gecko-dev/xpcom/ds/nsEnumeratorUtils.cpp
1999-06-25 01:38:33 +00:00

229 lines
5.3 KiB
C++

/* -*- 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 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#include "nsEnumeratorUtils.h"
nsArrayEnumerator::nsArrayEnumerator(nsISupportsArray* aValueArray)
: mValueArray(aValueArray),
mIndex(0)
{
NS_INIT_REFCNT();
NS_IF_ADDREF(mValueArray);
}
nsArrayEnumerator::~nsArrayEnumerator(void)
{
NS_IF_RELEASE(mValueArray);
}
NS_IMPL_ISUPPORTS(nsArrayEnumerator, nsISimpleEnumerator::GetIID());
NS_IMETHODIMP
nsArrayEnumerator::HasMoreElements(PRBool* aResult)
{
NS_PRECONDITION(aResult != 0, "null ptr");
if (! aResult)
return NS_ERROR_NULL_POINTER;
PRUint32 cnt;
nsresult rv = mValueArray->Count(&cnt);
if (NS_FAILED(rv)) return rv;
*aResult = (mIndex < (PRInt32) cnt);
return NS_OK;
}
NS_IMETHODIMP
nsArrayEnumerator::GetNext(nsISupports** aResult)
{
NS_PRECONDITION(aResult != 0, "null ptr");
if (! aResult)
return NS_ERROR_NULL_POINTER;
PRUint32 cnt;
nsresult rv = mValueArray->Count(&cnt);
if (NS_FAILED(rv)) return rv;
if (mIndex >= (PRInt32) cnt)
return NS_ERROR_UNEXPECTED;
*aResult = mValueArray->ElementAt(mIndex++);
return NS_OK;
}
extern "C" NS_COM nsresult
NS_NewArrayEnumerator(nsISimpleEnumerator* *result,
nsISupportsArray* array)
{
nsArrayEnumerator* enumer = new nsArrayEnumerator(array);
if (enumer == nsnull)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(enumer);
*result = enumer;
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
nsSingletonEnumerator::nsSingletonEnumerator(nsISupports* aValue)
: mValue(aValue)
{
NS_INIT_REFCNT();
NS_IF_ADDREF(mValue);
mConsumed = (mValue ? PR_FALSE : PR_TRUE);
}
nsSingletonEnumerator::~nsSingletonEnumerator()
{
NS_IF_RELEASE(mValue);
}
NS_IMPL_ISUPPORTS(nsSingletonEnumerator, nsISimpleEnumerator::GetIID());
NS_IMETHODIMP
nsSingletonEnumerator::HasMoreElements(PRBool* aResult)
{
NS_PRECONDITION(aResult != 0, "null ptr");
if (! aResult)
return NS_ERROR_NULL_POINTER;
*aResult = !mConsumed;
return NS_OK;
}
NS_IMETHODIMP
nsSingletonEnumerator::GetNext(nsISupports** aResult)
{
NS_PRECONDITION(aResult != 0, "null ptr");
if (! aResult)
return NS_ERROR_NULL_POINTER;
if (mConsumed)
return NS_ERROR_UNEXPECTED;
mConsumed = PR_TRUE;
NS_ADDREF(mValue);
*aResult = mValue;
return NS_OK;
}
extern "C" NS_COM nsresult
NS_NewSingletonEnumerator(nsISimpleEnumerator* *result,
nsISupports* singleton)
{
nsSingletonEnumerator* enumer = new nsSingletonEnumerator(singleton);
if (enumer == nsnull)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(enumer);
*result = enumer;
return NS_OK;
}
////////////////////////////////////////////////////////////////////////
nsAdapterEnumerator::nsAdapterEnumerator(nsIEnumerator* aEnum)
: mEnum(aEnum), mCurrent(0), mStarted(PR_FALSE)
{
NS_INIT_REFCNT();
NS_ADDREF(mEnum);
}
nsAdapterEnumerator::~nsAdapterEnumerator()
{
NS_RELEASE(mEnum);
NS_IF_RELEASE(mCurrent);
}
NS_IMPL_ISUPPORTS(nsAdapterEnumerator, nsISimpleEnumerator::GetIID());
NS_IMETHODIMP
nsAdapterEnumerator::HasMoreElements(PRBool* aResult)
{
nsresult rv;
if (mCurrent) {
*aResult = PR_TRUE;
return NS_OK;
}
if (! mStarted) {
mStarted = PR_TRUE;
rv = mEnum->First();
if (rv == NS_OK) {
mEnum->CurrentItem(&mCurrent);
*aResult = PR_TRUE;
}
else {
*aResult = PR_FALSE;
}
}
else {
*aResult = PR_FALSE;
rv = mEnum->IsDone();
if (rv != NS_OK) {
// We're not done. Advance to the next one.
rv = mEnum->Next();
if (rv == NS_OK) {
mEnum->CurrentItem(&mCurrent);
*aResult = PR_TRUE;
}
}
}
return NS_OK;
}
NS_IMETHODIMP
nsAdapterEnumerator::GetNext(nsISupports** aResult)
{
nsresult rv;
PRBool hasMore;
rv = HasMoreElements(&hasMore);
if (NS_FAILED(rv)) return rv;
if (! hasMore)
return NS_ERROR_UNEXPECTED;
// No need to addref, we "transfer" the ownership to the caller.
*aResult = mCurrent;
mCurrent = 0;
return NS_OK;
}
extern "C" NS_COM nsresult
NS_NewAdapterEnumerator(nsISimpleEnumerator* *result,
nsIEnumerator* enumerator)
{
nsAdapterEnumerator* enumer = new nsAdapterEnumerator(enumerator);
if (enumer == nsnull)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(enumer);
*result = enumer;
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////