/* Record that a deletion is about to take place, of the characters in
STRING, at location BEG. Optionally record adjustments for markers
in the region STRING occupies in the current buffer. */
void
record_delete (ptrdiff_t beg, Lisp_Object string, bool record_markers)
{
Lisp_Object sbeg;
if (EQ (BVAR (current_buffer, undo_list), Qt))
return;
if (point_before_last_command_or_undo != beg
&& buffer_before_last_command_or_undo == current_buffer)
record_point (point_before_last_command_or_undo);
if (PT == beg + SCHARS (string))
{
XSETINT (sbeg, -beg);
prepare_record ();
}
else
{
XSETFASTINT (sbeg, beg);
prepare_record ();
}
/* primitive-undo assumes marker adjustments are recorded
immediately before the deletion is recorded. See bug 16818
discussion. */
if (record_markers)
record_marker_adjustments (beg, beg + SCHARS (string));
bset_undo_list
(current_buffer,
Fcons (Fcons (string, sbeg), BVAR (current_buffer, undo_list)));
}
void
record_insert (ptrdiff_t beg, ptrdiff_t length)
{
Lisp_Object lbeg, lend;
if (EQ (BVAR (current_buffer, undo_list), Qt))
return;
prepare_record ();
record_point (beg);
/* If this is following another insertion and consecutive with it
in the buffer, combine the two. */
if (CONSP (BVAR (current_buffer, undo_list)))
{
Lisp_Object elt;
elt = XCAR (BVAR (current_buffer, undo_list));
if (CONSP (elt)
&& INTEGERP (XCAR (elt))
&& INTEGERP (XCDR (elt))
&& XINT (XCDR (elt)) == beg)
{
XSETCDR (elt, make_number (beg + length));
return;
}
}
XSETFASTINT (lbeg, beg);
XSETINT (lend, beg + length);
bset_undo_list (current_buffer,
Fcons (Fcons (lbeg, lend), BVAR (current_buffer, undo_list)));
}
/* Record point as it was at beginning of this command.
PT is the position of point that will naturally occur as a result of the
undo record that will be added just after this command terminates. */
static void
record_point (ptrdiff_t pt)
{
/* Don't record position of pt when undo_inhibit_record_point holds. */
if (undo_inhibit_record_point)
return;
bool at_boundary;
at_boundary = ! CONSP (BVAR (current_buffer, undo_list))
|| NILP (XCAR (BVAR (current_buffer, undo_list)));
prepare_record ();
/* If we are just after an undo boundary, and
point wasn't at start of deleted range, record where it was. */
if (at_boundary)
bset_undo_list (current_buffer,
Fcons (make_number (pt),
BVAR (current_buffer, undo_list)));
}
void
record_property_change (ptrdiff_t beg, ptrdiff_t length,
Lisp_Object prop, Lisp_Object value,
Lisp_Object buffer)
{
Lisp_Object lbeg, lend, entry;
struct buffer *buf = XBUFFER (buffer);
if (EQ (BVAR (buf, undo_list), Qt))
return;
prepare_record();
if (MODIFF <= SAVE_MODIFF)
record_first_change ();
XSETINT (lbeg, beg);
XSETINT (lend, beg + length);
entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend))));
bset_undo_list (current_buffer,
Fcons (entry, BVAR (current_buffer, undo_list)));
}
static void
record_marker_adjustments (ptrdiff_t from, ptrdiff_t to)
{
Lisp_Object marker;
register struct Lisp_Marker *m;
register ptrdiff_t charpos, adjustment;
prepare_record();
for (m = BUF_MARKERS (current_buffer); m; m = m->next)
{
charpos = m->charpos;
eassert (charpos <= Z);
if (from <= charpos && charpos <= to)
{
/* insertion_type nil markers will end up at the beginning of
the re-inserted text after undoing a deletion, and must be
adjusted to move them to the correct place.
insertion_type t markers will automatically move forward
upon re-inserting the deleted text, so we have to arrange
for them to move backward to the correct position. */
adjustment = (m->insertion_type ? to : from) - charpos;
if (adjustment)
{
XSETMISC (marker, m);
bset_undo_list
(current_buffer,
Fcons (Fcons (marker, make_number (adjustment)),
BVAR (current_buffer, undo_list)));
}
}
}
}
