GD::Barcode - Create barcode image with GD

GD-Barcode documentation Contained in the GD-Barcode distribution.

Index

Code Index:

NAME

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GD::Barcode - Create barcode image with GD

SYNOPSIS

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ex. CGI

  use GD::Barcode::UPCE;
  binmode(STDOUT);
  print "Content-Type: image/png\n\n";
  print GD::Barcode->new('EAN13', '123456789012')->plot->png;

with Error Check

  my $oGdBar = GD::Barcode->new('EAN13', '12345678901');
  die $GD::Barcode::errStr unless($oGdBar);     #Invalid Length
  $oGdBar->plot->png;

DESCRIPTION

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GD::Barcode is a subclass of GD and allows you to create barcode image with GD. This module based on "Generate Barcode Ver 1.02 By Shisei Hanai 97/08/22".

From 1.14, you can use this module even if no GD (except plot method).

new

$oGdBar = GD::Barcode::UPCE->new($sType, $sTxt);

Constructor. Creates a GD::Barcode::$sType object for $sTxt.

plot()

$oGd = $oGdBar->plot([Height => $iHeight, NoText => 0 | 1]);

creates GD object with barcode image for the $sTxt specified at new method. $iHeight is height of the image. If NoText is 1, the image has no text image of $sTxt.

 ex.
  my $oGdB = GD::Barcode->new('EAN13', '123456789012');
  my $oGD = $oGdB->plot(NoText=>1, Height => 20);
  # $sGD is a GD image with Height=>20 pixels, with no text.

barcode()

$sPtn = $oGdBar->barcode();

returns a barcode pattern in string with '1' and '0'. '1' means black, '0' means white.

 ex.
  my $oGdB = GD::Barcode->new('UPCE', '123456789012');
  my $sPtn = $oGdB->barcode();
  # $sPtn = '';

$errStr

$GD::Barcode::errStr

has error message.

$text

$oGdBar->{$text}

has barcode text based on $sTxt specified in new method.

AUTHOR

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Kawai Takanori GCD00051@nifty.ne.jp

COPYRIGHT

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The GD::Barocde module is Copyright (c) 2000 Kawai Takanori. Japan. All rights reserved.

You may distribute under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file.

SEE ALSO

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GD GD::Barcode subclasses

GD-Barcode documentation Contained in the GD-Barcode distribution. 
package GD::Barcode;
require Exporter;
use strict;
use vars qw($VERSION @ISA $errStr);
@ISA = qw(Exporter);
$VERSION=1.15;
my @aLoaded = ();
#------------------------------------------------------------------------------
# new (for GD::Barcode)
#------------------------------------------------------------------------------
sub new($$$;$) {
        my($sClass, $sType, $sTxt, $rhPrm) = @_;
        my $oThis = {};
        unless(grep(/^$sType$/, @aLoaded)) {
        eval "require 'GD/Barcode/$sType.pm';";
        if($@) {
                $errStr = "Can't load $sType : $@";
                return undef;
                }
                push(@aLoaded, $sType);
        }
        bless $oThis, "GD::Barcode::$sType";
        return undef if($errStr = $oThis->init($sTxt, $rhPrm));
        return $oThis;
}
#------------------------------------------------------------------------------
# barPtn (for GD::Barcode)
#------------------------------------------------------------------------------
sub barPtn {
    my($bar, $table) = @_;
    my($sWk, $sRes);

    $sRes = '';
    foreach $sWk (split(//, $bar)) {
                $sRes .= $table->{$sWk};
    }
    return $sRes;
}
#------------------------------------------------------------------------------
# dumpCode (for GD::Barcode) for Code39, NW7...
#------------------------------------------------------------------------------
sub dumpCode {
    my( $sCode ) = @_;
    my($sWk, $sRes, $sClr);

#Init
    $sRes = '';
    $sClr = '1';  # 1: Black, 0:White

    foreach $sWk (split(//, $sCode)) {
                $sRes .= ($sWk eq '1')? $sClr x 3 : $sClr;      #3 times or Normal
                $sClr = ($sClr eq '0')? '1': '0';
    }
    return $sRes;
}
#------------------------------------------------------------------------------
# plot (for GD::Barcode)
#------------------------------------------------------------------------------
sub plot($$$$$) {
  my($sBarcode, $iWidth, $iHeight, $fH, $iStart) = @_;
  #Create Image
  my ($gdNew, $cWhite, $cBlack);
  eval {
    $gdNew = GD::Image->new($iWidth, $iHeight);
    $cWhite = $gdNew->colorAllocate(255, 255, 255);
    $cBlack = $gdNew->colorAllocate(  0,   0,   0);

    my $iPos =$iStart;
    foreach my $cWk (split(//,$sBarcode)) {
        if($cWk eq '0') {
            $gdNew->line($iPos, 0, $iPos, $iHeight - $fH, $cWhite);
        }
        elsif ($cWk eq 'G') {
            $gdNew->line($iPos, 0, $iPos, $iHeight - 2*($fH/3), $cBlack);
        }
        else {                              #$cWk eq "1" etc.
            $gdNew->line($iPos, 0, $iPos, $iHeight - $fH, $cBlack);
        }
        $iPos++;
    }
  };
  return ($gdNew, $cBlack);
}
#------------------------------------------------------------------------------
# Text (for GD::Barcode)
#------------------------------------------------------------------------------
sub Text($) {
        my($oThis) = @_;
        return $oThis->{text};
}
1;
__END__