package com.tinkerpop.blueprints.util;
import com.tinkerpop.blueprints.Direction;
import com.tinkerpop.blueprints.Edge;
import com.tinkerpop.blueprints.Vertex;
import java.util.Iterator;
/**
* VerticesFromEdgesIterable is a helper class that returns vertices that meet the direction/label criteria of the incident edges.
*
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
public class VerticesFromEdgesIterable implements Iterable<Vertex> {
private final Iterable<Edge> iterable;
private final Direction direction;
private final Vertex vertex;
public VerticesFromEdgesIterable(final Vertex vertex, final Direction direction, final String... labels) {
this.direction = direction;
this.vertex = vertex;
this.iterable = vertex.getEdges(direction, labels);
}
public Iterator<Vertex> iterator() {
return new Iterator<Vertex>() {
final Iterator<Edge> itty = iterable.iterator();
public void remove() {
this.itty.remove();
}
public boolean hasNext() {
return this.itty.hasNext();
}
public Vertex next() {
if (direction.equals(Direction.OUT)) {
return this.itty.next().getVertex(Direction.IN);
} else if (direction.equals(Direction.IN)) {
return this.itty.next().getVertex(Direction.OUT);
} else {
final Edge edge = this.itty.next();
if (edge.getVertex(Direction.IN).equals(vertex))
return edge.getVertex(Direction.OUT);
else
return edge.getVertex(Direction.IN);
}
}
};
}
}