xyarearenderer2.java

制作图表的好工具

                }
                String urlText = null;
                if (getLegendItemURLGenerator() != null) {
                    urlText = getLegendItemURLGenerator().generateLabel(
                        dataset, series
                    );
                }
                Paint paint = getSeriesPaint(series);
                result = new LegendItem(label, description, toolTipText, 
                        urlText, this.legendArea, paint);
            }
        }
        return result;
    }
    
    /**
     * Draws the visual representation of a single data item.
     *
     * @param g2  the graphics device.
     * @param state  the renderer state.
     * @param dataArea  the area within which the data is being drawn.
     * @param info  collects information about the drawing.
     * @param plot  the plot (can be used to obtain standard color 
     *              information etc).
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the range axis.
     * @param dataset  the dataset.
     * @param series  the series index (zero-based).
     * @param item  the item index (zero-based).
     * @param crosshairState  crosshair information for the plot 
     *                        (<code>null</code> permitted).
     * @param pass  the pass index.
     */
    public void drawItem(Graphics2D g2,
                         XYItemRendererState state,
                         Rectangle2D dataArea,
                         PlotRenderingInfo info,
                         XYPlot plot,
                         ValueAxis domainAxis,
                         ValueAxis rangeAxis,
                         XYDataset dataset,
                         int series,
                         int item,
                         CrosshairState crosshairState,
                         int pass) {
        
        if (!getItemVisible(series, item)) {
            return;   
        }
        // get the data point...
        double x1 = dataset.getXValue(series, item);
        double y1 = dataset.getYValue(series, item);
        if (Double.isNaN(y1)) {
            y1 = 0.0;
        }
        
        double transX1 = domainAxis.valueToJava2D(
            x1, dataArea, plot.getDomainAxisEdge()
        );
        double transY1 = rangeAxis.valueToJava2D(
            y1, dataArea, plot.getRangeAxisEdge()
        );
        
        // get the previous point and the next point so we can calculate a 
        // "hot spot" for the area (used by the chart entity)...
        double x0 = dataset.getXValue(series, Math.max(item - 1, 0));
        double y0 = dataset.getYValue(series, Math.max(item - 1, 0));
        if (Double.isNaN(y0)) {
            y0 = 0.0;
        }
        double transX0 = domainAxis.valueToJava2D(
            x0, dataArea, plot.getDomainAxisEdge()
        );
        double transY0 = rangeAxis.valueToJava2D(
            y0, dataArea, plot.getRangeAxisEdge()
        );
        
        int itemCount = dataset.getItemCount(series);
        double x2 = dataset.getXValue(
            series, Math.min(item + 1, itemCount - 1)
        );
        double y2 = dataset.getYValue(
            series, Math.min(item + 1, itemCount - 1)
        );
        if (Double.isNaN(y2)) {
            y2 = 0.0;
        }
        double transX2 = domainAxis.valueToJava2D(
            x2, dataArea, plot.getDomainAxisEdge()
        );
        double transY2 = rangeAxis.valueToJava2D(
            y2, dataArea, plot.getRangeAxisEdge()
        );
        
        double transZero = rangeAxis.valueToJava2D(
            0.0, dataArea, plot.getRangeAxisEdge()
        );
        Polygon hotspot = null;
        if (plot.getOrientation() == PlotOrientation.HORIZONTAL) {
            hotspot = new Polygon();
            hotspot.addPoint(
                (int) transZero, (int) ((transX0 + transX1) / 2.0)
            );
            hotspot.addPoint(
                (int) ((transY0 + transY1) / 2.0), 
                (int) ((transX0 + transX1) / 2.0)
            );
            hotspot.addPoint((int) transY1, (int) transX1);
            hotspot.addPoint(
                (int) ((transY1 + transY2) / 2.0), 
                (int) ((transX1 + transX2) / 2.0)
            );
            hotspot.addPoint(
                (int) transZero, (int) ((transX1 + transX2) / 2.0)
            );
        }
        else {  // vertical orientation
            hotspot = new Polygon();
            hotspot.addPoint(
                (int) ((transX0 + transX1) / 2.0), (int) transZero
            );
            hotspot.addPoint(
                (int) ((transX0 + transX1) / 2.0), 
                (int) ((transY0 + transY1) / 2.0)
            );
            hotspot.addPoint((int) transX1, (int) transY1);
            hotspot.addPoint(
                (int) ((transX1 + transX2) / 2.0), 
                (int) ((transY1 + transY2) / 2.0)
            );
            hotspot.addPoint(
                (int) ((transX1 + transX2) / 2.0), (int) transZero
            );
        }
                
        PlotOrientation orientation = plot.getOrientation();
        Paint paint = getItemPaint(series, item);
        Stroke stroke = getItemStroke(series, item);
        g2.setPaint(paint);
        g2.setStroke(stroke);

        if (getPlotLines()) {
            if (item > 0) {
                if (plot.getOrientation() == PlotOrientation.VERTICAL) {
                    state.workingLine.setLine(
                        transX0, transY0, transX1, transY1
                    );
                }
                else if (plot.getOrientation() == PlotOrientation.HORIZONTAL) {
                    state.workingLine.setLine(
                        transY0, transX0, transY1, transX1
                    );
                }
                g2.draw(state.workingLine);
            }
        }

        // Check if the item is the last item for the series.
        // and number of items > 0.  We can't draw an area for a single point.
        g2.fill(hotspot);

        // draw an outline around the Area.
        if (isOutline()) {
            g2.setStroke(getSeriesOutlineStroke(series));
            g2.setPaint(getSeriesOutlinePaint(series));
            g2.draw(hotspot);
        }
        updateCrosshairValues(
            crosshairState, x1, y1, transX1, transY1, orientation
        );
        
        // collect entity and tool tip information...
        if (state.getInfo() != null) {
            EntityCollection entities = state.getEntityCollection();
            if (entities != null && hotspot != null) {
                String tip = null;
                XYToolTipGenerator generator = getToolTipGenerator(
                    series, item
                );
                if (generator != null) {
                    tip = generator.generateToolTip(dataset, series, item);
                }
                String url = null;
                if (getURLGenerator() != null) {
                    url = getURLGenerator().generateURL(dataset, series, item);
                }
                XYItemEntity entity = new XYItemEntity(
                    hotspot, dataset, series, item, tip, url
                );
                entities.add(entity);
            }
        }

    }

    /**
     * Returns a clone of the renderer.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException  if the renderer cannot be cloned.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
    
    /**
     * Provides serialization support.
     *
     * @param stream  the input stream.
     *
     * @throws IOException  if there is an I/O error.
     * @throws ClassNotFoundException  if there is a classpath problem.
     */
    private void readObject(ObjectInputStream stream) 
            throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        this.legendArea = SerialUtilities.readShape(stream);
    }
    
    /**
     * Provides serialization support.
     *
     * @param stream  the output stream.
     *
     * @throws IOException  if there is an I/O error.
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
        SerialUtilities.writeShape(this.legendArea, stream);
    }

}