tenfourfox/xpcom/ds/nsObserverList.cpp

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2017-04-19 07:56:45 +00:00
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "nsObserverList.h"
#include "nsAutoPtr.h"
#include "nsCOMArray.h"
#include "nsISimpleEnumerator.h"
#include "xpcpublic.h"
nsresult
nsObserverList::AddObserver(nsIObserver* anObserver, bool 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)
{
RefPtr<nsObserverEnumerator> e(new nsObserverEnumerator(this));
e.forget(anEnumerator);
return NS_OK;
}
void
nsObserverList::FillObserverArray(nsCOMArray<nsIObserver>& aArray)
{
aArray.SetCapacity(mObservers.Length());
nsTArray<ObserverRef> observers(mObservers);
for (int32_t 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::AppendStrongObservers(nsCOMArray<nsIObserver>& aArray)
{
aArray.SetCapacity(aArray.Length() + mObservers.Length());
for (int32_t i = mObservers.Length() - 1; i >= 0; --i) {
if (!mObservers[i].isWeakRef) {
aArray.AppendObject(mObservers[i].asObserver());
}
}
}
void
nsObserverList::NotifyObservers(nsISupports* aSubject,
const char* aTopic,
const char16_t* someData)
{
nsCOMArray<nsIObserver> observers;
FillObserverArray(observers);
for (int32_t i = 0; i < observers.Count(); ++i) {
observers[i]->Observe(aSubject, aTopic, someData);
}
}
NS_IMPL_ISUPPORTS(nsObserverEnumerator, nsISimpleEnumerator)
nsObserverEnumerator::nsObserverEnumerator(nsObserverList* aObserverList)
: mIndex(0)
{
aObserverList->FillObserverArray(mObservers);
}
NS_IMETHODIMP
nsObserverEnumerator::HasMoreElements(bool* 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;
}