ChangeListener on scrollbar using zoom in button

Question

I'm a beginner in JavaSwing and JFreeChart. I have done an XYLineChart and I have add a scrollbar to this chart. I have done an SlidingXYDataset class like a SlidingCategoryDataset for my XYLineChart. And then my scrollbar works. This is the code:

JScrollBar scroller = new JScrollBar(JScrollBar.HORIZONTAL, 0, 10, 0, 20);

@Override
public void stateChanged(ChangeEvent e) {
    int value = scroller.getValue();
    dataset.setFirstItemIndex(value);
}

And now, I don't know how to adapt this scrollbar when I use the zoom. For my zoom, I have a button with an ActionListener. When I push the button, it triggers this code (in the constructor of my panel, the setMouseZoomable is false):

public class ZoomListener extends MouseAdapter{
    private SpectrumPanel specPanel;   
    private SpectrumController control;
    private ChartPanel panel;
    private JFreeChart chart;

    public ZoomListener(SpectrumController c){   
        control = c;
        specPanel = c.getSpectrumPanel();
        panel = c.getSpectrumChartPanel().getChartPanel();
        chart = c.getSpectrumChartPanel().getChartPanel().getChart();
    }

    @Override
    public void mousePressed(MouseEvent e) { 
        panel.setMouseZoomable(true);
    }

    @Override
    public void mouseExited(MouseEvent e) {
        panel.removeMouseListener(this);
        panel.setMouseZoomable(false);
        panel.setHorizontalAxisTrace(false);
        panel.setVerticalAxisTrace(false);

        specPanel.getGraphPanel().setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
    }
}

If you have ideas to link my scrollbar to the zoom, I'll take it with pleasure. Thank you for your help.