# ClusteredXYBarRenderer.java

    /* ===========================================================
     * JFreeChart : a free chart library for the Java(tm) platform
     * ===========================================================
     *
     * (C) Copyright 2000-2007, 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.]
     *
     * ---------------------------
     * ClusteredXYBarRenderer.java
     * ---------------------------
     * (C) Copyright 2003-2007, by Paolo Cova and Contributors.
     *
     * Original Author:  Paolo Cova;
     * Contributor(s):   David Gilbert (for Object Refinery Limited);
     *                   Christian W. Zuckschwerdt;
     *                   Matthias Rose;
     *
     * Changes
     * -------
     * 24-Jan-2003 : Version 1, contributed by Paolo Cova (DG);
     * 25-Mar-2003 : Implemented Serializable (DG);
     * 01-May-2003 : Modified drawItem() method signature (DG);
     * 30-Jul-2003 : Modified entity constructor (CZ);
     * 20-Aug-2003 : Implemented Cloneable and PublicCloneable (DG);
     * 16-Sep-2003 : Changed ChartRenderingInfo --> PlotRenderingInfo (DG);
     * 07-Oct-2003 : Added renderer state (DG);
     * 03-Nov-2003 : In draw method added state parameter and y==null value
     *               handling (MR);
     * 25-Feb-2004 : Replaced CrosshairInfo with CrosshairState (DG);
     * 15-Jul-2004 : Switched getX() with getXValue() and getY() with
     *               getYValue() (DG);
     * 01-Oct-2004 : Fixed bug where 'drawBarOutline' flag is ignored (DG);
     * 16-May-2005 : Fixed to used outline stroke for bar outlines.  Removed some
     *               redundant code with the result that the renderer now respects
     *               the 'base' setting from the super-class. Added an equals()
     *               method (DG);
     * 19-May-2005 : Added minimal item label implementation - needs improving (DG);
     * ------------- JFREECHART 1.0.x ---------------------------------------------
     * 11-Dec-2006 : Added support for GradientPaint (DG);
     * 12-Jun-2007 : Added override to findDomainBounds() to handle cluster offset,
     *               fixed rendering to handle inverted axes, and simplified
     *               entity generation code (DG);
     *
     */

    package org.jfree.chart.renderer.xy;

    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.ValueAxis;
    import org.jfree.chart.entity.EntityCollection;
    import org.jfree.chart.labels.XYItemLabelGenerator;
    import org.jfree.chart.plot.CrosshairState;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.chart.plot.PlotRenderingInfo;
    import org.jfree.chart.plot.XYPlot;
    import org.jfree.data.Range;
    import org.jfree.data.xy.IntervalXYDataset;
    import org.jfree.data.xy.XYDataset;
    import org.jfree.ui.RectangleEdge;
    import org.jfree.util.PublicCloneable;

    /**
     * An extension of {@link XYBarRenderer} that displays bars for different
     * series values at the same x next to each other. The assumption here is
     * that for each x (time or else) there is a y value for each series. If
     * this is not the case, there will be spaces between bars for a given x.
     * <P>
     * This renderer does not include code to calculate the crosshair point for the
     * plot.
     */
    public class ClusteredXYBarRenderer extends XYBarRenderer
            implements Cloneable, PublicCloneable, Serializable {

        /** For serialization. */
        private static final long serialVersionUID = 5864462149177133147L;

        /** Determines whether bar center should be interval start. */
        private boolean centerBarAtStartValue;

        /**
         * Default constructor. Bar margin is set to 0.0.
         */
        public ClusteredXYBarRenderer() {
            this(0.0, false);
        }

        /**
         * Constructs a new XY clustered bar renderer.
         *
         * @param margin  the percentage amount to trim from the width of each bar.
         * @param centerBarAtStartValue  if true, bars will be centered on the
         *         start of the time period.
         */
        public ClusteredXYBarRenderer(double margin,
                                      boolean centerBarAtStartValue) {
            super(margin);
            this.centerBarAtStartValue = centerBarAtStartValue;
        }

        /**
         * Returns the x-value bounds for the specified dataset.
         *
         * @param dataset  the dataset (<code>null</code> permitted).
         *
         * @return The bounds (possibly <code>null</code>).
         */
        public Range findDomainBounds(XYDataset dataset) {
            if (dataset == null) {
                return null;
            }
            // need to handle cluster centering as a special case
            if (this.centerBarAtStartValue) {
                return findDomainBoundsWithOffset((IntervalXYDataset) dataset);
            }
            else {
                return super.findDomainBounds(dataset);
            }
        }

        /**
         * Iterates over the items in an {@link IntervalXYDataset} to find
         * the range of x-values including the interval OFFSET so that it centers
         * the interval around the start value.
         *
         * @param dataset  the dataset (<code>null</code> not permitted).
         *
         * @return The range (possibly <code>null</code>).
         */
        protected Range findDomainBoundsWithOffset(IntervalXYDataset dataset) {
            if (dataset == null) {
                throw new IllegalArgumentException("Null 'dataset' argument.");
            }
            double minimum = Double.POSITIVE_INFINITY;
            double maximum = Double.NEGATIVE_INFINITY;
            int seriesCount = dataset.getSeriesCount();
            double lvalue;
            double uvalue;
            for (int series = 0; series < seriesCount; series++) {
                int itemCount = dataset.getItemCount(series);
                for (int item = 0; item < itemCount; item++) {
                    lvalue = dataset.getStartXValue(series, item);
                    uvalue = dataset.getEndXValue(series, item);
                    double offset = (uvalue - lvalue) / 2.0;
                    lvalue = lvalue - offset;
                    uvalue = uvalue - offset;
                    minimum = Math.min(minimum, lvalue);
                    maximum = Math.max(maximum, uvalue);
                }
            }

            if (minimum > maximum) {
                return null;
            }
            else {
                return new Range(minimum, maximum);
            }
        }

        /**
         * Draws the visual representation of a single data item. This method
         * is mostly copied from the superclass, the change is that in the
         * calculated space for a singe bar we draw bars for each series next to
         * each other. The width of each bar is the available width divided by
         * the number of series. Bars for each series are drawn in order left to
         * right.
         *
         * @param g2  the graphics device.
         * @param state  the renderer state.
         * @param dataArea  the area within which the plot 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.
         * @param item  the item index.
         * @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) {

            IntervalXYDataset intervalDataset = (IntervalXYDataset) dataset;

            double y0;
            double y1;
            if (getUseYInterval()) {
                y0 = intervalDataset.getStartYValue(series, item);
                y1 = intervalDataset.getEndYValue(series, item);
            }
            else {
                y0 = getBase();
                y1 = intervalDataset.getYValue(series, item);
            }
            if (Double.isNaN(y0) || Double.isNaN(y1)) {
                return;
            }

            double yy0 = rangeAxis.valueToJava2D(y0, dataArea,
                    plot.getRangeAxisEdge());
            double yy1 = rangeAxis.valueToJava2D(y1, dataArea,
                    plot.getRangeAxisEdge());

            RectangleEdge xAxisLocation = plot.getDomainAxisEdge();
            double x0 = intervalDataset.getStartXValue(series, item);
            double xx0 = domainAxis.valueToJava2D(x0, dataArea, xAxisLocation);

            double x1 = intervalDataset.getEndXValue(series, item);
            double xx1 = domainAxis.valueToJava2D(x1, dataArea, xAxisLocation);

            double intervalW = xx1 - xx0;  // this may be negative
            double baseX = xx0;
            if (this.centerBarAtStartValue) {
                baseX = baseX - intervalW / 2.0;
            }
            double m = getMargin();
            if (m > 0.0) {
                double cut = intervalW * getMargin();
                intervalW = intervalW - cut;
                baseX = baseX + (cut / 2);
            }

            double intervalH = Math.abs(yy0 - yy1);  // we don't need the sign

            PlotOrientation orientation = plot.getOrientation();

            int numSeries = dataset.getSeriesCount();
            double seriesBarWidth = intervalW / numSeries;  // may be negative

            Rectangle2D bar = null;
            if (orientation == PlotOrientation.HORIZONTAL) {
                double barY0 = baseX + (seriesBarWidth * series);
                double barY1 = barY0 + seriesBarWidth;
                double rx = Math.min(yy0, yy1);
                double rw = intervalH;
                double ry = Math.min(barY0, barY1);
                double rh = Math.abs(barY1 - barY0);
                bar = new Rectangle2D.Double(rx, ry, rw, rh);
            }
            else if (orientation == PlotOrientation.VERTICAL) {
                double barX0 = baseX + (seriesBarWidth * series);
                double barX1 = barX0 + seriesBarWidth;
                double rx = Math.min(barX0, barX1);
                double rw = Math.abs(barX1 - barX0);
                double ry = Math.min(yy0, yy1);
                double rh = intervalH;
                bar = new Rectangle2D.Double(rx, ry, rw, rh);
            }
            Paint itemPaint = getItemPaint(series, item);
            if (getGradientPaintTransformer()
                    != null && itemPaint instanceof GradientPaint) {
                GradientPaint gp = (GradientPaint) itemPaint;
                itemPaint = getGradientPaintTransformer().transform(gp, bar);
            }
            g2.setPaint(itemPaint);

            g2.fill(bar);
            if (isDrawBarOutline() && Math.abs(seriesBarWidth) > 3) {
                g2.setStroke(getItemOutlineStroke(series, item));
                g2.setPaint(getItemOutlinePaint(series, item));
                g2.draw(bar);
            }

            if (isItemLabelVisible(series, item)) {
                XYItemLabelGenerator generator = getItemLabelGenerator(series,
                        item);
                drawItemLabel(g2, dataset, series, item, plot, generator, bar,
                        y1 < 0.0);
            }

            // add an entity for the item...
            if (info != null) {
                EntityCollection entities = info.getOwner().getEntityCollection();
                if (entities != null) {
                    addEntity(entities, bar, dataset, series, item,
                            bar.getCenterX(), bar.getCenterY());
                }
            }

        }

        /**
         * Tests this renderer for equality with an arbitrary object, returning
         * <code>true</code> if <code>obj</code> is a
         * <code>ClusteredXYBarRenderer</code> with the same settings as this
         * renderer, and <code>false</code> otherwise.
         *
         * @param obj  the object (<code>null</code> permitted).
         *
         * @return A boolean.
         */
        public boolean equals(Object obj) {
            if (obj == this) {
                return true;
            }
            if (!(obj instanceof ClusteredXYBarRenderer)) {
                return false;
            }
            ClusteredXYBarRenderer that = (ClusteredXYBarRenderer) obj;
            if (this.centerBarAtStartValue != that.centerBarAtStartValue) {
                return false;
            }
            return super.equals(obj);
        }

        /**
         * 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();
        }

    }