Add Event delegation to Elements and groups of elements.

tests/html/element_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library ElementTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_individual_config.dart';
 import 'dart:async';
 import 'dart:html';
 import 'dart:svg' as svg;
@@ skipping 267 matching lines @@
   group('click', () {
     test('clickEvent', () {
       var e = new DivElement();
       var firedEvent = false;
       e.onClick.listen((event) {
         firedEvent = true;
       });
       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);
     });
   });
 
   group('attributes', () {
       test('manipulation', () {
         final element = new Element.html(
             '''<div class="foo" style="overflow: hidden" data-foo="bar"
                    data-foo2="bar2" dir="rtl">
                </div>''');
         final attributes = element.attributes;
@@ skipping 423 matching lines @@
       expect(filtered, isElementIterable);
     });
 
     test('sublist', () {
       var range = makeElList().sublist(1, 3);
       expect(range, isElementList);
       expect(range[0], isImageElement);
       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);
+    });
+  });
 }