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diff --git a/share/extensions/barcode/Base.py b/share/extensions/barcode/Base.py
new file mode 100644
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+++ b/share/extensions/barcode/Base.py
@@ -0,0 +1,166 @@
+# coding=utf-8
+#
+# Copyright (C) 2010 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.
+#
+"""
+Base module for rendering barcodes for Inkscape.
+"""
+
+import itertools
+import sys
+
+from inkex import Group, TextElement, Rectangle
+
+(TEXT_POS_BOTTOM, TEXT_POS_TOP) = range(2)
+(WHITE_BAR, BLACK_BAR, TALL_BAR) = range(3)
+TEXT_TEMPLATE = 'font-size:%dpx;text-align:center;text-anchor:middle;'
+
+try:
+    from typing import Optional
+except ImportError:
+    pass
+
+class Barcode(object):
+    """Provide a base class for all barcode renderers"""
+    default_height = 30
+    font_size = 9
+    name = None # type: Optional[str]
+
+    def error(self, text, msg):
+        """Cause an error to be reported"""
+        sys.stderr.write(
+                "Error encoding '{}' as {} barcode: {}\n".format(text, self.name, msg))
+        return "ERROR"
+
+    def encode(self, text):
+        """
+        Replace this with the encoding function, it should return
+        a string of ones and zeros
+        """
+        raise NotImplementedError("You need to write an encode() function.")
+
+    def __init__(self, param):
+        param = param or {}
+        self.document = param.get('document', None)
+        self.known_ids = []
+        self._extra = []
+
+        self.pos_x = int(param.get('x', 0))
+        self.pos_y = int(param.get('y', 0))
+        self.text = param.get('text', None)
+        self.scale = param.get('scale', 1)
+        self.height = param.get('height', self.default_height)
+        self.pos_text = param.get('text_pos', TEXT_POS_BOTTOM)
+
+        if self.document:
+            self.known_ids = list(self.document.xpath('//@id'))
+
+        if not self.text:
+            raise ValueError("No string specified for barcode.")
+
+    def get_id(self, name='element'):
+        """Get the next useful id (and claim it)"""
+        index = 0
+        while name in self.known_ids:
+            index += 1
+            name = 'barcode{:d}'.format(index)
+        self.known_ids.append(name)
+        return name
+
+    def add_extra_barcode(self, barcode, **kw):
+        """Add an extra barcode along side this one, used for ean13 extras"""
+        from . import get_barcode
+        kw['height'] = self.height
+        kw['document'] = self.document
+        kw['scale'] = None
+        self._extra.append(get_barcode(barcode, **kw).generate())
+
+    def generate(self):
+        """Generate the actual svg from the coding"""
+        string = self.encode(self.text)
+
+        if string == 'ERROR':
+            return
+
+        name = self.get_id('barcode')
+
+        # use an svg group element to contain the barcode
+        barcode = Group()
+        barcode.set('id', name)
+        barcode.set('style', 'fill: black;')
+
+        barcode.transform.add_translate(self.pos_x, self.pos_y)
+        if self.scale:
+            barcode.transform.add_scale(self.scale)
+
+        bar_id = 1
+        bar_offset = 0
+        tops = set()
+
+        for datum in self.graphical_array(string):
+            # Datum 0 tells us what style of bar is to come next
+            style = self.get_style(int(datum[0]))
+            # Datum 1 tells us what width in units,
+            # style tells us how wide a unit is
+            width = int(datum[1]) * int(style['width'])
+
+            if style['write']:
+                tops.add(style['top'])
+                rect = Rectangle()
+                rect.set('x', str(bar_offset))
+                rect.set('y', str(style['top']))
+                if self.pos_text == TEXT_POS_TOP:
+                    rect.set('y', str(style['top'] + self.font_size))
+                rect.set('id', "{}_bar{:d}".format(name, bar_id))
+                rect.set('width', str(width))
+                rect.set('height', str(style['height']))
+                barcode.append(rect)
+            bar_offset += width
+            bar_id += 1
+
+        for extra in self._extra:
+            if extra is not None:
+                barcode.append(extra)
+
+        bar_width = bar_offset
+        # Add text at the bottom of the barcode
+        text = TextElement()
+        text.set('x', str(int(bar_width / 2)))
+        text.set('y', str(min(tops) + self.font_size - 1))
+        if self.pos_text == TEXT_POS_BOTTOM:
+            text.set('y', str(self.height + max(tops) + self.font_size))
+        text.set('style', TEXT_TEMPLATE % self.font_size)
+        text.set('xml:space', 'preserve')
+        text.set('id', '{}_text'.format(name))
+        text.text = str(self.text)
+        barcode.append(text)
+        return barcode
+
+    def graphical_array(self, code):
+        """Converts black and white markets into a space array"""
+        return [(x, len(list(y))) for x, y in itertools.groupby(code)]
+
+    def get_style(self, index):
+        """Returns the styles that should be applied to each bar"""
+        result = {'width': 1, 'top': 0, 'write': True}
+        if index == BLACK_BAR:
+            result['height'] = int(self.height)
+        if index == TALL_BAR:
+            result['height'] = int(self.height) + int(self.font_size / 2)
+        if index == WHITE_BAR:
+            result['write'] = False
+        return result