593098/java-perform-action-every-x-seconds/12593132#12593132) – MadProgrammer Feb 09 '13 at 20:58

Not able to repaint in java

1 Answers1