#!/usr/bin/python # -*- coding: utf-8 -*- """This module contains the implementation of the Win32Raw printer driver. :author: python-escpos developers :organization: `python-escpos `_ :copyright: Copyright (c) 2012-2023 Bashlinux and python-escpos :license: MIT """ import functools import logging from typing import Literal, Optional, Type, 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 win32print _DEP_WIN32PRINT = True 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 class Win32Raw(Escpos): """Printer binding for win32 API. Uses the module pywin32 for printing. inheritance: .. inheritance-diagram:: escpos.printer.Win32Raw :parts: 1 """ @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() @dependency_win32print def __init__(self, printer_name: str = "", *args, **kwargs): """Initialize default printer.""" Escpos.__init__(self, *args, **kwargs) self.printer_name = printer_name self.job_name = "" self._device: Union[ Literal[False], Literal[None], Type[win32print.OpenPrinter], ] = False @property def printers(self) -> dict: """Available Windows printers.""" return { printer["pPrinterName"]: printer for printer in win32print.EnumPrinters(win32print.PRINTER_ENUM_NAME, "", 4) } 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[ Type[win32print.OpenPrinter] ] = win32print.OpenPrinter(self.printer_name) if self.device: self.current_job = win32print.StartDocPrinter( self.device, 1, (job_name, None, "RAW") ) win32print.StartPagePrinter(self.device) except AssertionError 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") 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): """Print any command sent in raw format. :param msg: arbitrary code to be printed :type msg: bytes """ 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)