1 files changed, 51 insertions, 0 deletions
diff --git a/src/org/jsoup/select/Collector.java b/src/org/jsoup/select/Collector.java
new file mode 100644
index 0000000000..8f01045768
--- /dev/null
+++ b/src/org/jsoup/select/Collector.java
@@ -0,0 +1,51 @@
+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
+        }
+    }
+}