Source code of Windows XP (NT5)
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//////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 1999-2000 Microsoft Corporation
//
// Module Name:
// CStr.cpp
//
// Description:
// Contains the definition of the CStr class.
//
// Documentation:
// TODO: Add pointer to external documentation later.
//
// Maintained By:
// Vij Vasu (Vvasu) 08-MAR-2000
//
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
// Include Files
//////////////////////////////////////////////////////////////////////////////
// The header file of this class
#include "CStr.h"
// For the exceptions thrown by CStr
#include "CException.h"
//////////////////////////////////////////////////////////////////////////////
//++
//
// void
// CStr::LoadString()
//
// Description:
// Lookup a string in a string table using a string id.
//
// Arguments:
// hInstIn
// Instance handle of the module containing the string table resource.
//
// uiStringIdIn
// Id of the string to look up
//
// Return Value:
// None.
//
// Exceptions Thrown:
// CException
// If the lookup fails.
//
// Remarks:
// This function cannot load a zero length string.
//--
//////////////////////////////////////////////////////////////////////////////
void
CStr::LoadString( HINSTANCE hInstIn, UINT nStringIdIn )
{
UINT uiCurrentSize = 0;
TCHAR * pszCurrentString = NULL;
UINT uiReturnedStringLen = 0;
do
{
// Free the string allocated in the previous iteration.
delete pszCurrentString;
// Grow the current string by an arbitrary amount.
uiCurrentSize += 256;
pszCurrentString = new TCHAR[ uiCurrentSize ];
if ( pszCurrentString == NULL )
{
THROW_EXCEPTION( E_OUTOFMEMORY );
} // if: the memory allocation has failed
uiReturnedStringLen = ::LoadString(
hInstIn
, nStringIdIn
, pszCurrentString
, uiCurrentSize
);
if ( uiReturnedStringLen == 0 )
{
HRESULT hrRetVal = TW32( GetLastError() );
hrRetVal = HRESULT_FROM_WIN32( hrRetVal );
delete pszCurrentString;
THROW_EXCEPTION( hrRetVal );
} // if: LoadString() had an error
++uiReturnedStringLen;
}
while( uiCurrentSize <= uiReturnedStringLen );
// Free the existing string.
Free();
// Store details about the newly allocated string in the member variables.
m_pszData = pszCurrentString;
m_nLen = uiReturnedStringLen;
m_cchBufferSize = uiCurrentSize;
} //*** CStr::LoadString()
//////////////////////////////////////////////////////////////////////////////
//++
//
// void
// CStr::AllocateBuffer( UINT cchBufferSizeIn )
//
// Description:
// Allocate a buffer of cchBufferSizeIn characters. If the existing buffer is not
// smaller than cchBufferSizeIn characters, nothing is done. Otherwise, a new
// buffer is allocated and the old contents are filled into this buffer.
//
// Arguments:
// cchBufferSizeIn
// Required size of the new buffer in characters.
//
// Return Value:
// None.
//
// Exceptions Thrown:
// CException
// If the memory allocation fails.
//
//--
//////////////////////////////////////////////////////////////////////////////
void
CStr::AllocateBuffer( UINT cchBufferSizeIn )
{
// Check if the buffer is already big enough
if ( m_cchBufferSize < cchBufferSizeIn )
{
TCHAR * psz = new TCHAR[ cchBufferSizeIn ];
if ( psz == NULL )
{
THROW_EXCEPTION( E_OUTOFMEMORY );
} // if: memory allocation failed
// Copy the old data into the new buffer.
_tcsncpy( psz, m_pszData, m_nLen + 1 );
if ( m_pszData != &ms_chNull )
{
delete m_pszData;
} // if: the pointer was dynamically allocated
m_pszData = psz;
m_cchBufferSize = cchBufferSizeIn;
}
} //*** AllocateBuffer()