gecko-dev/xpcom/ds/nsEmptyEnumerator.cpp

109 lines
3.2 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: NPL 1.1/GPL 2.0/LGPL 2.1
*
* 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 the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* L. David Baron <dbaron@fas.harvard.edu>
* Pierre Phaneuf <pp@ludusdesign.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either 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 NPL, 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 NPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
An empty enumerator.
*/
#include "nsEmptyEnumerator.h"
////////////////////////////////////////////////////////////////////////
MOZ_DECL_CTOR_COUNTER(EmptyEnumeratorImpl)
EmptyEnumeratorImpl::EmptyEnumeratorImpl(void)
{
MOZ_COUNT_CTOR(EmptyEnumeratorImpl);
}
/* virtual */ EmptyEnumeratorImpl::~EmptyEnumeratorImpl(void)
{
MOZ_COUNT_DTOR(EmptyEnumeratorImpl);
}
// nsISupports interface
NS_IMETHODIMP_(nsrefcnt) EmptyEnumeratorImpl::AddRef(void)
{
return 2;
}
NS_IMETHODIMP_(nsrefcnt) EmptyEnumeratorImpl::Release(void)
{
return 1;
}
NS_IMPL_QUERY_INTERFACE1(EmptyEnumeratorImpl, nsISimpleEnumerator)
// nsISimpleEnumerator interface
NS_IMETHODIMP EmptyEnumeratorImpl::HasMoreElements(PRBool* aResult)
{
*aResult = PR_FALSE;
return NS_OK;
}
NS_IMETHODIMP EmptyEnumeratorImpl::GetNext(nsISupports** aResult)
{
return NS_ERROR_UNEXPECTED;
}
static EmptyEnumeratorImpl* gEmptyEnumerator = nsnull;
extern "C" NS_COM nsresult
NS_NewEmptyEnumerator(nsISimpleEnumerator** aResult)
{
nsresult rv = NS_OK;
if (!gEmptyEnumerator) {
gEmptyEnumerator = new EmptyEnumeratorImpl();
if (!gEmptyEnumerator)
rv = NS_ERROR_OUT_OF_MEMORY;
}
*aResult = gEmptyEnumerator;
return rv;
}
/* static */ void
EmptyEnumeratorImpl::Shutdown()
{
delete gEmptyEnumerator;
gEmptyEnumerator = nsnull;
}