1 /* Cursor motion subroutines for GNU Emacs.
2 Copyright (C) 1985, 1995 Free Software Foundation, Inc.
3 based primarily on public domain code written by Chris Torek
5 This file is part of GNU Emacs.
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 2, or (at your option)
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.
17 You should have received a copy of the GNU General Public License
18 along with GNU Emacs; see the file COPYING. If not, write to
19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA. */
29 #include "termhooks.h"
33 /* For now, don't try to include termcap.h. On some systems,
34 configure finds a non-standard termcap.h that the main build
37 #if defined HAVE_TERMCAP_H && 0
40 extern void tputs
P_ ((const char *, int, int (*)(int)));
41 extern char *tgoto
P_ ((const char *, int, int));
44 #define BIG 9999 /* 9999 good on VAXen. For 16 bit machines
49 int cost
; /* sums up costs */
60 /* The terminal to use for low-level output. */
61 struct tty_display_info
*current_tty
;
67 if (current_tty
->termscript
)
68 putc (c
& 0177, current_tty
->termscript
);
69 putc (c
& 0177, current_tty
->output
);
73 /* NEXT TWO ARE DONE WITH MACROS */
76 * Assume the cursor is at row row, column col. Normally used only after
77 * clearing the screen, when the cursor is at (0, 0), but what the heck,
78 * let's let the guy put it anywhere.
88 * Add n columns to the current cursor position.
96 * If cursor hit edge of screen, what happened?
97 * N.B.: DO NOT!! write past edge of screen. If you do, you
98 * deserve what you get. Furthermore, on terminals with
99 * autowrap (but not magicwrap), don't write in the last column
103 if (curX (tty
) == tty
->Wcm
->cm_cols
) {
105 * Well, if magicwrap, still there, past the edge of the
106 * screen (!). If autowrap, on the col 0 of the next line.
107 * Otherwise on last column.
110 if (tty
->Wcm
->cm_magicwrap
)
112 else if (tty
->Wcm
->cm_autowrap
) {
114 curY (tty
) ++; /* Beware end of screen! */
123 * Terminals with magicwrap (xn) don't all behave identically.
124 * The VT100 leaves the cursor in the last column but will wrap before
125 * printing the next character. I hear that the Concept terminal does
126 * the wrap immediately but ignores the next newline it sees. And some
127 * terminals just have buggy firmware, and think that the cursor is still
128 * in limbo if we use direct cursor addressing from the phantom column.
129 * The only guaranteed safe thing to do is to emit a CRLF immediately
130 * after we reach the last column; this takes us to a known state.
133 cmcheckmagic (struct tty_display_info
*tty
)
135 if (curX (tty
) == FrameCols (tty
))
137 if (!MagicWrap (tty
) || curY (tty
) >= FrameRows (tty
) - 1)
140 putc ('\r', tty
->termscript
);
141 putc ('\r', tty
->output
);
143 putc ('\n', tty
->termscript
);
144 putc ('\n', tty
->output
);
152 * (Re)Initialize the cost factors, given the output speed of the terminal
153 * in the variable ospeed. (Note: this holds B300, B9600, etc -- ie stuff
158 cmcostinit (struct tty_display_info
*tty
)
162 #define COST(x,e) (x ? (cost = 0, tputs (x, 1, e), cost) : BIG)
163 #define CMCOST(x,e) ((x == 0) ? BIG : (p = tgoto(x, 0, 0), COST(p ,e)))
165 tty
->Wcm
->cc_up
= COST (tty
->Wcm
->cm_up
, evalcost
);
166 tty
->Wcm
->cc_down
= COST (tty
->Wcm
->cm_down
, evalcost
);
167 tty
->Wcm
->cc_left
= COST (tty
->Wcm
->cm_left
, evalcost
);
168 tty
->Wcm
->cc_right
= COST (tty
->Wcm
->cm_right
, evalcost
);
169 tty
->Wcm
->cc_home
= COST (tty
->Wcm
->cm_home
, evalcost
);
170 tty
->Wcm
->cc_cr
= COST (tty
->Wcm
->cm_cr
, evalcost
);
171 tty
->Wcm
->cc_ll
= COST (tty
->Wcm
->cm_ll
, evalcost
);
172 tty
->Wcm
->cc_tab
= tty
->Wcm
->cm_tabwidth
? COST (tty
->Wcm
->cm_tab
, evalcost
) : BIG
;
175 * These last three are actually minimum costs. When (if) they are
176 * candidates for the least-cost motion, the real cost is computed.
177 * (Note that "0" is the assumed to generate the minimum cost.
178 * While this is not necessarily true, I have yet to see a terminal
179 * for which is not; all the terminals that have variable-cost
180 * cursor motion seem to take straight numeric values. --ACT)
183 tty
->Wcm
->cc_abs
= CMCOST (tty
->Wcm
->cm_abs
, evalcost
);
184 tty
->Wcm
->cc_habs
= CMCOST (tty
->Wcm
->cm_habs
, evalcost
);
185 tty
->Wcm
->cc_vabs
= CMCOST (tty
->Wcm
->cm_vabs
, evalcost
);
192 * Calculate the cost to move from (srcy, srcx) to (dsty, dstx) using
193 * up and down, and left and right, motions, and tabs. If doit is set
194 * actually perform the motion.
198 calccost (struct tty_display_info
*tty
,
199 int srcy
, int srcx
, int dsty
, int dstx
, int doit
)
212 /* If have just wrapped on a terminal with xn,
213 don't believe the cursor position: give up here
214 and force use of absolute positioning. */
216 if (curX (tty
) == tty
->Wcm
->cm_cols
)
220 if ((deltay
= dsty
- srcy
) == 0)
223 p
= tty
->Wcm
->cm_up
, c
= tty
->Wcm
->cc_up
, deltay
= -deltay
;
225 p
= tty
->Wcm
->cm_down
, c
= tty
->Wcm
->cc_down
;
226 if (c
== BIG
) { /* caint get thar from here */
231 totalcost
= c
* deltay
;
233 while (--deltay
>= 0)
234 emacs_tputs (tty
, p
, 1, cmputc
);
236 if ((deltax
= dstx
- srcx
) == 0)
239 p
= tty
->Wcm
->cm_left
, c
= tty
->Wcm
->cc_left
, deltax
= -deltax
;
240 goto dodelta
; /* skip all the tab junk */
242 /* Tabs (the toughie) */
243 if (tty
->Wcm
->cc_tab
>= BIG
|| !tty
->Wcm
->cm_usetabs
)
244 goto olddelta
; /* forget it! */
247 * ntabs is # tabs towards but not past dstx; n2tabs is one more
248 * (ie past dstx), but this is only valid if that is not past the
249 * right edge of the screen. We can check that at the same time
250 * as we figure out where we would be if we use the tabs (which
251 * we will put into tabx (for ntabs) and tab2x (for n2tabs)).
254 ntabs
= (deltax
+ srcx
% tty
->Wcm
->cm_tabwidth
) / tty
->Wcm
->cm_tabwidth
;
256 tabx
= (srcx
/ tty
->Wcm
->cm_tabwidth
+ ntabs
) * tty
->Wcm
->cm_tabwidth
;
257 tab2x
= tabx
+ tty
->Wcm
->cm_tabwidth
;
259 if (tab2x
>= tty
->Wcm
->cm_cols
) /* too far (past edge) */
263 * Now set tabcost to the cost for using ntabs, and c to the cost
264 * for using n2tabs, then pick the minimum.
267 /* cost for ntabs + cost for right motion */
268 tabcost
= ntabs
? ntabs
* tty
->Wcm
->cc_tab
+ (dstx
- tabx
) * tty
->Wcm
->cc_right
271 /* cost for n2tabs + cost for left motion */
272 c
= n2tabs
? n2tabs
* tty
->Wcm
->cc_tab
+ (tab2x
- dstx
) * tty
->Wcm
->cc_left
275 if (c
< tabcost
) /* then cheaper to overshoot & back up */
276 ntabs
= n2tabs
, tabcost
= c
, tabx
= tab2x
;
278 if (tabcost
>= BIG
) /* caint use tabs */
282 * See if tabcost is less than just moving right
285 if (tabcost
< (deltax
* tty
->Wcm
->cc_right
)) {
286 totalcost
+= tabcost
; /* use the tabs */
289 emacs_tputs (tty
, tty
->Wcm
->cm_tab
, 1, cmputc
);
294 * Now might as well just recompute the delta.
298 if ((deltax
= dstx
- srcx
) == 0)
302 p
= tty
->Wcm
->cm_right
, c
= tty
->Wcm
->cc_right
;
304 p
= tty
->Wcm
->cm_left
, c
= tty
->Wcm
->cc_left
, deltax
= -deltax
;
307 if (c
== BIG
) { /* caint get thar from here */
313 totalcost
+= c
* deltax
;
315 while (--deltax
>= 0)
316 emacs_tputs (tty
, p
, 1, cmputc
);
334 cmgoto (tty
, row
, col
)
335 struct tty_display_info
*tty
;
347 /* First the degenerate case */
348 if (row
== curY (tty
) && col
== curX (tty
)) /* already there */
351 if (curY (tty
) >= 0 && curX (tty
) >= 0)
353 /* We may have quick ways to go to the upper-left, bottom-left,
354 * start-of-line, or start-of-next-line. Or it might be best to
355 * start where we are. Examine the options, and pick the cheapest.
358 relcost
= calccost (tty
, curY (tty
), curX (tty
), row
, col
, 0);
360 if ((homecost
= tty
->Wcm
->cc_home
) < BIG
)
361 homecost
+= calccost (tty
, 0, 0, row
, col
, 0);
362 if (homecost
< relcost
)
363 relcost
= homecost
, use
= USEHOME
;
364 if ((llcost
= tty
->Wcm
->cc_ll
) < BIG
)
365 llcost
+= calccost (tty
, tty
->Wcm
->cm_rows
- 1, 0, row
, col
, 0);
366 if (llcost
< relcost
)
367 relcost
= llcost
, use
= USELL
;
368 if ((crcost
= tty
->Wcm
->cc_cr
) < BIG
) {
369 if (tty
->Wcm
->cm_autolf
)
370 if (curY (tty
) + 1 >= tty
->Wcm
->cm_rows
)
373 crcost
+= calccost (tty
, curY (tty
) + 1, 0, row
, col
, 0);
375 crcost
+= calccost (tty
, curY (tty
), 0, row
, col
, 0);
377 if (crcost
< relcost
)
378 relcost
= crcost
, use
= USECR
;
379 directcost
= tty
->Wcm
->cc_abs
, dcm
= tty
->Wcm
->cm_abs
;
380 if (row
== curY (tty
) && tty
->Wcm
->cc_habs
< BIG
)
381 directcost
= tty
->Wcm
->cc_habs
, dcm
= tty
->Wcm
->cm_habs
;
382 else if (col
== curX (tty
) && tty
->Wcm
->cc_vabs
< BIG
)
383 directcost
= tty
->Wcm
->cc_vabs
, dcm
= tty
->Wcm
->cm_vabs
;
387 directcost
= 0, relcost
= 100000;
388 dcm
= tty
->Wcm
->cm_abs
;
392 * In the following comparison, the = in <= is because when the costs
393 * are the same, it looks nicer (I think) to move directly there.
395 if (directcost
<= relcost
)
397 /* compute REAL direct cost */
399 p
= (dcm
== tty
->Wcm
->cm_habs
400 ? tgoto (dcm
, row
, col
)
401 : tgoto (dcm
, col
, row
));
402 emacs_tputs (tty
, p
, 1, evalcost
);
404 { /* really is cheaper */
405 emacs_tputs (tty
, p
, 1, cmputc
);
406 curY (tty
) = row
, curX (tty
) = col
;
414 emacs_tputs (tty
, tty
->Wcm
->cm_home
, 1, cmputc
);
415 curY (tty
) = 0, curX (tty
) = 0;
419 emacs_tputs (tty
, tty
->Wcm
->cm_ll
, 1, cmputc
);
420 curY (tty
) = tty
->Wcm
->cm_rows
- 1, curX (tty
) = 0;
424 emacs_tputs (tty
, tty
->Wcm
->cm_cr
, 1, cmputc
);
425 if (tty
->Wcm
->cm_autolf
)
431 (void) calccost (tty
, curY (tty
), curX (tty
), row
, col
, 1);
432 curY (tty
) = row
, curX (tty
) = col
;
435 /* Clear out all terminal info.
436 Used before copying into it the info on the actual terminal.
440 Wcm_clear (struct tty_display_info
*tty
)
442 bzero (tty
->Wcm
, sizeof (struct cm
));
449 * Return 0 if can do CM.
450 * Return -1 if cannot.
451 * Return -2 if size not specified.
455 Wcm_init (struct tty_display_info
*tty
)
458 if (tty
->Wcm
->cm_abs
&& !tty
->Wcm
->cm_ds
)
461 if (tty
->Wcm
->cm_abs
)
463 /* Require up and left, and, if no absolute, down and right */
464 if (!tty
->Wcm
->cm_up
|| !tty
->Wcm
->cm_left
)
466 if (!tty
->Wcm
->cm_abs
&& (!tty
->Wcm
->cm_down
|| !tty
->Wcm
->cm_right
))
468 /* Check that we know the size of the screen.... */
469 if (tty
->Wcm
->cm_rows
<= 0 || tty
->Wcm
->cm_cols
<= 0)
474 /* arch-tag: bcf64c02-00f6-44ef-94b6-c56eab5b3dc4
475 (do not change this comment) */