mirror of
https://github.com/Kozea/WeasyPrint.git
synced 2024-10-05 00:21:15 +03:00
127 lines
4.6 KiB
Python
127 lines
4.6 KiB
Python
# coding: utf8
|
|
"""
|
|
weasyprint.text
|
|
---------------
|
|
|
|
Interface with Pango to decide where to do line breaks and to draw text.
|
|
|
|
:copyright: Copyright 2011-2012 Simon Sapin and contributors, see AUTHORS.
|
|
:license: BSD, see LICENSE for details.
|
|
|
|
"""
|
|
|
|
from __future__ import division, unicode_literals
|
|
|
|
import cairo
|
|
|
|
from cgi import escape
|
|
from gi.repository import Pango, PangoCairo # pylint: disable=E0611
|
|
|
|
|
|
PANGO_VARIANT = {
|
|
'normal': Pango.Variant.NORMAL,
|
|
'small-caps': Pango.Variant.SMALL_CAPS,
|
|
}
|
|
|
|
PANGO_STYLE = {
|
|
'normal': Pango.Style.NORMAL,
|
|
'italic': Pango.Style.ITALIC,
|
|
'oblique': Pango.Style.OBLIQUE,
|
|
}
|
|
|
|
NON_HINTED_DUMMY_CONTEXT = cairo.Context(cairo.PDFSurface(None, 1, 1))
|
|
HINTED_DUMMY_CONTEXT = cairo.Context(cairo.ImageSurface(
|
|
cairo.FORMAT_ARGB32, 1, 1))
|
|
|
|
|
|
def create_layout(text, style, hinting, max_width):
|
|
"""Return an opaque Pango object to be passed to other functions
|
|
in this module.
|
|
|
|
:param text: Unicode
|
|
:param style: a :class:`StyleDict` of computed values
|
|
:param hinting: whether to enable text hinting or not
|
|
:param max_width:
|
|
The maximum available width in the same unit as ``style.font_size``,
|
|
or ``None`` for unlimited width.
|
|
|
|
"""
|
|
layout = PangoCairo.create_layout(
|
|
HINTED_DUMMY_CONTEXT if hinting else NON_HINTED_DUMMY_CONTEXT)
|
|
font = Pango.FontDescription()
|
|
font.set_family(', '.join(style.font_family))
|
|
font.set_variant(PANGO_VARIANT[style.font_variant])
|
|
font.set_style(PANGO_STYLE[style.font_style])
|
|
font.set_absolute_size(Pango.units_from_double(style.font_size))
|
|
font.set_weight(style.font_weight)
|
|
layout.set_font_description(font)
|
|
layout.set_text(text, -1)
|
|
layout.set_wrap(Pango.WrapMode.WORD)
|
|
if max_width is not None:
|
|
layout.set_width(Pango.units_from_double(max_width))
|
|
word_spacing = style.word_spacing
|
|
letter_spacing = style.letter_spacing
|
|
if letter_spacing == 'normal':
|
|
letter_spacing = 0
|
|
if text and (word_spacing != 0 or letter_spacing != 0):
|
|
word_spacing = Pango.units_from_double(word_spacing)
|
|
letter_spacing = Pango.units_from_double(letter_spacing)
|
|
markup = escape(text).replace(
|
|
' ', '<span letter_spacing="%i"> </span>' % (
|
|
word_spacing + letter_spacing,))
|
|
markup = '<span letter_spacing="%i">%s</span>' % (
|
|
letter_spacing, markup)
|
|
attributes_list = Pango.parse_markup(markup, -1, '\x00')[1]
|
|
layout.set_attributes(attributes_list)
|
|
return layout
|
|
|
|
|
|
# TODO: use get_line instead of get_lines when it is not broken anymore
|
|
def split_first_line(*args, **kwargs):
|
|
"""Fit as much as possible in the available width for one line of text.
|
|
|
|
Return ``(length, width, height, resume_at)``.
|
|
|
|
``show_line``: a closure that takes a cairo Context and draws the
|
|
first line.
|
|
``length``: length in UTF-8 bytes of the first line
|
|
``width``: width in pixels of the first line
|
|
``height``: height in pixels of the first line
|
|
``baseline``: baseline in pixels of the first line
|
|
``resume_at``: The number of UTF-8 bytes to skip for the next line.
|
|
May be ``None`` if the whole text fits in one line.
|
|
This may be greater than ``length`` in case of preserved
|
|
newline characters.
|
|
|
|
"""
|
|
layout = create_layout(*args, **kwargs)
|
|
lines = layout.get_lines_readonly()
|
|
first_line = lines[0]
|
|
length = first_line.length
|
|
_ink_extents, logical_extents = first_line.get_extents()
|
|
width = Pango.units_to_double(logical_extents.width)
|
|
height = Pango.units_to_double(logical_extents.height)
|
|
baseline = Pango.units_to_double(layout.get_baseline())
|
|
resume_at = lines[1].start_index if len(lines) >= 2 else None
|
|
return layout, length, resume_at, width, height, baseline
|
|
|
|
|
|
def show_first_line(cairo_context, pango_layout, hinting):
|
|
"""Draw the given ``line`` to the Cairo ``context``."""
|
|
if hinting:
|
|
PangoCairo.update_layout(cairo_context, pango_layout)
|
|
lines = pango_layout.get_lines_readonly()
|
|
PangoCairo.show_layout_line(cairo_context, lines[0])
|
|
|
|
|
|
def line_widths(document, box, width, skip=None):
|
|
"""Return the width for each line."""
|
|
# TODO: without the lstrip, we get an extra empty line at the beginning. Is
|
|
# there a better solution to avoid that?
|
|
layout = create_layout(
|
|
box.text[(skip or 0):].lstrip(), box.style,
|
|
document.enable_hinting, width)
|
|
for line in layout.get_lines_readonly():
|
|
_ink_extents, logical_extents = line.get_extents()
|
|
yield Pango.units_to_double(logical_extents.width)
|