gecko/xpcom/ds/nsObserverList.cpp

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/* -*- 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 "nsObserverList.h"
#include "nsAutoPtr.h"
#include "nsCOMArray.h"
#include "nsISimpleEnumerator.h"
nsresult
nsObserverList::AddObserver(nsIObserver* anObserver, PRBool ownsWeak)
{
NS_ASSERTION(anObserver, "Null input");
if (!ownsWeak) {
ObserverRef* o = mObservers.AppendElement(anObserver);
if (!o)
return NS_ERROR_OUT_OF_MEMORY;
return NS_OK;
}
nsCOMPtr<nsIWeakReference> weak = do_GetWeakReference(anObserver);
if (!weak)
return NS_NOINTERFACE;
ObserverRef *o = mObservers.AppendElement(weak);
if (!o)
return NS_ERROR_OUT_OF_MEMORY;
return NS_OK;
}
nsresult
nsObserverList::RemoveObserver(nsIObserver* anObserver)
{
NS_ASSERTION(anObserver, "Null input");
if (mObservers.RemoveElement(static_cast<nsISupports*>(anObserver)))
return NS_OK;
nsCOMPtr<nsIWeakReference> observerRef = do_GetWeakReference(anObserver);
if (!observerRef)
return NS_ERROR_FAILURE;
if (!mObservers.RemoveElement(observerRef))
return NS_ERROR_FAILURE;
return NS_OK;
}
nsresult
nsObserverList::GetObserverList(nsISimpleEnumerator** anEnumerator)
{
nsRefPtr<nsObserverEnumerator> e(new nsObserverEnumerator(this));
if (!e)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*anEnumerator = e);
return NS_OK;
}
void
nsObserverList::FillObserverArray(nsCOMArray<nsIObserver> &aArray)
{
aArray.SetCapacity(mObservers.Length());
nsTArray<ObserverRef> observers(mObservers);
for (PRInt32 i = observers.Length() - 1; i >= 0; --i) {
if (observers[i].isWeakRef) {
nsCOMPtr<nsIObserver> o(do_QueryReferent(observers[i].asWeak()));
if (o) {
aArray.AppendObject(o);
}
else {
// the object has gone away, remove the weakref
mObservers.RemoveElement(observers[i].asWeak());
}
}
else {
aArray.AppendObject(observers[i].asObserver());
}
}
}
void
nsObserverList::NotifyObservers(nsISupports *aSubject,
const char *aTopic,
const PRUnichar *someData)
{
nsCOMArray<nsIObserver> observers;
FillObserverArray(observers);
for (PRInt32 i = 0; i < observers.Count(); ++i) {
observers[i]->Observe(aSubject, aTopic, someData);
}
}
NS_IMPL_ISUPPORTS1(nsObserverEnumerator, nsISimpleEnumerator)
nsObserverEnumerator::nsObserverEnumerator(nsObserverList* aObserverList)
: mIndex(0)
{
aObserverList->FillObserverArray(mObservers);
}
NS_IMETHODIMP
nsObserverEnumerator::HasMoreElements(PRBool *aResult)
{
*aResult = (mIndex < mObservers.Count());
return NS_OK;
}
NS_IMETHODIMP
nsObserverEnumerator::GetNext(nsISupports* *aResult)
{
if (mIndex == mObservers.Count()) {
NS_ERROR("Enumerating after HasMoreElements returned false.");
return NS_ERROR_UNEXPECTED;
}
NS_ADDREF(*aResult = mObservers[mIndex]);
++mIndex;
return NS_OK;
}