gecko-dev/xpcom/ds/nsObserverService.cpp

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7.1 KiB
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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* 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 Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Pierre Phaneuf <pp@ludusdesign.com>
*/
#define NS_IMPL_IDS
#include "prlock.h"
#include "nsIFactory.h"
#include "nsIServiceManager.h"
#include "nsRepository.h"
#include "nsIObserverService.h"
#include "nsObserverService.h"
#include "nsIObserverList.h"
#include "nsObserverList.h"
#include "nsHashtable.h"
#include "nsString.h"
static NS_DEFINE_CID(kObserverServiceCID, NS_OBSERVERSERVICE_CID);
////////////////////////////////////////////////////////////////////////////////
static nsObserverService* gObserverService = nsnull; // The one-and-only ObserverService
////////////////////////////////////////////////////////////////////////////////
// nsObserverService Implementation
NS_IMPL_THREADSAFE_ISUPPORTS1(nsObserverService, nsIObserverService)
NS_COM nsresult NS_NewObserverService(nsIObserverService** anObserverService)
{
return nsObserverService::GetObserverService(anObserverService);
}
nsObserverService::nsObserverService()
: mObserverTopicTable(NULL)
{
NS_INIT_REFCNT();
mObserverTopicTable = nsnull;
}
nsObserverService::~nsObserverService(void)
{
if(mObserverTopicTable)
delete mObserverTopicTable;
gObserverService = nsnull;
}
NS_METHOD
nsObserverService::Create(nsISupports* outer, const nsIID& aIID, void* *aInstancePtr)
{
nsresult rv;
nsObserverService* os = new nsObserverService();
if (os == NULL)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(os);
rv = os->QueryInterface(aIID, aInstancePtr);
NS_RELEASE(os);
return rv;
}
nsresult nsObserverService::GetObserverService(nsIObserverService** anObserverService)
{
if (! gObserverService) {
nsObserverService* it = new nsObserverService();
if (! it)
return NS_ERROR_OUT_OF_MEMORY;
gObserverService = it;
}
NS_ADDREF(gObserverService);
*anObserverService = gObserverService;
return NS_OK;
}
static PRBool
ReleaseObserverList(nsHashKey *aKey, void *aData, void* closure)
{
nsIObserverList* observerList = NS_STATIC_CAST(nsIObserverList*, aData);
NS_RELEASE(observerList);
return PR_TRUE;
}
nsresult nsObserverService::GetObserverList(const nsString& aTopic, nsIObserverList** anObserverList)
{
if (anObserverList == NULL)
{
return NS_ERROR_NULL_POINTER;
}
if(mObserverTopicTable == NULL) {
mObserverTopicTable = new nsObjectHashtable(nsnull, nsnull, // should never be cloned
ReleaseObserverList, nsnull,
256, PR_TRUE);
if (mObserverTopicTable == NULL)
return NS_ERROR_OUT_OF_MEMORY;
}
nsStringKey key(aTopic);
nsIObserverList *topicObservers = nsnull;
if (mObserverTopicTable->Exists(&key)) {
topicObservers = (nsIObserverList *) mObserverTopicTable->Get(&key);
if (topicObservers != NULL) {
*anObserverList = topicObservers;
} else {
NS_NewObserverList(&topicObservers);
mObserverTopicTable->Put(&key, topicObservers);
}
} else {
NS_NewObserverList(&topicObservers);
*anObserverList = topicObservers;
mObserverTopicTable->Put(&key, topicObservers);
}
return NS_OK;
}
nsresult nsObserverService::AddObserver(nsIObserver* anObserver, const PRUnichar* aTopic)
{
nsIObserverList* anObserverList;
nsresult rv;
if (anObserver == NULL)
{
return NS_ERROR_NULL_POINTER;
}
if (aTopic == NULL)
{
return NS_ERROR_NULL_POINTER;
}
nsAutoString topic(aTopic);
rv = GetObserverList(topic, &anObserverList);
if (NS_FAILED(rv)) return rv;
if (anObserverList) {
return anObserverList->AddObserver(&anObserver);
}
return NS_ERROR_FAILURE;
}
nsresult nsObserverService::RemoveObserver(nsIObserver* anObserver, const PRUnichar* aTopic)
{
nsIObserverList* anObserverList;
nsresult rv;
if (anObserver == NULL)
{
return NS_ERROR_NULL_POINTER;
}
if (aTopic == NULL)
{
return NS_ERROR_NULL_POINTER;
}
nsAutoString topic(aTopic);
rv = GetObserverList(topic, &anObserverList);
if (NS_FAILED(rv)) return rv;
if (anObserverList) {
return anObserverList->RemoveObserver(&anObserver);
}
return NS_ERROR_FAILURE;
}
nsresult nsObserverService::EnumerateObserverList(const PRUnichar* aTopic, nsIEnumerator** anEnumerator)
{
nsIObserverList* anObserverList;
nsresult rv;
if (anEnumerator == NULL)
{
return NS_ERROR_NULL_POINTER;
}
if (aTopic == NULL)
{
return NS_ERROR_NULL_POINTER;
}
nsAutoString topic(aTopic);
rv = GetObserverList(topic, &anObserverList);
if (NS_FAILED(rv)) return rv;
if (anObserverList) {
return anObserverList->EnumerateObserverList(anEnumerator);
}
return NS_ERROR_FAILURE;
}
// Enumerate observers of aTopic and call Observe on each.
nsresult nsObserverService::Notify( nsISupports *aSubject,
const PRUnichar *aTopic,
const PRUnichar *someData ) {
nsresult rv = NS_OK;
nsIEnumerator *observers;
// Get observer list enumerator.
rv = this->EnumerateObserverList( aTopic, &observers );
if ( NS_SUCCEEDED( rv ) ) {
// Go to start of observer list.
rv = observers->First();
// Continue until error or end of list.
while ( observers->IsDone() != NS_OK && NS_SUCCEEDED(rv) ) {
// Get current item (observer).
nsISupports *base;
rv = observers->CurrentItem( &base );
if ( NS_SUCCEEDED( rv ) ) {
// Convert item to nsIObserver.
nsIObserver *observer;
rv = base->QueryInterface( NS_GET_IID(nsIObserver), (void**)&observer );
if ( NS_SUCCEEDED( rv ) && observer ) {
// Tell the observer what's up.
observer->Observe( aSubject, aTopic, someData );
// Release the observer.
observer->Release();
}
NS_IF_RELEASE(base);
}
// Go on to next observer in list.
rv = observers->Next();
}
// Release the observer list.
observers->Release();
rv = NS_OK;
}
return rv;
}
////////////////////////////////////////////////////////////////////////////////