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 ()
int Peek ()
size_t Read (UChar *buf, size_t buf_size)
void AttachFilter (Filter &filter)
 Attaches a filter to the this FilterReader.
Filter GetAttachedFilter ()
void Seek (ptrdiff_t offset, Filter::ReferencePos origin)
 Sets the position within the current stream.
ptrdiff_t Tell ()
 Reports the current read position in the stream relative to the stream origin.
size_t Count ()
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.


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(...)) ...

Constructor & Destructor Documentation

pdftron::Filters::FilterReader::FilterReader (  ) 

pdftron::Filters::FilterReader::FilterReader ( Filter filter  ) 

pdftron::Filters::FilterReader::~FilterReader (  ) 


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.

size_t pdftron::Filters::FilterReader::Read ( UChar buf,
size_t  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 ( ptrdiff_t  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.

ptrdiff_t 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.

size_t 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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