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

chrome/browser/media/router/offscreen_presentation_manager.h

+// Copyright 2016 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.
+
+#ifndef CHROME_BROWSER_MEDIA_ROUTER_OFFSCREEN_PRESENTATION_MANAGER_H_
+#define CHROME_BROWSER_MEDIA_ROUTER_OFFSCREEN_PRESENTATION_MANAGER_H_
+
+#include <map>
+#include <memory>
+#include <set>

[imcheng, 2016/09/28 07:28:36]

<set> and <vector> not used?

[zhaobin, 2016/09/29 17:20:43]

Done.

+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "chrome/browser/media/router/render_frame_host_id.h"
+#include "components/keyed_service/core/keyed_service.h"
+#include "content/public/browser/presentation_service_delegate.h"
+
+namespace media_router {
+
+class OffscreenPresentation;
+
+// Instances of this class manages all offscreen presentations started in the
+// associated Profile and facilitates communication between the controllers and
+// the
+// receiver of an offscreen presentation.

[imcheng, 2016/09/28 07:28:36]

nit: this can go in previous line.

[zhaobin, 2016/09/29 17:20:43]

Done.

+//
+// Example usage:
+//
+// Receiver is created to host the offscreen presentation and registers itself
+// so that controller frames can connect to it:
+//
+//   OffscreenPresentationManager* manager =
+//       OffscreenPresentationManagerFactory::GetOrCreateForBrowserContext(
+//           context);
+//   manager->RegisterOffscreenPresentationReceiver(presentation_id,
+//       base::Bind(&OnReceiverConnectionAvailable));
+//   ...
+//   void OnReceiverConnectionAvailable(
+//       const content::PresentationSessionInfo& session,
+//       OffscreenPresentationClient* controller) {
+//     [Connects controller PSImpl with receiver PSImpl to send/receive
+//      messages in response to send()]
+//     controller->SetOffscreenPresentationClient(receiver);
+//     receiver->SetOffscreenPresentationClient(controller);
+//   }
+//
+// Controller frame establishes connection with the receiver side, resulting
+// in a session with the two endpoints being the controller frame's PSImpl
+// (OffscreenPresentationClient) and the receiver frame's PSImpl
+// (OffscreenPresentationClient). Note calling this will trigger
+// |OnReceiverConnectionAvailable| on the receiver side.
+//
+//   manager->RegisterOffscreenPresentationController(
+//           presentation_id, controller_frame_id, controller_ptr);
+//
+// To send message from controller to receiver:
+//
+//   In controll's PSImpl::SendSessionMessage() {
+//     receiver.OnSessionMessage();
+//   }
+//
+// A controller or receiver leaves the offscreen presentation (e.g.,
+// due to navigation) by unregistering themselves from
+// OffscreenPresentationConnection object.
+//
+// When the receiver is no longer associated with an offscreen presentation, it
+// shall remove itself from associated controllers and then unregister itself
+// with

[imcheng, 2016/09/28 07:28:36]

nit: line wrap

[zhaobin, 2016/09/29 17:20:43]

Done.

+// OffscreenPresentationManager. Unregistration will prevent additional
+// controllers from establishing a connection with the receiver:
+//
+//   In receiver's PSImpl::Reset() {
+//     for (controller : offscreen_presentation_observers_)
+//       controller->RemoveOffscreenPresentationClient(receiver);
+//   }
+//   manager->UnregisterOffscreenPresentationReceiver(presentation_id);
+//
+// This class is not thread safe. All functions must be invoked on the UI
+// thread. All callbacks passed into this class will also be invoked on UI
+// thread.
+class OffscreenPresentationManager : public KeyedService {
+ public:
+  ~OffscreenPresentationManager() override;
+
+  // Register controller PSImpl to presentation with |presentation_id|,
+  // |render_frame_id|.
+  // Create a new presentation if no presentation with |presentation_id| exists.
+  // |controller| Not owned by this class.
+  void RegisterOffscreenPresentationController(
+      const std::string& presentation_id,
+      int render_frame_id,

[imcheng, 2016/09/28 07:28:36]

Please use RenderFrameHostId here and below for all |render_frame_id|. See:
https://cs.chromium.org/chromium/src/chrome/browser/media/router/presentation...

[zhaobin, 2016/09/29 17:20:43]

Done.

+      content::OffscreenPresentationClient* controller);

[imcheng, 2016/09/28 07:28:36]

Can you forward declare OffscreenPresentationClient?

[zhaobin, 2016/09/29 17:20:43]

changed to content::PresentationConnectionPtr controller in new patch

+
+  // Unregister controller PSImpl to presentation with |presentation_id|,
+  // |render_frame_id|.
+  void UnregisterOffscreenPresentationController(
+      const std::string& presentation_id,
+      int render_frame_id);
+
+  // Register receiver PSImpl to presentation with |presentation_id|.
+  void RegisterOffscreenPresentationReceiver(
+      const std::string& presentation_id,
+      const content::ReceiverConnectionAvailableCallback& receiver_callback);
+
+  void UnregisterOffscreenPresentationReceiver(
+      const std::string& presentation_id);
+
+ private:
+  friend class OffscreenPresentationManagerFactory;
+  friend class OffscreenPresentationManagerTest;
+
+  // Used by OffscreenPresentationManagerFactory::GetOrCreateForBrowserContext.
+  OffscreenPresentationManager();
+
+  // Maps from presentation ID to OffscreenPresentation.
+  std::map<std::string, std::unique_ptr<OffscreenPresentation>>
+      offscreen_presentations_;
+
+  DISALLOW_COPY_AND_ASSIGN(OffscreenPresentationManager);
+};
+
+// Represents an offscreen presentation registered with
+// OffscreenPresentationManager.
+// Contains callback to the receiver to inform it of new sessions
+// established from a controller.
+// Contains set of controllers registered to OffscreenPresentationManager
+// before corresponding receiver.
+class OffscreenPresentation {

[imcheng, 2016/09/28 07:28:36]

It looks like this class is not accessed from outside the .cc and the unit test.
Maybe make this a private nested class of OPM?

[zhaobin, 2016/09/29 17:20:43]

Done.

+ public:
+  explicit OffscreenPresentation(const std::string& presentation_id);
+  ~OffscreenPresentation();
+
+  void RegisterController(int render_frame_id,
+                          content::OffscreenPresentationClient* controller);
+
+  void UnregisterController(int render_frame_id);
+
+  void RegisterReceiver(
+      const content::ReceiverConnectionAvailableCallback& receiver_callback);
+
+ private:
+  friend class OffscreenPresentationManagerTest;
+  friend class OffscreenPresentationManager;
+
+  // URL for current presentation
+  const std::string presentation_url_;
+
+  // presentation_id for current presentation
+  const std::string presentation_id_;
+
+  // proxy to receiver PSImpl
+  content::ReceiverConnectionAvailableCallback receiver_callback_;
+
+  // proxy to controller PSImpl
+  // It only contains controllers registered before receiver_callback_
+  // is set. This map will be cleared in RegisterReceiver().
+  std::map<int, content::OffscreenPresentationClient*> controllers_;

[imcheng, 2016/09/28 07:28:36]

RenderFrameHostId

[imcheng, 2016/09/28 07:28:36]

nit: I'd probably name it pending_controllers_ to be clear.

[zhaobin, 2016/09/29 17:20:43]

Done.

[zhaobin, 2016/09/29 17:20:43]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(OffscreenPresentation);
+};
+
+}  // namespace media_router
+
+#endif  // CHROME_BROWSER_MEDIA_ROUTER_OFFSCREEN_PRESENTATION_MANAGER_H_