extensions/browser/api/messaging/native_message_host.h

   1 // Copyright 2014 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 EXTENSIONS_BROWSER_API_MESSAGING_NATIVE_MESSAGE_HOST_H_
   6 #define EXTENSIONS_BROWSER_API_MESSAGING_NATIVE_MESSAGE_HOST_H_
   7
   8 #include <string>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/single_thread_task_runner.h"
  12 #include "ui/gfx/native_widget_types.h"
  13
  14 namespace extensions {
  15
  16 // An interface for receiving messages from MessageService (Chrome) using the
  17 // Native Messaging API.  A NativeMessageHost object hosts a native component,
  18 // which can run in the browser-process or in a separate process (See
  19 // NativeMessageProcessHost).
  20 class NativeMessageHost {
  21  public:
  22   static const char kFailedToStartError[];
  23   static const char kInvalidNameError[];
  24   static const char kNativeHostExited[];
  25   static const char kNotFoundError[];
  26   static const char kForbiddenError[];
  27   static const char kHostInputOuputError[];
  28
  29   // Callback interface for receiving messages from the native host.
  30   class Client {
  31    public:
  32     virtual ~Client() {}
  33
  34     // Called on the UI thread.
  35     virtual void PostMessageFromNativeHost(const std::string& message) = 0;
  36     virtual void CloseChannel(const std::string& error_message) = 0;
  37   };
  38
  39   // Creates the NativeMessageHost based on the |native_host_name|.
  40   static scoped_ptr<NativeMessageHost> Create(
  41       gfx::NativeView native_view,
  42       const std::string& source_extension_id,
  43       const std::string& native_host_name,
  44       bool allow_user_level,
  45       std::string* error);
  46
  47   virtual ~NativeMessageHost() {}
  48
  49   // Called when a message is received from MessageService (Chrome).
  50   virtual void OnMessage(const std::string& message) = 0;
  51
  52   // Sets the client to start receiving messages from the native host.
  53   virtual void Start(Client* client) = 0;
  54
  55   // Returns the task runner that the host runs on. The Client should only
  56   // invoke OnMessage() on this task runner.
  57   virtual scoped_refptr<base::SingleThreadTaskRunner> task_runner() const = 0;
  58 };
  59
  60 }  // namespace extensions
  61
  62 #endif  // EXTENSIONS_BROWSER_API_MESSAGING_NATIVE_MESSAGE_HOST_H_