001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.data.osm.visitor;
003
004import java.util.ArrayList;
005import java.util.HashMap;
006import java.util.List;
007import java.util.Map;
008
009import org.openstreetmap.josm.data.osm.DataSet;
010import org.openstreetmap.josm.data.osm.Node;
011import org.openstreetmap.josm.data.osm.NodeData;
012import org.openstreetmap.josm.data.osm.OsmPrimitive;
013import org.openstreetmap.josm.data.osm.PrimitiveData;
014import org.openstreetmap.josm.data.osm.Relation;
015import org.openstreetmap.josm.data.osm.RelationData;
016import org.openstreetmap.josm.data.osm.RelationMember;
017import org.openstreetmap.josm.data.osm.RelationMemberData;
018import org.openstreetmap.josm.data.osm.Way;
019import org.openstreetmap.josm.data.osm.WayData;
020import org.openstreetmap.josm.tools.CheckParameterUtil;
021
022/**
023 * MergeSourceBuildingVisitor helps to build the "hull" of a collection of {@link OsmPrimitive}s
024 * which shall be merged into another layer. The "hull" is slightly bigger than the original
025 * collection. It includes, for instance the nodes of a way in the original collection even though
026 * these nodes might not be present explicitly in the original collection. The "hull" also includes
027 * incomplete {@link OsmPrimitive}s which are referred to by relations in the original collection. And
028 * it turns {@link OsmPrimitive} referred to by {@link Relation}s in the original collection into
029 * incomplete {@link OsmPrimitive}s in the "hull", if they are not themselves present in the
030 * original collection.
031 *
032 */
033public class MergeSourceBuildingVisitor extends AbstractVisitor {
034    private final DataSet selectionBase;
035    private final DataSet hull;
036    private final Map<OsmPrimitive, PrimitiveData> mappedPrimitives;
037
038    /**
039     * Creates the visitor. The visitor starts to build the "hull" from
040     * the currently selected primitives in the dataset <code>selectionBase</code>,
041     * i.e. from {@link DataSet#getSelected()}.
042     *
043     * @param selectionBase the dataset. Must not be null.
044     * @throws IllegalArgumentException if selectionBase is null
045     */
046    public MergeSourceBuildingVisitor(DataSet selectionBase) {
047        CheckParameterUtil.ensureParameterNotNull(selectionBase, "selectionBase");
048        this.selectionBase = selectionBase;
049        this.hull = new DataSet();
050        this.mappedPrimitives = new HashMap<>();
051    }
052
053    protected boolean isInSelectionBase(OsmPrimitive primitive) {
054        return selectionBase.getAllSelected().contains(primitive);
055    }
056
057    protected boolean isAlreadyRemembered(OsmPrimitive primitive) {
058        return mappedPrimitives.keySet().contains(primitive);
059    }
060
061    /**
062     * Remebers a node in the "hull"
063     *
064     * @param n the node
065     */
066    protected void rememberNode(Node n) {
067        if (isAlreadyRemembered(n))
068            return;
069        mappedPrimitives.put(n, n.save());
070    }
071
072    /**
073     * remembers a way in the hull
074     *
075     * @param w the way
076     */
077    protected void rememberWay(Way w) {
078        if (isAlreadyRemembered(w))
079            return;
080        WayData clone = w.save();
081        List<Long> newNodes = new ArrayList<>(w.getNodesCount());
082        for (Node n: w.getNodes()) {
083            newNodes.add(mappedPrimitives.get(n).getUniqueId());
084        }
085        clone.setNodes(newNodes);
086        mappedPrimitives.put(w, clone);
087    }
088
089    /**
090     * Remembers a relation in the hull
091     *
092     * @param r the relation
093     */
094    protected void rememberRelation(Relation r) {
095        RelationData clone;
096        if (isAlreadyRemembered(r)) {
097            clone = (RelationData) mappedPrimitives.get(r);
098        } else {
099            clone = r.save();
100            mappedPrimitives.put(r, clone);
101        }
102
103        List<RelationMemberData> newMembers = new ArrayList<>();
104        for (RelationMember member: r.getMembers()) {
105            newMembers.add(
106                    new RelationMemberData(member.getRole(), mappedPrimitives.get(member.getMember())));
107
108        }
109        clone.setMembers(newMembers);
110    }
111
112    protected void rememberRelationPartial(Relation r) {
113        if (isAlreadyRemembered(r))
114            return;
115        RelationData clone = r.save();
116        clone.getMembers().clear();
117        mappedPrimitives.put(r, clone);
118    }
119
120    protected void rememberIncomplete(OsmPrimitive primitive) {
121        if (isAlreadyRemembered(primitive))
122            return;
123        PrimitiveData clone = primitive.save();
124        clone.setIncomplete(true);
125        mappedPrimitives.put(primitive, clone);
126    }
127
128    @Override
129    public void visit(Node n) {
130        rememberNode(n);
131    }
132
133    @Override
134    public void visit(Way w) {
135        // remember all nodes this way refers to ...
136        //
137        for (Node n: w.getNodes()) {
138            n.accept(this);
139        }
140        // ... and the way itself
141        rememberWay(w);
142    }
143
144    @Override
145    public void visit(Relation r) {
146        // first, remember all primitives members refer to (only if necessary, see
147        // below)
148        //
149        rememberRelationPartial(r);
150        for (RelationMember member: r.getMembers()) {
151            if (isAlreadyRemembered(member.getMember())) {
152                // referred primitive already remembered
153                //
154                continue;
155            }
156            if (isInSelectionBase(member.getMember()) || member.getMember().isNew()) {
157                member.getMember().accept(this);
158            } else {
159                rememberIncomplete(member.getMember());
160            }
161        }
162        rememberRelation(r);
163    }
164
165    protected void buildHull() {
166        // Create all primitives first
167        for (PrimitiveData primitive: mappedPrimitives.values()) {
168            OsmPrimitive newPrimitive = hull.getPrimitiveById(primitive);
169            boolean created = newPrimitive == null;
170            if (created) {
171                newPrimitive = primitive.getType().newInstance(primitive.getUniqueId(), true);
172            }
173            if (newPrimitive instanceof Node && !primitive.isIncomplete()) {
174                newPrimitive.load(primitive);
175            }
176            if (created) {
177                hull.addPrimitive(newPrimitive);
178            }
179        }
180        // Then ways and relations
181        for (PrimitiveData primitive : mappedPrimitives.values()) {
182            if (!(primitive instanceof NodeData) && !primitive.isIncomplete()) {
183                hull.getPrimitiveById(primitive).load(primitive);
184            }
185        }
186    }
187
188    public DataSet build() {
189        for (OsmPrimitive primitive: selectionBase.getAllSelected()) {
190            primitive.accept(this);
191        }
192        buildHull();
193        return hull;
194    }
195}