001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.data.osm;
003
004import java.util.Collection;
005import java.util.Objects;
006import java.util.Set;
007import java.util.stream.Collectors;
008import java.util.stream.IntStream;
009
010/**
011 * This is an extension of {@link RelationMember} that stores the parent relation and the index in it in addition to the role/child.
012 */
013public class RelationToChildReference {
014
015    /**
016     * Replies a set of all {@link RelationToChildReference}s for a given child primitive.
017     *
018     * @param child the child primitive
019     * @return  a set of all {@link RelationToChildReference}s for a given child primitive
020     */
021    public static Set<RelationToChildReference> getRelationToChildReferences(OsmPrimitive child) {
022        Set<Relation> parents = child.referrers(Relation.class).collect(Collectors.toSet());
023        return parents.stream().flatMap(parent1 -> IntStream.range(0, parent1.getMembersCount())
024                .filter(i -> parent1.getMember(i).refersTo(child))
025                .mapToObj(i -> new RelationToChildReference(parent1, i, parent1.getMember(i))))
026                .collect(Collectors.toSet());
027    }
028
029    /**
030     * Replies a set of all {@link RelationToChildReference}s for a collection of child primitives
031     *
032     * @param children the collection of child primitives
033     * @return  a set of all {@link RelationToChildReference}s to the children in the collection of child
034     * primitives
035     */
036    public static Set<RelationToChildReference> getRelationToChildReferences(Collection<? extends OsmPrimitive> children) {
037        return children.stream()
038                .flatMap(child -> getRelationToChildReferences(child).stream())
039                .collect(Collectors.toSet());
040    }
041
042    private final Relation parent;
043    private final int position;
044    private final String role;
045    private final OsmPrimitive child;
046
047    /**
048     * Create a new {@link RelationToChildReference}
049     * @param parent The parent relation
050     * @param position The position of the child in the parent
051     * @param role The role of the child
052     * @param child The actual child (member of parent)
053     */
054    public RelationToChildReference(Relation parent, int position, String role, OsmPrimitive child) {
055        this.parent = parent;
056        this.position = position;
057        this.role = role;
058        this.child = child;
059    }
060
061    /**
062     * Create a new {@link RelationToChildReference}
063     * @param parent The parent relation
064     * @param position The position of the child in the parent
065     * @param member The role and relation for the child
066     */
067    public RelationToChildReference(Relation parent, int position, RelationMember member) {
068        this(parent, position, member.getRole(), member.getMember());
069    }
070
071    /**
072     * Get the parent relation
073     * @return The parent
074     */
075    public Relation getParent() {
076        return parent;
077    }
078
079    /**
080     * Get the position of the child in the parent
081     * @return The position of the child
082     */
083    public int getPosition() {
084        return position;
085    }
086
087    /**
088     * Get the role of the child
089     * @return The role
090     */
091    public String getRole() {
092        return role;
093    }
094
095    /**
096     * Get the actual child
097     * @return The child
098     */
099    public OsmPrimitive getChild() {
100        return child;
101    }
102
103    @Override
104    public boolean equals(Object obj) {
105        if (this == obj) return true;
106        if (obj == null || getClass() != obj.getClass()) return false;
107        RelationToChildReference that = (RelationToChildReference) obj;
108        return position == that.position &&
109                Objects.equals(parent, that.parent) &&
110                Objects.equals(role, that.role) &&
111                Objects.equals(child, that.child);
112    }
113
114    @Override
115    public int hashCode() {
116        return Objects.hash(parent, position, role, child);
117    }
118}