/* 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 PPAPI_C_PPB_MESSAGING_H_
#define PPAPI_C_PPB_MESSAGING_H_
#include "ppapi/c/pp_instance.h"
#include "ppapi/c/pp_var.h"
#define PPB_MESSAGING_INTERFACE_0_1 "PPB_Messaging;0.1"
#define PPB_MESSAGING_INTERFACE PPB_MESSAGING_INTERFACE_0_1
/**
* @file
* This file defines the PPB_Messaging interface implemented by the browser
* related to sending messages to DOM elements associated with a specific
* module instance.
*
* @addtogroup Interfaces
* @{
*/
/**
* The PPB_Messaging interface contains a pointer to a function related to
* sending messages to JavaScript message event listeners on the DOM element
* associated with a specific module instance.
*/
struct PPB_Messaging {
/**
* PostMessage is a pointer to a function that asynchronously invokes any
* listeners for message events on the DOM element for the given module
* instance. A call to PostMessage() will not block while the message is
* processed.
*
* @param[in] instance A PP_Instance indentifying one instance of a module.
* @param[in] message A PP_Var containing the data to be sent to JavaScript.
* Message can have an int32_t, double, bool, or string value (objects
* are not supported).
*
* Listeners for message events in JavaScript code will receive an object
* conforming to the HTML 5 MessageEvent interface. Specifically, the value of
* message will be contained as a property called data in the received
* MessageEvent.
*
* This messaging system is similar to the system used for listening for
* messages from Web Workers. Refer to
* http://www.whatwg.org/specs/web-workers/current-work/ for further
* information.
*
* Example:
*
* @code
*
*
*
*
*
*
* @endcode
*
* The module instance then invokes PostMessage() as follows:
*
* @code
*
*
* char hello_world[] = "Hello world!";
* PP_Var hello_var = ppb_var_if->VarFromUtf8(instance,
* hello_world,
* sizeof(hello_world));
* ppb_messaging_if->PostMessage(instance, hello_var);
*
* @endcode
*
* The browser will pop-up an alert saying "Hello world!"
*/
void (*PostMessage)(PP_Instance instance, struct PP_Var message);
};
/**
* @}
*/
#endif /* PPAPI_C_PPB_MESSAGING_H_ */