[Presentation API] (MR side) 1-UA: notify receiver page when receiver connection becomes available

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 "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"
+
+namespace media_router {
+
+// OffscreenPresentationManager implementation. ////////////////////////////////
+OffscreenPresentationManager::OffscreenPresentationManager() {}
+OffscreenPresentationManager::~OffscreenPresentationManager() {}
+
+void OffscreenPresentationManager::RegisterOffscreenPresentationController(
+    const std::string& presentation_id,
+    content::OffscreenPresentationClient* controller) {
+  DVLOG(2)
+      << "OffscreenPresentationManager::RegisterOffscreenPresentationController"
+      << "[id]: " << presentation_id;
+
+  // Create a new presentation.
+  if (!base::ContainsKey(offscreen_presentations_, presentation_id))
+    offscreen_presentations_.insert(std::make_pair(
+        presentation_id,
+        base::WrapUnique(new OffscreenPresentation(presentation_id))));

[imcheng, 2016/09/19 23:01:17]

base::MakeUnique<OffscreenPresentation>(presentation_id)

[zhaobin, 2016/09/23 17:18:18]

Done.

+
+  auto it = offscreen_presentations_.find(presentation_id);

[imcheng, 2016/09/19 23:01:17]

The entry should already exist in offscreen_presentations_ at this point?

I would rewrite this as:

auto it = offscreen_presentations_.find(...);
if (it == offscreen_presentations_.end()) {
  it = offscreen_presentations_.insert(...);
}

it->second->RegisterController(...);

[zhaobin, 2016/09/23 17:18:18]

Done.

+  if (it != offscreen_presentations_.end())
+    it->second->RegisterController(controller);
+}
+
+void OffscreenPresentationManager::UnregisterOffscreenPresentationController(
+    const std::string& presentation_id,
+    content::OffscreenPresentationClient* controller) {
+  DVLOG(2) << "OffscreenPresentationManager::"
+              "UnRegisterOffscreenPresentationController";
+
+  auto it = offscreen_presentations_.find(presentation_id);
+  if (it == offscreen_presentations_.end())
+    return;
+
+  // Remove presentation if no controller.
+  it->second->UnregisterController(controller);
+  if (it->second->controllers_.size() == 0)
+    UnregisterOffscreenPresentationReceiver(presentation_id);
+}
+
+void OffscreenPresentationManager::RegisterOffscreenPresentationReceiver(
+    const std::string& presentation_id,
+    content::OffscreenPresentationClient* receiver) {
+  DVLOG(2)
+      << "OffscreenPresentationManager::RegisterOffscreenPresentationReceiver"
+      << "[id]: " << presentation_id;
+
+  auto it = offscreen_presentations_.find(presentation_id);
+  if (it != offscreen_presentations_.end())
+    it->second->RegisterReceiver(receiver);
+}
+
+void OffscreenPresentationManager::UnregisterOffscreenPresentationReceiver(
+    const std::string& presentation_id) {
+  DVLOG(2) << "OffscreenPresentationManager::"
+              "UnRegisterOffscreenPresentationReceiver";
+
+  auto it = offscreen_presentations_.find(presentation_id);
+  if (it != offscreen_presentations_.end())
+    it->second->UnregisterReceiver();
+
+  offscreen_presentations_.erase(presentation_id);
+}
+
+// OffscreenPresentation implementation. ///////////////////////////////////////
+OffscreenPresentation::OffscreenPresentation(const std::string& presentation_id)
+    : presentation_id_(presentation_id), receiver_(nullptr) {}
+
+OffscreenPresentation::~OffscreenPresentation() {}
+
+void OffscreenPresentation::RegisterController(
+    content::OffscreenPresentationClient* controller) {
+  // Connect controller PSImpl and receiver PSImpl.
+  if (receiver_)
+    AddOffscreenPresentationObserver(controller, receiver_);
+  controllers_.insert(controller);
+}
+
+void OffscreenPresentation::UnregisterController(
+    content::OffscreenPresentationClient* controller) {
+  if (receiver_)
+    RemoveOffscreenPresentationObserver(controller, receiver_);
+  controllers_.erase(controller);
+}
+
+void OffscreenPresentation::RegisterReceiver(
+    content::OffscreenPresentationClient* receiver) {
+  for (const auto& controller : controllers_)
+    AddOffscreenPresentationObserver(controller, receiver);
+  receiver_ = receiver;
+}
+
+void OffscreenPresentation::UnregisterReceiver() {
+  if (!receiver_)
+    return;
+
+  for (const auto& iter : controllers_)
+    RemoveOffscreenPresentationObserver(iter, receiver_);
+  receiver_ = nullptr;
+}
+
+void OffscreenPresentation::AddOffscreenPresentationObserver(
+    content::OffscreenPresentationClient* controller,
+    content::OffscreenPresentationClient* receiver) {
+  // Connect controller PSImpl and receiver PSImpl.
+  controller->AddOffscreenPresentationObserver(receiver);
+  receiver->AddOffscreenPresentationObserver(controller);
+
+  // Build a connection between controller and receiver and
+  // invoke on OnReceiverConnectionAvailable event.
+  receiver->OnReceiverConnectionAvailable(
+      content::PresentationSessionInfo(presentation_url_, presentation_id_));
+}
+
+void OffscreenPresentation::RemoveOffscreenPresentationObserver(
+    content::OffscreenPresentationClient* controller,
+    content::OffscreenPresentationClient* receiver) {
+  // Connect controller PSImpl and receiver PSImpl.
+  controller->RemoveOffscreenPresentationObserver(receiver);
+  receiver->RemoveOffscreenPresentationObserver(controller);
+}
+
+}  // namespace media_router