Wrapping leaf nodes in non polymer elements

runtime/observatory/lib/src/elements/nav/notify.dart

+// Copyright (c) 2016, 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.
+
+import 'dart:html';
+import 'dart:async';
+import 'package:observatory/models.dart' as M;
+import 'package:observatory/src/elements/helpers/tag.dart';
+import 'package:observatory/src/elements/helpers/rendering_scheduler.dart';
+import 'package:observatory/src/elements/nav/notify_event.dart';
+import 'package:observatory/src/elements/nav/notify_exception.dart';
+
+class NavNotifyElement extends HtmlElement implements Renderable {
+  static const tag = const Tag<NavNotifyElement>('nav-notify-wrapped',
+          dependencies: const [ NavNotifyEventElement.tag,
+                                NavNotifyExceptionElement.tag ]);
+
+  RenderingScheduler _r;
+
+  Stream<RenderedEvent<NavNotifyElement>> get onRendered => _r.onRendered;
+
+  bool _notifyOnPause;
+  M.NotificationRepository _repository;
+  StreamSubscription _subscription;
+
+  factory NavNotifyElement(M.NotificationRepository repository,
+                           {bool notifyOnPause: true, RenderingQueue queue}) {
+    assert(repository != null);
+    assert(notifyOnPause != null);
+    NavNotifyElement e = document.createElement(tag.name);
+    e._r = new RenderingScheduler(e, queue: queue);
+    e._repository = repository;
+    e._notifyOnPause = notifyOnPause;
+    return e;
+  }
+
+  NavNotifyElement.created() : super.created();
+
+  @override
+  void attached() {
+    super.attached();
+    _r.enable();
+    _subscription = _repository.onChange.listen((_) => _r.dirty());
+  }
+
+  @override
+  void detached() {
+    super.detached(); children = []; _r.disable();
+    _subscription.cancel();
+  }
+
+  void render() {
+    children = [
+      new DivElement()
+        ..children = [
+          new DivElement()
+            ..children = _repository.list().where(_filter).map(_toElement)
+        ]
+    ];
+  }
+
+  bool _filter(M.Notification notification) {
+    if (!_notifyOnPause && notification is M.EventNotification) {
+      return !M.Event.isPauseEvent(notification.event);
+    }
+    return true;
+  }
+
+  HtmlElement _toElement(M.Notification notification) {
+    if (notification is M.EventNotification) {
+      return new NavNotifyEventElement(notification.event, queue: _r.queue)
+          ..onRemove.listen((_) => _repository.delete(notification));
+    } else if (notification is M.ExceptionNotification) {
+      return new NavNotifyExceptionElement(
+              notification.exception, stacktrace: notification.stacktrace,
+              queue: _r.queue)
+          ..onRemove.listen((_) => _repository.delete(notification));
+    } else {
+      assert(false);
+      return new DivElement()..text = 'Invalid Notification Type';
+    }
+  }
+}