/* undo handling for GNU Emacs.
- Copyright (C) 1990, 1993 Free Software Foundation, Inc.
+ Copyright (C) 1990, 1993, 1994, 2000 Free Software Foundation, Inc.
This file is part of GNU Emacs.
+GNU Emacs is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
GNU Emacs is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY. No author or distributor
-accepts responsibility to anyone for the consequences of using it
-or for whether it serves any particular purpose or works at all,
-unless he says so in writing. Refer to the GNU Emacs General Public
-License for full details.
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
-Everyone is granted permission to copy, modify and redistribute
-GNU Emacs, but only under the conditions described in the
-GNU Emacs General Public License. A copy of this license is
-supposed to have been given to you along with GNU Emacs so you
-can know your rights and responsibilities. It should be in a
-file named COPYING. Among other things, the copyright notice
-and this notice must be preserved on all copies. */
+You should have received a copy of the GNU General Public License
+along with GNU Emacs; see the file COPYING. If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA. */
#include <config.h>
#include "lisp.h"
#include "buffer.h"
+#include "commands.h"
/* Last buffer for which undo information was recorded. */
Lisp_Object last_undo_buffer;
Lisp_Object Qinhibit_read_only;
+/* The first time a command records something for undo.
+ it also allocates the undo-boundary object
+ which will be added to the list at the end of the command.
+ This ensures we can't run out of space while trying to make
+ an undo-boundary. */
+Lisp_Object pending_boundary;
+
+/* Record point as it was at beginning of this command (if necessary)
+ And prepare the undo info for recording a change.
+ 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 (pt)
+ int pt;
+{
+ int at_boundary;
+
+ /* Allocate a cons cell to be the undo boundary after this command. */
+ if (NILP (pending_boundary))
+ pending_boundary = Fcons (Qnil, Qnil);
+
+ if (!BUFFERP (last_undo_buffer)
+ || current_buffer != XBUFFER (last_undo_buffer))
+ Fundo_boundary ();
+ XSETBUFFER (last_undo_buffer, current_buffer);
+
+ if (CONSP (current_buffer->undo_list))
+ {
+ /* Set AT_BOUNDARY to 1 only when we have nothing other than
+ marker adjustment before undo boundary. */
+
+ Lisp_Object tail = current_buffer->undo_list, elt;
+
+ while (1)
+ {
+ if (NILP (tail))
+ elt = Qnil;
+ else
+ elt = XCAR (tail);
+ if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt))))
+ break;
+ tail = XCDR (tail);
+ }
+ at_boundary = NILP (elt);
+ }
+ else
+ at_boundary = 1;
+
+ if (MODIFF <= SAVE_MODIFF)
+ record_first_change ();
+
+ /* If we are just after an undo boundary, and
+ point wasn't at start of deleted range, record where it was. */
+ if (at_boundary
+ && last_point_position != pt
+ /* If we're called from batch mode, this could be nil. */
+ && BUFFERP (last_point_position_buffer)
+ && current_buffer == XBUFFER (last_point_position_buffer))
+ current_buffer->undo_list
+ = Fcons (make_number (last_point_position), current_buffer->undo_list);
+}
+
/* Record an insertion that just happened or is about to happen,
for LENGTH characters at position BEG.
(It is possible to record an insertion before or after the fact
because we don't need to record the contents.) */
+void
record_insert (beg, length)
- Lisp_Object beg, length;
+ int beg, length;
{
Lisp_Object lbeg, lend;
if (EQ (current_buffer->undo_list, Qt))
return;
- if (current_buffer != XBUFFER (last_undo_buffer))
- Fundo_boundary ();
- XSET (last_undo_buffer, Lisp_Buffer, current_buffer);
-
- if (MODIFF <= current_buffer->save_modified)
- record_first_change ();
+ record_point (beg);
/* If this is following another insertion and consecutive with it
in the buffer, combine the two. */
- if (XTYPE (current_buffer->undo_list) == Lisp_Cons)
+ if (CONSP (current_buffer->undo_list))
{
Lisp_Object elt;
- elt = XCONS (current_buffer->undo_list)->car;
- if (XTYPE (elt) == Lisp_Cons
- && XTYPE (XCONS (elt)->car) == Lisp_Int
- && XTYPE (XCONS (elt)->cdr) == Lisp_Int
- && XINT (XCONS (elt)->cdr) == XINT (beg))
+ elt = XCAR (current_buffer->undo_list);
+ if (CONSP (elt)
+ && INTEGERP (XCAR (elt))
+ && INTEGERP (XCDR (elt))
+ && XINT (XCDR (elt)) == beg)
{
- XSETINT (XCONS (elt)->cdr, XINT (beg) + XINT (length));
+ XSETCDR (elt, make_number (beg + length));
return;
}
}
- lbeg = beg;
- XSET (lend, Lisp_Int, XINT (beg) + XINT (length));
+ XSETFASTINT (lbeg, beg);
+ XSETINT (lend, beg + length);
current_buffer->undo_list = Fcons (Fcons (lbeg, lend),
current_buffer->undo_list);
}
/* Record that a deletion is about to take place,
- for LENGTH characters at location BEG. */
+ of the characters in STRING, at location BEG. */
-record_delete (beg, length)
- int beg, length;
+void
+record_delete (beg, string)
+ int beg;
+ Lisp_Object string;
{
- Lisp_Object lbeg, lend, sbeg;
+ Lisp_Object sbeg;
if (EQ (current_buffer->undo_list, Qt))
return;
- if (current_buffer != XBUFFER (last_undo_buffer))
- Fundo_boundary ();
- XSET (last_undo_buffer, Lisp_Buffer, current_buffer);
+ if (PT == beg + SCHARS (string))
+ {
+ XSETINT (sbeg, -beg);
+ record_point (PT);
+ }
+ else
+ {
+ XSETFASTINT (sbeg, beg);
+ record_point (beg);
+ }
- if (MODIFF <= current_buffer->save_modified)
- record_first_change ();
+ current_buffer->undo_list
+ = Fcons (Fcons (string, sbeg), current_buffer->undo_list);
+}
- if (point == beg + length)
- XSET (sbeg, Lisp_Int, -beg);
- else
- XFASTINT (sbeg) = beg;
- XFASTINT (lbeg) = beg;
- XFASTINT (lend) = beg + length;
+/* Record the fact that MARKER is about to be adjusted by ADJUSTMENT.
+ This is done only when a marker points within text being deleted,
+ because that's the only case where an automatic marker adjustment
+ won't be inverted automatically by undoing the buffer modification. */
- /* If point isn't at start of deleted range, record where it is. */
- if (PT != XFASTINT (sbeg))
- current_buffer->undo_list
- = Fcons (make_number (PT), current_buffer->undo_list);
+void
+record_marker_adjustment (marker, adjustment)
+ Lisp_Object marker;
+ int adjustment;
+{
+ if (EQ (current_buffer->undo_list, Qt))
+ return;
+
+ /* Allocate a cons cell to be the undo boundary after this command. */
+ if (NILP (pending_boundary))
+ pending_boundary = Fcons (Qnil, Qnil);
+
+ if (!BUFFERP (last_undo_buffer)
+ || current_buffer != XBUFFER (last_undo_buffer))
+ Fundo_boundary ();
+ XSETBUFFER (last_undo_buffer, current_buffer);
current_buffer->undo_list
- = Fcons (Fcons (Fbuffer_substring (lbeg, lend), sbeg),
+ = Fcons (Fcons (marker, make_number (adjustment)),
current_buffer->undo_list);
}
/* Record that a replacement is about to take place,
for LENGTH characters at location BEG.
- The replacement does not change the number of characters. */
+ The replacement must not change the number of characters. */
+void
record_change (beg, length)
int beg, length;
{
- record_delete (beg, length);
+ record_delete (beg, make_buffer_string (beg, beg + length, 1));
record_insert (beg, length);
}
\f
Record the file modification date so that when undoing this entry
we can tell whether it is obsolete because the file was saved again. */
+void
record_first_change ()
{
Lisp_Object high, low;
- XFASTINT (high) = (current_buffer->modtime >> 16) & 0xffff;
- XFASTINT (low) = current_buffer->modtime & 0xffff;
+ struct buffer *base_buffer = current_buffer;
+
+ if (EQ (current_buffer->undo_list, Qt))
+ return;
+
+ if (!BUFFERP (last_undo_buffer)
+ || current_buffer != XBUFFER (last_undo_buffer))
+ Fundo_boundary ();
+ XSETBUFFER (last_undo_buffer, current_buffer);
+
+ if (base_buffer->base_buffer)
+ base_buffer = base_buffer->base_buffer;
+
+ XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff);
+ XSETFASTINT (low, base_buffer->modtime & 0xffff);
current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list);
}
/* Record a change in property PROP (whose old value was VAL)
for LENGTH characters starting at position BEG in BUFFER. */
+void
record_property_change (beg, length, prop, value, buffer)
int beg, length;
Lisp_Object prop, value, buffer;
struct buffer *obuf = current_buffer;
int boundary = 0;
- if (EQ (current_buffer->undo_list, Qt))
+ if (EQ (XBUFFER (buffer)->undo_list, Qt))
return;
+ /* Allocate a cons cell to be the undo boundary after this command. */
+ if (NILP (pending_boundary))
+ pending_boundary = Fcons (Qnil, Qnil);
+
if (!EQ (buffer, last_undo_buffer))
boundary = 1;
last_undo_buffer = buffer;
if (boundary)
Fundo_boundary ();
- if (MODIFF <= current_buffer->save_modified)
+ if (MODIFF <= SAVE_MODIFF)
record_first_change ();
- XSET (lbeg, Lisp_Int, beg);
- XSET (lend, Lisp_Int, beg + length);
+ XSETINT (lbeg, beg);
+ XSETINT (lend, beg + length);
entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend))));
current_buffer->undo_list = Fcons (entry, current_buffer->undo_list);
}
DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0,
- "Mark a boundary between units of undo.\n\
-An undo command will stop at this point,\n\
-but another undo command will undo to the previous boundary.")
- ()
+ doc: /* Mark a boundary between units of undo.
+An undo command will stop at this point,
+but another undo command will undo to the previous boundary. */)
+ ()
{
Lisp_Object tem;
if (EQ (current_buffer->undo_list, Qt))
return Qnil;
tem = Fcar (current_buffer->undo_list);
if (!NILP (tem))
- current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list);
+ {
+ /* One way or another, cons nil onto the front of the undo list. */
+ if (!NILP (pending_boundary))
+ {
+ /* If we have preallocated the cons cell to use here,
+ use that one. */
+ XSETCDR (pending_boundary, current_buffer->undo_list);
+ current_buffer->undo_list = pending_boundary;
+ pending_boundary = Qnil;
+ }
+ else
+ current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list);
+ }
return Qnil;
}
If the first element is an undo boundary, skip past it.
Skip, skip, skip the undo, skip, skip, skip the undo,
- Skip, skip, skip the undo, skip to the undo bound'ry.
+ Skip, skip, skip the undo, skip to the undo bound'ry.
(Get it? "Skip to my Loo?") */
- if (XTYPE (next) == Lisp_Cons
- && NILP (XCONS (next)->car))
+ if (CONSP (next) && NILP (XCAR (next)))
{
/* Add in the space occupied by this element and its chain link. */
size_so_far += sizeof (struct Lisp_Cons);
/* Advance to next element. */
prev = next;
- next = XCONS (next)->cdr;
+ next = XCDR (next);
}
- while (XTYPE (next) == Lisp_Cons
- && ! NILP (XCONS (next)->car))
+ while (CONSP (next) && ! NILP (XCAR (next)))
{
Lisp_Object elt;
- elt = XCONS (next)->car;
+ elt = XCAR (next);
/* Add in the space occupied by this element and its chain link. */
size_so_far += sizeof (struct Lisp_Cons);
- if (XTYPE (elt) == Lisp_Cons)
+ if (CONSP (elt))
{
size_so_far += sizeof (struct Lisp_Cons);
- if (XTYPE (XCONS (elt)->car) == Lisp_String)
+ if (STRINGP (XCAR (elt)))
size_so_far += (sizeof (struct Lisp_String) - 1
- + XSTRING (XCONS (elt)->car)->size);
+ + SCHARS (XCAR (elt)));
}
/* Advance to next element. */
prev = next;
- next = XCONS (next)->cdr;
+ next = XCDR (next);
}
- if (XTYPE (next) == Lisp_Cons)
+ if (CONSP (next))
last_boundary = prev;
- while (XTYPE (next) == Lisp_Cons)
+ while (CONSP (next))
{
Lisp_Object elt;
- elt = XCONS (next)->car;
+ elt = XCAR (next);
/* When we get to a boundary, decide whether to truncate
either before or after it. The lower threshold, MINSIZE,
/* Add in the space occupied by this element and its chain link. */
size_so_far += sizeof (struct Lisp_Cons);
- if (XTYPE (elt) == Lisp_Cons)
+ if (CONSP (elt))
{
size_so_far += sizeof (struct Lisp_Cons);
- if (XTYPE (XCONS (elt)->car) == Lisp_String)
+ if (STRINGP (XCAR (elt)))
size_so_far += (sizeof (struct Lisp_String) - 1
- + XSTRING (XCONS (elt)->car)->size);
+ + SCHARS (XCAR (elt)));
}
/* Advance to next element. */
prev = next;
- next = XCONS (next)->cdr;
+ next = XCDR (next);
}
/* If we scanned the whole list, it is short enough; don't change it. */
/* Truncate at the boundary where we decided to truncate. */
if (!NILP (last_boundary))
{
- XCONS (last_boundary)->cdr = Qnil;
+ XSETCDR (last_boundary, Qnil);
return list;
}
else
}
\f
DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0,
- "Undo N records from the front of the list LIST.\n\
-Return what remains of the list.")
- (n, list)
+ doc: /* Undo N records from the front of the list LIST.
+Return what remains of the list. */)
+ (n, list)
Lisp_Object n, list;
{
- int count = specpdl_ptr - specpdl;
- register int arg = XINT (n);
+ struct gcpro gcpro1, gcpro2;
+ Lisp_Object next;
+ int count = SPECPDL_INDEX ();
+ register int arg;
+
#if 0 /* This is a good feature, but would make undo-start
unable to do what is expected. */
Lisp_Object tem;
list = Fcdr (list);
#endif
- /* Don't let read-only properties interfere with undo. */
+ CHECK_NUMBER (n);
+ arg = XINT (n);
+ next = Qnil;
+ GCPRO2 (next, list);
+
+ /* In a writable buffer, enable undoing read-only text that is so
+ because of text properties. */
if (NILP (current_buffer->read_only))
specbind (Qinhibit_read_only, Qt);
+ /* Don't let `intangible' properties interfere with undo. */
+ specbind (Qinhibit_point_motion_hooks, Qt);
+
while (arg > 0)
{
- while (1)
+ while (CONSP (list))
{
- Lisp_Object next;
- next = Fcar (list);
- list = Fcdr (list);
+ next = XCAR (list);
+ list = XCDR (list);
/* Exit inner loop at undo boundary. */
if (NILP (next))
break;
/* Handle an integer by setting point to that value. */
- if (XTYPE (next) == Lisp_Int)
+ if (INTEGERP (next))
SET_PT (clip_to_bounds (BEGV, XINT (next), ZV));
- else if (XTYPE (next) == Lisp_Cons)
+ else if (CONSP (next))
{
Lisp_Object car, cdr;
- car = Fcar (next);
- cdr = Fcdr (next);
+ car = XCAR (next);
+ cdr = XCDR (next);
if (EQ (car, Qt))
{
/* Element (t high . low) records previous modtime. */
Lisp_Object high, low;
int mod_time;
+ struct buffer *base_buffer = current_buffer;
high = Fcar (cdr);
low = Fcdr (cdr);
mod_time = (XFASTINT (high) << 16) + XFASTINT (low);
+
+ if (current_buffer->base_buffer)
+ base_buffer = current_buffer->base_buffer;
+
/* If this records an obsolete save
(not matching the actual disk file)
then don't mark unmodified. */
- if (mod_time != current_buffer->modtime)
- break;
+ if (mod_time != base_buffer->modtime)
+ continue;
#ifdef CLASH_DETECTION
Funlock_buffer ();
#endif /* CLASH_DETECTION */
Fset_buffer_modified_p (Qnil);
}
-#ifdef USE_TEXT_PROPERTIES
else if (EQ (car, Qnil))
{
/* Element (nil prop val beg . end) is property change. */
Fput_text_property (beg, end, prop, val, Qnil);
}
-#endif /* USE_TEXT_PROPERTIES */
- else if (XTYPE (car) == Lisp_Int && XTYPE (cdr) == Lisp_Int)
+ else if (INTEGERP (car) && INTEGERP (cdr))
{
/* Element (BEG . END) means range was inserted. */
- Lisp_Object end;
if (XINT (car) < BEGV
|| XINT (cdr) > ZV)
Fgoto_char (car);
Fdelete_region (car, cdr);
}
- else if (XTYPE (car) == Lisp_String && XTYPE (cdr) == Lisp_Int)
+ else if (STRINGP (car) && INTEGERP (cdr))
{
/* Element (STRING . POS) means STRING was deleted. */
Lisp_Object membuf;
error ("Changes to be undone are outside visible portion of buffer");
SET_PT (pos);
- /* Insert before markers so that if the mark is
- currently on the boundary of this deletion, it
- ends up on the other side of the now-undeleted
- text from point. Since undo doesn't even keep
- track of the mark, this isn't really necessary,
- but it may lead to better behavior in certain
- situations. */
- Finsert_before_markers (1, &membuf);
+ /* Now that we record marker adjustments
+ (caused by deletion) for undo,
+ we should always insert after markers,
+ so that undoing the marker adjustments
+ put the markers back in the right place. */
+ Finsert (1, &membuf);
SET_PT (pos);
}
}
+ else if (MARKERP (car) && INTEGERP (cdr))
+ {
+ /* (MARKER . INTEGER) means a marker MARKER
+ was adjusted by INTEGER. */
+ if (XMARKER (car)->buffer)
+ Fset_marker (car,
+ make_number (marker_position (car) - XINT (cdr)),
+ Fmarker_buffer (car));
+ }
}
}
arg--;
}
+ UNGCPRO;
return unbind_to (count, list);
}
+void
syms_of_undo ()
{
Qinhibit_read_only = intern ("inhibit-read-only");
staticpro (&Qinhibit_read_only);
+ pending_boundary = Qnil;
+ staticpro (&pending_boundary);
+
defsubr (&Sprimitive_undo);
defsubr (&Sundo_boundary);
}