chrome/renderer/external_host_bindings.h

   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]);
  16 class 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(WebKit::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   WebKit::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_