levelrenderer.java

JFreeChart它主要是用来制作各种各样的图表

    /**
     * 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;
    }

    /**
     * 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).
     * @param pass  the pass index.
     */
    public void drawItem(Graphics2D g2, CategoryItemRendererState state,
            Rectangle2D dataArea, CategoryPlot plot, CategoryAxis domainAxis,
            ValueAxis rangeAxis, CategoryDataset dataset, int row, int column,
            int pass) {

        // 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);
        RectangleEdge edge = plot.getRangeAxisEdge();
        double barL = rangeAxis.valueToJava2D(value, dataArea, edge);

        // draw the bar...
        Line2D line = null;
        double x = 0.0;
        double y = 0.0;
        if (orientation == PlotOrientation.HORIZONTAL) {
            x = barL;
            y = barW0 + state.getBarWidth() / 2.0;
            line = new Line2D.Double(barL, barW0, barL,
                    barW0 + state.getBarWidth());
        }
        else {
            x = barW0 + state.getBarWidth() / 2.0;
            y = barL;
            line = new Line2D.Double(barW0, barL, barW0 + state.getBarWidth(),
                    barL);
        }
        Stroke itemStroke = getItemStroke(row, column);
        Paint itemPaint = getItemPaint(row, column);
        g2.setStroke(itemStroke);
        g2.setPaint(itemPaint);
        g2.draw(line);

        CategoryItemLabelGenerator generator = getItemLabelGenerator(row,
                column);
        if (generator != null && isItemLabelVisible(row, column)) {
            drawItemLabel(g2, orientation, dataset, row, column, x, y,
                    (value < 0.0));
        }

        // submit the current data point as a crosshair candidate
        int datasetIndex = plot.indexOf(dataset);
        updateCrosshairValues(state.getCrosshairState(),
                dataset.getRowKey(row), dataset.getColumnKey(column), value,
                datasetIndex, barW0, barL, orientation);

        // collect entity and tool tip information...
        EntityCollection entities = state.getEntityCollection();
        if (entities != null) {
            addItemEntity(entities, dataset, row, column, line.getBounds());
        }

    }

    /**
     * Calculates the available space for each series.
     *
     * @param space  the space along the entire axis (in Java2D units).
     * @param axis  the category axis.
     * @param categories  the number of categories.
     * @param series  the number of series.
     *
     * @return The width of one series.
     */
    protected double calculateSeriesWidth(double space, CategoryAxis axis,
                                          int categories, int series) {
        double factor = 1.0 - getItemMargin() - axis.getLowerMargin()
                        - axis.getUpperMargin();
        if (categories > 1) {
            factor = factor - axis.getCategoryMargin();
        }
        return (space * factor) / (categories * series);
    }

    /**
     * Returns the Java2D coordinate for the middle of the specified data item.
     *
     * @param rowKey  the row key.
     * @param columnKey  the column key.
     * @param dataset  the dataset.
     * @param axis  the axis.
     * @param area  the drawing area.
     * @param edge  the edge along which the axis lies.
     *
     * @return The Java2D coordinate.
     *
     * @since 1.0.11
     */
    public double getItemMiddle(Comparable rowKey, Comparable columnKey,
            CategoryDataset dataset, CategoryAxis axis, Rectangle2D area,
            RectangleEdge edge) {
        return axis.getCategorySeriesMiddle(columnKey, rowKey, dataset,
                this.itemMargin, area, edge);
    }

    /**
     * Tests an object for equality with this instance.
     *
     * @param obj  the object (<code>null</code> permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof LevelRenderer)) {
            return false;
        }
        LevelRenderer that = (LevelRenderer) obj;
        if (this.itemMargin != that.itemMargin) {
            return false;
        }
        if (this.maxItemWidth != that.maxItemWidth) {
            return false;
        }
        return super.equals(obj);
    }

    /**
     * Returns the maximum width, as a percentage of the available drawing
     * space.
     *
     * @return The maximum width.
     *
     * @deprecated Use {@link #getMaximumItemWidth()} instead.
     */
    public double getMaxItemWidth() {
        return this.maxItemWidth;
    }

    /**
     * Sets the maximum item width, which is specified as a percentage of the
     * available space for all items, and sends a {@link RendererChangeEvent}
     * to all registered listeners.
     *
     * @param percent  the percent.
     *
     * @deprecated Use {@link #setMaximumItemWidth(double)} instead.
     */
    public void setMaxItemWidth(double percent) {
        this.maxItemWidth = percent;
        fireChangeEvent();
    }

}