xpcom/ds/nsIObserverService.idl

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsISupports.idl"
   7
   8 interface nsIObserver;
   9 interface nsISimpleEnumerator;
  10
  11 /**
  12  * nsIObserverService
  13  *
  14  * Service allows a client listener (nsIObserver) to register and unregister for
  15  * notifications of specific string referenced topic. Service also provides a
  16  * way to notify registered listeners and a way to enumerate registered client
  17  * listeners.
  18  */
  19
  20 [scriptable, uuid(D07F5192-E3D1-11d2-8ACD-00105A1B8860)]
  21 interface nsIObserverService : nsISupports
  22 {
  23
  24     /**
  25      * AddObserver
  26      *
  27      * Registers a given listener for a notifications regarding the specified
  28      * topic.
  29      *
  30      * @param anObserve : The interface pointer which will receive notifications.
  31      * @param aTopic    : The notification topic or subject.
  32      * @param ownsWeak  : If set to false, the nsIObserverService will hold a
  33      *                    strong reference to |anObserver|.  If set to true and
  34      *                    |anObserver| supports the nsIWeakReference interface,
  35      *                    a weak reference will be held.  Otherwise an error will be
  36      *                    returned.
  37      */
  38         void addObserver( in nsIObserver anObserver, in string aTopic, in boolean ownsWeak);
  39
  40     /**
  41      * removeObserver
  42      *
  43      * Unregisters a given listener from notifications regarding the specified
  44      * topic.
  45      *
  46      * @param anObserver : The interface pointer which will stop recieving
  47      *                     notifications.
  48      * @param aTopic     : The notification topic or subject.
  49      */
  50     void removeObserver( in nsIObserver anObserver, in string aTopic );
  51
  52     /**
  53      * notifyObservers
  54      *
  55      * Notifies all registered listeners of the given topic.
  56      *
  57      * @param aSubject : Notification specific interface pointer.
  58      * @param aTopic   : The notification topic or subject.
  59      * @param someData : Notification specific wide string.
  60      */
  61     void notifyObservers( in nsISupports aSubject,
  62                           in string aTopic,
  63                           in wstring someData );
  64
  65     /**
  66      * enumerateObservers
  67      *
  68      * Returns an enumeration of all registered listeners.
  69      *
  70      * @param aTopic   : The notification topic or subject.
  71      */
  72         nsISimpleEnumerator enumerateObservers( in string aTopic );
  73
  74
  75 };
  76
  77