Files
Fulfillment-Backend/barcodes/pdf/generator.py
2024-06-02 13:41:42 +03:00

128 lines
5.0 KiB
Python

import os
from io import BytesIO
from reportlab.graphics.barcode import code128
from reportlab.lib.pagesizes import mm
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak
from constants import APP_PATH
class PDFGenerator:
def __init__(self):
ASSETS_FOLDER = os.path.join(APP_PATH, 'assets')
FONTS_FOLDER = os.path.join(ASSETS_FOLDER, 'fonts')
FONT_FILE_PATH = os.path.join(FONTS_FOLDER, 'DejaVuSans.ttf')
self.page_width = 58 * mm
self.page_height = 40 * mm
pdfmetrics.registerFont(TTFont('DejaVuSans', FONT_FILE_PATH))
# Get standard styles and create a new style with a smaller font size
styles = getSampleStyleSheet()
self.small_style = ParagraphStyle(
'Small',
parent=styles['Normal'],
fontName='DejaVuSans', # Specify the new font
fontSize=6,
leading=7,
spaceAfter=2,
leftIndent=2,
rightIndent=2
)
def generate_small_text(self, barcode_value, text, num_duplicates=1):
buffer = BytesIO()
# Create document with specified page size
doc = SimpleDocTemplate(buffer,
pagesize=(self.page_width, self.page_height),
rightMargin=1 * mm,
leftMargin=1 * mm,
topMargin=1 * mm,
bottomMargin=1 * mm)
# Create paragraph with new style
paragraph = Paragraph(text, self.small_style)
# Get the width and height of the paragraph
paragraph_width, paragraph_height = paragraph.wrap(self.page_width - 2 * mm, self.page_height)
# Create barcode
barcode_height = (self.page_height - paragraph_height * mm)
available_width = self.page_width - 2 * mm # Adjust for margins
# Approximate number of elements in a Code 128 barcode for average length
num_elements = 11 * len(barcode_value) # Rough estimate: 11 elements per character
# Calculate barWidth
bar_width = available_width / num_elements
barcode = code128.Code128(barcode_value,
barWidth=bar_width,
barHeight=barcode_height,
humanReadable=True)
# Function to draw barcode on canvas
def add_barcode(canvas, doc):
barcode_width = barcode.width
barcode_x = (self.page_width - barcode_width) / 2 # Center the barcode
barcode.drawOn(canvas, barcode_x, self.page_height - barcode.height - 5)
# Create list of elements to add to the document
elements = []
for _ in range(num_duplicates):
elements.append(Spacer(1, barcode_height + 2 * mm))
elements.append(paragraph)
elements.append(PageBreak())
# Build document
doc.build(elements[:-1], onFirstPage=add_barcode, onLaterPages=add_barcode) # Remove the last PageBreak
buffer.seek(0)
return buffer
def generate_large_text(self, barcode_value, text, num_duplicates=1):
buffer = BytesIO()
# Create document with specified page size
doc = SimpleDocTemplate(buffer,
pagesize=(self.page_width, self.page_height),
rightMargin=1 * mm,
leftMargin=1 * mm,
topMargin=1 * mm,
bottomMargin=1 * mm)
# Create paragraph with new style
paragraph = Paragraph(text, self.small_style)
# Create barcode
barcode = code128.Code128(barcode_value, humanReadable=True)
# Function to draw barcode on canvas
def add_barcode(canvas, doc):
barcode_width = barcode.width
barcode_x = (self.page_width - barcode_width) / 2 # Center the barcode
barcode.drawOn(canvas, barcode_x, self.page_height - barcode.height - 5)
# Create list of elements to add to the document
elements = []
for _ in range(num_duplicates):
elements.append(Spacer(1, 8 * mm))
elements.append(paragraph)
elements.append(PageBreak())
# Build document
doc.build(elements[:-1], onFirstPage=add_barcode, onLaterPages=add_barcode) # Remove the last PageBreak
buffer.seek(0)
return buffer
def generate(self, barcode_value, text, num_duplicates=1):
paragraph = Paragraph(text, self.small_style)
# Get the width and height of the paragraph
paragraph_width, paragraph_height = paragraph.wrap(self.page_width - 2 * mm, self.page_height)
if paragraph_height > 30:
return self.generate_large_text(barcode_value, text, num_duplicates)
return self.generate_small_text(barcode_value, text, num_duplicates)