DescendantIterator.java

/*
Copyright 2008-2010 Gephi
Authors : Mathieu Bastian <mathieu.bastian@gephi.org>
Website : http://www.gephi.org

This file is part of Gephi.

DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

Copyright 2011 Gephi Consortium. All rights reserved.

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"License"). You may not use this file except in compliance with the
License. You can obtain a copy of the License at
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or /cddl-1.0.txt and /gpl-3.0.txt. See the License for the
specific language governing permissions and limitations under the
License.  When distributing the software, include this License Header
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*/
package org.gephi.graph.dhns.node.iterators;

import java.util.Iterator;
import org.gephi.graph.dhns.core.DurableTreeList;
import org.gephi.graph.dhns.core.TreeStructure;
import org.gephi.utils.collection.avl.ResetableIterator;
import org.gephi.graph.api.Node;
import org.gephi.graph.dhns.core.DurableTreeList.DurableAVLNode;
import org.gephi.graph.dhns.node.AbstractNode;
import org.gephi.graph.dhns.predicate.Predicate;

/**
 * {@link AbstractNode} iterator for descendant of a node or the whole structure.
 *
 * @author Mathieu Bastian
 * @see ChildrenIterator
 */
public class DescendantIterator extends AbstractNodeIterator implements Iterator<Node>, ResetableIterator {

    protected int treeSize;
    protected DurableTreeList treeList;
    protected int nextIndex;
    protected int diffIndex;
    protected DurableAVLNode currentNode;
    protected boolean loopStart = true;

    //Proposition
    protected Predicate<AbstractNode> predicate;

    public DescendantIterator(TreeStructure treeStructure, Predicate<AbstractNode> predicate) {
        this.treeList = treeStructure.getTree();
        nextIndex = 0;
        diffIndex = 2;
        treeSize = treeList.size();
        this.predicate = predicate;
    }

    public DescendantIterator(TreeStructure treeStructure, AbstractNode node, Predicate<AbstractNode> proposition) {
        this(treeStructure, proposition);
        setNode(node);
    }

    public void setNode(AbstractNode node) {
        nextIndex = node.getPre() + 1;
        treeSize = node.getPre() + node.size + 1;
        diffIndex = 2;
    }

    public boolean hasNext() {
        while (loopStart || !predicate.evaluate(currentNode.getValue())) {

            if (!loopStart) {
                nextIndex = currentNode.getValue().getPre() + 1 + currentNode.getValue().size;
                diffIndex = nextIndex - currentNode.getValue().pre;
            }
            loopStart = false;

            if (nextIndex < treeSize) {
                if (diffIndex > 1) {
                    currentNode = treeList.getNode(nextIndex);
                } else {
                    currentNode = currentNode.next();
                }
            } else {
                return false;
            }
        }
        return true;
    }

    public AbstractNode next() {
        nextIndex++;
        diffIndex = 1;
        loopStart = true;
        return currentNode.getValue();
    }

    public void remove() {
        throw new UnsupportedOperationException();
    }
}