xpcom/ds/nsIObserverService.idl

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either of the GNU General Public License Version 2 or later (the "GPL"),
  26  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  27  * in which case the provisions of the GPL or the LGPL are applicable instead
  28  * of those above. If you wish to allow use of your version of this file only
  29  * under the terms of either the GPL or the LGPL, and not to allow others to
  30  * use your version of this file under the terms of the MPL, indicate your
  31  * decision by deleting the provisions above and replace them with the notice
  32  * and other provisions required by the GPL or the LGPL. If you do not delete
  33  * the provisions above, a recipient may use your version of this file under
  34  * the terms of any one of the MPL, the GPL or the LGPL.
  35  *
  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include "nsISupports.idl"
  39
  40 interface nsIObserver;
  41 interface nsISimpleEnumerator;
  42
  43 /**
  44  * nsIObserverService
  45  *
  46  * Service allows a client listener (nsIObserver) to register and unregister for
  47  * notifications of specific string referenced topic. Service also provides a
  48  * way to notify registered listeners and a way to enumerate registered client
  49  * listeners.
  50  *
  51  * @status FROZEN
  52  */
  53
  54 [scriptable, uuid(D07F5192-E3D1-11d2-8ACD-00105A1B8860)]
  55 interface nsIObserverService : nsISupports
  56 {
  57
  58     /**
  59      * AddObserver
  60      *
  61      * Registers a given listener for a notifications regarding the specified
  62      * topic.
  63      *
  64      * @param anObserve : The interface pointer which will receive notifications.
  65      * @param aTopic    : The notification topic or subject.
  66      * @param ownsWeak  : If set to false, the nsIObserverService will hold a
  67      *                    strong reference to |anObserver|.  If set to true and
  68      *                    |anObserver| supports the nsIWeakReference interface,
  69      *                    a weak reference will be held.  Otherwise an error will be
  70      *                    returned.
  71      */
  72         void addObserver( in nsIObserver anObserver, in string aTopic, in boolean ownsWeak);
  73
  74     /**
  75      * removeObserver
  76      *
  77      * Unregisters a given listener from notifications regarding the specified
  78      * topic.
  79      *
  80      * @param anObserver : The interface pointer which will stop recieving
  81      *                     notifications.
  82      * @param aTopic     : The notification topic or subject.
  83      */
  84     void removeObserver( in nsIObserver anObserver, in string aTopic );
  85
  86     /**
  87      * notifyObservers
  88      *
  89      * Notifies all registered listeners of the given topic.
  90      *
  91      * @param aSubject : Notification specific interface pointer.
  92      * @param aTopic   : The notification topic or subject.
  93      * @param someData : Notification specific wide string.
  94      */
  95     void notifyObservers( in nsISupports aSubject,
  96                           in string aTopic,
  97                           in wstring someData );
  98
  99     /**
 100      * enumerateObservers
 101      *
 102      * Returns an enumeration of all registered listeners.
 103      *
 104      * @param aTopic   : The notification topic or subject.
 105      */
 106         nsISimpleEnumerator enumerateObservers( in string aTopic );
 107
 108
 109 };
 110
 111