dispnew.c 57.9 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Updating of data structures for redisplay.
Jim Blandy's avatar
Jim Blandy committed
2
   Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

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 1, or (at your option)
any later version.

GNU Emacs is distributed in the hope that it will be useful,
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.

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, 675 Mass Ave, Cambridge, MA 02139, USA.  */


#include <signal.h>

#include "config.h"
#include <stdio.h>
#include <ctype.h>

#include "termchar.h"
#include "termopts.h"
#include "cm.h"
#include "lisp.h"
#include "dispextern.h"
#include "buffer.h"
#include "screen.h"
#include "window.h"
#include "commands.h"
#include "disptab.h"
#include "indent.h"

Jim Blandy's avatar
Jim Blandy committed
39 40 41
#include "systerm.h"
#include "systime.h"

Jim Blandy's avatar
Jim Blandy committed
42 43 44 45 46 47 48 49 50 51 52 53 54 55
#ifdef HAVE_X_WINDOWS
#include "xterm.h"
#endif	/* HAVE_X_WINDOWS */

#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))

#ifndef PENDING_OUTPUT_COUNT
/* Get number of chars of output now in the buffer of a stdio stream.
   This ought to be built in in stdio, but it isn't.
   Some s- files override this because their stdio internals differ.  */
#define PENDING_OUTPUT_COUNT(FILE) ((FILE)->_ptr - (FILE)->_base)
#endif

Jim Blandy's avatar
Jim Blandy committed
56 57
/* Nonzero upon entry to redisplay means do not assume anything about
   current contents of actual terminal screen; clear and redraw it.  */
Jim Blandy's avatar
Jim Blandy committed
58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98

int screen_garbaged;

/* Nonzero means last display completed.  Zero means it was preempted. */

int display_completed;

/* Lisp variable visible-bell; enables use of screen-flash
   instead of audible bell.  */

int visible_bell;

/* Invert the color of the whole screen, at a low level.  */

int inverse_video;

/* Line speed of the terminal.  */

int baud_rate;

/* nil or a symbol naming the window system under which emacs is
   running ('x is the only current possibility).  */

Lisp_Object Vwindow_system;

/* Version number of X windows: 10, 11 or nil.  */
Lisp_Object Vwindow_system_version;

/* Vector of glyph definitions.  Indexed by glyph number,
   the contents are a string which is how to output the glyph.

   If Vglyph_table is nil, a glyph is output by using its low 8 bits
   as a character code.  */

Lisp_Object Vglyph_table;

/* Display table to use for vectors that don't specify their own.  */

Lisp_Object Vstandard_display_table;

/* Nonzero means reading single-character input with prompt
Jim Blandy's avatar
Jim Blandy committed
99 100 101
   so put cursor on minibuffer after the prompt.
   positive means at end of text in echo area;
   negative means at beginning of line.  */
Jim Blandy's avatar
Jim Blandy committed
102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156
int cursor_in_echo_area;

/* The currently selected screen.
   In a single-screen version, this variable always remains 0.  */

SCREEN_PTR selected_screen;

/* In a single-screen version, the information that would otherwise
   exist inside a `struct screen' lives in the following variables instead.  */

#ifndef MULTI_SCREEN

/* Desired terminal cursor position (to show position of point),
   origin zero */

int cursX, cursY;

/* Description of current screen contents */

struct screen_glyphs *current_glyphs;

/* Description of desired screen contents */

struct screen_glyphs *desired_glyphs;

#endif /* not MULTI_SCREEN */

/* This is a vector, made larger whenever it isn't large enough,
   which is used inside `update_screen' to hold the old contents
   of the SCREEN_PHYS_LINES of the screen being updated.  */
struct screen_glyphs **ophys_lines;
/* Length of vector currently allocated.  */
int ophys_lines_length;

FILE *termscript;	/* Stdio stream being used for copy of all output.  */

struct cm Wcm;		/* Structure for info on cursor positioning */

extern short ospeed;	/* Output speed (from sg_ospeed) */

int in_display;		/* 1 if in redisplay: can't handle SIGWINCH now.  */

int delayed_size_change;  /* 1 means SIGWINCH happened when not safe.  */
int delayed_screen_height;  /* Remembered new screen height.  */
int delayed_screen_width;   /* Remembered new screen width.  */

#ifdef MULTI_SCREEN

DEFUN ("redraw-screen", Fredraw_screen, Sredraw_screen, 1, 1, 0,
  "Clear screen SCREEN and output again what is supposed to appear on it.")
  (screen)
     Lisp_Object screen;
{
  SCREEN_PTR s;

Jim Blandy's avatar
Jim Blandy committed
157
  CHECK_LIVE_SCREEN (screen, 0);
Jim Blandy's avatar
Jim Blandy committed
158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507
  s = XSCREEN (screen);
  update_begin (s);
  /*  set_terminal_modes (); */
  clear_screen ();
  update_end (s);
  fflush (stdout);
  clear_screen_records (s);
  windows_or_buffers_changed++;
  /* Mark all windows as INaccurate,
     so that every window will have its redisplay done.  */
  mark_window_display_accurate (SCREEN_ROOT_WINDOW (s), 0);
  s->garbaged = 0;
  return Qnil;
}

DEFUN ("redraw-display", Fredraw_display, Sredraw_display, 0, 0, "",
  "Redraw all screens marked as having their images garbled.")
  ()
{
  Lisp_Object screen, tail;

  for (tail = Vscreen_list; CONSP (tail); tail = XCONS (tail)->cdr)
    {
      screen = XCONS (tail)->car;
      if (XSCREEN (screen)->garbaged && XSCREEN (screen)->visible)
	Fredraw_screen (screen);
    }
  return Qnil;
}

redraw_screen (s)
     SCREEN_PTR s;
{
  Lisp_Object screen;
  XSET (screen, Lisp_Screen, s);
  Fredraw_screen (screen);
}

#else /* not MULTI_SCREEN */

DEFUN ("redraw-display", Fredraw_display, Sredraw_display, 0, 0, 0,
  "Clear screen and output again what is supposed to appear on it.")
  ()
{
  update_begin (0);
  set_terminal_modes ();
  clear_screen ();
  update_end (0);
  fflush (stdout);
  clear_screen_records (0);
  windows_or_buffers_changed++;
  /* Mark all windows as INaccurate,
     so that every window will have its redisplay done.  */
  mark_window_display_accurate (XWINDOW (minibuf_window)->prev, 0);
  return Qnil;
}

#endif /* not MULTI_SCREEN */

static struct screen_glyphs *
make_screen_glyphs (screen, empty)
     register SCREEN_PTR screen;
     int empty;
{
  register int i;
  register width = SCREEN_WIDTH (screen);
  register height = SCREEN_HEIGHT (screen);
  register struct screen_glyphs *new =
    (struct screen_glyphs *) xmalloc (sizeof (struct screen_glyphs));

  SET_GLYPHS_SCREEN (new, screen);
  new->height = height;
  new->width = width;
  new->used = (int *) xmalloc (height * sizeof (int));
  new->glyphs = (GLYPH **) xmalloc (height * sizeof (GLYPH *));
  new->highlight = (char *) xmalloc (height * sizeof (char));
  new->enable = (char *) xmalloc (height * sizeof (char));
  bzero (new->enable, height * sizeof (char));
  new->bufp = (int *) xmalloc (height * sizeof (int));

#ifdef HAVE_X_WINDOWS
  if (SCREEN_IS_X (screen))
    {
      new->nruns = (int *) xmalloc (height * sizeof (int));
      new->face_list
	= (struct run **) xmalloc (height * sizeof (struct run *));
      new->top_left_x = (short *) xmalloc (height * sizeof (short));
      new->top_left_y = (short *) xmalloc (height * sizeof (short));
      new->pix_width = (short *) xmalloc (height * sizeof (short));
      new->pix_height = (short *) xmalloc (height * sizeof (short));
    }
#endif

  if (empty)
    {
      /* Make the buffer used by decode_mode_spec.  This buffer is also
         used as temporary storage when updating the screen.  See scroll.c. */
      unsigned int total_glyphs = (width + 2) * sizeof (GLYPH);

      new->total_contents = (GLYPH *) xmalloc (total_glyphs);
      bzero (new->total_contents, total_glyphs);
    }
  else
    {
      unsigned int total_glyphs = height * (width + 2) * sizeof (GLYPH);

      new->total_contents = (GLYPH *) xmalloc (total_glyphs);
      bzero (new->total_contents, total_glyphs);
      for (i = 0; i < height; i++)
	new->glyphs[i] = new->total_contents + i * (width + 2) + 1;
    }

  return new;
}

static void
free_screen_glyphs (screen, glyphs)
     SCREEN_PTR screen;
     struct screen_glyphs *glyphs;
{
  if (glyphs->total_contents)
    free (glyphs->total_contents);

  free (glyphs->used);
  free (glyphs->glyphs);
  free (glyphs->highlight);
  free (glyphs->enable);
  free (glyphs->bufp);

#ifdef HAVE_X_WINDOWS
  if (SCREEN_IS_X (screen))
    {
      free (glyphs->nruns);
      free (glyphs->face_list);
      free (glyphs->top_left_x);
      free (glyphs->top_left_y);
      free (glyphs->pix_width);
      free (glyphs->pix_height);
    }
#endif

  free (glyphs);
}

static void
remake_screen_glyphs (screen)
     SCREEN_PTR screen;
{
  if (SCREEN_CURRENT_GLYPHS (screen))
    free_screen_glyphs (screen, SCREEN_CURRENT_GLYPHS (screen));
  if (SCREEN_DESIRED_GLYPHS (screen))
    free_screen_glyphs (screen, SCREEN_DESIRED_GLYPHS (screen));
  if (SCREEN_TEMP_GLYPHS (screen))
    free_screen_glyphs (screen, SCREEN_TEMP_GLYPHS (screen));

  if (SCREEN_MESSAGE_BUF (screen))
    SCREEN_MESSAGE_BUF (screen)
      = (char *) xrealloc (SCREEN_MESSAGE_BUF (screen),
			   SCREEN_WIDTH (screen) + 1);
  else
    SCREEN_MESSAGE_BUF (screen)
      = (char *) xmalloc (SCREEN_WIDTH (screen) + 1);

  SCREEN_CURRENT_GLYPHS (screen) = make_screen_glyphs (screen, 0);
  SCREEN_DESIRED_GLYPHS (screen) = make_screen_glyphs (screen, 0);
  SCREEN_TEMP_GLYPHS (screen) = make_screen_glyphs (screen, 1);
  SET_SCREEN_GARBAGED (screen);
}

/* Return the hash code of contents of line VPOS in screen-matrix M.  */

static int
line_hash_code (m, vpos)
     register struct screen_glyphs *m;
     int vpos;
{
  register GLYPH *body, *end;
  register int h = 0;

  if (!m->enable[vpos])
    return 0;

  /* Give all lighlighted lines the same hash code
     so as to encourage scrolling to leave them in place.  */
  if (m->highlight[vpos])
    return -1;

  body = m->glyphs[vpos];

  if (must_write_spaces)
    while (1)
      {
	GLYPH g = *body++;

	if (g == 0)
	  break;
	h = (((h << 4) + (h >> 24)) & 0x0fffffff) + g - SPACEGLYPH;
      }
  else
    while (1)
      {
	GLYPH g = *body++;

	if (g == 0)
	  break;
	h = (((h << 4) + (h >> 24)) & 0x0fffffff) + g;
      }

  if (h)
    return h;
  return 1;
}

/* Return number of characters in line in M at vpos VPOS,
   except don't count leading and trailing spaces
   unless the terminal requires those to be explicitly output.  */

static unsigned int
line_draw_cost (m, vpos)
     struct screen_glyphs *m;
     int vpos;
{
  register GLYPH *beg = m->glyphs[vpos];
  register GLYPH *end = m->glyphs[vpos] + m->used[vpos];
  register int i;
  register int tlen = GLYPH_TABLE_LENGTH;
  register Lisp_Object *tbase = GLYPH_TABLE_BASE;

  /* Ignore trailing and leading spaces if we can.  */
  if (!must_write_spaces)
    {
      while ((end != beg) && (*end == SPACEGLYPH))
	--end;
      if (end == beg)
	return (0); /* All blank line. */

      while (*beg == SPACEGLYPH)
	++beg;
    }

  /* If we don't have a glyph-table, each glyph is one character,
     so return the number of glyphs.  */
  if (tbase == 0)
    return end - beg;

  /* Otherwise, scan the glyphs and accumulate their total size in I.  */
  i = 0;
  while ((beg <= end) && *beg)
    {
      register GLYPH g = *beg++;

      if (GLYPH_SIMPLE_P (tbase, tlen, g))
	i += 1;
      else
	i += GLYPH_LENGTH (tbase, g);
    }
  return i;
}

/* The functions on this page are the interface from xdisp.c to redisplay.

   The only other interface into redisplay is through setting
   SCREEN_CURSOR_X (screen) and SCREEN_CURSOR_Y (screen)
   and SET_SCREEN_GARBAGED (screen).  */

/* cancel_line eliminates any request to display a line at position `vpos' */

cancel_line (vpos, screen)
     int vpos;
     register SCREEN_PTR screen;
{
  SCREEN_DESIRED_GLYPHS (screen)->enable[vpos] = 0;
}

clear_screen_records (screen)
     register SCREEN_PTR screen;
{
  bzero (SCREEN_CURRENT_GLYPHS (screen)->enable, SCREEN_HEIGHT (screen));
}

/* Prepare to display on line VPOS starting at HPOS within it.  */

void
get_display_line (screen, vpos, hpos)
     register SCREEN_PTR screen;
     int vpos;
     register int hpos;
{
  register struct screen_glyphs *glyphs;
  register struct screen_glyphs *desired_glyphs = SCREEN_DESIRED_GLYPHS (screen);
  register GLYPH *p;

  if (vpos < 0 || (! SCREEN_VISIBLE_P (screen)))
    abort ();

  if ((desired_glyphs->enable[vpos]) && desired_glyphs->used[vpos] > hpos)
    abort ();

  if (! desired_glyphs->enable[vpos])
    {
      desired_glyphs->used[vpos] = 0;
      desired_glyphs->highlight[vpos] = 0;
      desired_glyphs->enable[vpos] = 1;
    }

  if (hpos > desired_glyphs->used[vpos])
    {
      GLYPH *g = desired_glyphs->glyphs[vpos] + desired_glyphs->used[vpos];
      GLYPH *end = desired_glyphs->glyphs[vpos] + hpos;

      desired_glyphs->used[vpos] = hpos;
      while (g != end)
	*g++ = SPACEGLYPH;
    }
}

/* Like bcopy except never gets confused by overlap.  */

void
safe_bcopy (from, to, size)
     char *from, *to;
     int size;
{
  register char *endf;
  register char *endt;

  if (size == 0)
    return;

  /* If destination is higher in memory, and overlaps source zone,
     copy from the end.  */
  if (from < to && from + size > to)
    {
      endf = from + size;
      endt = to + size;

      /* If TO - FROM is large, then we should break the copy into
	 nonoverlapping chunks of TO - FROM bytes each.  However, if
	 TO - FROM is small, then the bcopy function call overhead
	 makes this not worth it.  The crossover point could be about
	 anywhere.  Since I don't think the obvious copy loop is ever
	 too bad, I'm trying to err in its favor.  */
      if (to - from < 64)
	{
	  do
	    *--endt = *--endf;
	  while (endf != from);
	}
      else
	{
Jim Blandy's avatar
Jim Blandy committed
508 509
	  /* Since TO - FROM >= 64, the overlap is less than SIZE,
	     so we can always safely do this loop once.  */
Jim Blandy's avatar
Jim Blandy committed
510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557
	  while (endt > to)
	    {
	      endt -= (to - from);
	      endf -= (to - from);

	      bcopy (endf, endt, to - from);
	    }
	  
	  /* If TO - FROM wasn't a multiple of SIZE, there will be a
	     little left over.  The amount left over is
	     (endt + (to - from)) - to, which is endt - from.  */
	  bcopy (from, to, endt - from);
	}
    }
  else
    bcopy (from, to, size);
}     

#if 0
void
safe_bcopy (from, to, size)
     char *from, *to;
     int size;
{
  register char *endf;
  register char *endt;

  if (size == 0)
    return;

  /* If destination is higher in memory, and overlaps source zone,
     copy from the end. */
  if (from < to && from + size > to)
    {
      endf = from + size;
      endt = to + size;

      do
	*--endt = *--endf;
      while (endf != from);

      return;
    }

  bcopy (from, to, size);
}
#endif

Jim Blandy's avatar
Jim Blandy committed
558
/* Rotate a vector of SIZE bytes right, by DISTANCE bytes.
Jim Blandy's avatar
Jim Blandy committed
559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923
   DISTANCE may be negative.  */

static void
rotate_vector (vector, size, distance)
     char *vector;
     int size;
     int distance;
{
  char *temp = (char *) alloca (size);

  if (distance < 0)
    distance += size;

  bcopy (vector, temp + distance, size - distance);
  bcopy (vector + size - distance, temp, distance);
  bcopy (temp, vector, size);
}

/* Scroll lines from vpos FROM up to but not including vpos END
   down by AMOUNT lines (AMOUNT may be negative).
   Returns nonzero if done, zero if terminal cannot scroll them.  */

int
scroll_screen_lines (screen, from, end, amount)
     register SCREEN_PTR screen;
     int from, end, amount;
{
  register int i;
  register struct screen_glyphs *current_screen
    = SCREEN_CURRENT_GLYPHS (screen);

  if (!line_ins_del_ok)
    return 0;

  if (amount == 0)
    return 1;

  if (amount > 0)
    {
      update_begin (screen);
      set_terminal_window (end + amount);
      if (!scroll_region_ok)
	ins_del_lines (end, -amount);
      ins_del_lines (from, amount);
      set_terminal_window (0);

      rotate_vector (current_screen->glyphs + from,
		     sizeof (GLYPH *) * (end + amount - from),
		     amount * sizeof (GLYPH *));

      safe_bcopy (current_screen->used + from,
		  current_screen->used + from + amount,
		  (end - from) * sizeof current_screen->used[0]);

      safe_bcopy (current_screen->highlight + from,
		  current_screen->highlight + from + amount,
		  (end - from) * sizeof current_screen->highlight[0]);

      safe_bcopy (current_screen->enable + from,
		  current_screen->enable + from + amount,
		  (end - from) * sizeof current_screen->enable[0]);

      /* Mark the lines made empty by scrolling as enabled, empty and
	 normal video.  */
      bzero (current_screen->used + from,
	     amount * sizeof current_screen->used[0]);
      bzero (current_screen->highlight + from,
	     amount * sizeof current_screen->highlight[0]);
      for (i = from; i < from + amount; i++)
	{
	  current_screen->glyphs[i][0] = '\0';
	  current_screen->enable[i] = 1;
	}

      safe_bcopy (current_screen->bufp + from,
		  current_screen->bufp + from + amount,
		  (end - from) * sizeof current_screen->bufp[0]);

#ifdef HAVE_X_WINDOWS
      if (SCREEN_IS_X (screen))
	{
	  safe_bcopy (current_screen->nruns + from,
		      current_screen->nruns + from + amount,
		      (end - from) * sizeof current_screen->nruns[0]);

	  safe_bcopy (current_screen->face_list + from,
		      current_screen->face_list + from + amount,
		      (end - from) * sizeof current_screen->face_list[0]);

	  safe_bcopy (current_screen->top_left_x + from,
		      current_screen->top_left_x + from + amount,
		      (end - from) * sizeof current_screen->top_left_x[0]);

	  safe_bcopy (current_screen->top_left_y + from,
		      current_screen->top_left_y + from + amount,
		      (end - from) * sizeof current_screen->top_left_y[0]);

	  safe_bcopy (current_screen->pix_width + from,
		      current_screen->pix_width + from + amount,
		      (end - from) * sizeof current_screen->pix_width[0]);

	  safe_bcopy (current_screen->pix_height + from,
		      current_screen->pix_height + from + amount,
		      (end - from) * sizeof current_screen->pix_height[0]);
	}
#endif				/* HAVE_X_WINDOWS */

      update_end (screen);
    }
  if (amount < 0)
    {
      update_begin (screen);
      set_terminal_window (end);
      ins_del_lines (from + amount, amount);
      if (!scroll_region_ok)
	ins_del_lines (end + amount, -amount);
      set_terminal_window (0);

      rotate_vector (current_screen->glyphs + from + amount,
		     sizeof (GLYPH *) * (end - from - amount),
		     amount * sizeof (GLYPH *));

      safe_bcopy (current_screen->used + from,
		  current_screen->used + from + amount,
		  (end - from) * sizeof current_screen->used[0]);

      safe_bcopy (current_screen->highlight + from,
		  current_screen->highlight + from + amount,
		  (end - from) * sizeof current_screen->highlight[0]);

      safe_bcopy (current_screen->enable + from,
		  current_screen->enable + from + amount,
		  (end - from) * sizeof current_screen->enable[0]);

      /* Mark the lines made empty by scrolling as enabled, empty and
	 normal video.  */
      bzero (current_screen->used + end + amount,
	     - amount * sizeof current_screen->used[0]);
      bzero (current_screen->highlight + end + amount,
	     - amount * sizeof current_screen->highlight[0]);
      for (i = end + amount; i < end; i++)
	{
	  current_screen->glyphs[i][0] = '\0';
	  current_screen->enable[i] = 1;
	}

      safe_bcopy (current_screen->bufp + from,
		  current_screen->bufp + from + amount,
		  (end - from) * sizeof current_screen->bufp[0]);

#ifdef HAVE_X_WINDOWS
      if (SCREEN_IS_X (screen))
	{
	  safe_bcopy (current_screen->nruns + from,
		      current_screen->nruns + from + amount,
		      (end - from) * sizeof current_screen->nruns[0]);

	  safe_bcopy (current_screen->face_list + from,
		      current_screen->face_list + from + amount,
		      (end - from) * sizeof current_screen->face_list[0]);

	  safe_bcopy (current_screen->top_left_x + from,
		      current_screen->top_left_x + from + amount,
		      (end - from) * sizeof current_screen->top_left_x[0]);

	  safe_bcopy (current_screen->top_left_y + from,
		      current_screen->top_left_y + from + amount,
		      (end - from) * sizeof current_screen->top_left_y[0]);

	  safe_bcopy (current_screen->pix_width + from,
		      current_screen->pix_width + from + amount,
		      (end - from) * sizeof current_screen->pix_width[0]);

	  safe_bcopy (current_screen->pix_height + from,
		      current_screen->pix_height + from + amount,
		      (end - from) * sizeof current_screen->pix_height[0]);
	}
#endif				/* HAVE_X_WINDOWS */

      update_end (screen);
    }
  return 1;
}

/* After updating a window W that isn't the full screen wide,
   copy all the columns that W does not occupy
   into the SCREEN_DESIRED_GLYPHS (screen) from the SCREEN_PHYS_GLYPHS (screen)
   so that update_screen will not change those columns.  */

preserve_other_columns (w)
     struct window *w;
{
  register int vpos;
  register struct screen_glyphs *current_screen, *desired_screen;
  register SCREEN_PTR screen = XSCREEN (w->screen);
  int start = XFASTINT (w->left);
  int end = XFASTINT (w->left) + XFASTINT (w->width);
  int bot = XFASTINT (w->top) + XFASTINT (w->height);

  current_screen = SCREEN_CURRENT_GLYPHS (screen);
  desired_screen = SCREEN_DESIRED_GLYPHS (screen);

  for (vpos = XFASTINT (w->top); vpos < bot; vpos++)
    {
      if (current_screen->enable[vpos] && desired_screen->enable[vpos])
	{
	  if (start > 0)
	    {
	      int len;

	      bcopy (current_screen->glyphs[vpos],
		     desired_screen->glyphs[vpos], start);
	      len = min (start, current_screen->used[vpos]);
	      if (desired_screen->used[vpos] < len)
		desired_screen->used[vpos] = len;
	    }
	  if (current_screen->used[vpos] > end
	      && desired_screen->used[vpos] < current_screen->used[vpos])
	    {
	      while (desired_screen->used[vpos] < end)
		desired_screen->glyphs[vpos][desired_screen->used[vpos]++]
		  = SPACEGLYPH;
	      bcopy (current_screen->glyphs[vpos] + end,
		     desired_screen->glyphs[vpos] + end,
		     current_screen->used[vpos] - end);
	      desired_screen->used[vpos] = current_screen->used[vpos];
	    }
	}
    }
}

#if 0

/* If window w does not need to be updated and isn't the full screen wide,
 copy all the columns that w does occupy
 into the SCREEN_DESIRED_LINES (screen) from the SCREEN_PHYS_LINES (screen)
 so that update_screen will not change those columns.

 Have not been able to figure out how to use this correctly.  */

preserve_my_columns (w)
     struct window *w;
{
  register int vpos, fin;
  register struct screen_glyphs *l1, *l2;
  register SCREEN_PTR screen = XSCREEN (w->screen);
  int start = XFASTINT (w->left);
  int end = XFASTINT (w->left) + XFASTINT (w->width);
  int bot = XFASTINT (w->top) + XFASTINT (w->height);

  for (vpos = XFASTINT (w->top); vpos < bot; vpos++)
    {
      if ((l1 = SCREEN_DESIRED_GLYPHS (screen)->glyphs[vpos + 1])
	  && (l2 = SCREEN_PHYS_GLYPHS (screen)->glyphs[vpos + 1]))
	{
	  if (l2->length > start && l1->length < l2->length)
	    {
	      fin = l2->length;
	      if (fin > end) fin = end;
	      while (l1->length < start)
		l1->body[l1->length++] = ' ';
	      bcopy (l2->body + start, l1->body + start, fin - start);
	      l1->length = fin;
	    }
	}
    }
}

#endif

/* On discovering that the redisplay for a window was no good,
   cancel the columns of that window, so that when the window is
   displayed over again get_display_line will not complain.  */

cancel_my_columns (w)
     struct window *w;
{
  register int vpos;
  register SCREEN_PTR screen = XSCREEN (w->screen);
  register struct screen_glyphs *desired_glyphs = screen->desired_glyphs;
  register int start = XFASTINT (w->left);
  register int bot = XFASTINT (w->top) + XFASTINT (w->height);

  for (vpos = XFASTINT (w->top); vpos < bot; vpos++)
    if (desired_glyphs->enable[vpos]
	&& desired_glyphs->used[vpos] >= start)
      desired_glyphs->used[vpos] = start;
}

/* These functions try to perform directly and immediately on the screen
   the necessary output for one change in the buffer.
   They may return 0 meaning nothing was done if anything is difficult,
   or 1 meaning the output was performed properly.
   They assume that the screen was up to date before the buffer
   change being displayed.  THey make various other assumptions too;
   see command_loop_1 where these are called.  */

int
direct_output_for_insert (g)
     int g;
{
  register SCREEN_PTR screen = selected_screen;
  register struct screen_glyphs *current_screen
    = SCREEN_CURRENT_GLYPHS (screen);

#ifndef COMPILER_REGISTER_BUG
  register
#endif /* COMPILER_REGISTER_BUG */
    struct window *w = XWINDOW (selected_window);
#ifndef COMPILER_REGISTER_BUG
  register
#endif /* COMPILER_REGISTER_BUG */
    int hpos = SCREEN_CURSOR_X (screen);
#ifndef COMPILER_REGISTER_BUG
  register
#endif /* COMPILER_REGISTER_BUG */
    int vpos = SCREEN_CURSOR_Y (screen);

  /* Give up if about to continue line */
  if (hpos - XFASTINT (w->left) + 1 + 1 >= XFASTINT (w->width)

  /* Avoid losing if cursor is in invisible text off left margin */
      || (XINT (w->hscroll) && hpos == XFASTINT (w->left))
    
  /* Give up if cursor outside window (in minibuf, probably) */
      || SCREEN_CURSOR_Y (screen) < XFASTINT (w->top)
      || SCREEN_CURSOR_Y (screen) >= XFASTINT (w->top) + XFASTINT (w->height)

  /* Give up if cursor not really at SCREEN_CURSOR_X, SCREEN_CURSOR_Y */
      || !display_completed

  /* Give up if buffer appears in two places.  */
      || buffer_shared > 1

  /* Give up if w is minibuffer and a message is being displayed there */
      || (MINI_WINDOW_P (w) && echo_area_glyphs))
    return 0;

  current_screen->glyphs[vpos][hpos] = g;
  unchanged_modified = MODIFF;
  beg_unchanged = GPT - BEG;
  XFASTINT (w->last_point) = point;
  XFASTINT (w->last_point_x) = hpos;
  XFASTINT (w->last_modified) = MODIFF;

  reassert_line_highlight (0, vpos);
  write_glyphs (&current_screen->glyphs[vpos][hpos], 1);
  fflush (stdout);
  ++SCREEN_CURSOR_X (screen);
  if (hpos == current_screen->used[vpos])
    {
      current_screen->used[vpos] = hpos + 1;
      current_screen->glyphs[vpos][hpos + 1] = 0;
    }

  return 1;
}

int
direct_output_forward_char (n)
     int n;
{
  register SCREEN_PTR screen = selected_screen;
  register struct window *w = XWINDOW (selected_window);

Jim Blandy's avatar
Jim Blandy committed
924 925 926 927 928 929 930 931 932
  /* Avoid losing if cursor is in invisible text off left margin
     or about to go off either side of window.  */
  if ((SCREEN_CURSOR_X (screen) == XFASTINT (w->left)
       && (XINT (w->hscroll) || n < 0))
      || (n > 0
	  && (SCREEN_CURSOR_X (screen) + 1
	      >= (XFASTINT (w->left) + XFASTINT (w->width)
		  - (XFASTINT (w->width) < SCREEN_WIDTH (screen))
		  - 1))))
Jim Blandy's avatar
Jim Blandy committed
933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978
    return 0;

  SCREEN_CURSOR_X (screen) += n;
  XFASTINT (w->last_point_x) = SCREEN_CURSOR_X (screen);
  XFASTINT (w->last_point) = point;
  cursor_to (SCREEN_CURSOR_Y (screen), SCREEN_CURSOR_X (screen));
  fflush (stdout);
  return 1;
}

static void update_line ();

/* Update screen S based on the data in SCREEN_DESIRED_GLYPHS.
   Value is nonzero if redisplay stopped due to pending input.
   FORCE nonzero means do not stop for pending input.  */

int
update_screen (s, force, inhibit_hairy_id)
     SCREEN_PTR s;
     int force;
     int inhibit_hairy_id;
{
  register struct screen_glyphs *current_screen = SCREEN_CURRENT_GLYPHS (s);
  register struct screen_glyphs *desired_screen = SCREEN_DESIRED_GLYPHS (s);
  register int i;
  int pause;
  int preempt_count = baud_rate / 2400 + 1;
  extern input_pending;
#ifdef HAVE_X_WINDOWS
  register int downto, leftmost;
#endif

  if (SCREEN_HEIGHT (s) == 0) abort (); /* Some bug zeros some core */

  detect_input_pending ();
  if (input_pending && !force)
    {
      pause = 1;
      goto do_pause;
    }

  update_begin (s);

  if (!line_ins_del_ok)
    inhibit_hairy_id = 1;

Jim Blandy's avatar
Jim Blandy committed
979 980
  /* See if any of the desired lines are enabled; don't compute for
     i/d line if just want cursor motion. */
Jim Blandy's avatar
Jim Blandy committed
981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027
  for (i = 0; i < SCREEN_HEIGHT (s); i++)
    if (desired_screen->enable[i])
      break;

  /* Try doing i/d line, if not yet inhibited.  */
  if (!inhibit_hairy_id && i < SCREEN_HEIGHT (s))
    force |= scrolling (s);

  /* Update the individual lines as needed.  Do bottom line first.  */

  if (desired_screen->enable[SCREEN_HEIGHT (s) - 1])
    update_line (s, SCREEN_HEIGHT (s) - 1);

#ifdef HAVE_X_WINDOWS
  if (SCREEN_IS_X (s))
    {
      leftmost = downto = s->display.x->internal_border_width;
      if (desired_screen->enable[0])
	{
	  current_screen->top_left_x[SCREEN_HEIGHT (s) - 1] = leftmost;
	  current_screen->top_left_y[SCREEN_HEIGHT (s) - 1]
	    = PIXEL_HEIGHT (s) - s->display.x->internal_border_width
	      - LINE_HEIGHT(s, SCREEN_HEIGHT (s) - 1);
	  current_screen->top_left_x[0] = leftmost;
	  current_screen->top_left_y[0] = downto;
	}
    }
#endif /* HAVE_X_WINDOWS */

  /* Now update the rest of the lines. */
  for (i = 0; i < SCREEN_HEIGHT (s) - 1 && (force || !input_pending); i++)
    {
      if (desired_screen->enable[i])
	{
	  if (SCREEN_IS_TERMCAP (s))
	    {
	      /* Flush out every so many lines.
		 Also flush out if likely to have more than 1k buffered
		 otherwise.   I'm told that some telnet connections get
		 really screwed by more than 1k output at once.  */
	      int outq = PENDING_OUTPUT_COUNT (stdout);
	      if (outq > 900
		  || (outq > 20 && ((i - 1) % preempt_count == 0)))
		{
		  fflush (stdout);
		  if (preempt_count == 1)
		    {
Jim Blandy's avatar
Jim Blandy committed
1028 1029
#ifdef EMACS_OUTQSIZE
		      if (EMACS_OUTQSIZE (0, &outq) < 0)
Jim Blandy's avatar
Jim Blandy committed
1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059
			/* Probably not a tty.  Ignore the error and reset
			 * the outq count. */
			outq = PENDING_OUTPUT_COUNT (stdout);
#endif
		      outq *= 10;
		      sleep (outq / baud_rate);
		    }
		}
	      if ((i - 1) % preempt_count == 0)
		detect_input_pending ();
	    }

	  update_line (s, i);
#ifdef HAVE_X_WINDOWS
	  if (SCREEN_IS_X (s))
	    {
	      current_screen->top_left_y[i] = downto;
	      current_screen->top_left_x[i] = leftmost;
	    }
#endif /* HAVE_X_WINDOWS */
	}

      if (SCREEN_IS_X (s))
	downto += LINE_HEIGHT(s, i);
    }
  pause = (i < SCREEN_HEIGHT (s) - 1) ? i : 0;

  /* Now just clean up termcap drivers and set cursor, etc.  */
  if (!pause)
    {
Jim Blandy's avatar
Jim Blandy committed
1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072
      if (cursor_in_echo_area)
	{
	  if (s == selected_screen
	      && cursor_in_echo_area < 0)
	    cursor_to (SCREEN_HEIGHT (s) - 1, 0);
	  else if (s == selected_screen
		   && ! current_screen->enable[SCREEN_HEIGHT (s) - 1])
	    cursor_to (SCREEN_HEIGHT (s) - 1, 0);
	  else
	    cursor_to (SCREEN_HEIGHT (s) - 1,
		       min (SCREEN_WIDTH (s) - 1,
			    current_screen->used[SCREEN_HEIGHT (s) - 1]));
	}
Jim Blandy's avatar
Jim Blandy committed
1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195
      else
	cursor_to (SCREEN_CURSOR_Y (s), max (min (SCREEN_CURSOR_X (s),
						  SCREEN_WIDTH (s) - 1), 0));
    }

  update_end (s);

  if (termscript)
    fflush (termscript);
  fflush (stdout);

  /* Here if output is preempted because input is detected.  */
 do_pause:

  if (SCREEN_HEIGHT (s) == 0) abort (); /* Some bug zeros some core */
  display_completed = !pause;

  bzero (desired_screen->enable, SCREEN_HEIGHT (s));
  return pause;
}

/* Called when about to quit, to check for doing so
   at an improper time.  */

void
quit_error_check ()
{
  if (SCREEN_DESIRED_GLYPHS (selected_screen) == 0)
    return;
  if (SCREEN_DESIRED_GLYPHS (selected_screen)->enable[0])
    abort ();
  if (SCREEN_DESIRED_GLYPHS (selected_screen)->enable[SCREEN_HEIGHT (selected_screen) - 1])
    abort ();
}

/* Decide what insert/delete line to do, and do it */

extern void scrolling_1 ();

scrolling (screen)
     SCREEN_PTR screen;
{
  int unchanged_at_top, unchanged_at_bottom;
  int window_size;
  int changed_lines;
  int *old_hash = (int *) alloca (SCREEN_HEIGHT (screen) * sizeof (int));
  int *new_hash = (int *) alloca (SCREEN_HEIGHT (screen) * sizeof (int));
  int *draw_cost = (int *) alloca (SCREEN_HEIGHT (screen) * sizeof (int));
  register int i;
  int free_at_end_vpos = SCREEN_HEIGHT (screen);
  register struct screen_glyphs *current_screen = SCREEN_CURRENT_GLYPHS (screen);
  register struct screen_glyphs *desired_screen = SCREEN_DESIRED_GLYPHS (screen);

  /* Compute hash codes of all the lines.
     Also calculate number of changed lines,
     number of unchanged lines at the beginning,
     and number of unchanged lines at the end.  */

  changed_lines = 0;
  unchanged_at_top = 0;
  unchanged_at_bottom = SCREEN_HEIGHT (screen);
  for (i = 0; i < SCREEN_HEIGHT (screen); i++)
    {
      /* Give up on this scrolling if some old lines are not enabled.  */
      if (!current_screen->enable[i])
	return 0;
      old_hash[i] = line_hash_code (current_screen, i);
      if (! desired_screen->enable[i])
	new_hash[i] = old_hash[i];
      else
	new_hash[i] = line_hash_code (desired_screen, i);

      if (old_hash[i] != new_hash[i])
	{
	  changed_lines++;
	  unchanged_at_bottom = SCREEN_HEIGHT (screen) - i - 1;
	}
      else if (i == unchanged_at_top)
	unchanged_at_top++;
      draw_cost[i] = line_draw_cost (desired_screen, i);
    }

  /* If changed lines are few, don't allow preemption, don't scroll.  */
  if (changed_lines < baud_rate / 2400
      || unchanged_at_bottom == SCREEN_HEIGHT (screen))
    return 1;

  window_size = (SCREEN_HEIGHT (screen) - unchanged_at_top
		 - unchanged_at_bottom);

  if (scroll_region_ok)
    free_at_end_vpos -= unchanged_at_bottom;
  else if (memory_below_screen)
    free_at_end_vpos = -1;

  /* If large window, fast terminal and few lines in common between
     current screen and desired screen, don't bother with i/d calc. */
  if (window_size >= 18 && baud_rate > 2400
      && (window_size >=
	  10 * scrolling_max_lines_saved (unchanged_at_top,
					  SCREEN_HEIGHT (screen) - unchanged_at_bottom,
					  old_hash, new_hash, draw_cost)))
    return 0;

  scrolling_1 (screen, window_size, unchanged_at_top, unchanged_at_bottom,
	       draw_cost + unchanged_at_top - 1,
	       old_hash + unchanged_at_top - 1,
	       new_hash + unchanged_at_top - 1,
	       free_at_end_vpos - unchanged_at_top);

  return 0;
}

/* Return the offset in its buffer of the character at location col, line
   in the given window.  */
int
buffer_posn_from_coords (window, col, line)
     struct window *window;
     int col, line;
{
  int window_left = XFASTINT (window->left);

  /* The actual width of the window is window->width less one for the
Jim Blandy's avatar
Jim Blandy committed
1196 1197
     DISP_CONTINUE_GLYPH, and less one if it's not the rightmost
     window.  */
Jim Blandy's avatar
Jim Blandy committed
1198 1199 1200 1201
  int window_width = (XFASTINT (window->width) - 1
		      - (XFASTINT (window->width) + window_left
			 != SCREEN_WIDTH (XSCREEN (window->screen))));

Jim Blandy's avatar
Jim Blandy committed
1202
  int startp = marker_position (window->start);
Jim Blandy's avatar
Jim Blandy committed
1203 1204 1205 1206

  /* Since compute_motion will only operate on the current buffer,
     we need to save the old one and restore it when we're done.  */
  struct buffer *old_current_buffer = current_buffer;
Jim Blandy's avatar
Jim Blandy committed
1207
  struct position *posn;
Jim Blandy's avatar
Jim Blandy committed
1208 1209 1210

  current_buffer = XBUFFER (window->buffer);

Jim Blandy's avatar
Jim Blandy committed
1211 1212 1213 1214 1215 1216 1217 1218 1219
  /* It would be nice if we could use SCREEN_CURRENT_GLYPHS (XSCREEN
     (window->screen))->bufp to avoid scanning from the very top of
     the window, but it isn't maintained correctly, and I'm not even
     sure I will keep it.  */
  posn = compute_motion (startp, 0,
			 (window == XWINDOW (minibuf_window) && startp == 1
			  ? minibuf_prompt_width : 0),
			 ZV, line, col - window_left,
			 window_width, XINT (window->hscroll), 0);
Jim Blandy's avatar
Jim Blandy committed
1220 1221 1222

  current_buffer = old_current_buffer;

Jim Blandy's avatar
Jim Blandy committed
1223 1224 1225 1226 1227 1228 1229 1230
  /* compute_motion considers screen points past the end of a line
     to be *after* the newline, i.e. at the start of the next line.
     This is reasonable, but not really what we want.  So if the
     result is on a line below LINE, back it up one character.  */
  if (posn->vpos > line)
    return posn->bufpos - 1;
  else
    return posn->bufpos;
Jim Blandy's avatar
Jim Blandy committed
1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
}

static int
count_blanks (r)
     register GLYPH *r;
{
  register GLYPH *p = r;
  while (*r++ == SPACEGLYPH);
  return r - p - 1;
}

static int
count_match (str1, str2)
     GLYPH *str1, *str2;
{
  register GLYPH *p1 = str1;
  register GLYPH *p2 = str2;
  while (*p1++ == *p2++);
  return p1 - str1 - 1;
}

/* Char insertion/deletion cost vector, from term.c */
extern int *char_ins_del_vector;

#define char_ins_del_cost(s) (&char_ins_del_vector[SCREEN_HEIGHT((s))])

static void
update_line (screen, vpos)
     register SCREEN_PTR screen;
     int vpos;
{
  register GLYPH *obody, *nbody, *op1, *op2, *np1, *temp;
  int tem;
  int osp, nsp, begmatch, endmatch, olen, nlen;
  int save;
  register struct screen_glyphs *current_screen
    = SCREEN_CURRENT_GLYPHS (screen);
  register struct screen_glyphs *desired_screen
    = SCREEN_DESIRED_GLYPHS (screen);

  if (desired_screen->highlight[vpos]
      != (current_screen->enable[vpos] && current_screen->highlight[vpos]))
    {
      change_line_highlight (desired_screen->highlight[vpos], vpos,
			     (current_screen->enable[vpos] ?
			      current_screen->used[vpos] : 0));
      current_screen->enable[vpos] = 0;
    }
  else
    reassert_line_highlight (desired_screen->highlight[vpos], vpos);

  if (! current_screen->enable[vpos])
    {
      olen = 0;
    }
  else
    {
      obody = current_screen->glyphs[vpos];
      olen = current_screen->used[vpos];
      if (! current_screen->highlight[vpos])
	{
	  if (!must_write_spaces)
	    while (obody[olen - 1] == SPACEGLYPH && olen > 0)
	      olen--;
	}
      else
	{
	  /* For an inverse-video line, remember we gave it
	     spaces all the way to the screen edge
	     so that the reverse video extends all the way across.  */

	  while (olen < SCREEN_WIDTH (screen) - 1)
	    obody[olen++] = SPACEGLYPH;
	}
    }

  /* One way or another, this will enable the line being updated.  */
  current_screen->enable[vpos] = 1;
  current_screen->used[vpos] = desired_screen->used[vpos];
  current_screen->highlight[vpos] = desired_screen->highlight[vpos];
  current_screen->bufp[vpos] = desired_screen->bufp[vpos];

#ifdef HAVE_X_WINDOWS
  if (SCREEN_IS_X (screen))
    {
      current_screen->pix_width[vpos]
	= current_screen->used[vpos]
	  * FONT_WIDTH (screen->display.x->font);
      current_screen->pix_height[vpos]
	= FONT_HEIGHT (screen->display.x->font);
    }
#endif /* HAVE_X_WINDOWS */

  if (!desired_screen->enable[vpos])
    {
      nlen = 0;
      goto just_erase;
    }

  nbody = desired_screen->glyphs[vpos];
  nlen = desired_screen->used[vpos];

  /* Pretend trailing spaces are not there at all,
     unless for one reason or another we must write all spaces.  */
  if (! desired_screen->highlight[vpos])
    {
      if (!must_write_spaces)
	/* We know that the previous character byte contains 0.  */
	while (nbody[nlen - 1] == SPACEGLYPH)
	  nlen--;
    }
  else
    {
      /* For an inverse-video line, give it extra trailing spaces
	 all the way to the screen edge
	 so that the reverse video extends all the way across.  */

      while (nlen < SCREEN_WIDTH (screen) - 1)
	nbody[nlen++] = SPACEGLYPH;
    }

  /* If there's no i/d char, quickly do the best we can without it.  */
  if (!char_ins_del_ok)
    {
      int i,j;

      for (i = 0; i < nlen; i++)
	{
	  if (i >= olen || nbody[i] != obody[i])    /* A non-matching char. */
	    {
	      cursor_to (vpos, i);
	      for (j = 1; (i + j < nlen &&
			   (i + j >= olen || nbody[i+j] != obody[i+j]));
		   j++);

	      /* Output this run of non-matching chars.  */ 
	      write_glyphs (nbody + i, j);
	      i += j - 1;

	      /* Now find the next non-match.  */
	    }
	}

      /* Clear the rest of the line, or the non-clear part of it.  */
      if (olen > nlen)
	{
	  cursor_to (vpos, nlen);
	  clear_end_of_line (olen);
	}

      /* Exchange contents between current_screen and new_screen.  */
      temp = desired_screen->glyphs[vpos];
      desired_screen->glyphs[vpos] = current_screen->glyphs[vpos];
      current_screen->glyphs[vpos] = temp;

      return;
    }

  if (!olen)
    {
      nsp = (must_write_spaces || desired_screen->highlight[vpos])
	      ? 0 : count_blanks (nbody);
      if (nlen > nsp)
	{
	  cursor_to (vpos, nsp);
	  write_glyphs (nbody + nsp, nlen - nsp);
	}

      /* Exchange contents between current_screen and new_screen.  */
      temp = desired_screen->glyphs[vpos];
      desired_screen->glyphs[vpos] = current_screen->glyphs[vpos];
      current_screen->glyphs[vpos] = temp;

      return;
    }

  obody[olen] = 1;
  save = nbody[nlen];
  nbody[nlen] = 0;

  /* Compute number of leading blanks in old and new contents.  */
  osp = count_blanks (obody);
  if (!desired_screen->highlight[vpos])
    nsp = count_blanks (nbody);
  else
    nsp = 0;

  /* Compute number of matching chars starting with first nonblank.  */
  begmatch = count_match (obody + osp, nbody + nsp);

  /* Spaces in new match implicit space past the end of old.  */
  /* A bug causing this to be a no-op was fixed in 18.29.  */
  if (!must_write_spaces && osp + begmatch == olen)
    {
      np1 = nbody + nsp;
      while (np1[begmatch] == SPACEGLYPH)
	begmatch++;
    }

  /* Avoid doing insert/delete char
     just cause number of leading spaces differs
     when the following text does not match. */
  if (begmatch == 0 && osp != nsp)
    osp = nsp = min (osp, nsp);

  /* Find matching characters at end of line */
  op1 = obody + olen;
  np1 = nbody + nlen;
  op2 = op1 + begmatch - min (olen - osp, nlen - nsp);
  while (op1 > op2 && op1[-1] == np1[-1])
    {
      op1--;
      np1--;
    }
  endmatch = obody + olen - op1;

  /* Put correct value back in nbody[nlen].
     This is important because direct_output_for_insert
     can write into the line at a later point.
     If this screws up the zero at the end of the line, re-establish it.  */
  nbody[nlen] = save;
  obody[olen] = 0;

  /* tem gets the distance to insert or delete.
     endmatch is how many characters we save by doing so.
     Is it worth it?  */

  tem = (nlen - nsp) - (olen - osp);
  if (endmatch && tem
      && (!char_ins_del_ok || endmatch <= char_ins_del_cost (screen)[tem]))
    endmatch = 0;

  /* nsp - osp is the distance to insert or delete.
     If that is nonzero, begmatch is known to be nonzero also.
     begmatch + endmatch is how much we save by doing the ins/del.
     Is it worth it?  */

  if (nsp != osp
      && (!char_ins_del_ok
	  || begmatch + endmatch <= char_ins_del_cost (screen)[nsp - osp]))
    {
      begmatch = 0;
      endmatch = 0;
      osp = nsp = min (osp, nsp);
    }

  /* Now go through the line, inserting, writing and
     deleting as appropriate.  */

  if (osp > nsp)
    {
      cursor_to (vpos, nsp);
      delete_glyphs (osp - nsp);
    }
  else if (nsp > osp)
    {
      /* If going to delete chars later in line
	 and insert earlier in the line,
	 must delete first to avoid losing data in the insert */
      if (endmatch && nlen < olen + nsp - osp)
	{
	  cursor_to (vpos, nlen - endmatch + osp - nsp);
	  delete_glyphs (olen + nsp - osp - nlen);
	  olen = nlen - (nsp - osp);
	}
      cursor_to (vpos, osp);
      insert_glyphs ((char *)0, nsp - osp);
    }
  olen += nsp - osp;

  tem = nsp + begmatch + endmatch;
  if (nlen != tem || olen != tem)
    {
      cursor_to (vpos, nsp + begmatch);
      if (!endmatch || nlen == olen)
	{
	  /* If new text being written reaches right margin,
	     there is no need to do clear-to-eol at the end.
	     (and it would not be safe, since cursor is not
	     going to be "at the margin" after the text is done) */
	  if (nlen == SCREEN_WIDTH (screen))
	    olen = 0;
	  write_glyphs (nbody + nsp + begmatch, nlen - tem);

#ifdef obsolete

/* the following code loses disastrously if tem == nlen.
   Rather than trying to fix that case, I am trying the simpler
   solution found above.  */

	  /* If the text reaches to the right margin,
	     it will lose one way or another (depending on AutoWrap)
	     to clear to end of line after outputting all the text.
	     So pause with one character to go and clear the line then.  */
	  if (nlen == SCREEN_WIDTH (screen) && fast_clear_end_of_line && olen > nlen)
	    {
	      /* endmatch must be zero, and tem must equal nsp + begmatch */
	      write_glyphs (nbody + tem, nlen - tem - 1);
	      clear_end_of_line (olen);
	      olen = 0;		/* Don't let it be cleared again later */
	      write_glyphs (nbody + nlen - 1, 1);
	    }
	  else
	    write_glyphs (nbody + nsp + begmatch, nlen - tem);
#endif	/* OBSOLETE */

	}
      else if (nlen > olen)
	{
	  write_glyphs (nbody + nsp + begmatch, olen - tem);
	  insert_glyphs (nbody + nsp + begmatch + olen - tem, nlen - olen);
	  olen = nlen;
	}
      else if (olen > nlen)
	{
	  write_glyphs (nbody + nsp + begmatch, nlen - tem);
	  delete_glyphs (olen - nlen);
	  olen = nlen;
	}
    }

 just_erase:
  /* If any unerased characters remain after the new line, erase them.  */
  if (olen > nlen)
    {
      cursor_to (vpos, nlen);
      clear_end_of_line (olen);
    }

  /* Exchange contents between current_screen and new_screen.  */
  temp = desired_screen->glyphs[vpos];
  desired_screen->glyphs[vpos] = current_screen->glyphs[vpos];
  current_screen->glyphs[vpos] = temp;
}

DEFUN ("open-termscript", Fopen_termscript, Sopen_termscript,
  1, 1, "FOpen termscript file: ",
  "Start writing all terminal output to FILE as well as the terminal.\n\
FILE = nil means just close any termscript file currently open.")
  (file)
     Lisp_Object file;
{
  if (termscript != 0) fclose (termscript);
  termscript = 0;

Jim Blandy's avatar
Jim Blandy committed
1576
  if (! NILP (file))
Jim Blandy's avatar
Jim Blandy committed
1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587
    {
      file = Fexpand_file_name (file, Qnil);
      termscript = fopen (XSTRING (file)->data, "w");
      if (termscript == 0)
	report_file_error ("Opening termscript", Fcons (file, Qnil));
    }
  return Qnil;
}


#ifdef SIGWINCH
Jim Blandy's avatar
Jim Blandy committed
1588
SIGTYPE
Jim Blandy's avatar
Jim Blandy committed
1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610
window_change_signal ()
{
  int width, height;
  extern int errno;
  int old_errno = errno;

  get_screen_size (&width, &height);

  /* The screen size change obviously applies to a termcap-controlled
     screen.  Find such a screen in the list, and assume it's the only
     one (since the redisplay code always writes to stdout, not a
     FILE * specified in the screen structure).  Record the new size,
     but don't reallocate the data structures now.  Let that be done
     later outside of the signal handler.  */

  {
    Lisp_Object tail;

    for (tail = Vscreen_list; CONSP (tail); tail = XCONS (tail)->cdr)
      {
	SCREEN_PTR s = XSCREEN (XCONS (tail)->car);
	
Jim Blandy's avatar
Jim Blandy committed
1611
	if (SCREEN_IS_TERMCAP (s))
Jim Blandy's avatar
Jim Blandy committed
1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
	  {
	    ++in_display;
	    change_screen_size (s, height, width, 0);
	    --in_display;
	    break;
	  }
      }
  }

  signal (SIGWINCH, window_change_signal);
  errno = old_errno;
}
#endif /* SIGWINCH */


/* Do any change in screen size that was requested by a signal.  */

do_pending_window_change ()
{
  /* If window_change_signal should have run before, run it now.  */
  while (delayed_size_change)
    {
      Lisp_Object tail;

      delayed_size_change = 0;

      for (tail = Vscreen_list; CONSP (tail); tail = XCONS (tail)->cdr)
	{
	  SCREEN_PTR s = XSCREEN (XCONS (tail)->car);
	  int height = SCREEN_NEW_HEIGHT (s);
	  int width = SCREEN_NEW_WIDTH (s);
	    
	  SCREEN_NEW_HEIGHT (s) = 0;
	  SCREEN_NEW_WIDTH (s) = 0;

	  if (height != 0)
	    change_screen_size (s, height, width, 0);
	}
    }
}


/* Change the screen height and/or width.  Values may be given as zero to
   indicate no change is to take place. */

change_screen_size (screen, newlength, newwidth, pretend)
     register SCREEN_PTR screen;
     register int newlength, newwidth, pretend;
{
  /* If we can't deal with the change now, queue it for later.  */
  if (in_display)
    {
      SCREEN_NEW_HEIGHT (screen) = newlength;
      SCREEN_NEW_WIDTH (screen) = newwidth;
      delayed_size_change = 1;
      return;
    }

  /* This size-change overrides any pending one for this screen.  */
  SCREEN_NEW_HEIGHT (screen) = 0;
  SCREEN_NEW_WIDTH (screen) = 0;

  if ((newlength == 0 || newlength == SCREEN_HEIGHT (screen))
      && (newwidth == 0 || newwidth == SCREEN_WIDTH (screen)))
    return;

  if (newlength && newlength != SCREEN_HEIGHT (screen))
    {
Jim Blandy's avatar
Jim Blandy committed
1680 1681
      if (SCREEN_HAS_MINIBUF (screen)
	  && ! SCREEN_MINIBUF_ONLY_P (screen))
Jim Blandy's avatar
Jim Blandy committed
1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693
	{
	  /* Screen has both root and minibuffer.  */
	  set_window_height (SCREEN_ROOT_WINDOW (screen),
			     newlength - 1, 0);
	  XFASTINT (XWINDOW (SCREEN_MINIBUF_WINDOW (screen))->top)
	    = newlength - 1;
	  set_window_height (SCREEN_MINIBUF_WINDOW (screen), 1, 0);
	}
      else
	/* Screen has just one top-level window.  */
	set_window_height (SCREEN_ROOT_WINDOW (screen), newlength, 0);
	
Jim Blandy's avatar
Jim Blandy committed
1694
      if (SCREEN_IS_TERMCAP (screen) && !pretend)
Jim Blandy's avatar
Jim Blandy committed
1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709
	ScreenRows = newlength;

#if 0
      if (screen->output_method == output_termcap)
	{
	  screen_height = newlength;
	  if (!pretend)
	    ScreenRows = newlength;
	}
#endif
    }

  if (newwidth && newwidth != SCREEN_WIDTH (screen))
    {
      set_window_width (SCREEN_ROOT_WINDOW (screen), newwidth, 0);
Jim Blandy's avatar
Jim Blandy committed
1710
      if (SCREEN_HAS_MINIBUF (screen))
Jim Blandy's avatar
Jim Blandy committed
1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757
	set_window_width (SCREEN_MINIBUF_WINDOW (screen), newwidth, 0);
      SCREEN_WIDTH (screen) = newwidth;

      if (SCREEN_IS_TERMCAP (screen) && !pretend)
	ScreenCols = newwidth;
#if 0
      if (screen->output_method == output_termcap)
	{
	  screen_width = newwidth;
	  if (!pretend)
	    ScreenCols = newwidth;
	}
#endif
    }

  if (newlength)
    SCREEN_HEIGHT (screen) = newlength;

  remake_screen_glyphs (screen);
  calculate_costs (screen);
}

DEFUN ("send-string-to-terminal", Fsend_string_to_terminal,
  Ssend_string_to_terminal, 1, 1, 0,
  "Send STRING to the terminal without alteration.\n\
Control characters in STRING will have terminal-dependent effects.")
  (str)
     Lisp_Object str;
{
  CHECK_STRING (str, 0);
  fwrite (XSTRING (str)->data, 1, XSTRING (str)->size, stdout);
  fflush (stdout);
  if (termscript)
    {
      fwrite (XSTRING (str)->data, 1, XSTRING (str)->size, termscript);
      fflush (termscript);
    }
  return Qnil;
}

DEFUN ("ding", Fding, Sding, 0, 1, 0,
  "Beep, or flash the screen.\n\
Also, unless an argument is given,\n\
terminate any keyboard macro currently executing.")
  (arg)
  Lisp_Object arg;
{
Jim Blandy's avatar
Jim Blandy committed
1758
  if (!NILP (arg))
Jim Blandy's avatar
Jim Blandy committed
1759
    {
1760 1761 1762 1763
      if (noninteractive)
	putchar (07);
      else
	ring_bell ();
Jim Blandy's avatar
Jim Blandy committed
1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
      fflush (stdout);
    }
  else
    bitch_at_user ();

  return Qnil;
}

bitch_at_user ()
{
  if (noninteractive)
    putchar (07);
  else if (!INTERACTIVE)  /* Stop executing a keyboard macro. */
    error ("Keyboard macro terminated by a command ringing the bell");
  else
    ring_bell ();
  fflush (stdout);
}

DEFUN ("sleep-for", Fsleep_for, Ssleep_for, 1, 2, 0,
  "Pause, without updating display, for ARG seconds.\n\
Optional second arg non-nil means ARG is measured in milliseconds.\n\
\(Not all operating systems support milliseconds.)")
Jim Blandy's avatar
Jim Blandy committed
1787 1788
  (arg, millisec)
     Lisp_Object arg, millisec;
Jim Blandy's avatar
Jim Blandy committed
1789 1790 1791 1792
{
  int usec = 0;
  int sec;

Jim Blandy's avatar
Jim Blandy committed
1793 1794
  CHECK_NUMBER (arg, 0);
  sec = XINT (arg);
Jim Blandy's avatar
Jim Blandy committed
1795 1796 1797
  if (sec <= 0)
    return Qnil;

Jim Blandy's avatar
Jim Blandy committed
1798
  if (!NILP (millisec))
Jim Blandy's avatar
Jim Blandy committed
1799
    {
Jim Blandy's avatar
Jim Blandy committed
1800
#ifndef EMACS_HAS_USECS
1801
      error ("millisecond `sleep-for' not supported on %s", SYSTEM_TYPE);
Jim Blandy's avatar
Jim Blandy committed
1802 1803 1804 1805 1806 1807
#else
      usec = sec % 1000 * 1000;
      sec /= 1000;
#endif
    }

Jim Blandy's avatar
Jim Blandy committed
1808 1809 1810 1811 1812 1813
  {
    Lisp_Object zero;

    XFASTINT (zero) = 0;
    wait_reading_process_input (sec, usec, zero, 0);
  }
Jim Blandy's avatar
Jim Blandy committed
1814 1815

#if 0 /* No wait_reading_process_input */
Jim Blandy's avatar
Jim Blandy committed
1816 1817 1818 1819 1820 1821 1822 1823 1824 1825
  immediate_quit = 1;
  QUIT;

#ifdef VMS
  sys_sleep (sec);
#else /* not VMS */
/* The reason this is done this way 
    (rather than defined (H_S) && defined (H_T))
   is because the VMS preprocessor doesn't grok `defined' */
#ifdef HAVE_SELECT
Jim Blandy's avatar
Jim Blandy committed
1826 1827
  EMACS_GET_TIME (end_time);
  EMACS_SET_SECS_USECS (timeout, sec, usec);
Jim Blandy's avatar
Jim Blandy committed
1828
  EMACS_ADD_TIME (end_time, end_time, timeout);
Jim Blandy's avatar
Jim Blandy committed
1829
 
Jim Blandy's avatar
Jim Blandy committed
1830 1831
  while (1)
    {
Jim Blandy's avatar
Jim Blandy committed
1832 1833 1834 1835
      EMACS_GET_TIME (timeout);
      EMACS_SUB_TIME (timeout, end_time, timeout);
      if (EMACS_TIME_NEG_P (timeout)
	  || !select (1, 0, 0, 0, &timeout))
Jim Blandy's avatar
Jim Blandy committed
1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848
	break;
    }
#else /* not HAVE_SELECT */
  sleep (sec);
#endif /* HAVE_SELECT */
#endif /* not VMS */
  
  immediate_quit = 0;
#endif /* no subprocesses */

  return Qnil;
}

Jim Blandy's avatar
Jim Blandy committed
1849 1850 1851 1852 1853
/* This is just like wait_reading_process_input, except that
   it does the redisplay.

   It's also just like Fsit_for, except that it can be used for
   waiting for input as well.  */
Jim Blandy's avatar
Jim Blandy committed
1854

Jim Blandy's avatar
Jim Blandy committed
1855 1856 1857 1858 1859
Lisp_Object
sit_for (sec, usec, reading, display)
     int sec, usec, reading, display;
{
  Lisp_Object read_kbd;
Jim Blandy's avatar
Jim Blandy committed
1860 1861 1862 1863

  if (detect_input_pending ())
    return Qnil;

Jim Blandy's avatar
Jim Blandy committed
1864 1865
  if (display)
    redisplay_preserve_echo_area ();
Jim Blandy's avatar
Jim Blandy committed
1866

Jim Blandy's avatar
Jim Blandy committed
1867 1868 1869
  if (sec == 0 && usec == 0)
    return Qt;

Jim Blandy's avatar
Jim Blandy committed
1870 1871
#ifdef SIGIO
  gobble_input ();
Jim Blandy's avatar
Jim Blandy committed
1872 1873 1874 1875 1876
#endif

  XSET (read_kbd, Lisp_Int, reading ? -1 : 1);
  wait_reading_process_input (sec, usec, read_kbd, display);

Jim Blandy's avatar
Jim Blandy committed
1877 1878

#if 0 /* No wait_reading_process_input available.  */
Jim Blandy's avatar
Jim Blandy committed
1879 1880 1881 1882 1883
  immediate_quit = 1;
  QUIT;

  waitchannels = 1;
#ifdef VMS
Jim Blandy's avatar
Jim Blandy committed
1884
  input_wait_timeout (XINT (arg));
Jim Blandy's avatar
Jim Blandy committed
1885
#else				/* not VMS */
Jim Blandy's avatar
Jim Blandy committed
1886 1887 1888 1889 1890 1891
#ifndef HAVE_TIMEVAL
  timeout_sec = sec;
  select (1, &waitchannels, 0, 0, &timeout_sec);
#else /* HAVE_TIMEVAL */
  timeout.tv_sec = sec;  
  timeout.tv_usec = usec;
Jim Blandy's avatar
Jim Blandy committed
1892
  select (1, &waitchannels, 0, 0, &timeout);
Jim Blandy's avatar
Jim Blandy committed
1893
#endif /* HAVE_TIMEVAL */
Jim Blandy's avatar
Jim Blandy committed
1894 1895 1896
#endif /* not VMS */

  immediate_quit = 0;
Jim Blandy's avatar
Jim Blandy committed
1897
#endif 
Jim Blandy's avatar
Jim Blandy committed
1898 1899 1900 1901

  return detect_input_pending () ? Qnil : Qt;
}

Jim Blandy's avatar
Jim Blandy committed
1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912
DEFUN ("sit-for", Fsit_for, Ssit_for, 1, 3, 0,
  "Perform redisplay, then wait for ARG seconds or until input is available.\n\
Optional second arg non-nil means ARG counts in milliseconds.\n\
Optional third arg non-nil means don't r