HELPERS.H

//--------------------------------------------------------------------------- 
// Helpers.h 
//--------------------------------------------------------------------------- 
// General OLE Automation helper functions. 
//--------------------------------------------------------------------------- 
// (C) Copyright 1995-1997 by Microsoft Corporation.  All rights reserved. 
// 
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF  
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO  
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A  
// PARTICULAR PURPOSE. 
//--------------------------------------------------------------------------- 
 
 
//--------------------------------------------------------------------------- 
// To make the OLE-related code easier to read 
//--------------------------------------------------------------------------- 
#define CHECK(x)       { hr = (x);  if (hr) { FAIL("Bad hr"); goto CleanUp; } } 
#define CHECKSZ(x,sz)  { hr = (x);  if (hr) { FAIL(sz);       goto CleanUp; } } 
#define CHECKCL(x)     { hr = (x);  if (hr) { FAIL("Bad hr"); goto CheckLoop; } } 
#define ARGSZ(f,sz)    {            if (f)  { FAIL(sz);       return E_INVALIDARG; } } 
#define CHECKOS(x) { if (ERROR_SUCCESS!=(x)) { FAIL("Bad"); hr=E_FAIL; goto CleanUp; } } 
 
#define RELEASEPTRTYPE(p,typ) \ 
  {                           \ 
    if (p)                    \ 
      {                       \ 
      typ *__punk = (p);      \ 
      (p) = NULL;             \ 
      __punk->Release();      \ 
      }                       \ 
  } 
 
#define RELEASEPTR(p)     RELEASEPTRTYPE(p,IUnknown) 
 
 
//--------------------------------------------------------------------------- 
// Allocates a temporary buffer that will disappear when it goes out of scope 
// NOTE: Be careful of that-- make sure you use the string in the same or 
// nested scope in which you created this buffer.  People should not use this 
// class directly; use the macro(s) below. 
//--------------------------------------------------------------------------- 
class TempBuffer 
  { 
  public: 
    TempBuffer(ULONG cb) 
      { 
      m_fAlloc = (cb > 120); 
      if (m_fAlloc) 
        m_pbBuf = new char[cb]; 
      else 
        m_pbBuf = &m_szBufT; 
      } 
    ~TempBuffer() 
      { if (m_pbBuf && m_fAlloc) delete m_pbBuf; } 
    void *GetBuffer(void) 
      { return m_pbBuf; } 
 
  private: 
    void *m_pbBuf; 
    char  m_szBufT[120];  // We'll use this temp buffer for small cases. 
    int   m_fAlloc; 
  }; 
 
 
//--------------------------------------------------------------------------- 
// String helpers. 
//--------------------------------------------------------------------------- 
// Given and ANSI String, copy it into a wide buffer. 
// NOTE: Be careful about scoping when using this macro! 
// 
// How to use the below two macros: 
// 
//  ... 
//  LPSTR pszA; 
//  pszA = MyGetpszAnsiingRoutine(); 
//  MAKE_WIDEPTR_FROMANSI(pwsz, pszA); 
//  MyUseWideStringRoutine(pwsz); 
//  ... 
// 
// Similarily for MAKE_ANSIPTR_FROMWIDE().  Note that the first param does 
// not have to be declared, and no clean up must be done. 
//--------------------------------------------------------------------------- 
#define UNICODE_FROM_ANSI(pwszUnicode, pszAnsi, cb) \ 
    MultiByteToWideChar(CP_ACP, 0, pszAnsi, -1, pwszUnicode, cb); 
 
#define MAKE_WIDEPTR_FROMANSI(ptrname, pszAnsi) \ 
    char *__psz##ptrname = pszAnsi?pszAnsi:""; \ 
    long __l##ptrname = (lstrlen(__psz##ptrname) + 1) * sizeof(WCHAR); \ 
    TempBuffer __TempBuffer##ptrname(__l##ptrname); \ 
    MultiByteToWideChar(CP_ACP, 0, __psz##ptrname, -1, (LPWSTR)__TempBuffer##ptrname.GetBuffer(), __l##ptrname); \ 
    LPWSTR ptrname = (LPWSTR)__TempBuffer##ptrname.GetBuffer() 
 
#define MAKE_ANSIPTR_FROMWIDE(ptrname, pwszUnicode) \ 
    WCHAR *__pwsz##ptrname = pwszUnicode?pwszUnicode:L""; \ 
    long __l##ptrname = (lstrlenW(__pwsz##ptrname) + 1) * sizeof(char); \ 
    TempBuffer __TempBuffer##ptrname(__l##ptrname); \ 
    WideCharToMultiByte(CP_ACP, 0, __pwsz##ptrname, -1, (LPSTR)__TempBuffer##ptrname.GetBuffer(), __l##ptrname, NULL, NULL); \ 
    LPSTR ptrname = (LPSTR)__TempBuffer##ptrname.GetBuffer() 
 
//--- EOF -------------------------------------------------------------------