[PresentationAPI] Implementing send() from WebPresentationClient to the PresentationService.

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 "base/logging.h"
 #include "content/common/presentation/presentation_service.mojom.h"
 #include "content/public/common/service_registry.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/renderer/presentation/presentation_session_client.h"
 #include "third_party/WebKit/public/platform/WebString.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/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "url/gurl.h"
 
 namespace {
 
+// Maximum number of bytes allowed in a presentation session message.
+static const size_t kMaxPresentationSessionMessageSize = 64 * 1024; // 64 KB.

[mark a. foltz, 2015/05/07 01:34:30]

This should be declared in one place!
Create presentation_constants.{h,cc} files if need be.

[USE s.singapati at gmail.com, 2015/05/07 14:08:52]

Done.

+
 blink::WebPresentationError::ErrorType GetWebPresentationErrorTypeFromMojo(
     presentation::PresentationErrorType mojoErrorType) {
   switch (mojoErrorType) {
     case presentation::PRESENTATION_ERROR_TYPE_NO_AVAILABLE_SCREENS:
       return blink::WebPresentationError::ErrorTypeNoAvailableScreens;
     case presentation::PRESENTATION_ERROR_TYPE_SESSION_REQUEST_CANCELLED:
       return blink::WebPresentationError::ErrorTypeSessionRequestCancelled;
     case presentation::PRESENTATION_ERROR_TYPE_NO_PRESENTATION_FOUND:
       return blink::WebPresentationError::ErrorTypeNoPresentationFound;
     case presentation::PRESENTATION_ERROR_TYPE_UNKNOWN:
@@ skipping 94 matching lines @@
   // OnSessionCreated() is called. |callback| needs to be alive and also needs
   // to be destroyed so we transfer its ownership to the mojo callback.
   presentation_service_->JoinSession(
       presentationUrl.utf8(),
       presentationId.utf8(),
       base::Bind(&PresentationDispatcher::OnSessionCreated,
           base::Unretained(this),
           base::Owned(callback)));
 }
 
+void PresentationDispatcher::sendString(
+    const blink::WebString& presentationUrl,
+    const blink::WebString& presentationId,
+    const blink::WebString& message) {
+  if (message.utf8().size() > kMaxPresentationSessionMessageSize) {
+    // TODO(crbug.com/459008): Limit the size of individual messages to 64k
+    // for now. Consider throwing DOMException or splitting bigger messages
+    // into smaller chunks later.
+    LOG(WARNING) << "message size exceeded limit!";
+    return;
+  }
+
+  presentation::SessionMessage* session_message =
+      new presentation::SessionMessage();
+  session_message->presentation_url = presentationUrl.utf8();
+  session_message->presentation_id = presentationId.utf8();
+  session_message->type = presentation::PresentationMessageType::
+                          PRESENTATION_MESSAGE_TYPE_TEXT;
+  session_message->message = message.utf8();
+
+  message_request_queue_.push(make_linked_ptr(session_message));
+  // Start processing request if only one in the queue.
+  if (message_request_queue_.size() == 1) {
+    const linked_ptr<presentation::SessionMessage>& request =
+        message_request_queue_.front();
+    DoSendMessage(*request);
+  }
+}
+
+void PresentationDispatcher::sendArrayBuffer(
+    const blink::WebString& presentationUrl,
+    const blink::WebString& presentationId,
+    const uint8* data,
+    size_t length) {
+  DCHECK(data);
+  if (length > kMaxPresentationSessionMessageSize) {
+    // TODO(crbug.com/459008): Same as in sendString().
+    LOG(WARNING) << "data size exceeded limit!";
+    return;
+  }
+
+  const std::vector<uint8> vector(data, data + length);
+  presentation::SessionMessage* session_message =
+      new presentation::SessionMessage();
+  session_message->presentation_url = presentationUrl.utf8();
+  session_message->presentation_id = presentationId.utf8();
+  session_message->type = presentation::PresentationMessageType::
+                          PRESENTATION_MESSAGE_TYPE_ARRAY_BUFFER;
+  session_message->data = mojo::Array<uint8>::From(vector);
+
+  message_request_queue_.push(make_linked_ptr(session_message));
+  // Start processing request if only one in the queue.
+  if (message_request_queue_.size() == 1) {
+    const linked_ptr<presentation::SessionMessage>& request =
+        message_request_queue_.front();
+    DoSendMessage(*request);
+  }
+}
+
+void PresentationDispatcher::DoSendMessage(
+    const presentation::SessionMessage& session_message) {
+  ConnectToPresentationServiceIfNeeded();
+
+  presentation::SessionMessagePtr message_request(
+      presentation::SessionMessage::New());
+  message_request->presentation_url = session_message.presentation_url;
+  message_request->presentation_id = session_message.presentation_id;
+  message_request->type = session_message.type;
+  if (session_message.type == presentation::PresentationMessageType::
+                              PRESENTATION_MESSAGE_TYPE_TEXT) {
+    message_request->message = session_message.message;
+  } else if (session_message.type == presentation::PresentationMessageType::
+                                      PRESENTATION_MESSAGE_TYPE_ARRAY_BUFFER) {
+    message_request->data = mojo::Array<uint8>::From(
+                            session_message.data.storage());
+  }
+
+  presentation_service_->SendMessage(
+      message_request.Pass(),
+      base::Bind(&PresentationDispatcher::HandleSendMessageRequests,
+                 base::Unretained(this)));
+}
+
+void PresentationDispatcher::HandleSendMessageRequests(bool success) {
+  // In normal cases, message_request_queue_ should not be empty at this point
+  // of time, but when DidCommitProvisionalLoad() is invoked before receiving
+  // the callback for previous send mojo call, queue would have been emptied.
+  if (message_request_queue_.empty())
+    return;
+
+  if (!success) {
+    // PresentationServiceImpl is informing that Frame has been detached or
+    // navigated away. Invalidate all pending requests.
+    MessageRequestQueue empty;
+    std::swap(message_request_queue_, empty);
+    return;
+  }
+
+  message_request_queue_.pop();
+  if (!message_request_queue_.empty()) {
+    const linked_ptr<presentation::SessionMessage>& request =
+        message_request_queue_.front();
+    DoSendMessage(*request);
+  }
+}
+
 void PresentationDispatcher::closeSession(
     const blink::WebString& presentationUrl,
     const blink::WebString& presentationId) {
   ConnectToPresentationServiceIfNeeded();
 
   presentation_service_->CloseSession(
       presentationUrl.utf8(),
       presentationId.utf8());
 }
 
 void PresentationDispatcher::DidChangeDefaultPresentation() {
   GURL presentation_url(GetPresentationURLFromFrame(render_frame()));
 
   ConnectToPresentationServiceIfNeeded();
   presentation_service_->SetDefaultPresentationURL(
       presentation_url.spec(), mojo::String());
 }
 
+void PresentationDispatcher::DidCommitProvisionalLoad(
+    bool is_new_navigation,
+    bool is_same_page_navigation) {
+  blink::WebFrame* frame = render_frame()->GetWebFrame();
+  // If not top-level navigation.
+  if (frame->parent() || is_same_page_navigation)
+    return;
+
+  // Remove all pending send message requests.
+  MessageRequestQueue empty;
+  std::swap(message_request_queue_, empty);
+}
+
 void PresentationDispatcher::OnScreenAvailabilityChanged(
     const std::string& presentation_url, bool available) {
   if (!controller_)
     return;
 
   // Reset the callback to get the next event.
   DoUpdateAvailableChangeWatched(presentation_url,
                                  controller_->isAvailableChangeWatched());
 
   controller_->didChangeAvailability(available);
@@ skipping 86 matching lines @@
   presentation_service_->ListenForSessionStateChange(base::Bind(
       &PresentationDispatcher::OnSessionStateChange,
       base::Unretained(this)));
   presentation_service_->ListenForSessionMessages(
       base::Bind(&PresentationDispatcher::OnSessionMessagesReceived,
       base::Unretained(this)));
   */
 }
 
 }  // namespace content