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import gzip
import os
import xml.dom
from typing import BinaryIO
from barcode.version import version
try:
import Image
import ImageDraw
import ImageFont
except ImportError:
try:
from PIL import Image # lint:ok
from PIL import ImageDraw
from PIL import ImageFont
except ImportError:
import logging
log = logging.getLogger("pyBarcode")
log.info("Pillow not found. Image output disabled")
Image = ImageDraw = ImageFont = None # lint:ok
def mm2px(mm, dpi=300):
return (mm * dpi) / 25.4
def pt2mm(pt):
return pt * 0.352777778
def _set_attributes(element, **attributes):
for key, value in attributes.items():
element.setAttribute(key, value)
def create_svg_object(with_doctype=False):
imp = xml.dom.getDOMImplementation()
doctype = imp.createDocumentType(
"svg",
"-//W3C//DTD SVG 1.1//EN",
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd",
)
document = imp.createDocument(None, "svg", doctype if with_doctype else None)
_set_attributes(
document.documentElement, version="1.1", xmlns="http://www.w3.org/2000/svg"
)
return document
SIZE = "{0:.3f}mm"
COMMENT = f"Autogenerated with python-barcode {version}"
PATH = os.path.dirname(os.path.abspath(__file__))
class BaseWriter:
"""Baseclass for all writers.
Initializes the basic writer options. Childclasses can add more
attributes and can set them directly or using
`self.set_options(option=value)`.
:parameters:
initialize : Function
Callback for initializing the inheriting writer.
Is called: `callback_initialize(raw_code)`
paint_module : Function
Callback for painting one barcode module.
Is called: `callback_paint_module(xpos, ypos, width, color)`
paint_text : Function
Callback for painting the text under the barcode.
Is called: `callback_paint_text(xpos, ypos)` using `self.text`
as text.
finish : Function
Callback for doing something with the completely rendered
output.
Is called: `return callback_finish()` and must return the
rendered output.
"""
def __init__(
self,
initialize=None,
paint_module=None,
paint_text=None,
finish=None,
) -> None:
self._callbacks = {
"initialize": initialize,
"paint_module": paint_module,
"paint_text": paint_text,
"finish": finish,
}
self.module_width = 10
self.module_height = 10
self.font_path = os.path.join(PATH, "fonts", "DejaVuSansMono.ttf")
self.font_size = 10
self.quiet_zone = 6.5
self.background = "white"
self.foreground = "black"
self.text = ""
self.human = "" # human readable text
self.text_distance = 5
self.text_line_distance = 1
self.center_text = True
self.guard_height_factor = 1.1
self.margin_top = 1
self.margin_bottom = 1
def calculate_size(self, modules_per_line, number_of_lines):
"""Calculates the size of the barcode in pixel.
:parameters:
modules_per_line : Integer
Number of modules in one line.
number_of_lines : Integer
Number of lines of the barcode.
:returns: Width and height of the barcode in pixel.
:rtype: Tuple
"""
width = 2 * self.quiet_zone + modules_per_line * self.module_width
height = (
self.margin_bottom + self.margin_top + self.module_height * number_of_lines
)
number_of_text_lines = len(self.text.splitlines())
if self.font_size and self.text:
height += (
pt2mm(self.font_size) / 2 * number_of_text_lines + self.text_distance
)
height += self.text_line_distance * (number_of_text_lines - 1)
return width, height
def save(self, filename, output):
"""Saves the rendered output to `filename`.
:parameters:
filename : String
Filename without extension.
output : String
The rendered output.
:returns: The full filename with extension.
:rtype: String
"""
raise NotImplementedError
def register_callback(self, action, callback):
"""Register one of the three callbacks if not given at instance
creation.
:parameters:
action : String
One of 'initialize', 'paint_module', 'paint_text', 'finish'.
callback : Function
The callback function for the given action.
"""
self._callbacks[action] = callback
def set_options(self, options):
"""Sets the given options as instance attributes (only
if they are known).
:parameters:
options : Dict
All known instance attributes and more if the childclass
has defined them before this call.
:rtype: None
"""
for key, val in options.items():
key = key.lstrip("_")
if hasattr(self, key):
setattr(self, key, val)
def packed(self, line):
"""
Pack line to list give better gfx result, otherwise in can
result in aliasing gaps
'11010111' -> [2, -1, 1, -1, 3]
This method will yield a sequence of pairs (width, height_factor).
:parameters:
line: String
A string matching the writer spec
(only contain 0 or 1 or G).
"""
line += " "
c = 1
for i in range(0, len(line) - 1):
if line[i] == line[i + 1]:
c += 1
else:
if line[i] == "1":
yield (c, 1)
elif line[i] == "G":
yield (c, self.guard_height_factor)
else:
yield (-c, self.guard_height_factor)
c = 1
def render(self, code):
"""Renders the barcode to whatever the inheriting writer provides,
using the registered callbacks.
:parameters:
code : List
List of strings matching the writer spec
(only contain 0 or 1 or G).
"""
if self._callbacks["initialize"] is not None:
self._callbacks["initialize"](code)
ypos = self.margin_top
base_height = self.module_height
for cc, line in enumerate(code):
# Left quiet zone is x startposition
xpos = self.quiet_zone
bxs = xpos # x start of barcode
text = {
"start": [], # The x start of a guard
"end": [], # The x end of a guard
"xpos": [], # The x position where to write a text block
# Flag that indicates if the previous mod was part of an guard block:
"was_guard": False,
}
for mod, height_factor in self.packed(line):
if mod < 1:
color = self.background
else:
color = self.foreground
if text["was_guard"] and height_factor == 1:
# The current guard ended, store its x position
text["end"].append(xpos)
text["was_guard"] = False
elif not text["was_guard"] and height_factor != 1:
# A guard started, store its x position
text["start"].append(xpos)
text["was_guard"] = True
self.module_height = base_height * height_factor
# remove painting for background colored tiles?
self._callbacks["paint_module"](
xpos, ypos, self.module_width * abs(mod), color
)
xpos += self.module_width * abs(mod)
else:
if height_factor != 1:
text["end"].append(xpos)
self.module_height = base_height
bxe = xpos
# Add right quiet zone to every line, except last line,
# quiet zone already provided with background,
# should it be removed completely?
if (cc + 1) != len(code):
self._callbacks["paint_module"](
xpos, ypos, self.quiet_zone, self.background
)
ypos += self.module_height
if self.text and self._callbacks["paint_text"] is not None:
if not text["start"]:
# If we don't have any start value, print the entire ean
ypos += self.text_distance
xpos = bxs + (bxe - bxs) / 2.0 if self.center_text else bxs
self._callbacks["paint_text"](xpos, ypos)
else:
# Else, divide the ean into blocks and print each block
# in the expected position.
text["xpos"] = [bxs - 4 * self.module_width]
# Calculates the position of the text by getting the difference
# between a guard end and the next start
text["start"].pop(0)
for s, e in zip(text["start"], text["end"]):
text["xpos"].append(e + (s - e) / 2)
# The last text block is always put after the last guard end
text["xpos"].append(text["end"][-1] + 4 * self.module_width)
# Split the ean into its blocks
self.text = self.text.split(" ")
ypos += pt2mm(self.font_size)
blocks = self.text
for text_, xpos in zip(blocks, text["xpos"]):
self.text = text_
self._callbacks["paint_text"](xpos, ypos)
return self._callbacks["finish"]()
class SVGWriter(BaseWriter):
def __init__(self) -> None:
BaseWriter.__init__(
self, self._init, self._create_module, self._create_text, self._finish
)
self.compress = False
self.with_doctype = True
self._document = None
self._root = None
self._group = None
def _init(self, code):
width, height = self.calculate_size(len(code[0]), len(code))
self._document = create_svg_object(self.with_doctype)
self._root = self._document.documentElement
attributes = {
"width": SIZE.format(width),
"height": SIZE.format(height),
}
_set_attributes(self._root, **attributes)
if COMMENT:
self._root.appendChild(self._document.createComment(COMMENT))
# create group for easier handling in 3rd party software
# like corel draw, inkscape, ...
group = self._document.createElement("g")
attributes = {"id": "barcode_group"}
_set_attributes(group, **attributes)
self._group = self._root.appendChild(group)
background = self._document.createElement("rect")
attributes = {
"width": "100%",
"height": "100%",
"style": f"fill:{self.background}",
}
_set_attributes(background, **attributes)
self._group.appendChild(background)
def _create_module(self, xpos, ypos, width, color):
# Background rect has been provided already, so skipping "spaces"
if color != self.background:
element = self._document.createElement("rect")
attributes = {
"x": SIZE.format(xpos),
"y": SIZE.format(ypos),
"width": SIZE.format(width),
"height": SIZE.format(self.module_height),
"style": f"fill:{color};",
}
_set_attributes(element, **attributes)
self._group.appendChild(element)
def _create_text(self, xpos, ypos):
# check option to override self.text with self.human (barcode as
# human readable data, can be used to print own formats)
barcodetext = self.human if self.human != "" else self.text
for subtext in barcodetext.split("\n"):
element = self._document.createElement("text")
attributes = {
"x": SIZE.format(xpos),
"y": SIZE.format(ypos),
"style": "fill:{};font-size:{}pt;text-anchor:middle;".format(
self.foreground,
self.font_size,
),
}
_set_attributes(element, **attributes)
text_element = self._document.createTextNode(subtext)
element.appendChild(text_element)
self._group.appendChild(element)
ypos += pt2mm(self.font_size) + self.text_line_distance
def _finish(self):
if self.compress:
return self._document.toxml(encoding="UTF-8")
return self._document.toprettyxml(
indent=4 * " ", newl=os.linesep, encoding="UTF-8"
)
def save(self, filename, output):
if self.compress:
_filename = f"{filename}.svgz"
f = gzip.open(_filename, "wb")
f.write(output)
f.close()
else:
_filename = f"{filename}.svg"
with open(_filename, "wb") as f:
f.write(output)
return _filename
def write(self, content, fp: BinaryIO):
"""Write `content` into a file-like object.
Content should be a barcode rendered by this writer.
"""
fp.write(content)
if Image is None:
ImageWriter = None
else:
class ImageWriter(BaseWriter): # type: ignore[no-redef]
format: str
mode: str
dpi: int
def __init__(self, format="PNG", mode="RGB") -> None:
"""Initialise a new write instance.
:params format: The file format for the generated image. This parameter can
take any value that Pillow accepts.
:params mode: The colour-mode for the generated image. Set this to RGBA if
you wish to use colours with transparency.
"""
BaseWriter.__init__(
self, self._init, self._paint_module, self._paint_text, self._finish
)
self.format = format
self.mode = mode
self.dpi = 300
self._image = None
self._draw = None
def _init(self, code):
width, height = self.calculate_size(len(code[0]), len(code))
size = (int(mm2px(width, self.dpi)), int(mm2px(height, self.dpi)))
self._image = Image.new(self.mode, size, self.background)
self._draw = ImageDraw.Draw(self._image)
def _paint_module(self, xpos, ypos, width, color):
size = [
(mm2px(xpos, self.dpi), mm2px(ypos, self.dpi)),
(
mm2px(xpos + width, self.dpi) - 1,
mm2px(ypos + self.module_height, self.dpi),
),
]
self._draw.rectangle(size, outline=color, fill=color)
def _paint_text(self, xpos, ypos):
font_size = int(mm2px(pt2mm(self.font_size), self.dpi))
font = ImageFont.truetype(self.font_path, font_size)
for subtext in self.text.split("\n"):
pos = (
mm2px(xpos, self.dpi),
mm2px(ypos, self.dpi),
)
self._draw.text(
pos, subtext, font=font, fill=self.foreground, anchor="md"
)
ypos += pt2mm(self.font_size) / 2 + self.text_line_distance
def _finish(self):
return self._image
def save(self, filename, output):
filename = f"{filename}.{self.format.lower()}"
output.save(filename, self.format.upper())
return filename
def write(self, content, fp: BinaryIO):
"""Write `content` into a file-like object.
Content should be a barcode rendered by this writer.
"""
content.save(fp, format=self.format)
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