1 /*
   2  * Copyright (c) 2010, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javafx.scene.chart;
  27 
  28 import java.util.ArrayList;
  29 import java.util.HashMap;
  30 import java.util.List;
  31 import java.util.Map;
  32 
  33 import javafx.animation.FadeTransition;
  34 import javafx.animation.Interpolator;
  35 import javafx.animation.KeyFrame;
  36 import javafx.animation.KeyValue;
  37 import javafx.animation.Timeline;
  38 import javafx.animation.Animation;
  39 import javafx.application.Platform;
  40 import javafx.beans.NamedArg;
  41 import javafx.beans.property.BooleanProperty;
  42 import javafx.beans.property.DoubleProperty;
  43 import javafx.beans.property.ObjectProperty;
  44 import javafx.beans.property.ObjectPropertyBase;
  45 import javafx.beans.property.SimpleDoubleProperty;
  46 import javafx.beans.value.WritableValue;
  47 import javafx.collections.FXCollections;
  48 import javafx.collections.ListChangeListener;
  49 import javafx.collections.ObservableList;
  50 import javafx.scene.AccessibleRole;
  51 import javafx.scene.Node;
  52 import javafx.scene.layout.StackPane;
  53 import javafx.scene.shape.LineTo;
  54 import javafx.scene.shape.MoveTo;
  55 import javafx.scene.shape.Path;
  56 import javafx.scene.shape.PathElement;
  57 import javafx.scene.shape.StrokeLineJoin;
  58 import javafx.util.Duration;
  59 
  60 import com.sun.javafx.charts.Legend;
  61 import com.sun.javafx.charts.Legend.LegendItem;
  62 
  63 import javafx.css.StyleableBooleanProperty;
  64 import javafx.css.CssMetaData;
  65 
  66 import com.sun.javafx.css.converters.BooleanConverter;
  67 
  68 import java.util.*;
  69 
  70 import javafx.css.Styleable;
  71 import javafx.css.StyleableProperty;
  72 
  73 /**
  74  * Line Chart plots a line connecting the data points in a series. The data points
  75  * themselves can be represented by symbols optionally. Line charts are usually used
  76  * to view data trends over time or category. 
  77  * @since JavaFX 2.0
  78  */
  79 public class LineChart<X,Y> extends XYChart<X,Y> {
  80 
  81     // -------------- PRIVATE FIELDS ------------------------------------------
  82 
  83     /** A multiplier for the Y values that we store for each series, it is used to animate in a new series */
  84     private Map<Series<X,Y>, DoubleProperty> seriesYMultiplierMap = new HashMap<>();
  85     private Legend legend = new Legend();
  86     private Timeline dataRemoveTimeline;
  87     private Series<X,Y> seriesOfDataRemoved = null;
  88     private Data<X,Y> dataItemBeingRemoved = null;
  89     private FadeTransition fadeSymbolTransition = null;
  90     private Map<Data<X,Y>, Double> XYValueMap = 
  91                                 new HashMap<Data<X,Y>, Double>();
  92     private Timeline seriesRemoveTimeline = null;
  93     // -------------- PUBLIC PROPERTIES ----------------------------------------
  94 
  95     /** When true, CSS styleable symbols are created for any data items that don't have a symbol node specified. */
  96     private BooleanProperty createSymbols = new StyleableBooleanProperty(true) {
  97         @Override protected void invalidated() {
  98             for (int seriesIndex=0; seriesIndex < getData().size(); seriesIndex ++) {
  99                 Series<X,Y> series = getData().get(seriesIndex);
 100                 for (int itemIndex=0; itemIndex < series.getData().size(); itemIndex ++) {
 101                     Data<X,Y> item = series.getData().get(itemIndex);
 102                     Node symbol = item.getNode();
 103                     if(get() && symbol == null) { // create any symbols
 104                         symbol = createSymbol(series, getData().indexOf(series), item, itemIndex);
 105                         getPlotChildren().add(symbol);
 106                     } else if (!get() && symbol != null) { // remove symbols
 107                         getPlotChildren().remove(symbol);
 108                         symbol = null;
 109                         item.setNode(null);
 110                     }
 111                 }
 112             }
 113             requestChartLayout();
 114         }
 115 
 116         public Object getBean() {
 117             return LineChart.this;
 118         }
 119 
 120         public String getName() {
 121             return "createSymbols";
 122         }
 123 
 124         public CssMetaData<LineChart<?,?>,Boolean> getCssMetaData() {
 125             return StyleableProperties.CREATE_SYMBOLS;
 126         }
 127     };
 128 
 129     /**
 130      * Indicates whether symbols for data points will be created or not.
 131      *
 132      * @return true if symbols for data points will be created and false otherwise.
 133      */
 134     public final boolean getCreateSymbols() { return createSymbols.getValue(); }
 135     public final void setCreateSymbols(boolean value) { createSymbols.setValue(value); }
 136     public final BooleanProperty createSymbolsProperty() { return createSymbols; }
 137 
 138 
 139     /**
 140      * Indicates whether the data passed to LineChart should be sorted by natural order of one of the axes.
 141      * If this is set to {@link SortingPolicy#NONE}, the order in {@link #dataProperty()} will be used.
 142      *
 143      * @since JavaFX 8u40
 144      * @see SortingPolicy
 145      * @defaultValue SortingPolicy#X_AXIS
 146      */
 147     private ObjectProperty<SortingPolicy> axisSortingPolicy = new ObjectPropertyBase<SortingPolicy>(SortingPolicy.X_AXIS) {
 148         @Override protected void invalidated() {
 149             requestChartLayout();
 150         }
 151 
 152         public Object getBean() {
 153             return LineChart.this;
 154         }
 155 
 156         public String getName() {
 157             return "axisSortingPolicy";
 158         }
 159 
 160     };
 161 
 162     public final SortingPolicy getAxisSortingPolicy() { return axisSortingPolicy.getValue(); }
 163     public final void setAxisSortingPolicy(SortingPolicy value) { axisSortingPolicy.setValue(value); }
 164     public final ObjectProperty<SortingPolicy> axisSortingPolicyProperty() { return axisSortingPolicy; }
 165 
 166     // -------------- CONSTRUCTORS ----------------------------------------------
 167 
 168     /**
 169      * Construct a new LineChart with the given axis.
 170      *
 171      * @param xAxis The x axis to use
 172      * @param yAxis The y axis to use
 173      */
 174     public LineChart(@NamedArg("xAxis") Axis<X> xAxis, @NamedArg("yAxis") Axis<Y> yAxis) {
 175         this(xAxis, yAxis, FXCollections.<Series<X, Y>>observableArrayList());
 176     }
 177 
 178     /**
 179      * Construct a new LineChart with the given axis and data.
 180      *
 181      * @param xAxis The x axis to use
 182      * @param yAxis The y axis to use
 183      * @param data The data to use, this is the actual list used so any changes to it will be reflected in the chart
 184      */
 185     public LineChart(@NamedArg("xAxis") Axis<X> xAxis, @NamedArg("yAxis") Axis<Y> yAxis, @NamedArg("data") ObservableList<Series<X,Y>> data) {
 186         super(xAxis,yAxis);
 187         setLegend(legend);
 188         setData(data);
 189     }
 190 
 191     // -------------- METHODS ------------------------------------------------------------------------------------------
 192 
 193     /** @inheritDoc */
 194     @Override protected void updateAxisRange() {
 195         final Axis<X> xa = getXAxis();
 196         final Axis<Y> ya = getYAxis();
 197         List<X> xData = null;
 198         List<Y> yData = null;
 199         if(xa.isAutoRanging()) xData = new ArrayList<X>();
 200         if(ya.isAutoRanging()) yData = new ArrayList<Y>();
 201         if(xData != null || yData != null) {
 202             for(Series<X,Y> series : getData()) {
 203                 for(Data<X,Y> data: series.getData()) {
 204                     if(xData != null) xData.add(data.getXValue());
 205                     if(yData != null) yData.add(data.getYValue());
 206                 }
 207             }
 208             // RT-32838 No need to invalidate range if there is one data item - whose value is zero. 
 209             if(xData != null && !(xData.size() == 1 && getXAxis().toNumericValue(xData.get(0)) == 0)) {
 210                 xa.invalidateRange(xData);
 211             }
 212             if(yData != null && !(yData.size() == 1 && getYAxis().toNumericValue(yData.get(0)) == 0)) {
 213                 ya.invalidateRange(yData);
 214             }
 215             
 216         }
 217     }
 218     
 219     @Override protected void dataItemAdded(final Series<X,Y> series, int itemIndex, final Data<X,Y> item) {
 220         final Node symbol = createSymbol(series, getData().indexOf(series), item, itemIndex);
 221         if (shouldAnimate()) {
 222             if (dataRemoveTimeline != null && dataRemoveTimeline.getStatus().equals(Animation.Status.RUNNING)) {
 223                 if (seriesOfDataRemoved == series) {
 224                     dataRemoveTimeline.stop();
 225                     dataRemoveTimeline = null;
 226                     getPlotChildren().remove(dataItemBeingRemoved.getNode());
 227                     removeDataItemFromDisplay(seriesOfDataRemoved, dataItemBeingRemoved);
 228                     seriesOfDataRemoved = null;
 229                     dataItemBeingRemoved = null;
 230                 }
 231             }
 232             boolean animate = false;
 233             if (itemIndex > 0 && itemIndex < (series.getData().size()-1)) {
 234                 animate = true;
 235                 Data<X,Y> p1 = series.getData().get(itemIndex - 1);
 236                 Data<X,Y> p2 = series.getData().get(itemIndex + 1);
 237                 if (p1 != null && p2 != null) {
 238                     double x1 = getXAxis().toNumericValue(p1.getXValue());
 239                     double y1 = getYAxis().toNumericValue(p1.getYValue());
 240                     double x3 = getXAxis().toNumericValue(p2.getXValue());
 241                     double y3 = getYAxis().toNumericValue(p2.getYValue());
 242 
 243                     double x2 = getXAxis().toNumericValue(item.getXValue());
 244                     //double y2 = getYAxis().toNumericValue(item.getYValue());
 245                     if (x2 > x1 && x2 < x3) {
 246                          //1. y intercept of the line : y = ((y3-y1)/(x3-x1)) * x2 + (x3y1 - y3x1)/(x3 -x1)
 247                         double y = ((y3-y1)/(x3-x1)) * x2 + (x3*y1 - y3*x1)/(x3-x1);
 248                         item.setCurrentY(getYAxis().toRealValue(y));
 249                         item.setCurrentX(getXAxis().toRealValue(x2));
 250                     } else {
 251                         //2. we can simply use the midpoint on the line as well..
 252                         double x = (x3 + x1)/2;
 253                         double y = (y3 + y1)/2;
 254                         item.setCurrentX(getXAxis().toRealValue(x));
 255                         item.setCurrentY(getYAxis().toRealValue(y));
 256                     }
 257                 }
 258             } else if (itemIndex == 0 && series.getData().size() > 1) {
 259                 animate = true;
 260                 item.setCurrentX(series.getData().get(1).getXValue());
 261                 item.setCurrentY(series.getData().get(1).getYValue());
 262             } else if (itemIndex == (series.getData().size() - 1) && series.getData().size() > 1) {
 263                 animate = true;
 264                 int last = series.getData().size() - 2;
 265                 item.setCurrentX(series.getData().get(last).getXValue());
 266                 item.setCurrentY(series.getData().get(last).getYValue());
 267             } else if(symbol != null) {
 268                 // fade in new symbol
 269                 symbol.setOpacity(0);
 270                 getPlotChildren().add(symbol);
 271                 FadeTransition ft = new FadeTransition(Duration.millis(500),symbol);
 272                 ft.setToValue(1);
 273                 ft.play();
 274             }
 275             if (animate) {
 276                 animate(
 277                     new KeyFrame(Duration.ZERO,
 278                             (e) -> { if (symbol != null && !getPlotChildren().contains(symbol)) getPlotChildren().add(symbol); },
 279                                    new KeyValue(item.currentYProperty(),
 280                                         item.getCurrentY()),
 281                                         new KeyValue(item.currentXProperty(),
 282                                         item.getCurrentX())),
 283                     new KeyFrame(Duration.millis(700), new KeyValue(item.currentYProperty(),
 284                                         item.getYValue(), Interpolator.EASE_BOTH),
 285                                         new KeyValue(item.currentXProperty(),
 286                                         item.getXValue(), Interpolator.EASE_BOTH))
 287                 );
 288             }
 289             
 290         } else {
 291             if (symbol != null) getPlotChildren().add(symbol);
 292         }
 293     }
 294 
 295     @Override protected  void dataItemRemoved(final Data<X,Y> item, final Series<X,Y> series) {
 296         final Node symbol = item.getNode();
 297 
 298         if (symbol != null) {
 299             symbol.focusTraversableProperty().unbind();
 300         }
 301 
 302         // remove item from sorted list
 303         int itemIndex = series.getItemIndex(item);
 304         if (shouldAnimate()) {
 305             XYValueMap.clear();
 306             boolean animate = false;
 307             if (itemIndex > 0 && itemIndex < series.getDataSize()) {
 308                 animate = true;
 309                 Data<X,Y> p1 = series.getItem(itemIndex - 1);
 310                 Data<X,Y> p2 = series.getItem(itemIndex + 1);
 311                 if (p1 != null && p2 != null) {
 312                     double x1 = getXAxis().toNumericValue(p1.getXValue());
 313                     double y1 = getYAxis().toNumericValue(p1.getYValue());
 314                     double x3 = getXAxis().toNumericValue(p2.getXValue());
 315                     double y3 = getYAxis().toNumericValue(p2.getYValue());
 316 
 317                     double x2 = getXAxis().toNumericValue(item.getXValue());
 318                     double y2 = getYAxis().toNumericValue(item.getYValue());
 319                     if (x2 > x1 && x2 < x3) {
 320     //                //1.  y intercept of the line : y = ((y3-y1)/(x3-x1)) * x2 + (x3y1 - y3x1)/(x3 -x1)
 321                         double y = ((y3-y1)/(x3-x1)) * x2 + (x3*y1 - y3*x1)/(x3-x1);
 322                         item.setCurrentX(getXAxis().toRealValue(x2));
 323                         item.setCurrentY(getYAxis().toRealValue(y2));
 324                         item.setXValue(getXAxis().toRealValue(x2));
 325                         item.setYValue(getYAxis().toRealValue(y));
 326                     } else {
 327                     //2.  we can simply use the midpoint on the line as well..
 328                         double x = (x3 + x1)/2;
 329                         double y = (y3 + y1)/2;
 330                         item.setCurrentX(getXAxis().toRealValue(x));
 331                         item.setCurrentY(getYAxis().toRealValue(y));
 332                     }
 333                 }
 334             } else if (itemIndex == 0 && series.getDataSize() > 1) {
 335                 animate = true;
 336                 Iterator<Data<X,Y>> iter = getDisplayedDataIterator(series);
 337                 if (iter.hasNext()) { // get first data value
 338                     Data<X,Y> d = iter.next();
 339                     item.setXValue(d.getXValue());
 340                     item.setYValue(d.getYValue());
 341                 }
 342             } else if (itemIndex == (series.getDataSize() - 1) && series.getDataSize() > 1) {
 343                 animate = true;
 344                 int last = series.getData().size() - 1;
 345                 item.setXValue(series.getData().get(last).getXValue());
 346                 item.setYValue(series.getData().get(last).getYValue());
 347             } else {
 348                 // fade out symbol
 349                 if (symbol != null) {
 350                     fadeSymbolTransition = new FadeTransition(Duration.millis(500),symbol);
 351                     fadeSymbolTransition.setToValue(0);
 352                     fadeSymbolTransition.setOnFinished(actionEvent -> {
 353                         item.setSeries(null);
 354                         getPlotChildren().remove(symbol);
 355                         removeDataItemFromDisplay(series, item);
 356                         symbol.setOpacity(1.0);
 357                     });
 358                     fadeSymbolTransition.play();
 359                 }
 360             }
 361             if (animate) {
 362                 dataRemoveTimeline = createDataRemoveTimeline(item, symbol, series);
 363                 seriesOfDataRemoved = series;
 364                 dataItemBeingRemoved = item;
 365                 dataRemoveTimeline.play();
 366             }
 367         } else {
 368             item.setSeries(null);
 369             if (symbol != null) getPlotChildren().remove(symbol);
 370             removeDataItemFromDisplay(series, item);
 371         }
 372         //Note: better animation here, point should move from old position to new position at center point between prev and next symbols
 373     }
 374 
 375     /** @inheritDoc */
 376     @Override protected void dataItemChanged(Data<X, Y> item) {
 377     }
 378     
 379     @Override protected void seriesChanged(ListChangeListener.Change<? extends Series> c) {
 380         // Update style classes for all series lines and symbols
 381         // Note: is there a more efficient way of doing this?
 382         for (int i = 0; i < getDataSize(); i++) {
 383             final Series<X,Y> s = getData().get(i);
 384             Node seriesNode = s.getNode();
 385             if(seriesNode != null) seriesNode.getStyleClass().setAll("chart-series-line", "series" + i, s.defaultColorStyleClass);
 386         }
 387     }
 388 
 389     @Override protected  void seriesAdded(Series<X,Y> series, int seriesIndex) {
 390         // create new path for series
 391         Path seriesLine = new Path();
 392         seriesLine.setStrokeLineJoin(StrokeLineJoin.BEVEL);
 393         series.setNode(seriesLine);
 394         // create series Y multiplier
 395         DoubleProperty seriesYAnimMultiplier = new SimpleDoubleProperty(this, "seriesYMultiplier");
 396         seriesYMultiplierMap.put(series, seriesYAnimMultiplier);
 397         // handle any data already in series
 398         if (shouldAnimate()) {
 399             seriesLine.setOpacity(0);
 400             seriesYAnimMultiplier.setValue(0d);
 401         } else {
 402             seriesYAnimMultiplier.setValue(1d);
 403         }
 404         getPlotChildren().add(seriesLine);
 405 
 406         List<KeyFrame> keyFrames = new ArrayList<KeyFrame>();
 407         if (shouldAnimate()) {
 408             // animate in new series
 409             keyFrames.add(new KeyFrame(Duration.ZERO,
 410                 new KeyValue(seriesLine.opacityProperty(), 0),
 411                 new KeyValue(seriesYAnimMultiplier, 0)
 412             ));
 413             keyFrames.add(new KeyFrame(Duration.millis(200),
 414                 new KeyValue(seriesLine.opacityProperty(), 1)
 415             ));
 416             keyFrames.add(new KeyFrame(Duration.millis(500),
 417                 new KeyValue(seriesYAnimMultiplier, 1)
 418             ));
 419         }
 420         for (int j=0; j<series.getData().size(); j++) {
 421             Data<X,Y> item = series.getData().get(j);
 422             final Node symbol = createSymbol(series, seriesIndex, item, j);
 423             if(symbol != null) {
 424                 if (shouldAnimate()) symbol.setOpacity(0);
 425                 getPlotChildren().add(symbol);
 426                 if (shouldAnimate()) {
 427                     // fade in new symbol
 428                     keyFrames.add(new KeyFrame(Duration.ZERO, new KeyValue(symbol.opacityProperty(), 0)));
 429                     keyFrames.add(new KeyFrame(Duration.millis(200), new KeyValue(symbol.opacityProperty(), 1)));
 430                 }
 431             }
 432         }
 433         if (shouldAnimate()) animate(keyFrames.toArray(new KeyFrame[keyFrames.size()]));
 434     }
 435     private void updateDefaultColorIndex(final Series<X,Y> series) {
 436         int clearIndex = seriesColorMap.get(series);
 437         series.getNode().getStyleClass().remove(DEFAULT_COLOR+clearIndex);
 438         for (int j=0; j < series.getData().size(); j++) {
 439             final Node node = series.getData().get(j).getNode();
 440             if(node!=null) {
 441                 node.getStyleClass().remove(DEFAULT_COLOR+clearIndex);
 442             }
 443         }
 444     }
 445 
 446     @Override protected  void seriesRemoved(final Series<X,Y> series) {
 447         updateDefaultColorIndex(series);
 448         // remove all symbol nodes
 449         seriesYMultiplierMap.remove(series);
 450         if (shouldAnimate()) {
 451             seriesRemoveTimeline = new Timeline(createSeriesRemoveTimeLine(series, 900));
 452             seriesRemoveTimeline.play();
 453         } else {
 454             getPlotChildren().remove(series.getNode());
 455             for (Data<X,Y> d:series.getData()) getPlotChildren().remove(d.getNode());
 456             removeSeriesFromDisplay(series);
 457         }
 458     }
 459 
 460     /** @inheritDoc */
 461     @Override protected void layoutPlotChildren() {
 462         List<LineTo> constructedPath = new ArrayList<>(getDataSize());
 463         for (int seriesIndex=0; seriesIndex < getDataSize(); seriesIndex++) {
 464             Series<X,Y> series = getData().get(seriesIndex);
 465             final DoubleProperty seriesYAnimMultiplier = seriesYMultiplierMap.get(series);
 466             if(series.getNode() instanceof  Path) {
 467                 final ObservableList<PathElement> seriesLine = ((Path)series.getNode()).getElements();
 468                 seriesLine.clear();
 469                 constructedPath.clear();
 470                 for (Iterator<Data<X, Y>> it = getDisplayedDataIterator(series); it.hasNext(); ) {
 471                     Data<X, Y> item = it.next();
 472                     double x = getXAxis().getDisplayPosition(item.getCurrentX());
 473                     double y = getYAxis().getDisplayPosition(
 474                             getYAxis().toRealValue(getYAxis().toNumericValue(item.getCurrentY()) * seriesYAnimMultiplier.getValue()));
 475                     if (Double.isNaN(x) || Double.isNaN(y)) {
 476                         continue;
 477                     }
 478                     constructedPath.add(new LineTo(x, y));
 479 
 480                     Node symbol = item.getNode();
 481                     if (symbol != null) {
 482                         final double w = symbol.prefWidth(-1);
 483                         final double h = symbol.prefHeight(-1);
 484                         symbol.resizeRelocate(x-(w/2), y-(h/2),w,h);
 485                     }
 486                 }
 487                 switch (getAxisSortingPolicy()) {
 488                     case X_AXIS:
 489                         Collections.sort(constructedPath, (e1, e2) -> Double.compare(e1.getX(), e2.getX()));
 490                         break;
 491                     case Y_AXIS:
 492                         Collections.sort(constructedPath, (e1, e2) -> Double.compare(e1.getY(), e2.getY()));
 493                         break;
 494                 }
 495 
 496                 if (!constructedPath.isEmpty()) {
 497                     LineTo first = constructedPath.get(0);
 498                     seriesLine.add(new MoveTo(first.getX(), first.getY()));
 499                     seriesLine.addAll(constructedPath);
 500                 }
 501             }
 502         }
 503     }
 504     /** @inheritDoc */
 505     @Override void dataBeingRemovedIsAdded(Data item, Series series) {
 506         if (fadeSymbolTransition != null) {
 507             fadeSymbolTransition.setOnFinished(null);
 508             fadeSymbolTransition.stop();
 509         }
 510         if (dataRemoveTimeline != null) {
 511             dataRemoveTimeline.setOnFinished(null);
 512             dataRemoveTimeline.stop();
 513         }
 514         final Node symbol = item.getNode();
 515         if (symbol != null) getPlotChildren().remove(symbol);
 516         
 517         item.setSeries(null);
 518         removeDataItemFromDisplay(series, item);
 519         
 520         // restore values to item
 521         Double value = XYValueMap.get(item);
 522         if (value != null) {
 523             item.setYValue(value);
 524             item.setCurrentY(value);
 525         }
 526         XYValueMap.clear();
 527     }
 528     /** @inheritDoc */
 529     @Override void seriesBeingRemovedIsAdded(Series<X,Y> series) {
 530         if (seriesRemoveTimeline != null) {
 531             seriesRemoveTimeline.setOnFinished(null);
 532             seriesRemoveTimeline.stop();
 533             getPlotChildren().remove(series.getNode());
 534             for (Data<X,Y> d:series.getData()) getPlotChildren().remove(d.getNode());
 535             removeSeriesFromDisplay(series);
 536         }
 537     }
 538 
 539     private Timeline createDataRemoveTimeline(final Data<X,Y> item, final Node symbol, final Series<X,Y> series) {
 540         Timeline t = new Timeline();
 541         // save data values in case the same data item gets added immediately.
 542         XYValueMap.put(item, ((Number)item.getYValue()).doubleValue());
 543             
 544         t.getKeyFrames().addAll(new KeyFrame(Duration.ZERO, new KeyValue(item.currentYProperty(),
 545                 item.getCurrentY()), new KeyValue(item.currentXProperty(),
 546                 item.getCurrentX())),
 547                 new KeyFrame(Duration.millis(500), actionEvent -> {
 548                     if (symbol != null) getPlotChildren().remove(symbol);
 549                     removeDataItemFromDisplay(series, item);
 550                     XYValueMap.clear();
 551                 },
 552                 new KeyValue(item.currentYProperty(),
 553                 item.getYValue(), Interpolator.EASE_BOTH),
 554                 new KeyValue(item.currentXProperty(),
 555                 item.getXValue(), Interpolator.EASE_BOTH))
 556         );
 557         return t;
 558     }
 559 
 560     private Node createSymbol(Series<X, Y> series, int seriesIndex, final Data<X,Y> item, int itemIndex) {
 561         Node symbol = item.getNode();
 562         // check if symbol has already been created
 563         if (symbol == null && getCreateSymbols()) {
 564             symbol = new StackPane();
 565             symbol.setAccessibleRole(AccessibleRole.TEXT);
 566             symbol.setAccessibleRoleDescription("Point");
 567             symbol.focusTraversableProperty().bind(Platform.accessibilityActiveProperty());
 568             item.setNode(symbol);
 569         }
 570         // set symbol styles
 571         if (symbol != null) symbol.getStyleClass().addAll("chart-line-symbol", "series" + seriesIndex,
 572                 "data" + itemIndex, series.defaultColorStyleClass);
 573         return symbol;
 574     }
 575 
 576     /**
 577      * This is called whenever a series is added or removed and the legend needs to be updated
 578      */
 579      @Override protected void updateLegend() {
 580         legend.getItems().clear();
 581         if (getData() != null) {
 582             for (int seriesIndex=0; seriesIndex < getData().size(); seriesIndex++) {
 583                 Series<X,Y> series = getData().get(seriesIndex);
 584                 LegendItem legenditem = new LegendItem(series.getName());
 585                 legenditem.getSymbol().getStyleClass().addAll("chart-line-symbol", "series"+seriesIndex, series.defaultColorStyleClass);
 586                 legend.getItems().add(legenditem);
 587             }
 588         }
 589         if (legend.getItems().size() > 0) {
 590             if (getLegend() == null) {
 591                 setLegend(legend);
 592             }
 593         } else {
 594             setLegend(null);
 595         }
 596     }
 597 
 598     // -------------- STYLESHEET HANDLING --------------------------------------
 599 
 600     private static class StyleableProperties {
 601         private static final CssMetaData<LineChart<?,?>,Boolean> CREATE_SYMBOLS = 
 602             new CssMetaData<LineChart<?,?>,Boolean>("-fx-create-symbols",
 603                 BooleanConverter.getInstance(), Boolean.TRUE) {
 604 
 605             @Override
 606             public boolean isSettable(LineChart<?,?> node) {
 607                 return node.createSymbols == null || !node.createSymbols.isBound();
 608             }
 609 
 610             @Override
 611             public StyleableProperty<Boolean> getStyleableProperty(LineChart<?,?> node) {
 612                 return (StyleableProperty<Boolean>)(WritableValue<Boolean>)node.createSymbolsProperty();
 613             }
 614         };
 615 
 616         private static final List<CssMetaData<? extends Styleable, ?>> STYLEABLES;
 617         static {
 618             final List<CssMetaData<? extends Styleable, ?>> styleables =
 619                 new ArrayList<CssMetaData<? extends Styleable, ?>>(XYChart.getClassCssMetaData());
 620             styleables.add(CREATE_SYMBOLS);
 621             STYLEABLES = Collections.unmodifiableList(styleables);
 622         }
 623     }
 624 
 625     /**
 626      * @return The CssMetaData associated with this class, which may include the
 627      * CssMetaData of its super classes.
 628      * @since JavaFX 8.0
 629      */
 630     public static List<CssMetaData<? extends Styleable, ?>> getClassCssMetaData() {
 631         return StyleableProperties.STYLEABLES;
 632     }
 633 
 634     /**
 635      * {@inheritDoc}
 636      * @since JavaFX 8.0
 637      */
 638     @Override
 639     public List<CssMetaData<? extends Styleable, ?>> getCssMetaData() {
 640         return getClassCssMetaData();
 641     }
 642 
 643     /**
 644      * This enum defines a policy for {@link LineChart#axisSortingPolicyProperty()}.
 645      * @since JavaFX 8u40
 646      */
 647     public static enum SortingPolicy {
 648         /**
 649          * The data should be left in the order defined by the list in {@link javafx.scene.chart.LineChart#dataProperty()}.
 650          */
 651         NONE,
 652         /**
 653          * The data is ordered by x axis.
 654          */
 655         X_AXIS,
 656         /**
 657          * The data is ordered by y axis.
 658          */
 659         Y_AXIS
 660     }
 661 }