gecko-dev/xpcom/ds/nsObserverList.h

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);
}
nsresult AddObserver(nsIObserver* aObserver, bool aOwnsWeak);
nsresult RemoveObserver(nsIObserver* aObserver);
void NotifyObservers(nsISupports* aSubject,
const char* aTopic,
const char16_t* aSomeData);
nsresult 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___ */