/* ===========================================================

 * JFreeChart : a free chart library for the Java(tm) platform

 * ===========================================================

 *

 * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

 * in the United States and other countries.]

 *

 * ------------------------

 * StackedAreaRenderer.java

 * ------------------------

 * (C) Copyright 2002-2004, by Dan Rivett (d.rivett@ukonline.co.uk) and Contributors.

 *

 * Original Author:  Dan Rivett (adapted from AreaCategoryItemRenderer);

 * Contributor(s):   Jon Iles;

 *                   David Gilbert (for Object Refinery Limited);

 *                   Christian W. Zuckschwerdt;

 *

 * $Id: StackedAreaRenderer.java,v 1.1 2004/08/31 14:47:48 mungady Exp $

 *

 * Changes:

 * --------

 * 20-Sep-2002 : Version 1, contributed by Dan Rivett;

 * 24-Oct-2002 : Amendments for changes in CategoryDataset interface and CategoryToolTipGenerator

 *               interface (DG);

 * 01-Nov-2002 : Added tooltips (DG);

 * 06-Nov-2002 : Renamed drawCategoryItem(...) --> drawItem(...) and now using axis for

 *               category spacing.

 *               Renamed StackedAreaCategoryItemRenderer --> StackedAreaRenderer (DG);

 * 26-Nov-2002 : Switched CategoryDataset --> 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);

 * 13-May-2003 : Modified to take into account the plot orientation (DG);

 * 30-Jul-2003 : Modified entity constructor (CZ);

 * 07-Oct-2003 : Added renderer state (DG);

 * 29-Apr-2004 : Added getRangeExtent() override (DG);

 * 

 */



package org.jfree.chart.renderer.category;



import java.awt.Graphics2D;

import java.awt.Polygon;

import java.awt.Shape;

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.CategoryItemEntity;

import org.jfree.chart.entity.EntityCollection;

import org.jfree.chart.labels.CategoryToolTipGenerator;

import org.jfree.chart.plot.CategoryPlot;

import org.jfree.chart.plot.PlotOrientation;

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 area charts for a {@link org.jfree.chart.plot.CategoryPlot}.

 *

 * @author Dan Rivett

 */

public class StackedAreaRenderer extends AreaRenderer 

                                 implements Cloneable, PublicCloneable, Serializable {



    /**

     * Creates a new renderer.

     */

    public StackedAreaRenderer() {

        super();

    }



    /**

     * Returns the range of values the renderer requires to display all the items from the

     * specified dataset.

     * 

     * @param dataset  the dataset (<code>null</code> not permitted).

     * 

     * @return The range (or <code>null</code> if the dataset is empty).

     */

    public Range getRangeExtent(CategoryDataset dataset) {

        return DatasetUtilities.findStackedRangeExtent(dataset);   

    }



    /**

     * Draw a single data item.

     *

     * @param g2  the graphics device.

     * @param state  the renderer state.

     * @param dataArea  the data plot area.

     * @param plot  the plot.

     * @param domainAxis  the domain axis.

     * @param rangeAxis  the range axis.

     * @param dataset  the data.

     * @param row  the row index (zero-based).

     * @param column  the column index (zero-based).

     */

    public void drawItem(Graphics2D g2,

                         CategoryItemRendererState state,

                         Rectangle2D dataArea,

                         CategoryPlot plot,

                         CategoryAxis domainAxis,

                         ValueAxis rangeAxis,

                         CategoryDataset dataset,

                         int row,

                         int column) {



        // plot non-null values...

        Number value = dataset.getValue(row, column);

        if (value == null) {

            return;

        }



        // leave the y values (y1, y0) untranslated as it is going to be be stacked

        // up later by previous series values, after this it will be translated.

        double x1 = domainAxis.getCategoryMiddle(

            column, getColumnCount(), dataArea, plot.getDomainAxisEdge()

        );

        double y1 = 0.0;  // calculate later

        double y1Untranslated = value.doubleValue();



        g2.setPaint(getItemPaint(row, column));

        g2.setStroke(getItemStroke(row, column));



        if (column != 0) {



            Number previousValue = dataset.getValue(row, column - 1);

            if (previousValue != null) {



                double x0 = domainAxis.getCategoryMiddle(

                    column - 1, getColumnCount(), dataArea, plot.getDomainAxisEdge()

                );

                double y0Untranslated = previousValue.doubleValue();



                // Get the previous height, but this will be different for both y0 and y1 as

                // the previous series values could differ.

                double previousHeightx0Untranslated = getPreviousHeight(dataset, row, column - 1);

                double previousHeightx1Untranslated = getPreviousHeight(dataset, row, column);



                // Now stack the current y values on top of the previous values.

                y0Untranslated += previousHeightx0Untranslated;

                y1Untranslated += previousHeightx1Untranslated;



                // Now translate the previous heights

                RectangleEdge location = plot.getRangeAxisEdge();

                double previousHeightx0 = rangeAxis.valueToJava2D(

                    previousHeightx0Untranslated, dataArea, location

                );

                double previousHeightx1 = rangeAxis.valueToJava2D(

                    previousHeightx1Untranslated, dataArea, location

                );



                // Now translate the current y values.

                double y0 = rangeAxis.valueToJava2D(y0Untranslated, dataArea, location);

                y1 = rangeAxis.valueToJava2D(y1Untranslated, dataArea, location);



                Polygon p = null;

                PlotOrientation orientation = plot.getOrientation();

                if (orientation == PlotOrientation.HORIZONTAL) {

                    p = new Polygon();

                    p.addPoint((int) y0, (int) x0);

                    p.addPoint((int) y1, (int) x1);

                    p.addPoint((int) previousHeightx1, (int) x1);

                    p.addPoint((int) previousHeightx0, (int) x0);

                }

                else if (orientation == PlotOrientation.VERTICAL) {

                    p = new Polygon();

                    p.addPoint((int) x0, (int) y0);

                    p.addPoint((int) x1, (int) y1);

                    p.addPoint((int) x1, (int) previousHeightx1);

                    p.addPoint((int) x0, (int) previousHeightx0);

                }

                g2.setPaint(getItemPaint(row, column));

                g2.setStroke(getItemStroke(row, column));

                g2.fill(p);

            }



        }



        // collect entity and tool tip information...

        if (state.getInfo() != null) {

            EntityCollection entities = state.getInfo().getOwner().getEntityCollection();

            Shape shape = new Rectangle2D.Double(x1 - 3.0, y1 - 3.0, 6.0, 6.0);

            if (entities != null && shape != null) {

                String tip = null;

                CategoryToolTipGenerator tipster = getToolTipGenerator(row, column);

                if (tipster != null) {

                    tip = tipster.generateToolTip(dataset, row, column);

                }

                String url = null;

                if (getItemURLGenerator(row, column) != null) {

                    url = getItemURLGenerator(row, column).generateURL(dataset, row, column);

                }

                CategoryItemEntity entity = new CategoryItemEntity(

                    shape, tip, url, dataset, row, dataset.getColumnKey(column), column

                );

                entities.addEntity(entity);

            }

        }



    }



    /**

     * Calculates the stacked value of the all series up to, but not including <code>series</code>

     * for the specified category, <code>category</code>.  It returns 0.0 if <code>series</code>

     * is the first series, i.e. 0.

     *

     * @param data  the data.

     * @param series  the series.

     * @param category  the category.

     *

     * @return double returns a cumulative value for all series' values up to but excluding

     *                <code>series</code> for Object <code>category</code>.

     */

    protected double getPreviousHeight(CategoryDataset data, int series, int category) {



        double result = 0.0;



        Number tmp;

        for (int i = 0; i < series; i++) {

            tmp = data.getValue(i, category);

            if (tmp != null) {

                result += tmp.doubleValue();

            }

        }



        return result;



    }



}

