gecko-dev/xpcom/ds/nsObserverList.cpp

137 lines
3.5 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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)
{
nsRefPtr<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::NotifyObservers(nsISupports *aSubject,
const char *aTopic,
const PRUnichar *someData)
{
nsCOMArray<nsIObserver> observers;
FillObserverArray(observers);
for (int32_t i = 0; i < observers.Count(); ++i) {
observers[i]->Observe(aSubject, aTopic, someData);
}
}
void
nsObserverList::UnmarkGrayStrongObservers()
{
for (uint32_t i = 0; i < mObservers.Length(); ++i) {
if (!mObservers[i].isWeakRef) {
xpc_TryUnmarkWrappedGrayObject(mObservers[i].asObserver());
}
}
}
NS_IMPL_ISUPPORTS1(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;
}