gecko-dev/xpcom/ds/nsStringEnumerator.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** 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 String Enumerator.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corp.
* Portions created by the Initial Developer are Copyright (C) 2003
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Alec Flett <alecf@netscape.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 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 ***** */
#include "nsStringEnumerator.h"
#include "prtypes.h"
#include "nsCRT.h"
#include "nsString.h"
#include "nsReadableUtils.h"
#include "nsISimpleEnumerator.h"
#include "nsSupportsPrimitives.h"
//
// nsStringEnumerator
//
class nsStringEnumerator : public nsIStringEnumerator,
public nsIUTF8StringEnumerator,
public nsISimpleEnumerator
{
public:
nsStringEnumerator(const nsTArray<nsString>* aArray, PRBool aOwnsArray) :
mArray(aArray), mIndex(0), mOwnsArray(aOwnsArray), mIsUnicode(PR_TRUE)
{}
nsStringEnumerator(const nsTArray<nsCString>* aArray, PRBool aOwnsArray) :
mCArray(aArray), mIndex(0), mOwnsArray(aOwnsArray), mIsUnicode(PR_FALSE)
{}
nsStringEnumerator(const nsTArray<nsString>* aArray, nsISupports* aOwner) :
mArray(aArray), mIndex(0), mOwner(aOwner), mOwnsArray(PR_FALSE), mIsUnicode(PR_TRUE)
{}
nsStringEnumerator(const nsTArray<nsCString>* aArray, nsISupports* aOwner) :
mCArray(aArray), mIndex(0), mOwner(aOwner), mOwnsArray(PR_FALSE), mIsUnicode(PR_FALSE)
{}
NS_DECL_ISUPPORTS
NS_DECL_NSIUTF8STRINGENUMERATOR
// have to declare nsIStringEnumerator manually, because of
// overlapping method names
NS_IMETHOD GetNext(nsAString& aResult);
NS_DECL_NSISIMPLEENUMERATOR
private:
~nsStringEnumerator() {
if (mOwnsArray) {
// const-casting is safe here, because the NS_New*
// constructors make sure mOwnsArray is consistent with
// the constness of the objects
if (mIsUnicode)
delete const_cast<nsTArray<nsString>*>(mArray);
else
delete const_cast<nsTArray<nsCString>*>(mCArray);
}
}
union {
const nsTArray<nsString>* mArray;
const nsTArray<nsCString>* mCArray;
};
inline PRUint32 Count() {
return mIsUnicode ? mArray->Length() : mCArray->Length();
}
PRUint32 mIndex;
// the owner allows us to hold a strong reference to the object
// that owns the array. Having a non-null value in mOwner implies
// that mOwnsArray is PR_FALSE, because we rely on the real owner
// to release the array
nsCOMPtr<nsISupports> mOwner;
PRPackedBool mOwnsArray;
PRPackedBool mIsUnicode;
};
NS_IMPL_ISUPPORTS3(nsStringEnumerator,
nsIStringEnumerator,
nsIUTF8StringEnumerator,
nsISimpleEnumerator)
NS_IMETHODIMP
nsStringEnumerator::HasMore(PRBool* aResult)
{
NS_ENSURE_ARG_POINTER(aResult);
*aResult = mIndex < Count();
return NS_OK;
}
NS_IMETHODIMP
nsStringEnumerator::HasMoreElements(PRBool* aResult)
{
return HasMore(aResult);
}
NS_IMETHODIMP
nsStringEnumerator::GetNext(nsISupports** aResult)
{
if (mIsUnicode) {
nsSupportsStringImpl* stringImpl = new nsSupportsStringImpl();
if (!stringImpl) return NS_ERROR_OUT_OF_MEMORY;
stringImpl->SetData(mArray->ElementAt(mIndex++));
*aResult = stringImpl;
}
else {
nsSupportsCStringImpl* cstringImpl = new nsSupportsCStringImpl();
if (!cstringImpl) return NS_ERROR_OUT_OF_MEMORY;
cstringImpl->SetData(mCArray->ElementAt(mIndex++));
*aResult = cstringImpl;
}
NS_ADDREF(*aResult);
return NS_OK;
}
NS_IMETHODIMP
nsStringEnumerator::GetNext(nsAString& aResult)
{
NS_ENSURE_TRUE(mIndex < Count(), NS_ERROR_UNEXPECTED);
if (mIsUnicode)
aResult = mArray->ElementAt(mIndex++);
else
CopyUTF8toUTF16(mCArray->ElementAt(mIndex++), aResult);
return NS_OK;
}
NS_IMETHODIMP
nsStringEnumerator::GetNext(nsACString& aResult)
{
NS_ENSURE_TRUE(mIndex < Count(), NS_ERROR_UNEXPECTED);
if (mIsUnicode)
CopyUTF16toUTF8(mArray->ElementAt(mIndex++), aResult);
else
aResult = mCArray->ElementAt(mIndex++);
return NS_OK;
}
template<class T>
static inline nsresult
StringEnumeratorTail(T** aResult NS_INPARAM)
{
if (!*aResult)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*aResult);
return NS_OK;
}
//
// constructors
//
NS_COM nsresult
NS_NewStringEnumerator(nsIStringEnumerator** aResult,
const nsTArray<nsString>* aArray, nsISupports* aOwner)
{
NS_ENSURE_ARG_POINTER(aResult);
NS_ENSURE_ARG_POINTER(aArray);
*aResult = new nsStringEnumerator(aArray, aOwner);
return StringEnumeratorTail(aResult);
}
NS_COM nsresult
NS_NewUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
const nsTArray<nsCString>* aArray, nsISupports* aOwner)
{
NS_ENSURE_ARG_POINTER(aResult);
NS_ENSURE_ARG_POINTER(aArray);
*aResult = new nsStringEnumerator(aArray, aOwner);
return StringEnumeratorTail(aResult);
}
NS_COM nsresult
NS_NewAdoptingStringEnumerator(nsIStringEnumerator** aResult,
nsTArray<nsString>* aArray)
{
NS_ENSURE_ARG_POINTER(aResult);
NS_ENSURE_ARG_POINTER(aArray);
*aResult = new nsStringEnumerator(aArray, PR_TRUE);
return StringEnumeratorTail(aResult);
}
NS_COM nsresult
NS_NewAdoptingUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
nsTArray<nsCString>* aArray)
{
NS_ENSURE_ARG_POINTER(aResult);
NS_ENSURE_ARG_POINTER(aArray);
*aResult = new nsStringEnumerator(aArray, PR_TRUE);
return StringEnumeratorTail(aResult);
}
// const ones internally just forward to the non-const equivalents
NS_COM nsresult
NS_NewStringEnumerator(nsIStringEnumerator** aResult,
const nsTArray<nsString>* aArray)
{
NS_ENSURE_ARG_POINTER(aResult);
NS_ENSURE_ARG_POINTER(aArray);
*aResult = new nsStringEnumerator(aArray, PR_FALSE);
return StringEnumeratorTail(aResult);
}
NS_COM nsresult
NS_NewUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
const nsTArray<nsCString>* aArray)
{
NS_ENSURE_ARG_POINTER(aResult);
NS_ENSURE_ARG_POINTER(aArray);
*aResult = new nsStringEnumerator(aArray, PR_FALSE);
return StringEnumeratorTail(aResult);
}