/**
* BSD-style license; for more info see http://pmd.sourceforge.net/license.html
*/
package net.sourceforge.pmd.lang.ast.xpath;
import java.util.Iterator;
import java.util.NoSuchElementException;
import net.sourceforge.pmd.lang.ast.Node;
/**
* @author daniels
*/
public abstract class NodeIterator implements Iterator<Node> {
private Node node;
public NodeIterator(Node contextNode) {
this.node = getFirstNode(contextNode);
}
@Override
public boolean hasNext() {
return node != null;
}
@Override
public Node next() {
if (node == null) {
throw new NoSuchElementException();
}
Node ret = node;
node = getNextNode(node);
return ret;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
protected abstract Node getFirstNode(Node contextNode);
protected abstract Node getNextNode(Node contextNode);
protected Node getPreviousSibling(Node contextNode) {
Node parentNode = contextNode.jjtGetParent();
if (parentNode != null) {
int prevPosition = contextNode.jjtGetChildIndex() - 1;
if (prevPosition >= 0) {
return parentNode.jjtGetChild(prevPosition);
}
}
return null;
}
protected Node getNextSibling(Node contextNode) {
Node parentNode = contextNode.jjtGetParent();
if (parentNode != null) {
int nextPosition = contextNode.jjtGetChildIndex() + 1;
if (nextPosition < parentNode.jjtGetNumChildren()) {
return parentNode.jjtGetChild(nextPosition);
}
}
return null;
}
protected Node getFirstChild(Node contextNode) {
if (contextNode.jjtGetNumChildren() > 0) {
return contextNode.jjtGetChild(0);
} else {
return null;
}
}
protected Node getLastChild(Node contextNode) {
if (contextNode.jjtGetNumChildren() > 0) {
return contextNode.jjtGetChild(contextNode.jjtGetNumChildren() - 1);
} else {
return null;
}
}
}