Centralized event streams

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

Index: runtime/observatory/lib/src/elements/nav/vm_menu_wrapper.dart
diff --git a/runtime/observatory/lib/src/elements/nav/vm_menu_wrapper.dart b/runtime/observatory/lib/src/elements/nav/vm_menu_wrapper.dart
index 9327e191661c4c24c24a4e3ed5d2ac3a42a28cd9..ef8bf3db987ebd345b5a1ee7a6e7f489907b5d10 100644
--- a/runtime/observatory/lib/src/elements/nav/vm_menu_wrapper.dart
+++ b/runtime/observatory/lib/src/elements/nav/vm_menu_wrapper.dart
@@ -3,11 +3,8 @@
 // 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/mocks.dart';
-import 'package:observatory/models.dart' as M;
 import 'package:observatory/service.dart';
 import 'package:observatory/service_common.dart';
 import 'package:observatory/src/elements/helpers/tag.dart';
@@ -22,19 +19,18 @@ class NavVMMenuElementWrapper extends HtmlElement {
 
   static const tag = const Tag<NavVMMenuElementWrapper>('vm-nav-menu');
 
-  StreamSubscription _subscription;
-  StreamController<M.VMUpdateEvent> _updatesController =
-      new StreamController<M.VMUpdateEvent>.broadcast();
-
   bool _last = false;
   VM _vm;
+
   bool get last => _last;
   VM get vm => _vm;
+
   set last(bool value) {
-    _last = value; render();
-  }
+    _last = value;
+    render(); }
   set vm(VM value) {
-    _vm = value; _detached(); _attached();
+    _vm = value;
+    render();
   }
 
   NavVMMenuElementWrapper.created() : super.created() {
@@ -47,43 +43,24 @@ class NavVMMenuElementWrapper extends HtmlElement {
   @override
   void attached() {
     super.attached();
-    _attached();
-  }
-
-  @override
-  void detached() {
-    super.detached();
-    _detached();
-  }
-
-  void _attached() {
-    if (_vm != null) {
-      _subscription = _vm.changes.listen((_) {
-        _updatesController.add(new VMUpdateEventMock(vm: _vm));
-      });
-    }
     render();
   }
 
-  void _detached() {
-    if (_subscription != null) {
-      _subscription.cancel();
-      _subscription = null;
-    }
-  }
-
   void render() {
     shadowRoot.children = [];
-    if (_vm == null || _last == null) return;
+    if (_vm == null || _last == null) {
+      return;
+    }
 
     shadowRoot.children = [
-      new NavVMMenuElement(vm, _updatesController.stream, last: last,
-          target: (vm as CommonWebSocketVM)?.target,
-          queue: ObservatoryApplication.app.queue)
+      new NavVMMenuElement(vm, 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');