File: pango-tabs.c

package info (click to toggle)
pango1.0 1.42.4-8~deb10u1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 9,564 kB
  • sloc: ansic: 42,694; sh: 4,360; makefile: 1,075; python: 305; perl: 56; cpp: 20
file content (378 lines) | stat: -rw-r--r-- 9,568 bytes parent folder | download | duplicates (3)
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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
/* Pango
 * pango-tabs.c: Tab-related stuff
 *
 * Copyright (C) 2000 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.
 */

/**
 * SECTION:tab-stops
 * @short_description:Structures for storing tab stops
 * @title:Tab Stops
 *
 * Functions in this section are used to deal with #PangoTabArray objects
 * that can be used to set tab stop positions in a #PangoLayout.
 */
#include "config.h"
#include "pango-tabs.h"
#include "pango-impl-utils.h"
#include <string.h>

typedef struct _PangoTab PangoTab;

struct _PangoTab
{
  gint location;	        /* Offset in pixels of this tab stop
				 * from the left margin of the text.
				 */
  PangoTabAlign alignment;      /* Where the tab stop appears relative
				 * to the text.
				 */
};

/**
 * PangoTabArray:
 *
 * A #PangoTabArray struct contains an array
 * of tab stops. Each tab stop has an alignment and a position.
 */
struct _PangoTabArray
{
  gint size;
  gint allocated;
  gboolean positions_in_pixels;
  PangoTab *tabs;
};

static void
init_tabs (PangoTabArray *array, gint start, gint end)
{
  while (start < end)
    {
      array->tabs[start].location = 0;
      array->tabs[start].alignment = PANGO_TAB_LEFT;
      ++start;
    }
}

/**
 * pango_tab_array_new:
 * @initial_size: Initial number of tab stops to allocate, can be 0
 * @positions_in_pixels: whether positions are in pixel units
 *
 * Creates an array of @initial_size tab stops. Tab stops are specified in
 * pixel units if @positions_in_pixels is %TRUE, otherwise in Pango
 * units. All stops are initially at position 0.
 *
 * Return value: the newly allocated #PangoTabArray, which should
 *               be freed with pango_tab_array_free().
 **/
PangoTabArray*
pango_tab_array_new (gint initial_size,
		     gboolean positions_in_pixels)
{
  PangoTabArray *array;

  g_return_val_if_fail (initial_size >= 0, NULL);

  /* alloc enough to treat array->tabs as an array of length
   * size, though it's declared as an array of length 1.
   * If we allowed tab array resizing we'd need to drop this
   * optimization.
   */
  array = g_slice_new (PangoTabArray);
  array->size = initial_size;
  array->allocated = initial_size;

  if (array->allocated > 0)
    {
      array->tabs = g_new (PangoTab, array->allocated);
      init_tabs (array, 0, array->allocated);
    }
  else
    array->tabs = NULL;

  array->positions_in_pixels = positions_in_pixels;

  return array;
}

/**
 * pango_tab_array_new_with_positions:
 * @size: number of tab stops in the array
 * @positions_in_pixels: whether positions are in pixel units
 * @first_alignment: alignment of first tab stop
 * @first_position: position of first tab stop
 * @...: additional alignment/position pairs
 *
 * This is a convenience function that creates a #PangoTabArray
 * and allows you to specify the alignment and position of each
 * tab stop. You <emphasis>must</emphasis> provide an alignment
 * and position for @size tab stops.
 *
 * Return value: the newly allocated #PangoTabArray, which should
 *               be freed with pango_tab_array_free().
 **/
PangoTabArray  *
pango_tab_array_new_with_positions (gint           size,
				    gboolean       positions_in_pixels,
				    PangoTabAlign  first_alignment,
				    gint           first_position,
				    ...)
{
  PangoTabArray *array;
  va_list args;
  int i;

  g_return_val_if_fail (size >= 0, NULL);

  array = pango_tab_array_new (size, positions_in_pixels);

  if (size == 0)
    return array;

  array->tabs[0].alignment = first_alignment;
  array->tabs[0].location = first_position;

  if (size == 1)
    return array;

  va_start (args, first_position);

  i = 1;
  while (i < size)
    {
      PangoTabAlign align = va_arg (args, PangoTabAlign);
      int pos = va_arg (args, int);

      array->tabs[i].alignment = align;
      array->tabs[i].location = pos;

      ++i;
    }

  va_end (args);

  return array;
}

G_DEFINE_BOXED_TYPE (PangoTabArray, pango_tab_array,
                     pango_tab_array_copy,
                     pango_tab_array_free);

/**
 * pango_tab_array_copy:
 * @src: #PangoTabArray to copy
 *
 * Copies a #PangoTabArray
 *
 * Return value: the newly allocated #PangoTabArray, which should
 *               be freed with pango_tab_array_free().
 **/
PangoTabArray*
pango_tab_array_copy (PangoTabArray *src)
{
  PangoTabArray *copy;

  g_return_val_if_fail (src != NULL, NULL);

  copy = pango_tab_array_new (src->size, src->positions_in_pixels);

  memcpy (copy->tabs, src->tabs, sizeof(PangoTab)*src->size);

  return copy;
}

/**
 * pango_tab_array_free:
 * @tab_array: a #PangoTabArray
 *
 * Frees a tab array and associated resources.
 *
 **/
void
pango_tab_array_free   (PangoTabArray *tab_array)
{
  g_return_if_fail (tab_array != NULL);

  g_free (tab_array->tabs);

  g_slice_free (PangoTabArray, tab_array);
}

/**
 * pango_tab_array_get_size:
 * @tab_array: a #PangoTabArray
 *
 * Gets the number of tab stops in @tab_array.
 *
 * Return value: the number of tab stops in the array.
 **/
gint
pango_tab_array_get_size (PangoTabArray *tab_array)
{
  g_return_val_if_fail (tab_array != NULL, 0);

  return tab_array->size;
}

/**
 * pango_tab_array_resize:
 * @tab_array: a #PangoTabArray
 * @new_size: new size of the array
 *
 * Resizes a tab array. You must subsequently initialize any tabs that
 * were added as a result of growing the array.
 *
 **/
void
pango_tab_array_resize (PangoTabArray *tab_array,
			gint           new_size)
{
  if (new_size > tab_array->allocated)
    {
      gint current_end = tab_array->allocated;

      /* Ratchet allocated size up above the index. */
      if (tab_array->allocated == 0)
	tab_array->allocated = 2;

      while (new_size > tab_array->allocated)
	tab_array->allocated = tab_array->allocated * 2;

      tab_array->tabs = g_renew (PangoTab, tab_array->tabs,
				 tab_array->allocated);

      init_tabs (tab_array, current_end, tab_array->allocated);
    }

  tab_array->size = new_size;
}

/**
 * pango_tab_array_set_tab:
 * @tab_array: a #PangoTabArray
 * @tab_index: the index of a tab stop
 * @alignment: tab alignment
 * @location: tab location in Pango units
 *
 * Sets the alignment and location of a tab stop.
 * @alignment must always be #PANGO_TAB_LEFT in the current
 * implementation.
 *
 **/
void
pango_tab_array_set_tab  (PangoTabArray *tab_array,
			  gint           tab_index,
			  PangoTabAlign  alignment,
			  gint           location)
{
  g_return_if_fail (tab_array != NULL);
  g_return_if_fail (tab_index >= 0);
  g_return_if_fail (alignment == PANGO_TAB_LEFT);
  g_return_if_fail (location >= 0);

  if (tab_index >= tab_array->size)
    pango_tab_array_resize (tab_array, tab_index + 1);

  tab_array->tabs[tab_index].alignment = alignment;
  tab_array->tabs[tab_index].location = location;
}

/**
 * pango_tab_array_get_tab:
 * @tab_array: a #PangoTabArray
 * @tab_index: tab stop index
 * @alignment: (out) (allow-none): location to store alignment, or %NULL
 * @location: (out) (allow-none): location to store tab position, or %NULL
 *
 * Gets the alignment and position of a tab stop.
 *
 **/
void
pango_tab_array_get_tab  (PangoTabArray *tab_array,
			  gint           tab_index,
			  PangoTabAlign *alignment,
			  gint          *location)
{
  g_return_if_fail (tab_array != NULL);
  g_return_if_fail (tab_index < tab_array->size);
  g_return_if_fail (tab_index >= 0);

  if (alignment)
    *alignment = tab_array->tabs[tab_index].alignment;

  if (location)
    *location = tab_array->tabs[tab_index].location;
}

/**
 * pango_tab_array_get_tabs:
 * @tab_array: a #PangoTabArray
 * @alignments: (out) (allow-none): location to store an array of tab
 *   stop alignments, or %NULL
 * @locations: (out) (allow-none) (array): location to store an array
 *   of tab positions, or %NULL
 *
 * If non-%NULL, @alignments and @locations are filled with allocated
 * arrays of length pango_tab_array_get_size(). You must free the
 * returned array.
 *
 **/
void
pango_tab_array_get_tabs (PangoTabArray *tab_array,
			  PangoTabAlign **alignments,
			  gint          **locations)
{
  gint i;

  g_return_if_fail (tab_array != NULL);

  if (alignments)
    *alignments = g_new (PangoTabAlign, tab_array->size);

  if (locations)
    *locations = g_new (gint, tab_array->size);

  i = 0;
  while (i < tab_array->size)
    {
      if (alignments)
	(*alignments)[i] = tab_array->tabs[i].alignment;
      if (locations)
	(*locations)[i] = tab_array->tabs[i].location;

      ++i;
    }
}

/**
 * pango_tab_array_get_positions_in_pixels:
 * @tab_array: a #PangoTabArray
 *
 * Returns %TRUE if the tab positions are in pixels, %FALSE if they are
 * in Pango units.
 *
 * Return value: whether positions are in pixels.
 **/
gboolean
pango_tab_array_get_positions_in_pixels (PangoTabArray *tab_array)
{
  g_return_val_if_fail (tab_array != NULL, FALSE);

  return tab_array->positions_in_pixels;
}