Source for org.jfree.data.xy.IntervalXYDelegate

   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:  * IntervalXYDelegate.java
  29:  * -----------------------
  30:  * (C) Copyright 2004, 2005, 2007, by Andreas Schroeder and Contributors.
  31:  *
  32:  * Original Author:  Andreas Schroeder;
  33:  * Contributor(s):   David Gilbert (for Object Refinery Limited);
  34:  *
  35:  * Changes
  36:  * -------
  37:  * 31-Mar-2004 : Version 1 (AS);
  38:  * 15-Jul-2004 : Switched getX() with getXValue() and getY() with 
  39:  *               getYValue() (DG);
  40:  * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.xy (DG);
  41:  * 04-Nov-2004 : Added argument check for setIntervalWidth() method (DG);
  42:  * 17-Nov-2004 : New methods to reflect changes in DomainInfo (DG);
  43:  * 11-Jan-2005 : Removed deprecated methods in preparation for the 1.0.0 
  44:  *               release (DG);
  45:  * 21-Feb-2005 : Made public and added equals() method (DG);
  46:  * 06-Oct-2005 : Implemented DatasetChangeListener to recalculate 
  47:  *               autoIntervalWidth (DG);
  48:  * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG);
  49:  *   
  50:  */
  51: 
  52: package org.jfree.data.xy;
  53: 
  54: import java.io.Serializable;
  55: 
  56: import org.jfree.data.DomainInfo;
  57: import org.jfree.data.Range;
  58: import org.jfree.data.RangeInfo;
  59: import org.jfree.data.general.DatasetChangeEvent;
  60: import org.jfree.data.general.DatasetChangeListener;
  61: import org.jfree.data.general.DatasetUtilities;
  62: import org.jfree.util.PublicCloneable;
  63: 
  64: /**
  65:  * A delegate that handles the specification or automatic calculation of the
  66:  * interval surrounding the x-values in a dataset.  This is used to extend
  67:  * a regular {@link XYDataset} to support the {@link IntervalXYDataset} 
  68:  * interface.
  69:  * <p> 
  70:  * The decorator pattern was not used because of the several possibly 
  71:  * implemented interfaces of the decorated instance (e.g. 
  72:  * {@link TableXYDataset}, {@link RangeInfo}, {@link DomainInfo} etc.).
  73:  * <p>
  74:  * The width can be set manually or calculated automatically. The switch
  75:  * autoWidth allows to determine which behavior is used. The auto width 
  76:  * calculation tries to find the smallest gap between two x-values in the
  77:  * dataset.  If there is only one item in the series, the auto width 
  78:  * calculation fails and falls back on the manually set interval width (which 
  79:  * is itself defaulted to 1.0). 
  80:  */
  81: public class IntervalXYDelegate implements DatasetChangeListener,
  82:                                            DomainInfo, Serializable, 
  83:                                            Cloneable, PublicCloneable {
  84:     
  85:     /** For serialization. */
  86:     private static final long serialVersionUID = -685166711639592857L;
  87:     
  88:     /**
  89:      * The dataset to enhance. 
  90:      */
  91:     private XYDataset dataset;
  92: 
  93:     /**
  94:      * A flag to indicate whether the width should be calculated automatically.
  95:      */
  96:     private boolean autoWidth;
  97:     
  98:     /**
  99:      * A value between 0.0 and 1.0 that indicates the position of the x-value
 100:      * within the interval.
 101:      */
 102:     private double intervalPositionFactor; 
 103:     
 104:     /**
 105:      * The fixed interval width (defaults to 1.0).
 106:      */
 107:     private double fixedIntervalWidth;
 108:     
 109:     /**
 110:      * The automatically calculated interval width.
 111:      */
 112:     private double autoIntervalWidth;
 113:     
 114:     /**
 115:      * Creates a new delegate that.
 116:      * 
 117:      * @param dataset  the underlying dataset (<code>null</code> not permitted).
 118:      */
 119:     public IntervalXYDelegate(XYDataset dataset) {
 120:         this(dataset, true);
 121:     }
 122:     
 123:     /**
 124:      * Creates a new delegate for the specified dataset.
 125:      * 
 126:      * @param dataset  the underlying dataset (<code>null</code> not permitted).
 127:      * @param autoWidth  a flag that controls whether the interval width is 
 128:      *                   calculated automatically.
 129:      */
 130:     public IntervalXYDelegate(XYDataset dataset, boolean autoWidth) {
 131:         if (dataset == null) {
 132:             throw new IllegalArgumentException("Null 'dataset' argument.");
 133:         }
 134:         this.dataset = dataset;
 135:         this.autoWidth = autoWidth;
 136:         this.intervalPositionFactor = 0.5;
 137:         this.autoIntervalWidth = Double.POSITIVE_INFINITY; 
 138:         this.fixedIntervalWidth = 1.0;
 139:     }
 140:     
 141:     /**
 142:      * Returns <code>true</code> if the interval width is automatically 
 143:      * calculated, and <code>false</code> otherwise.
 144:      * 
 145:      * @return A boolean.
 146:      */
 147:     public boolean isAutoWidth() {
 148:         return this.autoWidth;
 149:     }
 150:     
 151:     /**
 152:      * Sets the flag that indicates whether the interval width is automatically
 153:      * calculated.  If the flag is set to <code>true</code>, the interval is
 154:      * recalculated.
 155:      * <p>
 156:      * Note: recalculating the interval amounts to changing the data values
 157:      * represented by the dataset.  The calling dataset must fire an
 158:      * appropriate {@link DatasetChangeEvent}.
 159:      * 
 160:      * @param b  a boolean.
 161:      */
 162:     public void setAutoWidth(boolean b) {
 163:         this.autoWidth = b;
 164:         if (b) {
 165:             this.autoIntervalWidth = recalculateInterval();
 166:         }
 167:     }
 168:     
 169:     /**
 170:      * Returns the interval position factor.
 171:      * 
 172:      * @return The interval position factor.
 173:      */
 174:     public double getIntervalPositionFactor() {
 175:         return this.intervalPositionFactor;
 176:     }
 177: 
 178:     /**
 179:      * Sets the interval position factor.  This controls how the interval is
 180:      * aligned to the x-value.  For a value of 0.5, the interval is aligned
 181:      * with the x-value in the center.  For a value of 0.0, the interval is
 182:      * aligned with the x-value at the lower end of the interval, and for a 
 183:      * value of 1.0, the interval is aligned with the x-value at the upper
 184:      * end of the interval.
 185:      * 
 186:      * Note that changing the interval position factor amounts to changing the 
 187:      * data values represented by the dataset.  Therefore, the dataset that is 
 188:      * using this delegate is responsible for generating the 
 189:      * appropriate {@link DatasetChangeEvent}.     
 190:      * 
 191:      * @param d  the new interval position factor (in the range 
 192:      *           <code>0.0</code> to <code>1.0</code> inclusive).
 193:      */
 194:     public void setIntervalPositionFactor(double d) {
 195:         if (d < 0.0 || 1.0 < d) {
 196:             throw new IllegalArgumentException(
 197:                     "Argument 'd' outside valid range.");
 198:         }
 199:         this.intervalPositionFactor = d;
 200:     }
 201: 
 202:     /**
 203:      * Returns the fixed interval width.
 204:      * 
 205:      * @return The fixed interval width.
 206:      */
 207:     public double getFixedIntervalWidth() {
 208:         return this.fixedIntervalWidth;
 209:     }
 210:     
 211:     /**
 212:      * Sets the fixed interval width and, as a side effect, sets the
 213:      * <code>autoWidth</code> flag to <code>false</code>.  
 214:      * 
 215:      * Note that changing the interval width amounts to changing the data 
 216:      * values represented by the dataset.  Therefore, the dataset
 217:      * that is using this delegate is responsible for generating the 
 218:      * appropriate {@link DatasetChangeEvent}.
 219:      * 
 220:      * @param w  the width (negative values not permitted).
 221:      */
 222:     public void setFixedIntervalWidth(double w) {
 223:         if (w < 0.0) {
 224:             throw new IllegalArgumentException("Negative 'w' argument.");
 225:         }
 226:         this.fixedIntervalWidth = w;
 227:         this.autoWidth = false;
 228:     }
 229:     
 230:     /**
 231:      * Returns the interval width.  This method will return either the 
 232:      * auto calculated interval width or the manually specified interval
 233:      * width, depending on the {@link #isAutoWidth()} result.
 234:      * 
 235:      * @return The interval width to use.
 236:      */
 237:     public double getIntervalWidth() {
 238:         if (isAutoWidth() && !Double.isInfinite(this.autoIntervalWidth)) {
 239:             // everything is fine: autoWidth is on, and an autoIntervalWidth 
 240:             // was set.
 241:             return this.autoIntervalWidth;
 242:         }
 243:         else {
 244:             // either autoWidth is off or autoIntervalWidth was not set.
 245:             return this.fixedIntervalWidth;
 246:         }
 247:     }
 248: 
 249:     /**
 250:      * Returns the start value of the x-interval for an item within a series.
 251:      * 
 252:      * @param series  the series index.
 253:      * @param item  the item index.
 254:      * 
 255:      * @return The start value of the x-interval (possibly <code>null</code>).
 256:      * 
 257:      * @see #getStartXValue(int, int)
 258:      */
 259:     public Number getStartX(int series, int item) {
 260:         Number startX = null;
 261:         Number x = this.dataset.getX(series, item);
 262:         if (x != null) {
 263:             startX = new Double(x.doubleValue() 
 264:                      - (getIntervalPositionFactor() * getIntervalWidth())); 
 265:         }
 266:         return startX;
 267:     }
 268:     
 269:     /**
 270:      * Returns the start value of the x-interval for an item within a series.
 271:      * 
 272:      * @param series  the series index.
 273:      * @param item  the item index.
 274:      * 
 275:      * @return The start value of the x-interval.
 276:      * 
 277:      * @see #getStartX(int, int)
 278:      */
 279:     public double getStartXValue(int series, int item) {
 280:         return this.dataset.getXValue(series, item) 
 281:                 - getIntervalPositionFactor() * getIntervalWidth();
 282:     }
 283:     
 284:     /**
 285:      * Returns the end value of the x-interval for an item within a series.
 286:      * 
 287:      * @param series  the series index.
 288:      * @param item  the item index.
 289:      * 
 290:      * @return The end value of the x-interval (possibly <code>null</code>).
 291:      * 
 292:      * @see #getEndXValue(int, int)
 293:      */
 294:     public Number getEndX(int series, int item) {
 295:         Number endX = null;
 296:         Number x = this.dataset.getX(series, item);
 297:         if (x != null) {
 298:             endX = new Double(x.doubleValue() 
 299:                 + ((1.0 - getIntervalPositionFactor()) * getIntervalWidth())); 
 300:         }
 301:         return endX;
 302:     }
 303: 
 304:     /**
 305:      * Returns the end value of the x-interval for an item within a series.
 306:      * 
 307:      * @param series  the series index.
 308:      * @param item  the item index.
 309:      * 
 310:      * @return The end value of the x-interval.
 311:      * 
 312:      * @see #getEndX(int, int)
 313:      */
 314:     public double getEndXValue(int series, int item) {
 315:         return this.dataset.getXValue(series, item) 
 316:                 + (1.0 - getIntervalPositionFactor()) * getIntervalWidth();
 317:     }
 318:     
 319:     /**
 320:      * Returns the minimum x-value in the dataset.
 321:      *
 322:      * @param includeInterval  a flag that determines whether or not the
 323:      *                         x-interval is taken into account.
 324:      * 
 325:      * @return The minimum value.
 326:      */
 327:     public double getDomainLowerBound(boolean includeInterval) {
 328:         double result = Double.NaN;
 329:         Range r = getDomainBounds(includeInterval);
 330:         if (r != null) {
 331:             result = r.getLowerBound();
 332:         }
 333:         return result;
 334:     }
 335: 
 336:     /**
 337:      * Returns the maximum x-value in the dataset.
 338:      *
 339:      * @param includeInterval  a flag that determines whether or not the
 340:      *                         x-interval is taken into account.
 341:      * 
 342:      * @return The maximum value.
 343:      */
 344:     public double getDomainUpperBound(boolean includeInterval) {
 345:         double result = Double.NaN;
 346:         Range r = getDomainBounds(includeInterval);
 347:         if (r != null) {
 348:             result = r.getUpperBound();
 349:         }
 350:         return result;
 351:     }
 352: 
 353:     /**
 354:      * Returns the range of the values in the dataset's domain, including
 355:      * or excluding the interval around each x-value as specified.
 356:      *
 357:      * @param includeInterval  a flag that determines whether or not the 
 358:      *                         x-interval should be taken into account.
 359:      * 
 360:      * @return The range.
 361:      */
 362:     public Range getDomainBounds(boolean includeInterval) {
 363:         // first get the range without the interval, then expand it for the
 364:         // interval width
 365:         Range range = DatasetUtilities.findDomainBounds(this.dataset, false);
 366:         if (includeInterval && range != null) {
 367:             double lowerAdj = getIntervalWidth() * getIntervalPositionFactor();
 368:             double upperAdj = getIntervalWidth() - lowerAdj;
 369:             range = new Range(range.getLowerBound() - lowerAdj, 
 370:                 range.getUpperBound() + upperAdj);
 371:         }
 372:         return range;
 373:     }
 374:     
 375:     /**
 376:      * Handles events from the dataset by recalculating the interval if 
 377:      * necessary.
 378:      * 
 379:      * @param e  the event.
 380:      */    
 381:     public void datasetChanged(DatasetChangeEvent e) {
 382:         // TODO: by coding the event with some information about what changed
 383:         // in the dataset, we could make the recalculation of the interval
 384:         // more efficient in some cases...
 385:         if (this.autoWidth) {
 386:             this.autoIntervalWidth = recalculateInterval();
 387:         }
 388:     }
 389:     
 390:     /**
 391:      * Recalculate the minimum width "from scratch".
 392:      * 
 393:      * @return The minimum width.
 394:      */
 395:     private double recalculateInterval() {
 396:         double result = Double.POSITIVE_INFINITY;
 397:         int seriesCount = this.dataset.getSeriesCount();
 398:         for (int series = 0; series < seriesCount; series++) {
 399:             result = Math.min(result, calculateIntervalForSeries(series));
 400:         }
 401:         return result;
 402:     }
 403:     
 404:     /**
 405:      * Calculates the interval width for a given series.
 406:      *  
 407:      * @param series  the series index.
 408:      * 
 409:      * @return The interval width.
 410:      */
 411:     private double calculateIntervalForSeries(int series) {
 412:         double result = Double.POSITIVE_INFINITY;
 413:         int itemCount = this.dataset.getItemCount(series);
 414:         if (itemCount > 1) {
 415:             double prev = this.dataset.getXValue(series, 0);
 416:             for (int item = 1; item < itemCount; item++) {
 417:                 double x = this.dataset.getXValue(series, item);
 418:                 result = Math.min(result, x - prev);
 419:                 prev = x;
 420:             }
 421:         }
 422:         return result;
 423:     }
 424:     
 425:     /**
 426:      * Tests the delegate for equality with an arbitrary object.
 427:      * 
 428:      * @param obj  the object (<code>null</code> permitted).
 429:      * 
 430:      * @return A boolean.
 431:      */
 432:     public boolean equals(Object obj) {
 433:         if (obj == this) {
 434:             return true;   
 435:         }
 436:         if (!(obj instanceof IntervalXYDelegate)) {
 437:             return false;   
 438:         }
 439:         IntervalXYDelegate that = (IntervalXYDelegate) obj;
 440:         if (this.autoWidth != that.autoWidth) {
 441:             return false;   
 442:         }
 443:         if (this.intervalPositionFactor != that.intervalPositionFactor) {
 444:             return false;   
 445:         }
 446:         if (this.fixedIntervalWidth != that.fixedIntervalWidth) {
 447:             return false;   
 448:         }
 449:         return true;
 450:     }
 451:     
 452:     /**
 453:      * @return A clone of this delegate.
 454:      * 
 455:      * @throws CloneNotSupportedException if the object cannot be cloned.
 456:      */
 457:     public Object clone() throws CloneNotSupportedException {
 458:         return super.clone();
 459:     }
 460:     
 461: }