src/cmds.c

   1 /* Simple built-in editing commands.
   2
   3 Copyright (C) 1985, 1993-1998, 2001-2013 Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software: you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation, either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20
  21 #include <config.h>
  22
  23 #include "lisp.h"
  24 #include "commands.h"
  25 #include "character.h"
  26 #include "buffer.h"
  27 #include "syntax.h"
  28 #include "window.h"
  29 #include "keyboard.h"
  30 #include "keymap.h"
  31 #include "dispextern.h"
  32 #include "frame.h"
  33
  34 static Lisp_Object Qkill_forward_chars, Qkill_backward_chars;
  35
  36 /* A possible value for a buffer's overwrite-mode variable.  */
  37 static Lisp_Object Qoverwrite_mode_binary;
  38
  39 static int internal_self_insert (int, EMACS_INT);
  40 \f
  41 DEFUN ("forward-point", Fforward_point, Sforward_point, 1, 1, 0,
  42        doc: /* Return buffer position N characters after (before if N negative) point.  */)
  43   (Lisp_Object n)
  44 {
  45   CHECK_NUMBER (n);
  46
  47   return make_number (PT + XINT (n));
  48 }
  49
  50 /* Add N to point; or subtract N if FORWARD is false.  N defaults to 1.
  51    Validate the new location.  Return nil.  */
  52 static Lisp_Object
  53 move_point (Lisp_Object n, bool forward)
  54 {
  55   /* This used to just set point to point + XINT (n), and then check
  56      to see if it was within boundaries.  But now that SET_PT can
  57      potentially do a lot of stuff (calling entering and exiting
  58      hooks, etcetera), that's not a good approach.  So we validate the
  59      proposed position, then set point.  */
  60
  61   EMACS_INT new_point;
  62
  63   if (NILP (n))
  64     XSETFASTINT (n, 1);
  65   else
  66     CHECK_NUMBER (n);
  67
  68   new_point = PT + (forward ? XINT (n) : - XINT (n));
  69
  70   if (new_point < BEGV)
  71     {
  72       SET_PT (BEGV);
  73       xsignal0 (Qbeginning_of_buffer);
  74     }
  75   if (new_point > ZV)
  76     {
  77       SET_PT (ZV);
  78       xsignal0 (Qend_of_buffer);
  79     }
  80
  81   SET_PT (new_point);
  82   return Qnil;
  83 }
  84
  85 DEFUN ("forward-char", Fforward_char, Sforward_char, 0, 1, "^p",
  86        doc: /* Move point N characters forward (backward if N is negative).
  87 On reaching end or beginning of buffer, stop and signal error.
  88 Interactively, N is the numeric prefix argument.
  89
  90 Depending on the bidirectional context, the movement may be to the
  91 right or to the left on the screen.  This is in contrast with
  92 \\[right-char], which see.  */)
  93   (Lisp_Object n)
  94 {
  95   return move_point (n, 1);
  96 }
  97
  98 DEFUN ("backward-char", Fbackward_char, Sbackward_char, 0, 1, "^p",
  99        doc: /* Move point N characters backward (forward if N is negative).
 100 On attempt to pass beginning or end of buffer, stop and signal error.
 101 Interactively, N is the numeric prefix argument.
 102
 103 Depending on the bidirectional context, the movement may be to the
 104 right or to the left on the screen.  This is in contrast with
 105 \\[left-char], which see.  */)
 106   (Lisp_Object n)
 107 {
 108   return move_point (n, 0);
 109 }
 110
 111 DEFUN ("forward-line", Fforward_line, Sforward_line, 0, 1, "^p",
 112        doc: /* Move N lines forward (backward if N is negative).
 113 Precisely, if point is on line I, move to the start of line I + N
 114 \("start of line" in the logical order).
 115 If there isn't room, go as far as possible (no error).
 116 Returns the count of lines left to move.  If moving forward,
 117 that is N - number of lines moved; if backward, N + number moved.
 118 With positive N, a non-empty line at the end counts as one line
 119 successfully moved (for the return value).  */)
 120   (Lisp_Object n)
 121 {
 122   ptrdiff_t opoint = PT, opoint_byte = PT_BYTE;
 123   ptrdiff_t pos, pos_byte;
 124   EMACS_INT count, shortage;
 125
 126   if (NILP (n))
 127     count = 1;
 128   else
 129     {
 130       CHECK_NUMBER (n);
 131       count = XINT (n);
 132     }
 133
 134   if (count <= 0)
 135     shortage = scan_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, count - 1, 1);
 136   else
 137     shortage = scan_newline (PT, PT_BYTE, ZV, ZV_BYTE, count, 1);
 138
 139   /* Since scan_newline does TEMP_SET_PT_BOTH,
 140      and we want to set PT "for real",
 141      go back to the old point and then come back here.  */
 142   pos = PT;
 143   pos_byte = PT_BYTE;
 144   TEMP_SET_PT_BOTH (opoint, opoint_byte);
 145   SET_PT_BOTH (pos, pos_byte);
 146
 147   if (shortage > 0
 148       && (count <= 0
 149           || (ZV > BEGV
 150               && PT != opoint
 151               && (FETCH_BYTE (PT_BYTE - 1) != '\n'))))
 152     shortage--;
 153
 154   return make_number (count <= 0 ? - shortage : shortage);
 155 }
 156
 157 DEFUN ("beginning-of-line", Fbeginning_of_line, Sbeginning_of_line, 0, 1, "^p",
 158        doc: /* Move point to beginning of current line (in the logical order).
 159 With argument N not nil or 1, move forward N - 1 lines first.
 160 If point reaches the beginning or end of buffer, it stops there.
 161
 162 This function constrains point to the current field unless this moves
 163 point to a different line than the original, unconstrained result.
 164 If N is nil or 1, and a front-sticky field starts at point, the point
 165 does not move.  To ignore field boundaries bind
 166 `inhibit-field-text-motion' to t, or use the `forward-line' function
 167 instead.  For instance, `(forward-line 0)' does the same thing as
 168 `(beginning-of-line)', except that it ignores field boundaries.  */)
 169   (Lisp_Object n)
 170 {
 171   if (NILP (n))
 172     XSETFASTINT (n, 1);
 173   else
 174     CHECK_NUMBER (n);
 175
 176   SET_PT (XINT (Fline_beginning_position (n)));
 177
 178   return Qnil;
 179 }
 180
 181 DEFUN ("end-of-line", Fend_of_line, Send_of_line, 0, 1, "^p",
 182        doc: /* Move point to end of current line (in the logical order).
 183 With argument N not nil or 1, move forward N - 1 lines first.
 184 If point reaches the beginning or end of buffer, it stops there.
 185 To ignore intangibility, bind `inhibit-point-motion-hooks' to t.
 186
 187 This function constrains point to the current field unless this moves
 188 point to a different line than the original, unconstrained result.  If
 189 N is nil or 1, and a rear-sticky field ends at point, the point does
 190 not move.  To ignore field boundaries bind `inhibit-field-text-motion'
 191 to t.  */)
 192   (Lisp_Object n)
 193 {
 194   ptrdiff_t newpos;
 195
 196   if (NILP (n))
 197     XSETFASTINT (n, 1);
 198   else
 199     CHECK_NUMBER (n);
 200
 201   while (1)
 202     {
 203       newpos = XINT (Fline_end_position (n));
 204       SET_PT (newpos);
 205
 206       if (PT > newpos
 207           && FETCH_CHAR (PT - 1) == '\n')
 208         {
 209           /* If we skipped over a newline that follows
 210              an invisible intangible run,
 211              move back to the last tangible position
 212              within the line.  */
 213
 214           SET_PT (PT - 1);
 215           break;
 216         }
 217       else if (PT > newpos && PT < ZV
 218                && FETCH_CHAR (PT) != '\n')
 219         /* If we skipped something intangible
 220            and now we're not really at eol,
 221            keep going.  */
 222         n = make_number (1);
 223       else
 224         break;
 225     }
 226
 227   return Qnil;
 228 }
 229
 230 DEFUN ("delete-char", Fdelete_char, Sdelete_char, 1, 2, "p\nP",
 231        doc: /* Delete the following N characters (previous if N is negative).
 232 Optional second arg KILLFLAG non-nil means kill instead (save in kill ring).
 233 Interactively, N is the prefix arg, and KILLFLAG is set if
 234 N was explicitly specified.
 235
 236 The command `delete-forward-char' is preferable for interactive use.  */)
 237   (Lisp_Object n, Lisp_Object killflag)
 238 {
 239   EMACS_INT pos;
 240
 241   CHECK_NUMBER (n);
 242
 243   pos = PT + XINT (n);
 244   if (NILP (killflag))
 245     {
 246       if (XINT (n) < 0)
 247         {
 248           if (pos < BEGV)
 249             xsignal0 (Qbeginning_of_buffer);
 250           else
 251             del_range (pos, PT);
 252         }
 253       else
 254         {
 255           if (pos > ZV)
 256             xsignal0 (Qend_of_buffer);
 257           else
 258             del_range (PT, pos);
 259         }
 260     }
 261   else
 262     {
 263       call1 (Qkill_forward_chars, n);
 264     }
 265   return Qnil;
 266 }
 267
 268 static int nonundocount;
 269
 270 /* Note that there's code in command_loop_1 which typically avoids
 271    calling this.  */
 272 DEFUN ("self-insert-command", Fself_insert_command, Sself_insert_command, 1, 1, "p",
 273        doc: /* Insert the character you type.
 274 Whichever character you type to run this command is inserted.
 275 Before insertion, `expand-abbrev' is executed if the inserted character does
 276 not have word syntax and the previous character in the buffer does.
 277 After insertion, the value of `auto-fill-function' is called if the
 278 `auto-fill-chars' table has a non-nil value for the inserted character.
 279 At the end, it runs `post-self-insert-hook'.  */)
 280   (Lisp_Object n)
 281 {
 282   bool remove_boundary = 1;
 283   CHECK_NATNUM (n);
 284
 285   if (!EQ (Vthis_command, KVAR (current_kboard, Vlast_command)))
 286     nonundocount = 0;
 287
 288   if (NILP (Vexecuting_kbd_macro)
 289       && !EQ (minibuf_window, selected_window))
 290     {
 291       if (nonundocount <= 0 || nonundocount >= 20)
 292         {
 293           remove_boundary = 0;
 294           nonundocount = 0;
 295         }
 296       nonundocount++;
 297     }
 298
 299   if (remove_boundary
 300       && CONSP (BVAR (current_buffer, undo_list))
 301       && NILP (XCAR (BVAR (current_buffer, undo_list)))
 302       /* Only remove auto-added boundaries, not boundaries
 303          added be explicit calls to undo-boundary.  */
 304       && EQ (BVAR (current_buffer, undo_list), last_undo_boundary))
 305     /* Remove the undo_boundary that was just pushed.  */
 306     bset_undo_list (current_buffer, XCDR (BVAR (current_buffer, undo_list)));
 307
 308   /* Barf if the key that invoked this was not a character.  */
 309   if (!CHARACTERP (last_command_event))
 310     bitch_at_user ();
 311   {
 312     int character = translate_char (Vtranslation_table_for_input,
 313                                     XINT (last_command_event));
 314     int val = internal_self_insert (character, XFASTINT (n));
 315     if (val == 2)
 316       nonundocount = 0;
 317     frame_make_pointer_invisible ();
 318   }
 319
 320   return Qnil;
 321 }
 322
 323 /* Insert N times character C
 324
 325    If this insertion is suitable for direct output (completely simple),
 326    return 0.  A value of 1 indicates this *might* not have been simple.
 327    A value of 2 means this did things that call for an undo boundary.  */
 328
 329 static Lisp_Object Qexpand_abbrev;
 330 static Lisp_Object Qpost_self_insert_hook;
 331
 332 static int
 333 internal_self_insert (int c, EMACS_INT n)
 334 {
 335   int hairy = 0;
 336   Lisp_Object tem;
 337   register enum syntaxcode synt;
 338   Lisp_Object overwrite;
 339   /* Length of multi-byte form of C.  */
 340   int len;
 341   /* Working buffer and pointer for multi-byte form of C.  */
 342   unsigned char str[MAX_MULTIBYTE_LENGTH];
 343   ptrdiff_t chars_to_delete = 0;
 344   ptrdiff_t spaces_to_insert = 0;
 345
 346   overwrite = BVAR (current_buffer, overwrite_mode);
 347   if (!NILP (Vbefore_change_functions) || !NILP (Vafter_change_functions))
 348     hairy = 1;
 349
 350   /* At first, get multi-byte form of C in STR.  */
 351   if (!NILP (BVAR (current_buffer, enable_multibyte_characters)))
 352     {
 353       len = CHAR_STRING (c, str);
 354       if (len == 1)
 355         /* If C has modifier bits, this makes C an appropriate
 356            one-byte char.  */
 357         c = *str;
 358     }
 359   else
 360     {
 361       str[0] = (SINGLE_BYTE_CHAR_P (c)
 362                 ? c
 363                 : multibyte_char_to_unibyte (c));
 364       len = 1;
 365     }
 366   if (!NILP (overwrite)
 367       && PT < ZV)
 368     {
 369       /* In overwrite-mode, we substitute a character at point (C2,
 370          hereafter) by C.  For that, we delete C2 in advance.  But,
 371          just substituting C2 by C may move a remaining text in the
 372          line to the right or to the left, which is not preferable.
 373          So we insert more spaces or delete more characters in the
 374          following cases: if C is narrower than C2, after deleting C2,
 375          we fill columns with spaces, if C is wider than C2, we delete
 376          C2 and several characters following C2.  */
 377
 378       /* This is the character after point.  */
 379       int c2 = FETCH_CHAR (PT_BYTE);
 380
 381       int cwidth;
 382
 383       /* Overwriting in binary-mode always replaces C2 by C.
 384          Overwriting in textual-mode doesn't always do that.
 385          It inserts newlines in the usual way,
 386          and inserts any character at end of line
 387          or before a tab if it doesn't use the whole width of the tab.  */
 388       if (EQ (overwrite, Qoverwrite_mode_binary))
 389         chars_to_delete = min (n, PTRDIFF_MAX);
 390       else if (c != '\n' && c2 != '\n'
 391                && (cwidth = XFASTINT (Fchar_width (make_number (c)))) != 0)
 392         {
 393           ptrdiff_t pos = PT;
 394           ptrdiff_t pos_byte = PT_BYTE;
 395           ptrdiff_t curcol = current_column ();
 396
 397           if (n <= (min (MOST_POSITIVE_FIXNUM, PTRDIFF_MAX) - curcol) / cwidth)
 398             {
 399               /* Column the cursor should be placed at after this insertion.
 400                  The value should be calculated only when necessary.  */
 401               ptrdiff_t target_clm = curcol + n * cwidth;
 402
 403               /* The actual cursor position after the trial of moving
 404                  to column TARGET_CLM.  It is greater than TARGET_CLM
 405                  if the TARGET_CLM is middle of multi-column
 406                  character.  In that case, the new point is set after
 407                  that character.  */
 408               ptrdiff_t actual_clm
 409                 = XFASTINT (Fmove_to_column (make_number (target_clm), Qnil));
 410
 411               chars_to_delete = PT - pos;
 412
 413               if (actual_clm > target_clm)
 414                 {
 415                   /* We will delete too many columns.  Let's fill columns
 416                      by spaces so that the remaining text won't move.  */
 417                   ptrdiff_t actual = PT_BYTE;
 418                   DEC_POS (actual);
 419                   if (FETCH_CHAR (actual) == '\t')
 420                     /* Rather than add spaces, let's just keep the tab. */
 421                     chars_to_delete--;
 422                   else
 423                     spaces_to_insert = actual_clm - target_clm;
 424                 }
 425
 426               SET_PT_BOTH (pos, pos_byte);
 427             }
 428         }
 429       hairy = 2;
 430     }
 431
 432   synt = SYNTAX (c);
 433
 434   if (!NILP (BVAR (current_buffer, abbrev_mode))
 435       && synt != Sword
 436       && NILP (BVAR (current_buffer, read_only))
 437       && PT > BEGV
 438       && (SYNTAX (!NILP (BVAR (current_buffer, enable_multibyte_characters))
 439                   ? XFASTINT (Fprevious_char ())
 440                   : UNIBYTE_TO_CHAR (XFASTINT (Fprevious_char ())))
 441           == Sword))
 442     {
 443       EMACS_INT modiff = MODIFF;
 444       Lisp_Object sym;
 445
 446       sym = call0 (Qexpand_abbrev);
 447
 448       /* If we expanded an abbrev which has a hook,
 449          and the hook has a non-nil `no-self-insert' property,
 450          return right away--don't really self-insert.  */
 451       if (SYMBOLP (sym) && ! NILP (sym)
 452           && ! NILP (XSYMBOL (sym)->function)
 453           && SYMBOLP (XSYMBOL (sym)->function))
 454         {
 455           Lisp_Object prop;
 456           prop = Fget (XSYMBOL (sym)->function, intern ("no-self-insert"));
 457           if (! NILP (prop))
 458             return 1;
 459         }
 460
 461       if (MODIFF != modiff)
 462         hairy = 2;
 463     }
 464
 465   if (chars_to_delete)
 466     {
 467       int mc = ((NILP (BVAR (current_buffer, enable_multibyte_characters))
 468                  && SINGLE_BYTE_CHAR_P (c))
 469                 ? UNIBYTE_TO_CHAR (c) : c);
 470       Lisp_Object string = Fmake_string (make_number (n), make_number (mc));
 471
 472       if (spaces_to_insert)
 473         {
 474           tem = Fmake_string (make_number (spaces_to_insert),
 475                               make_number (' '));
 476           string = concat2 (string, tem);
 477         }
 478
 479       replace_range (PT, PT + chars_to_delete, string, 1, 1, 1);
 480       Fforward_char (make_number (n + spaces_to_insert));
 481     }
 482   else if (n > 1)
 483     {
 484       USE_SAFE_ALLOCA;
 485       char *strn, *p;
 486       SAFE_NALLOCA (strn, len, n);
 487       for (p = strn; n > 0; n--, p += len)
 488         memcpy (p, str, len);
 489       insert_and_inherit (strn, p - strn);
 490       SAFE_FREE ();
 491     }
 492   else if (n > 0)
 493     insert_and_inherit ((char *) str, len);
 494
 495   if ((CHAR_TABLE_P (Vauto_fill_chars)
 496        ? !NILP (CHAR_TABLE_REF (Vauto_fill_chars, c))
 497        : (c == ' ' || c == '\n'))
 498       && !NILP (BVAR (current_buffer, auto_fill_function)))
 499     {
 500       Lisp_Object auto_fill_result;
 501
 502       if (c == '\n')
 503         /* After inserting a newline, move to previous line and fill
 504            that.  Must have the newline in place already so filling and
 505            justification, if any, know where the end is going to be.  */
 506         SET_PT_BOTH (PT - 1, PT_BYTE - 1);
 507       auto_fill_result = call0 (BVAR (current_buffer, auto_fill_function));
 508       /* Test PT < ZV in case the auto-fill-function is strange.  */
 509       if (c == '\n' && PT < ZV)
 510         SET_PT_BOTH (PT + 1, PT_BYTE + 1);
 511       if (!NILP (auto_fill_result))
 512         hairy = 2;
 513     }
 514
 515   /* Run hooks for electric keys.  */
 516   Frun_hooks (1, &Qpost_self_insert_hook);
 517
 518   return hairy;
 519 }
 520 \f
 521 /* module initialization */
 522
 523 void
 524 syms_of_cmds (void)
 525 {
 526   DEFSYM (Qkill_backward_chars, "kill-backward-chars");
 527   DEFSYM (Qkill_forward_chars, "kill-forward-chars");
 528   DEFSYM (Qoverwrite_mode_binary, "overwrite-mode-binary");
 529   DEFSYM (Qexpand_abbrev, "expand-abbrev");
 530   DEFSYM (Qpost_self_insert_hook, "post-self-insert-hook");
 531
 532   DEFVAR_LISP ("post-self-insert-hook", Vpost_self_insert_hook,
 533                doc: /* Hook run at the end of `self-insert-command'.
 534 This is run after inserting the character.  */);
 535   Vpost_self_insert_hook = Qnil;
 536
 537   defsubr (&Sforward_point);
 538   defsubr (&Sforward_char);
 539   defsubr (&Sbackward_char);
 540   defsubr (&Sforward_line);
 541   defsubr (&Sbeginning_of_line);
 542   defsubr (&Send_of_line);
 543
 544   defsubr (&Sdelete_char);
 545   defsubr (&Sself_insert_command);
 546 }
 547
 548 void
 549 keys_of_cmds (void)
 550 {
 551   int n;
 552
 553   nonundocount = 0;
 554   initial_define_key (global_map, Ctl ('I'), "self-insert-command");
 555   for (n = 040; n < 0177; n++)
 556     initial_define_key (global_map, n, "self-insert-command");
 557 #ifdef MSDOS
 558   for (n = 0200; n < 0240; n++)
 559     initial_define_key (global_map, n, "self-insert-command");
 560 #endif
 561   for (n = 0240; n < 0400; n++)
 562     initial_define_key (global_map, n, "self-insert-command");
 563
 564   initial_define_key (global_map, Ctl ('A'), "beginning-of-line");
 565   initial_define_key (global_map, Ctl ('B'), "backward-char");
 566   initial_define_key (global_map, Ctl ('E'), "end-of-line");
 567   initial_define_key (global_map, Ctl ('F'), "forward-char");
 568 }