Centralized event streams

runtime/observatory/lib/src/elements/nav/isolate_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 'dart:async';
 
 import 'package:observatory/app.dart';
 import 'package:observatory/service.dart';
-import 'package:observatory/mocks.dart';
-import 'package:observatory/models.dart' as M;
 import 'package:observatory/src/elements/helpers/tag.dart';
 import 'package:observatory/src/elements/shims/binding.dart';
 import 'package:observatory/src/elements/nav/isolate_menu.dart';
 
 @bindable
 class NavIsolateMenuElementWrapper extends HtmlElement {
   static const binder = const Binder<NavIsolateMenuElementWrapper>(const {
       'last':  #last, 'isolate': #isolate
     });
 
   static const tag =
     const Tag<NavIsolateMenuElementWrapper>('isolate-nav-menu');
 
-  final StreamController<M.IsolateUpdateEvent> _updatesController =
-    new StreamController<M.IsolateUpdateEvent>();
-  Stream<M.IsolateUpdateEvent> _updates;
-  StreamSubscription _subscription;
-
   bool _last = false;
   Isolate _isolate;
+  
   bool get last => _last;
   Isolate get isolate => _isolate;
+
   set last(bool value) {
-    _last = value; render();
+    _last = value;
+    render();
   }
   set isolate(Isolate value) {
-    _isolate = value;  _detached(); _attached();
+    _isolate = value;
+    render();
   }
 
   NavIsolateMenuElementWrapper.created() : super.created() {
-    _updates = _updatesController.stream.asBroadcastStream();
     binder.registerCallback(this);
     _last = _getBoolAttribute('last');
     createShadowRoot();
     render();
   }
 
   @override
   void attached() {
     super.attached();
-    _attached();
-  }
-
-  @override
-  void detached() {
-    super.detached();
-    _detached();
-  }
-
-  void _attached() {
-    if (_isolate != null) {
-      _subscription = _isolate.changes.listen((_) {
-        _updatesController.add(new IsolateUpdateEventMock(isolate: isolate));
-      });
-    }
     render();
   }
 
-  void _detached() {
-    if (_subscription != null) {
-      _subscription.cancel();
-      _subscription = null;
-    }
-  }
-
   void render() {
     shadowRoot.children = [];
-    if (_isolate == null || _last == null) return;
+    if (_isolate == null || _last == null) {
+      return;
+    }
 
     shadowRoot.children = [
-      new NavIsolateMenuElement(isolate, _updates, last: last,
-                                 queue: ObservatoryApplication.app.queue)
+      new NavIsolateMenuElement(_isolate, app.events, last: _last,
+          queue: app.queue)
         ..children = [new ContentElement()]
     ];
   }
 
+  ObservatoryApplication get app => ObservatoryApplication.app;
+
   bool _getBoolAttribute(String name) {
     final String value = getAttribute(name);
     return !(value == null || value == 'false');
   }
 }