pdftron::Filters::FilterReader Class Reference

FilterReader is a utility class providing a convenient way to read data from an input filter (using Filter directly is not very intuitive). More...

#include <FilterReader.h>

List of all members.

Public Member Functions
	FilterReader ()
	FilterReader (Filter &filter)
	~FilterReader ()
int	Get ()
	Returns: - the next character from the stream or EOF (-1) if the end of file is reached.
int	Peek ()
	Returns: - the next character without extracting it from the stream or or EOF (-1) if the end of file is reached.
ULong	Read (UChar *buf, ULong buf_size)
	Returns: - returns the number of bytes actually read and stored in buffer (buf), which may be less than buf_size if the end of the file is encountered before reaching count.
void	AttachFilter (Filter &filter)
	Attaches a filter to the this FilterReader.
Filter	GetAttachedFilter ()
	Returns: - The attached Filter or a NULL filter if no filter is attached.
void	Seek (long offset, Filter::ReferencePos origin)
	Sets the position within the current stream.
ULong	Tell ()
	Reports the current read position in the stream relative to the stream origin.
ULong	Count ()
	Returns: - the number of bytes consumed since opening the filter or since the last Seek operation.
void	Flush ()
	Forces any data remaining in the buffer to be written to input or output filter.
void	FlushAll ()
	Forces any data remaining in the filter chain to the source or destination.

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Detailed Description

FilterReader is a utility class providing a convenient way to read data from an input filter (using Filter directly is not very intuitive).

For example:

 StdFile file("my_stream.txt", StdFile::e_read_mode);
 FilterReader reader(file);
 while (reader.Read(...)) ...

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Constructor & Destructor Documentation

pdftron::Filters::FilterReader::FilterReader

(

)

pdftron::Filters::FilterReader::FilterReader

(

Filter &

filter

)

pdftron::Filters::FilterReader::~FilterReader

(

)

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Member Function Documentation

int pdftron::Filters::FilterReader::Get

(

)

Returns:

- the next character from the stream or EOF (-1) if the end of file is reached.

int pdftron::Filters::FilterReader::Peek

(

)

Returns:

- the next character without extracting it from the stream or or EOF (-1) if the end of file is reached.

ULong pdftron::Filters::FilterReader::Read	(	UChar *	buf,
		ULong	buf_size
	)

Returns:

- returns the number of bytes actually read and stored in buffer (buf), which may be less than buf_size if the end of the file is encountered before reaching count.

void pdftron::Filters::FilterReader::AttachFilter

(

Filter &

filter

)

Attaches a filter to the this FilterReader.

Filter pdftron::Filters::FilterReader::GetAttachedFilter

(

)

Returns:

- The attached Filter or a NULL filter if no filter is attached.

void pdftron::Filters::FilterReader::Seek	(	long	offset,
		Filter::ReferencePos	origin
	)

Sets the position within the current stream.

Parameters:

	offset	- A byte offset relative to origin. If offset is negative, the new position will precede the position specified by origin by the number of bytes specified by offset. If offset is zero, the new position will be the position specified by origin. If offset is positive, the new position will follow the position specified by origin by the number of bytes specified by offset.
	origin	- A value of type ReferencePos indicating the reference point used to obtain the new position

Note:

- After each Seek() operation the number of consumed bytes (i.e. Count()) is set to 0.

Exceptions:

-

throws an exception if the method is not implemented in the associated filter.

ULong pdftron::Filters::FilterReader::Tell

(

)

Reports the current read position in the stream relative to the stream origin.

Returns:

- The current position in the stream

Exceptions:

-

throws an exception if the method is not implemented in the associated filter.

ULong pdftron::Filters::FilterReader::Count

(

)

Returns:

- the number of bytes consumed since opening the filter or since the last Seek operation.

void pdftron::Filters::FilterReader::Flush

(

)

Forces any data remaining in the buffer to be written to input or output filter.

void pdftron::Filters::FilterReader::FlushAll

(

)

Forces any data remaining in the filter chain to the source or destination.

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© 2002-2008 PDFTron Systems Inc.