panscrollzoomdemo.java

这是一个segy数据显示程序

                            && newMax <= hvp.getDataRange(xAxis).getUpperBound()) {
                            xAxis.setLowerBound(newMin);
                            xAxis.setUpperBound(newMax);
                        }
                    }
                }

                // vertical pan (1. Y-Axis)

                if (plot instanceof XYPlot) {
                    final XYPlot vvp = (XYPlot) plot;
                    final ValueAxis yAxis = vvp.getRangeAxis();

                    if (yAxis != null) {
                        final double translatedStartPoint = yAxis.java2DToValue(
                            (float) this.panStartPoint.getY(),
                            scaledDataArea,
                            vvp.getRangeAxisEdge()
                        );
                        final double translatedEndPoint = yAxis.java2DToValue(
                            (float) panEndPoint.getY(),
                            scaledDataArea,
                            vvp.getRangeAxisEdge()
                        );
                        final double dY = translatedStartPoint - translatedEndPoint;

                        final double oldMin = yAxis.getLowerBound();
                        final double newMin = oldMin + dY;

                        final double oldMax = yAxis.getUpperBound();
                        final double newMax = oldMax + dY;

                        // do not pan out of range
                        if (newMin >= this.primYMinMax[0] && newMax <= this.primYMinMax[1]) {
                            yAxis.setLowerBound(newMin);
                            yAxis.setUpperBound(newMax);
                        }
                    }
                }

                // vertical pan (2. Y-Axis)

                if (plot instanceof XYPlot) {
                    final XYPlot xyPlot = (XYPlot) plot;
                    final ValueAxis yAxis = xyPlot.getRangeAxis(1);

                    if (yAxis != null) {
                        final double translatedStartPoint = yAxis.java2DToValue(
                            (float) this.panStartPoint.getY(),
                            scaledDataArea,
                            xyPlot.getRangeAxisEdge(1)
                        );
                        final double translatedEndPoint = yAxis.java2DToValue(
                            (float) panEndPoint.getY(),
                            scaledDataArea,
                            xyPlot.getRangeAxisEdge(1)
                        );
                        final double dY = translatedStartPoint - translatedEndPoint;

                        final double oldMin = yAxis.getLowerBound();
                        final double newMin = oldMin + dY;

                        final double oldMax = yAxis.getUpperBound();
                        final double newMax = oldMax + dY;

                        if (newMin >= this.secondYMinMax[0] && newMax <= this.secondYMinMax[1]) {
                            yAxis.setLowerBound(newMin);
                            yAxis.setUpperBound(newMax);
                        }
                    }
                }

                // for the next time
                this.panStartPoint = panEndPoint;
            }
        } 
        catch (Exception e) {
            e.printStackTrace();
        }
    }

    /** 
     * Handles a mouse clicked event, in this case by ignoring it.
     * 
     * @param event  the event.
     */
    public void mouseClicked(final MouseEvent event) {
        // ignored
    }

    /** 
     * Handles a mouse moved event, in this case by ignoring it.
     * 
     * @param event  the event.
     */
    public void mouseMoved(final MouseEvent event) {
        // ignored
    }

    /** 
     * Handles a mouse entered event, in this case by ignoring it.
     * 
     * @param event  the event.
     */
    public void mouseEntered(final MouseEvent event) {
        // ignored
    }

    /** 
     * Handles a mouse exited event, in this case by ignoring it.
     * 
     * @param event  the event.
     */
    public void mouseExited(final MouseEvent event) {
        // ignored
    }

    /**
     * Starting point for the demo.
     * 
     * @param args  the command line arguments (ignored).
     */
    public static void main(final String[] args) {
        
        try {
            final String lookAndFeelClassName = WindowsLookAndFeel.class.getName();
            UIManager.setLookAndFeel(lookAndFeelClassName);
        } 
        catch (Exception ex) {
            System.out.println(ex.getMessage());
        }

        final PanScrollZoomDemo demo = new PanScrollZoomDemo("Pan & Scroll & Zoom - Demo");
        demo.pack();
        demo.setVisible(true);
    
    }

    // PRIVATE 
    
    /**
     * Recalculates the scrollbar settings.
     * 
     * @param plot  the plot.
     */
    private void recalcScrollBar(final Plot plot) {
        if (plot instanceof XYPlot) {
            final XYPlot hvp = (XYPlot) plot;
            final ValueAxis axis = hvp.getDomainAxis();

            axis.setLowerMargin(0);
            axis.setUpperMargin(0);

            final Range rng = axis.getRange();

            final BoundedRangeModel scrollBarModel = this.scrollBar.getModel();
            final int len = scrollBarModel.getMaximum() - scrollBarModel.getMinimum();
            if (rng.getLength() > 0) {
                this.scrollFactor = len / rng.getLength();
            }
            
            final double dblow = rng.getLowerBound();
            final int ilow = (int) (dblow * this.scrollFactor);
            scrollBarModel.setMinimum(ilow);
            final int val = ilow;
            scrollBarModel.setValue(val);

            final double dbup = rng.getUpperBound();
            final int iup = (int) (dbup * this.scrollFactor);
            scrollBarModel.setMaximum(iup);
            final int ext = iup - ilow;
            scrollBarModel.setExtent(ext);

            scrollBarModel.addChangeListener(this);
        }
    }

    /**
     * Zooms in on an anchor point (measured in Java2D coordinates).
     * 
     * @param x  the x value.
     * @param y  the y value.
     * @param zoomFactor  the zoomFactor < 1 == zoom in; else out.
     */
    private void zoomBoth(final double x, final double y, final double zoomFactor) {
        zoomHorizontal(x, zoomFactor);
        zoomVertical(y, zoomFactor);
    }

    /**
     * Decreases the range on the horizontal axis, centered about a Java2D x coordinate.
     * <P>
     * The range on the x axis is multiplied by zoomFactor
     * 
     * @param x  the x coordinate in Java2D space.
     * @param zoomFactor  the zoomFactor < 1 == zoom in; else out.
     */
    private void zoomHorizontal(final double x, final double zoomFactor) {

        final JFreeChart chart = this.chartPanel.getChart();
        final ChartRenderingInfo info = this.chartPanel.getChartRenderingInfo();
        if (chart.getPlot() instanceof XYPlot) {
            final XYPlot hvp = (XYPlot) chart.getPlot();
            final ValueAxis axis = hvp.getDomainAxis();
            if (axis != null) {
                final double anchorValue = axis.java2DToValue(
                    (float) x, info.getPlotInfo().getDataArea(), hvp.getDomainAxisEdge()
                );
                if (zoomFactor < 1.0) {
                    axis.resizeRange(zoomFactor, anchorValue);
                } 
                else if (zoomFactor > 1.0) {
                    final Range range = hvp.getDataRange(axis);
                    adjustRange(axis, range, zoomFactor, anchorValue);
                }
            }
        }
    }

    /**
     * Decreases the range on the vertical axis, centered about a Java2D y coordinate.
     * <P>
     * The range on the y axis is multiplied by zoomFactor
     * 
     * @param y  the y coordinate in Java2D space.
     * @param zoomFactor  the zoomFactor < 1 == zoom in; else out.
     */
    private void zoomVertical(final double y, final double zoomFactor) {

        final JFreeChart chart = this.chartPanel.getChart();
        final ChartRenderingInfo info = this.chartPanel.getChartRenderingInfo();

        // 1. (left) Y-Axis

        if (chart.getPlot() instanceof XYPlot) {
            final XYPlot vvp = (XYPlot) chart.getPlot();
            final ValueAxis primYAxis = vvp.getRangeAxis();
            if (primYAxis != null) {
                final double anchorValue =
                    primYAxis.java2DToValue(
                        (float) y, info.getPlotInfo().getDataArea(), vvp.getRangeAxisEdge()
                    );
                if (zoomFactor < 1.0) {
                    // zoom in
                    primYAxis.resizeRange(zoomFactor, anchorValue);

                } 
                else if (zoomFactor > 1.0) {
                    // zoom out
                    final Range range = new Range(this.primYMinMax[0], this.primYMinMax[1]);
                    adjustRange(primYAxis, range, zoomFactor, anchorValue);
                }
            }

            // 2. (right) Y-Axis

            if (chart.getPlot() instanceof XYPlot) {
                final XYPlot xyp = (XYPlot) chart.getPlot();
                final ValueAxis secYAxis = xyp.getRangeAxis(1);
                if (secYAxis != null) {
                    final double anchorValue =
                        secYAxis.java2DToValue(
                            (float) y,
                            info.getPlotInfo().getDataArea(),
                            xyp.getRangeAxisEdge(1));
                    if (zoomFactor < 1.0) {
                        // zoom in
                        secYAxis.resizeRange(zoomFactor, anchorValue);

                    } 
                    else if (zoomFactor > 1.0) {
                        // zoom out
                        final Range range = new Range(this.secondYMinMax[0], this.secondYMinMax[1]);
                        adjustRange(secYAxis, range, zoomFactor, anchorValue);
                    }
                }
            }
        }
    }

    /**
     * used for zooming
     * 
     * @param axis  the axis.
     * @param range  the range.
     * @param zoomFactor  the zoom factor.
     * @param anchorValue  the anchor value.
     */
    private void adjustRange(final ValueAxis axis, final Range range, final double zoomFactor, 
                             final double anchorValue) {

        if (axis == null || range == null) {
            return;
        }

        final double rangeMinVal = range.getLowerBound() 
                                   - range.getLength() * axis.getLowerMargin();
        final double rangeMaxVal = range.getUpperBound() 
                                   + range.getLength() * axis.getUpperMargin();
        final double halfLength = axis.getRange().getLength() * zoomFactor / 2;
        double zoomedMinVal = anchorValue - halfLength;
        double zoomedMaxVal = anchorValue + halfLength;
        double adjMinVal = zoomedMinVal;
        if (zoomedMinVal < rangeMinVal) {
            adjMinVal = rangeMinVal;
            zoomedMaxVal += rangeMinVal - zoomedMinVal;
        }
        double adjMaxVal = zoomedMaxVal;
        if (zoomedMaxVal > rangeMaxVal) {
            adjMaxVal = rangeMaxVal;
            zoomedMinVal -= zoomedMaxVal - rangeMaxVal;
            adjMinVal = Math.max(zoomedMinVal, rangeMinVal);
        }

        final Range adjusted = new Range(adjMinVal, adjMaxVal);
        axis.setRange(adjusted);
    }
    
}