'''
Parser utilities
================
Helper functions used for CSS parsing.
'''
__all__ = ('parse_color', 'parse_int', 'parse_float',
'parse_string', 'parse_bool', 'parse_int2',
'parse_float4', 'parse_filename')
import re
from kivy.logger import Logger
from kivy.resources import resource_find
class ColorException(Exception):
pass
[docs]def parse_filename(filename):
'''Parse a filename and search for it using `resource_find()`.
If found, the resource path is returned, otherwise return the unmodified
filename (as specified by the caller).'''
filename = parse_string(filename)
result = resource_find(filename)
if result is None:
Logger.error('Resource: unable to find <%s>' % filename)
return result or filename
def color_error(text):
# show warning and return a sane value
Logger.warning(text)
return (0, 0, 0, 1)
[docs]def parse_color(text):
'''Parse a string to a kivy color. Supported formats:
* rgb(r, g, b)
* rgba(r, g, b, a)
* rgb
* rgba
* rrggbb
* rrggbbaa
For hexadecimal values, you case also use:
* #rgb
* #rgba
* #rrggbb
* #rrggbbaa
'''
value = [1, 1, 1, 1]
if text.startswith('rgb'):
res = re.match('rgba?\((.*)\)', text)
if res:
try:
# default r/g/b values to 1 if greater than 255 else x/255
value = [1 if int(x) > 255. else (int(x) / 255.)
for x in re.split(',\ ?', res.groups()[0])]
if len(value) < 3:
# in case of invalid input like rgb()/rgb(r)/rgb(r, g)
raise ValueError
except ValueError:
return color_error('ColorParser: Invalid color for %r' % text)
except AttributeError:
return color_error('ColorParser: Invalid color for %r' % text)
else:
return color_error('ColorParser: Invalid color for %r' % text)
if len(value) == 3:
value.append(1.)
elif len(text):
res = text
if text[0] == '#':
res = text[1:]
lres = len(res)
if lres == 3 or lres == 4:
res = ''.join([x + x for x in res])
elif lres != 6 and lres != 8:
# raise ColorException('Invalid color format for %r' % text)
return color_error(
'ColorParser: Invalid color format for %r' % text)
try:
value = [int(res[i:i + 2], 16) / 255.
for i in range(0, len(res), 2)]
except ValueError:
return color_error('ColorParser: Invalid color for %r' % text)
if lres == 6 or lres == 3:
value.append(1.)
return value
[docs]def parse_bool(text):
'''Parse a string to a boolean, ignoring case. "true"/"1" is True,
"false"/"0" is False. Anything else throws an exception.'''
if text.lower() in ('true', '1'):
return True
elif text.lower() in ('false', '0'):
return False
raise Exception('Invalid boolean: %s' % text)
[docs]def parse_string(text):
'''Parse a string to a string (removing single and double quotes).'''
if len(text) >= 2 and text[0] in ('"', "'") and text[-1] in ('"', "'"):
text = text[1:-1]
return text.strip()
[docs]def parse_int2(text):
'''Parse a string to a list of exactly 2 integers.
>>> print(parse_int2("12 54"))
12, 54
'''
texts = [x for x in text.split(' ') if x.strip() != '']
value = list(map(parse_int, texts))
if len(value) < 1:
raise Exception('Invalid int2 format: %s' % text)
elif len(value) == 1:
return [value[0], value[0]]
elif len(value) > 2:
raise Exception('Too many values in %s: %s' % (text, str(value)))
return value
[docs]def parse_float4(text):
'''Parse a string to a list of exactly 4 floats.
>>> parse_float4('54 87. 35 0')
54, 87., 35, 0
'''
texts = [x for x in text.split(' ') if x.strip() != '']
value = list(map(parse_float, texts))
if len(value) < 1:
raise Exception('Invalid float4 format: %s' % text)
elif len(value) == 1:
return [value[0] for x in range(4)]
elif len(value) == 2:
return [value[0], value[1], value[0], value[1]]
elif len(value) == 3:
# ambiguous case!
return [value[0], value[1], value[0], value[2]]
elif len(value) > 4:
raise Exception('Too many values in %s' % text)
return value
parse_int = int
parse_float = float
