#!/usr/bin/python
# -*- coding: utf-8 -*-
"""This module contains the implementation of the Win32Raw printer driver.
:author: python-escpos developers
:organization: `python-escpos <https://github.com/python-escpos>`_
:copyright: Copyright (c) 2012-2023 Bashlinux and python-escpos
:license: MIT
"""
import functools
import logging
from typing import Any, Literal, Optional, Union
from ..escpos import Escpos
from ..exceptions import DeviceNotFoundError
#: keeps track if the win32print dependency could be loaded (:py:class:`escpos.printer.Win32Raw`)
_DEP_WIN32PRINT = False
try:
import pywintypes
import win32print
_DEP_WIN32PRINT = True
PyPrinterHANDLE: Any = win32print.OpenPrinter
except ImportError:
pass
def is_usable() -> bool:
"""Indicate whether this component can be used due to dependencies."""
usable = False
if _DEP_WIN32PRINT:
usable = True
return usable
def dependency_win32print(func):
"""Indicate dependency on win32print."""
@functools.wraps(func)
def wrapper(*args, **kwargs):
"""Throw a RuntimeError if win32print not installed."""
if not is_usable():
raise RuntimeError(
"Printing with Win32Raw requires a win32print library to "
"be installed. Please refer to the documentation on "
"what to install and install the dependencies for win32print."
)
return func(*args, **kwargs)
return wrapper
[docs]
class Win32Raw(Escpos):
"""Printer binding for win32 API.
Uses the module pywin32 for printing.
inheritance:
.. inheritance-diagram:: escpos.printer.Win32Raw
:parts: 1
"""
[docs]
@staticmethod
def is_usable() -> bool:
"""Indicate whether this printer class is usable.
Will return True if dependencies are available.
Will return False if not.
"""
return is_usable()
[docs]
@dependency_win32print
def __init__(self, printer_name: str = "", *args, **kwargs) -> None:
"""Initialize default printer."""
Escpos.__init__(self, *args, **kwargs)
self.printer_name = printer_name
self.job_name = ""
self._device: Union[
Literal[False],
Literal[None],
"PyPrinterHANDLE",
] = False
@property
def printers(self) -> dict:
"""Available Windows printers."""
return {
printer["pPrinterName"]: printer
for printer in win32print.EnumPrinters(win32print.PRINTER_ENUM_NAME, "", 4)
}
[docs]
def open(
self, job_name: str = "python-escpos", raise_not_found: bool = True
) -> None:
"""Open connection to default printer.
By default raise an exception if device is not found.
:param raise_not_found: Default True.
False to log error but do not raise exception.
:raises: :py:exc:`~escpos.exceptions.DeviceNotFoundError`
"""
if self._device:
self.close()
self.job_name = job_name
try:
# Name validation, set default if no given name
self.printer_name = self.printer_name or win32print.GetDefaultPrinter()
assert self.printer_name in self.printers, "Incorrect printer name"
# Open device
self.device: Optional["PyPrinterHANDLE"] = win32print.OpenPrinter(
self.printer_name
)
if self.device:
self.current_job = win32print.StartDocPrinter(
self.device, 1, (job_name, "", "RAW")
)
win32print.StartPagePrinter(self.device)
except (AssertionError, pywintypes.error) as e:
# Raise exception or log error and cancel
self.device = None
if raise_not_found:
raise DeviceNotFoundError(
f"Unable to start a print job for the printer {self.printer_name}:"
+ f"\n{e}"
)
else:
logging.error("Win32Raw printing %s not available", self.printer_name)
return
logging.info("Win32Raw printer enabled")
[docs]
def close(self) -> None:
"""Close connection to default printer."""
if self._device is False or self._device is None: # Literal False | None
return
logging.info("Closing Win32Raw connection to printer %s", self.printer_name)
win32print.EndPagePrinter(self._device)
win32print.EndDocPrinter(self._device)
win32print.ClosePrinter(self._device)
self._device = False
def _raw(self, msg: bytes) -> None:
"""Print any command sent in raw format.
:param msg: arbitrary code to be printed
"""
if self.printer_name is None:
raise DeviceNotFoundError("Printer not found")
if not self.device:
raise DeviceNotFoundError("Printer job not opened")
win32print.WritePrinter(self.device, msg) # type: ignore
# there is a bug in the typeshed
# https://github.com/mhammond/pywin32/blob/main/win32/src/win32print/win32print.cpp#L976
# https://github.com/python/typeshed/blob/main/stubs/pywin32/win32/win32print.pyi#L27C4-L27C4