gecko-dev/xpcom/ds/nsObserverList.cpp

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6.8 KiB
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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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 Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#define NS_WEAK_OBSERVERS
#define NS_IMPL_IDS
#include "pratom.h"
#include "nsIObserverList.h"
#include "nsObserverList.h"
#include "nsString.h"
#include "nsAutoLock.h"
#include "nsCOMPtr.h"
#include "nsIWeakReference.h"
#define NS_AUTOLOCK(__monitor) nsAutoLock __lock(__monitor)
static NS_DEFINE_CID(kObserverListCID, NS_OBSERVERLIST_CID);
class nsObserverListEnumerator : public nsIBidirectionalEnumerator
{
public:
nsObserverListEnumerator( nsISupportsArray* );
virtual ~nsObserverListEnumerator() {};
NS_DECL_ISUPPORTS
NS_DECL_NSIENUMERATOR
NS_DECL_NSIBIDIRECTIONALENUMERATOR
private:
PRUint32 GetTargetArraySize() const;
nsresult MoveToIndex( PRUint32 );
private:
nsCOMPtr<nsISupportsArray> mTargetArray;
PRUint32 mCurrentItemIndex;
};
NS_IMPL_ISUPPORTS2(nsObserverListEnumerator, nsIBidirectionalEnumerator, nsIEnumerator)
nsObserverListEnumerator::nsObserverListEnumerator( nsISupportsArray* anArray )
: mRefCnt(0),
mTargetArray(anArray),
mCurrentItemIndex(0)
{
// nothing else to do here
}
PRUint32
nsObserverListEnumerator::GetTargetArraySize() const
{
PRUint32 array_size = 0;
mTargetArray->Count(&array_size);
return array_size;
}
nsresult
nsObserverListEnumerator::MoveToIndex( PRUint32 aNewIndex )
{
mCurrentItemIndex = aNewIndex;
return (aNewIndex < GetTargetArraySize()) ? NS_OK : NS_ERROR_FAILURE;
}
NS_IMETHODIMP
nsObserverListEnumerator::First()
{
NS_ASSERTION(mTargetArray, "must enumerate over an non-null list");
return MoveToIndex(0);
}
NS_IMETHODIMP
nsObserverListEnumerator::Last()
{
NS_ASSERTION(mTargetArray, "must enumerate over an non-null list");
return MoveToIndex(GetTargetArraySize()-1);
}
NS_IMETHODIMP
nsObserverListEnumerator::Prev()
{
NS_ASSERTION(mTargetArray, "must enumerate over an non-null list");
return MoveToIndex(mCurrentItemIndex-1);
}
NS_IMETHODIMP
nsObserverListEnumerator::Next()
{
NS_ASSERTION(mTargetArray, "must enumerate over an non-null list");
return MoveToIndex(mCurrentItemIndex+1);
}
NS_IMETHODIMP
nsObserverListEnumerator::CurrentItem( nsISupports** aItemPtr )
{
NS_ASSERTION(mTargetArray, "must enumerate over an non-null list");
NS_ASSERTION(aItemPtr, "must supply a place to put the result");
if ( mCurrentItemIndex >= GetTargetArraySize() )
return NS_ERROR_FAILURE;
nsCOMPtr<nsISupports> elementPtr = getter_AddRefs(mTargetArray->ElementAt(mCurrentItemIndex));
if ( !aItemPtr || !elementPtr )
return NS_ERROR_NULL_POINTER;
nsCOMPtr<nsIWeakReference> weakRef = do_QueryInterface(elementPtr);
nsresult status;
if ( weakRef )
status = weakRef->QueryReferent(NS_GET_IID(nsIObserver), NS_REINTERPRET_CAST(void**, aItemPtr));
else
status = elementPtr->QueryInterface(NS_GET_IID(nsIObserver), NS_REINTERPRET_CAST(void**, aItemPtr));
return status;
}
NS_IMETHODIMP
nsObserverListEnumerator::IsDone()
{
NS_ASSERTION(mTargetArray, "must enumerate over an non-null list");
return (mCurrentItemIndex >= GetTargetArraySize()) ? NS_OK : NS_ENUMERATOR_FALSE;
}
////////////////////////////////////////////////////////////////////////////////
// nsObserverList Implementation
NS_IMPL_ISUPPORTS1(nsObserverList, nsIObserverList)
NS_COM nsresult NS_NewObserverList(nsIObserverList** anObserverList)
{
if (anObserverList == NULL)
{
return NS_ERROR_NULL_POINTER;
}
nsObserverList* it = new nsObserverList();
if (it == 0) {
return NS_ERROR_OUT_OF_MEMORY;
}
return it->QueryInterface(NS_GET_IID(nsIObserverList), (void **) anObserverList);
}
nsObserverList::nsObserverList()
: mLock(nsnull),
mObserverList(NULL)
{
NS_INIT_REFCNT();
mLock = PR_NewLock();
}
nsObserverList::~nsObserverList(void)
{
PR_DestroyLock(mLock);
NS_IF_RELEASE(mObserverList);
}
nsresult nsObserverList::AddObserver(nsIObserver** anObserver)
{
nsresult rv;
PRBool inserted;
NS_AUTOLOCK(mLock);
if (anObserver == NULL)
{
return NS_ERROR_NULL_POINTER;
}
if(!mObserverList) {
rv = NS_NewISupportsArray(&mObserverList);
if (NS_FAILED(rv)) return rv;
}
#ifdef NS_WEAK_OBSERVERS
nsCOMPtr<nsISupportsWeakReference> weakRefFactory = do_QueryInterface(*anObserver);
nsCOMPtr<nsISupports> observerRef;
if ( weakRefFactory )
observerRef = getter_AddRefs(NS_STATIC_CAST(nsISupports*, NS_GetWeakReference(weakRefFactory)));
else
observerRef = *anObserver;
if(observerRef) {
inserted = mObserverList->AppendElement(observerRef);
#else
if(*anObserver) {
inserted = mObserverList->AppendElement(*anObserver);
#endif
return inserted ? NS_OK : NS_ERROR_FAILURE;
}
return NS_ERROR_FAILURE;
}
nsresult nsObserverList::RemoveObserver(nsIObserver** anObserver)
{
PRBool removed;
NS_AUTOLOCK(mLock);
if (anObserver == NULL)
{
return NS_ERROR_NULL_POINTER;
}
if(!mObserverList) {
return NS_ERROR_FAILURE;
}
#ifdef NS_WEAK_OBSERVERS
nsCOMPtr<nsISupportsWeakReference> weakRefFactory = do_QueryInterface(*anObserver);
nsCOMPtr<nsISupports> observerRef;
if ( weakRefFactory )
observerRef = getter_AddRefs(NS_STATIC_CAST(nsISupports*, NS_GetWeakReference(weakRefFactory)));
else
observerRef = *anObserver;
if(observerRef) {
removed = mObserverList->RemoveElement(observerRef);
#else
if(*anObserver) {
removed = mObserverList->RemoveElement(*anObserver);
#endif
return removed ? NS_OK : NS_ERROR_FAILURE;
}
return NS_ERROR_FAILURE;
}
NS_IMETHODIMP nsObserverList::EnumerateObserverList(nsIEnumerator** anEnumerator)
{
NS_AUTOLOCK(mLock);
if (anEnumerator == NULL)
{
return NS_ERROR_NULL_POINTER;
}
if(!mObserverList) {
return NS_ERROR_FAILURE;
}
#ifdef NS_WEAK_OBSERVERS
nsCOMPtr<nsIBidirectionalEnumerator> enumerator = new nsObserverListEnumerator(mObserverList);
if ( !enumerator )
return NS_ERROR_OUT_OF_MEMORY;
return CallQueryInterface(enumerator, anEnumerator);
#else
return mObserverList->Enumerate(anEnumerator);
#endif
}