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LFile::LoadFileCallBack

Summary

Handles the output image data that the LFile::LoadFile function has written to a buffer.

Syntax

#include "ltwrappr.h"

virtual L_INT LFile::LoadFileCallBack(pFileInfo, pLBitmap, pLBuffer, uFlags, nRow, nLines)

Parameters

pFILEINFO pFileInfo

Pointer to the FILEINFO structure that contains image information.

LBitmapBase * pLBitmap

Pointer to the bitmap object referencing the bitmap that contains the image information.

LBuffer * pLBuffer

Pointer to a buffer object containing one or more lines of output image data that the calling function has already processed (read or decompressed).

L_UINT uFlags

Flags that describe whether this is the first or last call of the callback, and whether the buffer contains first or last row of image data. The following are possible flags:

Constant	Meaning
FILEREAD_FIRSTPASS	[0x0001] This is the first pass through a progressive JPEG or CMP file.
FILEREAD_LASTPASS	[0x0002] This is the last pass through a progressive JPEG or CMP file.
FILEREAD_FIRSTROW	[0x0004] The first row of the buffer is the first row of the bitmap.
FILEREAD_LASTROW	[0x0008] The last row of the buffer is the last row of the bitmap.
FILEREAD_COMPRESSED	[0x0010] The data in the buffer is 1-bit compressed data, which you can handle as explained in Speeding Up 1-Bit Documents.
FILEREAD_CLIPVERT	[0x0020] Internal flag.
FILEREAD_CLIPHORZ	[0x0040] Internal flag.
FILEREAD_UPDATELUT	[0x0080] Internal flag.

L_INT nRow

The current bitmap row number of the first line in the buffer.

L_INT nLines

The number of lines in the pLBuffer buffer object.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

Override this function to handle the output image data that the LFile::LoadFile function has written to a buffer.

In some cases, The pLBuffer buffer object contains data that your callback function must output in order for the calling function to accomplish anything. In other cases, where the callback is optional, the callback gets a copy of the data, and the callback's output is in addition to the calling function's output. Refer to the description of the LFile::LoadFile function to see how it uses the callback. The FILEINFO structure that gets passed to this function does not contain the total number of pages. To get the total number of pages, you should call LFile::GetInfo and set the FILEINFO_TOTALPAGES flag.

Required DLLs and Libraries

LTFIL
File format DLLs
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.