Centralized event streams

runtime/observatory/lib/src/elements/nav/isolate_menu.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
-  show IsolateRef, IsolateUpdateEvent;
+  show IsolateRef, EventRepository;
 import 'package:observatory/src/elements/helpers/rendering_scheduler.dart';
 import 'package:observatory/src/elements/helpers/tag.dart';
 import 'package:observatory/src/elements/helpers/uris.dart';
 import 'package:observatory/src/elements/nav/menu.dart';
 import 'package:observatory/src/elements/nav/menu_item.dart';
 
 class NavIsolateMenuElement extends HtmlElement implements Renderable {
   static const tag = const Tag<NavIsolateMenuElement>('nav-isolate-menu',
                      dependencies: const [NavMenuElement.tag,
                                           NavMenuItemElement.tag]);
 
   RenderingScheduler _r;
 
   Stream<RenderedEvent<NavIsolateMenuElement>> get onRendered => _r.onRendered;
 
-  Stream<M.IsolateUpdateEvent> _updates;
+  bool _last;
+  M.IsolateRef _isolate;
+  M.EventRepository _events;
   StreamSubscription _updatesSubscription;
 
-  bool _last;
-  M.IsolateRef _isolate;
   bool get last => _last;
   M.IsolateRef get isolate => _isolate;
+
   set last(bool value) => _last = _r.checkAndReact(_last, value);
 
   factory NavIsolateMenuElement(M.IsolateRef isolate,
-      Stream<M.IsolateUpdateEvent> updates, {bool last: false,
+      M.EventRepository events, {bool last: false,
       RenderingQueue queue}) {
     assert(isolate != null);
+    assert(events != null);
     assert(last != null);
     NavIsolateMenuElement e = document.createElement(tag.name);
     e._r = new RenderingScheduler(e, queue: queue);
     e._isolate = isolate;
     e._last = last;
-    e._updates = updates;
+    e._events = events;
     return e;
   }
 
   NavIsolateMenuElement.created() : super.created() {
     _r = new RenderingScheduler(this);
     createShadowRoot();
   }
 
   @override
   void attached() {
     super.attached();
-    assert(_isolate != null);
-    assert(_updates != null);
+    _updatesSubscription = _events.onIsolateUpdate
+      .where((e) => e.isolate.id == isolate.id)
+      .listen((e) { _isolate = e.isolate; _r.dirty(); });
     _r.enable();
-    _updatesSubscription = _updates
-      .where((M.IsolateUpdateEvent e) => e.isolate.id == isolate.id)
-      .listen((M.IsolateUpdateEvent e) { _isolate = e.isolate; _r.dirty(); });
   }
 
   @override
   void detached() {
     super.detached();
     _r.disable(notify: true);
     shadowRoot.children = [];
     assert(_updatesSubscription != null);
     _updatesSubscription.cancel();
     _updatesSubscription = null;
@@ skipping 24 matching lines @@
               link: Uris.persistentHandles(isolate)),
           new NavMenuItemElement('ports', queue: _r.queue,
               link: Uris.ports(isolate)),
           new NavMenuItemElement('logging', queue: _r.queue,
               link: Uris.logging(isolate)),
           new ContentElement()
         ]
     ];
   }
 }