[Presentation API] (5th) (1-UA) integrate controller and receiver side for 1-UA messaging

chrome/browser/media/router/browser_presentation_connection_proxy.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_BROWSER_PRESENTATION_CONNECTION_PROXY_H_
+#define CHROME_BROWSER_MEDIA_ROUTER_BROWSER_PRESENTATION_CONNECTION_PROXY_H_
+
+#include "content/public/browser/presentation_service_delegate.h"
+#include "content/public/browser/presentation_session.h"
+#include "mojo/public/cpp/bindings/binding.h"
+
+namespace media_router {
+
+class MediaRouter;
+class MediaRoute;
+
+using OnMessageCallback = base::Callback<void(bool)>;
+
+// This class represents a browser side PresentationConnection. It connects with
+// PresentationConnection owned by a render frame to enable message exchange.
+// Message received on this class is further routed to media router. State of
+// browser
+// side PresentationConnection is always 'connected'.

[mark a. foltz, 2016/12/02 23:06:48]

Wrap comments @ 80 cols

[zhaobin, 2017/01/13 00:05:49]

Done.

+//
+// |SetTargetConnection| sets |target_connection_| to mojo handle of
+// PresentationConnection object owned a render frame, and transits state of
+// |target_connection_| to 'connected'.
+//
+// Send message from page to media router:
+// PresentationConnection::sendString();
+//     -> PresentationDispatcher::DoSendMessage();
+//         -> PresentationConnectionProxy::SendSessionMessage();
+//             --> (mojo call to browser sid PresentationConnection)

[mark a. foltz, 2016/12/02 23:06:48]

typo in 'sid'

[zhaobin, 2017/01/13 00:05:49]

Done.

+//                 -> BrowserPresentationConnectionProxy::OnMessage();
+//                      -> MediaRouter::SendRouteMessage();
+//
+// Instance of this class is only created for non-offscreen presentations.

[mark a. foltz, 2016/12/02 23:06:48]

We should probably decide on consistent terminology: the spec uses 1-UA and 2-UA
to indicate whether the presentation is rendered locally or remotely, however,
those terms make the most sense in the context of the spec.

Maybe "locally rendered" for offscreen vs. "remotely rendered" for
non-offscreen?

Derek, WDYT?

[zhaobin, 2017/01/13 00:05:49]

Done.

+
+class BrowserPresentationConnectionProxy
+    : public NON_EXPORTED_BASE(blink::mojom::PresentationConnection) {
+ public:
+  BrowserPresentationConnectionProxy(const content::PresentationSessionInfo&,
+                                     MediaRouter* router,
+                                     MediaRoute* route);
+  ~BrowserPresentationConnectionProxy() override;
+
+  blink::mojom::PresentationConnectionPtr Bind();
+
+  // blink::mojom::PresentationConnection implementation
+  void SetTargetConnection(
+      blink::mojom::PresentationConnectionPtr connection) override;
+  void OnMessage(blink::mojom::SessionMessagePtr message,
+                 const OnMessageCallback& callback) override;
+  void DidChangeState(blink::mojom::PresentationConnectionState state) override;
+
+  void OnConnectionMessageCallback(bool sent);
+
+ private:
+  content::PresentationSessionInfo session_info_;
+  MediaRouter* router_;

[mark a. foltz, 2016/12/02 23:06:48]

I'm assuming both of these pointers are unowned.  What controls lifetime of
|this|?

[zhaobin, 2017/01/13 00:05:49]

Done.

PresentationFrame owns BrowserPresentationConnectionProxy object.

+  MediaRoute* route_;
+
+  mojo::Binding<blink::mojom::PresentationConnection> binding_;
+  blink::mojom::PresentationConnectionPtr target_connection_;
+  std::unique_ptr<OnMessageCallback> on_message_callback_;

[mark a. foltz, 2016/12/02 23:06:48]

By default, callbacks are copyable, and I'm not aware of a strong reason to pass
ownership of them.  So I don't think this needs to be a unique_ptr.

https://cs.chromium.org/chromium/src/base/callback_forward.h?rcl=0&l=26

[zhaobin, 2017/01/13 00:05:49]

Done.

+};
+
+}  // namespace media_router
+
+#endif  // CHROME_BROWSER_MEDIA_ROUTER_BROWSER_PRESENTATION_CONNECTION_PROXY_H_