1 files changed, 139 insertions, 0 deletions
diff --git a/share/extensions/barcode/Rm4scc.py b/share/extensions/barcode/Rm4scc.py
new file mode 100644
index 0000000..b4d52ba
--- /dev/null
+++ b/share/extensions/barcode/Rm4scc.py
@@ -0,0 +1,139 @@
+# 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
+
+charmap = {
+    "(": "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):
+    """Provice a Rm4scc barcode generator"""
+
+    default_height = 18
+
+    def encode(self, text):
+        result = ""
+
+        text = text.upper()
+        text.replace("(", "")
+        text.replace(")", "")
+
+        text = "(" + text + Rm4scc.checksum(text) + ")"
+
+        i = 0
+        for char in text:
+            if char in charmap:
+                result = result + charmap[char]
+                i += 1
+
+        return result
+
+    @staticmethod
+    def checksum(text):
+        """given a string of data, return the check character"""
+        total_lower = 0
+        total_upper = 0
+        for char in text:
+            if char in charmap:
+                bars = charmap[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