1 files changed, 116 insertions, 0 deletions
diff --git a/share/extensions/barcode/Code93.py b/share/extensions/barcode/Code93.py
new file mode 100644
index 0000000..e7af072
--- /dev/null
+++ b/share/extensions/barcode/Code93.py
@@ -0,0 +1,116 @@
+# 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, USA.
+#
+"""
+Python barcode renderer for Code93 barcodes. Designed for use with Inkscape.
+"""
+
+from .Base import Barcode
+
+PALLET = list('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%')
+PALLET.append('($)')
+PALLET.append('(/)')
+PALLET.append('(+)')
+PALLET.append('(%)')
+PALLET.append('MARKER')
+
+MAP = dict((PALLET[i], i) for i in range(len(PALLET)))
+
+
+def get_map(array):
+    """Extended ENCODE maps for full ASCII Code93"""
+    result = {}
+    pos = 10
+    for char in array:
+        result[chr(char)] = PALLET[pos]
+        pos += 1
+    return result
+
+
+# MapA is eclectic, but B, C, D are all ASCII ranges
+MAP_A = get_map([27, 28, 29, 30, 31, 59, 60, 61, 62, 63, 91, 92, 93, 94, 95,
+                 123, 124, 125, 126, 127, 0, 64, 96, 127, 127, 127])  # %
+MAP_B = get_map(range(1, 26))  # $
+MAP_C = get_map(range(33, 58))  # /
+MAP_D = get_map(range(97, 122))  # +
+
+ENCODE = [
+    '100010100', '101001000', '101000100', '101000010', '100101000',
+    '100100100', '100100010', '101010000', '100010010', '100001010',
+    '110101000', '110100100', '110100010', '110010100', '110010010',
+    '110001010', '101101000', '101100100', '101100010', '100110100',
+    '100011010', '101011000', '101001100', '101000110', '100101100',
+    '100010110', '110110100', '110110010', '110101100', '110100110',
+    '110010110', '110011010', '101101100', '101100110', '100110110',
+    '100111010', '100101110', '111010100', '111010010', '111001010',
+    '101101110', '101110110', '110101110', '100100110', '111011010',
+    '111010110', '100110010', '101011110', ''
+]
+
+
+class Code93(Barcode):
+    def encode(self, text):
+        # start marker
+        bits = ENCODE[MAP.get('MARKER', -1)]
+
+        # Extend to ASCII charset ( return Array )
+        text = self.encode_ascii(text)
+
+        # Calculate the checksums
+        text.append(self.checksum(text, 20))  # C
+        text.append(self.checksum(text, 15))  # K
+
+        # Now convert text into the ENCODE bits (black and white stripes)
+        for char in text:
+            bits = bits + ENCODE[MAP.get(char, -1)]
+
+        # end marker and termination bar
+        return bits + ENCODE[MAP.get('MARKER', -1)] + '1'
+
+    def checksum(self, text, mod):
+        """Generate a code 93 checksum"""
+        weight = len(text) % mod
+        check = 0
+        for char in text:
+            check = check + (MAP[char] * weight)
+            # Reset the weight is required
+            weight -= 1
+            if weight == 0:
+                weight = mod
+
+        return PALLET[check % 47]
+
+    # Some characters need re-ENCODE into the code93 specification
+    def encode_ascii(self, text):
+        result = []
+        for char in text:
+            if char in MAP:
+                result.append(char)
+            elif char in MAP_A:
+                result.append('(%)')
+                result.append(MAP_A[char])
+            elif char in MAP_B:
+                result.append('($)')
+                result.append(MAP_B[char])
+            elif char in MAP_C:
+                result.append('(/)')
+                result.append(MAP_C[char])
+            elif char in MAP_D:
+                result.append('(+)')
+                result.append(MAP_D[char])
+        return result