1 files changed, 136 insertions, 0 deletions
diff --git a/share/extensions/barcode/Rm4scc.py b/share/extensions/barcode/Rm4scc.py
new file mode 100644
index 0000000..5687f63
--- /dev/null
+++ b/share/extensions/barcode/Rm4scc.py
@@ -0,0 +1,136 @@
+# coding=utf-8
+#
+# 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 char in map:
+                result = result + map[char]
+                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 char in map:
+                bars = map[char][0:8:2]
+                lower = 0
+                upper = 0
+
+                if int(bars[0]) & 1:
+                    lower += 4
+                if int(bars[1]) & 1:
+                    lower += 2
+                if int(bars[2]) & 1:
+                    lower += 1
+                if int(bars[0]) & 2:
+                    upper += 4
+                if int(bars[1]) & 2:
+                    upper += 2
+                if int(bars[2]) & 2:
+                    upper += 1
+            total_lower += lower % 6
+            total_upper += upper % 6
+
+        total_lower = total_upper % 6
+        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