[Presentation API] 1-UA presentation support + presenter APIs.

content/browser/presentation/presentation_service_impl.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/browser/presentation/presentation_service_impl.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 184 matching lines @@
     return;
 
   scoped_ptr<ScreenAvailabilityListenerImpl> listener(
       new ScreenAvailabilityListenerImpl(availability_url, this));
   if (delegate_->AddScreenAvailabilityListener(
       render_process_id_,
       render_frame_id_,
       listener.get())) {
     screen_availability_listeners_.set(availability_url, listener.Pass());
   } else {
-    DVLOG(1) << "AddScreenAvailabilityListener failed. Ignoring request.";
+    DVLOG(1) << "AddScreenAvailabilityListener failed. Returning false.";
+    client_->OnScreenAvailabilityUpdated(url, false);
   }
 }
 
 void PresentationServiceImpl::StopListeningForScreenAvailability(
     const mojo::String& url) {
   DVLOG(2) << "StopListeningForScreenAvailability " << url;
   if (!delegate_)
     return;
 
   const std::string& availability_url = url.get();
   auto listener_it = screen_availability_listeners_.find(availability_url);
   if (listener_it == screen_availability_listeners_.end())
     return;
 
   delegate_->RemoveScreenAvailabilityListener(
       render_process_id_,
       render_frame_id_,
       listener_it->second);
   screen_availability_listeners_.erase(listener_it);
 }
 
 void PresentationServiceImpl::ListenForDefaultSessionStart(
-    const DefaultSessionMojoCallback& callback) {
+    const PresentationSessionMojoCallback& callback) {
   if (!default_session_start_context_.get())
     default_session_start_context_.reset(new DefaultSessionStartContext);
   default_session_start_context_->AddCallback(callback);
 }
 
 void PresentationServiceImpl::StartSession(
     const mojo::String& presentation_url,
     const NewSessionMojoCallback& callback) {
   DVLOG(2) << "StartSession";
   if (!delegate_) {
@@ skipping 211 matching lines @@
   if (!delegate_)
     return;
 
   PresentationSessionInfo session_info(session.To<PresentationSessionInfo>());
   delegate_->ListenForSessionMessages(
       render_process_id_, render_frame_id_, session_info,
       base::Bind(&PresentationServiceImpl::OnSessionMessages,
                  weak_factory_.GetWeakPtr(), session_info));
 }
 
+void PresentationServiceImpl::GetPresentationReceiverSession(
+    const PresentationSessionMojoCallback& callback) {
+  DVLOG(2) << "GetPresentationReceiverSession";
+  DCHECK(receiver_session_callback_.is_null());
+  if (!delegate_) {
+    callback.Run(presentation::PresentationSessionInfoPtr());
+    return;
+  }
+
+  receiver_session_callback_ = callback;

[miu, 2015/10/07 21:51:46]

Can there only be one call to GetPresentationReceiverSession() at a time?

Whether yes or no, I don't think you should store the callback as a member of
this class.  Just add an argument to pass |callback| to
OnGetPresentationReceiverSession() and include it in the base::Bind(...) below.

Exception: Does |callback| need to be run if it is has not been run by the time
PresentationServiceImpl is destroyed (i.e., this implies the receiver never
became available)?

[imcheng, 2015/10/10 04:39:43]

It does need to be run before it is destroyed (see L569), which is why we keep a
reference to it in this class. It's one of the quirks with Mojo.

+  delegate_->GetPresentationReceiverSession(
+      render_process_id_, render_frame_id_,
+      base::Bind(&PresentationServiceImpl::OnGetPresentationReceiverSession,
+                 weak_factory_.GetWeakPtr()));
+}
+
+void PresentationServiceImpl::OnGetPresentationReceiverSession(
+    const content::PresentationSessionInfo* session_info) {
+  if (!receiver_session_callback_.is_null()) {
+    receiver_session_callback_.Run(
+        session_info
+            ? presentation::PresentationSessionInfo::From(*session_info)
+            : presentation::PresentationSessionInfoPtr());
+    receiver_session_callback_.reset();
+  }
+}
+
 void PresentationServiceImpl::OnSessionMessages(
     const PresentationSessionInfo& session,
     const ScopedVector<PresentationSessionMessage>& messages,
     bool pass_ownership) {
   DCHECK(client_);
 
   DVLOG(2) << "OnSessionMessages";
   mojo::Array<presentation::SessionMessagePtr> mojoMessages(messages.size());
   for (size_t i = 0; i < messages.size(); ++i)
     mojoMessages[i] = ToMojoSessionMessage(messages[i], pass_ownership);
@@ skipping 48 matching lines @@
   screen_availability_listeners_.clear();
   session_state_listeners_.clear();
 
   start_session_request_id_ = kInvalidRequestSessionId;
   pending_start_session_cb_.reset();
 
   pending_join_session_cbs_.clear();
 
   default_session_start_context_.reset();
 
-  if (on_session_messages_callback_.get()) {
+  if (on_session_messages_callback_) {
     on_session_messages_callback_->Run(
         mojo::Array<presentation::SessionMessagePtr>());
     on_session_messages_callback_.reset();
   }
 
   if (send_message_callback_) {
     // Run the callback with false, indicating the renderer to stop sending
     // the requests and invalidate all pending requests.
     send_message_callback_->Run(false);
     send_message_callback_.reset();
   }
+
+  if (!receiver_session_callback_.is_null()) {
+    receiver_session_callback_.Run(presentation::PresentationSessionInfoPtr());
+    receiver_session_callback_.reset();
+  }
 }
 
 void PresentationServiceImpl::OnDelegateDestroyed() {
   DVLOG(2) << "PresentationServiceImpl::OnDelegateDestroyed";
   delegate_ = nullptr;
   Reset();
 }
 
 void PresentationServiceImpl::OnDefaultPresentationStarted(
     const PresentationSessionInfo& session) {
@@ skipping 75 matching lines @@
 PresentationServiceImpl::DefaultSessionStartContext
 ::DefaultSessionStartContext() {
 }
 
 PresentationServiceImpl::DefaultSessionStartContext
 ::~DefaultSessionStartContext() {
   Reset();
 }
 
 void PresentationServiceImpl::DefaultSessionStartContext::AddCallback(
-    const DefaultSessionMojoCallback& callback) {
+    const PresentationSessionMojoCallback& callback) {
   if (session_.get()) {
     DCHECK(callbacks_.empty());
     callback.Run(presentation::PresentationSessionInfo::From(*session_));
     session_.reset();
   } else {
-    callbacks_.push_back(new DefaultSessionMojoCallback(callback));
+    callbacks_.push_back(new PresentationSessionMojoCallback(callback));
   }
 }
 
 void PresentationServiceImpl::DefaultSessionStartContext::set_session(
     const PresentationSessionInfo& session) {
   if (callbacks_.empty()) {
     session_.reset(new PresentationSessionInfo(session));
   } else {
     DCHECK(!session_.get());
-    ScopedVector<DefaultSessionMojoCallback> callbacks;
+    ScopedVector<PresentationSessionMojoCallback> callbacks;
     callbacks.swap(callbacks_);
     for (const auto& callback : callbacks)
       callback->Run(presentation::PresentationSessionInfo::From(session));
   }
 }
 
 void PresentationServiceImpl::DefaultSessionStartContext::Reset() {
-  ScopedVector<DefaultSessionMojoCallback> callbacks;
+  ScopedVector<PresentationSessionMojoCallback> callbacks;
   callbacks.swap(callbacks_);
   for (const auto& callback : callbacks)
     callback->Run(presentation::PresentationSessionInfoPtr());
   session_.reset();
 }
 
 }  // namespace content