1 /* gtktextmark.c - mark segments
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>
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.
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50 #define GTK_TEXT_USE_INTERNAL_UNSUPPORTED_API
52 #include "gtktextbtree.h"
53 #include "gtkprivate.h"
59 * @Short_description: A position in the buffer preserved across buffer modifications
62 * You may wish to begin by reading the <link linkend="TextWidget">text widget
63 * conceptual overview</link> which gives an overview of all the objects and data
64 * types related to the text widget and how they work together.
66 * A #GtkTextMark is like a bookmark in a text buffer; it preserves a position in
67 * the text. You can convert the mark to an iterator using
68 * gtk_text_buffer_get_iter_at_mark(). Unlike iterators, marks remain valid across
69 * buffer mutations, because their behavior is defined when text is inserted or
70 * deleted. When text containing a mark is deleted, the mark remains in the
71 * position originally occupied by the deleted text. When text is inserted at a
72 * mark, a mark with <firstterm>left gravity</firstterm> will be moved to the
73 * beginning of the newly-inserted text, and a mark with <firstterm>right
74 * gravity</firstterm> will be moved to the end.
77 * "left" and "right" here refer to logical direction (left is the toward the start
78 * of the buffer); in some languages such as Hebrew the logically-leftmost text is
79 * not actually on the left when displayed.
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.
87 * Marks optionally have names; these can be convenient to avoid passing the
88 * #GtkTextMark object around.
90 * Marks are typically created using the gtk_text_buffer_create_mark() function.
94 static void gtk_text_mark_set_property (GObject *object,
98 static void gtk_text_mark_get_property (GObject *object,
102 static void gtk_text_mark_finalize (GObject *object);
104 static GtkTextLineSegment *gtk_mark_segment_new (GtkTextMark *mark_obj);
106 G_DEFINE_TYPE (GtkTextMark, gtk_text_mark, G_TYPE_OBJECT)
115 gtk_text_mark_class_init (GtkTextMarkClass *klass)
117 GObjectClass *object_class = G_OBJECT_CLASS (klass);
119 object_class->finalize = gtk_text_mark_finalize;
120 object_class->set_property = gtk_text_mark_set_property;
121 object_class->get_property = gtk_text_mark_get_property;
123 g_object_class_install_property (object_class,
125 g_param_spec_string ("name",
129 GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
131 g_object_class_install_property (object_class,
133 g_param_spec_boolean ("left-gravity",
135 P_("Whether the mark has left gravity"),
137 GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
141 gtk_text_mark_init (GtkTextMark *mark)
143 mark->segment = gtk_mark_segment_new (mark);
147 gtk_text_mark_finalize (GObject *obj)
150 GtkTextLineSegment *seg;
152 mark = GTK_TEXT_MARK (obj);
158 if (seg->body.mark.tree != NULL)
159 g_warning ("GtkTextMark being finalized while still in the buffer; "
160 "someone removed a reference they didn't own! Crash "
163 g_free (seg->body.mark.name);
166 mark->segment = NULL;
169 /* chain parent_class' handler */
170 G_OBJECT_CLASS (gtk_text_mark_parent_class)->finalize (obj);
174 gtk_text_mark_set_property (GObject *object,
180 GtkTextMark *mark = GTK_TEXT_MARK (object);
181 GtkTextLineSegment *seg = mark->segment;
186 tmp = seg->body.mark.name;
187 seg->body.mark.name = g_value_dup_string (value);
191 case PROP_LEFT_GRAVITY:
192 if (g_value_get_boolean (value))
193 seg->type = >k_text_left_mark_type;
195 seg->type = >k_text_right_mark_type;
199 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
204 gtk_text_mark_get_property (GObject *object,
209 GtkTextMark *mark = GTK_TEXT_MARK (object);
214 g_value_set_string (value, gtk_text_mark_get_name (mark));
217 case PROP_LEFT_GRAVITY:
218 g_value_set_boolean (value, gtk_text_mark_get_left_gravity (mark));
222 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
228 * @name: (allow-none): mark name or %NULL
229 * @left_gravity: whether the mark should have left gravity
231 * Creates a text mark. Add it to a buffer using gtk_text_buffer_add_mark().
232 * If @name is %NULL, the mark is anonymous; otherwise, the mark can be
233 * retrieved by name using gtk_text_buffer_get_mark(). If a mark has left
234 * gravity, and text is inserted at the mark's current location, the mark
235 * will be moved to the left of the newly-inserted text. If the mark has
236 * right gravity (@left_gravity = %FALSE), the mark will end up on the
237 * right of newly-inserted text. The standard left-to-right cursor is a
238 * mark with right gravity (when you type, the cursor stays on the right
239 * side of the text you're typing).
241 * Return value: new #GtkTextMark
246 gtk_text_mark_new (const gchar *name,
247 gboolean left_gravity)
249 return g_object_new (GTK_TYPE_TEXT_MARK,
251 "left-gravity", left_gravity,
256 * gtk_text_mark_get_visible:
257 * @mark: a #GtkTextMark
259 * Returns %TRUE if the mark is visible (i.e. a cursor is displayed
262 * Return value: %TRUE if visible
265 gtk_text_mark_get_visible (GtkTextMark *mark)
267 GtkTextLineSegment *seg;
271 return seg->body.mark.visible;
275 * gtk_text_mark_get_name:
276 * @mark: a #GtkTextMark
278 * Returns the mark name; returns NULL for anonymous marks.
280 * Return value: mark name
283 gtk_text_mark_get_name (GtkTextMark *mark)
285 GtkTextLineSegment *seg;
289 return seg->body.mark.name;
293 * gtk_text_mark_get_deleted:
294 * @mark: a #GtkTextMark
296 * Returns %TRUE if the mark has been removed from its buffer
297 * with gtk_text_buffer_delete_mark(). See gtk_text_buffer_add_mark()
298 * for a way to add it to a buffer again.
300 * Return value: whether the mark is deleted
303 gtk_text_mark_get_deleted (GtkTextMark *mark)
305 GtkTextLineSegment *seg;
307 g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), FALSE);
314 return seg->body.mark.tree == NULL;
318 * gtk_text_mark_get_buffer:
319 * @mark: a #GtkTextMark
321 * Gets the buffer this mark is located inside,
322 * or %NULL if the mark is deleted.
324 * Return value: (transfer none): the mark's #GtkTextBuffer
327 gtk_text_mark_get_buffer (GtkTextMark *mark)
329 GtkTextLineSegment *seg;
331 g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), NULL);
335 if (seg->body.mark.tree == NULL)
338 return _gtk_text_btree_get_buffer (seg->body.mark.tree);
342 * gtk_text_mark_get_left_gravity:
343 * @mark: a #GtkTextMark
345 * Determines whether the mark has left gravity.
347 * Return value: %TRUE if the mark has left gravity, %FALSE otherwise
350 gtk_text_mark_get_left_gravity (GtkTextMark *mark)
352 GtkTextLineSegment *seg;
354 g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), FALSE);
358 return seg->type == >k_text_left_mark_type;
362 * Macro that determines the size of a mark segment:
365 #define MSEG_SIZE ((unsigned) (G_STRUCT_OFFSET (GtkTextLineSegment, body) \
366 + sizeof (GtkTextMarkBody)))
369 static GtkTextLineSegment *
370 gtk_mark_segment_new (GtkTextMark *mark_obj)
372 GtkTextLineSegment *mark;
374 mark = (GtkTextLineSegment *) g_malloc0 (MSEG_SIZE);
375 mark->body.mark.name = NULL;
376 mark->type = >k_text_right_mark_type;
378 mark->byte_count = 0;
379 mark->char_count = 0;
381 mark->body.mark.obj = mark_obj;
382 mark_obj->segment = mark;
384 mark->body.mark.tree = NULL;
385 mark->body.mark.line = NULL;
388 mark->body.mark.visible = FALSE;
389 mark->body.mark.not_deleteable = FALSE;
395 _gtk_mark_segment_set_tree (GtkTextLineSegment *mark,
398 g_assert (mark->body.mark.tree == NULL);
399 g_assert (mark->body.mark.obj != NULL);
401 mark->byte_count = 0;
402 mark->char_count = 0;
404 mark->body.mark.tree = tree;
405 mark->body.mark.line = NULL;
408 mark->body.mark.not_deleteable = FALSE;
411 static int mark_segment_delete_func (GtkTextLineSegment *segPtr,
414 static GtkTextLineSegment *mark_segment_cleanup_func (GtkTextLineSegment *segPtr,
416 static void mark_segment_check_func (GtkTextLineSegment *segPtr,
421 * The following structures declare the "mark" segment types.
422 * There are actually two types for marks, one with left gravity
423 * and one with right gravity. They are identical except for
424 * their gravity property.
427 const GtkTextLineSegmentClass gtk_text_right_mark_type = {
429 FALSE, /* leftGravity */
430 NULL, /* splitFunc */
431 mark_segment_delete_func, /* deleteFunc */
432 mark_segment_cleanup_func, /* cleanupFunc */
433 NULL, /* lineChangeFunc */
434 mark_segment_check_func /* checkFunc */
437 const GtkTextLineSegmentClass gtk_text_left_mark_type = {
439 TRUE, /* leftGravity */
440 NULL, /* splitFunc */
441 mark_segment_delete_func, /* deleteFunc */
442 mark_segment_cleanup_func, /* cleanupFunc */
443 NULL, /* lineChangeFunc */
444 mark_segment_check_func /* checkFunc */
448 *--------------------------------------------------------------
450 * mark_segment_delete_func --
452 * This procedure is invoked by the text B-tree code whenever
453 * a mark lies in a range of characters being deleted.
456 * Returns 1 to indicate that deletion has been rejected,
460 * Frees mark if tree is going away
462 *--------------------------------------------------------------
466 mark_segment_delete_func (GtkTextLineSegment *seg,
472 _gtk_text_btree_release_mark_segment (seg->body.mark.tree, seg);
480 *--------------------------------------------------------------
482 * mark_segment_cleanup_func --
484 * This procedure is invoked by the B-tree code whenever a
485 * mark segment is moved from one line to another.
491 * The line field of the segment gets updated.
493 *--------------------------------------------------------------
496 static GtkTextLineSegment *
497 mark_segment_cleanup_func (GtkTextLineSegment *seg,
500 /* not sure why Tk did this here and not in LineChangeFunc */
501 seg->body.mark.line = line;
506 *--------------------------------------------------------------
508 * mark_segment_check_func --
510 * This procedure is invoked by the B-tree code to perform
511 * consistency checks on mark segments.
517 * The procedure panics if it detects anything wrong with
520 *--------------------------------------------------------------
524 mark_segment_check_func (GtkTextLineSegment *seg,
527 if (seg->body.mark.line != line)
528 g_error ("mark_segment_check_func: seg->body.mark.line bogus");