001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it
010     * under the terms of the GNU Lesser General Public License as published by
011     * the Free Software Foundation; either version 2.1 of the License, or
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022     * USA.
023     *
024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025     * in the United States and other countries.]
026     *
027     * -------------------------
028     * CombinedDomainXYPlot.java
029     * -------------------------
030     * (C) Copyright 2001-2008, by Bill Kelemen and Contributors.
031     *
032     * Original Author:  Bill Kelemen;
033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
034     *                   Anthony Boulestreau;
035     *                   David Basten;
036     *                   Kevin Frechette (for ISTI);
037     *                   Nicolas Brodu;
038     *                   Petr Kubanek (bug 1606205);
039     *
040     * Changes:
041     * --------
042     * 06-Dec-2001 : Version 1 (BK);
043     * 12-Dec-2001 : Removed unnecessary 'throws' clause from constructor (DG);
044     * 18-Dec-2001 : Added plotArea attribute and get/set methods (BK);
045     * 22-Dec-2001 : Fixed bug in chartChanged with multiple combinations of
046     *               CombinedPlots (BK);
047     * 08-Jan-2002 : Moved to new package com.jrefinery.chart.combination (DG);
048     * 25-Feb-2002 : Updated import statements (DG);
049     * 28-Feb-2002 : Readded "this.plotArea = plotArea" that was deleted from
050     *               draw() method (BK);
051     * 26-Mar-2002 : Added an empty zoom method (this method needs to be written so
052     *               that combined plots will support zooming (DG);
053     * 29-Mar-2002 : Changed the method createCombinedAxis adding the creation of
054     *               OverlaidSymbolicAxis and CombinedSymbolicAxis(AB);
055     * 23-Apr-2002 : Renamed CombinedPlot-->MultiXYPlot, and simplified the
056     *               structure (DG);
057     * 23-May-2002 : Renamed (again) MultiXYPlot-->CombinedXYPlot (DG);
058     * 19-Jun-2002 : Added get/setGap() methods suggested by David Basten (DG);
059     * 25-Jun-2002 : Removed redundant imports (DG);
060     * 16-Jul-2002 : Draws shared axis after subplots (to fix missing gridlines),
061     *               added overrides of 'setSeriesPaint()' and 'setXYItemRenderer()'
062     *               that pass changes down to subplots (KF);
063     * 09-Oct-2002 : Added add(XYPlot) method (DG);
064     * 26-Mar-2003 : Implemented Serializable (DG);
065     * 16-May-2003 : Renamed CombinedXYPlot --> CombinedDomainXYPlot (DG);
066     * 04-Aug-2003 : Removed leftover code that was causing domain axis drawing
067     *               problem (DG);
068     * 08-Aug-2003 : Adjusted totalWeight in remove() method (DG);
069     * 21-Aug-2003 : Implemented Cloneable (DG);
070     * 11-Sep-2003 : Fix cloning support (subplots) (NB);
071     * 15-Sep-2003 : Fixed error in cloning (DG);
072     * 16-Sep-2003 : Changed ChartRenderingInfo --> PlotRenderingInfo (DG);
073     * 17-Sep-2003 : Updated handling of 'clicks' (DG);
074     * 12-Nov-2004 : Implemented the new Zoomable interface (DG);
075     * 25-Nov-2004 : Small update to clone() implementation (DG);
076     * 21-Feb-2005 : The getLegendItems() method now returns the fixed legend
077     *               items if set (DG);
078     * 05-May-2005 : Removed unused draw() method (DG);
079     * ------------- JFREECHART 1.0.x ---------------------------------------------
080     * 23-Aug-2006 : Override setFixedRangeAxisSpace() to update subplots (DG);
081     * 06-Feb-2007 : Fixed bug 1606205, draw shared axis after subplots (DG);
082     * 23-Mar-2007 : Reverted previous patch (bug fix 1606205) (DG);
083     * 17-Apr-2007 : Added null argument checks to findSubplot() (DG);
084     * 27-Nov-2007 : Modified setFixedRangeAxisSpaceForSubplots() so as not to
085     *               trigger change event in subplots (DG);
086     * 28-Jan-2008 : Reset fixed range axis space in subplots for each call to
087     *               draw() (DG);
088     * 27-Mar-2008 : Add documentation for getDataRange() method (DG);
089     * 31-Mar-2008 : Updated getSubplots() to return EMPTY_LIST for null
090     *               subplots, as suggested by Richard West (DG);
091     * 28-Apr-2008 : Fixed zooming problem (see bug 1950037) (DG);
092     * 11-Aug-2008 : Don't store totalWeight of subplots, calculate it as
093     *               required (DG);
094     *
095     */
096    
097    package org.jfree.chart.plot;
098    
099    import java.awt.Graphics2D;
100    import java.awt.geom.Point2D;
101    import java.awt.geom.Rectangle2D;
102    import java.util.Collections;
103    import java.util.Iterator;
104    import java.util.List;
105    
106    import org.jfree.chart.LegendItemCollection;
107    import org.jfree.chart.axis.AxisSpace;
108    import org.jfree.chart.axis.AxisState;
109    import org.jfree.chart.axis.NumberAxis;
110    import org.jfree.chart.axis.ValueAxis;
111    import org.jfree.chart.event.PlotChangeEvent;
112    import org.jfree.chart.event.PlotChangeListener;
113    import org.jfree.chart.renderer.xy.XYItemRenderer;
114    import org.jfree.data.Range;
115    import org.jfree.ui.RectangleEdge;
116    import org.jfree.ui.RectangleInsets;
117    import org.jfree.util.ObjectUtilities;
118    
119    /**
120     * An extension of {@link XYPlot} that contains multiple subplots that share a
121     * common domain axis.
122     */
123    public class CombinedDomainXYPlot extends XYPlot
124            implements PlotChangeListener {
125    
126        /** For serialization. */
127        private static final long serialVersionUID = -7765545541261907383L;
128    
129        /** Storage for the subplot references. */
130        private List subplots;
131    
132        /** The gap between subplots. */
133        private double gap = 5.0;
134    
135        /** Temporary storage for the subplot areas. */
136        private transient Rectangle2D[] subplotAreas;
137        // TODO:  the subplot areas needs to be moved out of the plot into the plot
138        //        state
139    
140        /**
141         * Default constructor.
142         */
143        public CombinedDomainXYPlot() {
144            this(new NumberAxis());
145        }
146    
147        /**
148         * Creates a new combined plot that shares a domain axis among multiple
149         * subplots.
150         *
151         * @param domainAxis  the shared axis.
152         */
153        public CombinedDomainXYPlot(ValueAxis domainAxis) {
154    
155            super(
156                null,        // no data in the parent plot
157                domainAxis,
158                null,        // no range axis
159                null         // no rendereer
160            );
161    
162            this.subplots = new java.util.ArrayList();
163    
164        }
165    
166        /**
167         * Returns a string describing the type of plot.
168         *
169         * @return The type of plot.
170         */
171        public String getPlotType() {
172            return "Combined_Domain_XYPlot";
173        }
174    
175        /**
176         * Sets the orientation for the plot (also changes the orientation for all
177         * the subplots to match).
178         *
179         * @param orientation  the orientation (<code>null</code> not allowed).
180         */
181        public void setOrientation(PlotOrientation orientation) {
182    
183            super.setOrientation(orientation);
184            Iterator iterator = this.subplots.iterator();
185            while (iterator.hasNext()) {
186                XYPlot plot = (XYPlot) iterator.next();
187                plot.setOrientation(orientation);
188            }
189    
190        }
191    
192        /**
193         * Returns a range representing the extent of the data values in this plot
194         * (obtained from the subplots) that will be rendered against the specified
195         * axis.  NOTE: This method is intended for internal JFreeChart use, and
196         * is public only so that code in the axis classes can call it.  Since
197         * only the domain axis is shared between subplots, the JFreeChart code
198         * will only call this method for the domain values (although this is not
199         * checked/enforced).
200         *
201         * @param axis  the axis.
202         *
203         * @return The range (possibly <code>null</code>).
204         */
205        public Range getDataRange(ValueAxis axis) {
206            Range result = null;
207            if (this.subplots != null) {
208                Iterator iterator = this.subplots.iterator();
209                while (iterator.hasNext()) {
210                    XYPlot subplot = (XYPlot) iterator.next();
211                    result = Range.combine(result, subplot.getDataRange(axis));
212                }
213            }
214            return result;
215        }
216    
217        /**
218         * Returns the gap between subplots, measured in Java2D units.
219         *
220         * @return The gap (in Java2D units).
221         */
222        public double getGap() {
223            return this.gap;
224        }
225    
226        /**
227         * Sets the amount of space between subplots and sends a
228         * {@link PlotChangeEvent} to all registered listeners.
229         *
230         * @param gap  the gap between subplots (in Java2D units).
231         */
232        public void setGap(double gap) {
233            this.gap = gap;
234            fireChangeEvent();
235        }
236    
237        /**
238         * Adds a subplot (with a default 'weight' of 1) and sends a
239         * {@link PlotChangeEvent} to all registered listeners.
240         * <P>
241         * The domain axis for the subplot will be set to <code>null</code>.  You
242         * must ensure that the subplot has a non-null range axis.
243         *
244         * @param subplot  the subplot (<code>null</code> not permitted).
245         */
246        public void add(XYPlot subplot) {
247            // defer argument checking
248            add(subplot, 1);
249        }
250    
251        /**
252         * Adds a subplot with the specified weight and sends a
253         * {@link PlotChangeEvent} to all registered listeners.  The weight
254         * determines how much space is allocated to the subplot relative to all
255         * the other subplots.
256         * <P>
257         * The domain axis for the subplot will be set to <code>null</code>.  You
258         * must ensure that the subplot has a non-null range axis.
259         *
260         * @param subplot  the subplot (<code>null</code> not permitted).
261         * @param weight  the weight (must be >= 1).
262         */
263        public void add(XYPlot subplot, int weight) {
264    
265            if (subplot == null) {
266                throw new IllegalArgumentException("Null 'subplot' argument.");
267            }
268            if (weight <= 0) {
269                throw new IllegalArgumentException("Require weight >= 1.");
270            }
271    
272            // store the plot and its weight
273            subplot.setParent(this);
274            subplot.setWeight(weight);
275            subplot.setInsets(new RectangleInsets(0.0, 0.0, 0.0, 0.0), false);
276            subplot.setDomainAxis(null);
277            subplot.addChangeListener(this);
278            this.subplots.add(subplot);
279    
280            ValueAxis axis = getDomainAxis();
281            if (axis != null) {
282                axis.configure();
283            }
284            fireChangeEvent();
285        }
286    
287        /**
288         * Removes a subplot from the combined chart and sends a
289         * {@link PlotChangeEvent} to all registered listeners.
290         *
291         * @param subplot  the subplot (<code>null</code> not permitted).
292         */
293        public void remove(XYPlot subplot) {
294            if (subplot == null) {
295                throw new IllegalArgumentException(" Null 'subplot' argument.");
296            }
297            int position = -1;
298            int size = this.subplots.size();
299            int i = 0;
300            while (position == -1 && i < size) {
301                if (this.subplots.get(i) == subplot) {
302                    position = i;
303                }
304                i++;
305            }
306            if (position != -1) {
307                this.subplots.remove(position);
308                subplot.setParent(null);
309                subplot.removeChangeListener(this);
310                ValueAxis domain = getDomainAxis();
311                if (domain != null) {
312                    domain.configure();
313                }
314                fireChangeEvent();
315            }
316        }
317    
318        /**
319         * Returns the list of subplots.  The returned list may be empty, but is
320         * never <code>null</code>.
321         *
322         * @return An unmodifiable list of subplots.
323         */
324        public List getSubplots() {
325            if (this.subplots != null) {
326                return Collections.unmodifiableList(this.subplots);
327            }
328            else {
329                return Collections.EMPTY_LIST;
330            }
331        }
332    
333        /**
334         * Calculates the axis space required.
335         *
336         * @param g2  the graphics device.
337         * @param plotArea  the plot area.
338         *
339         * @return The space.
340         */
341        protected AxisSpace calculateAxisSpace(Graphics2D g2,
342                                               Rectangle2D plotArea) {
343    
344            AxisSpace space = new AxisSpace();
345            PlotOrientation orientation = getOrientation();
346    
347            // work out the space required by the domain axis...
348            AxisSpace fixed = getFixedDomainAxisSpace();
349            if (fixed != null) {
350                if (orientation == PlotOrientation.HORIZONTAL) {
351                    space.setLeft(fixed.getLeft());
352                    space.setRight(fixed.getRight());
353                }
354                else if (orientation == PlotOrientation.VERTICAL) {
355                    space.setTop(fixed.getTop());
356                    space.setBottom(fixed.getBottom());
357                }
358            }
359            else {
360                ValueAxis xAxis = getDomainAxis();
361                RectangleEdge xEdge = Plot.resolveDomainAxisLocation(
362                        getDomainAxisLocation(), orientation);
363                if (xAxis != null) {
364                    space = xAxis.reserveSpace(g2, this, plotArea, xEdge, space);
365                }
366            }
367    
368            Rectangle2D adjustedPlotArea = space.shrink(plotArea, null);
369    
370            // work out the maximum height or width of the non-shared axes...
371            int n = this.subplots.size();
372            int totalWeight = 0;
373            for (int i = 0; i < n; i++) {
374                XYPlot sub = (XYPlot) this.subplots.get(i);
375                totalWeight += sub.getWeight();
376            }
377            this.subplotAreas = new Rectangle2D[n];
378            double x = adjustedPlotArea.getX();
379            double y = adjustedPlotArea.getY();
380            double usableSize = 0.0;
381            if (orientation == PlotOrientation.HORIZONTAL) {
382                usableSize = adjustedPlotArea.getWidth() - this.gap * (n - 1);
383            }
384            else if (orientation == PlotOrientation.VERTICAL) {
385                usableSize = adjustedPlotArea.getHeight() - this.gap * (n - 1);
386            }
387    
388            for (int i = 0; i < n; i++) {
389                XYPlot plot = (XYPlot) this.subplots.get(i);
390    
391                // calculate sub-plot area
392                if (orientation == PlotOrientation.HORIZONTAL) {
393                    double w = usableSize * plot.getWeight() / totalWeight;
394                    this.subplotAreas[i] = new Rectangle2D.Double(x, y, w,
395                            adjustedPlotArea.getHeight());
396                    x = x + w + this.gap;
397                }
398                else if (orientation == PlotOrientation.VERTICAL) {
399                    double h = usableSize * plot.getWeight() / totalWeight;
400                    this.subplotAreas[i] = new Rectangle2D.Double(x, y,
401                            adjustedPlotArea.getWidth(), h);
402                    y = y + h + this.gap;
403                }
404    
405                AxisSpace subSpace = plot.calculateRangeAxisSpace(g2,
406                        this.subplotAreas[i], null);
407                space.ensureAtLeast(subSpace);
408    
409            }
410    
411            return space;
412        }
413    
414        /**
415         * Draws the plot within the specified area on a graphics device.
416         *
417         * @param g2  the graphics device.
418         * @param area  the plot area (in Java2D space).
419         * @param anchor  an anchor point in Java2D space (<code>null</code>
420         *                permitted).
421         * @param parentState  the state from the parent plot, if there is one
422         *                     (<code>null</code> permitted).
423         * @param info  collects chart drawing information (<code>null</code>
424         *              permitted).
425         */
426        public void draw(Graphics2D g2,
427                         Rectangle2D area,
428                         Point2D anchor,
429                         PlotState parentState,
430                         PlotRenderingInfo info) {
431    
432            // set up info collection...
433            if (info != null) {
434                info.setPlotArea(area);
435            }
436    
437            // adjust the drawing area for plot insets (if any)...
438            RectangleInsets insets = getInsets();
439            insets.trim(area);
440    
441            setFixedRangeAxisSpaceForSubplots(null);
442            AxisSpace space = calculateAxisSpace(g2, area);
443            Rectangle2D dataArea = space.shrink(area, null);
444    
445            // set the width and height of non-shared axis of all sub-plots
446            setFixedRangeAxisSpaceForSubplots(space);
447    
448            // draw the shared axis
449            ValueAxis axis = getDomainAxis();
450            RectangleEdge edge = getDomainAxisEdge();
451            double cursor = RectangleEdge.coordinate(dataArea, edge);
452            AxisState axisState = axis.draw(g2, cursor, area, dataArea, edge, info);
453            if (parentState == null) {
454                parentState = new PlotState();
455            }
456            parentState.getSharedAxisStates().put(axis, axisState);
457    
458            // draw all the subplots
459            for (int i = 0; i < this.subplots.size(); i++) {
460                XYPlot plot = (XYPlot) this.subplots.get(i);
461                PlotRenderingInfo subplotInfo = null;
462                if (info != null) {
463                    subplotInfo = new PlotRenderingInfo(info.getOwner());
464                    info.addSubplotInfo(subplotInfo);
465                }
466                plot.draw(g2, this.subplotAreas[i], anchor, parentState,
467                        subplotInfo);
468            }
469    
470            if (info != null) {
471                info.setDataArea(dataArea);
472            }
473    
474        }
475    
476        /**
477         * Returns a collection of legend items for the plot.
478         *
479         * @return The legend items.
480         */
481        public LegendItemCollection getLegendItems() {
482            LegendItemCollection result = getFixedLegendItems();
483            if (result == null) {
484                result = new LegendItemCollection();
485                if (this.subplots != null) {
486                    Iterator iterator = this.subplots.iterator();
487                    while (iterator.hasNext()) {
488                        XYPlot plot = (XYPlot) iterator.next();
489                        LegendItemCollection more = plot.getLegendItems();
490                        result.addAll(more);
491                    }
492                }
493            }
494            return result;
495        }
496    
497        /**
498         * Multiplies the range on the range axis/axes by the specified factor.
499         *
500         * @param factor  the zoom factor.
501         * @param info  the plot rendering info (<code>null</code> not permitted).
502         * @param source  the source point (<code>null</code> not permitted).
503         */
504        public void zoomRangeAxes(double factor, PlotRenderingInfo info,
505                                  Point2D source) {
506            zoomRangeAxes(factor, info, source, false);
507        }
508    
509        /**
510         * Multiplies the range on the range axis/axes by the specified factor.
511         *
512         * @param factor  the zoom factor.
513         * @param state  the plot state.
514         * @param source  the source point (in Java2D coordinates).
515         * @param useAnchor  use source point as zoom anchor?
516         */
517        public void zoomRangeAxes(double factor, PlotRenderingInfo state,
518                                  Point2D source, boolean useAnchor) {
519            // delegate 'state' and 'source' argument checks...
520            XYPlot subplot = findSubplot(state, source);
521            if (subplot != null) {
522                subplot.zoomRangeAxes(factor, state, source, useAnchor);
523            }
524            else {
525                // if the source point doesn't fall within a subplot, we do the
526                // zoom on all subplots...
527                Iterator iterator = getSubplots().iterator();
528                while (iterator.hasNext()) {
529                    subplot = (XYPlot) iterator.next();
530                    subplot.zoomRangeAxes(factor, state, source, useAnchor);
531                }
532            }
533        }
534    
535        /**
536         * Zooms in on the range axes.
537         *
538         * @param lowerPercent  the lower bound.
539         * @param upperPercent  the upper bound.
540         * @param info  the plot rendering info (<code>null</code> not permitted).
541         * @param source  the source point (<code>null</code> not permitted).
542         */
543        public void zoomRangeAxes(double lowerPercent, double upperPercent,
544                                  PlotRenderingInfo info, Point2D source) {
545            // delegate 'info' and 'source' argument checks...
546            XYPlot subplot = findSubplot(info, source);
547            if (subplot != null) {
548                subplot.zoomRangeAxes(lowerPercent, upperPercent, info, source);
549            }
550            else {
551                // if the source point doesn't fall within a subplot, we do the
552                // zoom on all subplots...
553                Iterator iterator = getSubplots().iterator();
554                while (iterator.hasNext()) {
555                    subplot = (XYPlot) iterator.next();
556                    subplot.zoomRangeAxes(lowerPercent, upperPercent, info, source);
557                }
558            }
559        }
560    
561        /**
562         * Returns the subplot (if any) that contains the (x, y) point (specified
563         * in Java2D space).
564         *
565         * @param info  the chart rendering info (<code>null</code> not permitted).
566         * @param source  the source point (<code>null</code> not permitted).
567         *
568         * @return A subplot (possibly <code>null</code>).
569         */
570        public XYPlot findSubplot(PlotRenderingInfo info, Point2D source) {
571            if (info == null) {
572                throw new IllegalArgumentException("Null 'info' argument.");
573            }
574            if (source == null) {
575                throw new IllegalArgumentException("Null 'source' argument.");
576            }
577            XYPlot result = null;
578            int subplotIndex = info.getSubplotIndex(source);
579            if (subplotIndex >= 0) {
580                result =  (XYPlot) this.subplots.get(subplotIndex);
581            }
582            return result;
583        }
584    
585        /**
586         * Sets the item renderer FOR ALL SUBPLOTS.  Registered listeners are
587         * notified that the plot has been modified.
588         * <P>
589         * Note: usually you will want to set the renderer independently for each
590         * subplot, which is NOT what this method does.
591         *
592         * @param renderer the new renderer.
593         */
594        public void setRenderer(XYItemRenderer renderer) {
595    
596            super.setRenderer(renderer);  // not strictly necessary, since the
597                                          // renderer set for the
598                                          // parent plot is not used
599    
600            Iterator iterator = this.subplots.iterator();
601            while (iterator.hasNext()) {
602                XYPlot plot = (XYPlot) iterator.next();
603                plot.setRenderer(renderer);
604            }
605    
606        }
607    
608        /**
609         * Sets the fixed range axis space and sends a {@link PlotChangeEvent} to
610         * all registered listeners.
611         *
612         * @param space  the space (<code>null</code> permitted).
613         */
614        public void setFixedRangeAxisSpace(AxisSpace space) {
615            super.setFixedRangeAxisSpace(space);
616            setFixedRangeAxisSpaceForSubplots(space);
617            fireChangeEvent();
618        }
619    
620        /**
621         * Sets the size (width or height, depending on the orientation of the
622         * plot) for the domain axis of each subplot.
623         *
624         * @param space  the space.
625         */
626        protected void setFixedRangeAxisSpaceForSubplots(AxisSpace space) {
627            Iterator iterator = this.subplots.iterator();
628            while (iterator.hasNext()) {
629                XYPlot plot = (XYPlot) iterator.next();
630                plot.setFixedRangeAxisSpace(space, false);
631            }
632        }
633    
634        /**
635         * Handles a 'click' on the plot by updating the anchor values.
636         *
637         * @param x  x-coordinate, where the click occured.
638         * @param y  y-coordinate, where the click occured.
639         * @param info  object containing information about the plot dimensions.
640         */
641        public void handleClick(int x, int y, PlotRenderingInfo info) {
642            Rectangle2D dataArea = info.getDataArea();
643            if (dataArea.contains(x, y)) {
644                for (int i = 0; i < this.subplots.size(); i++) {
645                    XYPlot subplot = (XYPlot) this.subplots.get(i);
646                    PlotRenderingInfo subplotInfo = info.getSubplotInfo(i);
647                    subplot.handleClick(x, y, subplotInfo);
648                }
649            }
650        }
651    
652        /**
653         * Receives a {@link PlotChangeEvent} and responds by notifying all
654         * listeners.
655         *
656         * @param event  the event.
657         */
658        public void plotChanged(PlotChangeEvent event) {
659            notifyListeners(event);
660        }
661    
662        /**
663         * Tests this plot for equality with another object.
664         *
665         * @param obj  the other object.
666         *
667         * @return <code>true</code> or <code>false</code>.
668         */
669        public boolean equals(Object obj) {
670            if (obj == this) {
671                return true;
672            }
673            if (!(obj instanceof CombinedDomainXYPlot)) {
674                return false;
675            }
676            CombinedDomainXYPlot that = (CombinedDomainXYPlot) obj;
677            if (this.gap != that.gap) {
678                return false;
679            }
680            if (!ObjectUtilities.equal(this.subplots, that.subplots)) {
681                return false;
682            }
683            return super.equals(obj);
684        }
685    
686        /**
687         * Returns a clone of the annotation.
688         *
689         * @return A clone.
690         *
691         * @throws CloneNotSupportedException  this class will not throw this
692         *         exception, but subclasses (if any) might.
693         */
694        public Object clone() throws CloneNotSupportedException {
695    
696            CombinedDomainXYPlot result = (CombinedDomainXYPlot) super.clone();
697            result.subplots = (List) ObjectUtilities.deepClone(this.subplots);
698            for (Iterator it = result.subplots.iterator(); it.hasNext();) {
699                Plot child = (Plot) it.next();
700                child.setParent(result);
701            }
702    
703            // after setting up all the subplots, the shared domain axis may need
704            // reconfiguring
705            ValueAxis domainAxis = result.getDomainAxis();
706            if (domainAxis != null) {
707                domainAxis.configure();
708            }
709    
710            return result;
711    
712        }
713    
714    }