CONSTANT.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 Constant Browse Helper Sample 
** 
**  Constant.cpp 
** 
**  CConstant 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"   
 
/* 
 * CConstant::Create 
 * 
 * Purpose: 
 *  Creates an instance of the Constant automation object and initializes it. 
 * 
 * Parameters:  
 *  ptinfo        TypeInfo of which this constant is an element. 
 *  pvardesc      VARDESC that describes this constant. 
 *  ppConstant    Returns Constant automation object. 
 * 
 * Return Value: 
 *  HRESULT 
 * 
 */ 
HRESULT  
CConstant::Create(LPTYPEINFO ptinfo, LPVARDESC pvardesc, CConstant FAR* FAR* ppConstant)  
{    
    HRESULT hr; 
    CConstant FAR* pConstant = NULL;    
    BSTR bstr;   
    unsigned int cNames;         
    CTypeDesc FAR* pTypeDesc = NULL; 
      
    *ppConstant = NULL; 
     
    // Create object. 
    pConstant = new CConstant(); 
    if (pConstant == NULL) 
    { 
        hr = E_OUTOFMEMORY;  
        goto error; 
    }    
     
    // Load type information for the application object from type library.  
    hr = pConstant->LoadTypeInfo(IID_IConstant); 
    if (FAILED(hr)) 
        goto error;  
     
    pConstant->m_memid = pvardesc->memid;  
    ptinfo->GetNames(pvardesc->memid, &bstr, 1, &cNames);     
    pConstant->m_bstrName = bstr;         
     
    // Type of constant.     
    hr = CTypeDesc::Create(ptinfo, &pvardesc->elemdescVar.tdesc, &pTypeDesc); 
    if (FAILED(hr)) 
        goto error; 
    pTypeDesc->QueryInterface(IID_IDispatch, (LPVOID FAR*)&pConstant->m_pdispTypeDesc);   
     
    // Constant value. 
    if (pvardesc->varkind == VAR_CONST) 
        pConstant->m_vValue = *pvardesc->lpvarValue; 
    else goto error;  
     
    hr = ptinfo->GetDocumentation(pvardesc->memid, NULL, &pConstant->m_bstrDocumentation, 
             &pConstant->m_ulHelpContext, &pConstant->m_bstrHelpFile);     
    if (FAILED(hr)) 
        goto error; 
 
#ifdef _DEBUG   
    lstrcpyn(pConstant->m_szClassName, TEXT("Constant"), 100); 
#endif  
         
    *ppConstant = pConstant; 
    return NOERROR; 
     
error:                         
    if (pConstant == NULL) return E_OUTOFMEMORY; 
    if (pConstant->m_bstrName) SysFreeString(pConstant->m_bstrName); 
    if (pConstant->m_bstrDocumentation) SysFreeString(pConstant->m_bstrDocumentation); 
    if (pConstant->m_bstrHelpFile) SysFreeString(pConstant->m_bstrHelpFile);    
     
    // Set to NULL to prevent destructor from attempting to free again 
    pConstant->m_bstrName = NULL; 
    pConstant->m_bstrDocumentation = NULL; 
    pConstant->m_bstrHelpFile = NULL;     
 
    delete pConstant; 
    return hr; 
} 
 
/* 
 * CConstant::CConstant 
 * 
 * Purpose: 
 *  Constructor for CConstant object. Initializes members to NULL. 
 * 
 */ 
CConstant::CConstant() 
{    
    m_bstrName = NULL; 
    m_bstrDocumentation = NULL; 
    m_bstrHelpFile = NULL;    
    m_pdispTypeDesc = NULL; 
} 
 
/* 
 * CConstant::~CConstant 
 * 
 * Purpose: 
 *  Destructor for CConstant object.  
 * 
 */ 
CConstant::~CConstant() 
{     
     if (m_bstrName) SysFreeString(m_bstrName); 
     if (m_bstrDocumentation) SysFreeString(m_bstrDocumentation); 
     if (m_bstrHelpFile) SysFreeString(m_bstrHelpFile);  
     if (m_pdispTypeDesc) m_pdispTypeDesc->Release(); 
} 
 
STDMETHODIMP_(REFCLSID) 
CConstant::GetInterfaceID() 
{ 
    return IID_IConstant; 
} 
 
 
STDMETHODIMP_(BSTR) 
CConstant::get_Name() 
{ 
    return SysAllocString(m_bstrName); 
}    
 
STDMETHODIMP_(BSTR) 
CConstant::get_Documentation()      
{ 
    return SysAllocString(m_bstrDocumentation); 
}   
 
STDMETHODIMP_(long) 
CConstant::get_HelpContext()      
{ 
    return (long)m_ulHelpContext; 
} 
 
STDMETHODIMP_(BSTR) 
CConstant::get_HelpFile()      
{ 
    return SysAllocString(m_bstrHelpFile); 
}    
 
STDMETHODIMP_(ITypeDesc FAR*) 
CConstant::get_Type() 
{ 
    m_pdispTypeDesc->AddRef(); 
    return (ITypeDesc FAR*)m_pdispTypeDesc; 
}  
 
STDMETHODIMP_(VARIANT) 
CConstant::get_Value() 
{ 
    return m_vValue; 
}     
 
STDMETHODIMP_(MEMBERID) 
CConstant::get_Memberid() 
{ 
    return m_memid; 
} 
 
STDMETHODIMP_(OBJTYPE) 
CConstant::get_Kind() 
{    
    return TYPE_CONSTANT; 
}