From 69febf399bf93977894bdc98d725ba88b5c56941 Mon Sep 17 00:00:00 2001
From: Manolo Carrasco <manolo@apache.org>
Date: Sat, 27 Aug 2011 21:04:49 +0000
Subject: [PATCH] implement has() method

---
 .../com/google/gwt/query/client/GQuery.java   | 27 +++++++++++++++++--
 .../google/gwt/query/client/LazyGQuery.java   | 12 +++++++++
 .../gwt/query/client/impl/SelectorEngine.java |  4 +++
 .../gwt/query/client/GQueryCoreTest.java      | 21 +++++++++++++++
 4 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/gwtquery-core/src/main/java/com/google/gwt/query/client/GQuery.java b/gwtquery-core/src/main/java/com/google/gwt/query/client/GQuery.java
index d9a05ef0..96473dbd 100644
--- a/gwtquery-core/src/main/java/com/google/gwt/query/client/GQuery.java
+++ b/gwtquery-core/src/main/java/com/google/gwt/query/client/GQuery.java
@@ -1864,9 +1864,7 @@ public class GQuery implements Lazy<GQuery, LazyGQuery> {
    * filters at once.
    */
   public GQuery filter(String... filters) {
-
     JsNodeArray array = JsNodeArray.create();
-
     for (String f : filters) {
       for (Element e : elements) {
         boolean ghostParent = false;
@@ -1993,6 +1991,31 @@ public class GQuery implements Lazy<GQuery, LazyGQuery> {
   public GQuery gt(int pos) {
     return $(slice(pos + 1, -1));
   }
+  
+
+  /**
+   * Reduce the set of matched elements to those that have a descendant 
+   * that matches the selector.
+   */
+  public GQuery has(final String selector) {
+    return filter(new Predicate(){
+      public boolean f(Element e, int index) {
+        return !$(selector, e).isEmpty();
+      }
+    });
+  }
+
+  /**
+   * Reduce the set of matched elements to those that have a descendant 
+   * that matches the Element.
+   */
+  public GQuery has(final Element elem) {
+    return filter(new Predicate(){
+      public boolean f(Element e, int index) {
+        return engine.contains(e, elem);
+      }
+    });
+  }
 
   /**
    * Returns true any of the specified classes are present on any of the matched
diff --git a/gwtquery-core/src/main/java/com/google/gwt/query/client/LazyGQuery.java b/gwtquery-core/src/main/java/com/google/gwt/query/client/LazyGQuery.java
index dfa090fa..b2d1d37e 100644
--- a/gwtquery-core/src/main/java/com/google/gwt/query/client/LazyGQuery.java
+++ b/gwtquery-core/src/main/java/com/google/gwt/query/client/LazyGQuery.java
@@ -1082,6 +1082,18 @@ public interface LazyGQuery<T> extends LazyBase<T>{
    */
   LazyGQuery<T> gt(int pos);
 
+  /**
+   * Reduce the set of matched elements to those that have a descendant 
+   * that matches the selector.
+   */
+  LazyGQuery<T> has(String selector);
+
+  /**
+   * Reduce the set of matched elements to those that have a descendant 
+   * that matches the Element.
+   */
+  LazyGQuery<T> has(Element elem);
+
   /**
    * Returns true any of the specified classes are present on any of the matched
    * elements.
diff --git a/gwtquery-core/src/main/java/com/google/gwt/query/client/impl/SelectorEngine.java b/gwtquery-core/src/main/java/com/google/gwt/query/client/impl/SelectorEngine.java
index c013a226..46de0000 100644
--- a/gwtquery-core/src/main/java/com/google/gwt/query/client/impl/SelectorEngine.java
+++ b/gwtquery-core/src/main/java/com/google/gwt/query/client/impl/SelectorEngine.java
@@ -139,6 +139,10 @@ public class SelectorEngine implements HasSelector {
     }
   }
   
+  public native boolean contains(Element a, Element b) /*-{
+    return a.contains ? a != b && a.contains(b) : !!(a.compareDocumentPosition(b) & 16)
+  }-*/;
+  
   public void setRoot(Node root) {
     assert root != null;
     this.root = root;
diff --git a/gwtquery-core/src/test/java/com/google/gwt/query/client/GQueryCoreTest.java b/gwtquery-core/src/test/java/com/google/gwt/query/client/GQueryCoreTest.java
index b7632fd3..b7cd195c 100644
--- a/gwtquery-core/src/test/java/com/google/gwt/query/client/GQueryCoreTest.java
+++ b/gwtquery-core/src/test/java/com/google/gwt/query/client/GQueryCoreTest.java
@@ -1744,5 +1744,26 @@ public class GQueryCoreTest extends GWTTestCase {
     test.addClass("test");
     test.removeClass("test");
   }
+  
+  public void testHas() {
+    $(e).html("<ul>"
+              +"<li>list item 1</li>"
+              +"<li id='l2'>list item 2"
+              +" <ul>"
+              +"  <li>list item 2-a</li>"
+              +"  <li>list item 2-b</li>"
+              +" </ul>"
+              +"</li>"
+              +"<li id='l3'>list item 3 <span>span</span>" 
+              +"</li>"
+              +"<li>list item 4</li>"
+              +"</ul>");
+    assertEquals("", $("#l2").css("background-color"));
+    $("li", e).has("ul").css("background-color", "red");
+    assertEquals("red", $("#l2").css("background-color"));
+
+    Element span = $("span", e).get(0);
+    assertEquals("l3", $("li", e).has(span).id());
+  }
 
 }
-- 
2.39.5