summaryrefslogtreecommitdiff
path: root/gtk/gtktextsegment.c
blob: a202ab603cddc731e6ac9d701cb7d3e2ebb4d667 (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
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
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
/*
 * gtktextsegment.c --
 *
 * Code for segments in general, and toggle/char segments in particular.
 *
 * Copyright (c) 1992-1994 The Regents of the University of California.
 * Copyright (c) 1994-1995 Sun Microsystems, Inc.
 * Copyright (c) 2000      Red Hat, Inc.
 * Tk -> Gtk port by Havoc Pennington <hp@redhat.com>
 *
 * This software is copyrighted by the Regents of the University of
 * California, Sun Microsystems, Inc., and other parties.  The
 * following terms apply to all files associated with the software
 * unless explicitly disclaimed in individual files.
 *
 * The authors hereby grant permission to use, copy, modify,
 * distribute, and license this software and its documentation for any
 * purpose, provided that existing copyright notices are retained in
 * all copies and that this notice is included verbatim in any
 * distributions. No written agreement, license, or royalty fee is
 * required for any of the authorized uses.  Modifications to this
 * software may be copyrighted by their authors and need not follow
 * the licensing terms described here, provided that the new terms are
 * clearly indicated on the first page of each file where they apply.
 *
 * IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY
 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
 * DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION,
 * OR ANY DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
 * NON-INFRINGEMENT.  THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS,
 * AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
 * MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * GOVERNMENT USE: If you are acquiring this software on behalf of the
 * U.S. government, the Government shall have only "Restricted Rights"
 * in the software and related documentation as defined in the Federal
 * Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2).  If you
 * are acquiring the software on behalf of the Department of Defense,
 * the software shall be classified as "Commercial Computer Software"
 * and the Government shall have only "Restricted Rights" as defined
 * in Clause 252.227-7013 (c) (1) of DFARs.  Notwithstanding the
 * foregoing, the authors grant the U.S. Government and others acting
 * in its behalf permission to use and distribute the software in
 * accordance with the terms specified in this license.
 *
 */

#include "config.h"
#include "gtktextbtree.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "gtktexttag.h"
#include "gtktexttagtable.h"
#include "gtktextlayoutprivate.h"
#include "gtktextiterprivate.h"
#include "gtkdebug.h"

/*
 *--------------------------------------------------------------
 *
 * split_segment --
 *
 *      This procedure is called before adding or deleting
 *      segments.  It does three things: (a) it finds the segment
 *      containing iter;  (b) if there are several such
 *      segments (because some segments have zero length) then
 *      it picks the first segment that does not have left
 *      gravity;  (c) if the index refers to the middle of
 *      a segment then it splits the segment so that the
 *      index now refers to the beginning of a segment.
 *
 * Results:
 *      The return value is a pointer to the segment just
 *      before the segment corresponding to iter (as
 *      described above).  If the segment corresponding to
 *      iter is the first in its line then the return
 *      value is NULL.
 *
 * Side effects:
 *      The segment referred to by iter is split unless
 *      iter refers to its first character.
 *
 *--------------------------------------------------------------
 */

GtkTextLineSegment*
gtk_text_line_segment_split (const GtkTextIter *iter)
{
  GtkTextLineSegment *prev, *seg;
  GtkTextBTree *tree;
  GtkTextLine *line;
  int count;

  line = _gtk_text_iter_get_text_line (iter);
  tree = _gtk_text_iter_get_btree (iter);

  count = gtk_text_iter_get_line_index (iter);

  if (GTK_DEBUG_CHECK (TEXT))
    _gtk_text_iter_check (iter);
  
  prev = NULL;
  seg = line->segments;

  while (seg != NULL)
    {
      if (seg->byte_count > count)
        {
          if (count == 0)
            {
              return prev;
            }
          else
            {
              g_assert (count != seg->byte_count);
              g_assert (seg->byte_count > 0);

              _gtk_text_btree_segments_changed (tree);

              seg = (*seg->type->splitFunc)(seg, count);

              if (prev == NULL)
                line->segments = seg;
              else
                prev->next = seg;

              return seg;
            }
        }
      else if ((seg->byte_count == 0) && (count == 0)
               && !seg->type->leftGravity)
        {
          return prev;
        }

      count -= seg->byte_count;
      prev = seg;
      seg = seg->next;
    }
  g_error ("split_segment reached end of line!");
  return NULL;
}


/*
 * Macros that determine how much space to allocate for new segments:
 */

#define CSEG_SIZE(chars) ((unsigned) (G_STRUCT_OFFSET (GtkTextLineSegment, body) \
        + 1 + (chars)))
#define TSEG_SIZE ((unsigned) (G_STRUCT_OFFSET (GtkTextLineSegment, body) \
        + sizeof (GtkTextToggleBody)))

/*
 * Type functions
 */

static void
char_segment_self_check (GtkTextLineSegment *seg)
{
  /* This function checks the segment itself, but doesn't
     assume the segment has been validly inserted into
     the btree. */

  g_assert (seg != NULL);

  if (seg->byte_count <= 0)
    {
      g_error ("segment has size <= 0");
    }

  if (strlen (seg->body.chars) != seg->byte_count)
    {
      g_error ("segment has wrong size");
    }

  if (g_utf8_strlen (seg->body.chars, seg->byte_count) != seg->char_count)
    {
      g_error ("char segment has wrong character count");
    }
}

GtkTextLineSegment*
_gtk_char_segment_new (const char *text, guint len)
{
  GtkTextLineSegment *seg;

  g_assert (gtk_text_byte_begins_utf8_char (text));

  seg = g_slice_alloc (CSEG_SIZE (len));
  seg->type = (GtkTextLineSegmentClass *)&gtk_text_char_type;
  seg->next = NULL;
  seg->byte_count = len;
  memcpy (seg->body.chars, text, len);
  seg->body.chars[len] = '\0';

  seg->char_count = g_utf8_strlen (seg->body.chars, seg->byte_count);

  if (GTK_DEBUG_CHECK (TEXT))
    char_segment_self_check (seg);

  return seg;
}

GtkTextLineSegment*
_gtk_char_segment_new_from_two_strings (const char *text1, 
					guint        len1, 
					guint        chars1,
                                        const char *text2, 
					guint        len2, 
					guint        chars2)
{
  GtkTextLineSegment *seg;

  g_assert (gtk_text_byte_begins_utf8_char (text1));
  g_assert (gtk_text_byte_begins_utf8_char (text2));

  seg = g_slice_alloc (CSEG_SIZE (len1+len2));
  seg->type = &gtk_text_char_type;
  seg->next = NULL;
  seg->byte_count = len1 + len2;
  memcpy (seg->body.chars, text1, len1);
  memcpy (seg->body.chars + len1, text2, len2);
  seg->body.chars[len1+len2] = '\0';

  seg->char_count = chars1 + chars2;

  if (GTK_DEBUG_CHECK (TEXT))
    char_segment_self_check (seg);

  return seg;
}

static void
_gtk_char_segment_free (GtkTextLineSegment *seg)
{
  if (seg == NULL)
    return;

  g_assert (seg->type == &gtk_text_char_type);

  g_slice_free1 (CSEG_SIZE (seg->byte_count), seg);
}

/*
 *--------------------------------------------------------------
 *
 * char_segment_split_func --
 *
 *      This procedure implements splitting for character segments.
 *
 * Results:
 *      The return value is a pointer to a chain of two segments
 *      that have the same characters as segPtr except split
 *      among the two segments.
 *
 * Side effects:
 *      Storage for segPtr is freed.
 *
 *--------------------------------------------------------------
 */

static GtkTextLineSegment *
char_segment_split_func (GtkTextLineSegment *seg, int index)
{
  GtkTextLineSegment *new1, *new2;

  g_assert (index < seg->byte_count);

  if (GTK_DEBUG_CHECK (TEXT))
    {
      char_segment_self_check (seg);
    }

  new1 = _gtk_char_segment_new (seg->body.chars, index);
  new2 = _gtk_char_segment_new (seg->body.chars + index, seg->byte_count - index);

  g_assert (gtk_text_byte_begins_utf8_char (new1->body.chars));
  g_assert (gtk_text_byte_begins_utf8_char (new2->body.chars));
  g_assert (new1->byte_count + new2->byte_count == seg->byte_count);
  g_assert (new1->char_count + new2->char_count == seg->char_count);

  new1->next = new2;
  new2->next = seg->next;

  if (GTK_DEBUG_CHECK (TEXT))
    {
      char_segment_self_check (new1);
      char_segment_self_check (new2);
    }

  _gtk_char_segment_free (seg);
  return new1;
}

/*
 *--------------------------------------------------------------
 *
 * char_segment_cleanup_func --
 *
 *      This procedure merges adjacent character segments into
 *      a single character segment, if possible.
 *
 * Arguments:
 *      segPtr: Pointer to the first of two adjacent segments to
 *              join.
 *      line:   Line containing segments (not used).
 *
 * Results:
 *      The return value is a pointer to the first segment in
 *      the (new) list of segments that used to start with segPtr.
 *
 * Side effects:
 *      Storage for the segments may be allocated and freed.
 *
 *--------------------------------------------------------------
 */

        /* ARGSUSED */
static GtkTextLineSegment *
char_segment_cleanup_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
{
  GtkTextLineSegment *segPtr2, *newPtr;

  if (GTK_DEBUG_CHECK (TEXT))
    char_segment_self_check (segPtr);

  segPtr2 = segPtr->next;
  if ((segPtr2 == NULL) || (segPtr2->type != &gtk_text_char_type))
    {
      return segPtr;
    }

  newPtr =
    _gtk_char_segment_new_from_two_strings (segPtr->body.chars, 
					    segPtr->byte_count,
					    segPtr->char_count,
                                            segPtr2->body.chars, 
					    segPtr2->byte_count,
					    segPtr2->char_count);

  newPtr->next = segPtr2->next;

  if (GTK_DEBUG_CHECK (TEXT))
    char_segment_self_check (newPtr);

  _gtk_char_segment_free (segPtr);
  _gtk_char_segment_free (segPtr2);
  return newPtr;
}

/*
 *--------------------------------------------------------------
 *
 * char_segment_delete_func --
 *
 *      This procedure is invoked to delete a character segment.
 *
 * Arguments:
 *      segPtr   : Segment to delete
 *      line     : Line containing segment
 *      treeGone : Non-zero means the entire tree is being
 *                 deleted, so everything must get cleaned up.
 *
 * Results:
 *      Always returns 0 to indicate that the segment was deleted.
 *
 * Side effects:
 *      Storage for the segment is freed.
 *
 *--------------------------------------------------------------
 */

        /* ARGSUSED */
static int
char_segment_delete_func (GtkTextLineSegment *segPtr, GtkTextLine *line, int treeGone)
{
  _gtk_char_segment_free (segPtr);
  return 0;
}

/*
 *--------------------------------------------------------------
 *
 * char_segment_check_func --
 *
 *      This procedure is invoked to perform consistency checks
 *      on character segments.
 *
 * Arguments:
 *      segPtr : Segment to check
 *      line   : Line containing segment
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      If the segment isn’t inconsistent then the procedure
 *      g_errors.
 *
 *--------------------------------------------------------------
 */

        /* ARGSUSED */
static void
char_segment_check_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
{
  char_segment_self_check (segPtr);

  if (segPtr->next != NULL)
    {
      if (segPtr->next->type == &gtk_text_char_type)
        {
          g_error ("adjacent character segments weren't merged");
        }
    }
}

GtkTextLineSegment*
_gtk_toggle_segment_new (GtkTextTagInfo *info, gboolean on)
{
  GtkTextLineSegment *seg;

  seg = g_slice_alloc (TSEG_SIZE);

  seg->type = on ? &gtk_text_toggle_on_type : &gtk_text_toggle_off_type;

  seg->next = NULL;

  seg->byte_count = 0;
  seg->char_count = 0;

  seg->body.toggle.info = info;
  seg->body.toggle.inNodeCounts = 0;

  return seg;
}

void
_gtk_toggle_segment_free (GtkTextLineSegment *seg)
{
  if (seg == NULL)
    return;

  g_assert (seg->type == &gtk_text_toggle_on_type ||
            seg->type == &gtk_text_toggle_off_type);

  g_slice_free1 (TSEG_SIZE, seg);
}

/*
 *--------------------------------------------------------------
 *
 * toggle_segment_delete_func --
 *
 *      This procedure is invoked to delete toggle segments.
 *
 * Arguments:
 *      segPtr   : Segment to check
 *      line     : Line containing segment
 *      treeGone : Non-zero means the entire tree is being
 *                 deleted so everything must get cleaned up
 *
 * Results:
 *      Returns 1 to indicate that the segment may not be deleted,
 *      unless the entire B-tree is going away.
 *
 * Side effects:
 *      If the tree is going away then the toggle’s memory is
 *      freed;  otherwise the toggle counts in GtkTextBTreeNodes above the
 *      segment get updated.
 *
 *--------------------------------------------------------------
 */

static int
toggle_segment_delete_func (GtkTextLineSegment *segPtr, GtkTextLine *line, int treeGone)
{
  if (treeGone)
    {
      _gtk_toggle_segment_free (segPtr);
      return 0;
    }

  /*
   * This toggle is in the middle of a range of characters that's
   * being deleted.  Refuse to die.  We'll be moved to the end of
   * the deleted range and our cleanup procedure will be called
   * later.  Decrement GtkTextBTreeNode toggle counts here, and set a flag
   * so we'll re-increment them in the cleanup procedure.
   */

  if (segPtr->body.toggle.inNodeCounts)
    {
      _gtk_change_node_toggle_count (line->parent,
                                     segPtr->body.toggle.info, -1);
      segPtr->body.toggle.inNodeCounts = 0;
    }
  return 1;
}

/*
 *--------------------------------------------------------------
 *
 * toggle_segment_cleanup_func --
 *
 *      This procedure is called when a toggle is part of a line that's
 *      been modified in some way.  It’s invoked after the
 *      modifications are complete.
 *
 * Arguments:
 *      segPtr : Segment to check
 *      line   : Line that now contains segment
 *
 * Results:
 *      The return value is the head segment in a new list
 *      that is to replace the tail of the line that used to
 *      start at segPtr.  This allows the procedure to delete
 *      or modify segPtr.
 *
 * Side effects:
 *      Toggle counts in the GtkTextBTreeNodes above the new line will be
 *      updated if they’re not already.  Toggles may be collapsed
 *      if there are duplicate toggles at the same position.
 *
 *--------------------------------------------------------------
 */

static GtkTextLineSegment *
toggle_segment_cleanup_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
{
  GtkTextLineSegment *segPtr2, *prevPtr;
  int counts;

  /*
   * If this is a toggle-off segment, look ahead through the next
   * segments to see if there's a toggle-on segment for the same tag
   * before any segments with non-zero size.  If so then the two
   * toggles cancel each other;  remove them both.
   */

  if (segPtr->type == &gtk_text_toggle_off_type)
    {
      for (prevPtr = segPtr, segPtr2 = prevPtr->next;
           (segPtr2 != NULL) && (segPtr2->byte_count == 0);
           prevPtr = segPtr2, segPtr2 = prevPtr->next)
        {
          if (segPtr2->type != &gtk_text_toggle_on_type)
            {
              continue;
            }
          if (segPtr2->body.toggle.info != segPtr->body.toggle.info)
            {
              continue;
            }
          counts = segPtr->body.toggle.inNodeCounts
            + segPtr2->body.toggle.inNodeCounts;
          if (counts != 0)
            {
              _gtk_change_node_toggle_count (line->parent,
                                             segPtr->body.toggle.info, -counts);
            }
          prevPtr->next = segPtr2->next;
          _gtk_toggle_segment_free (segPtr2);
          segPtr2 = segPtr->next;
          _gtk_toggle_segment_free (segPtr);
          return segPtr2;
        }
    }

  if (!segPtr->body.toggle.inNodeCounts)
    {
      _gtk_change_node_toggle_count (line->parent,
                                     segPtr->body.toggle.info, 1);
      segPtr->body.toggle.inNodeCounts = 1;
    }
  return segPtr;
}

/*
 *--------------------------------------------------------------
 *
 * toggle_segment_line_change_func --
 *
 *      This procedure is invoked when a toggle segment is about
 *      to move from one line to another.
 *
 * Arguments:
 *      segPtr : Segment to check
 *      line   : Line that used to contain segment
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Toggle counts are decremented in the GtkTextBTreeNodes above the line.
 *
 *--------------------------------------------------------------
 */

static void
toggle_segment_line_change_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
{
  if (segPtr->body.toggle.inNodeCounts)
    {
      _gtk_change_node_toggle_count (line->parent,
                                     segPtr->body.toggle.info, -1);
      segPtr->body.toggle.inNodeCounts = 0;
    }
}

/*
 * Virtual tables
 */


const GtkTextLineSegmentClass gtk_text_char_type = {
  "character",                          /* name */
  0,                                            /* leftGravity */
  char_segment_split_func,                              /* splitFunc */
  char_segment_delete_func,                             /* deleteFunc */
  char_segment_cleanup_func,                            /* cleanupFunc */
  NULL,         /* lineChangeFunc */
  char_segment_check_func                               /* checkFunc */
};

/*
 * Type record for segments marking the beginning of a tagged
 * range:
 */

const GtkTextLineSegmentClass gtk_text_toggle_on_type = {
  "toggleOn",                                   /* name */
  0,                                            /* leftGravity */
  NULL,                 /* splitFunc */
  toggle_segment_delete_func,                           /* deleteFunc */
  toggle_segment_cleanup_func,                          /* cleanupFunc */
  toggle_segment_line_change_func,                      /* lineChangeFunc */
  _gtk_toggle_segment_check_func                        /* checkFunc */
};

/*
 * Type record for segments marking the end of a tagged
 * range:
 */

const GtkTextLineSegmentClass gtk_text_toggle_off_type = {
  "toggleOff",                          /* name */
  1,                                            /* leftGravity */
  NULL,                 /* splitFunc */
  toggle_segment_delete_func,                           /* deleteFunc */
  toggle_segment_cleanup_func,                          /* cleanupFunc */
  toggle_segment_line_change_func,                      /* lineChangeFunc */
  _gtk_toggle_segment_check_func                        /* checkFunc */
};