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Change the Printer class to implement multiple printer types

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n07070
2026-06-01 21:40:13 +02:00
parent 0e3cc46a41
commit 9e77e0980b
3 changed files with 132 additions and 62 deletions
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1
src/main.py
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@@ -101,7 +101,6 @@ app.config["TEMPLATES_AUTO_RELOAD"] = True
# Printer connection
# Uses the class defined in the printer.py file
printer = Printer(app, 0x04B8, 0x0E28)
printer.init_printer()
# Find out if we are running on a Raspberry Pi
rpi = Raspberry(

175
src/printer.py
View File

@@ -4,15 +4,54 @@ This class manages connexion to a Printer
# import brother_ql
from time import sleep
import os.path
from abc import ABC, abstractmethod
from enum import Enum
import uuid
from PIL import Image, ImageEnhance
import numpy as np
# Importing the module to manage the connection to the printer.
# Importing the modules needed for each supported printer Type
import escpos.printer
import brother_ql
class PrinterCapabilities(Enum):
"""
What are the capacities of a Printer ?
"""
class Printer():
class Printer(ABC):
"""
If it outputs printed paper and speaks like a printer, then it must be a printer.
"""
def __init__(self, app, vendor_id, device_id):
"""
We initialize a Printer via it's USB connexion, and generate a unique ID
"""
self.id = uuid.uuid4()
self.app = app
self.vendor_id = vendor_id
self.device_id = device_id
self.ready = False
@abstractmethod
def _has_paper(self) -> bool:
"""Check if the printer has papier"""
@abstractmethod
def _state(self) -> bool:
"""Reports the state of the Printer"""
@abstractmethod
def print_task(self, task_type, data)-> None:
"""Takes a PrintTask and executes it"""
class EscPosPrinter(Printer):
"""
# The connection is based on the ESC/POS library
@@ -29,47 +68,13 @@ class Printer():
## 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().__init__()
self.app = app
self.ready = False
def __init__(self, app):
super().__init__(app, vendor_id="",device_id="")
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:
"""
On printers that support it, we check that the printer has paper
"""
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...")
self.printer.close()
raise RuntimeError("No more paper in the printer")
case 1:
self.app.logger.warning(
"Printer needs paper to be changed very soon ! "
)
self.printer.close()
case 2:
self.app.logger.debug("Printer has paper, good to go")
self.printer.close()
def init_printer(self):
"""
Check if the printer online ? Is the communication with the printer successfull ?
"""
# TODO: This could happen directly when creating a new Printer class
if os.getenv("FLASK_DEBUG"):
waiting_elapsed = 3
else:
@@ -77,14 +82,15 @@ class Printer():
self.app.logger.debug("Waiting for printer to get online...")
while not self.ready:
online = False
while not online:
try:
# This also calls open(), which we need to close()
# or else the device will appear as busy.
p = escpos.printer.Usb(
self.device_id, self.vendor_id, 0, profile="TM-P80"
)
except RuntimeError as e:
except escpos.exceptions.DeviceNotFoundError as e:
self.app.logger.error(
"The USB device is not plugged in, trying again %s : %s",
waiting_elapsed,
@@ -93,9 +99,9 @@ class Printer():
try:
if p.is_online():
self.ready = True
online = True
self.app.logger.debug("Printer online !")
except RuntimeError as e:
except escpos.exceptions.DeviceNotFoundError as e:
self.app.logger.error(
"Error while getting the printer online %s : %s",
waiting_elapsed,
@@ -109,7 +115,7 @@ class Printer():
"Printer took more than 30 seconds to get online, aborting..."
)
waiting_elapsed = 1 # Reset the waiting time for the next print.
return False
raise RuntimeError("Could not get Printer %s online" % self.id)
# Setting up the printing options.
p.set(
@@ -130,14 +136,37 @@ class Printer():
# Beware : if we print every time the printer becomes ready, it means
# we are printing before and after every print !
self.printer = p
self.printer.close() # We close the connexion to the Printer
try:
self._has_paper()
except Exception as e:
raise e
self.ready = True
self.printer.close()
self.check_paper()
def _has_paper(self):
"""Check if the printer has paper left"""
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...")
self.printer.close()
raise RuntimeError("No more paper in the printer")
case 1:
self.app.logger.warning(
"Printer needs paper to be changed very soon ! "
)
self.printer.close()
return True
case 2:
self.app.logger.debug("Printer has paper, good to go")
self.printer.close()
return True
return True
def _print_sms(self, msg, signature="", bold=False):
def _print_txt(self, msg, signature="", bold=False):
if not isinstance(msg, str):
self.app.logger.error(
@@ -255,14 +284,14 @@ class Printer():
try:
self.printer.open(self.usb_args)
self.printer.qr(content, center=True)
self.printer.textln(content, center=True)
self.printer.close()
except RuntimeError as e:
self.printer.close()
self.app.logger.error(str(e))
return False
raise e
self.app.logger.info("Printed a QR")
return True
def _cut(self):
try:
@@ -277,21 +306,45 @@ class Printer():
self.app.logger.info("Did a cut")
return True
def _state(self):
return self.printer.is_online() and self.ready and self._has_paper()
def print_task(self, task_type, data):
"""Execute actual print based on task type"""
match (task_type.value):
case "text":
self._print_sms(data["txt"], signature=data["sign"])
case "image":
self._print_img(
data["img"], signature=data["sign"], process=data["process"]
)
case "cut":
self._cut()
case _:
raise RuntimeError("This task type is not supported")
if self._state():
match (task_type.value):
case "text":
self._print_txt(data["txt"], signature=data["sign"])
case "image":
self._print_img(
data["img"], signature=data["sign"], process=data["process"]
)
case "cut":
self._cut()
case "qr":
self._qr(data["txt"])
case _:
raise RuntimeError("This task type is not supported")
class BrotherPrinter(Printer):
"""
Manages connexion and capabilities of a BrotherQL Printer
"""
def __init__(self, app, vendor_id, device_id):
super().__init__(app, vendor_id="",device_id="")
self.printer = None
self.usb_args = {}
self.usb_args["idVendor"] = self.device_id
self.usb_args["idProduct"] = self.vendor_id
def _has_paper():
def _state():
def print_task():
def _process_image(self, path):
brightness_factor = 1.5 # Used only if image is too dark
brightness_threshold = 100 # Brightness threshold (0–255)

18
src/printers.py Normal file
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@@ -0,0 +1,18 @@
"""
A collection of Printers.
It has methods to discover printers, and provides an interface for the methods expected from printers.
"""
from printer import Printer
class Printers():
"""
A collection of Printers
"""
def __init__(self, name, age):
self.name = name
self.age = age
def _discover_printers(self):
pass