xpcom/ds/nsIObserverService.idl
author hg@mozilla.com
Thu, 22 Mar 2007 10:30:00 -0700
changeset 1 9b2a99adc05e53cd4010de512f50118594756650
child 47159 84c1694a4ca9af3a0fd5605a7ec0e9b9e7bd0129
permissions -rw-r--r--
Free the (distributed) Lizard! Automatic merge from CVS: Module mozilla: tag HG_REPO_INITIAL_IMPORT at 22 Mar 2007 10:30 PDT,

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"

interface nsIObserver;
interface nsISimpleEnumerator;

/**
 * nsIObserverService
 * 
 * Service allows a client listener (nsIObserver) to register and unregister for 
 * notifications of specific string referenced topic. Service also provides a 
 * way to notify registered listeners and a way to enumerate registered client 
 * listeners.
 * 
 * @status FROZEN
 */

[scriptable, uuid(D07F5192-E3D1-11d2-8ACD-00105A1B8860)]
interface nsIObserverService : nsISupports 
{

    /**
     * AddObserver
     *
     * Registers a given listener for a notifications regarding the specified
     * topic.
     *
     * @param anObserve : The interface pointer which will receive notifications.
     * @param aTopic    : The notification topic or subject.
     * @param ownsWeak  : If set to false, the nsIObserverService will hold a 
     *                    strong reference to |anObserver|.  If set to true and 
     *                    |anObserver| supports the nsIWeakReference interface,
     *                    a weak reference will be held.  Otherwise an error will be
     *                    returned.
     */
 	void addObserver( in nsIObserver anObserver, in string aTopic, in boolean ownsWeak);

    /**
     * removeObserver
     *
     * Unregisters a given listener from notifications regarding the specified
     * topic.
     *
     * @param anObserver : The interface pointer which will stop recieving
     *                     notifications.
     * @param aTopic     : The notification topic or subject.
     */
    void removeObserver( in nsIObserver anObserver, in string aTopic );

    /**
     * notifyObservers
     *
     * Notifies all registered listeners of the given topic.
     *
     * @param aSubject : Notification specific interface pointer.
     * @param aTopic   : The notification topic or subject.
     * @param someData : Notification specific wide string.
     */
    void notifyObservers( in nsISupports aSubject, 
                          in string aTopic, 
                          in wstring someData );

    /**
     * enumerateObservers
     *
     * Returns an enumeration of all registered listeners.
     *
     * @param aTopic   : The notification topic or subject.
     */
	nsISimpleEnumerator enumerateObservers( in string aTopic );


};