The Mini Shell Extension Framework – Part III

//
// (C) Copyright by Victor Derks <vba64@xs4all.nl>
//
// See README.TXT for the details of the software licence.
//
#pragma once


#include "vvvitem.h"
#include "../include/shlobjhidden.h"


// Purpose: copy policy class: required for the ATL::CComEnumOnSTL template.
class CVVVItemToPidl
{
public:
	static void init(ITEMIDLIST** /*p*/)
	{
		// No init needed.
	}


	static HRESULT copy(ITEMIDLIST** pTo, const CVVVItem* pFrom)
	{
		ATLTRACE2(atlTraceCOM, 0, _T("CVVVItemToPidl::copy (id=%p)\n"), pFrom->GetID());
		*pTo = pFrom->CreateShellItemIdList();
		return (NULL == *pTo) ? E_OUTOFMEMORY : S_OK;
	}


	static void destroy(ITEMIDLIST** p)
	{
		SHFree(p);
	}
};


class CEnumIDList :
	public CComEnumOnSTL<IEnumIDList,
	                     &IID_IEnumIDList, // name and IID of enumerator interface
	                     ITEMIDLIST*,      // type of object to return
	                     CVVVItemToPidl,   // copy policy class
	                     CVVVItems>        // type of collection holding the data
{
public:

	typedef std::auto_ptr<CVVVItems> CVVVItemsPtr;

	static CComPtr<IEnumIDList> CreateInstance(IUnknown* punknown, CVVVItemsPtr qitems)
	{
		CComObject<CEnumIDList>* pEnum;
		RaiseExceptionIfFailed(CComObject<CEnumIDList>::CreateInstance(&pEnum));

		static_cast<CEnumIDList*>(pEnum)->Init(punknown, qitems);

		CComPtr<IEnumIDList> renumidlist(pEnum);
		ATLASSERT(renumidlist != NULL);

		return renumidlist;
	}


	CEnumIDList() throw()
	{
		ATLTRACE2(atlTraceCOM, 0, _T("CEnumIDList::CEnumIDList (instance=%p)\n"), this);
	}


	~CEnumIDList() throw()
	{
		ATLTRACE2(atlTraceCOM, 0, _T("CEnumIDList::~CEnumIDList (instance=%p)\n"), this);
	}

private:

	// Purpose: 'Constructor' for our ATL based COM object.
	void Init(IUnknown* pUnkForRelease, CVVVItemsPtr qitems) throw()
	{
		m_qitems = qitems;

		ATLVERIFY(SUCCEEDED(__super::Init(pUnkForRelease, *m_qitems)));
	}

	// Member variables.
	CVVVItemsPtr m_qitems;
};