OVERLAYCALLBACK

L_INT EXT_CALLBACK MyOverlayCallback(pFILEOVERLAYCALLBACKDATA pOverlayCallbackData, L_VOID* pUserData) 
{ 
   UNREFERENCED_PARAMETER(pUserData); 
   L_TCHAR szBuffer[800]; 
   L_TCHAR szOverlayFileName[_MAX_PATH]; 
   FILEINFO FileInfo; 
   L_INT nRet; 
 
   ZeroMemory(&FileInfo, sizeof(FILEINFO)); 
   FileInfo.uStructSize = sizeof(FILEINFO); 
 
   // show overlay information 
   wsprintf(szBuffer, TEXT("File: %s\nPageNumber: %d\nInfo: %d"), 
      pOverlayCallbackData->pszFilename, 
      pOverlayCallbackData->nPageNumber, 
      pOverlayCallbackData->bInfo); 
   MessageBox(NULL, szBuffer, TEXT("Overlay Callback"), 0); 
 
   // construct the overlay file name (assume its c:\temp\overlay_#.tmp where # is the page number) 
   wsprintf(szOverlayFileName, MAKE_IMAGE_PATH(TEXT("Temp\\overlay_%d.tmp")), pOverlayCallbackData->nPageNumber); 
 
   if(pOverlayCallbackData->bInfo) 
   { 
      // info, we only need to fill in the nInfoXXX members of the structure 
      ZeroMemory(&FileInfo, sizeof(FILEINFO)); 
      FileInfo.uStructSize = sizeof(FILEINFO); 
      nRet = L_FileInfo(szOverlayFileName, &FileInfo, sizeof(FILEINFO), 0, NULL); 
 
      if(nRet == SUCCESS) 
      { 
         pOverlayCallbackData->nInfoWidth = FileInfo.Width; 
         pOverlayCallbackData->nInfoHeight = FileInfo.Height; 
         pOverlayCallbackData->nInfoXResolution = FileInfo.XResolution; 
         pOverlayCallbackData->nInfoYResolution = FileInfo.YResolution; 
      } 
   } 
   else 
   { 
      // we need to load the overlay bitmap into the pLoadBitmap member 
      nRet = L_LoadBitmap( 
         szOverlayFileName, 
         pOverlayCallbackData->pLoadBitmap, 
         sizeof(BITMAPHANDLE), 
         0, 
         ORDER_BGRORGRAY, 
         NULL, 
         NULL); 
   } 
 
   return nRet; 
} 
L_INT OverlayCallbackExample() 
{ 
   L_TCHAR* pszPtokaFileName = MAKE_IMAGE_PATH(TEXT("SUPPLEMENT_ON_CHECK.tmp")); 
   L_TCHAR* pszTiffFileName = MAKE_IMAGE_PATH(TEXT("test.tif")); 
   L_INT nRet; 
   OVERLAYCALLBACK pfnOldCallback; 
   L_VOID* pOldUserData; 
   L_UINT uOldFlags; 
   BITMAPHANDLE Bitmap; 
 
   ZeroMemory(&Bitmap, sizeof(BITMAPHANDLE)); 
   Bitmap.uStructSize = sizeof(BITMAPHANDLE); 
   nRet = SUCCESS; 
 
   // set the overlay callback 
 
   // first, save the old overlay callback 
   nRet = L_GetOverlayCallback(&pfnOldCallback, &pOldUserData, &uOldFlags); 
   if(nRet == SUCCESS) 
   { 
      // set the new one 
      nRet = L_SetOverlayCallback(MyOverlayCallback, NULL, OVERLAY_CALLLOAD); 
      if(nRet == SUCCESS) 
      { 
 
         // load the PTOKA file from memory 
         nRet = L_LoadBitmap(pszPtokaFileName, &Bitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGRORGRAY, NULL, NULL); 
 
         // stop the overlay by resetting the old callback. 
         nRet = L_SetOverlayCallback(pfnOldCallback, pOldUserData, uOldFlags); 
      } 
   } 
 
   // save the bitmap as TIFF 
   nRet = L_SaveBitmap(pszTiffFileName, &Bitmap, FILE_TIF, 1, 0, NULL); 
 
   // free the bitmap 
   if(Bitmap.Flags.Allocated) 
      L_FreeBitmap(&Bitmap); 
 
   return nRet; 
}