summaryrefslogtreecommitdiff
path: root/pango/break.c
blob: 3dc0465b070f3d0330a77bd9173159d91e16c9f0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
/* Pango
 * break.c:
 *
 * Copyright (C) 1999 Red Hat Software
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include "pango.h"
#include "pango-modules.h"

/**
 * pango_break:
 * @text:      the text to process
 * @length:    the length (in bytes) of @text
 * @analysis:  #PangoAnalysis structure from PangoItemize
 * @attrs:     an array to store character information in
 *
 * Determines possible line, word, and character breaks
 * for a string of Unicode text.
 */
void pango_break (const gchar   *text, 
		  gint           length, 
		  PangoAnalysis *analysis, 
		  PangoLogAttr  *attrs)
{
  /* Pseudo-implementation */

  const gchar *cur = text;
  gint i = 0;
  gunichar wc;
  
  while (*cur && cur - text < length)
    {
      wc = g_utf8_get_char (cur);
      if (wc == (gunichar)-1)
	break;			/* FIXME: ERROR */

      attrs[i].is_white = (wc == ' ' || wc == '\t' || wc == '\n' || wc == 0x200b) ? 1 : 0;
      attrs[i].is_break = i == 0 || attrs[i-1].is_white || attrs[i].is_white;
      attrs[i].is_char_stop = 1;
      attrs[i].is_word_stop = ((i == 0) || attrs[i-1].is_white) && !attrs[i].is_white;
      
      i++;
      cur = g_utf8_next_char (cur);
    }
}

/**
 * pango_get_log_attrs:
 * @text: text to process
 * @length: length in bytes of @text
 * @level: embedding level, or -1 if unknown
 * @language: language code
 * @log_attrs: array with one PangoLogAttr per character in @text, to be filled in
 *
 * Computes a PangoLogAttr for each character in @text
 */
void
pango_get_log_attrs (const char    *text,
                     int            length,
                     int            level,
                     const char    *language,
                     PangoLogAttr  *log_attrs)
{
  int n_chars;
  PangoMap *lang_map;
  int chars_broken;
  const char *pos;
  const char *end;
  PangoEngineLang* range_engine;
  const char *range_start;
  int chars_in_range;
  static guint engine_type_id = 0;
  static guint render_type_id = 0;  
  PangoAnalysis analysis = { NULL, NULL, NULL, 0 };

  analysis.level = level;
  
  g_return_if_fail (length == 0 || text != NULL);
  g_return_if_fail (log_attrs != NULL);
  
  if (length == 0)
    return;
  
  if (engine_type_id == 0)
    {
      engine_type_id = g_quark_from_static_string (PANGO_ENGINE_TYPE_LANG);
      render_type_id = g_quark_from_static_string (PANGO_RENDER_TYPE_NONE);
    }

  n_chars = g_utf8_strlen (text, length);

  lang_map = pango_find_map (language, engine_type_id, render_type_id);
    
  range_start = text;
  range_engine = (PangoEngineLang*) pango_map_get_engine (lang_map,
                                                          g_utf8_get_char (text));
  analysis.lang_engine = range_engine;
  chars_broken = 0;
  chars_in_range = 1;
  
  end = text + length;
  pos = g_utf8_next_char (text);
  
  while (pos != end)
    {
      analysis.lang_engine =
        (PangoEngineLang*) pango_map_get_engine (lang_map,
                                                 g_utf8_get_char (pos));
      
      if (range_engine != analysis.lang_engine)
        {
          /* Engine has changed; do the breaking for the current range,
           * then start a new range.
           */
          pango_break (range_start,
                       pos - range_start,
                       &analysis,
                       log_attrs + chars_broken);

          chars_broken += chars_in_range;
          
          range_start = pos;
          range_engine = analysis.lang_engine;
          chars_in_range = 1;
        }
      else
        {
          chars_in_range += 1;
        }
      
      pos = g_utf8_next_char (pos);
    }
    
    g_assert (chars_in_range > 0);
    g_assert (range_start != end);
    g_assert (pos == end);
    g_assert (range_engine == analysis.lang_engine);
    
    pango_break (range_start,
                 end - range_start,
                 &analysis,
                 log_attrs + chars_broken);
}