www.pudn.com > eMule0.47c-Sources.zip > EnumFields.cpp

///////////////////////////////////////////////////////////////////////////// 
// Copyright (c) 2000 John Adcock.  All rights reserved. 
///////////////////////////////////////////////////////////////////////////// 
// 
// This library is free software; you can redistribute it and/or modify it 
// under the terms of the GNU Library General Public License as published by 
// the Free Software Foundation; either version 2 of the License, or (at your 
// option) any later version. 
// 
// This library is distributed in the hope that it will be useful, but WITHOUT 
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public 
// License for more details. 
// 
// You should have received a copy of the GNU Library General Public License 
// along with this library; if not, write to the Free Software Foundation, 
// Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 
 
// The id3lib authors encourage improvements and optimisations to be sent to 
// the id3lib coordinator.  Please see the README file for details on where to 
// send such submissions.  See the AUTHORS file for a list of people who have 
// contributed to id3lib.  See the ChangeLog file for a list of changes to 
// id3lib.  These files are distributed with id3lib at 
// http://download.sourceforge.net/id3lib/ 
// 
///////////////////////////////////////////////////////////////////////////// 
// EnumFields.cpp : Implementation of DLL Exports. 
///////////////////////////////////////////////////////////////////////////// 
// Change Log 
// 
// Date          Developer             Changes 
// 
// 05 Jan 2000   John Adcock           Original Release     
// 26 Apr 2000   John Adcock           Got working with id3lib 3.7.3 
// 
///////////////////////////////////////////////////////////////////////////// 
 
#include "stdafx.h" 
#include "ID3COM.h" 
#include "EnumFields.h" 
#include  
 
///////////////////////////////////////////////////////////////////////////// 
// CEnumFields 
CEnumFields::CEnumFields() 
{ 
	m_Tag = NULL; 
	m_CurrentNum = 0; 
} 
 
CEnumFields::~CEnumFields() 
{ 
	if(m_Tag != NULL) 
	{ 
		m_Tag->Release(); 
	} 
} 
 
IEnumVARIANT* CEnumFields::CreateObject(IID3ComTag* Tag) 
{ 
	CComObject* pRetVal = new CComObject; 
	pRetVal->m_Tag = Tag; 
	pRetVal->m_Tag->AddRef(); 
	return pRetVal; 
} 
 
STDMETHODIMP CEnumFields::Next(ULONG celt, VARIANT* rgelt, ULONG * pceltFetched) 
{ 
	long NumItems; 
	m_Tag->get_Count(&NumItems); 
	for(long i(0); i < (long)((pceltFetched==NULL)?1:(*pceltFetched)); i++) 
	{ 
		if(m_CurrentNum + i >= NumItems) 
		{ 
			return S_FALSE; 
		} 
		else 
		{ 
			IID3ComFrame* Frame; 
			m_Tag->get_Item(m_CurrentNum + i, &Frame); 
			*(_variant_t*)rgelt = Frame; 
			Frame->Release(); 
			rgelt++; 
		} 
	} 
	m_CurrentNum += ((pceltFetched==NULL)?1:(*pceltFetched)); 
	return S_OK; 
} 
 
STDMETHODIMP CEnumFields::Skip(ULONG celt) 
{ 
	m_CurrentNum += celt; 
	return S_OK; 
} 
 
STDMETHODIMP CEnumFields::Reset(void) 
{ 
	m_CurrentNum = 0; 
	return S_OK; 
} 
 
STDMETHODIMP CEnumFields::Clone(IEnumVARIANT ** ppenum) 
{ 
	CComObject* pRetVal = new CComObject; 
	pRetVal->m_Tag = m_Tag; 
	pRetVal->m_CurrentNum = m_CurrentNum; 
	pRetVal->m_Tag->AddRef(); 
	*ppenum = pRetVal; 
	return S_OK; 
}