ENUM.CPP (BROWSEH OLE Sample)

/*************************************************************************

• OLE Automation TypeLibrary Browse Helper Sample

• enum.cpp

• CEnum implementation

• Written by Microsoft Product Support Services, Windows Developer Support

• (c) Copyright Microsoft Corp. 1994 All Rights Reserved

• ***********************************************************************/

#include <windows.h>

#include <windowsx.h>

#ifdef WIN16

#include <ole2.h>

#include <compobj.h>

#include <dispatch.h>

#include <variant.h>

#include <olenls.h>

#endif

#include "browseh.h"

/*

* CEnum::Create

*

* Purpose:

* Creates an instance of the Enum automation object and initializes it.

*

* Parameters:

* ptinfo TypeInfo of Enum.

* ppEnum Returns Enum automation object.

*

* Return Value:

* HRESULT

*

*/

HRESULT

CEnum::Create(LPTYPEINFO ptinfo, CEnum FAR* FAR* ppEnum)

{

HRESULT hr;

CEnum FAR* pEnum = NULL;

*ppEnum = NULL;

// Create object.

pEnum = new CEnum();

if (pEnum == NULL)

{

hr = ResultFromScode(E_OUTOFMEMORY);

goto error;

}

// Load type information for the object from type library.

hr = pEnum->LoadTypeInfo(IID_IEnum);

if (FAILED(hr))

goto error;

// Ask base class (CTypeInfo) to initialize.

hr = pEnum->_InitTypeInfo(ptinfo);

if (FAILED(hr))

goto error;

ptinfo->AddRef();

pEnum->m_ptinfo = ptinfo;

#ifdef _DEBUG

lstrcpyn(pEnum->m_szClassName, TEXT("Enum"), 100);

#endif

*ppEnum = pEnum;

return NOERROR;

error:

if (pEnum == NULL) return ResultFromScode(E_OUTOFMEMORY);

if (pEnum->m_ptinfo) pEnum->m_ptinfo->Release();

// Set to NULL to prevent destructor from attempting to free again

pEnum->m_ptinfo = NULL;

delete pEnum;

return hr;

}

/*

* CEnum::CEnum

*

* Purpose:

* Constructor for CEnum object. Initializes members to NULL.

*

*/

CEnum::CEnum()

{

m_pdispElements = NULL;

m_ptinfo = NULL;

}

/*

* CEnum::~CEnum

*

* Purpose:

* Destructor for CEnum object.

*

*/

CEnum::~CEnum()

{

if (m_pdispElements) m_pdispElements->Release();

if (m_ptinfo) m_ptinfo->Release();

}

STDMETHODIMP_(REFCLSID)

CEnum::GetInterfaceID()

{

return IID_IEnum;

}

STDMETHODIMP_(ICollection FAR*)

CEnum::get_Elements()

{

HRESULT hr;

CConstant FAR* pConstant;

CCollection FAR* pCollection = NULL;

LPDISPATCH pdisp;

LPVARDESC pvardesc = NULL;

LPTYPEATTR ptypeattr = NULL;

unsigned short n;

if (m_pdispElements == NULL)

{

hr = m_ptinfo->GetTypeAttr(&ptypeattr);

if (FAILED(hr))

{RaiseException(IDS_Unexpected); return NULL;}

hr = CCollection::Create(ptypeattr->cVars, 0, &pCollection);

if (FAILED(hr))

{RaiseException(IDS_Unexpected); goto error;}

// Enumerate enum constants and return a collection of these.

for (n=0; n<ptypeattr->cVars; n++)

{

hr = m_ptinfo->GetVarDesc(n, &pvardesc);

if (FAILED(hr))

{RaiseException(IDS_Unexpected); goto error;}

hr = CConstant::Create(m_ptinfo, pvardesc, &pConstant);

if (FAILED(hr))

{RaiseException(IDS_Unexpected); goto error;}

m_ptinfo->ReleaseVarDesc(pvardesc);

pvardesc = NULL;

pConstant->QueryInterface(IID_IDispatch, (void FAR* FAR*)&pdisp);

pCollection->Add(pdisp);

pdisp->Release();

}

pCollection->QueryInterface(IID_IDispatch, (void FAR* FAR*)&pdisp);

m_pdispElements = pdisp;

m_ptinfo->ReleaseTypeAttr(ptypeattr);

}

m_pdispElements->AddRef();

return (ICollection FAR*)m_pdispElements;

error:

if (ptypeattr) m_ptinfo->ReleaseTypeAttr(ptypeattr);

if (pCollection) delete pCollection;

if (pvardesc) m_ptinfo->ReleaseVarDesc(pvardesc);

return NULL;

}

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