# GroupedStackedBarRenderer.java

    /* ===========================================================
     * JFreeChart : a free chart library for the Java(tm) platform
     * ===========================================================
     *
     * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
     *
     * Project Info:  http://www.jfree.org/jfreechart/index.html
     *
     * This library is free software; you can redistribute it and/or modify it
     * under the terms of the GNU Lesser General Public License as published by
     * the Free Software Foundation; either version 2.1 of the License, or
     * (at your option) any later version.
     *
     * This library is distributed in the hope that it will be useful, but
     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
     * License for more details.
     *
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
     * USA.
     *
     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
     * in the United States and other countries.]
     *
     * ------------------------------
     * GroupedStackedBarRenderer.java
     * ------------------------------
     * (C) Copyright 2004-2008, by Object Refinery Limited and Contributors.
     *
     * Original Author:  David Gilbert (for Object Refinery Limited);
     * Contributor(s):   -;
     *
     * Changes
     * -------
     * 29-Apr-2004 : Version 1 (DG);
     * 08-Jul-2004 : Added equals() method (DG);
     * 05-Nov-2004 : Modified drawItem() signature (DG);
     * 07-Jan-2005 : Renamed getRangeExtent() --> findRangeBounds (DG);
     * 20-Apr-2005 : Renamed CategoryLabelGenerator
     *               --> CategoryItemLabelGenerator (DG);
     * 22-Sep-2005 : Renamed getMaxBarWidth() --> getMaximumBarWidth() (DG);
     * 20-Dec-2007 : Fix for bug 1848961 (DG);
     *
     */

    package org.jfree.chart.renderer.category;

    import java.awt.GradientPaint;
    import java.awt.Graphics2D;
    import java.awt.Paint;
    import java.awt.geom.Rectangle2D;
    import java.io.Serializable;

    import org.jfree.chart.axis.CategoryAxis;
    import org.jfree.chart.axis.ValueAxis;
    import org.jfree.chart.entity.EntityCollection;
    import org.jfree.chart.event.RendererChangeEvent;
    import org.jfree.chart.labels.CategoryItemLabelGenerator;
    import org.jfree.chart.plot.CategoryPlot;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.data.KeyToGroupMap;
    import org.jfree.data.Range;
    import org.jfree.data.category.CategoryDataset;
    import org.jfree.data.general.DatasetUtilities;
    import org.jfree.ui.RectangleEdge;
    import org.jfree.util.PublicCloneable;

    /**
     * A renderer that draws stacked bars within groups.  This will probably be
     * merged with the {@link StackedBarRenderer} class at some point.
     */
    public class GroupedStackedBarRenderer extends StackedBarRenderer
            implements Cloneable, PublicCloneable, Serializable {

        /** For serialization. */
        private static final long serialVersionUID = -2725921399005922939L;

        /** A map used to assign each series to a group. */
        private KeyToGroupMap seriesToGroupMap;

        /**
         * Creates a new renderer.
         */
        public GroupedStackedBarRenderer() {
            super();
            this.seriesToGroupMap = new KeyToGroupMap();
        }

        /**
         * Updates the map used to assign each series to a group, and sends a
         * {@link RendererChangeEvent} to all registered listeners.
         *
         * @param map  the map (<code>null</code> not permitted).
         */
        public void setSeriesToGroupMap(KeyToGroupMap map) {
            if (map == null) {
                throw new IllegalArgumentException("Null 'map' argument.");
            }
            this.seriesToGroupMap = map;
            fireChangeEvent();
        }

        /**
         * Returns the range of values the renderer requires to display all the
         * items from the specified dataset.
         *
         * @param dataset  the dataset (<code>null</code> permitted).
         *
         * @return The range (or <code>null</code> if the dataset is
         *         <code>null</code> or empty).
         */
        public Range findRangeBounds(CategoryDataset dataset) {
            Range r = DatasetUtilities.findStackedRangeBounds(
                    dataset, this.seriesToGroupMap);
            return r;
        }

        /**
         * Calculates the bar width and stores it in the renderer state.  We
         * override the method in the base class to take account of the
         * series-to-group mapping.
         *
         * @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) {

            // calculate the bar width
            CategoryAxis xAxis = plot.getDomainAxisForDataset(rendererIndex);
            CategoryDataset data = plot.getDataset(rendererIndex);
            if (data != null) {
                PlotOrientation orientation = plot.getOrientation();
                double space = 0.0;
                if (orientation == PlotOrientation.HORIZONTAL) {
                    space = dataArea.getHeight();
                }
                else if (orientation == PlotOrientation.VERTICAL) {
                    space = dataArea.getWidth();
                }
                double maxWidth = space * getMaximumBarWidth();
                int groups = this.seriesToGroupMap.getGroupCount();
                int categories = data.getColumnCount();
                int columns = groups * categories;
                double categoryMargin = 0.0;
                double itemMargin = 0.0;
                if (categories > 1) {
                    categoryMargin = xAxis.getCategoryMargin();
                }
                if (groups > 1) {
                    itemMargin = getItemMargin();
                }

                double used = space * (1 - xAxis.getLowerMargin()
                                         - xAxis.getUpperMargin()
                                         - categoryMargin - itemMargin);
                if (columns > 0) {
                    state.setBarWidth(Math.min(used / 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 groupCount = this.seriesToGroupMap.getGroupCount();
            int groupIndex = this.seriesToGroupMap.getGroupIndex(
                    this.seriesToGroupMap.getGroup(plot.getDataset(
                            plot.getIndexOf(this)).getRowKey(row)));
            int categoryCount = getColumnCount();
            if (groupCount > 1) {
                double groupGap = space * getItemMargin()
                                  / (categoryCount * (groupCount - 1));
                double groupW = calculateSeriesWidth(space, domainAxis,
                        categoryCount, groupCount);
                barW0 = barW0 + groupIndex * (groupW + groupGap)
                              + (groupW / 2.0) - (state.getBarWidth() / 2.0);
            }
            else {
                barW0 = domainAxis.getCategoryMiddle(column, getColumnCount(),
                        dataArea, plot.getDomainAxisEdge())
                        - state.getBarWidth() / 2.0;
            }
            return barW0;
        }

        /**
         * Draws a stacked bar for a specific item.
         *
         * @param g2  the graphics device.
         * @param state  the renderer state.
         * @param dataArea  the plot area.
         * @param plot  the plot.
         * @param domainAxis  the domain (category) axis.
         * @param rangeAxis  the range (value) axis.
         * @param dataset  the data.
         * @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();
            Comparable group = this.seriesToGroupMap.getGroup(
                    dataset.getRowKey(row));
            PlotOrientation orientation = plot.getOrientation();
            double barW0 = calculateBarW0(plot, orientation, dataArea, domainAxis,
                    state, row, column);

            double positiveBase = 0.0;
            double negativeBase = 0.0;

            for (int i = 0; i < row; i++) {
                if (group.equals(this.seriesToGroupMap.getGroup(
                        dataset.getRowKey(i)))) {
                    Number v = dataset.getValue(i, column);
                    if (v != null) {
                        double d = v.doubleValue();
                        if (d > 0) {
                            positiveBase = positiveBase + d;
                        }
                        else {
                            negativeBase = negativeBase + d;
                        }
                    }
                }
            }

            double translatedBase;
            double translatedValue;
            RectangleEdge location = plot.getRangeAxisEdge();
            if (value > 0.0) {
                translatedBase = rangeAxis.valueToJava2D(positiveBase, dataArea,
                        location);
                translatedValue = rangeAxis.valueToJava2D(positiveBase + value,
                        dataArea, location);
            }
            else {
                translatedBase = rangeAxis.valueToJava2D(negativeBase, dataArea,
                        location);
                translatedValue = rangeAxis.valueToJava2D(negativeBase + value,
                        dataArea, location);
            }
            double barL0 = Math.min(translatedBase, translatedValue);
            double barLength = Math.max(Math.abs(translatedValue - translatedBase),
                    getMinimumBarLength());

            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);
            if (isDrawBarOutline()
                    && state.getBarWidth() > BAR_OUTLINE_WIDTH_THRESHOLD) {
                g2.setStroke(getItemStroke(row, column));
                g2.setPaint(getItemOutlinePaint(row, column));
                g2.draw(bar);
            }

            CategoryItemLabelGenerator generator = getItemLabelGenerator(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.getEntityCollection();
                if (entities != null) {
                    addItemEntity(entities, dataset, row, column, bar);
                }
            }

        }

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

    }