oca-ocb-core/odoo-bringout-oca-ocb-base/odoo/tools/barcode.py
Ernad Husremovic 991d2234ca 19.0 vanilla
2025-10-03 18:07:25 +02:00

93 lines
3.8 KiB
Python

# Part of Odoo. See LICENSE file for full copyright and licensing details.
import functools
import re
from threading import RLock
__all__ = ['check_barcode_encoding', 'createBarcodeDrawing', 'get_barcode_font']
_barcode_init_lock = RLock()
# A lock occurs when the user wants to print a report having multiple barcode while the server is
# started in threaded-mode. The reason is that reportlab has to build a cache of the T1 fonts
# before rendering a barcode (done in a C extension) and this part is not thread safe.
# This cached functions allows to lazily initialize the T1 fonts cache need for rendering of
# barcodes in a thread-safe way.
@functools.lru_cache(1)
def _init_barcode():
with _barcode_init_lock:
try:
from reportlab.graphics import barcode # noqa: PLC0415
from reportlab.pdfbase.pdfmetrics import TypeFace, getFont # noqa: PLC0415
font_name = 'Courier'
available = TypeFace(font_name).findT1File()
if not available:
substitution_font = 'NimbusMonoPS-Regular'
fnt = getFont(substitution_font)
if fnt:
font_name = substitution_font
fnt.ascent = 629
fnt.descent = -157
barcode.createBarcodeDrawing('Code128', value='foo', format='png', width=100, height=100, humanReadable=1, fontName=font_name).asString('png')
except ImportError:
raise
except Exception: # noqa: BLE001
font_name = 'Courier'
return barcode, font_name
def createBarcodeDrawing(codeName: str, **options):
barcode, _font = _init_barcode()
return barcode.createBarcodeDrawing(codeName, **options)
def get_barcode_font():
"""Get the barcode font for rendering."""
_barcode, font = _init_barcode()
return font
def get_barcode_check_digit(numeric_barcode: str) -> int:
""" Computes and returns the barcode check digit. The used algorithm
follows the GTIN specifications and can be used by all compatible
barcode nomenclature, like as EAN-8, EAN-12 (UPC-A) or EAN-13.
https://www.gs1.org/sites/default/files/docs/barcodes/GS1_General_Specifications.pdf
https://www.gs1.org/services/how-calculate-check-digit-manually
:param numeric_barcode: the barcode to verify/recompute the check digit
:return: the number corresponding to the right check digit
"""
# Multiply value of each position by
# N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 N12 N13 N14 N15 N16 N17 N18
# x3 X1 x3 x1 x3 x1 x3 x1 x3 x1 x3 x1 x3 x1 x3 x1 x3 CHECKSUM
oddsum = evensum = 0
code = numeric_barcode[-2::-1] # Remove the check digit and reverse the barcode.
# The CHECKSUM digit is removed because it will be recomputed and it must not interfer with
# the computation. Also, the barcode is inverted, so the barcode length doesn't matter.
# Otherwise, the digits' group (even or odd) could be different according to the barcode length.
for i, digit in enumerate(code):
if i % 2 == 0:
evensum += int(digit)
else:
oddsum += int(digit)
total = evensum * 3 + oddsum
return (10 - total % 10) % 10
def check_barcode_encoding(barcode: str, encoding: str) -> bool:
""" Checks if the given barcode is correctly encoded.
:return: True if the barcode string is encoded with the provided encoding.
"""
encoding = encoding.lower()
if encoding == "any":
return True
barcode_sizes = {
'ean8': 8,
'ean13': 13,
'gtin14': 14,
'upca': 12,
'sscc': 18,
}
barcode_size = barcode_sizes[encoding]
return (encoding != 'ean13' or barcode[0] != '0') \
and len(barcode) == barcode_size \
and re.match(r"^\d+$", barcode) \
and get_barcode_check_digit(barcode) == int(barcode[-1])