gecko/xpcom/ds/nsObserverList.h

118 lines
3.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#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___ */