Setting ScrollBars From Child Class

I have a JScrollPane which contains a JPanel that displays an image. I have a rubberband box which will zoom in on the image which works fine. The problem that I am having, is that I need to adjust the JScrollPane's sliders. From within the mouse listener, I zoom the image to the desired scale and after it has zoomed, I call the parent class, JScrollPane to set the sliders to the new ratio. Even though I call it after it has zoomed and I call revalidate, the JScrollPane still has the old values for the sliders and has not updated them. If anyone has any ideas, I would appreciate it.

For ratio.... I just converted the place where I zoomed to as a percentage rather than the exact pixels. So I would zoom in from the jpanel.... repaint the image to the panel, revalidate. I would then call the JScrollPane and set the slider values to, H=35%, V=27%.
I tried your suggestion on overriding getPreferredSize() but I could not get it to work.
I think this will demonstrate my problem a little better:
(from the image panel)
ZoomToBox(image); //scales image to correct zoom and paints to panel(works fine)
this.setPreferredSize(new Dimension(image.width, image.height));
this.revalidate();
jScrollPanel.revalidate();
System.out.println(image.getWidth() + " " + jScrollPanel.getHorizontalScrollBar().getMaximum());
what prints out is (567 1150) which tells me that even though the image has zoomed, the scrollbars have not yet been updated.... then on the next zoom it will display(1150 4602) always beeing one behind. I tried to force setPreferredSize, even tried to force setSize before displaying the values but the scrollpanel is always behind.
For some reason, I dont even know why I tried it, but if I create a new thread to set the scrollbars it works (most) of the time. I dont want to have to do it that way though.

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Attachments:
Forum1937225.png ‏146 KB

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