gt:         for (int i = 0; i < series; i++) {
context: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2005, 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.]
   *
   * ------------------------
   * StackedAreaRenderer.java
   * ------------------------
   * (C) Copyright 2002-2005, 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 1.6.2.2 2005/10/25 20:54:16 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);
   * 05-Nov-2004 : Modified drawItem() signature (DG);
   * 07-Jan-2005 : Renamed getRangeExtent() --> findRangeBounds() (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.EntityCollection;
  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 {
  
      /** For serialization. */
      private static final long serialVersionUID = -3595635038460823663L;
       
      /**
       * 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 findRangeBounds(CategoryDataset dataset) {
          return DatasetUtilities.findStackedRangeBounds(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).
       * @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) {
  
          // 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);
              }
  
          }
  
          // add an item entity, if this information is being collected
          EntityCollection entities = state.getEntityCollection();
          if (entities != null) {
              Shape shape = new Rectangle2D.Double(x1 - 3.0, y1 - 3.0, 6.0, 6.0);
              addItemEntity(entities, dataset, row, column, shape);
          }
  
      }
  
      /**
       * 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;
  