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DOC, IMPROVE improve docstrings and add abstract method _raw to Escpos

This commit is contained in:
Patrick Kanzler 2015-11-27 23:10:20 +01:00
parent 8b5798eedf
commit 0dacc35d94
3 changed files with 105 additions and 23 deletions
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106
escpos/escpos.py
View File

@ -16,25 +16,47 @@ import qrcode
from constants import *
from exceptions import *
from abc import ABCMeta, abstractmethod # abstract base class support
class Escpos(object):
""" ESC/POS Printer object """
__metaclass__ = ABCMeta
device = None
@abstractmethod
def _raw(self, msg):
""" Sends raw data to the printer
This function has to be individually implemented by the implementations.
:param msg: message string to be sent to the printer
"""
pass
@staticmethod
def _check_image_size(size):
""" Check and fix the size of the image to 32 bits """
""" Check and fix the size of the image to 32 bits
:param size: size of the image
:returns: tuple of image borders
:rtype: (int, int)
"""
if size % 32 == 0:
return 0, 0
else:
image_border = 32 - (size % 32)
if (image_border % 2) == 0:
# TODO check behaviour of / in newer versions of python
return image_border / 2, image_border / 2
else:
return image_border / 2, (image_border / 2) + 1
def _print_image(self, line, size):
""" Print formatted image """
""" Print formatted image
:param line:
:param size:
"""
i = 0
cont = 0
pbuffer = ""
@ -55,7 +77,11 @@ class Escpos(object):
cont = 0
def _convert_image(self, im):
""" Parse image and prepare it to a printable format """
""" Parse image and prepare it to a printable format
:param im: image data
:raises: ImageSizeError
"""
pixels = []
pix_line = ""
im_left = ""
@ -101,7 +127,10 @@ class Escpos(object):
self._print_image(pix_line, img_size)
def image(self, path_img):
""" Open image file """
""" Open image file
:param path_img: path to image
"""
im_open = Image.open(path_img)
# Remove the alpha channel on transparent images
@ -116,7 +145,10 @@ class Escpos(object):
self._convert_image(im)
def qr(self, text):
""" Print QR Code for the provided string """
""" Print QR Code for the provided string
:param text: text to generate a QR-Code from
"""
qr_code = qrcode.QRCode(version=4, box_size=4, border=1)
qr_code.add_data(text)
qr_code.make(fit=True)
@ -127,7 +159,13 @@ class Escpos(object):
self._convert_image(im)
def charcode(self, code):
""" Set Character Code Table """
""" Set Character Code Table
Sends the control sequence from constants.py to the printer with :py:meth:`escpos.printer._raw()`.
:param code: Name of CharCode
:raises: CharCodeError
"""
if code.upper() == "USA":
self._raw(CHARCODE_PC437)
elif code.upper() == "JIS":
@ -146,8 +184,8 @@ class Escpos(object):
self._raw(CHARCODE_GREEK)
elif code.upper() == "HEBREW":
self._raw(CHARCODE_HEBREW)
elif code.upper() == "LATVIAN":
self._raw(CHARCODE_PC755)
# elif code.upper() == "LATVIAN": # this is not listed in the constants
# self._raw(CHARCODE_PC755)
elif code.upper() == "WPC1252":
self._raw(CHARCODE_PC1252)
elif code.upper() == "CIRILLIC2":
@ -174,7 +212,16 @@ class Escpos(object):
raise CharCodeError()
def barcode(self, code, bc, width, height, pos, font):
""" Print Barcode """
""" Print Barcode
:param code: data for barcode
:param bc: barcode format, see constants.py
:param width: barcode width, has to be between 1 and 255
:param height: barcode height, has to be between 2 and 6
:param pos: position of text in barcode, default when nothing supplied is below
:param font: select font, default is font A
:raises: BarcodeSizeError, BarcodeTypeError, BarcodeCodeError
"""
# Align Bar Code()
self._raw(TXT_ALIGN_CT)
# Height
@ -225,14 +272,27 @@ class Escpos(object):
raise BarcodeCodeError()
def text(self, txt):
""" Print alpha-numeric text """
""" Print alpha-numeric text
The text has to be encoded in the currently selected codepage.
:param txt: text to be printed
:raises: TextError
"""
if txt:
self._raw(txt)
else:
raise TextError()
def set(self, align='left', font='a', text_type='normal', width=1, height=1, density=9):
""" Set text properties """
""" Set text properties by sending them to the printer
:param align: alignment of text
:param font: font A or B
:param text_type: add bold or underlined
:param width: text width, normal or double width
:param height: text height, normal or double height
:param density: print density
"""
# Width
if height == 2 and width == 2:
self._raw(TXT_NORMAL)
@ -299,7 +359,10 @@ class Escpos(object):
pass
def cut(self, mode=''):
""" Cut paper """
""" Cut paper
:param mode: set to 'PART' for a partial cut
"""
# Fix the size between last line and cut
# TODO: handle this with a line feed
self._raw("\n\n\n\n\n\n")
@ -309,7 +372,12 @@ class Escpos(object):
self._raw(PAPER_FULL_CUT)
def cashdraw(self, pin):
""" Send pulse to kick the cash drawer """
""" Send pulse to kick the cash drawer
Kick cash drawer on pin 2 or pin 5.
:param pin: pin number
:raises: CashDrawerError
"""
if pin == 2:
self._raw(CD_KICK_2)
elif pin == 5:
@ -318,7 +386,10 @@ class Escpos(object):
raise CashDrawerError()
def hw(self, hw):
""" Hardware operations """
""" Hardware operations
:param hw: hardware action
"""
if hw.upper() == "INIT":
self._raw(HW_INIT)
elif hw.upper() == "SELECT":
@ -329,10 +400,13 @@ class Escpos(object):
pass
def control(self, ctl, pos=4):
""" Feed control sequences """
""" Feed control sequences
:raises: TabPosError
"""
# Set tab positions
if pos < 1 or pos > 16:
raise TabError()
raise TabPosError()
else:
self._raw("".join([CTL_SET_HT, hex(pos)]))
# Set position

10
escpos/exceptions.py
View File

@ -26,6 +26,7 @@ class Error(Exception):
class BarcodeTypeError(Error):
"""No Barcode type defined """
def __init__(self, msg=""):
Error.__init__(self, msg)
self.msg = msg
@ -36,6 +37,7 @@ class BarcodeTypeError(Error):
class BarcodeSizeError(Error):
""" Barcode size is out of range """
def __init__(self, msg=""):
Error.__init__(self, msg)
self.msg = msg
@ -46,16 +48,18 @@ class BarcodeSizeError(Error):
class BarcodeCodeError(Error):
""" No Barcode code was supplied """
def __init__(self, msg=""):
Error.__init__(self, msg)
self.msg = msg
self.resultcode = 30
def __str__(self):
return "Code was not supplied"
return "No Barcode code was supplied"
class ImageSizeError(Error):
""" Image height is longer than 255px and can't be printed """
def __init__(self, msg=""):
Error.__init__(self, msg)
self.msg = msg
@ -66,6 +70,7 @@ class ImageSizeError(Error):
class TextError(Error):
""" Test sting must be supplied to the text() method """
def __init__(self, msg=""):
Error.__init__(self, msg)
self.msg = msg
@ -76,6 +81,7 @@ class TextError(Error):
class CashDrawerError(Error):
""" Valid pin must be set to send pulse """
def __init__(self, msg=""):
Error.__init__(self, msg)
self.msg = msg
@ -86,6 +92,7 @@ class CashDrawerError(Error):
class TabPosError(Error):
""" Valid tab positions must be in the range 0 to 16 """
def __init__(self, msg=""):
Error.__init__(self, msg)
self.msg = msg
@ -96,6 +103,7 @@ class TabPosError(Error):
class CharCodeError(Error):
""" Valid char code must be set """
def __init__(self, msg=""):
Error.__init__(self, msg)
self.msg = msg

12
escpos/printer.py
View File

@ -20,11 +20,11 @@ class Usb(Escpos):
def __init__(self, idVendor, idProduct, interface=0, in_ep=0x82, out_ep=0x01):
"""
@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
: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
"""
self.idVendor = idVendor
self.idProduct = idProduct
@ -34,7 +34,7 @@ class Usb(Escpos):
self.open()
def open(self):
""" Search device on USB tree and set is as escpos device """
""" 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:
print "Cable isn't plugged in"