fontchain_lint.py revision 0e969e2c0ba9ad863c7fcfc3973a16b1b599e50a 
1#!/usr/bin/env python
2
3import collections
4import glob
5from os import path
6import sys
7from xml.etree import ElementTree
8
9from fontTools import ttLib
10
11LANG_TO_SCRIPT = {
12    'de': 'Latn',
13    'en': 'Latn',
14    'es': 'Latn',
15    'eu': 'Latn',
16    'ja': 'Jpan',
17    'ko': 'Kore',
18    'hu': 'Latn',
19    'hy': 'Armn',
20    'nb': 'Latn',
21    'nn': 'Latn',
22    'pt': 'Latn',
23}
24
25def lang_to_script(lang_code):
26    lang = lang_code.lower()
27    while lang not in LANG_TO_SCRIPT:
28        hyphen_idx = lang.rfind('-')
29        assert hyphen_idx != -1, (
30            'We do not know what script the "%s" language is written in.'
31            % lang_code)
32        assumed_script = lang[hyphen_idx+1:]
33        if len(assumed_script) == 4 and assumed_script.isalpha():
34            # This is actually the script
35            return assumed_script.title()
36        lang = lang[:hyphen_idx]
37    return LANG_TO_SCRIPT[lang]
38
39
40def get_best_cmap(font):
41    font_file, index = font
42    font_path = path.join(_fonts_dir, font_file)
43    if index is not None:
44        ttfont = ttLib.TTFont(font_path, fontNumber=index)
45    else:
46        ttfont = ttLib.TTFont(font_path)
47    all_unicode_cmap = None
48    bmp_cmap = None
49    for cmap in ttfont['cmap'].tables:
50        specifier = (cmap.format, cmap.platformID, cmap.platEncID)
51        if specifier == (4, 3, 1):
52            assert bmp_cmap is None, 'More than one BMP cmap in %s' % (font, )
53            bmp_cmap = cmap
54        elif specifier == (12, 3, 10):
55            assert all_unicode_cmap is None, (
56                'More than one UCS-4 cmap in %s' % (font, ))
57            all_unicode_cmap = cmap
58
59    return all_unicode_cmap.cmap if all_unicode_cmap else bmp_cmap.cmap
60
61
62def assert_font_supports_any_of_chars(font, chars):
63    best_cmap = get_best_cmap(font)
64    for char in chars:
65        if char in best_cmap:
66            return
67    sys.exit('None of characters in %s were found in %s' % (chars, font))
68
69
70def check_hyphens(hyphens_dir):
71    # Find all the scripts that need automatic hyphenation
72    scripts = set()
73    for hyb_file in glob.iglob(path.join(hyphens_dir, '*.hyb')):
74        hyb_file = path.basename(hyb_file)
75        assert hyb_file.startswith('hyph-'), (
76            'Unknown hyphenation file %s' % hyb_file)
77        lang_code = hyb_file[hyb_file.index('-')+1:hyb_file.index('.')]
78        scripts.add(lang_to_script(lang_code))
79
80    HYPHENS = {0x002D, 0x2010}
81    for script in scripts:
82        fonts = _script_to_font_map[script]
83        assert fonts, 'No fonts found for the "%s" script' % script
84        for font in fonts:
85            assert_font_supports_any_of_chars(font, HYPHENS)
86
87
88def parse_fonts_xml(fonts_xml_path):
89    global _script_to_font_map, _fallback_chain
90    _script_to_font_map = collections.defaultdict(set)
91    _fallback_chain = []
92    tree = ElementTree.parse(fonts_xml_path)
93    for family in tree.findall('family'):
94        name = family.get('name')
95        variant = family.get('variant')
96        langs = family.get('lang')
97        if name:
98            assert variant is None, (
99                'No variant expected for LGC font %s.' % name)
100            assert langs is None, (
101                'No language expected for LGC fonts %s.' % name)
102        else:
103            assert variant in {None, 'elegant', 'compact'}, (
104                'Unexpected value for variant: %s' % variant)
105
106        if langs:
107            langs = langs.split()
108            scripts = {lang_to_script(lang) for lang in langs}
109        else:
110            scripts = set()
111
112        for child in family:
113            assert child.tag == 'font', (
114                'Unknown tag <%s>' % child.tag)
115            font_file = child.text
116            weight = int(child.get('weight'))
117            assert weight % 100 == 0, (
118                'Font weight "%d" is not a multiple of 100.' % weight)
119
120            style = child.get('style')
121            assert style in {'normal', 'italic'}, (
122                'Unknown style "%s"' % style)
123
124            index = child.get('index')
125            if index:
126                index = int(index)
127
128            _fallback_chain.append((
129                name,
130                frozenset(scripts),
131                variant,
132                weight,
133                style,
134                (font_file, index)))
135
136            if name: # non-empty names are used for default LGC fonts
137                map_scripts = {'Latn', 'Grek', 'Cyrl'}
138            else:
139                map_scripts = scripts
140            for script in map_scripts:
141                _script_to_font_map[script].add((font_file, index))
142
143
144def main():
145    target_out = sys.argv[1]
146    global _fonts_dir
147    _fonts_dir = path.join(target_out, 'fonts')
148
149    fonts_xml_path = path.join(target_out, 'etc', 'fonts.xml')
150    parse_fonts_xml(fonts_xml_path)
151
152    hyphens_dir = path.join(target_out, 'usr', 'hyphen-data')
153    check_hyphens(hyphens_dir)
154
155
156if __name__ == '__main__':
157    main()
158