SP/web2py/gluon/contrib/minify/cssmin.py
Saturneic 064f602b1a Add.
2018-10-25 23:33:13 +08:00

235 lines
6.8 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""`cssmin` - A Python port of the YUI CSS compressor."""
"""
Home page: https://github.com/zacharyvoase/cssmin
License: BSD: https://github.com/zacharyvoase/cssmin/blob/master/LICENSE
Original author: Zachary Voase
Modified for inclusion into web2py by: Ross Peoples <ross.peoples@gmail.com>
"""
try:
from StringIO import StringIO
except ImportError:
from io import StringIO
import re
__version__ = '0.1.4'
def remove_comments(css):
"""Remove all CSS comment blocks."""
iemac = False
preserve = False
comment_start = css.find("/*")
while comment_start >= 0:
# Preserve comments that look like `/*!...*/`.
# Slicing is used to make sure we don"t get an IndexError.
preserve = css[comment_start + 2:comment_start + 3] == "!"
comment_end = css.find("*/", comment_start + 2)
if comment_end < 0:
if not preserve:
css = css[:comment_start]
break
elif comment_end >= (comment_start + 2):
if css[comment_end - 1] == "\\":
# This is an IE Mac-specific comment; leave this one and the
# following one alone.
comment_start = comment_end + 2
iemac = True
elif iemac:
comment_start = comment_end + 2
iemac = False
elif not preserve:
css = css[:comment_start] + css[comment_end + 2:]
else:
comment_start = comment_end + 2
comment_start = css.find("/*", comment_start)
return css
def remove_unnecessary_whitespace(css):
"""Remove unnecessary whitespace characters."""
def pseudoclasscolon(css):
"""
Prevents 'p :link' from becoming 'p:link'.
Translates 'p :link' into 'p ___PSEUDOCLASSCOLON___link'; this is
translated back again later.
"""
regex = re.compile(r"(^|\})(([^\{\:])+\:)+([^\{]*\{)")
match = regex.search(css)
while match:
css = ''.join([
css[:match.start()],
match.group().replace(":", "___PSEUDOCLASSCOLON___"),
css[match.end():]])
match = regex.search(css)
return css
css = pseudoclasscolon(css)
# Remove spaces from before things.
css = re.sub(r"\s+([!{};:>+\(\)\],])", r"\1", css)
# If there is a `@charset`, then only allow one, and move to the beginning.
css = re.sub(r"^(.*)(@charset \"[^\"]*\";)", r"\2\1", css)
css = re.sub(r"^(\s*@charset [^;]+;\s*)+", r"\1", css)
# Put the space back in for a few cases, such as `@media screen` and
# `(-webkit-min-device-pixel-ratio:0)`.
css = re.sub(r"\band\(", "and (", css)
# Put the colons back.
css = css.replace('___PSEUDOCLASSCOLON___', ':')
# Remove spaces from after things.
css = re.sub(r"([!{}:;>+\(\[,])\s+", r"\1", css)
return css
def remove_unnecessary_semicolons(css):
"""Remove unnecessary semicolons."""
return re.sub(r";+\}", "}", css)
def remove_empty_rules(css):
"""Remove empty rules."""
return re.sub(r"[^\}\{]+\{\}", "", css)
def normalize_rgb_colors_to_hex(css):
"""Convert `rgb(51,102,153)` to `#336699`."""
regex = re.compile(r"rgb\s*\(\s*([0-9,\s]+)\s*\)")
match = regex.search(css)
while match:
colors = map(lambda s: s.strip(), match.group(1).split(","))
hexcolor = '#%.2x%.2x%.2x' % tuple(map(int, colors))
css = css.replace(match.group(), hexcolor)
match = regex.search(css)
return css
def condense_zero_units(css):
"""Replace `0(px, em, %, etc)` with `0`."""
return re.sub(r"([\s:])(0)(px|em|%|in|cm|mm|pc|pt|ex)", r"\1\2", css)
def condense_multidimensional_zeros(css):
"""Replace `:0 0 0 0;`, `:0 0 0;` etc. with `:0;`."""
css = css.replace(":0 0 0 0;", ":0;")
css = css.replace(":0 0 0;", ":0;")
css = css.replace(":0 0;", ":0;")
# Revert `background-position:0;` to the valid `background-position:0 0;`.
css = css.replace("background-position:0;", "background-position:0 0;")
return css
def condense_floating_points(css):
"""Replace `0.6` with `.6` where possible."""
return re.sub(r"(:|\s)0+\.(\d+)", r"\1.\2", css)
def condense_hex_colors(css):
"""Shorten colors from #AABBCC to #ABC where possible."""
regex = re.compile(r"([^\"'=\s])(\s*)#([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])")
match = regex.search(css)
while match:
first = match.group(3) + match.group(5) + match.group(7)
second = match.group(4) + match.group(6) + match.group(8)
if first.lower() == second.lower():
css = css.replace(
match.group(), match.group(1) + match.group(2) + '#' + first)
match = regex.search(css, match.end() - 3)
else:
match = regex.search(css, match.end())
return css
def condense_whitespace(css):
"""Condense multiple adjacent whitespace characters into one."""
return re.sub(r"\s+", " ", css)
def condense_semicolons(css):
"""Condense multiple adjacent semicolon characters into one."""
return re.sub(r";;+", ";", css)
def wrap_css_lines(css, line_length):
"""Wrap the lines of the given CSS to an approximate length."""
lines = []
line_start = 0
for i, char in enumerate(css):
# It's safe to break after `}` characters.
if char == '}' and (i - line_start >= line_length):
lines.append(css[line_start:i + 1])
line_start = i + 1
if line_start < len(css):
lines.append(css[line_start:])
return '\n'.join(lines)
def cssmin(css, wrap=None):
css = remove_comments(css)
css = condense_whitespace(css)
# A pseudo class for the Box Model Hack
# (see http://tantek.com/CSS/Examples/boxmodelhack.html)
css = css.replace('"\\"}\\""', "___PSEUDOCLASSBMH___")
css = remove_unnecessary_whitespace(css)
css = remove_unnecessary_semicolons(css)
css = condense_zero_units(css)
css = condense_multidimensional_zeros(css)
css = condense_floating_points(css)
css = normalize_rgb_colors_to_hex(css)
css = condense_hex_colors(css)
if wrap is not None:
css = wrap_css_lines(css, wrap)
css = css.replace("___PSEUDOCLASSBMH___", '"\\"}\\""')
css = condense_semicolons(css)
return css.strip()
def main():
import optparse
import sys
p = optparse.OptionParser(
prog="cssmin", version=__version__,
usage="%prog [--wrap N]",
description="""Reads raw CSS from stdin, and writes compressed CSS to stdout.""")
p.add_option(
'-w', '--wrap', type='int', default=None, metavar='N',
help="Wrap output to approximately N chars per line.")
options, args = p.parse_args()
sys.stdout.write(cssmin(sys.stdin.read(), wrap=options.wrap))
if __name__ == '__main__':
main()