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‎examples/demo.py‎

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from examples import assets_dir
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from sfnttools.contract import SfntVersion
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from sfnttools.font import SfntFont, SfntFontCollection
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def main():
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example_file_path = assets_dir.joinpath('demo', 'demo.otf.woff2')
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example_font = SfntFont.load(example_file_path)
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if __name__ == '__main__':
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main()

‎src/sfnttools/contract.py‎

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from abc import abstractmethod
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from collections.abc import Iterator
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from enum import StrEnum
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from typing import Protocol, runtime_checkable
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from sfnttools.error import SfntError
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class SfntVersion(StrEnum):
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TRUE_TYPE = '\x00\x01\x00\x00'
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OPEN_TYPE = 'OTTO'
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MACOS_TRUE_TYPE = 'true'
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MACOS_TYPE_1 = 'typ1'
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class SfntFileTag(StrEnum):
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TTCF = 'ttcf'
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WOFF = 'wOFF'
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WOFF2 = 'wOF2'
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@runtime_checkable
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class SfntTable(Protocol):
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@staticmethod
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@abstractmethod
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def parse(data: bytes, reader: 'SfntReader') -> 'SfntTable':
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raise NotImplementedError()
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@abstractmethod
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def copy(self) -> 'SfntTable':
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raise NotImplementedError()
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@abstractmethod
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def dump(self) -> bytes:
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raise NotImplementedError()
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@runtime_checkable
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class SfntReader(Protocol):
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@abstractmethod
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def get_sfnt_version(self) -> SfntVersion:
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raise NotImplementedError()
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@abstractmethod
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def get_table_tags(self) -> Iterator[str]:
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raise NotImplementedError()
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@abstractmethod
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def get_table_from_cache(self, tag: str) -> SfntTable | None:
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raise NotImplementedError()
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@abstractmethod
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def set_table_to_cache(self, tag: str, table: SfntTable):
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raise NotImplementedError()
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@abstractmethod
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def read_table_data(self, tag: str) -> bytes:
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raise NotImplementedError()
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def parse_table(self, tag: str) -> SfntTable:
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table = self.get_table_from_cache(tag)
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if table is None:
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from sfnttools.tables import TABLE_TYPE_REGISTRY, DEFAULT_TABLE_TYPE
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table_type = TABLE_TYPE_REGISTRY.get(tag, DEFAULT_TABLE_TYPE)
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data = self.read_table_data(tag)
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table = table_type.parse(data, self)
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self.set_table_to_cache(tag, table)
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return table
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def parse_font(self) -> tuple[SfntVersion, dict[SfntVersion, SfntTable]]:
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sfnt_version = self.get_sfnt_version()
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tables = {}
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for tag in self.get_table_tags():
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if tag in tables:
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raise SfntError(f'table {repr(tag)} more than one')
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table = self.parse_table(tag)
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tables[tag] = table
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return sfnt_version, tables
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@runtime_checkable
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class SfntWriter(Protocol):
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pass

‎src/sfnttools/font.py‎

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from collections import UserDict, UserList
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from io import BytesIO
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from os import PathLike
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from typing import BinaryIO, Any
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from sfnttools.contract import SfntVersion, SfntFileTag, SfntTable
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from sfnttools.error import SfntError
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from sfnttools.internal.stream import Stream
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from sfnttools.tables import TABLE_TYPE_REGISTRY
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from sfnttools.woff.headers import WoffHeader
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from sfnttools.woff.reader import WoffReader
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from sfnttools.woff2.headers import Woff2Header
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from sfnttools.woff2.reader import Woff2Reader
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from sfnttools.xtf.headers import TableDirectory, TtcHeader
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from sfnttools.xtf.reader import XtfReader
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class WoffPayload:
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major_version: int
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minor_version: int
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metadata: bytes | None
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private_data: bytes | None
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def __init__(
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self,
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major_version: int = 0,
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minor_version: int = 0,
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metadata: bytes | None = None,
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private_data: bytes | None = None,
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):
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self.major_version = major_version
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self.minor_version = minor_version
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self.metadata = metadata
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self.private_data = private_data
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class SfntFont(UserDict[str, SfntTable]):
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@staticmethod
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def parse(
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stream: bytes | BinaryIO,
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font_index: int | None = None,
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verify_checksum: bool = False,
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) -> 'SfntFont':
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if isinstance(stream, bytes):
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stream = BytesIO(stream)
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stream = Stream(stream)
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stream.seek(0)
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tag = stream.read_tag()
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stream.seek(0)
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if tag == SfntFileTag.TTCF:
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if font_index is None:
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raise SfntError(f'must specify a font index in font collection')
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header = TtcHeader.parse(stream)
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table_directory = header.read_table_directory(stream, font_index)
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reader = XtfReader(stream, table_directory, verify_checksum, False, None)
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sfnt_version, tables = reader.parse_font()
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return SfntFont(sfnt_version, tables)
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elif tag == SfntFileTag.WOFF:
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header = WoffHeader.parse(stream)
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reader = WoffReader(stream, header, verify_checksum)
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sfnt_version, tables = reader.parse_font()
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metadata = header.read_metadata(stream)
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private_data = header.read_private_data(stream)
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woff_payload = WoffPayload(
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header.major_version,
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header.minor_version,
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metadata,
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private_data,
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)
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return SfntFont(sfnt_version, tables, woff_payload)
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elif tag == SfntFileTag.WOFF2:
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stream.seek(4)
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flavor = stream.read_tag()
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stream.seek(0)
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if flavor == SfntFileTag.TTCF:
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if font_index is None:
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raise SfntError(f'must specify a font index in font collection')
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header = Woff2Header.parse(stream)
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font_entry = header.collection_header.font_entries[font_index]
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elif flavor in [*SfntVersion]:
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header = Woff2Header.parse(stream)
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font_entry = header.simulate_single_font_entry()
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else:
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raise SfntError('unsupported SFNT font')
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uncompressed_stream = Stream(BytesIO(header.read_uncompressed_data(stream)))
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reader = Woff2Reader(uncompressed_stream, header, font_entry, False, None)
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sfnt_version, tables = reader.parse_font()
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metadata = header.read_metadata(stream)
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private_data = header.read_private_data(stream)
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woff_payload = WoffPayload(
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header.major_version,
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header.minor_version,
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metadata,
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private_data,
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)
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return SfntFont(sfnt_version, tables, woff_payload)
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elif tag in [*SfntVersion]:
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table_directory = TableDirectory.parse(stream)
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reader = XtfReader(stream, table_directory, verify_checksum, False, None)
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sfnt_version, tables = reader.parse_font()
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return SfntFont(sfnt_version, tables)
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else:
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raise SfntError('unsupported SFNT font')
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@staticmethod
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def load(
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file_path: str | PathLike[str],
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font_index: int | None = None,
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verify_checksum: bool = False,
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) -> 'SfntFont':
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with open(file_path, 'rb') as file:
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return SfntFont.parse(file, font_index, verify_checksum)
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sfnt_version: SfntVersion
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woff_payload: WoffPayload | None
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def __init__(
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self,
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sfnt_version: SfntVersion,
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tables: dict[str, SfntTable] | None = None,
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woff_payload: WoffPayload | None = None,
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):
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super().__init__(tables)
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self.sfnt_version = sfnt_version
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self.woff_payload = woff_payload
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def __setitem__(self, tag: Any, table: Any):
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if not isinstance(tag, str):
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raise KeyError("tag must be a 'str'")
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if len(tag) != 4:
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raise KeyError('tag length must be 4')
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if any(not 0x20 <= ord(c) <= 0x7E for c in tag):
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raise KeyError('tag contains illegal characters')
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if tag.startswith(' '):
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raise KeyError('tag cannot start with a space')
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if ' ' in tag.strip():
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raise KeyError('tag cannot contain spaces in between')
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table_type = TABLE_TYPE_REGISTRY.get(tag, SfntTable)
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if not isinstance(table, table_type):
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raise ValueError(f'bad table type for tag {repr(tag)}')
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super().__setitem__(tag, table)
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def __repr__(self) -> str:
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return object.__repr__(self)
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class SfntFontCollection(UserList[SfntFont]):
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@staticmethod
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def parse(
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stream: bytes | BinaryIO,
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verify_checksum: bool = False,
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share_tables: bool = True,
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) -> 'SfntFontCollection':
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if isinstance(stream, bytes):
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stream = BytesIO(stream)
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stream = Stream(stream)
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stream.seek(0)
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tag = stream.read_tag()
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stream.seek(0)
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if tag == SfntFileTag.TTCF:
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header = TtcHeader.parse(stream)
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collection_tables_cache = {}
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fonts = []
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for font_index in range(header.num_fonts):
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table_directory = header.read_table_directory(stream, font_index)
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reader = XtfReader(stream, table_directory, verify_checksum, share_tables, collection_tables_cache)
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sfnt_version, tables = reader.parse_font()
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font = SfntFont(sfnt_version, tables)
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fonts.append(font)
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return SfntFontCollection(fonts)
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elif tag == SfntFileTag.WOFF2:
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header = Woff2Header.parse(stream)
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if header.collection_header is None:
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raise SfntError('not a woff2 collection font')
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uncompressed_stream = Stream(BytesIO(header.read_uncompressed_data(stream)))
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collection_tables_cache = {}
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fonts = []
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for font_entry in header.collection_header.font_entries:
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reader = Woff2Reader(uncompressed_stream, header, font_entry, share_tables, collection_tables_cache)
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sfnt_version, tables = reader.parse_font()
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font = SfntFont(sfnt_version, tables)
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fonts.append(font)
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metadata = header.read_metadata(stream)
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private_data = header.read_private_data(stream)
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woff_payload = WoffPayload(
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header.major_version,
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header.minor_version,
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metadata,
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private_data,
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)
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return SfntFontCollection(fonts, woff_payload)
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else:
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raise SfntError('unsupported SFNT collection font')
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@staticmethod
222+
def load(
223+
file_path: str | PathLike[str],
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verify_checksum: bool = False,
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share_tables: bool = True,
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) -> 'SfntFontCollection':
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with open(file_path, 'rb') as file:
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return SfntFontCollection.parse(file, verify_checksum, share_tables)
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woff_payload: WoffPayload | None
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def __init__(
233+
self,
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fonts: list[SfntFont] | None = None,
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woff_payload: WoffPayload | None = None,
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):
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super().__init__(fonts)
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self.woff_payload = woff_payload
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def __repr__(self) -> str:
241+
return object.__repr__(self)

‎src/sfnttools/tables/__init__.py‎

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from typing import Final
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from sfnttools.tables.default import DefaultTable
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from sfnttools.tables.dsig import DsigTable
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from sfnttools.tables.head import HeadTable
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TABLE_TYPE_REGISTRY: Final = {
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'DSIG': DsigTable,
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'head': HeadTable,
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}
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DEFAULT_TABLE_TYPE: Final = DefaultTable

‎src/sfnttools/tables/default.py‎

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from sfnttools.contract import SfntTable, SfntReader
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class DefaultTable(SfntTable):
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@staticmethod
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def parse(data: bytes, reader: SfntReader) -> 'DefaultTable':
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return DefaultTable(data)
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data: bytes
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def __init__(self, data: bytes = b''):
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self.data = data
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def copy(self) -> 'DefaultTable':
15+
return DefaultTable(self.data)
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def dump(self) -> bytes:
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return self.data

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