Source for org.jfree.chart.renderer.xy.XYDifferenceRenderer

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
   6:  *
   7:  * Project Info:  http://www.jfree.org/jfreechart/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  *
  27:  * -------------------------
  28:  * XYDifferenceRenderer.java
  29:  * -------------------------
  30:  * (C) Copyright 2003-2007, by Object Refinery Limited and Contributors.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   Richard West, Advanced Micro Devices, Inc. (major rewrite 
  34:  *                   of difference drawing algorithm);
  35:  *
  36:  * Changes:
  37:  * --------
  38:  * 30-Apr-2003 : Version 1 (DG);
  39:  * 30-Jul-2003 : Modified entity constructor (CZ);
  40:  * 20-Aug-2003 : Implemented Cloneable and PublicCloneable (DG);
  41:  * 16-Sep-2003 : Changed ChartRenderingInfo --> PlotRenderingInfo (DG);
  42:  * 09-Feb-2004 : Updated to support horizontal plot orientation (DG);
  43:  * 10-Feb-2004 : Added default constructor, setter methods and updated 
  44:  *               Javadocs (DG);
  45:  * 25-Feb-2004 : Replaced CrosshairInfo with CrosshairState (DG);
  46:  * 30-Mar-2004 : Fixed bug in getNegativePaint() method (DG);
  47:  * 15-Jul-2004 : Switched getX() with getXValue() and getY() with 
  48:  *               getYValue() (DG);
  49:  * 25-Aug-2004 : Fixed a bug preventing the use of crosshairs (DG);
  50:  * 11-Nov-2004 : Now uses ShapeUtilities to translate shapes (DG);
  51:  * 19-Jan-2005 : Now accesses only primitive values from dataset (DG);
  52:  * 22-Feb-2005 : Override getLegendItem(int, int) to return "line" items (DG);
  53:  * 13-Apr-2005 : Fixed shape positioning bug (id = 1182062) (DG);
  54:  * 20-Apr-2005 : Use generators for legend tooltips and URLs (DG);
  55:  * 04-May-2005 : Override equals() method, renamed get/setPlotShapes() -->
  56:  *               get/setShapesVisible (DG);
  57:  * 09-Jun-2005 : Updated equals() to handle GradientPaint (DG);
  58:  * 16-Jun-2005 : Fix bug (1221021) affecting stroke used for each series (DG);
  59:  * ------------- JFREECHART 1.0.x ---------------------------------------------
  60:  * 24-Jan-2007 : Added flag to allow rounding of x-coordinates, and fixed
  61:  *               bug in clone() (DG);
  62:  * 05-Feb-2007 : Added an extra call to updateCrosshairValues() in 
  63:  *               drawItemPass1(), to fix bug 1564967 (DG);
  64:  * 06-Feb-2007 : Fixed bug 1086307, crosshairs with multiple axes (DG);
  65:  * 08-Mar-2007 : Fixed entity generation (DG);
  66:  * 20-Apr-2007 : Updated getLegendItem() for renderer change (DG);
  67:  * 23-Apr-2007 : Rewrite of difference drawing algorithm to allow use of 
  68:  *               series with disjoint x-values (RW);
  69:  * 04-May-2007 : Set processVisibleItemsOnly flag to false (DG);
  70:  * 17-May-2007 : Set datasetIndex and seriesIndex in getLegendItem() (DG);
  71:  * 18-May-2007 : Set dataset and seriesKey for LegendItem (DG);
  72:  * 05-Nov-2007 : Draw item labels if visible (RW);
  73:  * 
  74:  */
  75: 
  76: package org.jfree.chart.renderer.xy;
  77: 
  78: import java.awt.Color;
  79: import java.awt.Graphics2D;
  80: import java.awt.Paint;
  81: import java.awt.Shape;
  82: import java.awt.Stroke;
  83: import java.awt.geom.GeneralPath;
  84: import java.awt.geom.Line2D;
  85: import java.awt.geom.Rectangle2D;
  86: import java.io.IOException;
  87: import java.io.ObjectInputStream;
  88: import java.io.ObjectOutputStream;
  89: import java.io.Serializable;
  90: import java.util.Collections;
  91: import java.util.LinkedList;
  92: 
  93: import org.jfree.chart.LegendItem;
  94: import org.jfree.chart.axis.ValueAxis;
  95: import org.jfree.chart.entity.EntityCollection;
  96: import org.jfree.chart.entity.XYItemEntity;
  97: import org.jfree.chart.event.RendererChangeEvent;
  98: import org.jfree.chart.labels.XYToolTipGenerator;
  99: import org.jfree.chart.plot.CrosshairState;
 100: import org.jfree.chart.plot.PlotOrientation;
 101: import org.jfree.chart.plot.PlotRenderingInfo;
 102: import org.jfree.chart.plot.XYPlot;
 103: import org.jfree.chart.urls.XYURLGenerator;
 104: import org.jfree.data.xy.XYDataset;
 105: import org.jfree.io.SerialUtilities;
 106: import org.jfree.ui.RectangleEdge;
 107: import org.jfree.util.PaintUtilities;
 108: import org.jfree.util.PublicCloneable;
 109: import org.jfree.util.ShapeUtilities;
 110: 
 111: /**
 112:  * A renderer for an {@link XYPlot} that highlights the differences between two
 113:  * series.
 114:  */
 115: public class XYDifferenceRenderer extends AbstractXYItemRenderer 
 116:                                   implements XYItemRenderer, 
 117:                                              Cloneable,
 118:                                              PublicCloneable,
 119:                                              Serializable {
 120: 
 121:     /** For serialization. */
 122:     private static final long serialVersionUID = -8447915602375584857L;
 123:     
 124:     /** The paint used to highlight positive differences (y(0) > y(1)). */
 125:     private transient Paint positivePaint;
 126: 
 127:     /** The paint used to highlight negative differences (y(0) < y(1)). */
 128:     private transient Paint negativePaint;
 129: 
 130:     /** Display shapes at each point? */
 131:     private boolean shapesVisible;
 132:     
 133:     /** The shape to display in the legend item. */
 134:     private transient Shape legendLine;
 135: 
 136:     /**
 137:      * This flag controls whether or not the x-coordinates (in Java2D space) 
 138:      * are rounded to integers.  When set to true, this can avoid the vertical
 139:      * striping that anti-aliasing can generate.  However, the rounding may not
 140:      * be appropriate for output in high resolution formats (for example, 
 141:      * vector graphics formats such as SVG and PDF).
 142:      * 
 143:      * @since 1.0.4
 144:      */
 145:     private boolean roundXCoordinates;
 146: 
 147:     /**
 148:      * Creates a new renderer with default attributes.
 149:      */
 150:     public XYDifferenceRenderer() {
 151:         this(Color.green, Color.red, false);
 152:     }
 153:     
 154:     /**
 155:      * Creates a new renderer.
 156:      *
 157:      * @param positivePaint  the highlight color for positive differences 
 158:      *                       (<code>null</code> not permitted).
 159:      * @param negativePaint  the highlight color for negative differences 
 160:      *                       (<code>null</code> not permitted).
 161:      * @param shapes  draw shapes?
 162:      */
 163:     public XYDifferenceRenderer(Paint positivePaint, Paint negativePaint, 
 164:                                 boolean shapes) {
 165:         if (positivePaint == null) {
 166:             throw new IllegalArgumentException(
 167:                     "Null 'positivePaint' argument.");
 168:         }
 169:         if (negativePaint == null) {
 170:             throw new IllegalArgumentException(
 171:                     "Null 'negativePaint' argument.");
 172:         }
 173:         this.positivePaint = positivePaint;
 174:         this.negativePaint = negativePaint;
 175:         this.shapesVisible = shapes;
 176:         this.legendLine = new Line2D.Double(-7.0, 0.0, 7.0, 0.0);
 177:         this.roundXCoordinates = false;
 178:     }
 179: 
 180:     /**
 181:      * Returns the paint used to highlight positive differences.
 182:      *
 183:      * @return The paint (never <code>null</code>).
 184:      * 
 185:      * @see #setPositivePaint(Paint)
 186:      */
 187:     public Paint getPositivePaint() {
 188:         return this.positivePaint;
 189:     }
 190: 
 191:     /**
 192:      * Sets the paint used to highlight positive differences.
 193:      * 
 194:      * @param paint  the paint (<code>null</code> not permitted).
 195:      * 
 196:      * @see #getPositivePaint()
 197:      */
 198:     public void setPositivePaint(Paint paint) {
 199:         if (paint == null) {
 200:             throw new IllegalArgumentException("Null 'paint' argument.");
 201:         }
 202:         this.positivePaint = paint;
 203:         notifyListeners(new RendererChangeEvent(this));
 204:     }
 205: 
 206:     /**
 207:      * Returns the paint used to highlight negative differences.
 208:      *
 209:      * @return The paint (never <code>null</code>).
 210:      * 
 211:      * @see #setNegativePaint(Paint)
 212:      */
 213:     public Paint getNegativePaint() {
 214:         return this.negativePaint;
 215:     }
 216:     
 217:     /**
 218:      * Sets the paint used to highlight negative differences.
 219:      * 
 220:      * @param paint  the paint (<code>null</code> not permitted).
 221:      * 
 222:      * @see #getNegativePaint()
 223:      */
 224:     public void setNegativePaint(Paint paint) {
 225:         if (paint == null) {
 226:             throw new IllegalArgumentException("Null 'paint' argument.");
 227:         }
 228:         this.negativePaint = paint;
 229:         notifyListeners(new RendererChangeEvent(this));
 230:     }
 231: 
 232:     /**
 233:      * Returns a flag that controls whether or not shapes are drawn for each 
 234:      * data value.
 235:      * 
 236:      * @return A boolean.
 237:      * 
 238:      * @see #setShapesVisible(boolean)
 239:      */
 240:     public boolean getShapesVisible() {
 241:         return this.shapesVisible;
 242:     }
 243: 
 244:     /**
 245:      * Sets a flag that controls whether or not shapes are drawn for each 
 246:      * data value.
 247:      * 
 248:      * @param flag  the flag.
 249:      * 
 250:      * @see #getShapesVisible()
 251:      */
 252:     public void setShapesVisible(boolean flag) {
 253:         this.shapesVisible = flag;
 254:         notifyListeners(new RendererChangeEvent(this));
 255:     }
 256:     
 257:     /**
 258:      * Returns the shape used to represent a line in the legend.
 259:      * 
 260:      * @return The legend line (never <code>null</code>).
 261:      * 
 262:      * @see #setLegendLine(Shape)
 263:      */
 264:     public Shape getLegendLine() {
 265:         return this.legendLine;   
 266:     }
 267:     
 268:     /**
 269:      * Sets the shape used as a line in each legend item and sends a 
 270:      * {@link RendererChangeEvent} to all registered listeners.
 271:      * 
 272:      * @param line  the line (<code>null</code> not permitted).
 273:      * 
 274:      * @see #getLegendLine()
 275:      */
 276:     public void setLegendLine(Shape line) {
 277:         if (line == null) {
 278:             throw new IllegalArgumentException("Null 'line' argument.");   
 279:         }
 280:         this.legendLine = line;
 281:         notifyListeners(new RendererChangeEvent(this));
 282:     }
 283: 
 284:     /**
 285:      * Returns the flag that controls whether or not the x-coordinates (in
 286:      * Java2D space) are rounded to integer values.
 287:      * 
 288:      * @return The flag.
 289:      * 
 290:      * @since 1.0.4
 291:      * 
 292:      * @see #setRoundXCoordinates(boolean)
 293:      */
 294:     public boolean getRoundXCoordinates() {
 295:         return this.roundXCoordinates;
 296:     }
 297:     
 298:     /**
 299:      * Sets the flag that controls whether or not the x-coordinates (in 
 300:      * Java2D space) are rounded to integer values, and sends a 
 301:      * {@link RendererChangeEvent} to all registered listeners.
 302:      * 
 303:      * @param round  the new flag value.
 304:      * 
 305:      * @since 1.0.4
 306:      * 
 307:      * @see #getRoundXCoordinates()
 308:      */
 309:     public void setRoundXCoordinates(boolean round) {
 310:         this.roundXCoordinates = round;
 311:         notifyListeners(new RendererChangeEvent(this));
 312:     }
 313: 
 314:     /**
 315:      * Initialises the renderer and returns a state object that should be 
 316:      * passed to subsequent calls to the drawItem() method.  This method will 
 317:      * be called before the first item is rendered, giving the renderer an 
 318:      * opportunity to initialise any state information it wants to maintain.  
 319:      * The renderer can do nothing if it chooses.
 320:      *
 321:      * @param g2  the graphics device.
 322:      * @param dataArea  the area inside the axes.
 323:      * @param plot  the plot.
 324:      * @param data  the data.
 325:      * @param info  an optional info collection object to return data back to 
 326:      *              the caller.
 327:      *
 328:      * @return A state object.
 329:      */
 330:     public XYItemRendererState initialise(Graphics2D g2,
 331:                                           Rectangle2D dataArea,
 332:                                           XYPlot plot,
 333:                                           XYDataset data,
 334:                                           PlotRenderingInfo info) {
 335: 
 336:         XYItemRendererState state = super.initialise(g2, dataArea, plot, data, 
 337:                 info);
 338:         state.setProcessVisibleItemsOnly(false);
 339:         return state;
 340: 
 341:     }
 342: 
 343:     /**
 344:      * Returns <code>2</code>, the number of passes required by the renderer.  
 345:      * The {@link XYPlot} will run through the dataset this number of times.
 346:      * 
 347:      * @return The number of passes required by the renderer.
 348:      */
 349:     public int getPassCount() {
 350:         return 2;
 351:     }
 352:     
 353:     /**
 354:      * Draws the visual representation of a single data item.
 355:      *
 356:      * @param g2  the graphics device.
 357:      * @param state  the renderer state.
 358:      * @param dataArea  the area within which the data is being drawn.
 359:      * @param info  collects information about the drawing.
 360:      * @param plot  the plot (can be used to obtain standard color 
 361:      *              information etc).
 362:      * @param domainAxis  the domain (horizontal) axis.
 363:      * @param rangeAxis  the range (vertical) axis.
 364:      * @param dataset  the dataset.
 365:      * @param series  the series index (zero-based).
 366:      * @param item  the item index (zero-based).
 367:      * @param crosshairState  crosshair information for the plot 
 368:      *                        (<code>null</code> permitted).
 369:      * @param pass  the pass index.
 370:      */
 371:     public void drawItem(Graphics2D g2,
 372:                          XYItemRendererState state,
 373:                          Rectangle2D dataArea,
 374:                          PlotRenderingInfo info,
 375:                          XYPlot plot,
 376:                          ValueAxis domainAxis,
 377:                          ValueAxis rangeAxis,
 378:                          XYDataset dataset,
 379:                          int series,
 380:                          int item,
 381:                          CrosshairState crosshairState,
 382:                          int pass) {
 383: 
 384:         if (pass == 0) {
 385:             drawItemPass0(g2, dataArea, info, plot, domainAxis, rangeAxis, 
 386:                     dataset, series, item, crosshairState);
 387:         }
 388:         else if (pass == 1) {
 389:             drawItemPass1(g2, dataArea, info, plot, domainAxis, rangeAxis, 
 390:                     dataset, series, item, crosshairState);
 391:         }
 392: 
 393:     }
 394: 
 395:     /**
 396:      * Draws the visual representation of a single data item, first pass.
 397:      *
 398:      * @param x_graphics  the graphics device.
 399:      * @param x_dataArea  the area within which the data is being drawn.
 400:      * @param x_info  collects information about the drawing.
 401:      * @param x_plot  the plot (can be used to obtain standard color 
 402:      *                information etc).
 403:      * @param x_domainAxis  the domain (horizontal) axis.
 404:      * @param x_rangeAxis  the range (vertical) axis.
 405:      * @param x_dataset  the dataset.
 406:      * @param x_series  the series index (zero-based).
 407:      * @param x_item  the item index (zero-based).
 408:      * @param x_crosshairState  crosshair information for the plot 
 409:      *                          (<code>null</code> permitted).
 410:      */
 411:     protected void drawItemPass0(Graphics2D x_graphics,
 412:                                  Rectangle2D x_dataArea,
 413:                                  PlotRenderingInfo x_info,
 414:                                  XYPlot x_plot,
 415:                                  ValueAxis x_domainAxis,
 416:                                  ValueAxis x_rangeAxis,
 417:                                  XYDataset x_dataset,
 418:                                  int x_series,
 419:                                  int x_item,
 420:                                  CrosshairState x_crosshairState) {
 421: 
 422:         if (!((0 == x_series) && (0 == x_item))) {
 423:             return;
 424:         }
 425: 
 426:         boolean b_impliedZeroSubtrahend = (1 == x_dataset.getSeriesCount());
 427: 
 428:         // check if either series is a degenerate case (i.e. less than 2 points)
 429:         if (isEitherSeriesDegenerate(x_dataset, b_impliedZeroSubtrahend)) {
 430:             return;
 431:         }
 432: 
 433:         // check if series are disjoint (i.e. domain-spans do not overlap)
 434:         if (!b_impliedZeroSubtrahend && areSeriesDisjoint(x_dataset)) {
 435:             return;
 436:         }
 437: 
 438:         // polygon definitions
 439:         LinkedList l_minuendXs    = new LinkedList();
 440:         LinkedList l_minuendYs    = new LinkedList();
 441:         LinkedList l_subtrahendXs = new LinkedList();
 442:         LinkedList l_subtrahendYs = new LinkedList();
 443:         LinkedList l_polygonXs    = new LinkedList();
 444:         LinkedList l_polygonYs    = new LinkedList();
 445: 
 446:         // state
 447:         int l_minuendItem      = 0;
 448:         int l_minuendItemCount = x_dataset.getItemCount(0);
 449:         Double l_minuendCurX   = null;
 450:         Double l_minuendNextX  = null;
 451:         Double l_minuendCurY   = null;
 452:         Double l_minuendNextY  = null;
 453:         double l_minuendMaxY   = Double.NEGATIVE_INFINITY;
 454:         double l_minuendMinY   = Double.POSITIVE_INFINITY;
 455: 
 456:         int l_subtrahendItem      = 0;
 457:         int l_subtrahendItemCount = 0; // actual value set below
 458:         Double l_subtrahendCurX   = null;
 459:         Double l_subtrahendNextX  = null;
 460:         Double l_subtrahendCurY   = null;
 461:         Double l_subtrahendNextY  = null;
 462:         double l_subtrahendMaxY   = Double.NEGATIVE_INFINITY;
 463:         double l_subtrahendMinY   = Double.POSITIVE_INFINITY;
 464: 
 465:         // if a subtrahend is not specified, assume it is zero
 466:         if (b_impliedZeroSubtrahend) {
 467:             l_subtrahendItem      = 0;
 468:             l_subtrahendItemCount = 2;
 469:             l_subtrahendCurX      = new Double(x_dataset.getXValue(0, 0));
 470:             l_subtrahendNextX     = new Double(x_dataset.getXValue(0, 
 471:                     (l_minuendItemCount - 1)));
 472:             l_subtrahendCurY      = new Double(0.0);
 473:             l_subtrahendNextY     = new Double(0.0);
 474:             l_subtrahendMaxY      = 0.0;
 475:             l_subtrahendMinY      = 0.0;
 476: 
 477:             l_subtrahendXs.add(l_subtrahendCurX);
 478:             l_subtrahendYs.add(l_subtrahendCurY);
 479:         }
 480:         else {
 481:             l_subtrahendItemCount = x_dataset.getItemCount(1);
 482:         }
 483: 
 484:         boolean b_minuendDone           = false;
 485:         boolean b_minuendAdvanced       = true;
 486:         boolean b_minuendAtIntersect    = false;
 487:         boolean b_minuendFastForward    = false;
 488:         boolean b_subtrahendDone        = false;
 489:         boolean b_subtrahendAdvanced    = true;
 490:         boolean b_subtrahendAtIntersect = false;
 491:         boolean b_subtrahendFastForward = false;
 492:         boolean b_colinear              = false;
 493: 
 494:         boolean b_positive;
 495: 
 496:         // coordinate pairs
 497:         double l_x1 = 0.0, l_y1 = 0.0; // current minuend point
 498:         double l_x2 = 0.0, l_y2 = 0.0; // next minuend point
 499:         double l_x3 = 0.0, l_y3 = 0.0; // current subtrahend point
 500:         double l_x4 = 0.0, l_y4 = 0.0; // next subtrahend point
 501: 
 502:         // fast-forward through leading tails
 503:         boolean b_fastForwardDone = false;
 504:         while (!b_fastForwardDone) {
 505:             // get the x and y coordinates
 506:             l_x1 = x_dataset.getXValue(0, l_minuendItem);
 507:             l_y1 = x_dataset.getYValue(0, l_minuendItem);
 508:             l_x2 = x_dataset.getXValue(0, l_minuendItem + 1);
 509:             l_y2 = x_dataset.getYValue(0, l_minuendItem + 1);
 510: 
 511:             l_minuendCurX  = new Double(l_x1);
 512:             l_minuendCurY  = new Double(l_y1);
 513:             l_minuendNextX = new Double(l_x2);
 514:             l_minuendNextY = new Double(l_y2);
 515: 
 516:             if (b_impliedZeroSubtrahend) {
 517:                 l_x3 = l_subtrahendCurX.doubleValue();
 518:                 l_y3 = l_subtrahendCurY.doubleValue();
 519:                 l_x4 = l_subtrahendNextX.doubleValue();
 520:                 l_y4 = l_subtrahendNextY.doubleValue();
 521:             }
 522:             else {
 523:                 l_x3 = x_dataset.getXValue(1, l_subtrahendItem);
 524:                 l_y3 = x_dataset.getYValue(1, l_subtrahendItem);
 525:                 l_x4 = x_dataset.getXValue(1, l_subtrahendItem + 1);
 526:                 l_y4 = x_dataset.getYValue(1, l_subtrahendItem + 1);
 527: 
 528:                 l_subtrahendCurX  = new Double(l_x3);
 529:                 l_subtrahendCurY  = new Double(l_y3);
 530:                 l_subtrahendNextX = new Double(l_x4);
 531:                 l_subtrahendNextY = new Double(l_y4);
 532:             }
 533: 
 534:             if (l_x2 <= l_x3) {
 535:                 // minuend needs to be fast forwarded
 536:                 l_minuendItem++;
 537:                 b_minuendFastForward = true;
 538:                 continue;
 539:             }
 540: 
 541:             if (l_x4 <= l_x1) {
 542:                 // subtrahend needs to be fast forwarded
 543:                 l_subtrahendItem++;
 544:                 b_subtrahendFastForward = true;
 545:                 continue;
 546:             }
 547: 
 548:             // check if initial polygon needs to be clipped
 549:             if ((l_x3 < l_x1) && (l_x1 < l_x4)) {
 550:                 // project onto subtrahend
 551:                 double l_slope   = (l_y4 - l_y3) / (l_x4 - l_x3);
 552:                 l_subtrahendCurX = l_minuendCurX;
 553:                 l_subtrahendCurY = new Double((l_slope * l_x1) 
 554:                         + (l_y3 - (l_slope * l_x3)));
 555: 
 556:                 l_subtrahendXs.add(l_subtrahendCurX);
 557:                 l_subtrahendYs.add(l_subtrahendCurY);
 558:             }
 559: 
 560:             if ((l_x1 < l_x3) && (l_x3 < l_x2)) {
 561:                 // project onto minuend
 562:                 double l_slope = (l_y2 - l_y1) / (l_x2 - l_x1);
 563:                 l_minuendCurX  = l_subtrahendCurX;
 564:                 l_minuendCurY  = new Double((l_slope * l_x3) 
 565:                         + (l_y1 - (l_slope * l_x1)));
 566: 
 567:                 l_minuendXs.add(l_minuendCurX);
 568:                 l_minuendYs.add(l_minuendCurY);
 569:             }
 570: 
 571:             l_minuendMaxY    = l_minuendCurY.doubleValue();
 572:             l_minuendMinY    = l_minuendCurY.doubleValue();
 573:             l_subtrahendMaxY = l_subtrahendCurY.doubleValue();
 574:             l_subtrahendMinY = l_subtrahendCurY.doubleValue();
 575: 
 576:             b_fastForwardDone = true;
 577:         }
 578: 
 579:         // start of algorithm
 580:         while (!b_minuendDone && !b_subtrahendDone) {
 581:             if (!b_minuendDone && !b_minuendFastForward && b_minuendAdvanced) {
 582:                 l_x1 = x_dataset.getXValue(0, l_minuendItem);
 583:                 l_y1 = x_dataset.getYValue(0, l_minuendItem);
 584:                 l_minuendCurX = new Double(l_x1);
 585:                 l_minuendCurY = new Double(l_y1);
 586: 
 587:                 if (!b_minuendAtIntersect) {
 588:                     l_minuendXs.add(l_minuendCurX);
 589:                     l_minuendYs.add(l_minuendCurY);
 590:                 }
 591: 
 592:                 l_minuendMaxY = Math.max(l_minuendMaxY, l_y1);
 593:                 l_minuendMinY = Math.min(l_minuendMinY, l_y1);
 594: 
 595:                 l_x2 = x_dataset.getXValue(0, l_minuendItem + 1);
 596:                 l_y2 = x_dataset.getYValue(0, l_minuendItem + 1);
 597:                 l_minuendNextX = new Double(l_x2);
 598:                 l_minuendNextY = new Double(l_y2);
 599:             }
 600: 
 601:             // never updated the subtrahend if it is implied to be zero
 602:             if (!b_impliedZeroSubtrahend && !b_subtrahendDone 
 603:                     && !b_subtrahendFastForward && b_subtrahendAdvanced) {
 604:                 l_x3 = x_dataset.getXValue(1, l_subtrahendItem);
 605:                 l_y3 = x_dataset.getYValue(1, l_subtrahendItem);
 606:                 l_subtrahendCurX = new Double(l_x3);
 607:                 l_subtrahendCurY = new Double(l_y3);
 608: 
 609:                 if (!b_subtrahendAtIntersect) {
 610:                     l_subtrahendXs.add(l_subtrahendCurX);
 611:                     l_subtrahendYs.add(l_subtrahendCurY);
 612:                 }
 613: 
 614:                 l_subtrahendMaxY = Math.max(l_subtrahendMaxY, l_y3);
 615:                 l_subtrahendMinY = Math.min(l_subtrahendMinY, l_y3);
 616: 
 617:                 l_x4 = x_dataset.getXValue(1, l_subtrahendItem + 1);
 618:                 l_y4 = x_dataset.getYValue(1, l_subtrahendItem + 1);
 619:                 l_subtrahendNextX = new Double(l_x4);
 620:                 l_subtrahendNextY = new Double(l_y4);
 621:             }
 622: 
 623:             // deassert b_*FastForward (only matters for 1st time through loop)
 624:             b_minuendFastForward    = false;
 625:             b_subtrahendFastForward = false;
 626: 
 627:             Double l_intersectX = null;
 628:             Double l_intersectY = null;
 629:             boolean b_intersect = false;
 630: 
 631:             b_minuendAtIntersect    = false;
 632:             b_subtrahendAtIntersect = false;
 633: 
 634:             // check for intersect
 635:             if ((l_x2 == l_x4) && (l_y2 == l_y4)) {
 636:                 // check if line segments are colinear
 637:                 if ((l_x1 == l_x3) && (l_y1 == l_y3)) {
 638:                     b_colinear = true;
 639:                 }
 640:                 else {
 641:                     // the intersect is at the next point for both the minuend 
 642:                     // and subtrahend
 643:                     l_intersectX = new Double(l_x2);
 644:                     l_intersectY = new Double(l_y2);
 645: 
 646:                     b_intersect             = true;
 647:                     b_minuendAtIntersect    = true;
 648:                     b_subtrahendAtIntersect = true;
 649:                  }
 650:             }
 651:             else {
 652:                 // compute common denominator
 653:                 double l_denominator = ((l_y4 - l_y3) * (l_x2 - l_x1)) 
 654:                         - ((l_x4 - l_x3) * (l_y2 - l_y1));
 655: 
 656:                 // compute common deltas
 657:                 double l_deltaY = l_y1 - l_y3;
 658:                 double l_deltaX = l_x1 - l_x3;
 659: 
 660:                 // compute numerators
 661:                 double l_numeratorA = ((l_x4 - l_x3) * l_deltaY) 
 662:                         - ((l_y4 - l_y3) * l_deltaX);
 663:                 double l_numeratorB = ((l_x2 - l_x1) * l_deltaY) 
 664:                         - ((l_y2 - l_y1) * l_deltaX);
 665: 
 666:                 // check if line segments are colinear
 667:                 if ((0 == l_numeratorA) && (0 == l_numeratorB) 
 668:                         && (0 == l_denominator)) {
 669:                     b_colinear = true;
 670:                 }
 671:                 else {
 672:                     // check if previously colinear
 673:                     if (b_colinear) {
 674:                         // clear colinear points and flag
 675:                         l_minuendXs.clear();
 676:                         l_minuendYs.clear();
 677:                         l_subtrahendXs.clear();
 678:                         l_subtrahendYs.clear();
 679:                         l_polygonXs.clear();
 680:                         l_polygonYs.clear();
 681: 
 682:                         b_colinear = false;
 683: 
 684:                         // set new starting point for the polygon
 685:                         boolean b_useMinuend = ((l_x3 <= l_x1) 
 686:                                 && (l_x1 <= l_x4));
 687:                         l_polygonXs.add(b_useMinuend ? l_minuendCurX 
 688:                                 : l_subtrahendCurX);
 689:                         l_polygonYs.add(b_useMinuend ? l_minuendCurY 
 690:                                 : l_subtrahendCurY);
 691:                     }
 692: 
 693:                     // compute slope components
 694:                     double l_slopeA = l_numeratorA / l_denominator;
 695:                     double l_slopeB = l_numeratorB / l_denominator;
 696: 
 697:                     // check if the line segments intersect
 698:                     if ((0 < l_slopeA) && (l_slopeA <= 1) && (0 < l_slopeB) 
 699:                             && (l_slopeB <= 1)) {
 700:                         // compute the point of intersection
 701:                         double l_xi = l_x1 + (l_slopeA * (l_x2 - l_x1));
 702:                         double l_yi = l_y1 + (l_slopeA * (l_y2 - l_y1));
 703: 
 704:                         l_intersectX            = new Double(l_xi);
 705:                         l_intersectY            = new Double(l_yi);
 706:                         b_intersect             = true;
 707:                         b_minuendAtIntersect    = ((l_xi == l_x2) 
 708:                                 && (l_yi == l_y2));
 709:                         b_subtrahendAtIntersect = ((l_xi == l_x4) 
 710:                                 && (l_yi == l_y4));
 711: 
 712:                         // advance minuend and subtrahend to intesect
 713:                         l_minuendCurX    = l_intersectX;
 714:                         l_minuendCurY    = l_intersectY;
 715:                         l_subtrahendCurX = l_intersectX;
 716:                         l_subtrahendCurY = l_intersectY;
 717:                     }
 718:                 }
 719:             }
 720: 
 721:             if (b_intersect) {
 722:                 // create the polygon
 723:                 // add the minuend's points to polygon
 724:                 l_polygonXs.addAll(l_minuendXs);
 725:                 l_polygonYs.addAll(l_minuendYs);
 726: 
 727:                 // add intersection point to the polygon
 728:                 l_polygonXs.add(l_intersectX);
 729:                 l_polygonYs.add(l_intersectY);
 730: 
 731:                 // add the subtrahend's points to the polygon in reverse
 732:                 Collections.reverse(l_subtrahendXs);
 733:                 Collections.reverse(l_subtrahendYs);
 734:                 l_polygonXs.addAll(l_subtrahendXs);
 735:                 l_polygonYs.addAll(l_subtrahendYs);
 736: 
 737:                 // create an actual polygon
 738:                 b_positive = (l_subtrahendMaxY <= l_minuendMaxY) 
 739:                         && (l_subtrahendMinY <= l_minuendMinY);
 740:                 createPolygon(x_graphics, x_dataArea, x_plot, x_domainAxis, 
 741:                         x_rangeAxis, b_positive, l_polygonXs, l_polygonYs);
 742: 
 743:                 // clear the point vectors
 744:                 l_minuendXs.clear();
 745:                 l_minuendYs.clear();
 746:                 l_subtrahendXs.clear();
 747:                 l_subtrahendYs.clear();
 748:                 l_polygonXs.clear();
 749:                 l_polygonYs.clear();
 750: 
 751:                 // set the maxY and minY values to intersect y-value
 752:                 double l_y       = l_intersectY.doubleValue();
 753:                 l_minuendMaxY    = l_y;
 754:                 l_subtrahendMaxY = l_y;
 755:                 l_minuendMinY    = l_y;
 756:                 l_subtrahendMinY = l_y;
 757: 
 758:                 // add interection point to new polygon
 759:                 l_polygonXs.add(l_intersectX);
 760:                 l_polygonYs.add(l_intersectY);
 761:             }
 762: 
 763:             // advance the minuend if needed
 764:             if (l_x2 <= l_x4) {
 765:                 l_minuendItem++;
 766:                 b_minuendAdvanced = true;
 767:             }
 768:             else {
 769:                 b_minuendAdvanced = false;
 770:             }
 771: 
 772:             // advance the subtrahend if needed
 773:             if (l_x4 <= l_x2) {
 774:                 l_subtrahendItem++;
 775:                 b_subtrahendAdvanced = true;
 776:             }
 777:             else {
 778:                 b_subtrahendAdvanced = false;
 779:             }
 780: 
 781:             b_minuendDone    = (l_minuendItem == (l_minuendItemCount - 1));
 782:             b_subtrahendDone = (l_subtrahendItem == (l_subtrahendItemCount 
 783:                     - 1));
 784:         }
 785: 
 786:         // check if the final polygon needs to be clipped
 787:         if (b_minuendDone && (l_x3 < l_x2) && (l_x2 < l_x4)) {
 788:             // project onto subtrahend
 789:             double l_slope    = (l_y4 - l_y3) / (l_x4 - l_x3);
 790:             l_subtrahendNextX = l_minuendNextX;
 791:             l_subtrahendNextY = new Double((l_slope * l_x2) 
 792:                     + (l_y3 - (l_slope * l_x3)));
 793:         }
 794: 
 795:         if (b_subtrahendDone && (l_x1 < l_x4) && (l_x4 < l_x2)) {
 796:             // project onto minuend
 797:             double l_slope = (l_y2 - l_y1) / (l_x2 - l_x1);
 798:             l_minuendNextX = l_subtrahendNextX;
 799:             l_minuendNextY = new Double((l_slope * l_x4) 
 800:                     + (l_y1 - (l_slope * l_x1)));
 801:         }
 802: 
 803:         // consider last point of minuend and subtrahend for determining 
 804:         // positivity
 805:         l_minuendMaxY    = Math.max(l_minuendMaxY, 
 806:                 l_minuendNextY.doubleValue());
 807:         l_subtrahendMaxY = Math.max(l_subtrahendMaxY, 
 808:                 l_subtrahendNextY.doubleValue());
 809:         l_minuendMinY    = Math.min(l_minuendMinY, 
 810:                 l_minuendNextY.doubleValue());
 811:         l_subtrahendMinY = Math.min(l_subtrahendMinY, 
 812:                 l_subtrahendNextY.doubleValue());
 813: 
 814:         // add the last point of the minuned and subtrahend
 815:         l_minuendXs.add(l_minuendNextX);
 816:         l_minuendYs.add(l_minuendNextY);
 817:         l_subtrahendXs.add(l_subtrahendNextX);
 818:         l_subtrahendYs.add(l_subtrahendNextY);
 819: 
 820:         // create the polygon
 821:         // add the minuend's points to polygon
 822:         l_polygonXs.addAll(l_minuendXs);
 823:         l_polygonYs.addAll(l_minuendYs);
 824: 
 825:         // add the subtrahend's points to the polygon in reverse
 826:         Collections.reverse(l_subtrahendXs);
 827:         Collections.reverse(l_subtrahendYs);
 828:         l_polygonXs.addAll(l_subtrahendXs);
 829:         l_polygonYs.addAll(l_subtrahendYs);
 830: 
 831:         // create an actual polygon
 832:         b_positive = (l_subtrahendMaxY <= l_minuendMaxY) 
 833:                 && (l_subtrahendMinY <= l_minuendMinY);
 834:         createPolygon(x_graphics, x_dataArea, x_plot, x_domainAxis, 
 835:                 x_rangeAxis, b_positive, l_polygonXs, l_polygonYs);
 836:     }
 837: 
 838:     /**
 839:      * Draws the visual representation of a single data item, second pass.  In 
 840:      * the second pass, the renderer draws the lines and shapes for the 
 841:      * individual points in the two series.
 842:      *
 843:      * @param x_graphics  the graphics device.
 844:      * @param x_dataArea  the area within which the data is being drawn.
 845:      * @param x_info  collects information about the drawing.
 846:      * @param x_plot  the plot (can be used to obtain standard color 
 847:      *         information etc).
 848:      * @param x_domainAxis  the domain (horizontal) axis.
 849:      * @param x_rangeAxis  the range (vertical) axis.
 850:      * @param x_dataset  the dataset.
 851:      * @param x_series  the series index (zero-based).
 852:      * @param x_item  the item index (zero-based).
 853:      * @param x_crosshairState  crosshair information for the plot 
 854:      *                          (<code>null</code> permitted).
 855:      */
 856:     protected void drawItemPass1(Graphics2D x_graphics,
 857:                                  Rectangle2D x_dataArea,
 858:                                  PlotRenderingInfo x_info,
 859:                                  XYPlot x_plot,
 860:                                  ValueAxis x_domainAxis,
 861:                                  ValueAxis x_rangeAxis,
 862:                                  XYDataset x_dataset,
 863:                                  int x_series,
 864:                                  int x_item,
 865:                                  CrosshairState x_crosshairState) {
 866: 
 867:         Shape l_entityArea = null;
 868:         EntityCollection l_entities = null;
 869:         if (null != x_info) {
 870:             l_entities = x_info.getOwner().getEntityCollection();
 871:         }
 872: 
 873:         Paint l_seriesPaint   = getItemPaint(x_series, x_item);
 874:         Stroke l_seriesStroke = getItemStroke(x_series, x_item);
 875:         x_graphics.setPaint(l_seriesPaint);
 876:         x_graphics.setStroke(l_seriesStroke);
 877: 
 878:         PlotOrientation l_orientation      = x_plot.getOrientation();
 879:         RectangleEdge l_domainAxisLocation = x_plot.getDomainAxisEdge();
 880:         RectangleEdge l_rangeAxisLocation  = x_plot.getRangeAxisEdge();
 881: 
 882:         double l_x0 = x_dataset.getXValue(x_series, x_item);
 883:         double l_y0 = x_dataset.getYValue(x_series, x_item);
 884:         double l_x1 = x_domainAxis.valueToJava2D(l_x0, x_dataArea, 
 885:                 l_domainAxisLocation);
 886:         double l_y1 = x_rangeAxis.valueToJava2D(l_y0, x_dataArea, 
 887:                 l_rangeAxisLocation);
 888: 
 889:         if (getShapesVisible()) {
 890:             Shape l_shape = getItemShape(x_series, x_item);
 891:             if (l_orientation == PlotOrientation.HORIZONTAL) {
 892:                 l_shape = ShapeUtilities.createTranslatedShape(l_shape, 
 893:                         l_y1, l_x1);
 894:             }
 895:             else {
 896:                 l_shape = ShapeUtilities.createTranslatedShape(l_shape, 
 897:                         l_x1, l_y1);
 898:             }
 899:             if (l_shape.intersects(x_dataArea)) {
 900:                 x_graphics.setPaint(getItemPaint(x_series, x_item));
 901:                 x_graphics.fill(l_shape);
 902:             }
 903:             l_entityArea = l_shape;
 904:         }
 905: 
 906:         // add an entity for the item...
 907:         if (null != l_entities) {
 908:             if (null == l_entityArea) {
 909:                 l_entityArea = new Rectangle2D.Double((l_x1 - 2), (l_y1 - 2), 
 910:                         4, 4);
 911:             }
 912:             String l_tip = null;
 913:             XYToolTipGenerator l_tipGenerator = getToolTipGenerator(x_series, 
 914:                     x_item);
 915:             if (null != l_tipGenerator) {
 916:                 l_tip = l_tipGenerator.generateToolTip(x_dataset, x_series, 
 917:                         x_item);
 918:             }
 919:             String l_url = null;
 920:             XYURLGenerator l_urlGenerator = getURLGenerator();
 921:             if (null != l_urlGenerator) {
 922:                 l_url = l_urlGenerator.generateURL(x_dataset, x_series, 
 923:                         x_item);
 924:             }
 925:             XYItemEntity l_entity = new XYItemEntity(l_entityArea, x_dataset, 
 926:                     x_series, x_item, l_tip, l_url);
 927:             l_entities.add(l_entity);
 928:         }
 929: 
 930:         // draw the item label if there is one...
 931:         if (isItemLabelVisible(x_series, x_item)) {
 932:             drawItemLabel(x_graphics, l_orientation, x_dataset, x_series,
 933:                           x_item, l_x1, l_y1, (l_y1 < 0.0));
 934:         }
 935: 
 936:         int l_domainAxisIndex = x_plot.getDomainAxisIndex(x_domainAxis);
 937:         int l_rangeAxisIndex  = x_plot.getRangeAxisIndex(x_rangeAxis);
 938:         updateCrosshairValues(x_crosshairState, l_x0, l_y0, l_domainAxisIndex,
 939:                               l_rangeAxisIndex, l_x1, l_y1, l_orientation);
 940: 
 941:         if (0 == x_item) {
 942:             return;
 943:         }
 944: 
 945:         double l_x2 = x_domainAxis.valueToJava2D(x_dataset.getXValue(x_series, 
 946:                 (x_item - 1)), x_dataArea, l_domainAxisLocation);
 947:         double l_y2 = x_rangeAxis.valueToJava2D(x_dataset.getYValue(x_series, 
 948:                 (x_item - 1)), x_dataArea, l_rangeAxisLocation);
 949: 
 950:         Line2D l_line = null;
 951:         if (PlotOrientation.HORIZONTAL == l_orientation) {
 952:             l_line = new Line2D.Double(l_y1, l_x1, l_y2, l_x2);
 953:         }
 954:         else if (PlotOrientation.VERTICAL == l_orientation) {
 955:             l_line = new Line2D.Double(l_x1, l_y1, l_x2, l_y2);
 956:         }
 957:  
 958:         if ((null != l_line) && l_line.intersects(x_dataArea)) {
 959:             x_graphics.setPaint(getItemPaint(x_series, x_item));
 960:             x_graphics.setStroke(getItemStroke(x_series, x_item));
 961:             x_graphics.draw(l_line);
 962:         }
 963:     }
 964: 
 965:     /**
 966:      * Determines if a dataset is degenerate.  A degenerate dataset is a 
 967:      * dataset where either series has less than two (2) points.
 968:      *
 969:      * @param x_dataset  the dataset.
 970:      * @param x_impliedZeroSubtrahend  if false, do not check the subtrahend
 971:      *
 972:      * @return true if the dataset is degenerate.
 973:      */
 974:     private boolean isEitherSeriesDegenerate(XYDataset x_dataset, 
 975:             boolean x_impliedZeroSubtrahend) {
 976: 
 977:         if (x_impliedZeroSubtrahend) {
 978:             return (x_dataset.getItemCount(0) < 2);
 979:         }
 980: 
 981:         return ((x_dataset.getItemCount(0) < 2) 
 982:                 || (x_dataset.getItemCount(1) < 2));
 983:     }
 984: 
 985:     /**
 986:      * Determines if the two (2) series are disjoint.
 987:      * Disjoint series do not overlap in the domain space.
 988:      *
 989:      * @param x_dataset  the dataset.
 990:      *
 991:      * @return true if the dataset is degenerate.
 992:      */
 993:     private boolean areSeriesDisjoint(XYDataset x_dataset) {
 994: 
 995:         int l_minuendItemCount = x_dataset.getItemCount(0);
 996:         double l_minuendFirst  = x_dataset.getXValue(0, 0);
 997:         double l_minuendLast   = x_dataset.getXValue(0, l_minuendItemCount - 1);
 998: 
 999:         int l_subtrahendItemCount = x_dataset.getItemCount(1);
1000:         double l_subtrahendFirst  = x_dataset.getXValue(1, 0);
1001:         double l_subtrahendLast   = x_dataset.getXValue(1, 
1002:                 l_subtrahendItemCount - 1);
1003: 
1004:         return ((l_minuendLast < l_subtrahendFirst) 
1005:                 || (l_subtrahendLast < l_minuendFirst));
1006:     }
1007: 
1008:     /**
1009:      * Draws the visual representation of a polygon
1010:      *
1011:      * @param x_graphics  the graphics device.
1012:      * @param x_dataArea  the area within which the data is being drawn.
1013:      * @param x_plot  the plot (can be used to obtain standard color
1014:      *                information etc).
1015:      * @param x_domainAxis  the domain (horizontal) axis.
1016:      * @param x_rangeAxis  the range (vertical) axis.
1017:      * @param x_positive  indicates if the polygon is positive (true) or 
1018:      *                    negative (false).
1019:      * @param x_xValues  a linked list of the x values (expects values to be 
1020:      *                   of type Double).
1021:      * @param x_yValues  a linked list of the y values (expects values to be 
1022:      *                   of type Double).
1023:      */
1024:     private void createPolygon (Graphics2D x_graphics,
1025:                                 Rectangle2D x_dataArea,
1026:                                 XYPlot x_plot,
1027:                                 ValueAxis x_domainAxis,
1028:                                 ValueAxis x_rangeAxis,
1029:                                 boolean x_positive,
1030:                                 LinkedList x_xValues,
1031:                                 LinkedList x_yValues) {
1032: 
1033:         PlotOrientation l_orientation      = x_plot.getOrientation();
1034:         RectangleEdge l_domainAxisLocation = x_plot.getDomainAxisEdge();
1035:         RectangleEdge l_rangeAxisLocation  = x_plot.getRangeAxisEdge();
1036: 
1037:         Object[] l_xValues = x_xValues.toArray();
1038:         Object[] l_yValues = x_yValues.toArray();
1039: 
1040:         GeneralPath l_path = new GeneralPath();
1041: 
1042:         if (PlotOrientation.VERTICAL == l_orientation) {
1043:             double l_x = x_domainAxis.valueToJava2D((
1044:                     (Double) l_xValues[0]).doubleValue(), x_dataArea, 
1045:                     l_domainAxisLocation);
1046:             if (this.roundXCoordinates) {
1047:                 l_x = Math.rint(l_x);
1048:             }
1049: 
1050:             double l_y = x_rangeAxis.valueToJava2D((
1051:                     (Double) l_yValues[0]).doubleValue(), x_dataArea, 
1052:                     l_rangeAxisLocation);
1053: 
1054:             l_path.moveTo((float) l_x, (float) l_y);
1055:             for (int i = 1; i < l_xValues.length; i++) {
1056:                 l_x = x_domainAxis.valueToJava2D((
1057:                         (Double) l_xValues[i]).doubleValue(), x_dataArea, 
1058:                         l_domainAxisLocation);
1059:                 if (this.roundXCoordinates) {
1060:                     l_x = Math.rint(l_x);
1061:                 }
1062: 
1063:                 l_y = x_rangeAxis.valueToJava2D((
1064:                         (Double) l_yValues[i]).doubleValue(), x_dataArea, 
1065:                         l_rangeAxisLocation);
1066:                 l_path.lineTo((float) l_x, (float) l_y);
1067:             }
1068:             l_path.closePath();
1069:         }
1070:         else {
1071:             double l_x = x_domainAxis.valueToJava2D((
1072:                     (Double) l_xValues[0]).doubleValue(), x_dataArea, 
1073:                     l_domainAxisLocation);
1074:             if (this.roundXCoordinates) {
1075:                 l_x = Math.rint(l_x);
1076:             }
1077: 
1078:             double l_y = x_rangeAxis.valueToJava2D((
1079:                     (Double) l_yValues[0]).doubleValue(), x_dataArea, 
1080:                     l_rangeAxisLocation);
1081: 
1082:             l_path.moveTo((float) l_y, (float) l_x);
1083:             for (int i = 1; i < l_xValues.length; i++) {
1084:                 l_x = x_domainAxis.valueToJava2D((
1085:                         (Double) l_xValues[i]).doubleValue(), x_dataArea, 
1086:                         l_domainAxisLocation);
1087:                 if (this.roundXCoordinates) {
1088:                     l_x = Math.rint(l_x);
1089:                 }
1090: 
1091:                 l_y = x_rangeAxis.valueToJava2D((
1092:                         (Double) l_yValues[i]).doubleValue(), x_dataArea, 
1093:                         l_rangeAxisLocation);
1094:                 l_path.lineTo((float) l_y, (float) l_x);
1095:             }
1096:             l_path.closePath();
1097:         }
1098: 
1099:         if (l_path.intersects(x_dataArea)) {
1100:             x_graphics.setPaint(x_positive ? getPositivePaint() 
1101:                     : getNegativePaint());
1102:             x_graphics.fill(l_path);
1103:         }
1104:     }
1105: 
1106:     /**
1107:      * Returns a default legend item for the specified series.  Subclasses 
1108:      * should override this method to generate customised items.
1109:      *
1110:      * @param datasetIndex  the dataset index (zero-based).
1111:      * @param series  the series index (zero-based).
1112:      *
1113:      * @return A legend item for the series.
1114:      */
1115:     public LegendItem getLegendItem(int datasetIndex, int series) {
1116:         LegendItem result = null;
1117:         XYPlot p = getPlot();
1118:         if (p != null) {
1119:             XYDataset dataset = p.getDataset(datasetIndex);
1120:             if (dataset != null) {
1121:                 if (getItemVisible(series, 0)) {
1122:                     String label = getLegendItemLabelGenerator().generateLabel(
1123:                             dataset, series);
1124:                     String description = label;
1125:                     String toolTipText = null;
1126:                     if (getLegendItemToolTipGenerator() != null) {
1127:                         toolTipText 
1128:                             = getLegendItemToolTipGenerator().generateLabel(
1129:                                     dataset, series);
1130:                     }
1131:                     String urlText = null;
1132:                     if (getLegendItemURLGenerator() != null) {
1133:                         urlText = getLegendItemURLGenerator().generateLabel(
1134:                                 dataset, series);
1135:                     }
1136:                     Paint paint = lookupSeriesPaint(series);
1137:                     Stroke stroke = lookupSeriesStroke(series);
1138:                     // TODO:  the following hard-coded line needs generalising
1139:                     Line2D line = new Line2D.Double(-7.0, 0.0, 7.0, 0.0);
1140:                     result = new LegendItem(label, description, 
1141:                             toolTipText, urlText, line, stroke, paint);
1142:                     result.setDataset(dataset);
1143:                     result.setDatasetIndex(datasetIndex);
1144:                     result.setSeriesKey(dataset.getSeriesKey(series));
1145:                     result.setSeriesIndex(series);
1146:                 }
1147:             }
1148: 
1149:         }
1150: 
1151:         return result;
1152: 
1153:     }
1154: 
1155:     /**
1156:      * Tests this renderer for equality with an arbitrary object.
1157:      * 
1158:      * @param obj  the object (<code>null</code> permitted).
1159:      * 
1160:      * @return A boolean.
1161:      */    
1162:     public boolean equals(Object obj) {
1163:         if (obj == this) {
1164:             return true;   
1165:         }
1166:         if (!(obj instanceof XYDifferenceRenderer)) {
1167:             return false;   
1168:         }
1169:         if (!super.equals(obj)) {
1170:             return false;   
1171:         }
1172:         XYDifferenceRenderer that = (XYDifferenceRenderer) obj;
1173:         if (!PaintUtilities.equal(this.positivePaint, that.positivePaint)) {
1174:             return false;   
1175:         }
1176:         if (!PaintUtilities.equal(this.negativePaint, that.negativePaint)) {
1177:             return false;   
1178:         }
1179:         if (this.shapesVisible != that.shapesVisible) {
1180:             return false;   
1181:         }
1182:         if (!ShapeUtilities.equal(this.legendLine, that.legendLine)) {
1183:             return false;   
1184:         }
1185:         if (this.roundXCoordinates != that.roundXCoordinates) {
1186:             return false;
1187:         }
1188:         return true;
1189:     }
1190:     
1191:     /**
1192:      * Returns a clone of the renderer.
1193:      * 
1194:      * @return A clone.
1195:      * 
1196:      * @throws CloneNotSupportedException  if the renderer cannot be cloned.
1197:      */
1198:     public Object clone() throws CloneNotSupportedException {
1199:         XYDifferenceRenderer clone = (XYDifferenceRenderer) super.clone();
1200:         clone.legendLine = ShapeUtilities.clone(this.legendLine);
1201:         return clone;
1202:     }
1203: 
1204:     /**
1205:      * Provides serialization support.
1206:      *
1207:      * @param stream  the output stream.
1208:      *
1209:      * @throws IOException  if there is an I/O error.
1210:      */
1211:     private void writeObject(ObjectOutputStream stream) throws IOException {
1212:         stream.defaultWriteObject();
1213:         SerialUtilities.writePaint(this.positivePaint, stream);
1214:         SerialUtilities.writePaint(this.negativePaint, stream);
1215:         SerialUtilities.writeShape(this.legendLine, stream);
1216:     }
1217: 
1218:     /**
1219:      * Provides serialization support.
1220:      *
1221:      * @param stream  the input stream.
1222:      *
1223:      * @throws IOException  if there is an I/O error.
1224:      * @throws ClassNotFoundException  if there is a classpath problem.
1225:      */
1226:     private void readObject(ObjectInputStream stream) 
1227:         throws IOException, ClassNotFoundException {
1228:         stream.defaultReadObject();
1229:         this.positivePaint = SerialUtilities.readPaint(stream);
1230:         this.negativePaint = SerialUtilities.readPaint(stream);
1231:         this.legendLine = SerialUtilities.readShape(stream);
1232:     }
1233: 
1234: }