Zoom In and Zoom out functionality on a button cli

问题:

Basically i want the line graph to be zoomed in and Zoomed out(total 4 buttons,2 for X-axis(Zoom in and Zoom out) and other two for Y-axis) on a button click along any axis like if the graph drawn on negative x-axis and negative Y-axis area ,depending on data points then on button click the graph should be Zoomed in and Zoomed out along that negative x-axis or negative Y-axis based on button click.

How can i achieve this ?Any sample code with detail Explanation is much helpful!!

 private JButton createZoom()
 {
        final JButton auto = new JButton("ZOOMIN");
        auto.setActionCommand("ZOOM_IN_DOMAIN");
        auto.addActionListener(new ChartPanel(chart));
        return auto;
    }

回答1:

Each button's Action implementation should invoke the corresponding method used by ChartPanel to create it's popup menu of zoom commands. The implementation of actionPerformed() is a convenient guide to the available zooming functionality. For example, the ZOOM_IN_DOMAIN_COMMAND is handled by invoking zoomInDomain(). Based on this example, a typical Zoom X handler relative to the origin is shown below:

private JButton createZoom() {
    final JButton zoomX = new JButton(new AbstractAction("Zoom X") {

        @Override
        public void actionPerformed(ActionEvent e) {
            chartPanel.zoomInDomain(0, 0);
        }
    });
    return zoomX;
}

If the default zoomPoint is sufficient, you can use the chart panel's implementation:

private JButton createZoom() {
    final JButton zoomX = new JButton("Zoom X");
    zoomX.setActionCommand(ChartPanel.ZOOM_IN_DOMAIN_COMMAND);
    zoomX.addActionListener(chartPanel);
    return zoomX;
}

In contrast, the createZoom() method in the original example shows how to evoke the ChartPanel method restoreAutoBounds(), which restores the auto-range calculation on both axes.