Start on a command-line interface to the library (still hard-codes USB ID)

(...and still needs better documentation)

escpos/cli.py

@@ -0,0 +1,200 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+"""A simple command-line interface for common python-escpos functionality
+
+Usage: python -m escpos.cli --help
+
+Dependencies:
+- DavisGoglin/python-escpos or better
+- A file named weather.png (for the 'test' subcommand)
+
+Reasons for using the DavisGoglin/python-escpos fork:
+- image() accepts a PIL.Image object rather than requiring me to choose
+  between writing a temporary file to disk or calling a "private" method.
+- fullimage() allows me to print images of arbitrary length using slicing.
+
+How to print unsupported barcodes:
+    barcode -b 'BARCODE' -e 'code39' -E | convert -density 200% eps:- code.png
+    python test_escpos.py --images code.png
+
+Copyright (C) 2014 Stephan Sokolow (deitarion/SSokolow)
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
+OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+"""
+
+from __future__ import absolute_import
+
+__author__ = "Stephan Sokolow (deitarion/SSokolow)"
+__license__ = "MIT"
+
+import re
+
+from escpos import printer
+epson = printer.Usb(0x0416, 0x5011)
+# TODO: Un-hardcode this
+
+def _print_text_file(path):
+    """Print the given text file"""
+    epson.set(align='left')
+    with open(path, 'rU') as fobj:
+        for line in fobj:
+            epson.text(line)
+
+def _print_image_file(path):
+    """Print the given image file."""
+    epson.fullimage(path, histeq=False, width=384)
+
+def print_files(args):
+    """The 'print' subcommand"""
+    for path in args.paths:
+        if args.images:
+            _print_image_file(path)
+        else:
+            _print_text_file(path)
+    epson.cut()
+
+# {{{ 'echo' Subcommand
+
+KNOWN_BARCODE_TYPES = ['UPC-A', 'UPC-E', 'EAN13', 'ITF']
+re_barcode_escape = re.compile(r'^%(?P<type>\S+)\s(?P<data>[0-9X]+)$')
+
+def echo(args):  # pylint: disable=unused-argument
+    """TTY-like line-by-line keyboard-to-printer echo loop."""
+    try:
+        while True:
+            line = raw_input()
+            match = re_barcode_escape.match(line)
+            if match and match.group('type') in KNOWN_BARCODE_TYPES:
+                bctype, data = match.groups()
+                epson.barcode(data, bctype, 48, 2, '', '')
+                epson.set(align='left')
+            else:
+                epson.text('%s\n' % line)
+    except KeyboardInterrupt:
+        epson.cut()
+
+# }}}
+# {{{ 'test' Subcommand
+
+from PIL import Image, ImageDraw
+
+def _stall_test(width, height):
+    """Generate a pattern to detect print glitches due to vertical stalling."""
+    img = Image.new('1', (width, height))
+    for pos in [(x, y) for y in range(0, height) for x in range(0, width)]:
+        img.putpixel(pos, not sum(pos) % 10)
+    return img
+
+def _test_basic():
+    """The original test code from python-escpos's Usage wiki page"""
+    epson.set(align='left')
+    # Print text
+    epson.text("TODO:\n")  # pylint: disable=fixme
+    epson.text("[ ] Task 1\n")
+    epson.text("[ ] Task 2\n")
+    # Print image
+    # TODO: Bundle an image so this can be used
+    # epson.image("weather.png")
+    # Print QR Code (must have a white border to be scanned)
+    epson.set(align='center')
+    epson.text("Scan to recall TODO list")  # pylint: disable=fixme
+    epson.qr("http://www.example.com/")
+    # Print barcode
+    epson.barcode('1234567890128', 'EAN13', 32, 2, '', '')
+    # Cut paper
+    epson.cut()
+
+def _test_barcodes():
+    """Print test barcodes for all ESCPOS-specified formats."""
+    for name, data in (
+        # pylint: disable=bad-continuation
+        ('UPC-A', '123456789012\x00'),
+        ('UPC-E', '02345036\x00'),
+        ('EAN13', '1234567890128\x00'),
+        ('EAN8', '12345670\x00'),
+        ('CODE39', 'BARCODE12345678\x00'),
+        ('ITF', '123456\x00'),
+        ('CODABAR', 'A40156B'),
+        # TODO: CODE93 and CODE128
+    ):
+        # TODO: Fix the library to restore old alignment somehow
+        epson.set(align='center')
+        epson.text('\n%s\n' % name)
+        epson.barcode(data, name, 64, 2, '', '')
+
+def _test_patterns(width=384, height=255):
+    """Print a set of test patterns for raster image output."""
+    # Test our guess of the paper width
+    img = Image.new('1', (width, height), color=1)
+    draw = ImageDraw.Draw(img)
+    draw.polygon(((0, 0), img.size, (0, img.size[1])), fill=0)
+    epson.image(img)
+    del draw, img
+
+    # Test the consistency of printing large data and whether stall rate is
+    # affected by data rate
+    epson.image(_stall_test(width, height))
+    epson.image(_stall_test(width / 2, height))
+
+def test(args):
+    """The 'test' subcommand"""
+    if args.barcodes:
+        _test_barcodes()
+    elif args.patterns:
+        _test_patterns()
+    else:
+        _test_basic()
+
+# }}}
+
+def main():
+    """Wrapped in a function for import and entry point compatibility"""
+    # pylint: disable=bad-continuation
+
+    import argparse
+    parser = argparse.ArgumentParser(
+        description="Command-line interface to python-escpos")
+    subparsers = parser.add_subparsers(title='subcommands')
+
+    echo_parser = subparsers.add_parser('echo', help='Echo the keyboard to '
+        'the printer line-by-line (Exit with Ctrl+C)')
+    echo_parser.set_defaults(func=echo)
+
+    print_parser = subparsers.add_parser('print', help='Print the given files')
+    print_parser.add_argument('--images', action='store_true',
+        help="Provided files are images rather than text files.")
+    print_parser.add_argument('paths', metavar='path', nargs='+')
+    print_parser.set_defaults(func=print_files)
+
+    test_parser = subparsers.add_parser('test', help='Print test patterns')
+    test_modes = test_parser.add_mutually_exclusive_group()
+    test_modes.add_argument('--barcodes', action='store_true',
+        help="Test supported barcode types (Warning: Some printers must be "
+        "reset after attempting an unsupported barcode type.)")
+    test_modes.add_argument('--patterns', action='store_true',
+                            help="Print test patterns")
+    test_parser.set_defaults(func=test)
+
+    args = parser.parse_args()
+    args.func(args)
+
+if __name__ == '__main__':
+    main()
+
+# vim: set sw=4 sts=4 :