chromium/components/media_router/browser/presentation/local_presentation_manager.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_MEDIA_ROUTER_BROWSER_PRESENTATION_LOCAL_PRESENTATION_MANAGER_H_
#define COMPONENTS_MEDIA_ROUTER_BROWSER_PRESENTATION_LOCAL_PRESENTATION_MANAGER_H_

#include <map>
#include <memory>
#include <optional>
#include <string>
#include <unordered_map>

#include "base/gtest_prod_util.h"
#include "base/memory/raw_ptr.h"
#include "base/threading/thread_checker.h"
#include "components/keyed_service/core/keyed_service.h"
#include "components/media_router/common/media_route.h"
#include "content/public/browser/global_routing_id.h"
#include "content/public/browser/presentation_service_delegate.h"
#include "mojo/public/cpp/bindings/pending_receiver.h"
#include "mojo/public/cpp/bindings/pending_remote.h"
#include "third_party/blink/public/mojom/presentation/presentation.mojom.h"

namespace content {
class WebContents;
}

namespace media_router {
// Manages all local presentations started in the associated Profile and
// facilitates communication between the controllers and the receiver of a
// local presentation. A local presentation may be an offscreen presentation for
// Presentation API 1-UA mode, or a presentation to a wired display.
//
// Design doc:
// https://docs.google.com/document/d/1XM3jhMJTQyhEC5PDAAJFNIaKh6UUEihqZDz_ztEe4Co/edit#heading=h.hadpx5oi0gml
//
// Example usage:
//
// Receiver is created to host the local presentation and registers itself
// so that controller frames can connect to it:
//
//   LocalPresentationManager* manager =
//       LocalPresentationManagerFactory::GetOrCreateForBrowserContext(
//           web_contents_->GetBrowserContext());
//   manager->OnLocalPresentationReceiverCreated(presentation_info,
//       base::BindRepeating(
//           &PresentationServiceImpl::OnReceiverConnectionAvailable));
//
// Controlling frame establishes connection with the receiver side, resulting
// in a connection with the two endpoints being the controller
// PresentationConnectionRemote and receiver PresentationConnectionReceiver.
// Note calling this will trigger receiver frame's
// PresentationServiceImpl::OnReceiverConnectionAvailable.
//
//   manager->RegisterLocalPresentationController(
//       presentation_info,
//       std::move(controller_connection_remote),
//       std::move(receiver_connection_receiver));
//
// Invoked on receiver's PresentationServiceImpl when controller connection is
// established.
//
//   |presentation_receiver_remote_|: mojo::Remote<T> for the implementation of
//   the blink::mojom::PresentationService interface in the renderer process.
//   |controller_connection_remote|: mojo::PendingRemote<T> for
//   blink::PresentationConnection object in controlling frame's render process.
//   |receiver_connection_receiver|: mojo::PendingReceiver<T> to be bind to
//   blink::PresentationConnection object in receiver frame's render process.
//   void PresentationServiceImpl::OnReceiverConnectionAvailable(
//       const blink::mojom::PresentationInfo& presentation_info,
//       PresentationConnectionRemote controller_connection_remote,
//       PresentationConnectionReceiver receiver_connection_receiver) {
//     presentation_receiver_remote_->OnReceiverConnectionAvailable(
//         blink::mojom::PresentationInfo::From(presentation_info),
//         std::move(controller_connection_remote),
//         std::move(receiver_connection_receiver));
//   }
//
// Send message from controlling/receiver frame to receiver/controlling frame:
//
//   |target_connection_|: member variable of mojo::PendingRemote<T> for
//                         blink::PresentationConnection type, referring to
//                         remote PresentationConnectionProxy object on
//                         receiver/controlling frame.
//   |message|: Text message to be sent.
//   PresentationConnctionPtr::SendString(
//       const blink::WebString& message) {
//     target_connection_->OnMessage(
//         blink::mojom::PresentationConnectionMessage::NewMessage(
//             message.Utf8()),
//         base::BindOnce(&OnMessageReceived));
//   }
//
// A controller or receiver leaves the local presentation (e.g., due to
// navigation) by unregistering themselves from LocalPresentation object.
//
// When the receiver is no longer associated with a local presentation, it
// shall unregister itself with LocalPresentationManager. Unregistration
// will prevent additional controllers from establishing a connection with the
// receiver:
//
//   In receiver's PSImpl::Reset() {
//     local_presentation_manager->
//         OnLocalPresentationReceiverTerminated(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 LocalPresentationManager : public KeyedService { … };

}  // namespace media_router

#endif  // COMPONENTS_MEDIA_ROUTER_BROWSER_PRESENTATION_LOCAL_PRESENTATION_MANAGER_H_