[Presentation API] (4th)(1-UA blink side) Add WebPresentationConnection and WebPresentationConnecti…

content/renderer/presentation/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 CONTENT_RENDERER_PRESENTATION_PRESENTATION_CONNECTION_PROXY_H_
+#define CONTENT_RENDERER_PRESENTATION_PRESENTATION_CONNECTION_PROXY_H_
+
+#include "base/callback.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "third_party/WebKit/public/platform/modules/presentation/WebPresentationConnection.h"

[mark a. foltz, 2016/11/16 01:16:39]

Nit: Move to .cc

[zhaobin, 2016/11/23 22:52:29]

Done.

+#include "third_party/WebKit/public/platform/modules/presentation/WebPresentationConnectionProxy.h"
+#include "third_party/WebKit/public/platform/modules/presentation/presentation.mojom.h"
+
+namespace content {
+
+// This class connects PresentationConnection owned by one frame with
+// PresentationConnection owned by a different frame.
+//
+// |SetSourceConnection| sets |source_connection_| to PresentationConnection
+// object owned by current frame.

[mark a. foltz, 2016/11/16 01:16:39]

What defines "current frame"?  Maybe just say "owned by one frame."

[zhaobin, 2016/11/23 22:52:29]

Done.

+// |SetTargetConnection| sets |target_connection_| to mojo handle of
+// PresentationConnection object owned by a different frame.
+//
+// When both |source_connection_| and |target_connection_| are set,
+// we can send message or notify state changes between controller and receiver.
+//
+// To send message from controlling frame to receiver frame:
+// 1. Controlling frame invokes connection.sendMessage();
+// 2. This call is delegated to controller presentation connection proxy's
+//    SendString().
+//      PresentationConnectionProxy::SendString() {
+//         target_connection_->OnConnectionMessageReceived();
+//      }
+// 3. Receiver PresentationConnectionProxy::OnConnectionMessageReceived() is
+//  invoked.
+// 4. connection.onmessage event on receiver frame is fired.
+//
+// Sending message from receiver frame to controlling frame and notifying state
+// changes works the same.

[mark a. foltz, 2016/11/16 01:16:39]

Are state changes handled by this proxy or by a different API?

[zhaobin, 2016/11/23 22:52:29]

Will add state change APIs to Proxy class in future patches.

Proxy will handle 'connected' state change for controller and receiver
Proxy will handle 'terminated' state change for receiver ('terminated' state
change for controller is handled by MRP)
close/reconnect not implemented yet, may be handled by proxy or by PSDImpl

+//
+// Instance of this class is only created for offscreen presentations.
+class PresentationConnectionProxy
+    : public blink::WebPresentationConnectionProxy,
+      public NON_EXPORTED_BASE(blink::mojom::PresentationConnection) {
+ public:
+  PresentationConnectionProxy();
+  ~PresentationConnectionProxy() override;
+
+  blink::mojom::PresentationConnectionPtr Bind();
+
+  // WebPresentationConnectionProxy Implementation
+  void SetSourceConnection(
+      blink::WebPresentationConnection* connection) override;
+  void SendString(const blink::WebString& message) override;
+  void SendArrayBuffer(const uint8_t* data, size_t length) override;
+
+  // blink::mojom::PresentationConnection implementation
+  void SetTargetConnection(
+      blink::mojom::PresentationConnectionPtr connection) override;
+  void OnMessage(blink::mojom::SessionMessagePtr message) override;
+
+ private:
+  mojo::Binding<blink::mojom::PresentationConnection> binding_;
+  blink::mojom::PresentationConnectionPtr target_connection_;
+  blink::WebPresentationConnection* source_connection_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_PRESENTATION_PRESENTATION_CONNECTION_PROXY_H_