001    /*
002     * JBoss DNA (http://www.jboss.org/dna)
003     * See the COPYRIGHT.txt file distributed with this work for information
004     * regarding copyright ownership.  Some portions may be licensed
005     * to Red Hat, Inc. under one or more contributor license agreements.
006     * See the AUTHORS.txt file in the distribution for a full listing of 
007     * individual contributors. 
008     *
009     * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
010     * is licensed to you under the terms of the GNU Lesser General Public License as
011     * published by the Free Software Foundation; either version 2.1 of
012     * the License, or (at your option) any later version.
013     *
014     * JBoss DNA is distributed in the hope that it will be useful,
015     * but WITHOUT ANY WARRANTY; without even the implied warranty of
016     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017     * Lesser General Public License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this software; if not, write to the Free
021     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
022     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
023     */
024    package org.jboss.dna.graph;
025    
026    import net.jcip.annotations.Immutable;
027    import org.jboss.dna.graph.property.Name;
028    import org.jboss.dna.graph.property.Path;
029    
030    /**
031     * A subgraph returned by the {@link Graph}, containing the nodes in the subgraph as well as the properties and children for each
032     * of those nodes. The {@link #iterator()} method may be used to walk the nodes in the subgraph in a pre-order traversal.
033     * <p>
034     * Since this subgraph has a single {@link #getLocation() node that is the top of the subgraph}, the methods that take a String
035     * path or {@link Path path object} will accept absolute or relative paths.
036     * </p>
037     * <p>
038     * This subgraph will not contain any {@link #iterator() nodes} that exist below the {@link #getMaximumDepth() maximum depth}.
039     * Also, all nodes included in the subgraph have all their properties and children. However, nodes that are at the maximum depth
040     * of the subgraph will contain the locations for child nodes that are below the maximum depth and therefore not included in this
041     * subgraph.
042     * </p>
043     * 
044     * @author Randall Hauch
045     */
046    @Immutable
047    public interface Subgraph extends Graph.BaseResults<SubgraphNode> {
048    
049        /**
050         * Get the location of the subgraph, which is the location of the node at the top of the subgraph.
051         * 
052         * @return the location of the top node in the subgraph; never null
053         */
054        Location getLocation();
055    
056        /**
057         * Get the maximum depth requested for this subgraph. The actual subgraph may not be as deep, but will never be deeper than
058         * this value.
059         * 
060         * @return the maximum depth requested; always positive
061         */
062        int getMaximumDepth();
063    
064        /**
065         * Get the node at the supplied location.
066         * 
067         * @param relativePath the name that makes up a relative path to the node that is an immediate child of the {@link #getRoot()
068         *        root}
069         * @return the node, or null if the node is not {@link #includes(Path) included} in these results
070         */
071        SubgraphNode getNode( Name relativePath );
072    
073        /**
074         * Get the node that is at the {@link #getLocation() root} of the subgraph.
075         * 
076         * @return the root node in the subgraph
077         */
078        SubgraphNode getRoot();
079    
080    }