gtk/gtk/gtktextmark.c
2023-03-14 14:56:42 -04:00

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/* gtktextmark.c - mark segments
*
* Copyright (c) 1994 The Regents of the University of California.
* Copyright (c) 1994-1997 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 "gtktextbtreeprivate.h"
#include "gtkprivate.h"
/**
* GtkTextMark:
*
* A `GtkTextMark` is a position in a `GtkTextbuffer` that is preserved
* across modifications.
*
* You may wish to begin by reading the
* [text widget conceptual overview](section-text-widget.html),
* which gives an overview of all the objects and data types
* related to the text widget and how they work together.
*
* A `GtkTextMark` is like a bookmark in a text buffer; it preserves
* a position in the text. You can convert the mark to an iterator using
* [method@Gtk.TextBuffer.get_iter_at_mark]. Unlike iterators, marks remain
* valid across buffer mutations, because their behavior is defined when
* text is inserted or deleted. When text containing a mark is deleted,
* the mark remains in the position originally occupied by the deleted
* text. When text is inserted at a mark, a mark with “left gravity” will
* be moved to the beginning of the newly-inserted text, and a mark with
* “right gravity” will be moved to the end.
*
* Note that “left” and “right” here refer to logical direction (left
* is the toward the start of the buffer); in some languages such as
* Hebrew the logically-leftmost text is not actually on the left when
* displayed.
*
* Marks are reference counted, but the reference count only controls
* the validity of the memory; marks can be deleted from the buffer at
* any time with [method@Gtk.TextBuffer.delete_mark]. Once deleted from
* the buffer, a mark is essentially useless.
*
* Marks optionally have names; these can be convenient to avoid passing
* the `GtkTextMark` object around.
*
* Marks are typically created using the [method@Gtk.TextBuffer.create_mark]
* function.
*/
/*
* Macro that determines the size of a mark segment:
*/
#define MSEG_SIZE ((unsigned) (G_STRUCT_OFFSET (GtkTextLineSegment, body) \
+ sizeof (GtkTextMarkBody)))
static void gtk_text_mark_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec);
static void gtk_text_mark_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
static void gtk_text_mark_finalize (GObject *object);
static GtkTextLineSegment *gtk_mark_segment_new (GtkTextMark *mark_obj);
G_DEFINE_TYPE (GtkTextMark, gtk_text_mark, G_TYPE_OBJECT)
enum {
PROP_0,
PROP_NAME,
PROP_LEFT_GRAVITY
};
static void
gtk_text_mark_class_init (GtkTextMarkClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = gtk_text_mark_finalize;
object_class->set_property = gtk_text_mark_set_property;
object_class->get_property = gtk_text_mark_get_property;
/**
* GtkTextMark:name:
*
* The name of the mark or %NULL if the mark is anonymous.
*/
g_object_class_install_property (object_class,
PROP_NAME,
g_param_spec_string ("name", NULL, NULL,
NULL,
GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
/**
* GtkTextMark:left-gravity:
*
* Whether the mark has left gravity.
*
* When text is inserted at the marks current location, if the mark
* has left gravity it will be moved to the left of the newly-inserted
* text, otherwise to the right.
*/
g_object_class_install_property (object_class,
PROP_LEFT_GRAVITY,
g_param_spec_boolean ("left-gravity", NULL, NULL,
FALSE,
GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
}
static void
gtk_text_mark_init (GtkTextMark *mark)
{
mark->segment = gtk_mark_segment_new (mark);
}
static void
gtk_text_mark_finalize (GObject *obj)
{
GtkTextMark *mark;
GtkTextLineSegment *seg;
mark = GTK_TEXT_MARK (obj);
seg = mark->segment;
if (seg)
{
if (seg->body.mark.tree != NULL)
g_warning ("GtkTextMark being finalized while still in the buffer; "
"someone removed a reference they didn't own! Crash "
"impending");
g_free (seg->body.mark.name);
g_free (seg);
mark->segment = NULL;
}
/* chain parent_class' handler */
G_OBJECT_CLASS (gtk_text_mark_parent_class)->finalize (obj);
}
static void
gtk_text_mark_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
char *tmp;
GtkTextMark *mark = GTK_TEXT_MARK (object);
GtkTextLineSegment *seg = mark->segment;
switch (prop_id)
{
case PROP_NAME:
tmp = seg->body.mark.name;
seg->body.mark.name = g_value_dup_string (value);
g_free (tmp);
break;
case PROP_LEFT_GRAVITY:
if (g_value_get_boolean (value))
seg->type = &gtk_text_left_mark_type;
else
seg->type = &gtk_text_right_mark_type;
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
static void
gtk_text_mark_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkTextMark *mark = GTK_TEXT_MARK (object);
switch (prop_id)
{
case PROP_NAME:
g_value_set_string (value, gtk_text_mark_get_name (mark));
break;
case PROP_LEFT_GRAVITY:
g_value_set_boolean (value, gtk_text_mark_get_left_gravity (mark));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
/**
* gtk_text_mark_new:
* @name: (nullable): mark name
* @left_gravity: whether the mark should have left gravity
*
* Creates a text mark.
*
* Add it to a buffer using [method@Gtk.TextBuffer.add_mark].
* If @name is %NULL, the mark is anonymous; otherwise, the mark can be
* retrieved by name using [method@Gtk.TextBuffer.get_mark]. If a mark
* has left gravity, and text is inserted at the marks current location,
* the mark will be moved to the left of the newly-inserted text. If the
* mark has right gravity (@left_gravity = %FALSE), the mark will end up
* on the right of newly-inserted text. The standard left-to-right cursor
* is a mark with right gravity (when you type, the cursor stays on the
* right side of the text youre typing).
*
* Returns: new `GtkTextMark`
*/
GtkTextMark *
gtk_text_mark_new (const char *name,
gboolean left_gravity)
{
return g_object_new (GTK_TYPE_TEXT_MARK,
"name", name,
"left-gravity", left_gravity,
NULL);
}
/**
* gtk_text_mark_get_visible:
* @mark: a `GtkTextMark`
*
* Returns %TRUE if the mark is visible.
*
* A cursor is displayed for visible marks.
*
* Returns: %TRUE if visible
*/
gboolean
gtk_text_mark_get_visible (GtkTextMark *mark)
{
GtkTextLineSegment *seg;
seg = mark->segment;
return seg->body.mark.visible;
}
/**
* gtk_text_mark_get_name:
* @mark: a `GtkTextMark`
*
* Returns the mark name.
*
* Returns %NULL for anonymous marks.
*
* Returns: (nullable): mark name
*/
const char *
gtk_text_mark_get_name (GtkTextMark *mark)
{
GtkTextLineSegment *seg;
seg = mark->segment;
return seg->body.mark.name;
}
/**
* gtk_text_mark_get_deleted:
* @mark: a `GtkTextMark`
*
* Returns %TRUE if the mark has been removed from its buffer.
*
* See [method@Gtk.TextBuffer.add_mark] for a way to add it
* to a buffer again.
*
* Returns: whether the mark is deleted
*/
gboolean
gtk_text_mark_get_deleted (GtkTextMark *mark)
{
GtkTextLineSegment *seg;
g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), FALSE);
seg = mark->segment;
if (seg == NULL)
return TRUE;
return seg->body.mark.tree == NULL;
}
/**
* gtk_text_mark_get_buffer:
* @mark: a `GtkTextMark`
*
* Gets the buffer this mark is located inside.
*
* Returns %NULL if the mark is deleted.
*
* Returns: (transfer none) (nullable): the marks `GtkTextBuffer`
*/
GtkTextBuffer*
gtk_text_mark_get_buffer (GtkTextMark *mark)
{
GtkTextLineSegment *seg;
g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), NULL);
seg = mark->segment;
if (seg->body.mark.tree == NULL)
return NULL;
else
return _gtk_text_btree_get_buffer (seg->body.mark.tree);
}
/**
* gtk_text_mark_get_left_gravity:
* @mark: a `GtkTextMark`
*
* Determines whether the mark has left gravity.
*
* Returns: %TRUE if the mark has left gravity, %FALSE otherwise
*/
gboolean
gtk_text_mark_get_left_gravity (GtkTextMark *mark)
{
GtkTextLineSegment *seg;
g_return_val_if_fail (GTK_IS_TEXT_MARK (mark), FALSE);
seg = mark->segment;
return seg->type == &gtk_text_left_mark_type;
}
static GtkTextLineSegment *
gtk_mark_segment_new (GtkTextMark *mark_obj)
{
GtkTextLineSegment *mark;
mark = g_malloc0 (MSEG_SIZE);
mark->body.mark.name = NULL;
mark->type = &gtk_text_right_mark_type;
mark->byte_count = 0;
mark->char_count = 0;
mark->body.mark.obj = mark_obj;
mark_obj->segment = mark;
mark->body.mark.tree = NULL;
mark->body.mark.line = NULL;
mark->next = NULL;
mark->body.mark.visible = FALSE;
mark->body.mark.not_deleteable = FALSE;
return mark;
}
void
_gtk_mark_segment_set_tree (GtkTextLineSegment *mark,
GtkTextBTree *tree)
{
g_assert (mark->body.mark.tree == NULL);
g_assert (mark->body.mark.obj != NULL);
mark->byte_count = 0;
mark->char_count = 0;
mark->body.mark.tree = tree;
mark->body.mark.line = NULL;
mark->next = NULL;
mark->body.mark.not_deleteable = FALSE;
}
static int mark_segment_delete_func (GtkTextLineSegment *segPtr,
GtkTextLine *line,
int treeGone);
static GtkTextLineSegment *mark_segment_cleanup_func (GtkTextLineSegment *segPtr,
GtkTextLine *line);
static void mark_segment_check_func (GtkTextLineSegment *segPtr,
GtkTextLine *line);
/*
* The following structures declare the "mark" segment types.
* There are actually two types for marks, one with left gravity
* and one with right gravity. They are identical except for
* their gravity property.
*/
const GtkTextLineSegmentClass gtk_text_right_mark_type = {
"mark", /* name */
FALSE, /* leftGravity */
NULL, /* splitFunc */
mark_segment_delete_func, /* deleteFunc */
mark_segment_cleanup_func, /* cleanupFunc */
NULL, /* lineChangeFunc */
mark_segment_check_func /* checkFunc */
};
const GtkTextLineSegmentClass gtk_text_left_mark_type = {
"mark", /* name */
TRUE, /* leftGravity */
NULL, /* splitFunc */
mark_segment_delete_func, /* deleteFunc */
mark_segment_cleanup_func, /* cleanupFunc */
NULL, /* lineChangeFunc */
mark_segment_check_func /* checkFunc */
};
/*
*--------------------------------------------------------------
*
* mark_segment_delete_func --
*
* This procedure is invoked by the text B-tree code whenever
* a mark lies in a range of characters being deleted.
*
* Results:
* Returns 1 to indicate that deletion has been rejected,
* or 0 otherwise
*
* Side effects:
* Frees mark if tree is going away
*
*--------------------------------------------------------------
*/
static gboolean
mark_segment_delete_func (GtkTextLineSegment *seg,
GtkTextLine *line,
gboolean tree_gone)
{
if (tree_gone)
{
_gtk_text_btree_release_mark_segment (seg->body.mark.tree, seg);
return FALSE;
}
else
return TRUE;
}
/*
*--------------------------------------------------------------
*
* mark_segment_cleanup_func --
*
* This procedure is invoked by the B-tree code whenever a
* mark segment is moved from one line to another.
*
* Results:
* None.
*
* Side effects:
* The line field of the segment gets updated.
*
*--------------------------------------------------------------
*/
static GtkTextLineSegment *
mark_segment_cleanup_func (GtkTextLineSegment *seg,
GtkTextLine *line)
{
/* not sure why Tk did this here and not in LineChangeFunc */
seg->body.mark.line = line;
return seg;
}
/*
*--------------------------------------------------------------
*
* mark_segment_check_func --
*
* This procedure is invoked by the B-tree code to perform
* consistency checks on mark segments.
*
* Results:
* None.
*
* Side effects:
* The procedure panics if it detects anything wrong with
* the mark.
*
*--------------------------------------------------------------
*/
static void
mark_segment_check_func (GtkTextLineSegment *seg,
GtkTextLine *line)
{
if (seg->body.mark.line != line)
g_error ("mark_segment_check_func: seg->body.mark.line bogus");
}