michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsISupports.idl"
michael@0: 
michael@0: interface nsIObserver;
michael@0: interface nsISimpleEnumerator;
michael@0: 
michael@0: /**
michael@0:  * nsIObserverService
michael@0:  * 
michael@0:  * Service allows a client listener (nsIObserver) to register and unregister for 
michael@0:  * notifications of specific string referenced topic. Service also provides a 
michael@0:  * way to notify registered listeners and a way to enumerate registered client 
michael@0:  * listeners.
michael@0:  */
michael@0: 
michael@0: [scriptable, uuid(D07F5192-E3D1-11d2-8ACD-00105A1B8860)]
michael@0: interface nsIObserverService : nsISupports 
michael@0: {
michael@0: 
michael@0:     /**
michael@0:      * AddObserver
michael@0:      *
michael@0:      * Registers a given listener for a notifications regarding the specified
michael@0:      * topic.
michael@0:      *
michael@0:      * @param anObserve : The interface pointer which will receive notifications.
michael@0:      * @param aTopic    : The notification topic or subject.
michael@0:      * @param ownsWeak  : If set to false, the nsIObserverService will hold a 
michael@0:      *                    strong reference to |anObserver|.  If set to true and 
michael@0:      *                    |anObserver| supports the nsIWeakReference interface,
michael@0:      *                    a weak reference will be held.  Otherwise an error will be
michael@0:      *                    returned.
michael@0:      */
michael@0:  	void addObserver( in nsIObserver anObserver, in string aTopic, in boolean ownsWeak);
michael@0: 
michael@0:     /**
michael@0:      * removeObserver
michael@0:      *
michael@0:      * Unregisters a given listener from notifications regarding the specified
michael@0:      * topic.
michael@0:      *
michael@0:      * @param anObserver : The interface pointer which will stop recieving
michael@0:      *                     notifications.
michael@0:      * @param aTopic     : The notification topic or subject.
michael@0:      */
michael@0:     void removeObserver( in nsIObserver anObserver, in string aTopic );
michael@0: 
michael@0:     /**
michael@0:      * notifyObservers
michael@0:      *
michael@0:      * Notifies all registered listeners of the given topic.
michael@0:      *
michael@0:      * @param aSubject : Notification specific interface pointer.
michael@0:      * @param aTopic   : The notification topic or subject.
michael@0:      * @param someData : Notification specific wide string.
michael@0:      */
michael@0:     void notifyObservers( in nsISupports aSubject, 
michael@0:                           in string aTopic, 
michael@0:                           in wstring someData );
michael@0: 
michael@0:     /**
michael@0:      * enumerateObservers
michael@0:      *
michael@0:      * Returns an enumeration of all registered listeners.
michael@0:      *
michael@0:      * @param aTopic   : The notification topic or subject.
michael@0:      */
michael@0: 	nsISimpleEnumerator enumerateObservers( in string aTopic );
michael@0: 
michael@0: 
michael@0: };
michael@0: 
michael@0: