1 /* gtktextmark.c - mark segments
2 *
3 * Copyright (c) 1994 The Regents of the University of California.
4 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
5 * Copyright (c) 2000 Red Hat, Inc.
6 * Tk -> Gtk port by Havoc Pennington <hp@redhat.com>
7 *
8 * This software is copyrighted by the Regents of the University of
9 * California, Sun Microsystems, Inc., and other parties. The
10 * following terms apply to all files associated with the software
11 * unless explicitly disclaimed in individual files.
12 *
13 * The authors hereby grant permission to use, copy, modify,
14 * distribute, and license this software and its documentation for any
15 * purpose, provided that existing copyright notices are retained in
16 * all copies and that this notice is included verbatim in any
17 * distributions. No written agreement, license, or royalty fee is
18 * required for any of the authorized uses. Modifications to this
19 * software may be copyrighted by their authors and need not follow
20 * the licensing terms described here, provided that the new terms are
21 * clearly indicated on the first page of each file where they apply.
22 *
23 * IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY
24 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
25 * DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION,
26 * OR ANY DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED
27 * OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
30 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
31 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
32 * NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS,
33 * AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
34 * MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
35 *
36 * GOVERNMENT USE: If you are acquiring this software on behalf of the
37 * U.S. government, the Government shall have only "Restricted Rights"
38 * in the software and related documentation as defined in the Federal
39 * Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2). If you
40 * are acquiring the software on behalf of the Department of Defense,
41 * the software shall be classified as "Commercial Computer Software"
42 * and the Government shall have only "Restricted Rights" as defined
43 * in Clause 252.227-7013 (c) (1) of DFARs. Notwithstanding the
44 * foregoing, the authors grant the U.S. Government and others acting
45 * in its behalf permission to use and distribute the software in
46 * accordance with the terms specified in this license.
47 *
48 */
49
50 #define GTK_TEXT_USE_INTERNAL_UNSUPPORTED_API
51 #include "config.h"
52 #include "gtktextbtree.h"
53 #include "gtkprivate.h"
54 #include "gtkintl.h"
55
56
57 /**
58 * SECTION:gtktextmark
59 * @Short_description: A position in the buffer preserved across buffer modifications
60 * @Title: GtkTextMark
61 *
62 * You may wish to begin by reading the
63 * [text widget conceptual overview][TextWidget]
64 * which gives an overview of all the objects and data
65 * types related to the text widget and how they work together.
66 *
67 * A #GtkTextMark is like a bookmark in a text buffer; it preserves a position in
68 * the text. You can convert the mark to an iterator using
69 * gtk_text_buffer_get_iter_at_mark(). Unlike iterators, marks remain valid across
70 * buffer mutations, because their behavior is defined when text is inserted or
71 * deleted. When text containing a mark is deleted, the mark remains in the
72 * position originally occupied by the deleted text. When text is inserted at a
73 * mark, a mark with “left gravity” will be moved to the
74 * beginning of the newly-inserted text, and a mark with “right
75 * gravity” will be moved to the end.
76 *
77 * Note that “left” and “right” here refer to logical direction (left
78 * is the toward the start of the buffer); in some languages such as
79 * Hebrew the logically-leftmost text is not actually on the left when
80 * displayed.
81 *
82 * Marks are reference counted, but the reference count only controls the validity
83 * of the memory; marks can be deleted from the buffer at any time with
84 * gtk_text_buffer_delete_mark(). Once deleted from the buffer, a mark is
85 * essentially useless.
86 *
87 * Marks optionally have names; these can be convenient to avoid passing the
88 * #GtkTextMark object around.
89 *
90 * Marks are typically created using the gtk_text_buffer_create_mark() function.
91 */
92
93 /*
94 * Macro that determines the size of a mark segment:
95 */
96 #define MSEG_SIZE ((unsigned) (G_STRUCT_OFFSET (GtkTextLineSegment, body) \
97 + sizeof (GtkTextMarkBody)))
98
99 static void gtk_text_mark_set_property (GObject *object,
100 guint prop_id,
101 const GValue *value,
102 GParamSpec *pspec);
103 static void gtk_text_mark_get_property (GObject *object,
104 guint prop_id,
105 GValue *value,
106 GParamSpec *pspec);
107 static void gtk_text_mark_finalize (GObject *object);
108
109 static GtkTextLineSegment *gtk_mark_segment_new (GtkTextMark *mark_obj);
110
111 G_DEFINE_TYPE (GtkTextMark, gtk_text_mark, G_TYPE_OBJECT)
112
113 enum {
114 PROP_0,
115 PROP_NAME,
116 PROP_LEFT_GRAVITY
117 };
118
119 static void
gtk_text_mark_class_init(GtkTextMarkClass * klass)120 gtk_text_mark_class_init (GtkTextMarkClass *klass)
121 {
122 GObjectClass *object_class = G_OBJECT_CLASS (klass);
123
124 object_class->finalize = gtk_text_mark_finalize;
125 object_class->set_property = gtk_text_mark_set_property;
126 object_class->get_property = gtk_text_mark_get_property;
127
128 /**
129 * GtkTextMark:name:
130 *
131 * The name of the mark or %NULL if the mark is anonymous.
132 */
133 g_object_class_install_property (object_class,
134 PROP_NAME,
135 g_param_spec_string ("name",
136 P_("Name"),
137 P_("Mark name"),
138 NULL,
139 GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
140
141 /**
142 * GtkTextMark:left-gravity:
143 *
144 * Whether the mark has left gravity. When text is inserted at the mark’s
145 * current location, if the mark has left gravity it will be moved
146 * to the left of the newly-inserted text, otherwise to the right.
147 */
148 g_object_class_install_property (object_class,
149 PROP_LEFT_GRAVITY,
150 g_param_spec_boolean ("left-gravity",
151 P_("Left gravity"),
152 P_("Whether the mark has left gravity"),
153 FALSE,
154 GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
155 }
156
157 static void
gtk_text_mark_init(GtkTextMark * mark)158 gtk_text_mark_init (GtkTextMark *mark)
159 {
160 mark->segment = gtk_mark_segment_new (mark);
161 }
162
163 static void
gtk_text_mark_finalize(GObject * obj)164 gtk_text_mark_finalize (GObject *obj)
165 {
166 GtkTextMark *mark;
167 GtkTextLineSegment *seg;
168
169 mark = GTK_TEXT_MARK (obj);
170
171 seg = mark->segment;
172
173 if (seg)
174 {
175 if (seg->body.mark.tree != NULL)
176 g_warning ("GtkTextMark being finalized while still in the buffer; "
177 "someone removed a reference they didn't own! Crash "
178 "impending");
179
180 g_free (seg->body.mark.name);
181 g_slice_free1 (MSEG_SIZE, seg);
182
183 mark->segment = NULL;
184 }
185
186 /* chain parent_class' handler */
187 G_OBJECT_CLASS (gtk_text_mark_parent_class)->finalize (obj);
188 }
189
190 static void
gtk_text_mark_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)191 gtk_text_mark_set_property (GObject *object,
192 guint prop_id,
193 const GValue *value,
194 GParamSpec *pspec)
195 {
196 gchar *tmp;
197 GtkTextMark *mark = GTK_TEXT_MARK (object);
198 GtkTextLineSegment *seg = mark->segment;
199
200 switch (prop_id)
201 {
202 case PROP_NAME:
203 tmp = seg->body.mark.name;
204 seg->body.mark.name = g_value_dup_string (value);
205 g_free (tmp);
206 break;
207
208 case PROP_LEFT_GRAVITY:
209 if (g_value_get_boolean (value))
210 seg->type = >k_text_left_mark_type;
211 else
212 seg->type = >k_text_right_mark_type;
213 break;
214
215 default:
216 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
217 }
218 }
219
220 static void
gtk_text_mark_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)221 gtk_text_mark_get_property (GObject *object,
222 guint prop_id,
223 GValue *value,
224 GParamSpec *pspec)
225 {
226 GtkTextMark *mark = GTK_TEXT_MARK (object);
227
228 switch (prop_id)
229 {
230 case PROP_NAME:
231 g_value_set_string (value, gtk_text_mark_get_name (mark));
232 break;
233
234 case PROP_LEFT_GRAVITY:
235 g_value_set_boolean (value, gtk_text_mark_get_left_gravity (mark));
236 break;
237
238 default:
239 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
240 }
241 }
242
243 /**
244 * gtk_text_mark_new:
245 * @name: (allow-none): mark name or %NULL
246 * @left_gravity: whether the mark should have left gravity
247 *
248 * Creates a text mark. Add it to a buffer using gtk_text_buffer_add_mark().
249 * If @name is %NULL, the mark is anonymous; otherwise, the mark can be
250 * retrieved by name using gtk_text_buffer_get_mark(). If a mark has left
251 * gravity, and text is inserted at the mark’s current location, the mark
252 * will be moved to the left of the newly-inserted text. If the mark has
253 * right gravity (@left_gravity = %FALSE), the mark will end up on the
254 * right of newly-inserted text. The standard left-to-right cursor is a
255 * mark with right gravity (when you type, the cursor stays on the right
256 * side of the text you’re typing).
257 *
258 * Returns: new #GtkTextMark
259 *
260 * Since: 2.12
261 **/
262 GtkTextMark *
gtk_text_mark_new(const gchar * name,gboolean left_gravity)263 gtk_text_mark_new (const gchar *name,
264 gboolean left_gravity)
265 {
266 return g_object_new (GTK_TYPE_TEXT_MARK,
267 "name", name,
268 "left-gravity", left_gravity,
269 NULL);
270 }
271
272 /**
273 * gtk_text_mark_get_visible:
274 * @mark: a #GtkTextMark
275 *
276 * Returns %TRUE if the mark is visible (i.e. a cursor is displayed
277 * for it).
278 *
279 * Returns: %TRUE if visible
280 **/
281 gboolean
gtk_text_mark_get_visible(GtkTextMark * mark)282 gtk_text_mark_get_visible (GtkTextMark *mark)
283 {
284 GtkTextLineSegment *seg;
285
286 seg = mark->segment;
287
288 return seg->body.mark.visible;
289 }
290
291 /**
292 * gtk_text_mark_get_name:
293 * @mark: a #GtkTextMark
294 *
295 * Returns the mark name; returns NULL for anonymous marks.
296 *
297 * Returns: (nullable): mark name
298 **/
299 const char *
gtk_text_mark_get_name(GtkTextMark * mark)300 gtk_text_mark_get_name (GtkTextMark *mark)
301 {
302 GtkTextLineSegment *seg;
303
304 seg = mark->segment;
305
306 return seg->body.mark.name;
307 }
308
309 /**
310 * gtk_text_mark_get_deleted:
311 * @mark: a #GtkTextMark
312 *
313 * Returns %TRUE if the mark has been removed from its buffer
314 * with gtk_text_buffer_delete_mark(). See gtk_text_buffer_add_mark()
315 * for a way to add it to a buffer again.
316 *
317 * Returns: whether the mark is deleted
318 **/
319 gboolean
gtk_text_mark_get_deleted(GtkTextMark * mark)320 gtk_text_mark_get_deleted (GtkTextMark *mark)
321 {
322 GtkTextLineSegment *seg;
323
324 g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), FALSE);
325
326 seg = mark->segment;
327
328 if (seg == NULL)
329 return TRUE;
330
331 return seg->body.mark.tree == NULL;
332 }
333
334 /**
335 * gtk_text_mark_get_buffer:
336 * @mark: a #GtkTextMark
337 *
338 * Gets the buffer this mark is located inside,
339 * or %NULL if the mark is deleted.
340 *
341 * Returns: (transfer none): the mark’s #GtkTextBuffer
342 **/
343 GtkTextBuffer*
gtk_text_mark_get_buffer(GtkTextMark * mark)344 gtk_text_mark_get_buffer (GtkTextMark *mark)
345 {
346 GtkTextLineSegment *seg;
347
348 g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), NULL);
349
350 seg = mark->segment;
351
352 if (seg->body.mark.tree == NULL)
353 return NULL;
354 else
355 return _gtk_text_btree_get_buffer (seg->body.mark.tree);
356 }
357
358 /**
359 * gtk_text_mark_get_left_gravity:
360 * @mark: a #GtkTextMark
361 *
362 * Determines whether the mark has left gravity.
363 *
364 * Returns: %TRUE if the mark has left gravity, %FALSE otherwise
365 **/
366 gboolean
gtk_text_mark_get_left_gravity(GtkTextMark * mark)367 gtk_text_mark_get_left_gravity (GtkTextMark *mark)
368 {
369 GtkTextLineSegment *seg;
370
371 g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), FALSE);
372
373 seg = mark->segment;
374
375 return seg->type == >k_text_left_mark_type;
376 }
377
378 static GtkTextLineSegment *
gtk_mark_segment_new(GtkTextMark * mark_obj)379 gtk_mark_segment_new (GtkTextMark *mark_obj)
380 {
381 GtkTextLineSegment *mark;
382
383 mark = g_slice_alloc0 (MSEG_SIZE);
384 mark->body.mark.name = NULL;
385 mark->type = >k_text_right_mark_type;
386
387 mark->byte_count = 0;
388 mark->char_count = 0;
389
390 mark->body.mark.obj = mark_obj;
391 mark_obj->segment = mark;
392
393 mark->body.mark.tree = NULL;
394 mark->body.mark.line = NULL;
395 mark->next = NULL;
396
397 mark->body.mark.visible = FALSE;
398 mark->body.mark.not_deleteable = FALSE;
399
400 return mark;
401 }
402
403 void
_gtk_mark_segment_set_tree(GtkTextLineSegment * mark,GtkTextBTree * tree)404 _gtk_mark_segment_set_tree (GtkTextLineSegment *mark,
405 GtkTextBTree *tree)
406 {
407 g_assert (mark->body.mark.tree == NULL);
408 g_assert (mark->body.mark.obj != NULL);
409
410 mark->byte_count = 0;
411 mark->char_count = 0;
412
413 mark->body.mark.tree = tree;
414 mark->body.mark.line = NULL;
415 mark->next = NULL;
416
417 mark->body.mark.not_deleteable = FALSE;
418 }
419
420 static int mark_segment_delete_func (GtkTextLineSegment *segPtr,
421 GtkTextLine *line,
422 int treeGone);
423 static GtkTextLineSegment *mark_segment_cleanup_func (GtkTextLineSegment *segPtr,
424 GtkTextLine *line);
425 static void mark_segment_check_func (GtkTextLineSegment *segPtr,
426 GtkTextLine *line);
427
428
429 /*
430 * The following structures declare the "mark" segment types.
431 * There are actually two types for marks, one with left gravity
432 * and one with right gravity. They are identical except for
433 * their gravity property.
434 */
435
436 const GtkTextLineSegmentClass gtk_text_right_mark_type = {
437 "mark", /* name */
438 FALSE, /* leftGravity */
439 NULL, /* splitFunc */
440 mark_segment_delete_func, /* deleteFunc */
441 mark_segment_cleanup_func, /* cleanupFunc */
442 NULL, /* lineChangeFunc */
443 mark_segment_check_func /* checkFunc */
444 };
445
446 const GtkTextLineSegmentClass gtk_text_left_mark_type = {
447 "mark", /* name */
448 TRUE, /* leftGravity */
449 NULL, /* splitFunc */
450 mark_segment_delete_func, /* deleteFunc */
451 mark_segment_cleanup_func, /* cleanupFunc */
452 NULL, /* lineChangeFunc */
453 mark_segment_check_func /* checkFunc */
454 };
455
456 /*
457 *--------------------------------------------------------------
458 *
459 * mark_segment_delete_func --
460 *
461 * This procedure is invoked by the text B-tree code whenever
462 * a mark lies in a range of characters being deleted.
463 *
464 * Results:
465 * Returns 1 to indicate that deletion has been rejected,
466 * or 0 otherwise
467 *
468 * Side effects:
469 * Frees mark if tree is going away
470 *
471 *--------------------------------------------------------------
472 */
473
474 static gboolean
mark_segment_delete_func(GtkTextLineSegment * seg,GtkTextLine * line,gboolean tree_gone)475 mark_segment_delete_func (GtkTextLineSegment *seg,
476 GtkTextLine *line,
477 gboolean tree_gone)
478 {
479 if (tree_gone)
480 {
481 _gtk_text_btree_release_mark_segment (seg->body.mark.tree, seg);
482 return FALSE;
483 }
484 else
485 return TRUE;
486 }
487
488 /*
489 *--------------------------------------------------------------
490 *
491 * mark_segment_cleanup_func --
492 *
493 * This procedure is invoked by the B-tree code whenever a
494 * mark segment is moved from one line to another.
495 *
496 * Results:
497 * None.
498 *
499 * Side effects:
500 * The line field of the segment gets updated.
501 *
502 *--------------------------------------------------------------
503 */
504
505 static GtkTextLineSegment *
mark_segment_cleanup_func(GtkTextLineSegment * seg,GtkTextLine * line)506 mark_segment_cleanup_func (GtkTextLineSegment *seg,
507 GtkTextLine *line)
508 {
509 /* not sure why Tk did this here and not in LineChangeFunc */
510 seg->body.mark.line = line;
511 return seg;
512 }
513
514 /*
515 *--------------------------------------------------------------
516 *
517 * mark_segment_check_func --
518 *
519 * This procedure is invoked by the B-tree code to perform
520 * consistency checks on mark segments.
521 *
522 * Results:
523 * None.
524 *
525 * Side effects:
526 * The procedure panics if it detects anything wrong with
527 * the mark.
528 *
529 *--------------------------------------------------------------
530 */
531
532 static void
mark_segment_check_func(GtkTextLineSegment * seg,GtkTextLine * line)533 mark_segment_check_func (GtkTextLineSegment *seg,
534 GtkTextLine *line)
535 {
536 if (seg->body.mark.line != line)
537 g_error ("mark_segment_check_func: seg->body.mark.line bogus");
538 }
539