001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.gui.mappaint;
003
004import java.awt.Color;
005import java.util.ArrayList;
006import java.util.Collection;
007import java.util.Collections;
008import java.util.HashMap;
009import java.util.List;
010import java.util.Map;
011import java.util.Map.Entry;
012import java.util.Objects;
013import java.util.Optional;
014
015import org.openstreetmap.josm.data.osm.INode;
016import org.openstreetmap.josm.data.osm.IPrimitive;
017import org.openstreetmap.josm.data.osm.IRelation;
018import org.openstreetmap.josm.data.osm.IWay;
019import org.openstreetmap.josm.data.osm.Relation;
020import org.openstreetmap.josm.data.osm.visitor.paint.PaintColors;
021import org.openstreetmap.josm.data.osm.visitor.paint.relations.Multipolygon;
022import org.openstreetmap.josm.data.osm.visitor.paint.relations.MultipolygonCache;
023import org.openstreetmap.josm.data.preferences.NamedColorProperty;
024import org.openstreetmap.josm.gui.MainApplication;
025import org.openstreetmap.josm.gui.NavigatableComponent;
026import org.openstreetmap.josm.gui.layer.OsmDataLayer;
027import org.openstreetmap.josm.gui.mappaint.DividedScale.RangeViolatedError;
028import org.openstreetmap.josm.gui.mappaint.mapcss.MapCSSStyleSource;
029import org.openstreetmap.josm.gui.mappaint.styleelement.AreaElement;
030import org.openstreetmap.josm.gui.mappaint.styleelement.AreaIconElement;
031import org.openstreetmap.josm.gui.mappaint.styleelement.BoxTextElement;
032import org.openstreetmap.josm.gui.mappaint.styleelement.DefaultStyles;
033import org.openstreetmap.josm.gui.mappaint.styleelement.LineElement;
034import org.openstreetmap.josm.gui.mappaint.styleelement.NodeElement;
035import org.openstreetmap.josm.gui.mappaint.styleelement.RepeatImageElement;
036import org.openstreetmap.josm.gui.mappaint.styleelement.StyleElement;
037import org.openstreetmap.josm.gui.mappaint.styleelement.TextElement;
038import org.openstreetmap.josm.gui.mappaint.styleelement.TextLabel;
039import org.openstreetmap.josm.gui.util.GuiHelper;
040import org.openstreetmap.josm.spi.preferences.Config;
041import org.openstreetmap.josm.spi.preferences.PreferenceChangeEvent;
042import org.openstreetmap.josm.spi.preferences.PreferenceChangedListener;
043import org.openstreetmap.josm.tools.ColorHelper;
044import org.openstreetmap.josm.tools.Pair;
045
046/**
047 * Generates a list of {@link StyleElement}s for a primitive, to
048 * be drawn on the map.
049 * There are several steps to derive the list of elements for display:
050 * <ol>
051 * <li>{@link #generateStyles(IPrimitive, double, boolean)} applies the
052 * {@link StyleSource}s one after another to get a key-value map of MapCSS
053 * properties. Then a preliminary set of StyleElements is derived from the
054 * properties map.</li>
055 * <li>{@link #getImpl(IPrimitive, double, NavigatableComponent)} handles the
056 * different forms of multipolygon tagging.</li>
057 * <li>{@link #getStyleCacheWithRange(IPrimitive, double, NavigatableComponent)}
058 * adds a default StyleElement for primitives that would be invisible otherwise.
059 * (For example untagged nodes and ways.)</li>
060 * </ol>
061 * The results are cached with respect to the current scale.
062 *
063 * Use {@link #setStyleSources(Collection)} to select the StyleSources that are applied.
064 */
065public class ElemStyles implements PreferenceChangedListener {
066    private final List<StyleSource> styleSources = Collections.synchronizedList(new ArrayList<>());
067    private boolean drawMultipolygon;
068
069    private short cacheIdx = 1;
070
071    private boolean defaultNodes;
072    private boolean defaultLines;
073
074    private short defaultNodesIdx;
075    private short defaultLinesIdx;
076
077    private final Map<String, String> preferenceCache = Collections.synchronizedMap(new HashMap<>());
078
079    private volatile Color backgroundColorCache;
080
081    /**
082     * Constructs a new {@code ElemStyles}.
083     */
084    public ElemStyles() {
085        Config.getPref().addPreferenceChangeListener(this);
086    }
087
088    /**
089     * Constructs a new {@code ElemStyles} with specific style sources. This does not listen to preference changes,
090     * and therefore should only be used with layers that have specific drawing requirements.
091     *
092     * @param sources The style sources (these cannot be added to, or removed from)
093     * @since 17862
094     */
095    public ElemStyles(Collection<StyleSource> sources) {
096        this.styleSources.addAll(sources);
097    }
098
099    /**
100     * Clear the style cache for all primitives of all DataSets.
101     */
102    public void clearCached() {
103        // run in EDT to make sure this isn't called during rendering run
104        GuiHelper.runInEDT(() -> {
105            cacheIdx++;
106            preferenceCache.clear();
107            backgroundColorCache = null;
108            MainApplication.getLayerManager().getLayersOfType(OsmDataLayer.class).forEach(
109                    dl -> dl.data.clearMappaintCache());
110        });
111    }
112
113    /**
114     * Returns the list of style sources.
115     * @return the list of style sources
116     */
117    public List<StyleSource> getStyleSources() {
118        return Collections.<StyleSource>unmodifiableList(styleSources);
119    }
120
121    /**
122     * Returns the background color.
123     * @return the background color
124     */
125    public Color getBackgroundColor() {
126        if (backgroundColorCache != null)
127            return backgroundColorCache;
128        for (StyleSource s : styleSources) {
129            if (!s.active) {
130                continue;
131            }
132            Color backgroundColorOverride = s.getBackgroundColorOverride();
133            if (backgroundColorOverride != null) {
134                backgroundColorCache = backgroundColorOverride;
135            }
136        }
137        return Optional.ofNullable(backgroundColorCache).orElseGet(PaintColors.BACKGROUND::get);
138    }
139
140    /**
141     * Create the list of styles for one primitive.
142     *
143     * @param osm the primitive
144     * @param scale the scale (in meters per 100 pixel)
145     * @param nc display component
146     * @return list of styles
147     * @since 13810 (signature)
148     */
149    public StyleElementList get(IPrimitive osm, double scale, NavigatableComponent nc) {
150        return getStyleCacheWithRange(osm, scale, nc).a;
151    }
152
153    /**
154     * Create the list of styles and its valid scale range for one primitive.
155     *
156     * Automatically adds default styles in case no proper style was found.
157     * Uses the cache, if possible, and saves the results to the cache.
158     * @param osm OSM primitive
159     * @param scale scale
160     * @param nc navigable component
161     * @return pair containing style list and range
162     * @since 13810 (signature)
163     */
164    public Pair<StyleElementList, Range> getStyleCacheWithRange(IPrimitive osm, double scale, NavigatableComponent nc) {
165        synchronized (osm.getStyleCacheSyncObject()) {
166            if (!osm.isCachedStyleUpToDate() || scale <= 0) {
167                osm.setCachedStyle(StyleCache.EMPTY_STYLECACHE);
168            } else {
169                Pair<StyleElementList, Range> lst = osm.getCachedStyle().getWithRange(scale, osm.isSelected());
170                if (lst.a != null)
171                    return lst;
172            }
173            Pair<StyleElementList, Range> p = getImpl(osm, scale, nc);
174            if (osm instanceof INode && isDefaultNodes()) {
175                if (p.a.isEmpty()) {
176                    if (TextLabel.AUTO_LABEL_COMPOSITION_STRATEGY.compose(osm) != null) {
177                        p.a = DefaultStyles.DEFAULT_NODE_STYLELIST_TEXT;
178                    } else {
179                        p.a = DefaultStyles.DEFAULT_NODE_STYLELIST;
180                    }
181                } else {
182                    boolean hasNonModifier = false;
183                    boolean hasText = false;
184                    for (StyleElement s : p.a) {
185                        if (s instanceof BoxTextElement) {
186                            hasText = true;
187                        } else {
188                            if (!s.isModifier) {
189                                hasNonModifier = true;
190                            }
191                        }
192                    }
193                    if (!hasNonModifier) {
194                        p.a = new StyleElementList(p.a, DefaultStyles.SIMPLE_NODE_ELEMSTYLE);
195                        if (!hasText && TextLabel.AUTO_LABEL_COMPOSITION_STRATEGY.compose(osm) != null) {
196                            p.a = new StyleElementList(p.a, DefaultStyles.SIMPLE_NODE_TEXT_ELEMSTYLE);
197                        }
198                    }
199                }
200            } else if (osm instanceof IWay && isDefaultLines()) {
201                boolean hasProperLineStyle = false;
202                for (StyleElement s : p.a) {
203                    if (s.isProperLineStyle()) {
204                        hasProperLineStyle = true;
205                        break;
206                    }
207                }
208                if (!hasProperLineStyle) {
209                    LineElement line = LineElement.UNTAGGED_WAY;
210                    for (StyleElement element : p.a) {
211                        if (element instanceof AreaElement) {
212                            line = LineElement.createSimpleLineStyle(((AreaElement) element).color, true);
213                            break;
214                        }
215                    }
216                    p.a = new StyleElementList(p.a, line);
217                }
218            }
219            StyleCache style = osm.getCachedStyle() != null ? osm.getCachedStyle() : StyleCache.EMPTY_STYLECACHE;
220            try {
221                osm.setCachedStyle(style.put(p.a, p.b, osm.isSelected()));
222            } catch (RangeViolatedError e) {
223                throw new AssertionError("Range violated: " + e.getMessage()
224                  + " (object: " + osm.getPrimitiveId() + ", current style: " + osm.getCachedStyle()
225                  + ", scale: " + scale + ", new stylelist: " + p.a + ", new range: " + p.b + ')', e);
226            }
227            osm.declareCachedStyleUpToDate();
228            return p;
229        }
230    }
231
232    /**
233     * Create the list of styles and its valid scale range for one primitive.
234     *
235     * This method does multipolygon handling.
236     *
237     * If the primitive is a way, look for multipolygon parents. In case it
238     * is indeed member of some multipolygon as role "outer", all area styles
239     * are removed. (They apply to the multipolygon area.)
240     * Outer ways can have their own independent line styles, e.g. a road as
241     * boundary of a forest. Otherwise, in case, the way does not have an
242     * independent line style, take a line style from the multipolygon.
243     * If the multipolygon does not have a line style either, at least create a
244     * default line style from the color of the area.
245     *
246     * Now consider the case that the way is not an outer way of any multipolygon,
247     * but is member of a multipolygon as "inner".
248     * First, the style list is regenerated, considering only tags of this way.
249     * Then check, if the way describes something in its own right. (linear feature
250     * or area) If not, add a default line style from the area color of the multipolygon.
251     *
252     * @param osm OSM primitive
253     * @param scale scale
254     * @param nc navigable component
255     * @return pair containing style list and range
256     */
257    private Pair<StyleElementList, Range> getImpl(IPrimitive osm, double scale, NavigatableComponent nc) {
258        if (osm instanceof INode)
259            return generateStyles(osm, scale, false);
260        else if (osm instanceof IWay) {
261            Pair<StyleElementList, Range> p = generateStyles(osm, scale, false);
262
263            boolean isOuterWayOfSomeMP = false;
264            Color wayColor = null;
265
266            // FIXME: Maybe in the future outer way styles apply to outers ignoring the multipolygon?
267            for (IPrimitive referrer : osm.getReferrers()) {
268                IRelation<?> r = (IRelation<?>) referrer;
269                if (!drawMultipolygon || !r.isMultipolygon() || !r.isUsable() || !(r instanceof Relation)) {
270                    continue;
271                }
272                Multipolygon multipolygon = MultipolygonCache.getInstance().get((Relation) r);
273
274                if (multipolygon.getOuterWays().contains(osm)) {
275                    boolean hasIndependentLineStyle = false;
276                    if (!isOuterWayOfSomeMP) { // do this only one time
277                        List<StyleElement> tmp = new ArrayList<>(p.a.size());
278                        for (StyleElement s : p.a) {
279                            if (s instanceof AreaElement) {
280                                wayColor = ((AreaElement) s).color;
281                            } else {
282                                tmp.add(s);
283                                if (s.isProperLineStyle()) {
284                                    hasIndependentLineStyle = true;
285                                }
286                            }
287                        }
288                        p.a = new StyleElementList(tmp);
289                        isOuterWayOfSomeMP = true;
290                    }
291
292                    if (!hasIndependentLineStyle) {
293                        Pair<StyleElementList, Range> mpElemStyles;
294                        synchronized (r) {
295                            mpElemStyles = getStyleCacheWithRange(r, scale, nc);
296                        }
297                        StyleElement mpLine = null;
298                        for (StyleElement s : mpElemStyles.a) {
299                            if (s.isProperLineStyle()) {
300                                mpLine = s;
301                                break;
302                            }
303                        }
304                        p.b = Range.cut(p.b, mpElemStyles.b);
305                        if (mpLine != null) {
306                            p.a = new StyleElementList(p.a, mpLine);
307                            break;
308                        } else if (wayColor == null && isDefaultLines()) {
309                            for (StyleElement element : mpElemStyles.a) {
310                                if (element instanceof AreaElement) {
311                                    wayColor = ((AreaElement) element).color;
312                                    break;
313                                }
314                            }
315                        }
316                    }
317                }
318            }
319            if (isOuterWayOfSomeMP) {
320                if (isDefaultLines()) {
321                    boolean hasLineStyle = false;
322                    for (StyleElement s : p.a) {
323                        if (s.isProperLineStyle()) {
324                            hasLineStyle = true;
325                            break;
326                        }
327                    }
328                    if (!hasLineStyle) {
329                        p.a = new StyleElementList(p.a, LineElement.createSimpleLineStyle(wayColor, true));
330                    }
331                }
332                return p;
333            }
334
335            if (!isDefaultLines()) return p;
336
337            for (IPrimitive referrer : osm.getReferrers()) {
338                IRelation<?> ref = (IRelation<?>) referrer;
339                if (!drawMultipolygon || !ref.isMultipolygon() || !ref.isUsable() || !(ref instanceof Relation)) {
340                    continue;
341                }
342                final Multipolygon multipolygon = MultipolygonCache.getInstance().get((Relation) ref);
343
344                if (multipolygon.getInnerWays().contains(osm)) {
345                    p = generateStyles(osm, scale, false);
346                    boolean hasIndependentElemStyle = false;
347                    for (StyleElement s : p.a) {
348                        if (s.isProperLineStyle() || s instanceof AreaElement) {
349                            hasIndependentElemStyle = true;
350                            break;
351                        }
352                    }
353                    if (!hasIndependentElemStyle && !multipolygon.getOuterWays().isEmpty()) {
354                        Color mpColor = null;
355                        StyleElementList mpElemStyles;
356                        synchronized (ref) {
357                            mpElemStyles = get(ref, scale, nc);
358                        }
359                        for (StyleElement mpS : mpElemStyles) {
360                            if (mpS instanceof AreaElement) {
361                                mpColor = ((AreaElement) mpS).color;
362                                break;
363                            }
364                        }
365                        p.a = new StyleElementList(p.a, LineElement.createSimpleLineStyle(mpColor, true));
366                    }
367                    return p;
368                }
369            }
370            return p;
371        } else if (osm instanceof IRelation) {
372            return generateStyles(osm, scale, true);
373        }
374        return null;
375    }
376
377    /**
378     * Create the list of styles and its valid scale range for one primitive.
379     *
380     * Loops over the list of style sources, to generate the map of properties.
381     * From these properties, it generates the different types of styles.
382     *
383     * @param osm the primitive to create styles for
384     * @param scale the scale (in meters per 100 px), must be &gt; 0
385     * @param pretendWayIsClosed For styles that require the way to be closed,
386     * we pretend it is. This is useful for generating area styles from the (segmented)
387     * outer ways of a multipolygon.
388     * @return the generated styles and the valid range as a pair
389     * @since 13810 (signature)
390     */
391    public Pair<StyleElementList, Range> generateStyles(IPrimitive osm, double scale, boolean pretendWayIsClosed) {
392        List<StyleElement> sl = new ArrayList<>();
393        MultiCascade mc = new MultiCascade();
394        Environment env = new Environment(osm, mc, null, null);
395
396        for (StyleSource s : styleSources) {
397            if (s.active) {
398                s.apply(mc, osm, scale, pretendWayIsClosed);
399            }
400        }
401
402        for (Entry<String, Cascade> e : mc.getLayers()) {
403            if ("*".equals(e.getKey())) {
404                continue;
405            }
406            env.layer = e.getKey();
407            if (osm instanceof IWay) {
408                AreaElement areaStyle = AreaElement.create(env);
409                addIfNotNull(sl, areaStyle);
410                addIfNotNull(sl, RepeatImageElement.create(env));
411                addIfNotNull(sl, LineElement.createLine(env));
412                addIfNotNull(sl, LineElement.createLeftCasing(env));
413                addIfNotNull(sl, LineElement.createRightCasing(env));
414                addIfNotNull(sl, LineElement.createCasing(env));
415                addIfNotNull(sl, AreaIconElement.create(env));
416                addIfNotNull(sl, TextElement.create(env));
417                if (areaStyle != null) {
418                    //TODO: Warn about this, or even remove it completely
419                    addIfNotNull(sl, TextElement.createForContent(env));
420                }
421            } else if (osm instanceof INode) {
422                NodeElement nodeStyle = NodeElement.create(env);
423                if (nodeStyle != null) {
424                    sl.add(nodeStyle);
425                    addIfNotNull(sl, BoxTextElement.create(env, nodeStyle.getBoxProvider()));
426                } else {
427                    addIfNotNull(sl, BoxTextElement.create(env, DefaultStyles.SIMPLE_NODE_ELEMSTYLE_BOXPROVIDER));
428                }
429            } else if (osm instanceof IRelation) {
430                if (((IRelation<?>) osm).isMultipolygon()) {
431                    AreaElement areaStyle = AreaElement.create(env);
432                    addIfNotNull(sl, areaStyle);
433                    addIfNotNull(sl, RepeatImageElement.create(env));
434                    addIfNotNull(sl, LineElement.createLine(env));
435                    addIfNotNull(sl, LineElement.createCasing(env));
436                    addIfNotNull(sl, AreaIconElement.create(env));
437                    addIfNotNull(sl, TextElement.create(env));
438                    if (areaStyle != null) {
439                        //TODO: Warn about this, or even remove it completely
440                        addIfNotNull(sl, TextElement.createForContent(env));
441                    }
442                } else if (osm.hasTag("type", "restriction")) {
443                    addIfNotNull(sl, NodeElement.create(env));
444                }
445            }
446        }
447        return new Pair<>(new StyleElementList(sl), mc.range);
448    }
449
450    private static <T> void addIfNotNull(List<T> list, T obj) {
451        if (obj != null) {
452            list.add(obj);
453        }
454    }
455
456    /**
457     * Draw a default node symbol for nodes that have no style?
458     * @return {@code true} if default node symbol must be drawn
459     */
460    private boolean isDefaultNodes() {
461        if (defaultNodesIdx == cacheIdx)
462            return defaultNodes;
463        defaultNodes = fromCanvas("default-points", Boolean.TRUE, Boolean.class);
464        defaultNodesIdx = cacheIdx;
465        return defaultNodes;
466    }
467
468    /**
469     * Draw a default line for ways that do not have an own line style?
470     * @return {@code true} if default line must be drawn
471     */
472    private boolean isDefaultLines() {
473        if (defaultLinesIdx == cacheIdx)
474            return defaultLines;
475        defaultLines = fromCanvas("default-lines", Boolean.TRUE, Boolean.class);
476        defaultLinesIdx = cacheIdx;
477        return defaultLines;
478    }
479
480    private <T> T fromCanvas(String key, T def, Class<T> c) {
481        MultiCascade mc = new MultiCascade();
482        Relation r = new Relation();
483        r.put("#canvas", "query");
484
485        for (StyleSource s : styleSources) {
486            if (s.active) {
487                s.apply(mc, r, 1, false);
488            }
489        }
490        return mc.getCascade("default").get(key, def, c);
491    }
492
493    /**
494     * Determines whether multipolygons must be drawn.
495     * @return whether multipolygons must be drawn.
496     */
497    public boolean isDrawMultipolygon() {
498        return drawMultipolygon;
499    }
500
501    /**
502     * Sets whether multipolygons must be drawn.
503     * @param drawMultipolygon whether multipolygons must be drawn
504     */
505    public void setDrawMultipolygon(boolean drawMultipolygon) {
506        this.drawMultipolygon = drawMultipolygon;
507    }
508
509    /**
510     * remove all style sources; only accessed from MapPaintStyles
511     */
512    void clear() {
513        styleSources.clear();
514    }
515
516    /**
517     * add a style source; only accessed from MapPaintStyles
518     * @param style style source to add
519     */
520    void add(StyleSource style) {
521        styleSources.add(Objects.requireNonNull(style));
522    }
523
524    /**
525     * remove a style source; only accessed from MapPaintStyles
526     * @param style style source to remove
527     * @return {@code true} if this list contained the specified element
528     */
529    boolean remove(StyleSource style) {
530        return styleSources.remove(Objects.requireNonNull(style));
531    }
532
533    /**
534     * set the style sources; only accessed from MapPaintStyles
535     * @param sources new style sources
536     */
537    void setStyleSources(Collection<StyleSource> sources) {
538        styleSources.clear();
539        sources.forEach(this::add);
540    }
541
542    /**
543     * Returns the first AreaElement for a given primitive.
544     * @param p the OSM primitive
545     * @param pretendWayIsClosed For styles that require the way to be closed,
546     * we pretend it is. This is useful for generating area styles from the (segmented)
547     * outer ways of a multipolygon.
548     * @return first AreaElement found or {@code null}.
549     * @since 13810 (signature)
550     */
551    public static AreaElement getAreaElemStyle(IPrimitive p, boolean pretendWayIsClosed) {
552        MapCSSStyleSource.STYLE_SOURCE_LOCK.readLock().lock();
553        try {
554            if (MapPaintStyles.getStyles() == null)
555                return null;
556            for (StyleElement s : MapPaintStyles.getStyles().generateStyles(p, 1.0, pretendWayIsClosed).a) {
557                if (s instanceof AreaElement)
558                    return (AreaElement) s;
559            }
560            return null;
561        } finally {
562            MapCSSStyleSource.STYLE_SOURCE_LOCK.readLock().unlock();
563        }
564    }
565
566    /**
567     * Determines whether primitive has an AreaElement.
568     * @param p the OSM primitive
569     * @param pretendWayIsClosed For styles that require the way to be closed,
570     * we pretend it is. This is useful for generating area styles from the (segmented)
571     * outer ways of a multipolygon.
572     * @return {@code true} if primitive has an AreaElement
573     * @since 13810 (signature)
574     */
575    public static boolean hasAreaElemStyle(IPrimitive p, boolean pretendWayIsClosed) {
576        return getAreaElemStyle(p, pretendWayIsClosed) != null;
577    }
578
579    /**
580     * Determines whether primitive has area-type {@link StyleElement}s, but
581     * no line-type StyleElements.
582     *
583     * {@link TextElement} is ignored, as it can be both line and area-type.
584     * @param p the OSM primitive
585     * @return {@code true} if primitive has area elements, but no line elements
586     * @since 12700
587     * @since 13810 (signature)
588     */
589    public static boolean hasOnlyAreaElements(IPrimitive p) {
590        MapCSSStyleSource.STYLE_SOURCE_LOCK.readLock().lock();
591        try {
592            if (MapPaintStyles.getStyles() == null)
593                return false;
594            StyleElementList styles = MapPaintStyles.getStyles().generateStyles(p, 1.0, false).a;
595            boolean hasAreaElement = false;
596            for (StyleElement s : styles) {
597                if (s instanceof TextElement) {
598                    continue;
599                }
600                if (s instanceof AreaElement) {
601                    hasAreaElement = true;
602                } else {
603                    return false;
604                }
605            }
606            return hasAreaElement;
607        } finally {
608            MapCSSStyleSource.STYLE_SOURCE_LOCK.readLock().unlock();
609        }
610    }
611
612    /**
613     * Looks up a preference value and ensures the style cache is invalidated
614     * as soon as this preference value is changed by the user.
615     *
616     * In addition, it adds an intermediate cache for the preference values,
617     * as frequent preference lookup (using <code>Config.getPref().get()</code>) for
618     * each primitive can be slow during rendering.
619     *
620     * If the default value can be {@linkplain Cascade#convertTo converted} to a {@link Color},
621     * the {@link NamedColorProperty} is retrieved as string.
622     *
623     * @param source style source
624     * @param key preference key
625     * @param def default value
626     * @return the corresponding preference value
627     * @see org.openstreetmap.josm.data.Preferences#get(String, String)
628     */
629    public String getPreferenceCached(StyleSource source, String key, String def) {
630        String res;
631        if (preferenceCache.containsKey(key)) {
632            res = preferenceCache.get(key);
633        } else {
634            Color realDef = Cascade.convertTo(def, Color.class);
635            if (realDef != null) {
636                String prefName = source != null ? source.getFileNamePart() : "unknown";
637                NamedColorProperty property = new NamedColorProperty(NamedColorProperty.COLOR_CATEGORY_MAPPAINT, prefName, key, realDef);
638                res = ColorHelper.color2html(property.get());
639            } else {
640                res = Config.getPref().get(key, null);
641            }
642            preferenceCache.put(key, res);
643        }
644        return res != null ? res : def;
645    }
646
647    @Override
648    public void preferenceChanged(PreferenceChangeEvent e) {
649        if (preferenceCache.containsKey(e.getKey())) {
650            clearCached();
651        }
652    }
653}