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

chrome/browser/media/router/offscreen_presentation_manager.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 "chrome/browser/media/router/offscreen_presentation_manager.h"
+
+#include <utility>
+
+#include "base/memory/ptr_util.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+#include "url/gurl.h"
+
+namespace media_router {
+
+// OffscreenPresentationManager implementation.
+OffscreenPresentationManager::OffscreenPresentationManager() {
+  thread_checker_.DetachFromThread();

[mark a. foltz, 2016/10/08 00:33:41]

I don't think this is needed. The thread_checker_ constructor binds to the
thread that calls it and that should be the thread checked in this class.

[zhaobin, 2016/10/12 02:27:32]

Done.

+}
+
+OffscreenPresentationManager::~OffscreenPresentationManager() {}

[mark a. foltz, 2016/10/08 00:33:41]

Could there be any still-registered OffscreenPresentation instances here?  If so
don't forget to delete the map values, or (better) store them as unique_ptr<>.

Otherwise, DCHECK() that the map is empty.

[zhaobin, 2016/10/12 02:27:32]

Done.

+
+OffscreenPresentationManager::OffscreenPresentation*
+OffscreenPresentationManager::GetOrCreateOffscreenPresentation(
+    const std::string& presentation_id,
+    const GURL& presentation_url) {
+  auto it = offscreen_presentations_.find(presentation_id);
+  if (it == offscreen_presentations_.end()) {
+    it = offscreen_presentations_
+             .insert(std::make_pair(
+                 presentation_id,
+                 new OffscreenPresentation(presentation_id, presentation_url)))
+             .first;
+  }
+  return it->second;
+}
+
+void OffscreenPresentationManager::RegisterOffscreenPresentationController(
+    const std::string& presentation_id,
+    const GURL& presentation_url,
+    const RenderFrameHostId& render_frame_host_id,
+    content::PresentationConnectionPtr controller) {
+  DVLOG(2) << __FUNCTION__ << " [presentation_id]: " << presentation_id
+           << ", [render_frame_host_id]: " << render_frame_host_id.second;
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto presentation =
+      GetOrCreateOffscreenPresentation(presentation_id, presentation_url);
+  presentation->RegisterController(render_frame_host_id, std::move(controller));
+}
+
+void OffscreenPresentationManager::UnregisterOffscreenPresentationController(
+    const std::string& presentation_id,
+    const RenderFrameHostId& render_frame_host_id) {
+  DVLOG(2) << __FUNCTION__ << " [presentation_id]: " << presentation_id
+           << ", [render_frame_host_id]: " << render_frame_host_id.second;
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto it = offscreen_presentations_.find(presentation_id);
+  if (it == offscreen_presentations_.end())
+    return;
+
+  // Remove presentation if no controller and receiver.
+  it->second->UnregisterController(render_frame_host_id);
+  if (it->second->pending_controllers_.size() == 0 &&
+      it->second->receiver_callback_.is_null())
+    offscreen_presentations_.erase(presentation_id);
+}
+
+void OffscreenPresentationManager::OnOffscreenPresentationReceiverCreated(
+    const std::string& presentation_id,
+    const GURL& presentation_url,
+    const content::ReceiverConnectionAvailableCallback& receiver_callback) {
+  DVLOG(2) << __FUNCTION__ << " [presentation_id]: " << presentation_id;
+  DCHECK(thread_checker_.CalledOnValidThread());
+  auto presentation =
+      GetOrCreateOffscreenPresentation(presentation_id, presentation_url);
+  presentation->RegisterReceiver(receiver_callback);
+}
+
+void OffscreenPresentationManager::OnOffscreenPresentationReceiverTerminated(
+    const std::string& presentation_id) {
+  DVLOG(2) << __FUNCTION__ << " [presentation_id]: " << presentation_id;
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  offscreen_presentations_.erase(presentation_id);
+}
+
+// OffscreenPresentation implementation.
+OffscreenPresentationManager::OffscreenPresentation::OffscreenPresentation(
+    const std::string& presentation_id,
+    const GURL& presentation_url)
+    : presentation_id_(presentation_id),
+      presentation_url_(presentation_url),
+      receiver_callback_(nullptr) {}
+
+OffscreenPresentationManager::OffscreenPresentation::~OffscreenPresentation() {}
+
+void OffscreenPresentationManager::OffscreenPresentation::RegisterController(
+    const RenderFrameHostId& render_frame_host_id,
+    content::PresentationConnectionPtr controller) {
+  if (receiver_callback_) {
+    // Create a receiver PresentationConnectionPtr, and connect it with
+    // controller PresentationConnectionPtr.
+    receiver_callback_.Run(content::PresentationSessionInfo(
+                               presentation_url_.spec(), presentation_id_),
+                           std::move(controller));
+  } else {
+    pending_controllers_.insert(
+        std::make_pair(render_frame_host_id, std::move(controller)));
+  }
+}
+
+void OffscreenPresentationManager::OffscreenPresentation::UnregisterController(
+    const RenderFrameHostId& render_frame_host_id) {
+  pending_controllers_.erase(render_frame_host_id);
+}
+
+void OffscreenPresentationManager::OffscreenPresentation::RegisterReceiver(
+    const content::ReceiverConnectionAvailableCallback& receiver_callback) {
+  DCHECK(!receiver_callback_);
+
+  for (auto& controller : pending_controllers_) {
+    receiver_callback.Run(content::PresentationSessionInfo(
+                              presentation_url_.spec(), presentation_id_),
+                          std::move(controller.second));
+  }
+  receiver_callback_ = receiver_callback;
+  pending_controllers_.clear();
+}
+
+}  // namespace media_router