Move dispatching and sending of the last extension specific messages out of TabContents and Rende...

chrome/browser/extensions/extension_message_handler.h

+// Copyright (c) 2011 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_HANDLER_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_HANDLER_H_
+#pragma once
+
+#include "content/browser/tab_contents/tab_contents_observer.h"
+#include "ipc/ipc_channel.h"
+
+class ExtensionFunctionDispatcher;
+class Profile;
+struct ExtensionHostMsg_DomMessage_Params;
+
+// Filters and dispatches extension-related IPC messages that arrive from
+// renderer/extension processes.  This object is created for renderers and also
+// ExtensionHost/BackgroundContents.  Contrast this with ExtensionTabHelper,
+// which is only created for TabContents.
+class ExtensionMessageHandler : public IPC::Channel::Listener {
+ public:
+  // |sender| is guaranteed to outlive this object.
+  ExtensionMessageHandler(int child_id,
+                          IPC::Message::Sender* sender,
+                          Profile* profile);
+  virtual ~ExtensionMessageHandler();
+
+  // IPC::Channel::Listener overrides.
+  virtual bool OnMessageReceived(const IPC::Message& message);
+
+  // Returns true iff the message can be dispatched.
+  bool CanDispatchRequest(int child_id,
+                          int routing_id,
+                          const ExtensionHostMsg_DomMessage_Params& params);
+
+  void set_extension_function_dispatcher(ExtensionFunctionDispatcher* e) {
+    extension_function_dispatcher_ = e;
+  }
+
+ private:
+  // Message handlers.
+  void OnPostMessage(int port_id, const std::string& message);
+  void OnRequest(const IPC::Message& message,
+                 const ExtensionHostMsg_DomMessage_Params& params);
+
+  // The child id of the corresponding process.  Can be 0.
+  int child_id_;
+
+  // Guaranteed to outlive this object.
+  IPC::Message::Sender* sender_;
+  ExtensionFunctionDispatcher* extension_function_dispatcher_;
+
+  Profile* profile_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionMessageHandler);
+};
+
+// A TabContentsObserver that forwards IPCs to ExtensionMessageHandler.
+class ExtensionMessageObserver : public TabContentsObserver {
+ public:
+  explicit ExtensionMessageObserver(TabContents* tab_contents);
+  ~ExtensionMessageObserver();
+
+ private:
+  // TabContentsObserver overrides.
+  virtual bool OnMessageReceived(const IPC::Message& message);
+
+  void OnRequest(const IPC::Message& message,
+                 const ExtensionHostMsg_DomMessage_Params& params);
+
+  ExtensionMessageHandler handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionMessageObserver);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_HANDLER_H_