Re: Scrolling around a panel with no components

Jarrick Chagma wrote:


I got the same result as John. Adding a call to setPreferredSize()
makes the scroll bars appear. There's no connection between your buffer
image and the JPanel otherwise. The JPanel doesn't know that you keep
allocating an image buffer, how could it?

       @Override
       public void componentResized(final ComponentEvent e) {
           Scrolling.this.buffer =
                 (BufferedImage)MyPanel.this.createImage(
                      MyPanel.this.getWidth() + 100,
                      MyPanel.this.getHeight() + 100);

          setPreferredSize( new Dimension( buffer.getWidth(),
                                        buffer.getHeight() ));

          MyPanel.this.render();
       }
});

But this causes an infinite loop, as the JPanel is now constantly
resized. It does prove that the preferred size is the issue however,
since the scroll bars appear. I think you should just make one large
image, not a new one on each resize, and then set the size of the JFrame
to be less so you can scroll around.