mirror of
https://github.com/Kozea/WeasyPrint.git
synced 2024-10-05 16:37:47 +03:00
1160 lines
39 KiB
Python
1160 lines
39 KiB
Python
# coding: utf-8
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"""
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weasyprint.text
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---------------
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Interface with Pango to decide where to do line breaks and to draw text.
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:copyright: Copyright 2011-2014 Simon Sapin and contributors, see AUTHORS.
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:license: BSD, see LICENSE for details.
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"""
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from __future__ import division
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import re
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import warnings
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import cairocffi as cairo
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import cffi
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import pyphen
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from .compat import basestring
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from .logger import LOGGER
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# XXX No unicode_literals, cffi likes native strings
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if cairo.cairo_version() <= 11400:
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warnings.warn('There are known rendering problems with Cairo <= 1.14.0')
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PANGO_ATTR_FONT_FEATURES_CACHE = {}
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ffi = cffi.FFI()
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ffi.cdef('''
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// Cairo
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typedef enum {
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CAIRO_FONT_TYPE_TOY,
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CAIRO_FONT_TYPE_FT,
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CAIRO_FONT_TYPE_WIN32,
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CAIRO_FONT_TYPE_QUARTZ,
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CAIRO_FONT_TYPE_USER
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} cairo_font_type_t;
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// Pango
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typedef unsigned int guint;
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typedef int gint;
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typedef char gchar;
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typedef gint gboolean;
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typedef void* gpointer;
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typedef ... cairo_t;
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typedef ... PangoLayout;
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typedef ... PangoContext;
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typedef ... PangoFontMap;
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typedef ... PangoFontMetrics;
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typedef ... PangoLanguage;
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typedef ... PangoTabArray;
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typedef ... PangoFontDescription;
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typedef ... PangoLayoutIter;
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typedef ... PangoAttrList;
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typedef ... PangoAttrClass;
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typedef enum {
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PANGO_STYLE_NORMAL,
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PANGO_STYLE_OBLIQUE,
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PANGO_STYLE_ITALIC
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} PangoStyle;
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typedef enum {
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PANGO_WEIGHT_THIN = 100,
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PANGO_WEIGHT_ULTRALIGHT = 200,
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PANGO_WEIGHT_LIGHT = 300,
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PANGO_WEIGHT_BOOK = 380,
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PANGO_WEIGHT_NORMAL = 400,
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PANGO_WEIGHT_MEDIUM = 500,
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PANGO_WEIGHT_SEMIBOLD = 600,
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PANGO_WEIGHT_BOLD = 700,
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PANGO_WEIGHT_ULTRABOLD = 800,
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PANGO_WEIGHT_HEAVY = 900,
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PANGO_WEIGHT_ULTRAHEAVY = 1000
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} PangoWeight;
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typedef enum {
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PANGO_STRETCH_ULTRA_CONDENSED,
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PANGO_STRETCH_EXTRA_CONDENSED,
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PANGO_STRETCH_CONDENSED,
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PANGO_STRETCH_SEMI_CONDENSED,
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PANGO_STRETCH_NORMAL,
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PANGO_STRETCH_SEMI_EXPANDED,
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PANGO_STRETCH_EXPANDED,
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PANGO_STRETCH_EXTRA_EXPANDED,
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PANGO_STRETCH_ULTRA_EXPANDED
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} PangoStretch;
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typedef enum {
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PANGO_WRAP_WORD,
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PANGO_WRAP_CHAR,
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PANGO_WRAP_WORD_CHAR
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} PangoWrapMode;
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typedef enum {
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PANGO_TAB_LEFT
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} PangoTabAlign;
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typedef struct {
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const PangoAttrClass *klass;
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guint start_index;
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guint end_index;
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} PangoAttribute;
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typedef struct {
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PangoLayout *layout;
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gint start_index;
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gint length;
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/* ... */
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} PangoLayoutLine;
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typedef struct {
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int x;
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int y;
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int width;
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int height;
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} PangoRectangle;
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int pango_version (void);
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double pango_units_to_double (int i);
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int pango_units_from_double (double d);
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void g_object_unref (gpointer object);
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void g_type_init (void);
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void pango_layout_set_width (PangoLayout *layout, int width);
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void pango_layout_set_attributes (
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PangoLayout *layout, PangoAttrList *attrs);
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void pango_layout_set_text (
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PangoLayout *layout, const char *text, int length);
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void pango_layout_set_tabs (
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PangoLayout *layout, PangoTabArray *tabs);
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void pango_layout_set_font_description (
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PangoLayout *layout, const PangoFontDescription *desc);
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void pango_layout_set_wrap (
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PangoLayout *layout, PangoWrapMode wrap);
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PangoLayoutIter * pango_layout_get_iter (PangoLayout *layout);
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void pango_layout_iter_free (PangoLayoutIter *iter);
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gboolean pango_layout_iter_next_line (PangoLayoutIter *iter);
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PangoLayoutLine * pango_layout_iter_get_line_readonly (
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PangoLayoutIter *iter);
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int pango_layout_iter_get_baseline (PangoLayoutIter *iter);
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PangoFontDescription * pango_font_description_new (void);
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void pango_font_description_free (PangoFontDescription *desc);
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void pango_font_description_set_family (
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PangoFontDescription *desc, const char *family);
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void pango_font_description_set_style (
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PangoFontDescription *desc, PangoStyle style);
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void pango_font_description_set_stretch (
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PangoFontDescription *desc, PangoStretch stretch);
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void pango_font_description_set_weight (
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PangoFontDescription *desc, PangoWeight weight);
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void pango_font_description_set_absolute_size (
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PangoFontDescription *desc, double size);
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PangoFontMetrics * pango_context_get_metrics (
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PangoContext *context, const PangoFontDescription *desc,
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PangoLanguage *language);
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void pango_font_metrics_unref (PangoFontMetrics *metrics);
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int pango_font_metrics_get_ascent (PangoFontMetrics *metrics);
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int pango_font_metrics_get_descent (PangoFontMetrics *metrics);
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int pango_font_metrics_get_approximate_char_width (
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PangoFontMetrics *metrics);
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int pango_font_metrics_get_approximate_digit_width (
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PangoFontMetrics *metrics);
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int pango_font_metrics_get_underline_thickness (
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PangoFontMetrics *metrics);
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int pango_font_metrics_get_underline_position (
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PangoFontMetrics *metrics);
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int pango_font_metrics_get_strikethrough_thickness (
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PangoFontMetrics *metrics);
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int pango_font_metrics_get_strikethrough_position (
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PangoFontMetrics *metrics);
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PangoAttrList * pango_attr_list_new (void);
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void pango_attr_list_unref (PangoAttrList *list);
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void pango_attr_list_insert (
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PangoAttrList *list, PangoAttribute *attr);
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PangoAttribute * pango_attr_font_features_new (const gchar *features);
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PangoAttribute * pango_attr_letter_spacing_new (int letter_spacing);
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void pango_attribute_destroy (PangoAttribute *attr);
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PangoTabArray * pango_tab_array_new_with_positions (
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gint size, gboolean positions_in_pixels, PangoTabAlign first_alignment,
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gint first_position, ...);
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void pango_tab_array_free (PangoTabArray *tab_array);
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PangoLanguage * pango_language_from_string (const char *language);
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PangoLanguage * pango_language_get_default (void);
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void pango_context_set_language (
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PangoContext *context, PangoLanguage *language);
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void pango_context_set_font_map (
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PangoContext *context, PangoFontMap *font_map);
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void pango_layout_line_get_extents (
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PangoLayoutLine *line,
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PangoRectangle *ink_rect, PangoRectangle *logical_rect);
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PangoContext * pango_layout_get_context (PangoLayout *layout);
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// PangoCairo
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PangoLayout * pango_cairo_create_layout (cairo_t *cr);
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void pango_cairo_update_layout (cairo_t *cr, PangoLayout *layout);
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void pango_cairo_show_layout_line (cairo_t *cr, PangoLayoutLine *line);
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''')
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def dlopen(ffi, *names):
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"""Try various names for the same library, for different platforms."""
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for name in names:
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try:
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return ffi.dlopen(name)
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except OSError:
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pass
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# Re-raise the exception.
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return ffi.dlopen(names[0]) # pragma: no cover
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gobject = dlopen(ffi, 'gobject-2.0', 'libgobject-2.0-0', 'libgobject-2.0.so',
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'libgobject-2.0.dylib')
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pango = dlopen(ffi, 'pango-1.0', 'libpango-1.0-0', 'libpango-1.0.so',
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'libpango-1.0.dylib')
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pangocairo = dlopen(ffi, 'pangocairo-1.0', 'libpangocairo-1.0-0',
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'libpangocairo-1.0.so', 'libpangocairo-1.0.dylib')
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gobject.g_type_init()
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units_to_double = pango.pango_units_to_double
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units_from_double = pango.pango_units_from_double
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PYPHEN_DICTIONARY_CACHE = {}
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PANGO_STYLE = {
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'normal': pango.PANGO_STYLE_NORMAL,
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'oblique': pango.PANGO_STYLE_OBLIQUE,
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'italic': pango.PANGO_STYLE_ITALIC,
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}
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PANGO_STRETCH = {
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'ultra-condensed': pango.PANGO_STRETCH_ULTRA_CONDENSED,
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'extra-condensed': pango.PANGO_STRETCH_EXTRA_CONDENSED,
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'condensed': pango.PANGO_STRETCH_CONDENSED,
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'semi-condensed': pango.PANGO_STRETCH_SEMI_CONDENSED,
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'normal': pango.PANGO_STRETCH_NORMAL,
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'semi-expanded': pango.PANGO_STRETCH_SEMI_EXPANDED,
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'expanded': pango.PANGO_STRETCH_EXPANDED,
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'extra-expanded': pango.PANGO_STRETCH_EXTRA_EXPANDED,
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'ultra-expanded': pango.PANGO_STRETCH_ULTRA_EXPANDED,
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}
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PANGO_WRAP_MODE = {
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'WRAP_WORD': pango.PANGO_WRAP_WORD,
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'WRAP_CHAR': pango.PANGO_WRAP_CHAR,
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'WRAP_WORD_CHAR': pango.PANGO_WRAP_WORD_CHAR
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}
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# From http://www.microsoft.com/typography/otspec/languagetags.htm
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LST_TO_ISO = {
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'aba': 'abq',
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'afk': 'afr',
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'afr': 'aar',
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'agw': 'ahg',
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'als': 'gsw',
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'alt': 'atv',
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'ari': 'aiw',
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'ark': 'mhv',
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'ath': 'apk',
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'avr': 'ava',
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'bad': 'bfq',
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'bad0': 'bad',
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'bag': 'bfy',
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'bal': 'krc',
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'bau': 'bci',
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'bch': 'bcq',
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'bgr': 'bul',
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'bil': 'byn',
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'bkf': 'bla',
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'bli': 'bal',
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'bln': 'bjt',
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'blt': 'bft',
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'bmb': 'bam',
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'bri': 'bra',
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'brm': 'mya',
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'bsh': 'bak',
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'bti': 'btb',
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'chg': 'sgw',
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'chh': 'hne',
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'chi': 'nya',
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'chk': 'ckt',
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'chk0': 'chk',
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'chu': 'chv',
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'chy': 'chy',
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'cmr': 'swb',
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'crr': 'crx',
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'crt': 'crh',
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'csl': 'chu',
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'csy': 'ces',
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'dcr': 'cwd',
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'dgr': 'doi',
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'djr': 'dje',
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'djr0': 'djr',
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'dng': 'ada',
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'dnk': 'din',
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'dri': 'prs',
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'dun': 'dng',
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'dzn': 'dzo',
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'ebi': 'igb',
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'ecr': 'crj',
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'edo': 'bin',
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'erz': 'myv',
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'esp': 'spa',
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'eti': 'est',
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'euq': 'eus',
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'evk': 'evn',
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'evn': 'eve',
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'fan': 'acf',
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'fan0': 'fan',
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'far': 'fas',
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'fji': 'fij',
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'fle': 'vls',
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'fne': 'enf',
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'fos': 'fao',
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'fri': 'fry',
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'frl': 'fur',
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'frp': 'frp',
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'fta': 'fuf',
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'gad': 'gaa',
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'gae': 'gla',
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'gal': 'glg',
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'gaw': 'gbm',
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'gil': 'niv',
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'gil0': 'gil',
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'gmz': 'guk',
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'grn': 'kal',
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'gro': 'grt',
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'gua': 'grn',
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'hai': 'hat',
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'hal': 'flm',
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'har': 'hoj',
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'hbn': 'amf',
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'hma': 'mrj',
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'hnd': 'hno',
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'ho': 'hoc',
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'hri': 'har',
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'hye0': 'hye',
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'ijo': 'ijc',
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'ing': 'inh',
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'inu': 'iku',
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'iri': 'gle',
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'irt': 'gle',
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'ism': 'smn',
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'iwr': 'heb',
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'jan': 'jpn',
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'jii': 'yid',
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'jud': 'lad',
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'jul': 'dyu',
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'kab': 'kbd',
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'kab0': 'kab',
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'kac': 'kfr',
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'kal': 'kln',
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'kar': 'krc',
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'keb': 'ktb',
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'kge': 'kat',
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'kha': 'kjh',
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'khk': 'kca',
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'khs': 'kca',
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'khv': 'kca',
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'kis': 'kqs',
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'kkn': 'kex',
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'klm': 'xal',
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'kmb': 'kam',
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'kmn': 'kfy',
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'kmo': 'kmw',
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'kms': 'kxc',
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'knr': 'kau',
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'kod': 'kfa',
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'koh': 'okm',
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'kon': 'ktu',
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'kon0': 'kon',
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'kop': 'koi',
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'koz': 'kpv',
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'kpl': 'kpe',
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'krk': 'kaa',
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'krm': 'kdr',
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'krn': 'kar',
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'krt': 'kqy',
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'ksh': 'kas',
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'ksh0': 'ksh',
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'ksi': 'kha',
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'ksm': 'sjd',
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'kui': 'kxu',
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'kul': 'kfx',
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'kuu': 'kru',
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'kuy': 'kdt',
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'kyk': 'kpy',
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'lad': 'lld',
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'lah': 'bfu',
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'lak': 'lbe',
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'lam': 'lmn',
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'laz': 'lzz',
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'lcr': 'crm',
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'ldk': 'lbj',
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'lma': 'mhr',
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'lmb': 'lif',
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'lmw': 'ngl',
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'lsb': 'dsb',
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'lsm': 'smj',
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'lth': 'lit',
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'luh': 'luy',
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'lvi': 'lav',
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'maj': 'mpe',
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'mak': 'vmw',
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'man': 'mns',
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'map': 'arn',
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'maw': 'mwr',
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'mbn': 'kmb',
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'mch': 'mnc',
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'mcr': 'crm',
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'mde': 'men',
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'men': 'mym',
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'miz': 'lus',
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'mkr': 'mak',
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'mle': 'mdy',
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'mln': 'mlq',
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'mlr': 'mal',
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'mly': 'msa',
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'mnd': 'mnk',
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'mng': 'mon',
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'mnk': 'man',
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'mnx': 'glv',
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'mok': 'mdf',
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'mon': 'mnw',
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'mth': 'mai',
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'mts': 'mlt',
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'mun': 'unr',
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'nan': 'gld',
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'nas': 'nsk',
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'ncr': 'csw',
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'ndg': 'ndo',
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'nhc': 'csw',
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'nis': 'dap',
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'nkl': 'nyn',
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'nko': 'nqo',
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'nor': 'nob',
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'nsm': 'sme',
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'nta': 'nod',
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'nto': 'epo',
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'nyn': 'nno',
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'ocr': 'ojs',
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'ojb': 'oji',
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'oro': 'orm',
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'paa': 'sam',
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'pal': 'pli',
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'pap': 'plp',
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'pap0': 'pap',
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'pas': 'pus',
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'pgr': 'ell',
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'pil': 'fil',
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'plg': 'pce',
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'plk': 'pol',
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'ptg': 'por',
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'qin': 'bgr',
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'rbu': 'bxr',
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'rcr': 'atj',
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'rms': 'roh',
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'rom': 'ron',
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'roy': 'rom',
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'rsy': 'rue',
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'rua': 'kin',
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'sad': 'sck',
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'say': 'chp',
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'sek': 'xan',
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'sel': 'sel',
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'sgo': 'sag',
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'sgs': 'sgs',
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'sib': 'sjo',
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'sig': 'xst',
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'sks': 'sms',
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'sky': 'slk',
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'sla': 'scs',
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'sml': 'som',
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'sna': 'seh',
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'sna0': 'sna',
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'snh': 'sin',
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'sog': 'gru',
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|
'srb': 'srp',
|
|
'ssl': 'xsl',
|
|
'ssm': 'sma',
|
|
'sur': 'suq',
|
|
'sve': 'swe',
|
|
'swa': 'aii',
|
|
'swk': 'swa',
|
|
'swz': 'ssw',
|
|
'sxt': 'ngo',
|
|
'taj': 'tgk',
|
|
'tcr': 'cwd',
|
|
'tgn': 'ton',
|
|
'tgr': 'tig',
|
|
'tgy': 'tir',
|
|
'tht': 'tah',
|
|
'tib': 'bod',
|
|
'tkm': 'tuk',
|
|
'tmn': 'tem',
|
|
'tna': 'tsn',
|
|
'tne': 'enh',
|
|
'tng': 'toi',
|
|
'tod': 'xal',
|
|
'tod0': 'tod',
|
|
'trk': 'tur',
|
|
'tsg': 'tso',
|
|
'tua': 'tru',
|
|
'tul': 'tcy',
|
|
'tuv': 'tyv',
|
|
'twi': 'aka',
|
|
'usb': 'hsb',
|
|
'uyg': 'uig',
|
|
'vit': 'vie',
|
|
'vro': 'vro',
|
|
'wa': 'wbm',
|
|
'wag': 'wbr',
|
|
'wcr': 'crk',
|
|
'wel': 'cym',
|
|
'wlf': 'wol',
|
|
'xbd': 'khb',
|
|
'xhs': 'xho',
|
|
'yak': 'sah',
|
|
'yba': 'yor',
|
|
'ycr': 'cre',
|
|
'yim': 'iii',
|
|
'zhh': 'zho',
|
|
'zhp': 'zho',
|
|
'zhs': 'zho',
|
|
'zht': 'zho',
|
|
'znd': 'zne',
|
|
}
|
|
|
|
|
|
def utf8_slice(string, slice_):
|
|
return string.encode('utf-8')[slice_].decode('utf-8')
|
|
|
|
|
|
def unicode_to_char_p(string):
|
|
"""Return ``(pointer, bytestring)``.
|
|
|
|
The byte string must live at least as long as the pointer is used.
|
|
|
|
"""
|
|
bytestring = string.encode('utf8').replace(b'\x00', b'')
|
|
return ffi.new('char[]', bytestring), bytestring
|
|
|
|
|
|
def get_size(line, style):
|
|
logical_extents = ffi.new('PangoRectangle *')
|
|
pango.pango_layout_line_get_extents(line, ffi.NULL, logical_extents)
|
|
width, height = (units_to_double(logical_extents.width),
|
|
units_to_double(logical_extents.height))
|
|
if style.letter_spacing != 'normal':
|
|
width += style.letter_spacing
|
|
return width, height
|
|
|
|
|
|
def get_ink_position(line):
|
|
ink_extents = ffi.new('PangoRectangle *')
|
|
pango.pango_layout_line_get_extents(line, ink_extents, ffi.NULL)
|
|
return (units_to_double(ink_extents.x), units_to_double(ink_extents.y))
|
|
|
|
|
|
def first_line_metrics(first_line, text, layout, resume_at, space_collapse,
|
|
style, hyphenated=False, hyphenation_character=None):
|
|
length = first_line.length
|
|
if hyphenated:
|
|
length -= len(hyphenation_character.encode('utf8'))
|
|
elif resume_at:
|
|
# Set an infinite width as we don't want to break lines when drawing,
|
|
# the lines have already been split and the size may differ.
|
|
pango.pango_layout_set_width(layout.layout, -1)
|
|
# Create layout with final text
|
|
first_line_text = utf8_slice(text, slice(length))
|
|
# Remove trailing spaces if spaces collapse
|
|
if space_collapse:
|
|
first_line_text = first_line_text.rstrip(u' ')
|
|
# Remove soft hyphens
|
|
layout.set_text(first_line_text.replace(u'\u00ad', u''))
|
|
first_line = next(layout.iter_lines(), None)
|
|
length = first_line.length if first_line is not None else 0
|
|
soft_hyphens = 0
|
|
if u'\u00ad' in first_line_text:
|
|
if first_line_text[0] == u'\u00ad':
|
|
length += 2 # len(u'\u00ad'.encode('utf8'))
|
|
for i in range(len(layout.text_bytes.decode('utf8'))):
|
|
while i + soft_hyphens + 1 < len(first_line_text):
|
|
if first_line_text[i + soft_hyphens + 1] == u'\u00ad':
|
|
soft_hyphens += 1
|
|
else:
|
|
break
|
|
length += soft_hyphens * 2 # len(u'\u00ad'.encode('utf8'))
|
|
width, height = get_size(first_line, style)
|
|
baseline = units_to_double(pango.pango_layout_iter_get_baseline(ffi.gc(
|
|
pango.pango_layout_get_iter(layout.layout),
|
|
pango.pango_layout_iter_free)))
|
|
return layout, length, resume_at, width, height, baseline
|
|
|
|
|
|
class Layout(object):
|
|
"""Object holding PangoLayout-related cdata pointers."""
|
|
def __init__(self, context, font_size, style):
|
|
self.context = context
|
|
hinting = context.enable_hinting if context else False
|
|
cairo_dummy_context = (
|
|
cairo.Context(cairo.ImageSurface(cairo.FORMAT_ARGB32, 1, 1))
|
|
if hinting else cairo.Context(cairo.PDFSurface(None, 1, 1)))
|
|
self.layout = ffi.gc(
|
|
pangocairo.pango_cairo_create_layout(ffi.cast(
|
|
'cairo_t *', cairo_dummy_context._pointer)),
|
|
gobject.g_object_unref)
|
|
pango_context = pango.pango_layout_get_context(self.layout)
|
|
if context and context.font_config.font_map:
|
|
pango.pango_context_set_font_map(
|
|
pango_context, context.font_config.font_map)
|
|
self.font = ffi.gc(
|
|
pango.pango_font_description_new(),
|
|
pango.pango_font_description_free)
|
|
if style.font_language_override != 'normal':
|
|
lang_p, lang = unicode_to_char_p(LST_TO_ISO.get(
|
|
style.font_language_override.lower(),
|
|
style.font_language_override))
|
|
elif style.lang:
|
|
lang_p, lang = unicode_to_char_p(style.lang)
|
|
else:
|
|
lang = None
|
|
self.language = pango.pango_language_get_default()
|
|
if lang:
|
|
self.language = pango.pango_language_from_string(lang_p)
|
|
pango.pango_context_set_language(pango_context, self.language)
|
|
|
|
assert not isinstance(style.font_family, basestring), (
|
|
'font_family should be a list')
|
|
family_p, family = unicode_to_char_p(','.join(style.font_family))
|
|
pango.pango_font_description_set_family(self.font, family_p)
|
|
pango.pango_font_description_set_style(
|
|
self.font, PANGO_STYLE[style.font_style])
|
|
pango.pango_font_description_set_stretch(
|
|
self.font, PANGO_STRETCH[style.font_stretch])
|
|
pango.pango_font_description_set_weight(self.font, style.font_weight)
|
|
pango.pango_font_description_set_absolute_size(
|
|
self.font, units_from_double(font_size))
|
|
pango.pango_layout_set_font_description(self.layout, self.font)
|
|
|
|
def iter_lines(self):
|
|
layout_iter = ffi.gc(
|
|
pango.pango_layout_get_iter(self.layout),
|
|
pango.pango_layout_iter_free)
|
|
while 1:
|
|
yield pango.pango_layout_iter_get_line_readonly(layout_iter)
|
|
if not pango.pango_layout_iter_next_line(layout_iter):
|
|
return
|
|
|
|
def set_text(self, text):
|
|
text, bytestring = unicode_to_char_p(text)
|
|
self.text = text
|
|
self.text_bytes = bytestring
|
|
pango.pango_layout_set_text(self.layout, text, -1)
|
|
|
|
def get_font_metrics(self):
|
|
context = pango.pango_layout_get_context(self.layout)
|
|
return FontMetrics(context, self.font, self.language)
|
|
|
|
def set_wrap(self, wrap_mode):
|
|
pango.pango_layout_set_wrap(self.layout, wrap_mode)
|
|
|
|
def set_tabs(self, style):
|
|
if isinstance(style.tab_size, int):
|
|
layout = Layout(
|
|
context=self.context, font_size=style.font_size,
|
|
style=style)
|
|
layout.set_text(' ' * style.tab_size)
|
|
line, = layout.iter_lines()
|
|
width, _ = get_size(line, style)
|
|
width = int(round(width))
|
|
else:
|
|
width = int(style.tab_size.value)
|
|
# TODO: 0 is not handled correctly by Pango
|
|
array = ffi.gc(
|
|
pango.pango_tab_array_new_with_positions(
|
|
1, True, pango.PANGO_TAB_LEFT, width or 1),
|
|
pango.pango_tab_array_free)
|
|
pango.pango_layout_set_tabs(self.layout, array)
|
|
|
|
|
|
class FontMetrics(object):
|
|
def __init__(self, context, font, language):
|
|
self.metrics = ffi.gc(
|
|
pango.pango_context_get_metrics(context, font, language),
|
|
pango.pango_font_metrics_unref)
|
|
|
|
def __dir__(self):
|
|
return ['ascent', 'descent',
|
|
'approximate_char_width', 'approximate_digit_width',
|
|
'underline_thickness', 'underline_position',
|
|
'strikethrough_thickness', 'strikethrough_position']
|
|
|
|
def __getattr__(self, key):
|
|
if key in dir(self):
|
|
return units_to_double(
|
|
getattr(pango, 'pango_font_metrics_get_' + key)(self.metrics))
|
|
|
|
|
|
def get_font_features(
|
|
font_kerning='normal', font_variant_ligatures='normal',
|
|
font_variant_position='normal', font_variant_caps='normal',
|
|
font_variant_numeric='normal', font_variant_alternates='normal',
|
|
font_variant_east_asian='normal', font_feature_settings='normal'):
|
|
"""Get the font features from the different properties in style.
|
|
|
|
See https://www.w3.org/TR/css-fonts-3/#feature-precedence
|
|
|
|
"""
|
|
features = {}
|
|
ligature_keys = {
|
|
'common-ligatures': ['liga', 'clig'],
|
|
'historical-ligatures': ['hlig'],
|
|
'discretionary-ligatures': ['dlig'],
|
|
'contextual': ['calt']}
|
|
caps_keys = {
|
|
'small-caps': ['smcp'],
|
|
'all-small-caps': ['c2sc', 'smcp'],
|
|
'petite-caps': ['pcap'],
|
|
'all-petite-caps': ['c2pc', 'pcap'],
|
|
'unicase': ['unic'],
|
|
'titling-caps': ['titl']}
|
|
numeric_keys = {
|
|
'lining-nums': 'lnum',
|
|
'oldstyle-nums': 'onum',
|
|
'proportional-nums': 'pnum',
|
|
'tabular-nums': 'tnum',
|
|
'diagonal-fractions': 'frac',
|
|
'stacked-fractions': 'afrc',
|
|
'ordinal': 'ordn',
|
|
'slashed-zero': 'zero'}
|
|
east_asian_keys = {
|
|
'jis78': 'jp78',
|
|
'jis83': 'jp83',
|
|
'jis90': 'jp90',
|
|
'jis04': 'jp04',
|
|
'simplified': 'smpl',
|
|
'traditional': 'trad',
|
|
'full-width': 'fwid',
|
|
'proportional-width': 'pwid',
|
|
'ruby': 'ruby'}
|
|
|
|
# Step 1: getting the default, we rely on Pango for this
|
|
# Step 2: @font-face font-variant, done in fonts.add_font_face
|
|
# Step 3: @font-face font-feature-settings, done in fonts.add_font_face
|
|
|
|
# Step 4: font-variant and OpenType features
|
|
|
|
if font_kerning != 'auto':
|
|
features['kern'] = int(font_kerning == 'normal')
|
|
|
|
if font_variant_ligatures == 'none':
|
|
for keys in ligature_keys.values():
|
|
for key in keys:
|
|
features[key] = 0
|
|
elif font_variant_ligatures != 'normal':
|
|
for ligature_type in font_variant_ligatures:
|
|
value = 1
|
|
if ligature_type.startswith('no-'):
|
|
value = 0
|
|
ligature_type = ligature_type[3:]
|
|
for key in ligature_keys[ligature_type]:
|
|
features[key] = value
|
|
|
|
if font_variant_position == 'sub':
|
|
# TODO: the specification asks for additional checks
|
|
# https://www.w3.org/TR/css-fonts-3/#font-variant-position-prop
|
|
features['subs'] = 1
|
|
elif font_variant_position == 'super':
|
|
features['sups'] = 1
|
|
|
|
if font_variant_caps != 'normal':
|
|
# TODO: the specification asks for additional checks
|
|
# https://www.w3.org/TR/css-fonts-3/#font-variant-caps-prop
|
|
for key in caps_keys[font_variant_caps]:
|
|
features[key] = 1
|
|
|
|
if font_variant_numeric != 'normal':
|
|
for key in font_variant_numeric:
|
|
features[numeric_keys[key]] = 1
|
|
|
|
if font_variant_alternates != 'normal':
|
|
# TODO: support other values
|
|
# See https://www.w3.org/TR/css-fonts-3/#font-variant-caps-prop
|
|
if font_variant_alternates == 'historical-forms':
|
|
features['hist'] = 1
|
|
|
|
if font_variant_east_asian != 'normal':
|
|
for key in font_variant_east_asian:
|
|
features[east_asian_keys[key]] = 1
|
|
|
|
# Step 5: incompatible non-OpenType features, already handled by Pango
|
|
|
|
# Step 6: font-feature-settings
|
|
|
|
if font_feature_settings != 'normal':
|
|
features.update(dict(font_feature_settings))
|
|
|
|
return features
|
|
|
|
|
|
def create_layout(text, style, context, max_width):
|
|
"""Return an opaque Pango layout with default Pango line-breaks.
|
|
|
|
: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.
|
|
|
|
"""
|
|
text_wrap = style.white_space in ('normal', 'pre-wrap', 'pre-line')
|
|
if not text_wrap:
|
|
max_width = None
|
|
|
|
layout = Layout(context, style.font_size, style)
|
|
layout.set_text(text)
|
|
|
|
# Make sure that max_width * Pango.SCALE == max_width * 1024 fits in a
|
|
# signed integer. Treat bigger values same as None: unconstrained width.
|
|
if max_width is not None and max_width < 2 ** 21:
|
|
pango.pango_layout_set_width(
|
|
layout.layout, units_from_double(max_width))
|
|
|
|
text_bytes = layout.text_bytes
|
|
|
|
# Word and letter spacings
|
|
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):
|
|
letter_spacing = units_from_double(letter_spacing)
|
|
space_spacing = units_from_double(word_spacing) + letter_spacing
|
|
attr_list = pango.pango_attr_list_new()
|
|
|
|
def add_attr(start, end, spacing):
|
|
# TODO: attributes should be freed
|
|
attr = pango.pango_attr_letter_spacing_new(spacing)
|
|
attr.start_index, attr.end_index = start, end
|
|
pango.pango_attr_list_insert(attr_list, attr)
|
|
|
|
add_attr(0, len(text_bytes) + 1, letter_spacing)
|
|
position = text_bytes.find(b' ')
|
|
while position != -1:
|
|
add_attr(position, position + 1, space_spacing)
|
|
position = text_bytes.find(b' ', position + 1)
|
|
|
|
pango.pango_layout_set_attributes(layout.layout, attr_list)
|
|
pango.pango_attr_list_unref(attr_list)
|
|
|
|
features = get_font_features(
|
|
style.font_kerning, style.font_variant_ligatures,
|
|
style.font_variant_position, style.font_variant_caps,
|
|
style.font_variant_numeric, style.font_variant_alternates,
|
|
style.font_variant_east_asian, style.font_feature_settings)
|
|
if features:
|
|
features = ','.join(
|
|
('%s %i' % (key, value)) for key, value in features.items())
|
|
|
|
# TODO: attributes should be freed.
|
|
# In the meantime, keep a cache to avoid leaking too many of them.
|
|
attr = PANGO_ATTR_FONT_FEATURES_CACHE.get(features)
|
|
if attr is None:
|
|
try:
|
|
attr = pango.pango_attr_font_features_new(
|
|
features.encode('ascii'))
|
|
except AttributeError:
|
|
LOGGER.warning(
|
|
'OpenType features are not available with Pango < 1.38')
|
|
else:
|
|
PANGO_ATTR_FONT_FEATURES_CACHE[features] = attr
|
|
if attr is not None:
|
|
attr_list = pango.pango_attr_list_new()
|
|
pango.pango_attr_list_insert(attr_list, attr)
|
|
pango.pango_layout_set_attributes(layout.layout, attr_list)
|
|
|
|
# Tabs width
|
|
if style.tab_size != 8: # Default Pango value is 8
|
|
layout.set_tabs(style)
|
|
|
|
return layout
|
|
|
|
|
|
def split_first_line(text, style, context, max_width, line_width):
|
|
"""Fit as much as possible in the available width for one line of text.
|
|
|
|
Return ``(layout, length, resume_at, width, height, baseline)``.
|
|
|
|
``layout``: a pango Layout with the first line
|
|
``length``: length in UTF-8 bytes 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.
|
|
``width``: width in pixels of the first line
|
|
``height``: height in pixels of the first line
|
|
``baseline``: baseline in pixels of the first line
|
|
|
|
"""
|
|
# See https://www.w3.org/TR/css-text-3/#white-space-property
|
|
text_wrap = style.white_space in ('normal', 'pre-wrap', 'pre-line')
|
|
space_collapse = style.white_space in ('normal', 'nowrap', 'pre-line')
|
|
|
|
if not text_wrap:
|
|
max_width = None
|
|
|
|
# Step #1: Get a draft layout with the first line
|
|
layout = create_layout(text, style, context, max_width)
|
|
lines = layout.iter_lines()
|
|
first_line = next(lines, None)
|
|
second_line = next(lines, None)
|
|
resume_at = None if second_line is None else second_line.start_index
|
|
|
|
# Step #2: Don't hyphenize when it's not needed
|
|
if max_width is None:
|
|
# The first line can take all the place needed
|
|
return first_line_metrics(
|
|
first_line, text, layout, resume_at, space_collapse, style)
|
|
first_line_width, _ = get_size(first_line, style)
|
|
if second_line is None and first_line_width <= max_width:
|
|
# The first line fits in the available width
|
|
return first_line_metrics(
|
|
first_line, text, layout, resume_at, space_collapse, style)
|
|
|
|
# Step #3: Try to put the first word of the second line on the first line
|
|
# https://mail.gnome.org/archives/gtk-i18n-list/2013-September/msg00006
|
|
# is a good thread related to this problem.
|
|
if first_line_width <= max_width:
|
|
# The first line may have been cut too early by Pango
|
|
second_line_index = second_line.start_index
|
|
first_line_text = utf8_slice(text, slice(second_line_index))
|
|
second_line_text = utf8_slice(text, slice(second_line_index, None))
|
|
else:
|
|
# The first word is longer than the line, try to hyphenize it
|
|
first_line_text = ''
|
|
second_line_text = text
|
|
|
|
next_word = second_line_text.split(' ', 1)[0]
|
|
if next_word:
|
|
if space_collapse:
|
|
# next_word might fit without a space afterwards
|
|
# only try when space collapsing is allowed
|
|
new_first_line_text = first_line_text + next_word
|
|
layout.set_text(new_first_line_text)
|
|
lines = layout.iter_lines()
|
|
first_line = next(lines, None)
|
|
second_line = next(lines, None)
|
|
first_line_width, _ = get_size(first_line, style)
|
|
if second_line is None and first_line_text:
|
|
# The next word fits in the first line, keep the layout
|
|
resume_at = len(new_first_line_text.encode('utf-8')) + 1
|
|
if resume_at == len(text.encode('utf-8')):
|
|
resume_at = None
|
|
return first_line_metrics(
|
|
first_line, text, layout, resume_at, space_collapse, style)
|
|
elif second_line:
|
|
# Text may have been split elsewhere by Pango earlier
|
|
resume_at = second_line.start_index
|
|
else:
|
|
resume_at = first_line.length + 1
|
|
elif first_line_text:
|
|
# We found something on the first line but we did not find a word on
|
|
# the next line, no need to hyphenate, we can keep the current layout
|
|
return first_line_metrics(
|
|
first_line, text, layout, resume_at, space_collapse, style)
|
|
|
|
# Step #4: Try to hyphenize
|
|
hyphens = style.hyphens
|
|
lang = style.lang and pyphen.language_fallback(style.lang)
|
|
total, left, right = style.hyphenate_limit_chars
|
|
hyphenated = False
|
|
soft_hyphen = u'\u00ad'
|
|
|
|
# Automatic hyphenation possible and next word is long enough
|
|
if hyphens != 'none' and len(next_word) >= total:
|
|
first_line_width, _ = get_size(first_line, style)
|
|
space = max_width - first_line_width
|
|
if style.hyphenate_limit_zone.unit == '%':
|
|
limit_zone = max_width * style.hyphenate_limit_zone.value / 100.
|
|
else:
|
|
limit_zone = style.hyphenate_limit_zone.value
|
|
|
|
if space > limit_zone or space < 0:
|
|
# Manual hyphenation: check that the line ends with a soft hyphen
|
|
# and add the missing hyphen
|
|
if hyphens == 'manual':
|
|
if first_line_text.endswith(soft_hyphen):
|
|
# The first line has been split on a soft hyphen
|
|
if u' ' in first_line_text:
|
|
first_line_text, next_word = (
|
|
first_line_text.rsplit(u' ', 1))
|
|
next_word = u' ' + next_word
|
|
layout.set_text(first_line_text)
|
|
lines = layout.iter_lines()
|
|
first_line = next(lines, None)
|
|
second_line = next(lines, None)
|
|
resume_at = len(
|
|
(first_line_text + u' ').encode('utf8'))
|
|
else:
|
|
first_line_text, next_word = u'', first_line_text
|
|
soft_hyphen_indexes = [
|
|
match.start() for match in
|
|
re.finditer(soft_hyphen, next_word)]
|
|
soft_hyphen_indexes.reverse()
|
|
dictionary_iterations = [
|
|
next_word[:i + 1] for i in soft_hyphen_indexes]
|
|
elif hyphens == 'auto' and lang:
|
|
# The next word does not fit, try hyphenation
|
|
dictionary_key = (lang, left, right, total)
|
|
dictionary = PYPHEN_DICTIONARY_CACHE.get(dictionary_key)
|
|
if dictionary is None:
|
|
dictionary = pyphen.Pyphen(
|
|
lang=lang, left=left, right=right)
|
|
PYPHEN_DICTIONARY_CACHE[dictionary_key] = dictionary
|
|
dictionary_iterations = [
|
|
start for start, end in dictionary.iterate(next_word)]
|
|
else:
|
|
dictionary_iterations = []
|
|
|
|
if dictionary_iterations:
|
|
for first_word_part in dictionary_iterations:
|
|
new_first_line_text = first_line_text + first_word_part
|
|
hyphenated_first_line_text = (
|
|
new_first_line_text + style.hyphenate_character)
|
|
new_layout = create_layout(
|
|
hyphenated_first_line_text, style, context, max_width)
|
|
new_lines = new_layout.iter_lines()
|
|
new_first_line = next(new_lines, None)
|
|
new_second_line = next(new_lines, None)
|
|
new_first_line_width, _ = get_size(new_first_line, style)
|
|
new_space = max_width - new_first_line_width
|
|
if new_second_line is None and (
|
|
new_space >= 0 or
|
|
first_word_part == dictionary_iterations[-1]):
|
|
hyphenated = True
|
|
layout = new_layout
|
|
first_line = new_first_line
|
|
second_line = new_second_line
|
|
resume_at = len(new_first_line_text.encode('utf8'))
|
|
if text[len(new_first_line_text)] == soft_hyphen:
|
|
resume_at += len(soft_hyphen.encode('utf8'))
|
|
break
|
|
|
|
if not hyphenated and not first_line_text:
|
|
# Recreate the layout with no max_width to be sure that
|
|
# we don't break inside the hyphenate-character string
|
|
hyphenated = True
|
|
layout.set_text(hyphenated_first_line_text)
|
|
pango.pango_layout_set_width(
|
|
layout.layout, units_from_double(-1))
|
|
lines = layout.iter_lines()
|
|
first_line = next(lines, None)
|
|
second_line = next(lines, None)
|
|
resume_at = len(new_first_line_text.encode('utf8'))
|
|
if text[len(first_line_text)] == soft_hyphen:
|
|
resume_at += len(soft_hyphen.encode('utf8'))
|
|
|
|
if not hyphenated and first_line_text.endswith(soft_hyphen):
|
|
# Recreate the layout with no max_width to be sure that
|
|
# we don't break inside the hyphenate-character string
|
|
hyphenated = True
|
|
hyphenated_first_line_text = (
|
|
first_line_text + style.hyphenate_character)
|
|
layout.set_text(hyphenated_first_line_text)
|
|
pango.pango_layout_set_width(
|
|
layout.layout, units_from_double(-1))
|
|
lines = layout.iter_lines()
|
|
first_line = next(lines, None)
|
|
second_line = next(lines, None)
|
|
resume_at = len(first_line_text.encode('utf8'))
|
|
|
|
# Step 5: Try to break word if it's too long for the line
|
|
overflow_wrap = style.overflow_wrap
|
|
first_line_width, _ = get_size(first_line, style)
|
|
space = max_width - first_line_width
|
|
# If we can break words and the first line is too long
|
|
if overflow_wrap == 'break-word' and space < 0:
|
|
# Is it really OK to remove hyphenation for word-break ?
|
|
hyphenated = False
|
|
# TODO: Modify code to preserve W3C condition:
|
|
# "Shaping characters are still shaped as if the word were not broken"
|
|
# The way new lines are processed in this function (one by one with no
|
|
# memory of the last) prevents shaping characters (arabic, for
|
|
# instance) from keeping their shape when wrapped on the next line with
|
|
# pango layout. Maybe insert Unicode shaping characters in text ?
|
|
layout.set_text(text)
|
|
pango.pango_layout_set_width(
|
|
layout.layout, units_from_double(max_width))
|
|
layout.set_wrap(PANGO_WRAP_MODE['WRAP_CHAR'])
|
|
temp_lines = layout.iter_lines()
|
|
next(temp_lines, None)
|
|
temp_second_line = next(temp_lines, None)
|
|
temp_second_line_index = (
|
|
len(text.encode('utf-8')) if temp_second_line is None
|
|
else temp_second_line.start_index)
|
|
# TODO: WRAP_CHAR is said to "wrap lines at character boundaries", but
|
|
# it doesn't. Looks like it tries to split at word boundaries and then
|
|
# at character boundaries if there's no enough space for a full word,
|
|
# just as WRAP_WORD_CHAR does. That's why we have to split this text
|
|
# twice. Find why. It may be related to the problem described in the
|
|
# link given in step #3.
|
|
first_line_text = utf8_slice(text, slice(temp_second_line_index))
|
|
layout.set_text(first_line_text)
|
|
lines = layout.iter_lines()
|
|
first_line = next(lines, None)
|
|
second_line = next(lines, None)
|
|
resume_at = (
|
|
first_line.length if second_line is None
|
|
else second_line.start_index)
|
|
|
|
return first_line_metrics(
|
|
first_line, text, layout, resume_at, space_collapse, style, hyphenated,
|
|
style.hyphenate_character)
|
|
|
|
|
|
def line_widths(text, style, context, width):
|
|
"""Return the width for each line."""
|
|
layout = create_layout(text, style, context, width)
|
|
for line in layout.iter_lines():
|
|
width, _height = get_size(line, style)
|
|
yield width
|
|
|
|
|
|
def show_first_line(context, pango_layout, hinting):
|
|
"""Draw the given ``line`` to the Cairo ``context``."""
|
|
context = ffi.cast('cairo_t *', context._pointer)
|
|
if hinting:
|
|
pangocairo.pango_cairo_update_layout(context, pango_layout.layout)
|
|
# Set an infinite width as we don't want to break lines when drawing, the
|
|
# lines have already been split and the size may differ for example because
|
|
# of hinting.
|
|
pango.pango_layout_set_width(pango_layout.layout, -1)
|
|
pangocairo.pango_cairo_show_layout_line(
|
|
context, next(pango_layout.iter_lines()))
|