001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.data.osm.visitor.paint.relations;
003
004import java.util.ArrayList;
005import java.util.Collection;
006import java.util.HashMap;
007import java.util.Iterator;
008import java.util.List;
009import java.util.Map;
010
011import org.openstreetmap.josm.Main;
012import org.openstreetmap.josm.data.SelectionChangedListener;
013import org.openstreetmap.josm.data.osm.DataSet;
014import org.openstreetmap.josm.data.osm.Node;
015import org.openstreetmap.josm.data.osm.OsmPrimitive;
016import org.openstreetmap.josm.data.osm.Relation;
017import org.openstreetmap.josm.data.osm.Way;
018import org.openstreetmap.josm.data.osm.event.AbstractDatasetChangedEvent;
019import org.openstreetmap.josm.data.osm.event.DataChangedEvent;
020import org.openstreetmap.josm.data.osm.event.DataSetListener;
021import org.openstreetmap.josm.data.osm.event.NodeMovedEvent;
022import org.openstreetmap.josm.data.osm.event.PrimitivesAddedEvent;
023import org.openstreetmap.josm.data.osm.event.PrimitivesRemovedEvent;
024import org.openstreetmap.josm.data.osm.event.RelationMembersChangedEvent;
025import org.openstreetmap.josm.data.osm.event.TagsChangedEvent;
026import org.openstreetmap.josm.data.osm.event.WayNodesChangedEvent;
027import org.openstreetmap.josm.data.osm.visitor.paint.relations.Multipolygon.PolyData;
028import org.openstreetmap.josm.data.projection.Projection;
029import org.openstreetmap.josm.data.projection.ProjectionChangeListener;
030import org.openstreetmap.josm.gui.MapView;
031import org.openstreetmap.josm.gui.MapView.LayerChangeListener;
032import org.openstreetmap.josm.gui.NavigatableComponent;
033import org.openstreetmap.josm.gui.layer.Layer;
034import org.openstreetmap.josm.gui.layer.OsmDataLayer;
035
036/**
037 * A memory cache for {@link Multipolygon} objects.
038 * @since 4623
039 */
040public final class MultipolygonCache implements DataSetListener, LayerChangeListener, ProjectionChangeListener, SelectionChangedListener {
041
042    private static final MultipolygonCache INSTANCE = new MultipolygonCache();
043
044    private final Map<NavigatableComponent, Map<DataSet, Map<Relation, Multipolygon>>> cache;
045
046    private final Collection<PolyData> selectedPolyData;
047
048    private MultipolygonCache() {
049        this.cache = new HashMap<>();
050        this.selectedPolyData = new ArrayList<>();
051        Main.addProjectionChangeListener(this);
052        DataSet.addSelectionListener(this);
053        MapView.addLayerChangeListener(this);
054    }
055
056    /**
057     * Replies the unique instance.
058     * @return the unique instance
059     */
060    public static final MultipolygonCache getInstance() {
061        return INSTANCE;
062    }
063
064    /**
065     * Gets a multipolygon from cache.
066     * @param nc The navigatable component
067     * @param r The multipolygon relation
068     * @return A multipolygon object for the given relation, or {@code null}
069     */
070    public final Multipolygon get(NavigatableComponent nc, Relation r) {
071        return get(nc, r, false);
072    }
073
074    /**
075     * Gets a multipolygon from cache.
076     * @param nc The navigatable component
077     * @param r The multipolygon relation
078     * @param forceRefresh if {@code true}, a new object will be created even of present in cache
079     * @return A multipolygon object for the given relation, or {@code null}
080     */
081    public final Multipolygon get(NavigatableComponent nc, Relation r, boolean forceRefresh) {
082        Multipolygon multipolygon = null;
083        if (nc != null && r != null) {
084            Map<DataSet, Map<Relation, Multipolygon>> map1 = cache.get(nc);
085            if (map1 == null) {
086                cache.put(nc, map1 = new HashMap<>());
087            }
088            Map<Relation, Multipolygon> map2 = map1.get(r.getDataSet());
089            if (map2 == null) {
090                map1.put(r.getDataSet(), map2 = new HashMap<>());
091            }
092            multipolygon = map2.get(r);
093            if (multipolygon == null || forceRefresh) {
094                map2.put(r, multipolygon = new Multipolygon(r));
095                for (PolyData pd : multipolygon.getCombinedPolygons()) {
096                    if (pd.selected) {
097                        selectedPolyData.add(pd);
098                    }
099                }
100            }
101        }
102        return multipolygon;
103    }
104
105    /**
106     * Clears the cache for the given navigatable component.
107     * @param nc the navigatable component
108     */
109    public final void clear(NavigatableComponent nc) {
110        Map<DataSet, Map<Relation, Multipolygon>> map = cache.remove(nc);
111        if (map != null) {
112            map.clear();
113            map = null;
114        }
115    }
116
117    /**
118     * Clears the cache for the given dataset.
119     * @param ds the data set
120     */
121    public final void clear(DataSet ds) {
122        for (Map<DataSet, Map<Relation, Multipolygon>> map1 : cache.values()) {
123            Map<Relation, Multipolygon> map2 = map1.remove(ds);
124            if (map2 != null) {
125                map2.clear();
126                map2 = null;
127            }
128        }
129    }
130
131    /**
132     * Clears the whole cache.
133     */
134    public final void clear() {
135        cache.clear();
136    }
137
138    private final Collection<Map<Relation, Multipolygon>> getMapsFor(DataSet ds) {
139        List<Map<Relation, Multipolygon>> result = new ArrayList<>();
140        for (Map<DataSet, Map<Relation, Multipolygon>> map : cache.values()) {
141            Map<Relation, Multipolygon> map2 = map.get(ds);
142            if (map2 != null) {
143                result.add(map2);
144            }
145        }
146        return result;
147    }
148
149    private static final boolean isMultipolygon(OsmPrimitive p) {
150        return p instanceof Relation && ((Relation) p).isMultipolygon();
151    }
152
153    private final void updateMultipolygonsReferringTo(AbstractDatasetChangedEvent event) {
154        updateMultipolygonsReferringTo(event, event.getPrimitives(), event.getDataset());
155    }
156
157    private final void updateMultipolygonsReferringTo(
158            final AbstractDatasetChangedEvent event, Collection<? extends OsmPrimitive> primitives, DataSet ds) {
159        updateMultipolygonsReferringTo(event, primitives, ds, null);
160    }
161
162    private final Collection<Map<Relation, Multipolygon>> updateMultipolygonsReferringTo(
163            AbstractDatasetChangedEvent event, Collection<? extends OsmPrimitive> primitives,
164            DataSet ds, Collection<Map<Relation, Multipolygon>> initialMaps) {
165        Collection<Map<Relation, Multipolygon>> maps = initialMaps;
166        if (primitives != null) {
167            for (OsmPrimitive p : primitives) {
168                if (isMultipolygon(p)) {
169                    if (maps == null) {
170                        maps = getMapsFor(ds);
171                    }
172                    processEvent(event, (Relation) p, maps);
173
174                } else if (p instanceof Way && p.getDataSet() != null) {
175                    for (OsmPrimitive ref : p.getReferrers()) {
176                        if (isMultipolygon(ref)) {
177                            if (maps == null) {
178                                maps = getMapsFor(ds);
179                            }
180                            processEvent(event, (Relation) ref, maps);
181                        }
182                    }
183                } else if (p instanceof Node && p.getDataSet() != null) {
184                    maps = updateMultipolygonsReferringTo(event, p.getReferrers(), ds, maps);
185                }
186            }
187        }
188        return maps;
189    }
190
191    private final void processEvent(AbstractDatasetChangedEvent event, Relation r, Collection<Map<Relation, Multipolygon>> maps) {
192        if (event instanceof NodeMovedEvent || event instanceof WayNodesChangedEvent) {
193            dispatchEvent(event, r, maps);
194        } else if (event instanceof PrimitivesRemovedEvent) {
195            if (event.getPrimitives().contains(r)) {
196                removeMultipolygonFrom(r, maps);
197            }
198        } else {
199            // Default (non-optimal) action: remove multipolygon from cache
200            removeMultipolygonFrom(r, maps);
201        }
202    }
203
204    private final void dispatchEvent(AbstractDatasetChangedEvent event, Relation r, Collection<Map<Relation, Multipolygon>> maps) {
205        for (Map<Relation, Multipolygon> map : maps) {
206            Multipolygon m = map.get(r);
207            if (m != null) {
208                for (PolyData pd : m.getCombinedPolygons()) {
209                    if (event instanceof NodeMovedEvent) {
210                        pd.nodeMoved((NodeMovedEvent) event);
211                    } else if (event instanceof WayNodesChangedEvent) {
212                        pd.wayNodesChanged((WayNodesChangedEvent)event);
213                    }
214                }
215            }
216        }
217    }
218
219    private final void removeMultipolygonFrom(Relation r, Collection<Map<Relation, Multipolygon>> maps) {
220        for (Map<Relation, Multipolygon> map : maps) {
221            map.remove(r);
222        }
223    }
224
225    @Override
226    public void primitivesAdded(PrimitivesAddedEvent event) {
227        // Do nothing
228    }
229
230    @Override
231    public void primitivesRemoved(PrimitivesRemovedEvent event) {
232        updateMultipolygonsReferringTo(event);
233    }
234
235    @Override
236    public void tagsChanged(TagsChangedEvent event) {
237        // Do nothing
238    }
239
240    @Override
241    public void nodeMoved(NodeMovedEvent event) {
242        updateMultipolygonsReferringTo(event);
243    }
244
245    @Override
246    public void wayNodesChanged(WayNodesChangedEvent event) {
247        updateMultipolygonsReferringTo(event);
248    }
249
250    @Override
251    public void relationMembersChanged(RelationMembersChangedEvent event) {
252        updateMultipolygonsReferringTo(event);
253    }
254
255    @Override
256    public void otherDatasetChange(AbstractDatasetChangedEvent event) {
257        // Do nothing
258    }
259
260    @Override
261    public void dataChanged(DataChangedEvent event) {
262        // Do not call updateMultipolygonsReferringTo as getPrimitives()
263        // can return all the data set primitives for this event
264        Collection<Map<Relation, Multipolygon>> maps = null;
265        for (OsmPrimitive p : event.getPrimitives()) {
266            if (isMultipolygon(p)) {
267                if (maps == null) {
268                    maps = getMapsFor(event.getDataset());
269                }
270                for (Map<Relation, Multipolygon> map : maps) {
271                    // DataChangedEvent is sent after downloading incomplete members (see #7131),
272                    // without having received RelationMembersChangedEvent or PrimitivesAddedEvent
273                    // OR when undoing a move of a large number of nodes (see #7195),
274                    // without having received NodeMovedEvent
275                    // This ensures concerned multipolygons will be correctly redrawn
276                    map.remove(p);
277                }
278            }
279        }
280    }
281
282    @Override
283    public void activeLayerChange(Layer oldLayer, Layer newLayer) {
284        // Do nothing
285    }
286
287    @Override
288    public void layerAdded(Layer newLayer) {
289        // Do nothing
290    }
291
292    @Override
293    public void layerRemoved(Layer oldLayer) {
294        if (oldLayer instanceof OsmDataLayer) {
295            clear(((OsmDataLayer) oldLayer).data);
296        }
297    }
298
299    @Override
300    public void projectionChanged(Projection oldValue, Projection newValue) {
301        clear();
302    }
303
304    @Override
305    public void selectionChanged(Collection<? extends OsmPrimitive> newSelection) {
306
307        for (Iterator<PolyData> it = selectedPolyData.iterator(); it.hasNext();) {
308            it.next().selected = false;
309            it.remove();
310        }
311
312        DataSet ds = null;
313        Collection<Map<Relation, Multipolygon>> maps = null;
314        for (OsmPrimitive p : newSelection) {
315            if (p instanceof Way && p.getDataSet() != null) {
316                if (ds == null) {
317                    ds = p.getDataSet();
318                }
319                for (OsmPrimitive ref : p.getReferrers()) {
320                    if (isMultipolygon(ref)) {
321                        if (maps == null) {
322                            maps = getMapsFor(ds);
323                        }
324                        for (Map<Relation, Multipolygon> map : maps) {
325                            Multipolygon multipolygon = map.get(ref);
326                            if (multipolygon != null) {
327                                for (PolyData pd : multipolygon.getCombinedPolygons()) {
328                                    if (pd.getWayIds().contains(p.getUniqueId())) {
329                                        pd.selected = true;
330                                        selectedPolyData.add(pd);
331                                    }
332                                }
333                            }
334                        }
335                    }
336                }
337            }
338        }
339    }
340}