# Importing the module to mage the connection to the printer. from flask import flash from escpos.printer import Usb, USBNotFoundError from time import sleep, gmtime, strftime import os.path from PIL import Image class Printer(object): """ # The connection is based on the ESC/POS library ## Connection to the USB printer ## Making sure the printer is alive ## Making sure it has paper ## Define default print settings ## Print starting message, log time of first print, cut. ## Annonce readyness : return a positive pong message. """ # Is the printer ready to accept a new print ? ready = False def __init__(self, app, device_id, vendor_id): super(Printer, self).__init__() self.app = app self.ready = False self.printer = None self.device_id = device_id self.vendor_id = vendor_id self.usb_args = {} self.usb_args['idVendor'] = self.device_id self.usb_args['idProduct'] = self.vendor_id def check_paper(self) -> bool: # Let's check paper status self.app.logger.debug('Checking paper status...') self.printer.open(self.usb_args) status = self.printer.paper_status() match status: case 0: self.app.logger.error('Printer has no more paper, aborting...') flash("No more paper on the printer. Sorry.",category='error') self.printer.close() return False case 1: self.app.logger.warning('Printer needs paper to be changed very soon ! ') flash('Printer needs paper to be changed very soon ! ', category='info') self.printer.close() return True case 2: self.app.logger.debug('Printer has paper, good to go') self.printer.close() return True def init_printer(self): # Is the printer online ? Is the communication with the printer successfull ? waiting_elapsed = 30 self.app.logger.debug('Waiting for printer to get online...') while not self.ready: try: # This also calls open(), which we need to close() # or else the device will appear as busy. p = Usb(self.device_id, self.vendor_id, 0, profile="TM-P80") except USBNotFoundError as e: self.app.logger.error("The USB device is not plugged in, trying again : " + str(e)) pass try: if p.is_online(): self.ready = True self.app.logger.debug('Printer online !') except Exception as e: pass sleep(1) waiting_elapsed -= 1 if waiting_elapsed < 1: self.app.logger.error('Printer took more than 30 seconds to get online, aborting...') waiting_elapsed = 30 # Reset the waiting time for the next print. return False # Setting up the printing options. 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) # Beware : if we print every time the printer becomes ready, it means # we are printing before and after every print ! self.printer = p self.ready = True; self.printer.close(); if not self.check_paper(): return False return True def print_sms(self, msg, signature) -> bool: clean_msg = str(msg) clean_signature = str(signature) if not self.check_paper(): return False if len(clean_msg) > 256 or len(clean_msg) < 3 : self.app.logger.warning("Could not print message of this length: " + str(len(clean_msg))) flash("Could not print message of this length :" + str(len(clean_msg)) + ", needs to between 3 and 256 caracters long.",category='error') return False if len(signature) > 256 or len(signature) < 3: self.app.logger.warning("Could not print message without a signature.") flash("Could not print message without a signature.",category='error') return False if not os.getenv('LIPY_DEBUG') == True: try: self.printer.open(self.usb_args); 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) self.printer.textln(clean_msg) 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) self.printer.textln("> " + clean_signature + " @ " + strftime("%Y-%m-%d %H:%M:%S", gmtime())) self.printer.cut() self.printer.close except Exception as e: flash("Unable to print because : " + e) flash("Message printed : " + clean_msg ,category='info') return True def print_img(self, path, sign): clean_signature = str(sign) if not os.path.isfile(str(path)): self.app.logger.warning("File does not exist : " + str(path)) flash('The file path for this image :' + str(path) + " wasn't found. Please try again.", 'error') return False else: self.app.logger.debug("Printing file from " + str(path)) try: self.app.logger.debug("Resizing the image") with Image.open(path) as im: basewidth = 575 img = Image.open(path) wpercent = (basewidth/float(img.size[0])) hsize = int((float(img.size[1])*float(wpercent))) img = img.resize((basewidth,hsize), Image.ANTIALIAS) if img.height > 1000: flash("Image is too long, sorry ! Keep it below 500×1000 pixels.",'error') return False img.save(path) except Exception as e: flash(str(e)) self.app.logger.error(str(e)) try: self.printer.open(self.usb_args) self.printer.textln("> " + clean_signature + " @ " + strftime("%Y-%m-%d %H:%M:%S", gmtime())) self.printer.image(path) self.printer.cut() self.printer.close() self.app.logger.debug("Printed an image : " + str(path)) return True except Exception as e: self.printer.close() flash(str(e),'error') return False