Version 3.0.3
"""
A module for finding, managing, and using fonts across platforms.
This module provides a single :class:`FontManager` instance that can
be shared across backends and platforms. The :func:`findfont`
function returns the best TrueType (TTF) font file in the local or
system font path that matches the specified :class:`FontProperties`
instance. The :class:`FontManager` also handles Adobe Font Metrics
(AFM) font files for use by the PostScript backend.
The design is based on the `W3C Cascading Style Sheet, Level 1 (CSS1)
font specification <http://www.w3.org/TR/1998/REC-CSS2-19980512/>`_.
Future versions may implement the Level 2 or 2.1 specifications.
Experimental support is included for using `fontconfig` on Unix
variant platforms (Linux, OS X, Solaris). To enable it, set the
constant ``USE_FONTCONFIG`` in this file to ``True``. Fontconfig has
the advantage that it is the standard way to look up fonts on X11
platforms, so if a font is installed, it is much more likely to be
found.
"""
# KNOWN ISSUES
#
# - documentation
# - font variant is untested
# - font stretch is incomplete
# - font size is incomplete
# - default font algorithm needs improvement and testing
# - setWeights function needs improvement
# - 'light' is an invalid weight value, remove it.
# - update_fonts not implemented
from functools import lru_cache
import json
import logging
import os
from pathlib import Path
import subprocess
import sys
try:
from threading import Timer
except ImportError:
from dummy_threading import Timer
import warnings
import matplotlib as mpl
from matplotlib import afm, cbook, ft2font, rcParams, get_cachedir
from matplotlib.fontconfig_pattern import (
parse_fontconfig_pattern, generate_fontconfig_pattern)
_log = logging.getLogger(__name__)
USE_FONTCONFIG = False
font_scalings = {
'xx-small' : 0.579,
'x-small' : 0.694,
'small' : 0.833,
'medium' : 1.0,
'large' : 1.200,
'x-large' : 1.440,
'xx-large' : 1.728,
'larger' : 1.2,
'smaller' : 0.833,
None : 1.0}
stretch_dict = {
'ultra-condensed' : 100,
'extra-condensed' : 200,
'condensed' : 300,
'semi-condensed' : 400,
'normal' : 500,
'semi-expanded' : 600,
'expanded' : 700,
'extra-expanded' : 800,
'ultra-expanded' : 900}
weight_dict = {
'ultralight' : 100,
'light' : 200,
'normal' : 400,
'regular' : 400,
'book' : 400,
'medium' : 500,
'roman' : 500,
'semibold' : 600,
'demibold' : 600,
'demi' : 600,
'bold' : 700,
'heavy' : 800,
'extra bold' : 800,
'black' : 900}
font_family_aliases = {
'serif',
'sans-serif',
'sans serif',
'cursive',
'fantasy',
'monospace',
'sans'}
# OS Font paths
MSFolders = \
r'Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders'
MSFontDirectories = [
r'SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts',
r'SOFTWARE\Microsoft\Windows\CurrentVersion\Fonts']
X11FontDirectories = [
# an old standard installation point
"/usr/X11R6/lib/X11/fonts/TTF/",
"/usr/X11/lib/X11/fonts",
# here is the new standard location for fonts
"/usr/share/fonts/",
# documented as a good place to install new fonts
"/usr/local/share/fonts/",
# common application, not really useful
"/usr/lib/openoffice/share/fonts/truetype/",
]
OSXFontDirectories = [
"/Library/Fonts/",
"/Network/Library/Fonts/",
"/System/Library/Fonts/",
# fonts installed via MacPorts
"/opt/local/share/fonts",
]
if not USE_FONTCONFIG and sys.platform != 'win32':
OSXFontDirectories.append(str(Path.home() / "Library/Fonts"))
X11FontDirectories.append(str(Path.home() / ".fonts"))
[docs]def get_fontext_synonyms(fontext):
"""
Return a list of file extensions extensions that are synonyms for
the given file extension *fileext*.
"""
return {'ttf': ('ttf', 'otf'),
'otf': ('ttf', 'otf'),
'afm': ('afm',)}[fontext]
[docs]def list_fonts(directory, extensions):
"""
Return a list of all fonts matching any of the extensions, found
recursively under the directory.
"""
extensions = ["." + ext for ext in extensions]
return [os.path.join(dirpath, filename)
# os.walk ignores access errors, unlike Path.glob.
for dirpath, _, filenames in os.walk(directory)
for filename in filenames
if Path(filename).suffix.lower() in extensions]
[docs]def win32FontDirectory():
r"""
Return the user-specified font directory for Win32. This is
looked up from the registry key::
\\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders\Fonts
If the key is not found, $WINDIR/Fonts will be returned.
"""
import winreg
try:
with winreg.OpenKey(winreg.HKEY_CURRENT_USER, MSFolders) as user:
return winreg.QueryValueEx(user, 'Fonts')[0]
except OSError:
return os.path.join(os.environ['WINDIR'], 'Fonts')
[docs]def win32InstalledFonts(directory=None, fontext='ttf'):
"""
Search for fonts in the specified font directory, or use the
system directories if none given. A list of TrueType font
filenames are returned by default, or AFM fonts if *fontext* ==
'afm'.
"""
import winreg
if directory is None:
directory = win32FontDirectory()
fontext = ['.' + ext for ext in get_fontext_synonyms(fontext)]
items = set()
for fontdir in MSFontDirectories:
try:
with winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, fontdir) as local:
for j in range(winreg.QueryInfoKey(local)[1]):
key, direc, tp = winreg.EnumValue(local, j)
if not isinstance(direc, str):
continue
# Work around for https://bugs.python.org/issue25778, which
# is fixed in Py>=3.6.1.
direc = direc.split("\0", 1)[0]
try:
path = Path(directory, direc).resolve()
except (FileNotFoundError, RuntimeError):
# Don't fail with invalid entries (FileNotFoundError is
# only necessary on Py3.5).
continue
if path.suffix.lower() in fontext:
items.add(str(path))
except (OSError, MemoryError):
continue
return list(items)
[docs]def OSXInstalledFonts(directories=None, fontext='ttf'):
"""Get list of font files on OS X."""
if directories is None:
directories = OSXFontDirectories
return [path
for directory in directories
for path in list_fonts(directory, get_fontext_synonyms(fontext))]
@lru_cache()
def _call_fc_list():
"""Cache and list the font filenames known to `fc-list`.
"""
# Delay the warning by 5s.
timer = Timer(5, lambda: warnings.warn(
'Matplotlib is building the font cache using fc-list. '
'This may take a moment.'))
timer.start()
try:
out = subprocess.check_output(['fc-list', '--format=%{file}\\n'])
except (OSError, subprocess.CalledProcessError):
return []
finally:
timer.cancel()
return [os.fsdecode(fname) for fname in out.split(b'\n')]
[docs]def get_fontconfig_fonts(fontext='ttf'):
"""List the font filenames known to `fc-list` having the given extension.
"""
fontext = ['.' + ext for ext in get_fontext_synonyms(fontext)]
return [fname for fname in _call_fc_list()
if Path(fname).suffix.lower() in fontext]
[docs]def findSystemFonts(fontpaths=None, fontext='ttf'):
"""
Search for fonts in the specified font paths. If no paths are
given, will use a standard set of system paths, as well as the
list of fonts tracked by fontconfig if fontconfig is installed and
available. A list of TrueType fonts are returned by default with
AFM fonts as an option.
"""
fontfiles = set()
fontexts = get_fontext_synonyms(fontext)
if fontpaths is None:
if sys.platform == 'win32':
fontpaths = [win32FontDirectory()]
# now get all installed fonts directly...
fontfiles.update(win32InstalledFonts(fontext=fontext))
else:
fontpaths = X11FontDirectories
fontfiles.update(get_fontconfig_fonts(fontext))
# check for OS X & load its fonts if present
if sys.platform == 'darwin':
fontfiles.update(OSXInstalledFonts(fontext=fontext))
elif isinstance(fontpaths, str):
fontpaths = [fontpaths]
for path in fontpaths:
fontfiles.update(map(os.path.abspath, list_fonts(path, fontexts)))
return [fname for fname in fontfiles if os.path.exists(fname)]
[docs]class FontEntry(object):
"""
A class for storing Font properties. It is used when populating
the font lookup dictionary.
"""
def __init__(self,
fname ='',
name ='',
style ='normal',
variant='normal',
weight ='normal',
stretch='normal',
size ='medium',
):
self.fname = fname
self.name = name
self.style = style
self.variant = variant
self.weight = weight
self.stretch = stretch
try:
self.size = str(float(size))
except ValueError:
self.size = size
def __repr__(self):
return "<Font '%s' (%s) %s %s %s %s>" % (
self.name, os.path.basename(self.fname), self.style, self.variant,
self.weight, self.stretch)
[docs]def ttfFontProperty(font):
"""
Extract information from a TrueType font file.
Parameters
----------
font : `.FT2Font`
The TrueType font file from which information will be extracted.
Returns
-------
`FontEntry`
The extracted font properties.
"""
name = font.family_name
# Styles are: italic, oblique, and normal (default)
sfnt = font.get_sfnt()
# These tables are actually mac_roman-encoded, but mac_roman support may be
# missing in some alternative Python implementations and we are only going
# to look for ASCII substrings, where any ASCII-compatible encoding works.
sfnt2 = sfnt.get((1, 0, 0, 2), b'').decode('latin-1').lower()
sfnt4 = sfnt.get((1, 0, 0, 4), b'').decode('latin-1').lower()
if sfnt4.find('oblique') >= 0:
style = 'oblique'
elif sfnt4.find('italic') >= 0:
style = 'italic'
elif sfnt2.find('regular') >= 0:
style = 'normal'
elif font.style_flags & ft2font.ITALIC:
style = 'italic'
else:
style = 'normal'
# Variants are: small-caps and normal (default)
# !!!! Untested
if name.lower() in ['capitals', 'small-caps']:
variant = 'small-caps'
else:
variant = 'normal'
weight = next((w for w in weight_dict if sfnt4.find(w) >= 0), None)
if not weight:
if font.style_flags & ft2font.BOLD:
weight = 700
else:
weight = 400
# Stretch can be absolute and relative
# Absolute stretches are: ultra-condensed, extra-condensed, condensed,
# semi-condensed, normal, semi-expanded, expanded, extra-expanded,
# and ultra-expanded.
# Relative stretches are: wider, narrower
# Child value is: inherit
if (sfnt4.find('narrow') >= 0 or sfnt4.find('condensed') >= 0 or
sfnt4.find('cond') >= 0):
stretch = 'condensed'
elif sfnt4.find('demi cond') >= 0:
stretch = 'semi-condensed'
elif sfnt4.find('wide') >= 0 or sfnt4.find('expanded') >= 0:
stretch = 'expanded'
else:
stretch = 'normal'
# Sizes can be absolute and relative.
# Absolute sizes are: xx-small, x-small, small, medium, large, x-large,
# and xx-large.
# Relative sizes are: larger, smaller
# Length value is an absolute font size, e.g., 12pt
# Percentage values are in 'em's. Most robust specification.
if not font.scalable:
raise NotImplementedError("Non-scalable fonts are not supported")
size = 'scalable'
return FontEntry(font.fname, name, style, variant, weight, stretch, size)
[docs]def afmFontProperty(fontpath, font):
"""
Extract information from an AFM font file.
Parameters
----------
font : `.AFM`
The AFM font file from which information will be extracted.
Returns
-------
`FontEntry`
The extracted font properties.
"""
name = font.get_familyname()
fontname = font.get_fontname().lower()
# Styles are: italic, oblique, and normal (default)
if font.get_angle() != 0 or 'italic' in name.lower():
style = 'italic'
elif 'oblique' in name.lower():
style = 'oblique'
else:
style = 'normal'
# Variants are: small-caps and normal (default)
# !!!! Untested
if name.lower() in ['capitals', 'small-caps']:
variant = 'small-caps'
else:
variant = 'normal'
weight = font.get_weight().lower()
# Stretch can be absolute and relative
# Absolute stretches are: ultra-condensed, extra-condensed, condensed,
# semi-condensed, normal, semi-expanded, expanded, extra-expanded,
# and ultra-expanded.
# Relative stretches are: wider, narrower
# Child value is: inherit
if 'demi cond' in fontname:
stretch = 'semi-condensed'
elif 'narrow' in fontname or 'cond' in fontname:
stretch = 'condensed'
elif 'wide' in fontname or 'expanded' in fontname:
stretch = 'expanded'
else:
stretch = 'normal'
# Sizes can be absolute and relative.
# Absolute sizes are: xx-small, x-small, small, medium, large, x-large,
# and xx-large.
# Relative sizes are: larger, smaller
# Length value is an absolute font size, e.g., 12pt
# Percentage values are in 'em's. Most robust specification.
# All AFM fonts are apparently scalable.
size = 'scalable'
return FontEntry(fontpath, name, style, variant, weight, stretch, size)
[docs]def createFontList(fontfiles, fontext='ttf'):
"""
A function to create a font lookup list. The default is to create
a list of TrueType fonts. An AFM font list can optionally be
created.
"""
fontlist = []
# Add fonts from list of known font files.
seen = set()
for fpath in fontfiles:
_log.debug('createFontDict: %s', fpath)
fname = os.path.split(fpath)[1]
if fname in seen:
continue
else:
seen.add(fname)
if fontext == 'afm':
try:
with open(fpath, 'rb') as fh:
font = afm.AFM(fh)
except EnvironmentError:
_log.info("Could not open font file %s", fpath)
continue
except RuntimeError:
_log.info("Could not parse font file %s", fpath)
continue
try:
prop = afmFontProperty(fpath, font)
except KeyError:
continue
else:
try:
font = ft2font.FT2Font(fpath)
except RuntimeError:
_log.info("Could not open font file %s", fpath)
continue
except UnicodeError:
_log.info("Cannot handle unicode filenames")
continue
except OSError:
_log.info("IO error - cannot open font file %s", fpath)
continue
try:
prop = ttfFontProperty(font)
except (KeyError, RuntimeError, ValueError, NotImplementedError):
continue
fontlist.append(prop)
return fontlist
[docs]class FontProperties(object):
"""
A class for storing and manipulating font properties.
The font properties are those described in the `W3C Cascading
Style Sheet, Level 1
<http://www.w3.org/TR/1998/REC-CSS2-19980512/>`_ font
specification. The six properties are:
- family: A list of font names in decreasing order of priority.
The items may include a generic font family name, either
'serif', 'sans-serif', 'cursive', 'fantasy', or 'monospace'.
In that case, the actual font to be used will be looked up
from the associated rcParam.
- style: Either 'normal', 'italic' or 'oblique'.
- variant: Either 'normal' or 'small-caps'.
- stretch: A numeric value in the range 0-1000 or one of
'ultra-condensed', 'extra-condensed', 'condensed',
'semi-condensed', 'normal', 'semi-expanded', 'expanded',
'extra-expanded' or 'ultra-expanded'
- weight: A numeric value in the range 0-1000 or one of
'ultralight', 'light', 'normal', 'regular', 'book', 'medium',
'roman', 'semibold', 'demibold', 'demi', 'bold', 'heavy',
'extra bold', 'black'
- size: Either an relative value of 'xx-small', 'x-small',
'small', 'medium', 'large', 'x-large', 'xx-large' or an
absolute font size, e.g., 12
The default font property for TrueType fonts (as specified in the
default rcParams) is::
sans-serif, normal, normal, normal, normal, scalable.
Alternatively, a font may be specified using an absolute path to a
.ttf file, by using the *fname* kwarg.
The preferred usage of font sizes is to use the relative values,
e.g., 'large', instead of absolute font sizes, e.g., 12. This
approach allows all text sizes to be made larger or smaller based
on the font manager's default font size.
This class will also accept a `fontconfig
<https://www.freedesktop.org/wiki/Software/fontconfig/>`_ pattern, if it is
the only argument provided. See the documentation on `fontconfig patterns
<https://www.freedesktop.org/software/fontconfig/fontconfig-user.html>`_.
This support does not require fontconfig to be installed. We are merely
borrowing its pattern syntax for use here.
Note that Matplotlib's internal font manager and fontconfig use a
different algorithm to lookup fonts, so the results of the same pattern
may be different in Matplotlib than in other applications that use
fontconfig.
"""
def __init__(self,
family = None,
style = None,
variant= None,
weight = None,
stretch= None,
size = None,
fname = None, # if set, it's a hardcoded filename to use
_init = None # used only by copy()
):
self._family = _normalize_font_family(rcParams['font.family'])
self._slant = rcParams['font.style']
self._variant = rcParams['font.variant']
self._weight = rcParams['font.weight']
self._stretch = rcParams['font.stretch']
self._size = rcParams['font.size']
self._file = None
# This is used only by copy()
if _init is not None:
self.__dict__.update(_init.__dict__)
return
if isinstance(family, str):
# Treat family as a fontconfig pattern if it is the only
# parameter provided.
if (style is None and
variant is None and
weight is None and
stretch is None and
size is None and
fname is None):
self.set_fontconfig_pattern(family)
return
self.set_family(family)
self.set_style(style)
self.set_variant(variant)
self.set_weight(weight)
self.set_stretch(stretch)
self.set_file(fname)
self.set_size(size)
def _parse_fontconfig_pattern(self, pattern):
return parse_fontconfig_pattern(pattern)
def __hash__(self):
l = (tuple(self.get_family()),
self.get_slant(),
self.get_variant(),
self.get_weight(),
self.get_stretch(),
self.get_size_in_points(),
self.get_file())
return hash(l)
def __eq__(self, other):
return hash(self) == hash(other)
def __str__(self):
return self.get_fontconfig_pattern()
[docs] def get_family(self):
"""
Return a list of font names that comprise the font family.
"""
return self._family
[docs] def get_name(self):
"""
Return the name of the font that best matches the font properties.
"""
return get_font(findfont(self)).family_name
[docs] def get_style(self):
"""
Return the font style. Values are: 'normal', 'italic' or 'oblique'.
"""
return self._slant
get_slant = get_style
[docs] def get_variant(self):
"""
Return the font variant. Values are: 'normal' or 'small-caps'.
"""
return self._variant
[docs] def get_weight(self):
"""
Set the font weight. Options are: A numeric value in the
range 0-1000 or one of 'light', 'normal', 'regular', 'book',
'medium', 'roman', 'semibold', 'demibold', 'demi', 'bold',
'heavy', 'extra bold', 'black'
"""
return self._weight
[docs] def get_stretch(self):
"""
Return the font stretch or width. Options are: 'ultra-condensed',
'extra-condensed', 'condensed', 'semi-condensed', 'normal',
'semi-expanded', 'expanded', 'extra-expanded', 'ultra-expanded'.
"""
return self._stretch
[docs] def get_fontconfig_pattern(self):
"""
Get a fontconfig pattern suitable for looking up the font as
specified with fontconfig's ``fc-match`` utility.
See the documentation on `fontconfig patterns
<https://www.freedesktop.org/software/fontconfig/fontconfig-user.html>`_.
This support does not require fontconfig to be installed or
support for it to be enabled. We are merely borrowing its
pattern syntax for use here.
"""
return generate_fontconfig_pattern(self)
[docs] def set_family(self, family):
"""
Change the font family. May be either an alias (generic name
is CSS parlance), such as: 'serif', 'sans-serif', 'cursive',
'fantasy', or 'monospace', a real font name or a list of real
font names. Real font names are not supported when
`text.usetex` is `True`.
"""
if family is None:
family = rcParams['font.family']
self._family = _normalize_font_family(family)
set_name = set_family
[docs] def set_style(self, style):
"""
Set the font style. Values are: 'normal', 'italic' or 'oblique'.
"""
if style is None:
style = rcParams['font.style']
if style not in ('normal', 'italic', 'oblique'):
raise ValueError("style must be normal, italic or oblique")
self._slant = style
set_slant = set_style
[docs] def set_variant(self, variant):
"""
Set the font variant. Values are: 'normal' or 'small-caps'.
"""
if variant is None:
variant = rcParams['font.variant']
if variant not in ('normal', 'small-caps'):
raise ValueError("variant must be normal or small-caps")
self._variant = variant
[docs] def set_weight(self, weight):
"""
Set the font weight. May be either a numeric value in the
range 0-1000 or one of 'ultralight', 'light', 'normal',
'regular', 'book', 'medium', 'roman', 'semibold', 'demibold',
'demi', 'bold', 'heavy', 'extra bold', 'black'
"""
if weight is None:
weight = rcParams['font.weight']
try:
weight = int(weight)
if weight < 0 or weight > 1000:
raise ValueError()
except ValueError:
if weight not in weight_dict:
raise ValueError("weight is invalid")
self._weight = weight
[docs] def set_stretch(self, stretch):
"""
Set the font stretch or width. Options are: 'ultra-condensed',
'extra-condensed', 'condensed', 'semi-condensed', 'normal',
'semi-expanded', 'expanded', 'extra-expanded' or
'ultra-expanded', or a numeric value in the range 0-1000.
"""
if stretch is None:
stretch = rcParams['font.stretch']
try:
stretch = int(stretch)
if stretch < 0 or stretch > 1000:
raise ValueError()
except ValueError:
if stretch not in stretch_dict:
raise ValueError("stretch is invalid")
self._stretch = stretch
[docs] def set_size(self, size):
"""
Set the font size. Either an relative value of 'xx-small',
'x-small', 'small', 'medium', 'large', 'x-large', 'xx-large'
or an absolute font size, e.g., 12.
"""
if size is None:
size = rcParams['font.size']
try:
size = float(size)
except ValueError:
try:
scale = font_scalings[size]
except KeyError:
raise ValueError(
"Size is invalid. Valid font size are "
+ ", ".join(map(str, font_scalings)))
else:
size = scale * FontManager.get_default_size()
if size < 1.0:
_log.info('Fontsize %1.2f < 1.0 pt not allowed by FreeType. '
'Setting fontsize = 1 pt', size)
size = 1.0
self._size = size
[docs] def set_file(self, file):
"""
Set the filename of the fontfile to use. In this case, all
other properties will be ignored.
"""
self._file = file
[docs] def set_fontconfig_pattern(self, pattern):
"""
Set the properties by parsing a fontconfig *pattern*.
See the documentation on `fontconfig patterns
<https://www.freedesktop.org/software/fontconfig/fontconfig-user.html>`_.
This support does not require fontconfig to be installed or
support for it to be enabled. We are merely borrowing its
pattern syntax for use here.
"""
for key, val in self._parse_fontconfig_pattern(pattern).items():
if type(val) == list:
getattr(self, "set_" + key)(val[0])
else:
getattr(self, "set_" + key)(val)
[docs]class JSONEncoder(json.JSONEncoder):
[docs] def default(self, o):
if isinstance(o, FontManager):
return dict(o.__dict__, __class__='FontManager')
elif isinstance(o, FontEntry):
d = dict(o.__dict__, __class__='FontEntry')
try:
# Cache paths of fonts shipped with mpl relative to the mpl
# data path, which helps in the presence of venvs.
d["fname"] = str(
Path(d["fname"]).relative_to(mpl.get_data_path()))
except ValueError:
pass
return d
else:
return super().default(o)
def _json_decode(o):
cls = o.pop('__class__', None)
if cls is None:
return o
elif cls == 'FontManager':
r = FontManager.__new__(FontManager)
r.__dict__.update(o)
return r
elif cls == 'FontEntry':
r = FontEntry.__new__(FontEntry)
r.__dict__.update(o)
if not os.path.isabs(r.fname):
r.fname = os.path.join(mpl.get_data_path(), r.fname)
return r
else:
raise ValueError("don't know how to deserialize __class__=%s" % cls)
[docs]def json_dump(data, filename):
"""
Dumps a data structure as JSON in the named file.
Handles FontManager and its fields. File paths that are children of the
Matplotlib data path (typically, fonts shipped with Matplotlib) are stored
relative to that data path (to remain valid across virtualenvs).
"""
with open(filename, 'w') as fh:
try:
json.dump(data, fh, cls=JSONEncoder, indent=2)
except OSError as e:
warnings.warn('Could not save font_manager cache {}'.format(e))
[docs]def json_load(filename):
"""
Loads a data structure as JSON from the named file.
Handles FontManager and its fields. Relative file paths are interpreted
as being relative to the Matplotlib data path, and transformed into
absolute paths.
"""
with open(filename, 'r') as fh:
return json.load(fh, object_hook=_json_decode)
def _normalize_font_family(family):
if isinstance(family, str):
family = [family]
return family
[docs]@cbook.deprecated("3.0")
class TempCache(object):
"""
A class to store temporary caches that are (a) not saved to disk
and (b) invalidated whenever certain font-related
rcParams---namely the family lookup lists---are changed or the
font cache is reloaded. This avoids the expensive linear search
through all fonts every time a font is looked up.
"""
# A list of rcparam names that, when changed, invalidated this
# cache.
invalidating_rcparams = (
'font.serif', 'font.sans-serif', 'font.cursive', 'font.fantasy',
'font.monospace')
def __init__(self):
self._lookup_cache = {}
self._last_rcParams = self.make_rcparams_key()
[docs] def make_rcparams_key(self):
return [id(fontManager)] + [
rcParams[param] for param in self.invalidating_rcparams]
[docs] def get(self, prop):
key = self.make_rcparams_key()
if key != self._last_rcParams:
self._lookup_cache = {}
self._last_rcParams = key
return self._lookup_cache.get(prop)
[docs] def set(self, prop, value):
key = self.make_rcparams_key()
if key != self._last_rcParams:
self._lookup_cache = {}
self._last_rcParams = key
self._lookup_cache[prop] = value
[docs]class FontManager(object):
"""
On import, the :class:`FontManager` singleton instance creates a
list of TrueType fonts based on the font properties: name, style,
variant, weight, stretch, and size. The :meth:`findfont` method
does a nearest neighbor search to find the font that most closely
matches the specification. If no good enough match is found, a
default font is returned.
"""
# Increment this version number whenever the font cache data
# format or behavior has changed and requires a existing font
# cache files to be rebuilt.
__version__ = 300
def __init__(self, size=None, weight='normal'):
self._version = self.__version__
self.__default_weight = weight
self.default_size = size
paths = [os.path.join(rcParams['datapath'], 'fonts', 'ttf'),
os.path.join(rcParams['datapath'], 'fonts', 'afm'),
os.path.join(rcParams['datapath'], 'fonts', 'pdfcorefonts')]
# Create list of font paths
for pathname in ['TTFPATH', 'AFMPATH']:
if pathname in os.environ:
ttfpath = os.environ[pathname]
if ttfpath.find(';') >= 0: #win32 style
paths.extend(ttfpath.split(';'))
elif ttfpath.find(':') >= 0: # unix style
paths.extend(ttfpath.split(':'))
else:
paths.append(ttfpath)
_log.debug('font search path %s', str(paths))
# Load TrueType fonts and create font dictionary.
self.defaultFamily = {
'ttf': 'DejaVu Sans',
'afm': 'Helvetica'}
self.defaultFont = {}
ttffiles = findSystemFonts(paths) + findSystemFonts()
self.defaultFont['ttf'] = next(
(fname for fname in ttffiles
if fname.lower().endswith("dejavusans.ttf")),
ttffiles[0])
self.ttflist = createFontList(ttffiles)
afmfiles = (findSystemFonts(paths, fontext='afm')
+ findSystemFonts(fontext='afm'))
self.afmlist = createFontList(afmfiles, fontext='afm')
self.defaultFont['afm'] = afmfiles[0] if afmfiles else None
@property
@cbook.deprecated("3.0")
def ttffiles(self):
return [font.fname for font in self.ttflist]
@property
@cbook.deprecated("3.0")
def afmfiles(self):
return [font.fname for font in self.afmlist]
[docs] def get_default_weight(self):
"""
Return the default font weight.
"""
return self.__default_weight
[docs] @staticmethod
def get_default_size():
"""
Return the default font size.
"""
return rcParams['font.size']
[docs] def set_default_weight(self, weight):
"""
Set the default font weight. The initial value is 'normal'.
"""
self.__default_weight = weight
[docs] def update_fonts(self, filenames):
"""
Update the font dictionary with new font files.
Currently not implemented.
"""
# !!!! Needs implementing
raise NotImplementedError
# Each of the scoring functions below should return a value between
# 0.0 (perfect match) and 1.0 (terrible match)
[docs] def score_family(self, families, family2):
"""
Returns a match score between the list of font families in
*families* and the font family name *family2*.
An exact match at the head of the list returns 0.0.
A match further down the list will return between 0 and 1.
No match will return 1.0.
"""
if not isinstance(families, (list, tuple)):
families = [families]
elif len(families) == 0:
return 1.0
family2 = family2.lower()
step = 1 / len(families)
for i, family1 in enumerate(families):
family1 = family1.lower()
if family1 in font_family_aliases:
if family1 in ('sans', 'sans serif'):
family1 = 'sans-serif'
options = rcParams['font.' + family1]
options = [x.lower() for x in options]
if family2 in options:
idx = options.index(family2)
return (i + (idx / len(options))) * step
elif family1 == family2:
# The score should be weighted by where in the
# list the font was found.
return i * step
return 1.0
[docs] def score_style(self, style1, style2):
"""
Returns a match score between *style1* and *style2*.
An exact match returns 0.0.
A match between 'italic' and 'oblique' returns 0.1.
No match returns 1.0.
"""
if style1 == style2:
return 0.0
elif style1 in ('italic', 'oblique') and \
style2 in ('italic', 'oblique'):
return 0.1
return 1.0
[docs] def score_variant(self, variant1, variant2):
"""
Returns a match score between *variant1* and *variant2*.
An exact match returns 0.0, otherwise 1.0.
"""
if variant1 == variant2:
return 0.0
else:
return 1.0
[docs] def score_stretch(self, stretch1, stretch2):
"""
Returns a match score between *stretch1* and *stretch2*.
The result is the absolute value of the difference between the
CSS numeric values of *stretch1* and *stretch2*, normalized
between 0.0 and 1.0.
"""
try:
stretchval1 = int(stretch1)
except ValueError:
stretchval1 = stretch_dict.get(stretch1, 500)
try:
stretchval2 = int(stretch2)
except ValueError:
stretchval2 = stretch_dict.get(stretch2, 500)
return abs(stretchval1 - stretchval2) / 1000.0
[docs] def score_weight(self, weight1, weight2):
"""
Returns a match score between *weight1* and *weight2*.
The result is 0.0 if both weight1 and weight 2 are given as strings
and have the same value.
Otherwise, the result is the absolute value of the difference between
the CSS numeric values of *weight1* and *weight2*, normalized between
0.05 and 1.0.
"""
# exact match of the weight names, e.g. weight1 == weight2 == "regular"
if (isinstance(weight1, str) and
isinstance(weight2, str) and
weight1 == weight2):
return 0.0
try:
weightval1 = int(weight1)
except ValueError:
weightval1 = weight_dict.get(weight1, 500)
try:
weightval2 = int(weight2)
except ValueError:
weightval2 = weight_dict.get(weight2, 500)
return 0.95*(abs(weightval1 - weightval2) / 1000.0) + 0.05
[docs] def score_size(self, size1, size2):
"""
Returns a match score between *size1* and *size2*.
If *size2* (the size specified in the font file) is 'scalable', this
function always returns 0.0, since any font size can be generated.
Otherwise, the result is the absolute distance between *size1* and
*size2*, normalized so that the usual range of font sizes (6pt -
72pt) will lie between 0.0 and 1.0.
"""
if size2 == 'scalable':
return 0.0
# Size value should have already been
try:
sizeval1 = float(size1)
except ValueError:
sizeval1 = self.default_size * font_scalings[size1]
try:
sizeval2 = float(size2)
except ValueError:
return 1.0
return abs(sizeval1 - sizeval2) / 72.0
[docs] def findfont(self, prop, fontext='ttf', directory=None,
fallback_to_default=True, rebuild_if_missing=True):
"""
Search the font list for the font that most closely matches
the :class:`FontProperties` *prop*.
:meth:`findfont` performs a nearest neighbor search. Each
font is given a similarity score to the target font
properties. The first font with the highest score is
returned. If no matches below a certain threshold are found,
the default font (usually DejaVu Sans) is returned.
`directory`, is specified, will only return fonts from the
given directory (or subdirectory of that directory).
The result is cached, so subsequent lookups don't have to
perform the O(n) nearest neighbor search.
If `fallback_to_default` is True, will fallback to the default
font family (usually "DejaVu Sans" or "Helvetica") if
the first lookup hard-fails.
See the `W3C Cascading Style Sheet, Level 1
<http://www.w3.org/TR/1998/REC-CSS2-19980512/>`_ documentation
for a description of the font finding algorithm.
"""
# Pass the relevant rcParams (and the font manager, as `self`) to
# _findfont_cached so to prevent using a stale cache entry after an
# rcParam was changed.
rc_params = tuple(tuple(rcParams[key]) for key in [
"font.serif", "font.sans-serif", "font.cursive", "font.fantasy",
"font.monospace"])
return self._findfont_cached(
prop, fontext, directory, fallback_to_default, rebuild_if_missing,
rc_params)
@lru_cache()
def _findfont_cached(self, prop, fontext, directory, fallback_to_default,
rebuild_if_missing, rc_params):
if not isinstance(prop, FontProperties):
prop = FontProperties(prop)
fname = prop.get_file()
if fname is not None:
_log.debug('findfont returning %s', fname)
return fname
if fontext == 'afm':
fontlist = self.afmlist
else:
fontlist = self.ttflist
best_score = 1e64
best_font = None
for font in fontlist:
if (directory is not None and
Path(directory) not in Path(font.fname).parents):
continue
# Matching family should have highest priority, so it is multiplied
# by 10.0
score = \
self.score_family(prop.get_family(), font.name) * 10.0 + \
self.score_style(prop.get_style(), font.style) + \
self.score_variant(prop.get_variant(), font.variant) + \
self.score_weight(prop.get_weight(), font.weight) + \
self.score_stretch(prop.get_stretch(), font.stretch) + \
self.score_size(prop.get_size(), font.size)
if score < best_score:
best_score = score
best_font = font
if score == 0:
break
if best_font is None or best_score >= 10.0:
if fallback_to_default:
warnings.warn(
'findfont: Font family %s not found. Falling back to %s.' %
(prop.get_family(), self.defaultFamily[fontext]))
default_prop = prop.copy()
default_prop.set_family(self.defaultFamily[fontext])
return self.findfont(default_prop, fontext, directory, False)
else:
# This is a hard fail -- we can't find anything reasonable,
# so just return the DejuVuSans.ttf
warnings.warn('findfont: Could not match %s. Returning %s.' %
(prop, self.defaultFont[fontext]),
UserWarning)
result = self.defaultFont[fontext]
else:
_log.debug('findfont: Matching %s to %s (%r) with score of %f.',
prop, best_font.name, best_font.fname, best_score)
result = best_font.fname
if not os.path.isfile(result):
if rebuild_if_missing:
_log.info(
'findfont: Found a missing font file. Rebuilding cache.')
_rebuild()
return fontManager.findfont(
prop, fontext, directory, True, False)
else:
raise ValueError("No valid font could be found")
return result
[docs]@lru_cache()
def is_opentype_cff_font(filename):
"""
Returns True if the given font is a Postscript Compact Font Format
Font embedded in an OpenType wrapper. Used by the PostScript and
PDF backends that can not subset these fonts.
"""
if os.path.splitext(filename)[1].lower() == '.otf':
with open(filename, 'rb') as fd:
return fd.read(4) == b"OTTO"
else:
return False
fontManager = None
_fmcache = None
_get_font = lru_cache(64)(ft2font.FT2Font)
[docs]def get_font(filename, hinting_factor=None):
if hinting_factor is None:
hinting_factor = rcParams['text.hinting_factor']
return _get_font(filename, hinting_factor)
# The experimental fontconfig-based backend.
if USE_FONTCONFIG and sys.platform != 'win32':
def fc_match(pattern, fontext):
fontexts = get_fontext_synonyms(fontext)
ext = "." + fontext
try:
pipe = subprocess.Popen(
['fc-match', '-s', '--format=%{file}\\n', pattern],
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
output = pipe.communicate()[0]
except OSError:
return None
# The bulk of the output from fc-list is ascii, so we keep the
# result in bytes and parse it as bytes, until we extract the
# filename, which is in sys.filesystemencoding().
if pipe.returncode == 0:
for fname in map(os.fsdecode, output.split(b'\n')):
if os.path.splitext(fname)[1][1:] in fontexts:
return fname
return None
_fc_match_cache = {}
def findfont(prop, fontext='ttf'):
if not isinstance(prop, str):
prop = prop.get_fontconfig_pattern()
cached = _fc_match_cache.get(prop)
if cached is not None:
return cached
result = fc_match(prop, fontext)
if result is None:
result = fc_match(':', fontext)
_fc_match_cache[prop] = result
return result
else:
_fmcache = None
cachedir = get_cachedir()
if cachedir is not None:
_fmcache = os.path.join(
cachedir, 'fontlist-v{}.json'.format(FontManager.__version__))
fontManager = None
def _rebuild():
global fontManager
fontManager = FontManager()
if _fmcache:
with cbook._lock_path(_fmcache):
json_dump(fontManager, _fmcache)
_log.debug("generated new fontManager")
if _fmcache:
try:
fontManager = json_load(_fmcache)
if (not hasattr(fontManager, '_version') or
fontManager._version != FontManager.__version__):
_rebuild()
else:
fontManager.default_size = None
_log.debug("Using fontManager instance from %s", _fmcache)
except TimeoutError:
raise
except Exception:
_rebuild()
else:
_rebuild()
[docs] def findfont(prop, **kw):
global fontManager
font = fontManager.findfont(prop, **kw)
return font