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

third_party/WebKit/Source/modules/presentation/PresentationConnection.cpp

 // Copyright 2014 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 "modules/presentation/PresentationConnection.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMArrayBufferView.h"
 #include "core/dom/Document.h"
@@ skipping 124 matching lines @@
 
   void cancel() { m_loader->cancel(); }
 
   DEFINE_INLINE_TRACE() { visitor->trace(m_PresentationConnection); }
 
  private:
   Member<PresentationConnection> m_PresentationConnection;
   std::unique_ptr<FileReaderLoader> m_loader;
 };
 
-PresentationConnection::PresentationConnection(LocalFrame* frame,
-                                               const String& id,
-                                               const KURL& url)
+PresentationConnection::PresentationConnection(
+    LocalFrame* frame,
+    const String& id,
+    const KURL& url,
+    WebPresentationConnectionProxy* proxy)

[mark a. foltz, 2016/10/10 18:28:52]

For a 2-UA presentation (e.g. a Cast app) why is a proxy needed?  It seems like
the connection will just pass the the data onto the Media Router in PSImpl.  Or
is the proxy to the MR?

[zhaobin, 2016/10/12 02:27:34]

Done.

     : DOMWindowProperty(frame),
       m_id(id),
       m_url(url),
       m_state(WebPresentationConnectionState::Connected),
-      m_binaryType(BinaryTypeBlob) {}
+      m_binaryType(BinaryTypeBlob),
+      m_proxy(proxy) {
+  DCHECK(m_proxy);
+  m_proxy->SetConnection(this);
+}
 
 PresentationConnection::~PresentationConnection() {
   ASSERT(!m_blobLoader);
 }
 
 // static
 PresentationConnection* PresentationConnection::take(
     ScriptPromiseResolver* resolver,
     std::unique_ptr<WebPresentationConnectionClient> client,
     PresentationRequest* request) {
@@ skipping 15 matching lines @@
 }
 
 // static
 PresentationConnection* PresentationConnection::take(
     PresentationController* controller,
     std::unique_ptr<WebPresentationConnectionClient> client,
     PresentationRequest* request) {
   ASSERT(controller);
   ASSERT(request);
 
-  PresentationConnection* connection = new PresentationConnection(
-      controller->frame(), client->getId(), client->getUrl());
+  PresentationConnection* connection =
+      new PresentationConnection(controller->frame(), client->getId(),
+                                 client->getUrl(), client->getOrCreateProxy());
   controller->registerConnection(connection);
   request->dispatchEvent(PresentationConnectionAvailableEvent::create(
       EventTypeNames::connectionavailable, connection));
 
   return connection;
 }
 
 // static
 PresentationConnection* PresentationConnection::take(
     PresentationReceiver* receiver,
     std::unique_ptr<WebPresentationConnectionClient> client) {
   DCHECK(receiver);
   DCHECK(client);
 
-  PresentationConnection* connection = new PresentationConnection(
-      receiver->frame(), client->getId(), client->getUrl());
+  PresentationConnection* connection =
+      new PresentationConnection(receiver->frame(), client->getId(),
+                                 client->getUrl(), client->getOrCreateProxy());
   receiver->registerConnection(connection);
 
   return connection;
 }
 
 const AtomicString& PresentationConnection::interfaceName() const {
   return EventTargetNames::PresentationConnection;
 }
 
 ExecutionContext* PresentationConnection::getExecutionContext() const {
@@ skipping 81 matching lines @@
 
 void PresentationConnection::handleMessageQueue() {
   WebPresentationClient* client = presentationClient(getExecutionContext());
   if (!client)
     return;
 
   while (!m_messages.isEmpty() && !m_blobLoader) {
     Message* message = m_messages.first().get();
     switch (message->type) {
       case MessageTypeText:
+        m_proxy->SendString(message->text);

[imcheng, 2016/10/12 02:22:55]

Same question as mark: looks like we are sending message to both the
WebPresentationClient (non 1-ua) and the WebPresentationConnectionProxy (1-ua).
It might be even better if we are only using m_proxy for 1-ua, but see top level
comment.

         client->sendString(m_url, m_id, message->text);
         m_messages.removeFirst();
         break;
       case MessageTypeArrayBuffer:
+        m_proxy->SendArrayBuffer(
+            static_cast<const uint8_t*>(message->arrayBuffer->data()),
+            message->arrayBuffer->byteLength());
         client->sendArrayBuffer(m_url, m_id, static_cast<const uint8_t*>(
                                                  message->arrayBuffer->data()),
                                 message->arrayBuffer->byteLength());
         m_messages.removeFirst();
         break;
       case MessageTypeBlob:
         ASSERT(!m_blobLoader);
         m_blobLoader = new BlobLoader(message->blobDataHandle, this);
         break;
     }
@@ skipping 16 matching lines @@
     m_binaryType = BinaryTypeBlob;
     return;
   }
   if (binaryType == "arraybuffer") {
     m_binaryType = BinaryTypeArrayBuffer;
     return;
   }
   ASSERT_NOT_REACHED();
 }
 
-void PresentationConnection::didReceiveTextMessage(const String& message) {
+void PresentationConnection::didReceiveTextMessage(const WebString& message) {
   if (m_state != WebPresentationConnectionState::Connected)
     return;
 
   dispatchEvent(MessageEvent::create(message));
 }
 
 void PresentationConnection::didReceiveBinaryMessage(const uint8_t* data,
                                                      size_t length) {
   if (m_state != WebPresentationConnectionState::Connected)
     return;
@@ skipping 100 matching lines @@
 void PresentationConnection::tearDown() {
   // Cancel current Blob loading if any.
   if (m_blobLoader) {
     m_blobLoader->cancel();
     m_blobLoader.clear();
   }
   m_messages.clear();
 }
 
 }  // namespace blink