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Diffstat (limited to 'share/extensions/barcode/Code128.py')
| -rw-r--r-- | share/extensions/barcode/Code128.py | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/share/extensions/barcode/Code128.py b/share/extensions/barcode/Code128.py new file mode 100644 index 0000000..20876b3 --- /dev/null +++ b/share/extensions/barcode/Code128.py @@ -0,0 +1,158 @@ +# coding=utf-8 +# +# Authored by Martin Owens <doctormo@gmail.com> +# Debugged by Ralf Heinecke & Martin Siepmann 2007-09-07 +# Horst Schottky 2010-02-27 +# +# Copyright (C) 2007 Martin Owens +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA. +# +""" +Renderer for Code128/EAN128 codes. Designed for use with Inkscape. +""" + +import re + +from .Base import Barcode + +CODE_MAP = [ + '11011001100', '11001101100', '11001100110', '10010011000', '10010001100', + '10001001100', '10011001000', '10011000100', '10001100100', '11001001000', + '11001000100', '11000100100', '10110011100', '10011011100', '10011001110', + '10111001100', '10011101100', '10011100110', '11001110010', '11001011100', + '11001001110', '11011100100', '11001110100', '11101101110', '11101001100', + '11100101100', '11100100110', '11101100100', '11100110100', '11100110010', + '11011011000', '11011000110', '11000110110', '10100011000', '10001011000', + '10001000110', '10110001000', '10001101000', '10001100010', '11010001000', + '11000101000', '11000100010', '10110111000', '10110001110', '10001101110', + '10111011000', '10111000110', '10001110110', '11101110110', '11010001110', + '11000101110', '11011101000', '11011100010', '11011101110', '11101011000', + '11101000110', '11100010110', '11101101000', '11101100010', '11100011010', + '11101111010', '11001000010', '11110001010', '10100110000', '10100001100', + '10010110000', '10010000110', '10000101100', '10000100110', '10110010000', + '10110000100', '10011010000', '10011000010', '10000110100', '10000110010', + '11000010010', '11001010000', '11110111010', '11000010100', '10001111010', + '10100111100', '10010111100', '10010011110', '10111100100', '10011110100', + '10011110010', '11110100100', '11110010100', '11110010010', '11011011110', + '11011110110', '11110110110', '10101111000', '10100011110', '10001011110', + '10111101000', '10111100010', '11110101000', '11110100010', '10111011110', + '10111101110', '11101011110', '11110101110', '11010000100', '11010010000', + '11010011100', '11000111010', '11'] + + +def map_extra(data, chars): + """Maps the data into the chars""" + result = list(data) + for char in chars: + result.append(chr(char)) + result.append('FNC3') + result.append('FNC2') + result.append('SHIFT') + return result + + +# The map_extra method is used to slim down the amount +# of pre code and instead we generate the lists +CHAR_AB = list(" !\"#$%&\'()*+,-./0123456789:;<=>?@" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_") +CHAR_A = map_extra(CHAR_AB, range(0, 31)) # Offset 64 +CHAR_B = map_extra(CHAR_AB, range(96, 125)) # Offset -32 + + +class Code128(Barcode): + """Main barcode object, generates the encoding bits here""" + + def encode(self, text): + blocks = [] + block = '' + + # Split up into sections of numbers, or characters + # This makes sure that all the characters are encoded + # In the best way possible for Code128 + for datum in re.findall(r'(?:(?:\d\d){2,})|(?:^\d\d)|.', text): + if len(datum) == 1: + block = block + datum + else: + if block: + blocks.append(self.best_block(block)) + block = '' + blocks.append(['C', datum]) + + if block: + blocks.append(self.best_block(block)) + block = '' + + return self.encode_blocks(blocks) + + def best_block(self, block): + """If this has lower case then select B over A""" + if block.upper() == block: + return ['A', block] + return ['B', block] + + def encode_blocks(self, blocks): + """Encode the given blocks into A, B or C codes""" + encode = '' + total = 0 + pos = 0 + + for block in blocks: + b_set = block[0] + datum = block[1] + + # POS : 0, 1 + # A : 101, 103 + # B : 100, 104 + # C : 99, 105 + num = 0 + if b_set == 'A': + num = 103 + elif b_set == 'B': + num = 104 + elif b_set == 'C': + num = 105 + + i = pos + if pos: + num = 204 - num + else: + i = 1 + + total = total + num * i + encode = encode + CODE_MAP[num] + pos += 1 + + if b_set == 'A' or b_set == 'B': + chars = CHAR_B + if b_set == 'A': + chars = CHAR_A + + for char in datum: + total = total + (chars.index(char) * pos) + encode = encode + CODE_MAP[chars.index(char)] + pos += 1 + else: + for char in (datum[i:i + 2] for i in range(0, len(datum), 2)): + total = total + (int(char) * pos) + encode = encode + CODE_MAP[int(char)] + pos += 1 + + checksum = total % 103 + encode = encode + CODE_MAP[checksum] + encode = encode + CODE_MAP[106] + encode = encode + CODE_MAP[107] + + return encode |