/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at
http://mozilla.org/MPL/2.0/. */
#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.
*/
[scriptable, builtinclass, 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,
[optional] 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.
* Must not be used with shutdown topics (will assert
* on the parent process).
*
* @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,
[optional] in wstring someData );
/**
* hasObservers
*
* Checks to see if there are registered listeners for the given topic.
*
* Implemented in "nsObserverService.cpp".
*
* @param aTopic : The notification topic or subject.
* @param aFound : An out parameter; True if there are registered observers,
* False otherwise.
*/
[noscript, notxpcom, nostdcall] boolean hasObservers(in string aTopic);
%{C++
/**
* notifyWhenScriptSafe
*
* Notifies all registered listeners of the given topic once it is safe to
* run script.
*
* Implemented in "nsObserverService.cpp".
*
* @param aSubject : Notification specific interface pointer.
* @param aTopic : The notification topic or subject.
* @param someData : Notification specific wide string.
*/
nsresult NotifyWhenScriptSafe(nsISupports* aSubject,
const char* aTopic,
const char16_t* aData = nullptr);
%}
/**
* enumerateObservers
*
* Returns an enumeration of all registered listeners.
*
* @param aTopic : The notification topic or subject.
*/
nsISimpleEnumerator enumerateObservers( in string aTopic );
};
