Add Event delegation to Elements and groups of elements.

tests/html/element_test.dart

Index: tests/html/element_test.dart
diff --git a/tests/html/element_test.dart b/tests/html/element_test.dart
index 7e137419a1317a5691d198ce6897c32a5e5872c4..c053a8cc2c877cd44e2172e8789d0eab62cd39a8 100644
--- a/tests/html/element_test.dart
+++ b/tests/html/element_test.dart
@@ -285,6 +285,17 @@ main() {
       expect(firedEvent, false);
       e.click();
       expect(firedEvent, true);
+
+      var e2 = new DivElement();
+      var firedEvent2 = false;
+      e2.onClick.filter('.foo').listen((event) {
+        firedEvent2 = true;
+      });
+      e2.click();
+      expect(firedEvent2, false);
+      e2.classes.add('foo');
+      e2.click();
+      expect(firedEvent2, true);
     });
   });
 
@@ -728,4 +739,68 @@ main() {
       expect(range[1], isInputElement);
     });
   });
+
+  group('eventDelegation', () {
+    test('filter', () {
+      Element elem = new Element.div()..classes.addAll(['a', 'b']);
+      Element img = new Element.img()
+        ..classes.addAll(['b', 'a', 'd'])
+        ..id = 'cookie';
+      Element input = new InputElement()..classes.addAll(['c', 'd']);
+      var div = new Element.div()
+        ..classes.add('a')
+        ..id = 'wat';
+      document.body.append(elem);
+      document.body.append(img);
+      document.body.append(input);
+      document.body.append(div);
+
+      var firedEvent = false;
+      var elems = queryAll('.a');
+      queryAll('.a').onClick.listen((event) {
+        firedEvent = true;
+      });
+      expect(firedEvent, false);
+      query('.c').click();
+      expect(firedEvent, false);
+      query('#wat').click();
+      expect(firedEvent, true);
+
+      var firedEvent4 = false;
+      queryAll('.a').onClick.filter('.d').listen((event) {
+        firedEvent4 = true;
+      });
+      expect(firedEvent4, false);
+      query('.c').click();
+      expect(firedEvent4, false);
+      query('#wat').click();
+      expect(firedEvent4, false);
+      query('#cookie').click();
+      expect(firedEvent4, true);
+
+      var firedEvent2 = false;
+      queryAll('.a').onClick.listen((event) {
+        firedEvent2 = true;
+      });
+      Element elem2 = new Element.html('<div class="a"><br/>');
+      document.body.append(elem2);
+      elem2.click();
+      expect(firedEvent2, false);
+      elem2.classes.add('a');
+      elem2.click();
+      expect(firedEvent2, false);
+
+      var firedEvent3 = false;
+      queryAll(':root').onClick.filter('.a').listen((event) {
+        firedEvent3 = true;
+      });
+      Element elem3 = new Element.html('<div class="d"><br/>');
+      document.body.append(elem3);
+      elem3.click();
+      expect(firedEvent3, false);
+      elem3.classes.add('a');
+      elem3.click();
+      expect(firedEvent3, true);
+    });
+  });
 }