How to create off screen BufferedImage capture

[crikey]

suppose I wanted to create a BufferedImage, except it i would have to capture it on a window that is minimized. How should I do this? Thanks!

[Norm]

If the window is not showing, then the Robot class is no use.
An idea: Create a BufferedImage, get its graphics context and call the window's paint method to have it draw itself on your image.

[crikey]

If the window is not showing, then the Robot class is no use.
An idea: Create a BufferedImage, get its graphics context and call the window's paint method to have it draw itself on your image.

Thanks for your reply,
How should I do this? Can you give me an example?

[Norm]

Sorry, I don't have any examples.

[crikey]

any ideas? I'm stumped.

[Norm]

Have you tried what I suggested earlier:
Create a BufferedImage,
get its graphics context
call the window's paint method with the graphics to have it draw itself on your image.

Searching on this forum for new BufferedImage( found code examples for the first two steps.

The third step would be:
windowRef.paint(g); // for AWT
or
windowRef.paintComponent(g); // for swing

Now your buffered image contains what the window would have painted on the screen.
I don't know about the window's contained components. Try it and see what you get

[crikey]

Okay, This is how i paint a component:

 public static BufferedImage paintComponent(Graphics g) {
		 
		  BufferedImage grid = null;
		        x.paintComponents(g);       // paint background
		        Graphics2D g2 = (Graphics2D)g; // we need a Graphics2D context
		            int w = x.getWidth();
		            int h = x.getHeight();
                    grid = (BufferedImage)(x.createImage(w,h));


         return grid;
		  }

and here is how i call this method:

 Graphics g = x.getGraphics();
		BufferedImage picImageArea = paintComponent(g);
		try {

			ImageIO.write(picImageArea, "png", new File("test.png"));
		} catch (IOException e1) {
			e1.printStackTrace();
		}

When I see the saved image, I see nothing but white. "x" refers to another window that is opened. What is happening?

[Norm]

public static BufferedImage paintComponent(Graphics g) {

That is not the signature for the component's paintComponent method.
Are you intending to override the component's method?

    x.paintComponents(g);       // paint background

What is x???

What is happening?

I don't understand your code.
How does it relate to what I suggested?

The three steps:
BufferedImage bi = new BufferedImage( ....);
Graphics g = bi.getGraphics();

windowRef.paint(g); // have the window paint itself on our image