Converted Observatory top-nav-menu element

runtime/observatory/lib/src/elements/nav/top_menu_wrapper.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 'package:observatory/app.dart';
+import 'package:observatory/src/elements/helpers/tag.dart';
+import 'package:observatory/src/elements/shims/binding.dart';
+import 'package:observatory/src/elements/nav/top_menu.dart';
+
+class NavTopMenuElementWrapper extends HtmlElement {
+  static final binder = new Binder<NavTopMenuElementWrapper>(
+    const [const Binding('last')]);
+
+  static const tag = const Tag<NavTopMenuElementWrapper>('top-nav-menu');
+
+  bool _last = false;
+  bool get last => _last;
+  set last(bool value) {
+    _last = value; render();
+  }
+
+  NavTopMenuElementWrapper.created() : super.created() {
+    binder.registerCallback(this);
+    _last = getAttribute('') != null;

[Cutch, 2016/07/20 13:50:45]

what is this checking?

[cbernaschina, 2016/07/20 17:17:00]

It is checking the presence of the attribute.
If it is not set _last is false, if it is set to a non binding value we assign
true. If there is binding this will actually have no effect.

[cbernaschina, 2016/07/20 17:56:12]

Done.

+    createShadowRoot();
+    render();
+  }
+
+  @override
+  void attached() {
+    super.attached();
+    render();
+  }
+
+  void render() {
+    shadowRoot.children = [];
+    if (_last == null) return;
+
+    shadowRoot.children = [
+      new NavTopMenuElement(last: last, queue: ObservatoryApplication.app.queue)
+        ..children = [new ContentElement()]
+    ];
+  }
+}