gecko-dev/xpcom/ds/nsObserverList.h
Nicholas Nethercote 7cc5e1d84e Bug 1268772 (part 5) - Use MOZ_MUST_USE in other parts of xpcom/ds/. r=erahm.
As well as adding MOZ_MUST_USE to a number of functions, this patch:

- Changes the return type of nsObserverList::GetObserverList() from |nsresult|
  to |void|, because it always returned NS_OK and none of the callers checked
  the result.

- Removes an unnecessary |new| check in nsSupportsArray::Enumerate().

--HG--
extra : rebase_source : 3a93124ef2a7db3929119194ceacbc56bc80d2c6
2016-04-28 17:11:17 +10:00

94 lines
2.5 KiB
C++

/* -*- 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/. */
#ifndef nsObserverList_h___
#define nsObserverList_h___
#include "nsISupports.h"
#include "nsTArray.h"
#include "nsCOMPtr.h"
#include "nsCOMArray.h"
#include "nsIObserver.h"
#include "nsIWeakReference.h"
#include "nsHashKeys.h"
#include "nsISimpleEnumerator.h"
#include "mozilla/Attributes.h"
struct ObserverRef
{
ObserverRef(const ObserverRef& aO) : isWeakRef(aO.isWeakRef), ref(aO.ref) {}
explicit ObserverRef(nsIObserver* aObserver) : isWeakRef(false), ref(aObserver) {}
explicit ObserverRef(nsIWeakReference* aWeak) : isWeakRef(true), ref(aWeak) {}
bool isWeakRef;
nsCOMPtr<nsISupports> ref;
nsIObserver* asObserver()
{
NS_ASSERTION(!isWeakRef, "Isn't a strong ref.");
return static_cast<nsIObserver*>((nsISupports*)ref);
}
nsIWeakReference* asWeak()
{
NS_ASSERTION(isWeakRef, "Isn't a weak ref.");
return static_cast<nsIWeakReference*>((nsISupports*)ref);
}
bool operator==(nsISupports* aRhs) const { return ref == aRhs; }
};
class nsObserverList : public nsCharPtrHashKey
{
friend class nsObserverService;
public:
explicit nsObserverList(const char* aKey) : nsCharPtrHashKey(aKey)
{
MOZ_COUNT_CTOR(nsObserverList);
}
~nsObserverList()
{
MOZ_COUNT_DTOR(nsObserverList);
}
MOZ_MUST_USE nsresult AddObserver(nsIObserver* aObserver, bool aOwnsWeak);
MOZ_MUST_USE nsresult RemoveObserver(nsIObserver* aObserver);
void NotifyObservers(nsISupports* aSubject,
const char* aTopic,
const char16_t* aSomeData);
void GetObserverList(nsISimpleEnumerator** aEnumerator);
// Fill an array with the observers of this category.
// The array is filled in last-added-first order.
void FillObserverArray(nsCOMArray<nsIObserver>& aArray);
// Like FillObserverArray(), but only for strongly held observers.
void AppendStrongObservers(nsCOMArray<nsIObserver>& aArray);
private:
nsTArray<ObserverRef> mObservers;
};
class nsObserverEnumerator final : public nsISimpleEnumerator
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSISIMPLEENUMERATOR
explicit nsObserverEnumerator(nsObserverList* aObserverList);
private:
~nsObserverEnumerator() {}
int32_t mIndex; // Counts up from 0
nsCOMArray<nsIObserver> mObservers;
};
#endif /* nsObserverList_h___ */