Rm4scc.py revision ad9933c3bdd809813acc78673fcc580cd326bcd6
#
# 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 02110-1301, USA.
#
"""
Python barcode renderer for RM4CC barcodes. Designed for use with Inkscape.
"""
from Base import Barcode
map = {
'(' : '25',
')' : '3',
'0' : '05053535',
'1' : '05152535',
'2' : '05153525',
'3' : '15052535',
'4' : '15053525',
'5' : '15152525',
'6' : '05251535',
'7' : '05350535',
'8' : '05351525',
'9' : '15250535',
'A' : '15251525',
'B' : '15350525',
'C' : '05253515',
'D' : '05352515',
'E' : '05353505',
'F' : '15252515',
'G' : '15253505',
'H' : '15352505',
'I' : '25051535',
'J' : '25150535',
'K' : '25151525',
'L' : '35050535',
'M' : '35051525',
'N' : '35150525',
'O' : '25053525',
'P' : '25152515',
'Q' : '25153505',
'R' : '35052515',
'S' : '35053505',
'T' : '35152505',
'U' : '25251515',
'V' : '25350515',
'W' : '25351505',
'X' : '35250515',
'Y' : '35251505',
'Z' : '35350505',
}
check = ['ZUVWXY','501234','B6789A','HCDEFG','NIJKLM','TOPQRS']
(BAR_TRACK, BAR_DOWN, BAR_UP, BAR_FULL, BAR_NONE, WHITE_SPACE) = range(6)
class Rm4scc(Barcode):
default_height = 18
def encode(self, text):
result = ''
text = text.upper()
text.replace('(', '')
text.replace(')', '')
text = '(' + text + self.checksum(text) + ')'
i = 0
for char in text:
if map.has_key(char):
result = result + map[char]
i = i + 1
return result;
# given a string of data, return the check character
def checksum(self, text):
total_lower = 0
total_upper = 0
for char in text:
if map.has_key(char):
bars = map[char][0:8:2]
lower = 0
upper = 0
if int(bars[0]) & 1:
lower = lower + 4
if int(bars[1]) & 1:
lower = lower + 2
if int(bars[2]) & 1:
lower = lower + 1
if int(bars[0]) & 2:
upper = upper + 4
if int(bars[1]) & 2:
upper = upper + 2
if int(bars[2]) & 2:
upper = upper + 1
total_lower = total_lower + (lower % 6)
total_upper = total_upper + (upper % 6)
total_lower = total_upper % 6
total_upper = total_upper % 6
checkchar = check[total_upper][total_lower]
return checkchar
def get_style(self, index):
"""Royal Mail Barcodes use a completely different style"""
result = { 'width' : 2, 'write' : True, 'top' : 0 }
if index == BAR_TRACK: # Track Bar
result['top'] = 6
result['height'] = 5
elif index == BAR_DOWN: # Decender Bar
result['top'] = 6
result['height'] = 11
elif index == BAR_UP: # Accender Bar
result['height'] = 11
elif index == BAR_FULL: # Full Bar
result['height'] = 17
elif index == WHITE_SPACE: # White Space
result['write'] = False
return result