Add GetCurrentRoutes() to MediaRouter API, ensure dialog has routes at init

chrome/browser/ui/webui/media_router/media_router_ui.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/media_router/media_router_ui.h"
 
 #include <algorithm>
 #include <string>
 #include <unordered_map>
 #include <utility>
@@ skipping 117 matching lines @@
     const RoutesUpdatedCallback& callback)
     : MediaRoutesObserver(router, source_id), callback_(callback) {
   DCHECK(!callback_.is_null());
 }
 
 MediaRouterUI::UIMediaRoutesObserver::~UIMediaRoutesObserver() {}
 
 void MediaRouterUI::UIMediaRoutesObserver::OnRoutesUpdated(
     const std::vector<MediaRoute>& routes,
     const std::vector<MediaRoute::Id>& joinable_route_ids) {
-  std::vector<MediaRoute> routes_for_display;
-  std::vector<MediaRoute::Id> joinable_route_ids_for_display;
-  for (const MediaRoute& route : routes) {
-    if (route.for_display()) {
-#ifndef NDEBUG
-      for (const MediaRoute& existing_route : routes_for_display) {
-        if (existing_route.media_sink_id() == route.media_sink_id()) {
-          DVLOG(2) << "Received another route for display with the same sink"
-                   << " id as an existing route. " << route.media_route_id()
-                   << " has the same sink id as "
-                   << existing_route.media_sink_id() << ".";
-        }
-      }
-#endif
-      if (base::ContainsValue(joinable_route_ids, route.media_route_id())) {
-        joinable_route_ids_for_display.push_back(route.media_route_id());
-      }
-
-      routes_for_display.push_back(route);
-    }
-  }
-
-  callback_.Run(routes_for_display, joinable_route_ids_for_display);
+  callback_.Run(routes, joinable_route_ids);
 }
 
 MediaRouterUI::MediaRouterUI(content::WebUI* web_ui)
     : ConstrainedWebDialogUI(web_ui),
       handler_(new MediaRouterWebUIMessageHandler(this)),
       ui_initialized_(false),
       current_route_request_id_(-1),
       route_request_counter_(0),
       initiator_(nullptr),
       router_(nullptr),
@@ skipping 119 matching lines @@
   // Desktop mirror mode is always available.
   query_result_manager_->SetSourcesForCastMode(
       MediaCastMode::DESKTOP_MIRROR, {MediaSourceForDesktop()}, origin);
   initiator_ = initiator;
   SessionID::id_type tab_id = SessionTabHelper::IdForTab(initiator);
   if (tab_id != -1) {
     MediaSource mirroring_source(MediaSourceForTab(tab_id));
     query_result_manager_->SetSourcesForCastMode(MediaCastMode::TAB_MIRROR,
                                                  {mirroring_source}, origin);
   }
+
+  OnRoutesUpdated(router_->GetCurrentRoutes(), std::vector<MediaRoute::Id>());

[imcheng, 2016/12/01 20:06:53]

Please add a comment about why we are doing this. e.g., to ensure we have the
most recent list of routes to initialize the WebUI.

Note that there might still be some artifacts, namely the Cast/Join button (if
applicable) and sink name may show up later. This is because those depend on
query results that might arrive after the initial view is established. This is
probably fine, but please manually verify that they do show up eventually.

[imcheng, 2016/12/01 20:06:53]

On second thought you might want to call this after |cast_modes_| is initialized
since there are some computation that uses it in OnRoutesUpdated.

[takumif, 2016/12/02 19:23:23]

Done.

[takumif, 2016/12/02 19:23:23]

Done.

   UpdateCastModes();
 }
 
 void MediaRouterUI::InitForTest(
     MediaRouter* router,
     content::WebContents* initiator,
     MediaRouterWebUIMessageHandler* handler,
     std::unique_ptr<CreatePresentationConnectionRequest>
         create_session_request) {
   router_ = router;
@@ skipping 33 matching lines @@
 }
 
 void MediaRouterUI::UpdateCastModes() {
   // Gets updated cast modes from |query_result_manager_| and forwards it to UI.
   cast_modes_ = query_result_manager_->GetSupportedCastModes();
   if (ui_initialized_) {
     handler_->UpdateCastModes(cast_modes_, GetPresentationRequestSourceName());
   }
 }
 
+void MediaRouterUI::UpdateCurrentCastModes() {

[imcheng, 2016/12/01 20:06:53]

This should probably be renamed UpdateRouteToCastModesMapping or something
similar to avoid confusing it with UpdateCastModes. Same with
|current_cast_modes_|.

[takumif, 2016/12/02 19:23:23]

Done.

+  std::unordered_map<MediaSource::Id, MediaCastMode> available_source_map;
+  for (const auto& cast_mode : cast_modes_) {
+    for (const auto& source :
+         query_result_manager_->GetSourcesForCastMode(cast_mode)) {
+      available_source_map.insert(std::make_pair(source.id(), cast_mode));
+    }
+  }
+
+  current_cast_modes_.clear();
+  for (const auto& route : routes_) {
+    auto source_entry = available_source_map.find(route.media_source().id());
+    if (source_entry != available_source_map.end()) {
+      current_cast_modes_.insert(
+          std::make_pair(route.media_route_id(), source_entry->second));
+    }
+  }
+}
+
 void MediaRouterUI::Close() {
   ConstrainedWebDialogDelegate* delegate = GetConstrainedDelegate();
   if (delegate) {
     delegate->GetWebDialogDelegate()->OnDialogClosed(std::string());
     delegate->OnDialogCloseFromWebUI();
   }
 }
 
 void MediaRouterUI::UIInitialized() {
   TRACE_EVENT_NESTABLE_ASYNC_END0("media_router", "UI", initiator_);
@@ skipping 158 matching lines @@
   if (ui_initialized_) handler_->UpdateSinks(sinks_);
 }
 
 void MediaRouterUI::SetIssue(const Issue* issue) {
   if (ui_initialized_) handler_->UpdateIssue(issue);
 }
 
 void MediaRouterUI::OnRoutesUpdated(
     const std::vector<MediaRoute>& routes,
     const std::vector<MediaRoute::Id>& joinable_route_ids) {
-  routes_ = routes;
-  joinable_route_ids_ = joinable_route_ids;
+  routes_.clear();
+  joinable_route_ids_.clear();
 
-  std::unordered_map<MediaSource::Id, MediaCastMode> available_source_map;
-  for (const auto& cast_mode : cast_modes_) {
-    for (const auto& source :
-         query_result_manager_->GetSourcesForCastMode(cast_mode)) {
-      available_source_map.insert(std::make_pair(source.id(), cast_mode));
+  for (const MediaRoute& route : routes) {
+    if (route.for_display()) {
+#ifndef NDEBUG
+      for (const MediaRoute& existing_route : routes_) {
+        if (existing_route.media_sink_id() == route.media_sink_id()) {
+          DVLOG(2) << "Received another route for display with the same sink"
+                   << " id as an existing route. " << route.media_route_id()
+                   << " has the same sink id as "
+                   << existing_route.media_sink_id() << ".";
+        }
+      }
+#endif
+      if (base::ContainsValue(joinable_route_ids, route.media_route_id())) {
+        joinable_route_ids_.push_back(route.media_route_id());
+      }
+
+      routes_.push_back(route);
     }
   }
-
-  current_cast_modes_.clear();
-  for (const auto& route : routes) {
-    auto source_entry = available_source_map.find(route.media_source().id());
-    if (source_entry != available_source_map.end()) {
-      current_cast_modes_.insert(
-          std::make_pair(route.media_route_id(), source_entry->second));
-    }
-  }
+  UpdateCurrentCastModes();
 
   if (ui_initialized_)
     handler_->UpdateRoutes(routes_, joinable_route_ids_, current_cast_modes_);
 }
 
 void MediaRouterUI::OnRouteResponseReceived(
     int route_request_id,
     const MediaSink::Id& sink_id,
     MediaCastMode cast_mode,
     const base::string16& presentation_request_source_name,
@@ skipping 130 matching lines @@
         base::Time::Now() - start_time_);
     start_time_ = base::Time();
   }
 }
 
 void MediaRouterUI::UpdateMaxDialogHeight(int height) {
   handler_->UpdateMaxDialogHeight(height);
 }
 
 }  // namespace media_router