gecko-dev/xpcom/ds/nsObserverService.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: NPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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):
* Pierre Phaneuf <pp@ludusdesign.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either 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 NPL, 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 NPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "prlog.h"
#include "prlock.h"
#include "nsIFactory.h"
#include "nsIServiceManager.h"
#include "nsIComponentManager.h"
#include "nsIObserverService.h"
#include "nsObserverService.h"
#include "nsObserverList.h"
#include "nsHashtable.h"
#include "nsIWeakReference.h"
#define NS_WEAK_OBSERVERS
static NS_DEFINE_CID(kObserverServiceCID, NS_OBSERVERSERVICE_CID);
#if defined(PR_LOGGING)
// Log module for nsObserverService logging...
//
// To enable logging (see prlog.h for full details):
//
// set NSPR_LOG_MODULES=ObserverService:5
// set NSPR_LOG_FILE=nspr.log
//
// this enables PR_LOG_DEBUG level information and places all output in
// the file nspr.log
PRLogModuleInfo* observerServiceLog = nsnull;
#endif /* PR_LOGGING */
////////////////////////////////////////////////////////////////////////////////
// nsObserverService Implementation
NS_IMPL_THREADSAFE_ISUPPORTS1(nsObserverService, nsIObserverService)
nsObserverService::nsObserverService()
: mObserverTopicTable(nsnull)
{
NS_INIT_REFCNT();
mObserverTopicTable = nsnull;
}
nsObserverService::~nsObserverService(void)
{
if(mObserverTopicTable)
delete mObserverTopicTable;
}
NS_METHOD
nsObserverService::Create(nsISupports* outer, const nsIID& aIID, void* *aInstancePtr)
{
#if defined(PR_LOGGING)
if (!observerServiceLog)
observerServiceLog = PR_NewLogModule("ObserverService");
#endif
nsresult rv;
nsObserverService* os = new nsObserverService();
if (os == nsnull)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(os);
rv = os->QueryInterface(aIID, aInstancePtr);
NS_RELEASE(os);
return rv;
}
static PRBool PR_CALLBACK
ReleaseObserverList(nsHashKey *aKey, void *aData, void* closure)
{
nsObserverList* observerList = NS_STATIC_CAST(nsObserverList*, aData);
delete(observerList);
return PR_TRUE;
}
nsresult nsObserverService::GetObserverList(const char* aTopic, nsObserverList** anObserverList)
{
if (anObserverList == nsnull)
return NS_ERROR_NULL_POINTER;
if(mObserverTopicTable == nsnull)
{
mObserverTopicTable = new nsObjectHashtable(nsnull,
nsnull, // should never be cloned
ReleaseObserverList,
nsnull,
256,
PR_TRUE);
if (mObserverTopicTable == nsnull)
return NS_ERROR_OUT_OF_MEMORY;
}
nsCStringKey key(aTopic);
nsObserverList *topicObservers;
topicObservers = (nsObserverList *) mObserverTopicTable->Get(&key);
if (topicObservers)
{
*anObserverList = topicObservers;
return NS_OK;
}
topicObservers = new nsObserverList();
if (!topicObservers)
return NS_ERROR_OUT_OF_MEMORY;
*anObserverList = topicObservers;
mObserverTopicTable->Put(&key, topicObservers);
return NS_OK;
}
NS_IMETHODIMP nsObserverService::AddObserver(nsIObserver* anObserver, const char* aTopic, PRBool ownsWeak)
{
nsObserverList* anObserverList;
nsresult rv;
if (anObserver == nsnull || aTopic == nsnull)
return NS_ERROR_NULL_POINTER;
rv = GetObserverList(aTopic, &anObserverList);
if (NS_FAILED(rv)) return rv;
return anObserverList->AddObserver(anObserver, ownsWeak);
}
NS_IMETHODIMP nsObserverService::RemoveObserver(nsIObserver* anObserver, const char* aTopic)
{
nsObserverList* anObserverList;
nsresult rv;
if (anObserver == nsnull || aTopic == nsnull)
return NS_ERROR_NULL_POINTER;
rv = GetObserverList(aTopic, &anObserverList);
if (NS_FAILED(rv)) return rv;
return anObserverList->RemoveObserver(anObserver);
}
NS_IMETHODIMP nsObserverService::EnumerateObservers(const char* aTopic, nsISimpleEnumerator** anEnumerator)
{
nsObserverList* anObserverList;
nsresult rv;
if (anEnumerator == nsnull || aTopic == nsnull)
return NS_ERROR_NULL_POINTER;
rv = GetObserverList(aTopic, &anObserverList);
if (NS_FAILED(rv)) return rv;
return anObserverList->GetObserverList(anEnumerator);
}
// Enumerate observers of aTopic and call Observe on each.
NS_IMETHODIMP nsObserverService::NotifyObservers( nsISupports *aSubject,
const char *aTopic,
const PRUnichar *someData ) {
nsresult rv = NS_OK;
nsCOMPtr<nsISimpleEnumerator> observers;
nsCOMPtr<nsISupports> observerRef;
rv = EnumerateObservers( aTopic, getter_AddRefs(observers) );
if ( NS_FAILED( rv ) )
return rv;
PRBool loop = PR_TRUE;
while( NS_SUCCEEDED(observers->HasMoreElements(&loop)) && loop)
{
observers->GetNext(getter_AddRefs(observerRef));
nsCOMPtr<nsIObserver> observer = do_QueryInterface(observerRef);
if ( observer )
observer->Observe( aSubject, aTopic, someData );
#ifdef NS_WEAK_OBSERVERS
else
{ // check for weak reference.
nsCOMPtr<nsIWeakReference> weakRef = do_QueryInterface(observerRef);
if ( weakRef )
weakRef->QueryReferent(NS_GET_IID(nsIObserver), getter_AddRefs(observer));
if ( observer )
observer->Observe( aSubject, aTopic, someData );
PR_LOG(observerServiceLog, PR_LOG_DEBUG, ("Notification - %s\n", aTopic ? aTopic : "undefined"));
}
#endif
}
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////