# StackedBarRenderer.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.]
     *
     * -----------------------
     * StackedBarRenderer.java
     * -----------------------
     * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
     *
     * Original Author:  David Gilbert (for Object Refinery Limited);
     * Contributor(s):   Richard Atkinson;
     *                   Thierry Saura;
     *                   Christian W. Zuckschwerdt;
     *
     * Changes
     * -------
     * 19-Oct-2001 : Version 1 (DG);
     * 22-Oct-2001 : Renamed DataSource.java --> Dataset.java etc. (DG);
     * 23-Oct-2001 : Changed intro and trail gaps on bar plots to use percentage of
     *               available space rather than a fixed number of units (DG);
     * 15-Nov-2001 : Modified to allow for null data values (DG);
     * 22-Nov-2001 : Modified to allow for negative data values (DG);
     * 13-Dec-2001 : Added tooltips (DG);
     * 16-Jan-2002 : Fixed bug for single category datasets (DG);
     * 15-Feb-2002 : Added isStacked() method (DG);
     * 14-Mar-2002 : Modified to implement the CategoryItemRenderer interface (DG);
     * 24-May-2002 : Incorporated tooltips into chart entities (DG);
     * 11-Jun-2002 : Added check for (permitted) null info object, bug and fix
     *               reported by David Basten.  Also updated Javadocs. (DG);
     * 25-Jun-2002 : Removed redundant import (DG);
     * 26-Jun-2002 : Small change to entity (DG);
     * 05-Aug-2002 : Small modification to drawCategoryItem method to support URLs
     *               for HTML image maps (RA);
     * 08-Aug-2002 : Added optional linking lines, contributed by Thierry
     *               Saura (DG);
     * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
     * 24-Oct-2002 : Amendments for changes in CategoryDataset interface and
     *               CategoryToolTipGenerator interface (DG);
     * 05-Nov-2002 : Replaced references to CategoryDataset with TableDataset (DG);
     * 26-Nov-2002 : Replaced isStacked() method with getRangeType() method (DG);
     * 17-Jan-2003 : Moved plot classes to a separate package (DG);
     * 25-Mar-2003 : Implemented Serializable (DG);
     * 12-May-2003 : Merged horizontal and vertical stacked bar renderers (DG);
     * 30-Jul-2003 : Modified entity constructor (CZ);
     * 08-Sep-2003 : Fixed bug 799668 (isBarOutlineDrawn() ignored) (DG);
     * 16-Sep-2003 : Changed ChartRenderingInfo --> PlotRenderingInfo (DG);
     * 21-Oct-2003 : Moved bar width into renderer state (DG);
     * 26-Nov-2003 : Added code to respect maxBarWidth attribute (DG);
     * 05-Nov-2004 : Changed to a two-pass renderer so that item labels are not
     *               overwritten by other bars (DG);
     * 07-Jan-2005 : Renamed getRangeExtent() --> findRangeBounds() (DG);
     * 29-Mar-2005 : Modified drawItem() method so that a zero value is handled
     *               within the code for positive rather than negative values (DG);
     * 20-Apr-2005 : Renamed CategoryLabelGenerator
     *               --> CategoryItemLabelGenerator (DG);
     * 17-May-2005 : Added flag to allow rendering values as percentages - inspired
     *               by patch 1200886 submitted by John Xiao (DG);
     * 09-Jun-2005 : Added accessor methods for the renderAsPercentages flag,
     *               provided equals() method, and use addItemEntity from
     *               superclass (DG);
     * 09-Jun-2005 : Added support for GradientPaint - see bug report 1215670 (DG);
     * 22-Sep-2005 : Renamed getMaxBarWidth() --> getMaximumBarWidth() (DG);
     * 29-Sep-2005 : Use outline stroke in drawItem method - see bug report
     *               1304139 (DG);
     * ------------- JFREECHART 1.0.x ---------------------------------------------
     * 11-Oct-2006 : Source reformatting (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.labels.ItemLabelAnchor;
    import org.jfree.chart.labels.ItemLabelPosition;
    import org.jfree.chart.plot.CategoryPlot;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.data.DataUtilities;
    import org.jfree.data.Range;
    import org.jfree.data.category.CategoryDataset;
    import org.jfree.data.general.DatasetUtilities;
    import org.jfree.ui.GradientPaintTransformer;
    import org.jfree.ui.RectangleEdge;
    import org.jfree.ui.TextAnchor;
    import org.jfree.util.PublicCloneable;

    /**
     * A stacked bar renderer for use with the
     * {@link org.jfree.chart.plot.CategoryPlot} class.
     */
    public class StackedBarRenderer extends BarRenderer
            implements Cloneable, PublicCloneable, Serializable {

        /** For serialization. */
        static final long serialVersionUID = 6402943811500067531L;

        /** A flag that controls whether the bars display values or percentages. */
        private boolean renderAsPercentages;

        /**
         * Creates a new renderer.  By default, the renderer has no tool tip
         * generator and no URL generator.  These defaults have been chosen to
         * minimise the processing required to generate a default chart.  If you
         * require tool tips or URLs, then you can easily add the required
         * generators.
         */
        public StackedBarRenderer() {
            this(false);
        }

        /**
         * Creates a new renderer.
         *
         * @param renderAsPercentages  a flag that controls whether the data values
         *                             are rendered as percentages.
         */
        public StackedBarRenderer(boolean renderAsPercentages) {
            super();
            this.renderAsPercentages = renderAsPercentages;

            // set the default item label positions, which will only be used if
            // the user requests visible item labels...
            ItemLabelPosition p = new ItemLabelPosition(ItemLabelAnchor.CENTER,
                    TextAnchor.CENTER);
            setBasePositiveItemLabelPosition(p);
            setBaseNegativeItemLabelPosition(p);
            setPositiveItemLabelPositionFallback(null);
            setNegativeItemLabelPositionFallback(null);
        }

        /**
         * Returns <code>true</code> if the renderer displays each item value as
         * a percentage (so that the stacked bars add to 100%), and
         * <code>false</code> otherwise.
         *
         * @return A boolean.
         *
         * @see #setRenderAsPercentages(boolean)
         */
        public boolean getRenderAsPercentages() {
            return this.renderAsPercentages;
        }

        /**
         * Sets the flag that controls whether the renderer displays each item
         * value as a percentage (so that the stacked bars add to 100%), and sends
         * a {@link RendererChangeEvent} to all registered listeners.
         *
         * @param asPercentages  the flag.
         *
         * @see #getRenderAsPercentages()
         */
        public void setRenderAsPercentages(boolean asPercentages) {
            this.renderAsPercentages = asPercentages;
            fireChangeEvent();
        }

        /**
         * Returns the number of passes (<code>2</code>) required by this renderer.
         * The first pass is used to draw the bars, the second pass is used to
         * draw the item labels (if visible).
         *
         * @return The number of passes required by the renderer.
         */
        public int getPassCount() {
            return 2;
        }

        /**
         * 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 empty).
         */
        public Range findRangeBounds(CategoryDataset dataset) {
            if (this.renderAsPercentages) {
                return new Range(0.0, 1.0);
            }
            else {
                return DatasetUtilities.findStackedRangeBounds(dataset, getBase());
            }
        }

        /**
         * 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) {

            // 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 columns = data.getColumnCount();
                double categoryMargin = 0.0;
                if (columns > 1) {
                    categoryMargin = xAxis.getCategoryMargin();
                }

                double used = space * (1 - xAxis.getLowerMargin()
                                         - xAxis.getUpperMargin()
                                         - categoryMargin);
                if (columns > 0) {
                    state.setBarWidth(Math.min(used / columns, maxWidth));
                }
                else {
                    state.setBarWidth(Math.min(used, maxWidth));
                }
            }

        }

        /**
         * 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();
            double total = 0.0;  // only needed if calculating percentages
            if (this.renderAsPercentages) {
                total = DataUtilities.calculateColumnTotal(dataset, column);
                value = value / total;
            }

            PlotOrientation orientation = plot.getOrientation();
            double barW0 = domainAxis.getCategoryMiddle(column, getColumnCount(),
                    dataArea, plot.getDomainAxisEdge())
                    - state.getBarWidth() / 2.0;

            double positiveBase = getBase();
            double negativeBase = positiveBase;

            for (int i = 0; i < row; i++) {
                Number v = dataset.getValue(i, column);
                if (v != null) {
                    double d = v.doubleValue();
                    if (this.renderAsPercentages) {
                        d = d / total;
                    }
                    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);
            }
            if (pass == 0) {
                Paint itemPaint = getItemPaint(row, column);
                GradientPaintTransformer t = getGradientPaintTransformer();
                if (t != null && itemPaint instanceof GradientPaint) {
                    itemPaint = t.transform((GradientPaint) itemPaint, bar);
                }
                g2.setPaint(itemPaint);
                g2.fill(bar);
                if (isDrawBarOutline()
                        && state.getBarWidth() > BAR_OUTLINE_WIDTH_THRESHOLD) {
                    g2.setStroke(getItemOutlineStroke(row, column));
                    g2.setPaint(getItemOutlinePaint(row, column));
                    g2.draw(bar);
                }

                // add an item entity, if this information is being collected
                EntityCollection entities = state.getEntityCollection();
                if (entities != null) {
                    addItemEntity(entities, dataset, row, column, bar);
                }
            }
            else if (pass == 1) {
                CategoryItemLabelGenerator generator = getItemLabelGenerator(row,
                        column);
                if (generator != null && isItemLabelVisible(row, column)) {
                    drawItemLabel(g2, dataset, row, column, plot, generator, bar,
                            (value < 0.0));
                }
            }
        }

        /**
         * 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 StackedBarRenderer)) {
                return false;
            }
            StackedBarRenderer that = (StackedBarRenderer) obj;
            if (this.renderAsPercentages != that.renderAsPercentages) {
                return false;
            }
            return super.equals(obj);
        }

    }