1 /* Cursor motion subroutines for GNU Emacs.
2 Copyright (C) 1985, 1995, 2001, 2002, 2003, 2004,
3 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 based primarily on public domain code written by Chris Torek
6 This file is part of GNU Emacs.
8 GNU Emacs is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 GNU Emacs is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
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
36 extern void tputs
P_ ((const char *, int, int (*)(int)));
37 extern char *tgoto
P_ ((const char *, int, int));
39 #define BIG 9999 /* 9999 good on VAXen. For 16 bit machines
44 int cost
; /* sums up costs */
55 /* The terminal to use for low-level output. */
56 struct tty_display_info
*current_tty
;
62 if (current_tty
->termscript
)
63 putc (c
& 0177, current_tty
->termscript
);
64 putc (c
& 0177, current_tty
->output
);
68 /* NEXT TWO ARE DONE WITH MACROS */
71 * Assume the cursor is at row row, column col. Normally used only after
72 * clearing the screen, when the cursor is at (0, 0), but what the heck,
73 * let's let the guy put it anywhere.
83 * Add n columns to the current cursor position.
91 * If cursor hit edge of screen, what happened?
92 * N.B.: DO NOT!! write past edge of screen. If you do, you
93 * deserve what you get. Furthermore, on terminals with
94 * autowrap (but not magicwrap), don't write in the last column
98 if (curX (tty
) == tty
->Wcm
->cm_cols
) {
100 * Well, if magicwrap, still there, past the edge of the
101 * screen (!). If autowrap, on the col 0 of the next line.
102 * Otherwise on last column.
105 if (tty
->Wcm
->cm_magicwrap
)
107 else if (tty
->Wcm
->cm_autowrap
) {
109 curY (tty
) ++; /* Beware end of screen! */
118 * Terminals with magicwrap (xn) don't all behave identically.
119 * The VT100 leaves the cursor in the last column but will wrap before
120 * printing the next character. I hear that the Concept terminal does
121 * the wrap immediately but ignores the next newline it sees. And some
122 * terminals just have buggy firmware, and think that the cursor is still
123 * in limbo if we use direct cursor addressing from the phantom column.
124 * The only guaranteed safe thing to do is to emit a CRLF immediately
125 * after we reach the last column; this takes us to a known state.
128 cmcheckmagic (struct tty_display_info
*tty
)
130 if (curX (tty
) == FrameCols (tty
))
132 if (!MagicWrap (tty
) || curY (tty
) >= FrameRows (tty
) - 1)
135 putc ('\r', tty
->termscript
);
136 putc ('\r', tty
->output
);
138 putc ('\n', tty
->termscript
);
139 putc ('\n', tty
->output
);
147 * (Re)Initialize the cost factors, given the output speed of the terminal
148 * in the variable ospeed. (Note: this holds B300, B9600, etc -- ie stuff
153 cmcostinit (struct tty_display_info
*tty
)
157 #define COST(x,e) (x ? (cost = 0, tputs (x, 1, e), cost) : BIG)
158 #define CMCOST(x,e) ((x == 0) ? BIG : (p = tgoto(x, 0, 0), COST(p ,e)))
160 tty
->Wcm
->cc_up
= COST (tty
->Wcm
->cm_up
, evalcost
);
161 tty
->Wcm
->cc_down
= COST (tty
->Wcm
->cm_down
, evalcost
);
162 tty
->Wcm
->cc_left
= COST (tty
->Wcm
->cm_left
, evalcost
);
163 tty
->Wcm
->cc_right
= COST (tty
->Wcm
->cm_right
, evalcost
);
164 tty
->Wcm
->cc_home
= COST (tty
->Wcm
->cm_home
, evalcost
);
165 tty
->Wcm
->cc_cr
= COST (tty
->Wcm
->cm_cr
, evalcost
);
166 tty
->Wcm
->cc_ll
= COST (tty
->Wcm
->cm_ll
, evalcost
);
167 tty
->Wcm
->cc_tab
= tty
->Wcm
->cm_tabwidth
? COST (tty
->Wcm
->cm_tab
, evalcost
) : BIG
;
170 * These last three are actually minimum costs. When (if) they are
171 * candidates for the least-cost motion, the real cost is computed.
172 * (Note that "0" is the assumed to generate the minimum cost.
173 * While this is not necessarily true, I have yet to see a terminal
174 * for which is not; all the terminals that have variable-cost
175 * cursor motion seem to take straight numeric values. --ACT)
178 tty
->Wcm
->cc_abs
= CMCOST (tty
->Wcm
->cm_abs
, evalcost
);
179 tty
->Wcm
->cc_habs
= CMCOST (tty
->Wcm
->cm_habs
, evalcost
);
180 tty
->Wcm
->cc_vabs
= CMCOST (tty
->Wcm
->cm_vabs
, evalcost
);
187 * Calculate the cost to move from (srcy, srcx) to (dsty, dstx) using
188 * up and down, and left and right, motions, and tabs. If doit is set
189 * actually perform the motion.
193 calccost (struct tty_display_info
*tty
,
194 int srcy
, int srcx
, int dsty
, int dstx
, int doit
)
207 /* If have just wrapped on a terminal with xn,
208 don't believe the cursor position: give up here
209 and force use of absolute positioning. */
211 if (curX (tty
) == tty
->Wcm
->cm_cols
)
215 if ((deltay
= dsty
- srcy
) == 0)
218 p
= tty
->Wcm
->cm_up
, c
= tty
->Wcm
->cc_up
, deltay
= -deltay
;
220 p
= tty
->Wcm
->cm_down
, c
= tty
->Wcm
->cc_down
;
221 if (c
== BIG
) { /* caint get thar from here */
226 totalcost
= c
* deltay
;
228 while (--deltay
>= 0)
229 emacs_tputs (tty
, p
, 1, cmputc
);
231 if ((deltax
= dstx
- srcx
) == 0)
234 p
= tty
->Wcm
->cm_left
, c
= tty
->Wcm
->cc_left
, deltax
= -deltax
;
235 goto dodelta
; /* skip all the tab junk */
237 /* Tabs (the toughie) */
238 if (tty
->Wcm
->cc_tab
>= BIG
|| !tty
->Wcm
->cm_usetabs
)
239 goto olddelta
; /* forget it! */
242 * ntabs is # tabs towards but not past dstx; n2tabs is one more
243 * (ie past dstx), but this is only valid if that is not past the
244 * right edge of the screen. We can check that at the same time
245 * as we figure out where we would be if we use the tabs (which
246 * we will put into tabx (for ntabs) and tab2x (for n2tabs)).
249 ntabs
= (deltax
+ srcx
% tty
->Wcm
->cm_tabwidth
) / tty
->Wcm
->cm_tabwidth
;
251 tabx
= (srcx
/ tty
->Wcm
->cm_tabwidth
+ ntabs
) * tty
->Wcm
->cm_tabwidth
;
252 tab2x
= tabx
+ tty
->Wcm
->cm_tabwidth
;
254 if (tab2x
>= tty
->Wcm
->cm_cols
) /* too far (past edge) */
258 * Now set tabcost to the cost for using ntabs, and c to the cost
259 * for using n2tabs, then pick the minimum.
262 /* cost for ntabs + cost for right motion */
263 tabcost
= ntabs
? ntabs
* tty
->Wcm
->cc_tab
+ (dstx
- tabx
) * tty
->Wcm
->cc_right
266 /* cost for n2tabs + cost for left motion */
267 c
= n2tabs
? n2tabs
* tty
->Wcm
->cc_tab
+ (tab2x
- dstx
) * tty
->Wcm
->cc_left
270 if (c
< tabcost
) /* then cheaper to overshoot & back up */
271 ntabs
= n2tabs
, tabcost
= c
, tabx
= tab2x
;
273 if (tabcost
>= BIG
) /* caint use tabs */
277 * See if tabcost is less than just moving right
280 if (tabcost
< (deltax
* tty
->Wcm
->cc_right
)) {
281 totalcost
+= tabcost
; /* use the tabs */
284 emacs_tputs (tty
, tty
->Wcm
->cm_tab
, 1, cmputc
);
289 * Now might as well just recompute the delta.
293 if ((deltax
= dstx
- srcx
) == 0)
297 p
= tty
->Wcm
->cm_right
, c
= tty
->Wcm
->cc_right
;
299 p
= tty
->Wcm
->cm_left
, c
= tty
->Wcm
->cc_left
, deltax
= -deltax
;
302 if (c
== BIG
) { /* caint get thar from here */
308 totalcost
+= c
* deltax
;
310 while (--deltax
>= 0)
311 emacs_tputs (tty
, p
, 1, cmputc
);
329 cmgoto (tty
, row
, col
)
330 struct tty_display_info
*tty
;
342 /* First the degenerate case */
343 if (row
== curY (tty
) && col
== curX (tty
)) /* already there */
346 if (curY (tty
) >= 0 && curX (tty
) >= 0)
348 /* We may have quick ways to go to the upper-left, bottom-left,
349 * start-of-line, or start-of-next-line. Or it might be best to
350 * start where we are. Examine the options, and pick the cheapest.
353 relcost
= calccost (tty
, curY (tty
), curX (tty
), row
, col
, 0);
355 if ((homecost
= tty
->Wcm
->cc_home
) < BIG
)
356 homecost
+= calccost (tty
, 0, 0, row
, col
, 0);
357 if (homecost
< relcost
)
358 relcost
= homecost
, use
= USEHOME
;
359 if ((llcost
= tty
->Wcm
->cc_ll
) < BIG
)
360 llcost
+= calccost (tty
, tty
->Wcm
->cm_rows
- 1, 0, row
, col
, 0);
361 if (llcost
< relcost
)
362 relcost
= llcost
, use
= USELL
;
363 if ((crcost
= tty
->Wcm
->cc_cr
) < BIG
) {
364 if (tty
->Wcm
->cm_autolf
)
365 if (curY (tty
) + 1 >= tty
->Wcm
->cm_rows
)
368 crcost
+= calccost (tty
, curY (tty
) + 1, 0, row
, col
, 0);
370 crcost
+= calccost (tty
, curY (tty
), 0, row
, col
, 0);
372 if (crcost
< relcost
)
373 relcost
= crcost
, use
= USECR
;
374 directcost
= tty
->Wcm
->cc_abs
, dcm
= tty
->Wcm
->cm_abs
;
375 if (row
== curY (tty
) && tty
->Wcm
->cc_habs
< BIG
)
376 directcost
= tty
->Wcm
->cc_habs
, dcm
= tty
->Wcm
->cm_habs
;
377 else if (col
== curX (tty
) && tty
->Wcm
->cc_vabs
< BIG
)
378 directcost
= tty
->Wcm
->cc_vabs
, dcm
= tty
->Wcm
->cm_vabs
;
382 directcost
= 0, relcost
= 100000;
383 dcm
= tty
->Wcm
->cm_abs
;
387 * In the following comparison, the = in <= is because when the costs
388 * are the same, it looks nicer (I think) to move directly there.
390 if (directcost
<= relcost
)
392 /* compute REAL direct cost */
394 p
= (dcm
== tty
->Wcm
->cm_habs
395 ? tgoto (dcm
, row
, col
)
396 : tgoto (dcm
, col
, row
));
397 emacs_tputs (tty
, p
, 1, evalcost
);
399 { /* really is cheaper */
400 emacs_tputs (tty
, p
, 1, cmputc
);
401 curY (tty
) = row
, curX (tty
) = col
;
409 emacs_tputs (tty
, tty
->Wcm
->cm_home
, 1, cmputc
);
410 curY (tty
) = 0, curX (tty
) = 0;
414 emacs_tputs (tty
, tty
->Wcm
->cm_ll
, 1, cmputc
);
415 curY (tty
) = tty
->Wcm
->cm_rows
- 1, curX (tty
) = 0;
419 emacs_tputs (tty
, tty
->Wcm
->cm_cr
, 1, cmputc
);
420 if (tty
->Wcm
->cm_autolf
)
426 (void) calccost (tty
, curY (tty
), curX (tty
), row
, col
, 1);
427 curY (tty
) = row
, curX (tty
) = col
;
430 /* Clear out all terminal info.
431 Used before copying into it the info on the actual terminal.
435 Wcm_clear (struct tty_display_info
*tty
)
437 bzero (tty
->Wcm
, sizeof (struct cm
));
444 * Return 0 if can do CM.
445 * Return -1 if cannot.
446 * Return -2 if size not specified.
450 Wcm_init (struct tty_display_info
*tty
)
453 if (tty
->Wcm
->cm_abs
&& !tty
->Wcm
->cm_ds
)
456 if (tty
->Wcm
->cm_abs
)
458 /* Require up and left, and, if no absolute, down and right */
459 if (!tty
->Wcm
->cm_up
|| !tty
->Wcm
->cm_left
)
461 if (!tty
->Wcm
->cm_abs
&& (!tty
->Wcm
->cm_down
|| !tty
->Wcm
->cm_right
))
463 /* Check that we know the size of the screen.... */
464 if (tty
->Wcm
->cm_rows
<= 0 || tty
->Wcm
->cm_cols
<= 0)
469 /* arch-tag: bcf64c02-00f6-44ef-94b6-c56eab5b3dc4
470 (do not change this comment) */