1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CHROME_RENDERER_EXTERNAL_HOST_BINDINGS_H_
6#define CHROME_RENDERER_EXTERNAL_HOST_BINDINGS_H_
7
8#include "ipc/ipc_sender.h"
9#include "webkit/renderer/cpp_bound_class.h"
10
11// ExternalHostBindings is the class backing the "externalHost" object
12// accessible from Javascript
13//
14// We expose one function, for sending a message to the external host:
15//  postMessage(String message[, String target]);
16class ExternalHostBindings : public webkit_glue::CppBoundClass {
17 public:
18  ExternalHostBindings(IPC::Sender* sender, int routing_id);
19  virtual ~ExternalHostBindings();
20
21  // Invokes the registered onmessage handler.
22  // Returns true on successful invocation.
23  bool ForwardMessageFromExternalHost(const std::string& message,
24                                      const std::string& origin,
25                                      const std::string& target);
26
27  // Overridden to hold onto a pointer back to the web frame.
28  void BindToJavascript(blink::WebFrame* frame, const std::string& classname);
29
30 private:
31  // Creates an uninitialized instance of a MessageEvent object.
32  // This is equivalent to calling window.document.createEvent("MessageEvent")
33  // in javascript.
34  bool CreateMessageEvent(NPObject** message_event);
35
36  // The postMessage() function provided to Javascript.
37  void PostMessage(const webkit_glue::CppArgumentList& args,
38                   webkit_glue::CppVariant* result);
39
40  webkit_glue::CppVariant on_message_handler_;
41  blink::WebFrame* frame_;
42  IPC::Sender* sender_;
43  int routing_id_;
44
45  DISALLOW_COPY_AND_ASSIGN(ExternalHostBindings);
46};
47
48#endif  // CHROME_RENDERER_EXTERNAL_HOST_BINDINGS_H_
49