Centralized event streams

runtime/observatory/lib/src/elements/nav/vm_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 VM, IsolateRef, Target, VMUpdateEvent;
+  show VM, 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 NavVMMenuElement extends HtmlElement implements Renderable {
   static const tag = const Tag<NavVMMenuElement>('nav-vm-menu',
                      dependencies: const [NavMenuElement.tag,
                                           NavMenuItemElement.tag]);
 
   RenderingScheduler _r;
 
   Stream<RenderedEvent<NavVMMenuElement>> get onRendered => _r.onRendered;
 
-  Stream<M.VMUpdateEvent> _updates;
+  bool _last;
+  M.VM _vm;
+  M.EventRepository _events;
   StreamSubscription _updatesSubscription;
 
-  bool _last;
-  M.VM _vm;
-  M.Target _target;
+
   bool get last => _last;
   M.VM get vm => _vm;
-  M.Target get target => _target;
+
   set last(bool value) => _last = _r.checkAndReact(_last, value);
 
-  factory NavVMMenuElement(M.VM vm, Stream<M.VMUpdateEvent> updates,
-      {bool last: false, M.Target target, RenderingQueue queue}) {
+  factory NavVMMenuElement(M.VM vm, M.EventRepository events, {bool last: false,
+    RenderingQueue queue}) {
     assert(vm != null);
-    assert(updates != null);
+    assert(events != null);
     assert(last != null);
     NavVMMenuElement e = document.createElement(tag.name);
     e._r = new RenderingScheduler(e, queue: queue);
     e._vm = vm;
-    e._updates = updates;
+    e._events = events;
     e._last = last;
-    e._target = target;
     return e;
   }
 
   NavVMMenuElement.created() : super.created() { createShadowRoot(); }
 
   @override
   void attached() {
     super.attached();
+    _updatesSubscription = _events.onVMUpdate
+        .listen((e) { _vm = e.vm; _r.dirty(); });
     _r.enable();
-    _updatesSubscription = _updates
-      .listen((M.VMUpdateEvent e) { _vm = e.vm; _r.dirty(); });
   }
 
   @override
   void detached() {
     super.detached();
+    shadowRoot.children = [];
     _r.disable(notify: true);
-    shadowRoot.children = [];
-    assert(_updatesSubscription != null);
     _updatesSubscription.cancel();
-    _updatesSubscription = null;
   }
 
   void render() {
-    final String name = (target == null) ? vm.name
-                                         : '${vm.name}@${target.name}';
-    /// TODO(cbernaschina) use the isolate repository.
     shadowRoot.children = [
-      new NavMenuElement(name, link: Uris.vm(), last: last, queue: _r.queue)
+      new NavMenuElement(vm.displayName, link: Uris.vm(), last: last,
+          queue: _r.queue)
         ..children = (
-          _vm.isolates.map((M.IsolateRef isolate) {
+          _vm.isolates.map((isolate) {
             return new NavMenuItemElement(isolate.name, queue: _r.queue,
                 link: Uris.inspect(isolate));
           }).toList()
           ..add(new ContentElement())
         )
     ];
   }
 }