share/extensions/Barcode/UPCE.py

   1 '''
   2 Copyright (C) 2007 Martin Owens
   3
   4 Thanks to Lineaire Chez of Inkbar ( www.inkbar.lineaire.net )
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 '''
  20
  21 import EAN13
  22 from EAN13 import mapLeftFaimly, guardBar, centerBar
  23 import sys
  24
  25 mapFamily  = [ '000111','001011','001101','001110','010011','011001','011100','010101','010110','011010' ]
  26
  27 class Object(EAN13.Object):
  28         def encode(self, number):
  29                 result = ''
  30
  31                 l = len(number)
  32
  33                 if (l != 6 and l != 7  and l != 11 and l != 12) or not number.isdigit():
  34                         sys.stderr.write("Can not encode '" + number + "' into UPC-E Barcode, Size must be 6 numbers only, and 1 check digit (optional)\nOr a convertable 11 digit UPC-A number with 1 check digit (also optional).\n")
  35                         return
  36
  37                 echeck = None
  38                 if l==7 or l==12:
  39                         echeck = number[-1]
  40                         number = number[:-1]
  41                         sys.stderr.write("CHECKSUM FOUND!")
  42                         l -= 1
  43
  44                 if l==6:
  45                         number = self.ConvertEtoA(number)
  46
  47                 if not echeck:
  48                         echeck = self.getChecksum(number)
  49                 else:
  50                         if not self.verifyChecksum(number + echeck):
  51                                 sys.stderr.write("UPC-E Checksum not correct for this barcode, omit last character to generate new checksum.\n")
  52                                 return
  53
  54                 number = self.ConvertAtoE(number)
  55                 if not number:
  56                         sys.stderr.write("UPC-A code could not be converted into a UPC-E barcode, please follow the UPC guide or enter a 6 digit UPC-E number..\n")
  57                         return
  58
  59                 number = number
  60
  61                 result = result + guardBar
  62                 # The check digit isn't stored as bars but as a mirroring system. :-(
  63                 family = mapFamily[int(echeck)]
  64
  65                 i = 0
  66                 for i in range(0,6):
  67                         result += mapLeftFaimly[int(family[i])-1][int(number[i])]
  68
  69                 result = result + centerBar + '2';
  70
  71                 self.label    = '0  ' + number[:6] + '  ' + echeck
  72                 self.inclabel = self.label
  73                 return result;
  74
  75         def fontSize(self):
  76                 return '10'
  77
  78         def ConvertAtoE(self, number):
  79                 # Converting UPC-A to UPC-E
  80
  81                 # All UPC-E Numbers use number system 0
  82                 if number[0] != '0' or len(number)!=11:
  83                         # If not then the code is invalid
  84                         return None
  85
  86                 # Most of the conversions deal
  87                 # with the specific code parts
  88                 manufacturer = number[1:6]
  89                 product = number[6:11]
  90
  91                 # There are 4 cases to convert:
  92                 if manufacturer[2:] == '000' or manufacturer[2:] == '100' or manufacturer[2:] == '200':
  93                         # Maxium number product code digits can be encoded
  94                         if product[:2]=='00':
  95                                 return manufacturer[:2] + product[2:] + manufacturer[2]
  96                 elif manufacturer[3:5] == '00':
  97                         # Now only 2 product code digits can be used
  98                         if product[:3]=='000':
  99                                 return manufacturer[:3] + product[3:] + '3'
 100                 elif manufacturer[4] == '0':
 101                         # With even more manufacturer code we have less room for product code
 102                         if product[:4]=='0000':
 103                                 return manufacturer[0:4] + product[4] + '4'
 104                 elif product[:4]=='0000' and int(product[4]) > 4:
 105                         # The last recorse is to try and squeeze it in the last 5 numbers
 106                         # so long as the product is 00005-00009 so as not to conflict with
 107                         # the 0-4 used above.
 108                         return manufacturer + product[4]
 109                 else:
 110                         # Invalid UPC-A Numbe
 111                         return None
 112
 113         def ConvertEtoA(self, number):
 114                 # Convert UPC-E to UPC-A
 115
 116                 # It's more likly to convert this without fault
 117                 # But we still must be mindful of the 4 conversions
 118                 if len(number)!=6:
 119                         return None
 120
 121                 if number[5]=='0' or number[5]=='1' or number[5]=='2':
 122                         return '0' + number[:2] + number[5] + '0000' + number[2:5]
 123                 elif number[5]=='3':
 124                         return '0' + number[:3] + '00000' + number[3:5]
 125                 elif number[5]=='4':
 126                         return '0' + number[:4] + '00000' + number[4]
 127                 else:
 128                         return '0' + number[:5] + '0000' + number[5]
 129