#ifndef COMEnumVariant_h
#define COMEnumVariant_h
#include <unknwn.h>
#include "COMVariantSetter.h"
template<typename ContainerType>
class COMEnumVariant : public IEnumVARIANT {
WTF_MAKE_NONCOPYABLE(COMEnumVariant);
public:
static COMEnumVariant* adopt(ContainerType&);
static COMEnumVariant* createInstance(const ContainerType&);
virtual HRESULT STDMETHODCALLTYPE QueryInterface(_In_ REFIID riid, _COM_Outptr_ void** ppvObject);
virtual ULONG STDMETHODCALLTYPE AddRef();
virtual ULONG STDMETHODCALLTYPE Release();
virtual HRESULT STDMETHODCALLTYPE Next(ULONG celt, VARIANT* rgVar, ULONG* pCeltFetched);
virtual HRESULT STDMETHODCALLTYPE Skip(ULONG celt);
virtual HRESULT STDMETHODCALLTYPE Reset();
virtual HRESULT STDMETHODCALLTYPE Clone(_COM_Outptr_opt_ IEnumVARIANT** ppEnum);
private:
COMEnumVariant()
{
}
COMEnumVariant(const ContainerType& container)
: m_container(container)
, m_currentPos(m_container.begin())
{
}
~COMEnumVariant() {}
ULONG m_refCount { 0 };
ContainerType m_container;
typename ContainerType::const_iterator m_currentPos;
};
template<typename ContainerType>
COMEnumVariant<typename ContainerType>* COMEnumVariant<ContainerType>::adopt(ContainerType& container)
{
COMEnumVariant* instance = new COMEnumVariant;
instance->m_container.swap(container);
instance->m_currentPos = instance->m_container.begin();
instance->AddRef();
return instance;
}
template<typename ContainerType>
COMEnumVariant<typename ContainerType>* COMEnumVariant<ContainerType>::createInstance(const ContainerType& container)
{
COMEnumVariant* instance = new COMEnumVariant(container);
instance->AddRef();
return instance;
}
template<typename ContainerType>
HRESULT STDMETHODCALLTYPE COMEnumVariant<ContainerType>::QueryInterface(_In_ REFIID riid, _COM_Outptr_ void** ppvObject)
{
if (!ppvObject)
return E_POINTER;
*ppvObject = nullptr;
if (IsEqualGUID(riid, IID_IUnknown))
*ppvObject = static_cast<COMEnumVariant*>(this);
else if (IsEqualGUID(riid, IID_IEnumVARIANT))
*ppvObject = static_cast<COMEnumVariant*>(this);
else
return E_NOINTERFACE;
AddRef();
return S_OK;
}
template<typename ContainerType>
ULONG STDMETHODCALLTYPE COMEnumVariant<ContainerType>::AddRef()
{
return ++m_refCount;
}
template<typename ContainerType>
ULONG STDMETHODCALLTYPE COMEnumVariant<ContainerType>::Release()
{
ULONG newRef = --m_refCount;
if (!newRef)
delete this;
return newRef;
}
template<typename ContainerType>
HRESULT STDMETHODCALLTYPE COMEnumVariant<ContainerType>::Next(ULONG celt, VARIANT* rgVar, ULONG* pCeltFetched)
{
if (pCeltFetched)
*pCeltFetched = 0;
if (!rgVar)
return E_POINTER;
for (unsigned i = 0 ; i < celt; i++)
::VariantInit(&rgVar[i]);
for (unsigned i = 0; i < celt; i++) {
if (m_currentPos == m_container.end())
return S_FALSE;
COMVariantSetter<ContainerType::ValueType>::setVariant(&rgVar[i], *m_currentPos);
++m_currentPos;
if (pCeltFetched)
(*pCeltFetched)++;
}
return S_OK;
}
template<typename ContainerType>
HRESULT STDMETHODCALLTYPE COMEnumVariant<ContainerType>::Skip(ULONG celt)
{
for (unsigned i = 0; i < celt; i++) {
if (m_currentPos == m_container.end())
return S_FALSE;
++m_currentPos;
}
return S_OK;
}
template<typename ContainerType>
HRESULT STDMETHODCALLTYPE COMEnumVariant<ContainerType>::Reset()
{
m_currentPos = m_container.begin();
return S_OK;
}
template<typename ContainerType>
HRESULT STDMETHODCALLTYPE COMEnumVariant<ContainerType>::Clone(_COM_Outptr_opt_ IEnumVARIANT** ppEnum)
{
if (!ppEnum)
return E_POINTER;
*ppEnum = nullptr;
return E_NOTIMPL;
}
#endif