File: utils.py

package info (click to toggle)
domdf-python-tools 3.10.0-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 1,784 kB
  • sloc: python: 10,838; makefile: 7
file content (126 lines) | stat: -rw-r--r-- 3,585 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
#  !/usr/bin/env python
#
#  utils.py
"""
Tools for working with pagesizes.
"""
#
#  Copyright © 2020 Dominic Davis-Foster <dominic@davis-foster.co.uk>
#
#  Based on reportlab.lib.pagesizes and reportlab.lib.units
#    www.reportlab.co.uk
#    Copyright ReportLab Europe Ltd. 2000-2017
#    Copyright (c) 2000-2018, ReportLab Inc.
#    All rights reserved.
#    Licensed under the BSD License
#
#  Includes data from en.wikipedia.org.
#  Licensed under the Creative Commons Attribution-ShareAlike License
#
#  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.
#

# stdlib
import re
from typing import Sequence, Tuple, Union, overload

# this package
from domdf_python_tools.typing import AnyNumber

# this package
from .units import Unit, cm, inch, mm, pc, pt, um

# from .units import Unit

__all__ = ["convert_from", "parse_measurement"]


@overload
def convert_from(value: Sequence[AnyNumber], from_: AnyNumber) -> Tuple[float, ...]: ...


@overload
def convert_from(value: AnyNumber, from_: AnyNumber) -> float: ...


def convert_from(
		value: Union[Sequence[AnyNumber], AnyNumber],
		from_: AnyNumber,
		) -> Union[float, Tuple[float, ...]]:
	r"""
	Convert ``value`` to point from the unit specified in ``from_``.

	:param value:
	:param from\_: The unit to convert from, specified as a number of points.
	"""

	if isinstance(value, Sequence):
		return _sequence_convert_from(value, from_)
	else:
		return _sequence_convert_from((value, ), from_)[0]


def _sequence_convert_from(seq: Sequence[AnyNumber], from_: AnyNumber) -> Tuple[float, ...]:
	if isinstance(from_, Unit):
		from_ = from_._in_pt
	else:
		from_ = float(from_)

	return tuple(float(x) * from_ for x in seq)


_measurement_re = re.compile(r"(\d*\.?\d+) *([A-Za-zμµ\"']*)")


def parse_measurement(measurement: str) -> Union[float, Tuple[float, ...]]:
	"""
	Parse the given measurement.

	:param measurement:
	"""

	# TODO: docstring
	all_matches = _measurement_re.findall(measurement)

	if len(all_matches) > 1:
		raise ValueError("Too many measurements")
	elif len(all_matches) == 0:
		raise ValueError("Unable to parse measurement")

	val, unit = all_matches[0]

	if '' in {val, unit}:
		raise ValueError("Unable to parse measurement")

	val = float(val)

	if unit == "mm":
		return val * mm
	elif unit == "cm":
		return val * cm
	elif unit in {"um", "μm", "µm"}:  # second is mu, third is micro
		return val * um
	elif unit == "pt":
		return val * pt
	elif unit in {"inch", "in", '"'}:
		return val * inch
	elif unit in ("pc", "pica"):
		return val * pc

	raise ValueError("Unknown unit")