inkstitch/lib/lettering/font_variant.py

115 wiersze
4.1 KiB
Python

# Authors: see git history
#
# Copyright (c) 2010 Authors
# Licensed under the GNU GPL version 3.0 or later. See the file LICENSE for details.
import os
import inkex
from ..svg.tags import (INKSCAPE_GROUPMODE, INKSCAPE_LABEL, SVG_GROUP_TAG,
SVG_PATH_TAG, SVG_USE_TAG)
from .glyph import Glyph
class FontVariant(object):
"""Represents a single variant of a font.
Each font may have multiple variants for left-to-right, right-to-left,
etc. Each variant has a set of Glyphs, one per character.
A FontVariant instance can be accessed as a dict by using a unicode
character as a key.
Properties:
path -- the path to the directory containing this font
variant -- the font variant, specified using one of the constants below
glyphs -- a dict of Glyphs, with the glyphs' unicode characters as keys.
"""
# We use unicode characters rather than English strings for font file names
# in order to be more approachable for languages other than English.
LEFT_TO_RIGHT = ""
RIGHT_TO_LEFT = ""
TOP_TO_BOTTOM = ""
BOTTOM_TO_TOP = ""
VARIANT_TYPES = (LEFT_TO_RIGHT, RIGHT_TO_LEFT, TOP_TO_BOTTOM, BOTTOM_TO_TOP)
@classmethod
def reversed_variant(cls, variant):
if variant == cls.LEFT_TO_RIGHT:
return cls.RIGHT_TO_LEFT
elif variant == cls.RIGHT_TO_LEFT:
return cls.LEFT_TO_RIGHT
elif variant == cls.TOP_TO_BOTTOM:
return cls.BOTTOM_TO_TOP
elif variant == cls.BOTTOM_TO_TOP:
return cls.TOP_TO_BOTTOM
else:
return None
def __init__(self, font_path, variant, default_glyph=None):
# If the font variant file does not exist, this constructor will
# raise an exception. The caller should catch it and decide
# what to do.
self.path = font_path
self.variant = variant
self.default_glyph = default_glyph
self.glyphs = {}
self._load_glyphs()
def _load_glyphs(self):
svg_path = os.path.join(self.path, "%s.svg" % self.variant)
svg = inkex.load_svg(svg_path).getroot()
svg = self._apply_transforms(svg)
glyph_layers = svg.xpath(".//svg:g[starts-with(@inkscape:label, 'GlyphLayer-')]", namespaces=inkex.NSS)
for layer in glyph_layers:
self._clean_group(layer)
layer.attrib[INKSCAPE_LABEL] = layer.attrib[INKSCAPE_LABEL].replace("GlyphLayer-", "", 1)
glyph_name = layer.attrib[INKSCAPE_LABEL]
self.glyphs[glyph_name] = Glyph(layer)
def _clean_group(self, group):
# We'll repurpose the layer as a container group labelled with the
# glyph.
del group.attrib[INKSCAPE_GROUPMODE]
# The layer may be marked invisible, so we'll clear the 'display'
# style and presentation attribute.
group.style.pop('display', None)
group.attrib.pop('display', None)
def _apply_transforms(self, svg):
# apply transforms to paths and use tags
for element in svg.iterdescendants((SVG_PATH_TAG, SVG_USE_TAG)):
transform = element.composed_transform()
if element.tag == SVG_PATH_TAG:
path = element.path.transform(transform)
element.set_path(path)
element.attrib.pop("transform", None)
if element.tag == SVG_USE_TAG:
oldx = element.get('x', 0)
oldy = element.get('y', 0)
newx, newy = transform.apply_to_point((oldx, oldy))
element.set('x', newx)
element.set('y', newy)
element.attrib.pop("transform", None)
# remove transforms after they have been applied
for group in svg.iterdescendants(SVG_GROUP_TAG):
group.attrib.pop('transform', None)
return svg
def __getitem__(self, character):
if character in self.glyphs:
return self.glyphs[character]
else:
return self.glyphs.get(self.default_glyph, None)
def __contains__(self, character):
return character in self.glyphs