[Presentation API] (alternative) 1-UA: send message between controller and receiver page

content/renderer/presentation/renderer_presentation_connection.cc

+// 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.
+
+#include "content/renderer/presentation/renderer_presentation_connection.h"
+
+#include "base/logging.h"
+#include "third_party/WebKit/public/platform/WebString.h"
+#include "third_party/WebKit/public/platform/modules/presentation/WebPresentationConnection.h"
+
+namespace content {
+
+RendererPresentationConnection::RendererPresentationConnection()
+    : binding_(this) {}
+
+RendererPresentationConnection::~RendererPresentationConnection() = default;
+
+blink::mojom::PresentationConnectionPtr RendererPresentationConnection::Bind() {
+  return binding_.CreateInterfacePtrAndBind();
+}
+
+void RendererPresentationConnection::SendString(
+    const blink::WebString& message) {
+  if (!target_connection_)
+    return;
+
+  blink::mojom::SessionMessagePtr session_message =
+      blink::mojom::SessionMessage::New();
+  session_message->type = blink::mojom::PresentationMessageType::TEXT;
+  session_message->message = message.utf8();
+
+  target_connection_->OnSessionMessageReceived(std::move(session_message));
+}
+
+void RendererPresentationConnection::SendArrayBuffer(const uint8_t* data,
+                                                     size_t length) {
+  if (!target_connection_)
+    return;
+
+  blink::mojom::SessionMessagePtr session_message =
+      blink::mojom::SessionMessage::New();
+  session_message->type = blink::mojom::PresentationMessageType::ARRAY_BUFFER;
+  session_message->data = std::vector<uint8_t>(data, data + length);
+
+  target_connection_->OnSessionMessageReceived(std::move(session_message));
+}
+
+void RendererPresentationConnection::SetConnection(
+    blink::WebPresentationConnection* connection) {
+  connection_ = connection;
+}
+
+void RendererPresentationConnection::SetTargetConnection(
+    blink::mojom::PresentationConnectionPtr connection) {
+  target_connection_ = std::move(connection);
+}
+
+void RendererPresentationConnection::OnSessionMessageReceived(
+    blink::mojom::SessionMessagePtr session_message) {
+  DCHECK(connection_);
+
+  switch (session_message->type) {
+    case blink::mojom::PresentationMessageType::TEXT: {
+      // TODO(mfoltz): Do we need to DCHECK(messages[i]->message)?

[mark a. foltz, 2016/10/10 18:28:52]

I'm not sure this TODO makes sense here; we could DCHECK here, but the browser
should be doing validation before passing to the renderer.  Can you check
PSImpl?

Hopefully all the validations will be automatic when crbug.com/632623 is finally
fixed and we have typemaps for all messages passed between the renderer and the
browser.

[zhaobin, 2016/10/12 02:27:33]

Done.

+      connection_->didReceiveTextMessage(
+          blink::WebString::fromUTF8(session_message->message.value()));
+      break;
+    }
+    case blink::mojom::PresentationMessageType::ARRAY_BUFFER:
+    case blink::mojom::PresentationMessageType::BLOB: {
+      // TODO(mfoltz): Do we need to DCHECK(messages[i]->data)?

[mark a. foltz, 2016/10/10 18:28:52]

See comment above.

[zhaobin, 2016/10/12 02:27:34]

Done.

+      connection_->didReceiveBinaryMessage(&(session_message->data->front()),
+                                           session_message->data->size());
+      break;
+    }
+    default: {
+      NOTREACHED();
+      break;
+    }
+  }
+}
+
+}  // namespace content