[Media Router] Custom Controls 2 - add MediaRouter::GetRouteController()

chrome/browser/media/router/mojo/media_router_mojo_impl.cc

Index: chrome/browser/media/router/mojo/media_router_mojo_impl.cc
diff --git a/chrome/browser/media/router/mojo/media_router_mojo_impl.cc b/chrome/browser/media/router/mojo/media_router_mojo_impl.cc
index ae0ce93801a7f0296b1c1e681699ed6d8169747f..ea2589accf295145a7885fd93b7a2a77c16edf7c 100644
--- a/chrome/browser/media/router/mojo/media_router_mojo_impl.cc
+++ b/chrome/browser/media/router/mojo/media_router_mojo_impl.cc
@@ -21,6 +21,7 @@
 #include "chrome/browser/media/router/media_routes_observer.h"
 #include "chrome/browser/media/router/media_sinks_observer.h"
 #include "chrome/browser/media/router/media_source_helper.h"
+#include "chrome/browser/media/router/mojo/media_route_controller.h"
 #include "chrome/browser/media/router/mojo/media_route_provider_util_win.h"
 #include "chrome/browser/media/router/mojo/media_router_mojo_metrics.h"
 #include "chrome/browser/media/router/route_message.h"
@@ -231,6 +232,7 @@ void MediaRouterMojoImpl::OnRoutesUpdated(
         << "Received routes update without any active observers: "
         << media_source;
   }
+  RemoveInvalidRouteControllers(routes);
 }
 
 void MediaRouterMojoImpl::RouteResponseReceived(
@@ -399,6 +401,28 @@ void MediaRouterMojoImpl::SearchSinks(
                         search_input, domain, sink_callback));
 }
 
+scoped_refptr<MediaRouteController> MediaRouterMojoImpl::GetRouteController(
+    const MediaRoute::Id& route_id) {
+  auto it = route_controllers_.find(route_id);
+  if (it != route_controllers_.end())
+    return scoped_refptr<MediaRouteController>(it->second);
+
+  mojom::MediaControllerPtr media_controller;

[mark a. foltz, 2017/03/30 23:03:28]

Can you prefix Mojo variables with mojo_ for readability?

[takumif, 2017/04/04 03:19:50]

Done.

+  mojom::MediaControllerRequest media_controller_request =
+      mojo::MakeRequest(&media_controller);
+  scoped_refptr<MediaRouteController> route_controller =
+      new MediaRouteController(route_id, std::move(media_controller), this);
+
+  media_route_provider_->CreateMediaRouteController(

[mark a. foltz, 2017/03/30 23:03:28]

What guarantees that the event page is alive?  Most calls through to the MRPM
will queues requests if necessary until the event page is ready to receive them.

[takumif, 2017/04/04 03:19:51]

These requests should be queued as well. I can't std::move arguments into
base::Bind() *, so I'm giving MediaRouteController a method for getting
MediaControllerRequest, and calling that in DoCreateMediaRouteController().

* I tried using base::BindOnce() instead, but was having issues with queuing
requests with std::deque::push_back(). It was calling the copy ctor of
base::OnceCallback rather than the move ctor, even with the use of std::move().

+      route_id, std::move(media_controller_request),
+      base::Bind(&MediaRouterMojoImpl::OnMediaControllerCreated,
+                 base::Unretained(this), route_id));
+  media_route_provider_->SetMediaRouteStatusObserver(
+      route_id, route_controller->BindObserverPtr());
+  route_controllers_.insert({route_id, route_controller.get()});
+  return route_controller;

[mark a. foltz, 2017/03/30 23:03:28]

What state is this in before OnMediaControllerCreated is invoked?

[takumif, 2017/04/04 03:19:50]

Before DoCreateMediaRouteController() is called, route_controller won't be
accepting any media commands, which is fine because the media controls in WebUI
will only be shown after the first media status update. 

+}
+
 bool MediaRouterMojoImpl::RegisterMediaSinksObserver(
     MediaSinksObserver* observer) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
@@ -592,6 +616,14 @@ void MediaRouterMojoImpl::UnregisterRouteMessageObserver(
   }
 }
 
+void MediaRouterMojoImpl::DetachRouteController(
+    const MediaRoute::Id& route_id,
+    MediaRouteController* controller) {
+  auto it = route_controllers_.find(route_id);
+  if (it != route_controllers_.end() && it->second == controller)
+    route_controllers_.erase(it);
+}
+
 void MediaRouterMojoImpl::DoCreateRoute(
     const MediaSource::Id& source_id,
     const MediaSink::Id& sink_id,
@@ -980,4 +1012,34 @@ void MediaRouterMojoImpl::DoUpdateMediaSinks(
   media_route_provider_->UpdateMediaSinks(source_id);
 }
 
+void MediaRouterMojoImpl::RemoveInvalidRouteControllers(
+    const std::vector<MediaRoute>& routes) {
+  auto it = route_controllers_.begin();
+  while (it != route_controllers_.end()) {
+    const MediaRoute::Id& route_id = it->first;
+    if (std::find_if(routes.begin(), routes.end(),
+                     [&route_id](const MediaRoute& route) {
+                       return route.media_route_id() == route_id;
+                     }) == routes.end()) {
+      MediaRouteController* controller = it->second;
+      it = route_controllers_.erase(it);
+      // Invalidate() will result in another erase() call, which will be no-op.
+      controller->Invalidate();

[mark a. foltz, 2017/03/30 23:03:28]

Doesn't this call back into DetachRouteController() above (which will be a no-op
since you just erase()d controller)?

Can you add a specific method like controller->OnRouteInvalid() that will drop
observers without  re-entrancy here?

[takumif, 2017/04/04 03:19:50]

Yes. Added OnRouteInvalid().

+    } else {
+      ++it;
+    }
+  }
+}
+
+void MediaRouterMojoImpl::OnMediaControllerCreated(

[mark a. foltz, 2017/03/30 23:03:28]

Shouldn't this return a boolean per the mojom?

[takumif, 2017/04/04 03:19:51]

No, this is the callback that gets called, so it doesn't need to return
anything.

+    const MediaRoute::Id& route_id,
+    bool success) {
+  if (success)
+    return;
+
+  auto it = route_controllers_.find(route_id);
+  if (it != route_controllers_.end())
+    it->second->Invalidate();
+}
+
 }  // namespace media_router