gecko-dev/xpcom/ds/nsObserverList.h
2020-11-23 16:12:02 +00:00

68 lines
2.0 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 "nsCOMArray.h"
#include "nsIObserver.h"
#include "nsHashKeys.h"
#include "nsMaybeWeakPtr.h"
#include "nsSimpleEnumerator.h"
#include "mozilla/Attributes.h"
class nsObserverList : public nsCharPtrHashKey {
friend class nsObserverService;
public:
explicit nsObserverList(const char* aKey) : nsCharPtrHashKey(aKey) {
MOZ_COUNT_CTOR(nsObserverList);
}
nsObserverList(nsObserverList&& aOther)
: nsCharPtrHashKey(std::move(aOther)),
mObservers(std::move(aOther.mObservers)) {
MOZ_COUNT_CTOR(nsObserverList);
}
MOZ_COUNTED_DTOR(nsObserverList)
[[nodiscard]] nsresult AddObserver(nsIObserver* aObserver, bool aOwnsWeak);
[[nodiscard]] nsresult RemoveObserver(nsIObserver* aObserver);
void NotifyObservers(nsISupports* aSubject, const char* aTopic,
const char16_t* aSomeData);
void GetObserverList(nsISimpleEnumerator** aEnumerator);
// Clone an array with the observers of this category.
// The array is filled in last-added-first order.
nsCOMArray<nsIObserver> ReverseCloneObserverArray();
// Like FillObserverArray(), but only for strongly held observers.
void AppendStrongObservers(nsCOMArray<nsIObserver>& aArray);
private:
nsMaybeWeakPtrArray<nsIObserver> mObservers;
};
class nsObserverEnumerator final : public nsSimpleEnumerator {
public:
NS_DECL_NSISIMPLEENUMERATOR
explicit nsObserverEnumerator(nsObserverList* aObserverList);
const nsID& DefaultInterface() override { return NS_GET_IID(nsIObserver); }
private:
~nsObserverEnumerator() override = default;
int32_t mIndex; // Counts up from 0
nsCOMArray<nsIObserver> mObservers;
};
#endif /* nsObserverList_h___ */