barrenderer.java

这是一个segy数据显示程序

        this.negativeItemLabelPositionFallback = position;
        notifyListeners(new RendererChangeEvent(this));
    }
    
    /**
     * Returns the lower clip value.
     * <P>
     * This value is recalculated in the initialise() method.
     *
     * @return The value.
     */
    public double getLowerClip() {
        return this.lowerClip;
    }

    /**
     * Returns the upper clip value.
     * <P>
     * This value is recalculated in the initialise() method.
     *
     * @return The value.
     */
    public double getUpperClip() {
        return this.upperClip;
    }

    /**
     * Initialises the renderer and returns a state object that will be passed to subsequent calls 
     * to the drawItem method.
     * <p>
     * This method gets called once at the start of the process of drawing a chart.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area in which the data is to be plotted.
     * @param plot  the plot.
     * @param rendererIndex  the renderer index.
     * @param info  collects chart rendering information for return to caller.
     * 
     * @return The renderer state.
     *
     */
    public CategoryItemRendererState initialise(Graphics2D g2,
                                                Rectangle2D dataArea,
                                                CategoryPlot plot,
                                                int rendererIndex,
                                                PlotRenderingInfo info) {

        CategoryItemRendererState state = super.initialise(g2, dataArea, plot, rendererIndex, info);

        // get the clipping values...
        ValueAxis rangeAxis = getRangeAxis(plot, rendererIndex);
        this.lowerClip = rangeAxis.getRange().getLowerBound();
        this.upperClip = rangeAxis.getRange().getUpperBound();

        // calculate the bar width
        calculateBarWidth(plot, dataArea, rendererIndex, state);

        return state;
        
    }
    
    /**
     * Calculates the bar width and stores it in the renderer state.
     * 
     * @param plot  the plot.
     * @param dataArea  the data area.
     * @param rendererIndex  the renderer index.
     * @param state  the renderer state.
     */
    protected void calculateBarWidth(CategoryPlot plot, 
                                     Rectangle2D dataArea, 
                                     int rendererIndex,
                                     CategoryItemRendererState state) {
                                         
        CategoryAxis domainAxis = getDomainAxis(plot, rendererIndex);
        CategoryDataset dataset = plot.getDataset(rendererIndex);
        if (dataset != null) {
            int columns = dataset.getColumnCount();
            int rows = dataset.getRowCount();
            double space = 0.0;
            PlotOrientation orientation = plot.getOrientation();
            if (orientation == PlotOrientation.HORIZONTAL) {
                space = dataArea.getHeight();
            }
            else if (orientation == PlotOrientation.VERTICAL) {
                space = dataArea.getWidth();
            }
            double maxWidth = space * getMaxBarWidth();
            double categoryMargin = 0.0;
            double currentItemMargin = 0.0;
            if (columns > 1) {
                categoryMargin = domainAxis.getCategoryMargin();
            }
            if (rows > 1) {
                currentItemMargin = getItemMargin();
            }
            double used = space * (1 - domainAxis.getLowerMargin() - domainAxis.getUpperMargin()
                                     - categoryMargin - currentItemMargin);
            if ((rows * columns) > 0) {
                state.setBarWidth(Math.min(used / (rows * columns), maxWidth));
            }
            else {
                state.setBarWidth(Math.min(used, maxWidth));
            }
        }
    }

    /**
     * Calculates the coordinate of the first "side" of a bar.  This will be the minimum 
     * x-coordinate for a vertical bar, and the minimum y-coordinate for a horizontal bar.
     * 
     * @param plot  the plot.
     * @param orientation  the plot orientation.
     * @param dataArea  the data area.
     * @param domainAxis  the domain axis.
     * @param state  the renderer state (has the bar width precalculated).
     * @param row  the row index.
     * @param column  the column index.
     * 
     * @return the coordinate.
     */
    protected double calculateBarW0(CategoryPlot plot, 
                                    PlotOrientation orientation, 
                                    Rectangle2D dataArea,
                                    CategoryAxis domainAxis,
                                    CategoryItemRendererState state,
                                    int row,
                                    int column) {
        // calculate bar width...
        double space = 0.0;
        if (orientation == PlotOrientation.HORIZONTAL) {
            space = dataArea.getHeight();
        }
        else {
            space = dataArea.getWidth();
        }
        double barW0 = domainAxis.getCategoryStart(
            column, getColumnCount(), dataArea, plot.getDomainAxisEdge()
        );
        int seriesCount = getRowCount();
        int categoryCount = getColumnCount();
        if (seriesCount > 1) {
            double seriesGap = space * getItemMargin() / (categoryCount * (seriesCount - 1));
            double seriesW = calculateSeriesWidth(space, domainAxis, categoryCount, seriesCount);
            barW0 = barW0 + row * (seriesW + seriesGap) 
                          + (seriesW / 2.0) - (state.getBarWidth() / 2.0);
        }
        else {
            barW0 = domainAxis.getCategoryMiddle(
                column, getColumnCount(), dataArea, plot.getDomainAxisEdge()
            ) - state.getBarWidth() / 2.0;
        }
        return barW0;
    }
    
    /**
     * Calculates the coordinates for the length of a single bar.
     * 
     * @param value  the value represented by the bar.
     * 
     * @return the coordinates for each end of the bar (or <code>null</code> if the bar is not
     *         visible for the current axis range).
     */
    protected double[] calculateBarL0L1(double value) {

        double base = 0.0;
        double lclip = getLowerClip();
        double uclip = getUpperClip();
        if (uclip <= 0.0) {  // cases 1, 2, 3 and 4
            if (value >= uclip) {
                return null; // bar is not visible
            }
            base = uclip;
            if (value <= lclip) {
                value = lclip;
            }
        }
        else if (lclip <= 0.0) { // cases 5, 6, 7 and 8
            if (value >= uclip) {
                value = uclip;
            }
            else {
                if (value <= lclip) {
                    value = lclip;
                }
            }
        }
        else { // cases 9, 10, 11 and 12
            if (value <= lclip) {
                return null; // bar is not visible
            }
            base = lclip;
            if (value >= uclip) {
                value = uclip;
            }
        }
        return new double[] {base, value};
    }

    /**
     * Draws the bar for a single (series, category) data item.
     *
     * @param g2  the graphics device.
     * @param state  the renderer state.
     * @param dataArea  the data area.
     * @param plot  the plot.
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the range axis.
     * @param dataset  the dataset.
     * @param row  the row index (zero-based).
     * @param column  the column index (zero-based).
     */
    public void drawItem(Graphics2D g2,
                         CategoryItemRendererState state,
                         Rectangle2D dataArea,
                         CategoryPlot plot,
                         CategoryAxis domainAxis,
                         ValueAxis rangeAxis,
                         CategoryDataset dataset,
                         int row,
                         int column) {

        // nothing is drawn for null values...
        Number dataValue = dataset.getValue(row, column);
        if (dataValue == null) {
            return;
        }
        
        double value = dataValue.doubleValue();
        
        PlotOrientation orientation = plot.getOrientation();
        double barW0 = calculateBarW0(plot, orientation, dataArea, domainAxis, state, row, column);
        double[] barL0L1 = calculateBarL0L1(value);
        if (barL0L1 == null) {
            return;  // the bar is not visible
        }
        
        RectangleEdge edge = plot.getRangeAxisEdge();
        double transL0 = rangeAxis.valueToJava2D(barL0L1[0], dataArea, edge);
        double transL1 = rangeAxis.valueToJava2D(barL0L1[1], dataArea, edge);
        double barL0 = Math.min(transL0, transL1);
        double barLength = Math.max(Math.abs(transL1 - transL0), getMinimumBarLength());

        // draw the bar...
        Rectangle2D bar = null;
        if (orientation == PlotOrientation.HORIZONTAL) {
            bar = new Rectangle2D.Double(barL0, barW0, barLength, state.getBarWidth());
        }
        else {
            bar = new Rectangle2D.Double(barW0, barL0, state.getBarWidth(), barLength);
        }
        Paint itemPaint = getItemPaint(row, column);
        if (getGradientPaintTransformer() != null && itemPaint instanceof GradientPaint) {
            GradientPaint gp = (GradientPaint) itemPaint;
            itemPaint = getGradientPaintTransformer().transform(gp, bar);
        }
        g2.setPaint(itemPaint);
        g2.fill(bar);

        // draw the outline...
        if (isDrawBarOutline() && state.getBarWidth() > BAR_OUTLINE_WIDTH_THRESHOLD) {
            Stroke stroke = getItemOutlineStroke(row, column);
            Paint paint = getItemOutlinePaint(row, column);
            if (stroke != null && paint != null) {
                g2.setStroke(stroke);
                g2.setPaint(paint);
                g2.draw(bar);
            }
        }

        CategoryLabelGenerator generator = getLabelGenerator(row, column);
        if (generator != null && isItemLabelVisible(row, column)) {
            drawItemLabel(g2, dataset, row, column, plot, generator, bar, (value < 0.0));
        }        
                
        // collect entity and tool tip information...
        if (state.getInfo() != null) {
            EntityCollection entities = state.getInfo().getOwner().getEntityCollection();
            if (entities != null) {
                String tip = null;
                CategoryToolTipGenerator tipster = getToolTipGenerator(row, column);
                if (tipster != null) {
                    tip = tipster.generateToolTip(dataset, row, column);
                }
                String url = null;
                if (getItemURLGenerator(row, column) != null) {
                    url = getItemURLGenerator(row, column).generateURL(dataset, row, column);