| // Copyright (c) 2012 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 PPAPI_HOST_RESOURCE_MESSAGE_HANDLER_H_ |
| #define PPAPI_HOST_RESOURCE_MESSAGE_HANDLER_H_ |
| |
| #include "base/macros.h" |
| #include "ppapi/c/pp_stdint.h" |
| #include "ppapi/host/ppapi_host_export.h" |
| |
| namespace IPC { |
| class Message; |
| } |
| |
| namespace ppapi { |
| namespace host { |
| |
| struct HostMessageContext; |
| struct ReplyMessageContext; |
| |
| // This is the base class of classes that can handle resource messages. It |
| // mainly exists at present to share code for checking replies to resource |
| // messages are valid. |
| class PPAPI_HOST_EXPORT ResourceMessageHandler { |
| public: |
| ResourceMessageHandler(); |
| virtual ~ResourceMessageHandler(); |
| |
| // Called when this handler should handle a particular message. This should |
| // call into the the message handler implemented by subclasses (i.e. |
| // |OnResourceMessageReceived|) and perform any additional work necessary to |
| // handle the message (e.g. checking resource replies are valid). True is |
| // returned if the message is handled and false otherwise. |
| virtual bool HandleMessage(const IPC::Message& msg, |
| HostMessageContext* context) = 0; |
| |
| // Send a resource reply message. |
| virtual void SendReply(const ReplyMessageContext& context, |
| const IPC::Message& msg) = 0; |
| |
| protected: |
| // Runs the message handler and checks that a reply was sent if necessary. |
| void RunMessageHandlerAndReply(const IPC::Message& msg, |
| HostMessageContext* context); |
| |
| // Handles messages associated with a given resource object. If the flags |
| // indicate that a response is required, the return value of this function |
| // will be sent as a resource message "response" along with the message |
| // specified in the reply of the context. |
| // |
| // You can do a response asynchronously by returning PP_OK_COMPLETIONPENDING. |
| // This will cause the reply to be skipped, and the class implementing this |
| // function will take responsibility for issuing the callback. The callback |
| // can be issued inside OnResourceMessageReceived before it returns, or at |
| // a future time. |
| // |
| // If you don't have a particular reply message, you can just ignore |
| // the reply in the message context. However, if you have a reply more than |
| // just the int32_t result code, set the reply to be the message of your |
| // choosing. |
| // |
| // The default implementation just returns PP_ERROR_NOTSUPPORTED. |
| virtual int32_t OnResourceMessageReceived(const IPC::Message& msg, |
| HostMessageContext* context); |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(ResourceMessageHandler); |
| }; |
| |
| } // namespace host |
| } // namespace ppapi |
| |
| #endif // PPAPI_HOST_RESOURCE_MESSAGE_HANDLER_H_ |