package org.jsoup.select;
import org.jsoup.nodes.Element;
import org.jsoup.nodes.Node;
/**
* Collects a list of elements that match the supplied criteria.
*
* @author Jonathan Hedley
*/
public class Collector {
private Collector() {
}
/**
Build a list of elements, by visiting root and every descendant of root, and testing it against the evaluator.
@param eval Evaluator to test elements against
@param root root of tree to descend
@return list of matches; empty if none
*/
public static Elements collect (Evaluator eval, Element root) {
Elements elements = new Elements();
new NodeTraversor(new Accumulator(root, elements, eval)).traverse(root);
return elements;
}
private static class Accumulator implements NodeVisitor {
private final Element root;
private final Elements elements;
private final Evaluator eval;
Accumulator(Element root, Elements elements, Evaluator eval) {
this.root = root;
this.elements = elements;
this.eval = eval;
}
public void head(Node node, int depth) {
if (node instanceof Element) {
Element el = (Element) node;
if (eval.matches(root, el))
elements.add(el);
}
}
public void tail(Node node, int depth) {
// void
}
}
}
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