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/* -*- 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
#include "nsObserverList.h"
#include "mozilla/ResultExtensions.h"
#include "mozilla/Try.h"
#include "nsCOMArray.h"
#include "xpcpublic.h"
nsresult nsObserverList::AddObserver(nsIObserver* anObserver, bool ownsWeak) {
NS_ASSERTION(anObserver, "Null input");
MOZ_TRY(mObservers.AppendWeakElement(anObserver, ownsWeak));
return NS_OK;
}
nsresult nsObserverList::RemoveObserver(nsIObserver* anObserver) {
NS_ASSERTION(anObserver, "Null input");
MOZ_TRY(mObservers.RemoveWeakElement(anObserver));
return NS_OK;
}
void nsObserverList::GetObserverList(nsISimpleEnumerator** anEnumerator) {
RefPtr<nsObserverEnumerator> e(new nsObserverEnumerator(this));
e.forget(anEnumerator);
}
nsCOMArray<nsIObserver> nsObserverList::ReverseCloneObserverArray() {
nsCOMArray<nsIObserver> array;
array.SetCapacity(mObservers.Length());
// XXX This could also use RemoveElementsBy if we lifted the promise to fill
// aArray in reverse order. Although there shouldn't be anyone explicitly
// relying on the order, changing this might cause subtle problems, so we
// better leave it as it is.
for (int32_t i = mObservers.Length() - 1; i >= 0; --i) {
nsCOMPtr<nsIObserver> observer = mObservers[i].GetValue();
if (observer) {
array.AppendElement(observer.forget());
} else {
// the object has gone away, remove the weakref
mObservers.RemoveElementAt(i);
}
}
return array;
}
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].IsWeak()) {
nsCOMPtr<nsIObserver> observer = mObservers[i].GetValue();
aArray.AppendObject(observer);
}
}
}
void nsObserverList::NotifyObservers(nsISupports* aSubject, const char* aTopic,
const char16_t* someData) {
const nsCOMArray<nsIObserver> observers = ReverseCloneObserverArray();
for (int32_t i = 0; i < observers.Count(); ++i) {
observers[i]->Observe(aSubject, aTopic, someData);
}
}
nsObserverEnumerator::nsObserverEnumerator(nsObserverList* aObserverList)
: mIndex(0), mObservers(aObserverList->ReverseCloneObserverArray()) {}
NS_IMETHODIMP
nsObserverEnumerator::HasMoreElements(bool* aResult) {
*aResult = (mIndex < mObservers.Count());
return NS_OK;
}
NS_IMETHODIMP
nsObserverEnumerator::GetNext(nsISupports** aResult) {
if (mIndex == mObservers.Count()) {
return NS_ERROR_FAILURE;
}
NS_ADDREF(*aResult = mObservers[mIndex]);
++mIndex;
return NS_OK;
}