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Mini Shell
Mini Shell
#!/usr/bin/env python3
__license__ = 'GPL v3'
__copyright__ = '2012, Kovid Goyal <kovid at kovidgoyal.net>'
__docformat__ = 'restructuredtext en'
from io import BytesIO
from struct import calcsize, unpack, unpack_from
from collections import namedtuple
from calibre.utils.fonts.utils import get_font_names2, get_font_characteristics
class UnsupportedFont(ValueError):
pass
FontCharacteristics = namedtuple('FontCharacteristics',
'weight, is_italic, is_bold, is_regular, fs_type, panose, width, is_oblique, is_wws, os2_version')
FontNames = namedtuple('FontNames',
'family_name, subfamily_name, full_name, preferred_family_name, preferred_subfamily_name, wws_family_name, wws_subfamily_name')
class FontMetadata:
def __init__(self, bytes_or_stream):
if not hasattr(bytes_or_stream, 'read'):
bytes_or_stream = BytesIO(bytes_or_stream)
f = bytes_or_stream
f.seek(0)
header = f.read(4)
if header not in {b'\x00\x01\x00\x00', b'OTTO'}:
raise UnsupportedFont('Not a supported sfnt variant')
self.is_otf = header == b'OTTO'
self.read_table_metadata(f)
self.read_names(f)
self.read_characteristics(f)
f.seek(0)
self.font_family = self.names.family_name
wt = self.characteristics.weight
if wt == 400:
wt = 'normal'
elif wt == 700:
wt = 'bold'
else:
wt = str(wt)
self.font_weight = wt
self.font_stretch = ('ultra-condensed', 'extra-condensed',
'condensed', 'semi-condensed', 'normal', 'semi-expanded',
'expanded', 'extra-expanded', 'ultra-expanded')[
self.characteristics.width-1]
if self.characteristics.is_oblique:
self.font_style = 'oblique'
elif self.characteristics.is_italic:
self.font_style = 'italic'
else:
self.font_style = 'normal'
def read_table_metadata(self, f):
f.seek(4)
num_tables = unpack(b'>H', f.read(2))[0]
# Start of table record entries
f.seek(4 + 4*2)
table_record = b'>4s3L'
sz = calcsize(table_record)
self.tables = {}
block = f.read(sz * num_tables)
for i in range(num_tables):
table_tag, table_checksum, table_offset, table_length = \
unpack_from(table_record, block, i*sz)
self.tables[table_tag.lower()] = (table_offset, table_length,
table_checksum)
def read_names(self, f):
if b'name' not in self.tables:
raise UnsupportedFont('This font has no name table')
toff, tlen = self.tables[b'name'][:2]
f.seek(toff)
table = f.read(tlen)
if len(table) != tlen:
raise UnsupportedFont('This font has a name table of incorrect length')
vals = get_font_names2(table, raw_is_table=True)
self.names = FontNames(*vals)
def read_characteristics(self, f):
if b'os/2' not in self.tables:
raise UnsupportedFont('This font has no OS/2 table')
toff, tlen = self.tables[b'os/2'][:2]
f.seek(toff)
table = f.read(tlen)
if len(table) != tlen:
raise UnsupportedFont('This font has an OS/2 table of incorrect length')
vals = get_font_characteristics(table, raw_is_table=True)
self.characteristics = FontCharacteristics(*vals)
def to_dict(self):
ans = {
'is_otf':self.is_otf,
'font-family':self.font_family,
'font-weight':self.font_weight,
'font-style':self.font_style,
'font-stretch':self.font_stretch
}
for f in self.names._fields:
ans[f] = getattr(self.names, f)
for f in self.characteristics._fields:
ans[f] = getattr(self.characteristics, f)
return ans
if __name__ == '__main__':
import sys
with open(sys.argv[-1], 'rb') as f:
fm = FontMetadata(f)
import pprint
pprint.pprint(fm.to_dict())
Zerion Mini Shell 1.0