ppapi/api/extensions/dev/ppb_ext_events_dev.idl

   1 /* Copyright (c) 2013 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
   6 label Chrome {
   7   M27 = 0.1
   8 };
   9
  10 /**
  11  * Used to represent arbitrary C function pointers. Please note that usually
  12  * the function that a <code>PP_Ext_GenericFuncType</code> pointer points to
  13  * has a different signature than <code>void (*)()</code>.
  14  */
  15 typedef void PP_Ext_GenericFuncType();
  16
  17 /**
  18  * An event listener that can be registered with the browser and receive
  19  * notifications via the callback function.
  20  *
  21  * A function is defined for each event type to return a properly-filled
  22  * <code>PP_Ext_EventListener</code> struct, for example,
  23  * <code>PP_Ext_Alarms_OnAlarm_Dev()</code>.
  24  */
  25 [passByValue]
  26 struct PP_Ext_EventListener {
  27   /**
  28    * The name of the event to register to.
  29    */
  30   cstr_t event_name;
  31   /**
  32    * A callback function whose signature is determined by
  33    * <code>event_name</code>. All calls will happen on the same thread as the
  34    * one on which <code>AddListener()</code> is called.
  35    */
  36   PP_Ext_GenericFuncType func;
  37   /**
  38    * An opaque pointer that will be passed to <code>func</code>.
  39    */
  40   mem_t user_data;
  41 };
  42
  43 interface PPB_Ext_Events_Dev {
  44   /**
  45    * Registers a listener to an event.
  46    *
  47    * @param[in] instance A <code>PP_Instance</code> identifying one instance of
  48    * a module.
  49    * @param[in] listener A <code>PP_Ext_EventListener</code> struct.
  50    *
  51    * @return An listener ID, or 0 if failed.
  52    */
  53   uint32_t AddListener(
  54       [in] PP_Instance instance,
  55       [in] PP_Ext_EventListener listener);
  56
  57   /**
  58    * Deregisters a listener.
  59    *
  60    * @param[in] instance A <code>PP_Instance</code> identifying one instance of
  61    * a module.
  62    * @param[in] listener_id The ID returned by <code>AddListener()</code>.
  63    */
  64   void RemoveListener(
  65       [in] PP_Instance instance,
  66       [in] uint32_t listener_id);
  67 };
  68
  69 #inline c
  70 /**
  71  * Creates a <code>PP_Ext_EventListener</code> struct.
  72  *
  73  * Usually you should not call it directly. Instead you should call those
  74  * functions that return a <code>PP_Ext_EventListener</code> struct for a
  75  * specific event type, for example, <code>PP_Ext_Alarms_OnAlarm_Dev()</code>.
  76  */
  77 PP_INLINE struct PP_Ext_EventListener PP_Ext_MakeEventListener(
  78     const char* event_name,
  79     PP_Ext_GenericFuncType func,
  80     void* user_data) {
  81   struct PP_Ext_EventListener listener;
  82   listener.event_name = event_name;
  83   listener.func = func;
  84   listener.user_data = user_data;
  85   return listener;
  86 }
  87 #endinl