UNION.CPP

/************************************************************************* 
** 
**  This is a part of the Microsoft Source Code Samples. 
** 
**  Copyright 1992 - 1998 Microsoft Corporation. All rights reserved. 
** 
**  This source code is only intended as a supplement to Microsoft Development 
**  Tools and/or WinHelp documentation.  See these sources for detailed 
**  information regarding the Microsoft samples programs. 
** 
**  OLE Automation TypeLibrary Browse Helper Sample 
** 
**  union.cpp 
** 
**  CUnion implementation 
** 
**  Written by Microsoft Product Support Services, Windows Developer Support 
** 
*************************************************************************/ 
 
#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"   
 
/* 
 * CUnion::Create 
 * 
 * Purpose: 
 *  Creates an instance of the Union automation object and initializes it. 
 * 
 * Parameters:        
 *  ptinfo     TypeInfo of Union. 
 *  ppUnion    Returns Union automation object. 
 * 
 * Return Value: 
 *  HRESULT 
 * 
 */ 
HRESULT  
CUnion::Create(LPTYPEINFO ptinfo, CUnion FAR* FAR* ppUnion)  
{    
    HRESULT hr; 
    CUnion FAR* pUnion = NULL; 
      
    *ppUnion = NULL; 
     
    // Create application object. 
    pUnion = new CUnion(); 
    if (pUnion == NULL) 
    { 
        hr = E_OUTOFMEMORY;  
        goto error; 
    }    
    // Load type information for the object from type library.  
    hr = pUnion->LoadTypeInfo(IID_IUnion); 
    if (FAILED(hr)) 
        goto error;   
    // Initialise base class, CTypeInfo.     
    hr = pUnion->_InitTypeInfo(ptinfo); 
    if (FAILED(hr)) 
        goto error; 
     
    ptinfo->AddRef(); 
    pUnion->m_ptinfo = ptinfo; 
 
#ifdef _DEBUG   
    lstrcpyn(pUnion->m_szClassName, TEXT("Union"), 100); 
#endif 
         
    *ppUnion = pUnion; 
    return NOERROR; 
     
error: 
    if (pUnion == NULL) return E_OUTOFMEMORY; 
    if (pUnion->m_ptinfo) pUnion->m_ptinfo->Release(); 
          
    // Set to NULL to prevent destructor from attempting to free again   
    pUnion->m_ptinfo = NULL; 
     
    delete pUnion; 
    return hr; 
} 
 
/* 
 * CUnion::CUnion 
 * 
 * Purpose: 
 *  Constructor for CUnion object. Initializes members to NULL. 
 * 
 */ 
CUnion::CUnion() 
{ 
    m_pdispMembers = NULL;       
    m_ptinfo = NULL; 
} 
 
/* 
 * CUnion::~CUnion 
 * 
 * Purpose: 
 *  Destructor for CUnion object.  
 * 
 */ 
CUnion::~CUnion() 
{ 
    if (m_pdispMembers) m_pdispMembers->Release(); 
    if (m_ptinfo) m_ptinfo->Release(); 
}   
 
STDMETHODIMP_(REFCLSID) 
CUnion::GetInterfaceID() 
{ 
    return IID_IUnion; 
} 
 
/* 
 * CUnion:: 
 * 
 * Purpose: 
 *   
 * 
 */ 
 
STDMETHODIMP_(ICollection FAR*) 
CUnion::get_Members()      
{     
    HRESULT hr; 
    CProperty FAR* pProperty; 
    CCollection FAR* pCollection = NULL; 
    LPDISPATCH pdisp; 
    LPVARDESC pvardesc = NULL;    
    LPTYPEATTR ptypeattr = NULL; 
    unsigned short n; 
     
    if (m_pdispMembers == NULL) 
    {    
        // Create collection of union memebers.  
        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;}    
        for (n=0; n<ptypeattr->cVars; n++) 
        {        
            hr = m_ptinfo->GetVarDesc(n, &pvardesc);    
            if (FAILED(hr)) 
                {RaiseException(IDS_Unexpected); goto error;}    
            hr = CProperty::Create(m_ptinfo, pvardesc, &pProperty); 
            if (FAILED(hr)) 
                {RaiseException(IDS_Unexpected); goto error;}     
            m_ptinfo->ReleaseVarDesc(pvardesc);  
            pvardesc = NULL; 
            pProperty->QueryInterface(IID_IDispatch, (void FAR* FAR*)&pdisp); 
            pCollection->Add(pdisp);    
            pdisp->Release(); 
        } 
        pCollection->QueryInterface(IID_IDispatch, (void FAR* FAR*)&pdisp); 
        m_pdispMembers = pdisp;     
        m_ptinfo->ReleaseTypeAttr(ptypeattr);  
    } 
    m_pdispMembers->AddRef(); 
    return (ICollection FAR*)m_pdispMembers; 
 
error:   
    if (ptypeattr) m_ptinfo->ReleaseTypeAttr(ptypeattr);    
    if (pCollection) delete pCollection;    
    if (pvardesc) m_ptinfo->ReleaseVarDesc(pvardesc);    
    return NULL; 
}