python-escpos/escpos/printer.py

#!/usr/bin/python
""" This module contains the implentations of abstract base class :py:class:`Escpos`.

:author: `Manuel F Martinez <manpaz@bashlinux.com>`_ and others
:organization: Bashlinux and `python-escpos <https://github.com/python-escpos>`_
:copyright: Copyright (c) 2012 Bashlinux
:license: GNU GPL v3
"""

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

import usb.core
import usb.util
import serial
import socket

from .escpos import Escpos
from .exceptions import *

class Usb(Escpos):
    """ USB printer

    This class describes a printer that natively speaks USB.

    inheritance:

    .. inheritance-diagram:: escpos.printer.Usb
        :parts: 1

    """

    def __init__(self, idVendor, idProduct, interface=0, in_ep=0x82, out_ep=0x01, *args, **kwargs):
        """
        :param idVendor: Vendor ID
        :param idProduct: Product ID
        :param interface: USB device interface
        :param in_ep: Input end point
        :param out_ep: Output end point
        """
        Escpos.__init__(self, *args, **kwargs)
        self.idVendor = idVendor
        self.idProduct = idProduct
        self.interface = interface
        self.in_ep = in_ep
        self.out_ep = out_ep
        self.open()

    def open(self):
        """ Search device on USB tree and set it as escpos device """
        self.device = usb.core.find(idVendor=self.idVendor, idProduct=self.idProduct)
        if self.device is None:
            raise USBNotFoundError("Device not found or cable not plugged in.")

        check_driver = None

        try:
            check_driver = self.device.is_kernel_driver_active(0)
        except NotImplementedError:
            pass

        if check_driver is None or check_driver:
            try:
                self.device.detach_kernel_driver(0)
            except usb.core.USBError as e:
                if check_driver is not None:
                    print("Could not detatch kernel driver: {0}".format(str(e)))

        try:
            self.device.set_configuration()
            self.device.reset()
        except usb.core.USBError as e:
            print("Could not set configuration: {0}".format(str(e)))

    def _raw(self, msg):
        """ Print any command sent in raw format

        :param msg: arbitrary code to be printed
        :type msg: bytes
        """
        self.device.write(self.out_ep, msg, self.interface)

    def __del__(self):
        """ Release USB interface """
        if self.device:
            usb.util.dispose_resources(self.device)
        self.device = None


class Serial(Escpos):
    """ Serial printer

    This class describes a printer that is connected by serial interface.

    inheritance:

    .. inheritance-diagram:: escpos.printer.Serial
        :parts: 1

    """

    def __init__(self, devfile="/dev/ttyS0", baudrate=9600, bytesize=8, timeout=1,
                 parity=serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE,
                 xonxoff=False, dsrdtr=True, *args, **kwargs):
        """

        :param devfile:  Device file under dev filesystem
        :param baudrate: Baud rate for serial transmission
        :param bytesize: Serial buffer size
        :param timeout:  Read/Write timeout
        :param parity:   Parity checking
        :param stopbits: Number of stop bits
        :param xonxoff:  Software flow control
        :param dsrdtr:   Hardware flow control (False to enable RTS/CTS)
        """
        Escpos.__init__(self, *args, **kwargs)
        self.devfile = devfile
        self.baudrate = baudrate
        self.bytesize = bytesize
        self.timeout = timeout
        self.parity = parity
        self.stopbits = stopbits
        self.xonxoff = xonxoff
        self.dsrdtr = dsrdtr

        self.open()

    def open(self):
        """ Setup serial port and set is as escpos device """
        self.device = serial.Serial(port=self.devfile, baudrate=self.baudrate,
                                    bytesize=self.bytesize, parity=self.parity,
                                    stopbits=self.stopbits, timeout=self.timeout,
                                    xonxoff=self.xonxoff, dsrdtr=self.dsrdtr)

        if self.device is not None:
            print("Serial printer enabled")
        else:
            print("Unable to open serial printer on: {0}".format(str(self.devfile)))

    def _raw(self, msg):
        """ Print any command sent in raw format

        :param msg: arbitrary code to be printed
        :type msg: bytes
        """
        self.device.write(msg)

    def __del__(self):
        """ Close Serial interface """
        if self.device is not None:
            self.device.flush()
            self.device.close()


class Network(Escpos):
    """ Network printer

    This class is used to attach to a networked printer. You can also use this in order to attach to a printer that
    is forwarded with ``socat``.

    If you have a local printer on parallel port ``/dev/usb/lp0`` then you could start ``socat`` with:

    .. code-block:: none

        socat -u TCP4-LISTEN:4242,reuseaddr,fork OPEN:/dev/usb/lp0

    Then you should be able to attach to port ``4242`` with this class.
    Otherwise the normal usecase would be to have a printer with ethernet interface. This type of printer should
    work the same with this class. For the address of the printer check its manuals.

    inheritance:

    .. inheritance-diagram:: escpos.printer.Network
        :parts: 1

    """

    def __init__(self, host, port=9100, timeout=60, *args, **kwargs):
        """

        :param host : Printer's hostname or IP address
        :param port : Port to write to
        :param timeout : timeout in seconds for the socket-library
        """
        Escpos.__init__(self, *args, **kwargs)
        self.host = host
        self.port = port
        self.timeout = timeout
        self.open()

    def open(self):
        """ Open TCP socket with ``socket``-library and set it as escpos device """
        self.device = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.device.settimeout(self.timeout)
        self.device.connect((self.host, self.port))

        if self.device is None:
            print("Could not open socket for {0}".format(self.host))

    def _raw(self, msg):
        """ Print any command sent in raw format

        :param msg: arbitrary code to be printed
        :type msg: bytes
        """
        self.device.sendall(msg)

    def __del__(self):
        """ Close TCP connection """
        self.device.shutdown(socket.SHUT_RDWR)
        self.device.close()


class File(Escpos):
    """ Generic file printer

    This class is used for parallel port printer or other printers that are directly attached to the filesystem.
    Note that you should stay away from using USB-to-Parallel-Adapter since they are unreliable
    and produce arbitrary errors.

    inheritance:

    .. inheritance-diagram:: escpos.printer.File
        :parts: 1

    """

    def __init__(self, devfile="/dev/usb/lp0", *args, **kwargs):
        """

        :param devfile : Device file under dev filesystem
        """
        Escpos.__init__(self, *args, **kwargs)
        self.devfile = devfile
        self.open()

    def open(self):
        """ Open system file """
        self.device = open(self.devfile, "wb")

        if self.device is None:
            print("Could not open the specified file {0}".format(self.devfile))

    def flush(self):
        """ Flush printing content """
        self.device.flush()

    def _raw(self, msg):
        """ Print any command sent in raw format

        :param msg: arbitrary code to be printed
        :type msg: bytes
        """
        self.device.write(msg)

    def __del__(self):
        """ Close system file """
        self.device.flush()
        self.device.close()

class Dummy(Escpos):
    """ Dummy printer

    This class is used for saving commands to a variable, for use in situations where
    there is no need to send commands to an actual printer. This includes
    generating print jobs for later use, or testing output.

    inheritance:

    .. inheritance-diagram:: escpos.printer.Dummy
        :parts: 1

    """

    def __init__(self, *args, **kwargs):
        """

        :param devfile : Device file under dev filesystem
        """
        Escpos.__init__(self, *args, **kwargs)
        self._output_list = []

    def _raw(self, msg):
        """ Print any command sent in raw format

        :param msg: arbitrary code to be printed
        :type msg: bytes
        """
        self._output_list.append(msg)

    @property
    def output(self):
        return b''.join(self._output_list)