from fontTools.misc import sstruct
from fontTools.misc.textTools import bytesjoin, strjoin, readHex
from fontTools.ttLib import TTLibError
from . import DefaultTable
# Apple's documentation of 'meta':
# https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6meta.html
META_HEADER_FORMAT = """
> # big endian
version: L
flags: L
dataOffset: L
numDataMaps: L
"""
DATA_MAP_FORMAT = """
> # big endian
tag: 4s
dataOffset: L
dataLength: L
"""
[docs]
class table__m_e_t_a(DefaultTable.DefaultTable):
def __init__(self, tag=None):
DefaultTable.DefaultTable.__init__(self, tag)
self.data = {}
[docs]
def decompile(self, data, ttFont):
headerSize = sstruct.calcsize(META_HEADER_FORMAT)
header = sstruct.unpack(META_HEADER_FORMAT, data[0:headerSize])
if header["version"] != 1:
raise TTLibError("unsupported 'meta' version %d" % header["version"])
dataMapSize = sstruct.calcsize(DATA_MAP_FORMAT)
for i in range(header["numDataMaps"]):
dataMapOffset = headerSize + i * dataMapSize
dataMap = sstruct.unpack(
DATA_MAP_FORMAT, data[dataMapOffset : dataMapOffset + dataMapSize]
)
tag = dataMap["tag"]
offset = dataMap["dataOffset"]
self.data[tag] = data[offset : offset + dataMap["dataLength"]]
if tag in ["dlng", "slng"]:
self.data[tag] = self.data[tag].decode("utf-8")
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def compile(self, ttFont):
keys = sorted(self.data.keys())
headerSize = sstruct.calcsize(META_HEADER_FORMAT)
dataOffset = headerSize + len(keys) * sstruct.calcsize(DATA_MAP_FORMAT)
header = sstruct.pack(
META_HEADER_FORMAT,
{
"version": 1,
"flags": 0,
"dataOffset": dataOffset,
"numDataMaps": len(keys),
},
)
dataMaps = []
dataBlocks = []
for tag in keys:
if tag in ["dlng", "slng"]:
data = self.data[tag].encode("utf-8")
else:
data = self.data[tag]
dataMaps.append(
sstruct.pack(
DATA_MAP_FORMAT,
{"tag": tag, "dataOffset": dataOffset, "dataLength": len(data)},
)
)
dataBlocks.append(data)
dataOffset += len(data)
return bytesjoin([header] + dataMaps + dataBlocks)
[docs]
def toXML(self, writer, ttFont):
for tag in sorted(self.data.keys()):
if tag in ["dlng", "slng"]:
writer.begintag("text", tag=tag)
writer.newline()
writer.write(self.data[tag])
writer.newline()
writer.endtag("text")
writer.newline()
else:
writer.begintag("hexdata", tag=tag)
writer.newline()
data = self.data[tag]
if min(data) >= 0x20 and max(data) <= 0x7E:
writer.comment("ascii: " + data.decode("ascii"))
writer.newline()
writer.dumphex(data)
writer.endtag("hexdata")
writer.newline()
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def fromXML(self, name, attrs, content, ttFont):
if name == "hexdata":
self.data[attrs["tag"]] = readHex(content)
elif name == "text" and attrs["tag"] in ["dlng", "slng"]:
self.data[attrs["tag"]] = strjoin(content).strip()
else:
raise TTLibError("can't handle '%s' element" % name)