226 lines
9.5 KiB
Python
226 lines
9.5 KiB
Python
# Importing the module to mage the connection to the printer.
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from flask import flash
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from escpos.printer import Usb, USBNotFoundError
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from time import sleep, gmtime, strftime
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import os.path
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from PIL import Image, ImageEnhance, ImageOps
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import numpy as np
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class Printer(object):
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"""
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# The connection is based on the ESC/POS library
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## Connection to the USB printer
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## Making sure the printer is alive
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## Making sure it has paper
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## Define default print settings
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## Print starting message, log time of first print, cut.
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## Annonce readyness : return a positive pong message.
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"""
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# Is the printer ready to accept a new print ?
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ready = False
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def __init__(self, app, device_id, vendor_id):
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super(Printer, self).__init__()
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self.app = app
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self.ready = False
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self.printer = None
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self.device_id = device_id
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self.vendor_id = vendor_id
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self.usb_args = {}
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self.usb_args['idVendor'] = self.device_id
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self.usb_args['idProduct'] = self.vendor_id
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def check_paper(self) -> bool:
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# Let's check paper status
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self.app.logger.debug('Checking paper status...')
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self.printer.open(self.usb_args)
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status = self.printer.paper_status()
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match status:
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case 0:
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self.app.logger.error('Printer has no more paper, aborting...')
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flash("No more paper on the printer. Sorry.",category='error')
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self.printer.close()
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raise Exception("No more paper in the printer")
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case 1:
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self.app.logger.warning('Printer needs paper to be changed very soon ! ')
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flash('Printer needs paper to be changed very soon ! ', category='info')
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self.printer.close()
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case 2:
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self.app.logger.debug('Printer has paper, good to go')
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self.printer.close()
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def init_printer(self):
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# Is the printer online ? Is the communication with the printer successfull ?
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waiting_elapsed = 30
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self.app.logger.debug('Waiting for printer to get online...')
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while not self.ready:
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try:
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# This also calls open(), which we need to close()
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# or else the device will appear as busy.
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p = Usb(self.device_id, self.vendor_id, 0, profile="TM-P80")
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except USBNotFoundError as e:
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self.app.logger.error("The USB device is not plugged in, trying again : " + str(e))
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pass
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try:
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if p.is_online():
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self.ready = True
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self.app.logger.debug('Printer online !')
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except Exception as e:
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pass
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sleep(1)
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waiting_elapsed -= 1
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if waiting_elapsed < 1:
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self.app.logger.error('Printer took more than 30 seconds to get online, aborting...')
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waiting_elapsed = 30 # Reset the waiting time for the next print.
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return False
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# Setting up the printing options.
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p.set(align='center', font='a', bold=False, underline=0, width=1, height=1, density=9, invert=False, smooth=False, flip=False, double_width=False, double_height=False, custom_size=False)
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# Beware : if we print every time the printer becomes ready, it means
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# we are printing before and after every print !
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self.printer = p
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self.ready = True;
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self.printer.close();
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self.check_paper()
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return True
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def print_sms(self, msg, signature) -> None:
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clean_msg = str(msg)
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clean_signature = str(signature)
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if len(clean_msg) > 4096 or len(clean_msg) < 3 :
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self.app.logger.warning("Could not print message of this length: " + str(len(clean_msg)))
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raise Exception("Could not print message of this length :" + str(len(clean_msg)) + ", needs to between 3 and 4096 caracters long.")
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if len(signature) > 256 or len(signature) < 3:
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self.app.logger.warning("Could not print signature of this length: " + str(len(clean_signature)))
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raise Exception("Could not print signature of this length :" + str(len(clean_signature)) + ", needs to between 3 and 256 caracters long.")
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self.check_paper()
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try:
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self.printer.open(self.usb_args);
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self.printer.set(align='left', font='a', bold=False, underline=0, width=1, height=1, density=8, invert=False, smooth=True, flip=False, double_width=False, double_height=False, custom_size=False)
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self.printer.set(align='left', font='a', bold=True, underline=1, width=1, height=1, density=6, invert=False, smooth=True, flip=False, double_width=False, double_height=False, custom_size=False)
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self.printer.textln(clean_msg)
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self.printer.textln("")
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self.printer.set(align='left', font='b', bold=False, underline=1, width=1, height=1, density=9, invert=False, smooth=True, flip=False, double_width=False, double_height=False, custom_size=False)
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self.printer.textln("> " + clean_signature + " @ " + strftime("%Y-%m-%d %H:%M:%S", gmtime()))
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self.printer.textln("")
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self.printer.textln("Printed by LittlePrinter ")
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self.printer.textln("n07070.xyz/articles/littleprynter")
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self.printer.textln("")
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self.printer.cut()
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self.printer.close()
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except Exception as e:
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self.app.logger.error("Unable to print because : " + str(e))
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raise e
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flash("Message printed : " + clean_msg ,category='info')
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return True
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def print_img(self, path, sign) -> None:
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clean_signature = str(sign)
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if len(sign) > 256 or len(sign) < 3:
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self.app.logger.warning("Could not print signature of this length: " + str(len(clean_signature)))
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raise Exception("Could not print signature of this length :" + str(len(clean_signature)) + ", needs to between 3 and 256 caracters long.")
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if not os.path.isfile(str(path)):
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self.app.logger.warning("File does not exist : " + str(path))
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raise Exception('The file path for this image :' + str(path) + " wasn't found. Please try again.")
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else:
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self.app.logger.debug("Printing file from " + str(path))
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try:
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self.app.logger.debug("Proccessing the image")
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path = process_image(self, path)
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except Exception as e:
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self.app.logger.error(str(e))
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raise e
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try:
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self.check_paper()
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self.printer.open(self.usb_args)
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self.printer.textln("Printed by LittlePrinter ")
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self.printer.textln("n07070.xyz/articles/littleprynter")
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self.printer.textln("> " + clean_signature + " @ " + strftime("%Y-%m-%d %H:%M:%S", gmtime()))
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self.printer.image(path)
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self.printer.cut()
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self.printer.close()
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self.app.logger.debug("Printed an image : " + str(path))
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os.remove(path)
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self.app.logger.debug("Removed image.")
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except Exception as e:
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self.printer.close()
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self.app.logger.error(str(e))
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raise e
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def process_image(self, path):
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brightness_factor = 1.5 # Used only if image is too dark
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brightness_threshold = 100 # Brightness threshold (0–255)
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contrast_factor = 0.6 # Less than 1.0 = lower contrast
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max_width = 575
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max_height = 1000
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with Image.open(path) as original_img:
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# Convert to RGB if needed (JPEG doesn't support alpha)
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if original_img.mode in ("RGBA", "P"):
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self.app.logger.debug("Converting the image to RGB from RGBA")
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original_img = original_img.convert("RGB")
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# Resize while maintaining aspect ratio
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original_img.thumbnail((max_width, max_height), Image.LANCZOS)
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self.app.logger.debug("Resized the image")
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# Convert to grayscale for dithering
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dithered_img = original_img.convert("L").convert("1") # Dithering using default method (Floyd–Steinberg)
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self.app.logger.debug("Dithered the image")
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# Compute brightness of original image (grayscale average)
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grayscale = original_img.convert("L")
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avg_brightness = np.array(grayscale).mean()
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self.app.logger.debug("Average brightness of the image : " + str(avg_brightness) )
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# Dynamically compute brightness factor if too dark
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if avg_brightness < brightness_threshold:
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brightness_factor = 1 + (brightness_threshold - avg_brightness) / brightness_threshold
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brightness_factor = min(max(brightness_factor, 1.1), 2.5) # Clamp between 1.1 and 2.5
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self.app.logger.debug(f"Image too dark, increasing brightness by a factor of {brightness_factor:.2f}")
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enhancer = ImageEnhance.Brightness(original_img)
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original_img = enhancer.enhance(brightness_factor)
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# Reduce contrast
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contrast_enhancer = ImageEnhance.Contrast(original_img)
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original_img = contrast_enhancer.enhance(contrast_factor)
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# Final resize check
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if original_img.height > max_height:
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flash("Image is too long, sorry! Keep it below 575×1000 pixels.", 'error')
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self.app.logger.error("Image is too long, sorry! Keep it below 575×1000 pixels.")
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return False
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# Convert to JPEG and save
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jpeg_path = os.path.splitext(path)[0] + "_processed.jpg"
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original_img.save(jpeg_path, format='JPEG', quality=95, optimize=True)
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return jpeg_path
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