Trying to bring swing frame to front before taking a screenshot but getting artifacts

Question

I have a part of my app that takes a screenshot of a certain window but before I do so I want to bring the window to the front. This works fine on my Mac machine but when I tested it on in Windows XP on paralells the screenshot always has a greyed out area where the overlapping window was. It seems the screenshot is always taken while the window I want on top is being transfered to the top. Ive tried using both:

     frame.setVisible(true);
            and
     frame.setAlwaysOnTop(true);

Does anyone have a reasonable solution for this issue?

Answer 1

• You could add a delay the the thread that takes the screenshot.

• You could fire the screenshot from the frame when the it has gained focus:

  class ScreenshotShooter implements FocusListener  {
      public void focusGained( FocusEvent e ) {
          // smile..... 
          // you may add a sec of delay here just be be sure.
      }
      public void focusLost( FocusEvent e ) {}
   }
  
  
   FocusListener focusListener = new ScreenshotShooter();
   frame.addFocusListener( focusListener );
   frame.setVisible( true ); // should autofire
   frame.remoe( focusListener);
  

• You can do both.

Answer 2

If you are trying to take a screenshot of a window w painted by Java, you can just ask it to paint itself on a

BufferedImage bi = new BufferedImage(
    w.width, w.height, BufferedImage.TYPE_INT_RGB); 
Graphics g = bi.getGraphics();

by calling the windows' paint(g) method. You can then save the BufferedImage to a file. If you are grabbing an external window, then I believe Oscar Reyes has given you all the answers.