gecko-dev/xpcom/ds/nsObserverList.h
2012-05-21 12:12:37 +01:00

86 lines
2.4 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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"
struct ObserverRef
{
ObserverRef(const ObserverRef& o) :
isWeakRef(o.isWeakRef), ref(o.ref) { }
ObserverRef(nsIObserver* aObserver) : isWeakRef(false), ref(aObserver) { }
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* b) const { return ref == b; }
};
class nsObserverList : public nsCharPtrHashKey
{
public:
nsObserverList(const char *key) : nsCharPtrHashKey(key)
{ MOZ_COUNT_CTOR(nsObserverList); }
~nsObserverList() { MOZ_COUNT_DTOR(nsObserverList); }
nsresult AddObserver(nsIObserver* anObserver, bool ownsWeak);
nsresult RemoveObserver(nsIObserver* anObserver);
void NotifyObservers(nsISupports *aSubject,
const char *aTopic,
const PRUnichar *someData);
nsresult GetObserverList(nsISimpleEnumerator** anEnumerator);
// Fill an array with the observers of this category.
// The array is filled in last-added-first order.
void FillObserverArray(nsCOMArray<nsIObserver> &aArray);
// Unmark any strongly held observers implemented in JS so the cycle
// collector will not traverse them.
void UnmarkGrayStrongObservers();
private:
nsTArray<ObserverRef> mObservers;
};
class nsObserverEnumerator : public nsISimpleEnumerator
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSISIMPLEENUMERATOR
nsObserverEnumerator(nsObserverList* aObserverList);
private:
~nsObserverEnumerator() { }
PRInt32 mIndex; // Counts up from 0
nsCOMArray<nsIObserver> mObservers;
};
#endif /* nsObserverList_h___ */