# pylint: disable=W0611
'''
Utils
=====
The Utils module provides a selection of general utility functions and classes
that may be useful for various applications. These include maths, color,
algebraic and platform functions.
.. versionchanged:: 1.6.0
The OrderedDict class has been removed. Use collections.OrderedDict
instead.
'''
__all__ = ('intersection', 'difference', 'strtotuple',
'get_color_from_hex', 'get_hex_from_color', 'get_random_color',
'is_color_transparent', 'hex_colormap', 'colormap', 'boundary',
'deprecated', 'SafeList',
'interpolate', 'QueryDict',
'platform', 'escape_markup', 'reify', 'rgba')
from os import environ
from sys import platform as _sys_platform
from re import match, split
from kivy.compat import string_types
[docs]def boundary(value, minvalue, maxvalue):
'''Limit a value between a minvalue and maxvalue.'''
return min(max(value, minvalue), maxvalue)
[docs]def intersection(set1, set2):
'''Return the intersection of 2 lists.'''
return [s for s in set1 if s in set2]
[docs]def difference(set1, set2):
'''Return the difference between 2 lists.'''
return [s for s in set1 if s not in set2]
[docs]def interpolate(value_from, value_to, step=10):
'''Interpolate between two values. This can be useful for smoothing some
transitions. For example::
# instead of setting directly
self.pos = pos
# use interpolate, and you'll have a nicer transition
self.pos = interpolate(self.pos, new_pos)
.. warning::
These interpolations work only on lists/tuples/doubles with the same
dimensions. No test is done to check the dimensions are the same.
'''
if type(value_from) in (list, tuple):
out = []
for x, y in zip(value_from, value_to):
out.append(interpolate(x, y, step))
return out
else:
return value_from + (value_to - value_from) / float(step)
[docs]def strtotuple(s):
'''Convert a tuple string into a tuple
with some security checks. Designed to be used
with the eval() function::
a = (12, 54, 68)
b = str(a) # return '(12, 54, 68)'
c = strtotuple(b) # return (12, 54, 68)
'''
# security
if not match('^[,.0-9 ()\[\]]*$', s):
raise Exception('Invalid characters in string for tuple conversion')
# fast syntax check
if s.count('(') != s.count(')'):
raise Exception('Invalid count of ( and )')
if s.count('[') != s.count(']'):
raise Exception('Invalid count of [ and ]')
r = eval(s)
if type(r) not in (list, tuple):
raise Exception('Conversion failed')
return r
[docs]def rgba(s, *args):
'''Return a Kivy color (4 value from 0-1 range) from either a hex string or
a list of 0-255 values.
.. versionadded:: 1.10.0
'''
if isinstance(s, string_types):
return get_color_from_hex(s)
elif isinstance(s, (list, tuple)):
s = map(lambda x: x / 255., s)
if len(s) == 3:
return list(s) + [1]
return s
elif isinstance(s, (int, float)):
s = map(lambda x: x / 255., [s] + list(args))
if len(s) == 3:
return list(s) + [1]
return s
raise Exception('Invalid value (not a string / list / tuple)')
[docs]def get_color_from_hex(s):
'''Transform a hex string color to a kivy
:class:`~kivy.graphics.Color`.
'''
if s.startswith('#'):
return get_color_from_hex(s[1:])
value = [int(x, 16) / 255.
for x in split('([0-9a-f]{2})', s.lower()) if x != '']
if len(value) == 3:
value.append(1)
return value
[docs]def get_hex_from_color(color):
'''Transform a kivy :class:`~kivy.graphics.Color` to a hex value::
>>> get_hex_from_color((0, 1, 0))
'#00ff00'
>>> get_hex_from_color((.25, .77, .90, .5))
'#3fc4e57f'
.. versionadded:: 1.5.0
'''
return '#' + ''.join(['{0:02x}'.format(int(x * 255)) for x in color])
[docs]def get_random_color(alpha=1.0):
'''Returns a random color (4 tuple).
:Parameters:
`alpha`: float, defaults to 1.0
If alpha == 'random', a random alpha value is generated.
'''
from random import random
if alpha == 'random':
return [random(), random(), random(), random()]
else:
return [random(), random(), random(), alpha]
[docs]def is_color_transparent(c):
'''Return True if the alpha channel is 0.'''
if len(c) < 4:
return False
if float(c[3]) == 0.:
return True
return False
hex_colormap = {
'aliceblue': '#f0f8ff',
'antiquewhite': '#faebd7',
'aqua': '#00ffff',
'aquamarine': '#7fffd4',
'azure': '#f0ffff',
'beige': '#f5f5dc',
'bisque': '#ffe4c4',
'black': '#000000',
'blanchedalmond': '#ffebcd',
'blue': '#0000ff',
'blueviolet': '#8a2be2',
'brown': '#a52a2a',
'burlywood': '#deb887',
'cadetblue': '#5f9ea0',
'chartreuse': '#7fff00',
'chocolate': '#d2691e',
'coral': '#ff7f50',
'cornflowerblue': '#6495ed',
'cornsilk': '#fff8dc',
'crimson': '#dc143c',
'cyan': '#00ffff',
'darkblue': '#00008b',
'darkcyan': '#008b8b',
'darkgoldenrod': '#b8860b',
'darkgray': '#a9a9a9',
'darkgrey': '#a9a9a9',
'darkgreen': '#006400',
'darkkhaki': '#bdb76b',
'darkmagenta': '#8b008b',
'darkolivegreen': '#556b2f',
'darkorange': '#ff8c00',
'darkorchid': '#9932cc',
'darkred': '#8b0000',
'darksalmon': '#e9967a',
'darkseagreen': '#8fbc8f',
'darkslateblue': '#483d8b',
'darkslategray': '#2f4f4f',
'darkslategrey': '#2f4f4f',
'darkturquoise': '#00ced1',
'darkviolet': '#9400d3',
'deeppink': '#ff1493',
'deepskyblue': '#00bfff',
'dimgray': '#696969',
'dimgrey': '#696969',
'dodgerblue': '#1e90ff',
'firebrick': '#b22222',
'floralwhite': '#fffaf0',
'forestgreen': '#228b22',
'fuchsia': '#ff00ff',
'gainsboro': '#dcdcdc',
'ghostwhite': '#f8f8ff',
'gold': '#ffd700',
'goldenrod': '#daa520',
'gray': '#808080',
'grey': '#808080',
'green': '#008000',
'greenyellow': '#adff2f',
'honeydew': '#f0fff0',
'hotpink': '#ff69b4',
'indianred': '#cd5c5c',
'indigo': '#4b0082',
'ivory': '#fffff0',
'khaki': '#f0e68c',
'lavender': '#e6e6fa',
'lavenderblush': '#fff0f5',
'lawngreen': '#7cfc00',
'lemonchiffon': '#fffacd',
'lightblue': '#add8e6',
'lightcoral': '#f08080',
'lightcyan': '#e0ffff',
'lightgoldenrodyellow': '#fafad2',
'lightgreen': '#90ee90',
'lightgray': '#d3d3d3',
'lightgrey': '#d3d3d3',
'lightpink': '#ffb6c1',
'lightsalmon': '#ffa07a',
'lightseagreen': '#20b2aa',
'lightskyblue': '#87cefa',
'lightslategray': '#778899',
'lightslategrey': '#778899',
'lightsteelblue': '#b0c4de',
'lightyellow': '#ffffe0',
'lime': '#00ff00',
'limegreen': '#32cd32',
'linen': '#faf0e6',
'magenta': '#ff00ff',
'maroon': '#800000',
'mediumaquamarine': '#66cdaa',
'mediumblue': '#0000cd',
'mediumorchid': '#ba55d3',
'mediumpurple': '#9370db',
'mediumseagreen': '#3cb371',
'mediumslateblue': '#7b68ee',
'mediumspringgreen': '#00fa9a',
'mediumturquoise': '#48d1cc',
'mediumvioletred': '#c71585',
'midnightblue': '#191970',
'mintcream': '#f5fffa',
'mistyrose': '#ffe4e1',
'moccasin': '#ffe4b5',
'navajowhite': '#ffdead',
'navy': '#000080',
'oldlace': '#fdf5e6',
'olive': '#808000',
'olivedrab': '#6b8e23',
'orange': '#ffa500',
'orangered': '#ff4500',
'orchid': '#da70d6',
'palegoldenrod': '#eee8aa',
'palegreen': '#98fb98',
'paleturquoise': '#afeeee',
'palevioletred': '#db7093',
'papayawhip': '#ffefd5',
'peachpuff': '#ffdab9',
'peru': '#cd853f',
'pink': '#ffc0cb',
'plum': '#dda0dd',
'powderblue': '#b0e0e6',
'purple': '#800080',
'red': '#ff0000',
'rosybrown': '#bc8f8f',
'royalblue': '#4169e1',
'saddlebrown': '#8b4513',
'salmon': '#fa8072',
'sandybrown': '#f4a460',
'seagreen': '#2e8b57',
'seashell': '#fff5ee',
'sienna': '#a0522d',
'silver': '#c0c0c0',
'skyblue': '#87ceeb',
'slateblue': '#6a5acd',
'slategray': '#708090',
'slategrey': '#708090',
'snow': '#fffafa',
'springgreen': '#00ff7f',
'steelblue': '#4682b4',
'tan': '#d2b48c',
'teal': '#008080',
'thistle': '#d8bfd8',
'tomato': '#ff6347',
'turquoise': '#40e0d0',
'violet': '#ee82ee',
'wheat': '#f5deb3',
'white': '#ffffff',
'whitesmoke': '#f5f5f5',
'yellow': '#ffff00',
'yellowgreen': '#9acd32',
}
colormap = {k: get_color_from_hex(v) for k, v in hex_colormap.items()}
DEPRECATED_CALLERS = []
[docs]def deprecated(func):
'''This is a decorator which can be used to mark functions
as deprecated. It will result in a warning being emitted the first time
the function is used.'''
import inspect
import functools
@functools.wraps(func)
def new_func(*args, **kwargs):
file, line, caller = inspect.stack()[1][1:4]
caller_id = "%s:%s:%s" % (file, line, caller)
# We want to print deprecated warnings only once:
if caller_id not in DEPRECATED_CALLERS:
DEPRECATED_CALLERS.append(caller_id)
warning = (
'Call to deprecated function %s in %s line %d.'
'Called from %s line %d'
' by %s().' % (
func.__name__,
func.__code__.co_filename,
func.__code__.co_firstlineno + 1,
file, line, caller))
from kivy.logger import Logger
Logger.warn(warning)
if func.__doc__:
Logger.warn(func.__doc__)
return func(*args, **kwargs)
return new_func
[docs]class SafeList(list):
'''List with a clear() method.
.. warning::
Usage of the iterate() function will decrease your performance.
'''
[docs] def clear(self):
del self[:]
@deprecated
def iterate(self, reverse=False):
if reverse:
return iter(reversed(self))
return iter(self)
[docs]class QueryDict(dict):
'''QueryDict is a dict() that can be queried with dot.
::
d = QueryDict()
# create a key named toto, with the value 1
d.toto = 1
# it's the same as
d['toto'] = 1
.. versionadded:: 1.0.4
'''
def __getattr__(self, attr):
try:
return self.__getitem__(attr)
except KeyError:
return super(QueryDict, self).__getattr__(attr)
def __setattr__(self, attr, value):
self.__setitem__(attr, value)
def format_bytes_to_human(size, precision=2):
'''Format a byte value to a human readable representation (B, KB, MB...).
.. versionadded:: 1.0.8
:Parameters:
`size`: int
Number that represents the bytes value
`precision`: int, defaults to 2
Precision after the comma
Examples::
>>> format_bytes_to_human(6463)
'6.31 KB'
>>> format_bytes_to_human(646368746541)
'601.98 GB'
'''
size = int(size)
fmt = '%%1.%df %%s' % precision
for unit in ['B', 'KB', 'MB', 'GB', 'TB']:
if size < 1024.0:
return fmt % (size, unit)
size /= 1024.0
def _get_platform():
# On Android sys.platform returns 'linux2', so prefer to check the
# presence of python-for-android environment variables (ANDROID_ARGUMENT
# or ANDROID_PRIVATE).
if 'ANDROID_ARGUMENT' in environ:
return 'android'
elif environ.get('KIVY_BUILD', '') == 'ios':
return 'ios'
elif _sys_platform in ('win32', 'cygwin'):
return 'win'
elif _sys_platform == 'darwin':
return 'macosx'
elif _sys_platform.startswith('linux'):
return 'linux'
elif _sys_platform.startswith('freebsd'):
return 'linux'
return 'unknown'
platform = _get_platform()
'''
A string identifying the current operating system. It is one
of: `'win'`, `'linux'`, `'android'`, `'macosx'`, `'ios'` or `'unknown'`.
You can use it as follows::
from kivy.utils import platform
if platform == 'linux':
do_linux_things()
.. versionadded:: 1.3.0
.. versionchanged:: 1.8.0
platform is now a variable instead of a function.
'''
[docs]def escape_markup(text):
'''
Escape markup characters found in the text. Intended to be used when markup
text is activated on the Label::
untrusted_text = escape_markup('Look at the example [1]')
text = '[color=ff0000]' + untrusted_text + '[/color]'
w = Label(text=text, markup=True)
.. versionadded:: 1.3.0
'''
return text.replace('&', '&').replace('[', '&bl;').replace(']', '&br;')
[docs]class reify(object):
'''
Put the result of a method which uses this (non-data) descriptor decorator
in the instance dict after the first call, effectively replacing the
decorator with an instance variable.
It acts like @property, except that the function is only ever called once;
after that, the value is cached as a regular attribute. This gives you lazy
attribute creation on objects that are meant to be immutable.
Taken from the `Pyramid project <https://pypi.python.org/pypi/pyramid/>`_.
To use this as a decorator::
@reify
def lazy(self):
...
return hard_to_compute_int
first_time = self.lazy # lazy is reify obj, reify.__get__() runs
second_time = self.lazy # lazy is hard_to_compute_int
'''
def __init__(self, func):
self.func = func
self.__doc__ = func.__doc__
def __get__(self, inst, cls):
if inst is None:
return self
retval = self.func(inst)
setattr(inst, self.func.__name__, retval)
return retval
