/* ===========================================================
 * 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.]
 *
 * -----------------------
 * StackedBarRenderer.java
 * -----------------------
 * (C) Copyright 2000-2007, 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);
    }

}
