NAME

PDF::Builder::Basic::PDF::Filter - Abstract superclass for PDF stream filters

SYNOPSIS

    $f = PDF::Builder::Basic::PDF::Filter->new();
    $str = $f->outfilt($str, 1);
    print OUTFILE $str;

    while (read(INFILE, $dat, 4096))
    { $store .= $f->infilt($dat, 0); }
    $store .= $f->infilt("", 1);

DESCRIPTION

A Filter object contains state information for the process of outputting and inputting data through the filter. The precise state information stored is up to the particular filter and may range from nothing to whole objects created and destroyed.

Each filter stores different state information for input and output and thus may handle one input filtering process and one output filtering process at the same time.

METHODS

PDF::Builder::Basic::PDF::Filter->new()

Creates a new filter object with empty state information ready for processing data both input and output.

$dat = $f->infilt($str, $isend)

Filters from output to input the data. Notice that $isend == 0 implies that there is more data to come and so following it $f may contain state information (usually due to the break-off point of $str not being tidy). Subsequent calls will incorporate this stored state information.

$isend == 1 implies that there is no more data to follow. The final state of $f will be that the state information is empty. Error messages are most likely to occur here since if there is required state information to be stored following this data, then that would imply an error in the data.

$str = $f->outfilt($dat, $isend)

Filter stored data ready for output. Parallels infilt.

Up (Parents)

Master Index
PDF::Builder -- Facilitates the creation and modification of PDF files
PDF::Builder::Basic::PDF -- Various utilities and support routines

Siblings

PDF::Builder::Basic::PDF::Array -- Corresponds to a PDF array. Inherits from PDF::Builder::Basic::PDF::Objind
PDF::Builder::Basic::PDF::Bool -- A special form of PDF::Builder::Basic::PDF::String which holds the strings true or false
PDF::Builder::Basic::PDF::Dict -- PDF Dictionaries and Streams. Inherits from PDF::Builder::Basic::PDF::Objind
PDF::Builder::Basic::PDF::File -- Holds the trailers and cross-reference tables for a PDF file
PDF::Builder::Basic::PDF::Literal -- Literal PDF Object. Inherits from PDF::Builder::Basic::PDF::Objind
PDF::Builder::Basic::PDF::Name -- Inherits from PDF::Builder::Basic::PDF::String and stores PDF names (things beginning with /)
PDF::Builder::Basic::PDF::Null -- PDF Null type object. This is a subclass of PDF::Builder::Basic::PDF::Objind and cannot be subclassed.
PDF::Builder::Basic::PDF::Number -- Numbers in PDF. Inherits from PDF::Builder::Basic::PDF::String
PDF::Builder::Basic::PDF::Objind -- PDF indirect object reference. Also acts as an abstract superclass for all elements in a PDF file.
PDF::Builder::Basic::PDF::Page -- Represents a PDF page, inherits from PDF::Builder::Basic::PDF::Pages
PDF::Builder::Basic::PDF::Pages -- a PDF pages hierarchical element. Inherits from PDF::Builder::Basic::PDF::Dict
PDF::Builder::Basic::PDF::String -- PDF String type objects and superclass for simple objects that are basically stringlike (Number, Name, etc.)
PDF::Builder::Basic::PDF::Utils -- Utility functions for PDF library

Down (Children)

PDF::Builder::Basic::PDF::Filter::ASCII85Decode -- compress and uncompress stream filters for ASCII-85
PDF::Builder::Basic::PDF::Filter::ASCIIHexDecode -- compress and uncompress stream filters for ASCII-Hex
PDF::Builder::Basic::PDF::Filter::FlateDecode -- compress and uncompress stream filters for Flate
PDF::Builder::Basic::PDF::Filter::LZWDecode -- compress and uncompress stream filters for Lempel-Ziv-Welch
PDF::Builder::Basic::PDF::Filter::RunLengthDecode -- compress and uncompress stream filters for Run-Length

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