bool bailin::MemBuffer::Append(const char* pData, int nLen /*= 0*/ )
{
if (NULL == pData)
{
return false;
}
if (nLen <= 0)
{
// It means pData is terminate with \0
if ((nLen = strlen(pData)) <= 0)
{
return false;
}
}
// 补上\0的位置
if (m_nCurLen + nLen + 1 > m_nMaxLen)
{
if(!ReAllocBuffer(nLen + 1))
{
return false;
}
}
memcpy(m_pBuffer + m_nCurLen, pData, nLen);
m_nCurLen += nLen;
*(m_pBuffer + m_nCurLen) = 0;
return true;
}
bailin::MemBuffer::MemBuffer(int nInitLen /* = 16 */)
{
m_pBuffer = NULL;
m_nCurLen = 0;
m_nMaxLen = 0;
ReAllocBuffer(nInitLen);
}
bailin::MemBuffer::MemBuffer( const char* pData, int nLen /*= 0*/ )
{
m_pBuffer = NULL;
m_nCurLen = 0;
m_nMaxLen = 0;
if (NULL != pData)
{
Append(pData, nLen);
}
else
{
ReAllocBuffer(32);
}
}
STDMETHODIMP CDataCallback::BandedDataCallback(
LONG lReason,
LONG lStatus,
LONG lPercentComplete,
LONG lOffset,
LONG lLength,
LONG, LONG,
PBYTE pbBuffer
)
{
HRESULT hr;
// Parse the message
switch (lReason)
{
case IT_MSG_DATA_HEADER:
{
PWIA_DATA_CALLBACK_HEADER pHeader = (PWIA_DATA_CALLBACK_HEADER) pbBuffer;
// Determine if this is a BMP transfer
m_bBMP = pHeader->guidFormatID == WiaImgFmt_MEMORYBMP || pHeader->guidFormatID == WiaImgFmt_BMP;
// For WiaImgFmt_MEMORYBMP transfers, WIA does not send a BITMAPFILEHEADER before the data.
// In this program, we desire all BMP files to contain a BITMAPFILEHEADER, so add it manually
m_nHeaderSize = pHeader->guidFormatID == WiaImgFmt_MEMORYBMP ? sizeof(BITMAPFILEHEADER) : 0;
// Allocate memory for the image if the size is given in the header
if (pHeader != NULL && pHeader->lBufferSize != 0)
{
hr = ReAllocBuffer(m_nHeaderSize + pHeader->lBufferSize);
if (FAILED(hr))
{
return hr;
}
}
break;
}
case IT_MSG_DATA:
{
// Invoke the callback function
hr = m_pfnProgressCallback(lStatus, lPercentComplete, m_pProgressCallbackParam);
if (FAILED(hr) || hr == S_FALSE)
{
return hr;
}
// If the buffer is not allocated yet and this is the first block,
// and the transferred image is in BMP format, allocate the buffer
// according to the size information in the bitmap header
if (m_pStream == NULL && lOffset == 0 && m_bBMP)
{
LONG nBufferSize = BitmapUtil::GetBitmapSize(pbBuffer);
if (nBufferSize != 0)
{
hr = ReAllocBuffer(m_nHeaderSize + nBufferSize);
if (FAILED(hr))
{
return hr;
}
}
}
if (m_nHeaderSize + lOffset + lLength < 0)
{
return E_OUTOFMEMORY;
}
// If the transfer goes past the buffer, try to expand it
if (m_nHeaderSize + lOffset + lLength > m_nDataSize)
{
hr = ReAllocBuffer(m_nHeaderSize + lOffset + lLength);
if (FAILED(hr))
{
return hr;
}
}
// copy the transfer buffer
hr = CopyToBuffer(m_nHeaderSize + lOffset, pbBuffer, lLength);
if (FAILED(hr))
{
return hr;
}
break;
}
case IT_MSG_STATUS:
{
// Invoke the callback function
hr = m_pfnProgressCallback(lStatus, lPercentComplete, m_pProgressCallbackParam);
if (FAILED(hr) || hr == S_FALSE)
{
return hr;
}
break;
}
case IT_MSG_TERMINATION:
case IT_MSG_NEW_PAGE:
{
if (m_pStream != NULL)
{
// For BMP files, we should validate the the image header
// So, obtain the memory buffer from the stream
if (m_bBMP)
{
// Since the stream is created using CreateStreamOnHGlobal,
// we can get the memory buffer with GetHGlobalFromStream.
HGLOBAL hBuffer;
hr = GetHGlobalFromStream(m_pStream, &hBuffer);
if (FAILED(hr))
{
return hr;
}
PBITMAPFILEHEADER pBuffer = (PBITMAPFILEHEADER) GlobalLock(hBuffer);
if (pBuffer == NULL)
{
return HRESULT_FROM_WIN32(GetLastError());
}
// Some scroll-fed scanners may return 0 as the bitmap height
// In this case, calculate the image height and modify the header
BitmapUtil::FixBitmapHeight(pBuffer + 1, m_nDataSize, TRUE);
// For WiaImgFmt_MEMORYBMP transfers, the WIA service does not
// include a BITMAPFILEHEADER preceeding the bitmap data.
// In this case, fill in the BITMAPFILEHEADER structure.
if (m_nHeaderSize != 0)
{
BitmapUtil::FillBitmapFileHeader(pBuffer + 1, pBuffer);
}
GlobalUnlock(hBuffer);
}
// Store this buffer in the successfully transferred images array
hr = StoreBuffer();
if (FAILED(hr))
{
return hr;
}
}
break;
}
}
return S_OK;
}
