[Presentation API] (alternative) 1-UA: send message between controller and receiver page

content/renderer/presentation/presentation_dispatcher.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 "content/renderer/presentation/presentation_dispatcher.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "content/public/common/presentation_constants.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/renderer/presentation/presentation_connection_client.h"
+#include "content/renderer/presentation/presentation_connection_proxy.h"
 #include "services/shell/public/cpp/interface_provider.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationAvailabilityObserver.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationController.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationError.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationReceiver.h"
 #include "third_party/WebKit/public/platform/modules/presentation/presentation.mojom.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
@@ skipping 48 matching lines @@
   }
 }
 
 }  // namespace
 
 namespace content {
 
 PresentationDispatcher::PresentationDispatcher(RenderFrame* render_frame)
     : RenderFrameObserver(render_frame),
       controller_(nullptr),
-      binding_(this) {
-}
+      receiver_(nullptr),
+      binding_(this) {}
 
 PresentationDispatcher::~PresentationDispatcher() {
   // Controller should be destroyed before the dispatcher when frame is
   // destroyed.
   DCHECK(!controller_);
 }
 
 void PresentationDispatcher::setController(
     blink::WebPresentationController* controller) {
   // There shouldn't be any swapping from one non-null controller to another.
@@ skipping 272 matching lines @@
   }
   status->availability_callbacks.Clear();
   UpdateListeningState(status);
 }
 
 void PresentationDispatcher::OnDefaultSessionStarted(
     blink::mojom::PresentationSessionInfoPtr session_info) {
   if (!controller_)
     return;
 
-  if (!session_info.is_null()) {
-    presentation_service_->ListenForSessionMessages(session_info.Clone());
-    controller_->didStartDefaultSession(
-        new PresentationConnectionClient(std::move(session_info)));
+  if (session_info.is_null())
+    return;
+
+  presentation_service_->ListenForSessionMessages(session_info.Clone());
+
+  std::unique_ptr<PresentationConnectionProxy> controller_connection_proxy =
+      nullptr;
+  if (session_info->is_offscreen_presentation) {

[mark a. foltz, 2016/10/21 00:53:03]

Can you factor out the common code to create and set the controller connection
proxy?

[zhaobin, 2016/10/22 02:44:13]

Done.

+    controller_connection_proxy =
+        base::MakeUnique<PresentationConnectionProxy>();
+    // Pass controller_connection_proxy to PSImpl and register
+    // it with OffscreenPresentationManager.
+    presentation_service_->SetPresentationConnection(
+        session_info.Clone(), controller_connection_proxy->Bind());
   }
+  controller_->didStartDefaultSession(new PresentationConnectionClient(
+      std::move(session_info), std::move(controller_connection_proxy)));

[mark a. foltz, 2016/10/21 00:53:03]

Is it legal to std::move(nullptr)?

[zhaobin, 2016/10/22 02:44:13]

It works fine...

 }
 
 void PresentationDispatcher::OnSessionCreated(
     blink::WebPresentationConnectionClientCallbacks* callback,
     blink::mojom::PresentationSessionInfoPtr session_info,
     blink::mojom::PresentationErrorPtr error) {
   DCHECK(callback);
   if (!error.is_null()) {
     DCHECK(session_info.is_null());
     callback->onError(blink::WebPresentationError(
         GetWebPresentationErrorTypeFromMojo(error->error_type),
         blink::WebString::fromUTF8(error->message)));
     return;
   }
 
   DCHECK(!session_info.is_null());
   presentation_service_->ListenForSessionMessages(session_info.Clone());
-  callback->onSuccess(
-      base::MakeUnique<PresentationConnectionClient>(std::move(session_info)));
+
+  std::unique_ptr<PresentationConnectionProxy> controller_connection_proxy =
+      nullptr;
+  if (session_info->is_offscreen_presentation) {
+    controller_connection_proxy =
+        base::MakeUnique<PresentationConnectionProxy>();
+    // Pass controller_connection_proxy to PSImpl and register
+    // it with OffscreenPresentationManager.
+    presentation_service_->SetPresentationConnection(
+        session_info.Clone(), controller_connection_proxy->Bind());
+  }
+  // Bind controller_connection_proxy with PresentationConnection
+  // on controller page.
+  callback->onSuccess(base::MakeUnique<PresentationConnectionClient>(
+      session_info.Clone(), std::move(controller_connection_proxy)));
 }
 
 void PresentationDispatcher::OnReceiverConnectionAvailable(
-    blink::mojom::PresentationSessionInfoPtr session_info) {
-  if (receiver_) {
-    receiver_->onReceiverConnectionAvailable(
-        new PresentationConnectionClient(std::move(session_info)));
-  }
+    blink::mojom::PresentationSessionInfoPtr session_info,
+    blink::mojom::PresentationConnectionPtr controller) {
+  if (!receiver_)
+    return;

[mark a. foltz, 2016/10/21 00:53:03]

This seems like a bug, so DCHECK(). IIUC this must be set by Blink before it can
start the connection handshake.  

[zhaobin, 2016/10/22 02:44:13]

Done.

+
+  std::unique_ptr<PresentationConnectionProxy> receiver_connection_proxy =
+      base::MakeUnique<PresentationConnectionProxy>();
+
+  controller->SetTargetConnection(receiver_connection_proxy->Bind());
+  receiver_connection_proxy->SetTargetConnection(std::move(controller));
+  // Bind receiver_connection_proxy with PresentationConnection
+  // in receiver page.
+  receiver_->onReceiverConnectionAvailable(new PresentationConnectionClient(
+      std::move(session_info), std::move(receiver_connection_proxy)));
 }
 
 void PresentationDispatcher::OnConnectionStateChanged(
     blink::mojom::PresentationSessionInfoPtr connection,
     blink::mojom::PresentationConnectionState state) {
   if (!controller_)
     return;
 
   DCHECK(!connection.is_null());
   controller_->didChangeSessionState(
@@ skipping 126 matching lines @@
 PresentationDispatcher::AvailabilityStatus::AvailabilityStatus(
     const GURL& availability_url)
     : url(availability_url),
       last_known_availability(false),
       listening_state(ListeningState::INACTIVE) {}
 
 PresentationDispatcher::AvailabilityStatus::~AvailabilityStatus() {
 }
 
 }  // namespace content