package org.jsoup.select;
import org.jsoup.nodes.Node;
/**
* Depth-first node traversor. Use to iterate through all nodes under and including the specified root node.
* <p/>
* This implementation does not use recursion, so a deep DOM does not risk blowing the stack.
*/
public class NodeTraversor {
private NodeVisitor visitor;
/**
* Create a new traversor.
* @param visitor a class implementing the {@link NodeVisitor} interface, to be called when visiting each node.
*/
public NodeTraversor(NodeVisitor visitor) {
this.visitor = visitor;
}
/**
* Start a depth-first traverse of the root and all of its descendants.
* @param root the root node point to traverse.
*/
public void traverse(Node root) {
Node node = root;
int depth = 0;
while (node != null) {
visitor.head(node, depth);
if (node.childNodeSize() > 0) {
node = node.childNode(0);
depth++;
} else {
while (node.nextSibling() == null && depth > 0) {
visitor.tail(node, depth);
node = node.parentNode();
depth--;
}
visitor.tail(node, depth);
if (node == root)
break;
node = node.nextSibling();
}
}
}
}