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d427b66a JB |
1 | /* Cursor motion subroutines for GNU Emacs. |
2 | Copyright (C) 1985 Free Software Foundation, Inc. | |
3 | based primarily on public domain code written by Chris Torek | |
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 | |
4fc440b7 | 9 | the Free Software Foundation; either version 2, or (at your option) |
d427b66a JB |
10 | 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; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
20 | ||
21 | ||
18160b98 | 22 | #include <config.h> |
d427b66a JB |
23 | #include <stdio.h> |
24 | #include "cm.h" | |
25 | #include "termhooks.h" | |
26 | ||
27 | #define BIG 9999 /* 9999 good on VAXen. For 16 bit machines | |
28 | use about 2000.... */ | |
29 | ||
30 | char *tgoto (); | |
31 | ||
32 | extern char *BC, *UP; | |
33 | ||
34 | int cost; /* sums up costs */ | |
35 | ||
36 | /* ARGSUSED */ | |
37 | evalcost (c) | |
38 | char c; | |
39 | { | |
40 | cost++; | |
97f11a9d | 41 | return c; |
d427b66a JB |
42 | } |
43 | ||
d427b66a JB |
44 | cmputc (c) |
45 | char c; | |
46 | { | |
47 | if (termscript) | |
48 | fputc (c & 0177, termscript); | |
49 | putchar (c & 0177); | |
97f11a9d | 50 | return c; |
d427b66a JB |
51 | } |
52 | ||
53 | /* NEXT TWO ARE DONE WITH MACROS */ | |
54 | #if 0 | |
55 | /* | |
56 | * Assume the cursor is at row row, column col. Normally used only after | |
57 | * clearing the screen, when the cursor is at (0, 0), but what the heck, | |
58 | * let's let the guy put it anywhere. | |
59 | */ | |
60 | ||
61 | static | |
62 | at (row, col) { | |
63 | curY = row; | |
64 | curX = col; | |
65 | } | |
66 | ||
67 | /* | |
68 | * Add n columns to the current cursor position. | |
69 | */ | |
70 | ||
71 | static | |
72 | addcol (n) { | |
73 | curX += n; | |
74 | ||
75 | /* | |
76 | * If cursor hit edge of screen, what happened? | |
77 | * N.B.: DO NOT!! write past edge of screen. If you do, you | |
78 | * deserve what you get. Furthermore, on terminals with | |
79 | * autowrap (but not magicwrap), don't write in the last column | |
80 | * of the last line. | |
81 | */ | |
82 | ||
83 | if (curX == Wcm.cm_cols) { | |
84 | /* | |
85 | * Well, if magicwrap, still there, past the edge of the | |
86 | * screen (!). If autowrap, on the col 0 of the next line. | |
87 | * Otherwise on last column. | |
88 | */ | |
89 | ||
90 | if (Wcm.cm_magicwrap) | |
91 | ; /* "limbo" */ | |
92 | else if (Wcm.cm_autowrap) { | |
93 | curX = 0; | |
94 | curY++; /* Beware end of screen! */ | |
95 | } | |
96 | else | |
97 | curX--; | |
98 | } | |
99 | } | |
100 | #endif | |
101 | ||
902a3b86 KH |
102 | /* |
103 | * Terminals with magicwrap (xn) don't all behave identically. | |
104 | * The VT100 leaves the cursor in the last column but will wrap before | |
105 | * printing the next character. I hear that the Concept terminal does | |
106 | * the wrap immediately but ignores the next newline it sees. And some | |
107 | * terminals just have buggy firmware, and think that the cursor is still | |
108 | * in limbo if we use direct cursor addressing from the phantom column. | |
109 | * The only guaranteed safe thing to do is to emit a CRLF immediately | |
110 | * after we reach the last column; this takes us to a known state. | |
111 | */ | |
112 | void | |
113 | cmcheckmagic () | |
114 | { | |
115 | if (curX == FrameCols) | |
116 | { | |
117 | if (!MagicWrap || curY >= FrameRows - 1) | |
118 | abort (); | |
119 | if (termscript) | |
120 | putc ('\r', termscript); | |
121 | putchar ('\r'); | |
122 | if (termscript) | |
123 | putc ('\n', termscript); | |
124 | putchar ('\n'); | |
125 | curX = 0; | |
126 | curY++; | |
127 | } | |
128 | } | |
129 | ||
130 | ||
d427b66a JB |
131 | /* |
132 | * (Re)Initialize the cost factors, given the output speed of the terminal | |
133 | * in the variable ospeed. (Note: this holds B300, B9600, etc -- ie stuff | |
134 | * out of <sgtty.h>.) | |
135 | */ | |
136 | ||
137 | cmcostinit () | |
138 | { | |
139 | char *p; | |
140 | ||
141 | #define COST(x,e) (x ? (cost = 0, tputs (x, 1, e), cost) : BIG) | |
142 | #define CMCOST(x,e) ((x == 0) ? BIG : (p = tgoto(x, 0, 0), COST(p ,e))) | |
143 | ||
144 | Wcm.cc_up = COST (Wcm.cm_up, evalcost); | |
145 | Wcm.cc_down = COST (Wcm.cm_down, evalcost); | |
146 | Wcm.cc_left = COST (Wcm.cm_left, evalcost); | |
147 | Wcm.cc_right = COST (Wcm.cm_right, evalcost); | |
148 | Wcm.cc_home = COST (Wcm.cm_home, evalcost); | |
149 | Wcm.cc_cr = COST (Wcm.cm_cr, evalcost); | |
150 | Wcm.cc_ll = COST (Wcm.cm_ll, evalcost); | |
151 | Wcm.cc_tab = Wcm.cm_tabwidth ? COST (Wcm.cm_tab, evalcost) : BIG; | |
152 | ||
153 | /* | |
154 | * These last three are actually minimum costs. When (if) they are | |
155 | * candidates for the least-cost motion, the real cost is computed. | |
156 | * (Note that "0" is the assumed to generate the minimum cost. | |
157 | * While this is not necessarily true, I have yet to see a terminal | |
158 | * for which is not; all the terminals that have variable-cost | |
159 | * cursor motion seem to take straight numeric values. --ACT) | |
160 | */ | |
161 | ||
162 | Wcm.cc_abs = CMCOST (Wcm.cm_abs, evalcost); | |
163 | Wcm.cc_habs = CMCOST (Wcm.cm_habs, evalcost); | |
164 | Wcm.cc_vabs = CMCOST (Wcm.cm_vabs, evalcost); | |
165 | ||
166 | #undef CMCOST | |
167 | #undef COST | |
168 | } | |
169 | ||
170 | /* | |
171 | * Calculate the cost to move from (srcy, srcx) to (dsty, dstx) using | |
172 | * up and down, and left and right, motions, and tabs. If doit is set | |
173 | * actually perform the motion. | |
174 | */ | |
175 | ||
176 | static | |
177 | calccost (srcy, srcx, dsty, dstx, doit) | |
178 | { | |
179 | register int deltay, | |
180 | deltax, | |
181 | c, | |
182 | totalcost; | |
183 | int ntabs, | |
184 | n2tabs, | |
185 | tabx, | |
186 | tab2x, | |
187 | tabcost; | |
188 | register char *p; | |
189 | ||
190 | /* If have just wrapped on a terminal with xn, | |
191 | don't believe the cursor position: give up here | |
192 | and force use of absolute positioning. */ | |
193 | ||
194 | if (curX == Wcm.cm_cols) | |
195 | goto fail; | |
196 | ||
197 | totalcost = 0; | |
198 | if ((deltay = dsty - srcy) == 0) | |
199 | goto x; | |
200 | if (deltay < 0) | |
201 | p = Wcm.cm_up, c = Wcm.cc_up, deltay = -deltay; | |
202 | else | |
203 | p = Wcm.cm_down, c = Wcm.cc_down; | |
204 | if (c == BIG) { /* caint get thar from here */ | |
205 | if (doit) | |
206 | printf ("OOPS"); | |
207 | return c; | |
208 | } | |
209 | totalcost = c * deltay; | |
210 | if (doit) | |
211 | while (--deltay >= 0) | |
212 | tputs (p, 1, cmputc); | |
213 | x: | |
214 | if ((deltax = dstx - srcx) == 0) | |
215 | goto done; | |
216 | if (deltax < 0) { | |
217 | p = Wcm.cm_left, c = Wcm.cc_left, deltax = -deltax; | |
218 | goto dodelta; /* skip all the tab junk */ | |
219 | } | |
220 | /* Tabs (the toughie) */ | |
221 | if (Wcm.cc_tab >= BIG || !Wcm.cm_usetabs) | |
222 | goto olddelta; /* forget it! */ | |
223 | ||
224 | /* | |
225 | * ntabs is # tabs towards but not past dstx; n2tabs is one more | |
226 | * (ie past dstx), but this is only valid if that is not past the | |
227 | * right edge of the screen. We can check that at the same time | |
228 | * as we figure out where we would be if we use the tabs (which | |
229 | * we will put into tabx (for ntabs) and tab2x (for n2tabs)). | |
230 | */ | |
231 | ||
232 | ntabs = (deltax + srcx % Wcm.cm_tabwidth) / Wcm.cm_tabwidth; | |
233 | n2tabs = ntabs + 1; | |
234 | tabx = (srcx / Wcm.cm_tabwidth + ntabs) * Wcm.cm_tabwidth; | |
235 | tab2x = tabx + Wcm.cm_tabwidth; | |
236 | ||
237 | if (tab2x >= Wcm.cm_cols) /* too far (past edge) */ | |
238 | n2tabs = 0; | |
239 | ||
240 | /* | |
241 | * Now set tabcost to the cost for using ntabs, and c to the cost | |
242 | * for using n2tabs, then pick the minimum. | |
243 | */ | |
244 | ||
245 | /* cost for ntabs + cost for right motion */ | |
246 | tabcost = ntabs ? ntabs * Wcm.cc_tab + (dstx - tabx) * Wcm.cc_right | |
247 | : BIG; | |
248 | ||
249 | /* cost for n2tabs + cost for left motion */ | |
250 | c = n2tabs ? n2tabs * Wcm.cc_tab + (tab2x - dstx) * Wcm.cc_left | |
251 | : BIG; | |
252 | ||
253 | if (c < tabcost) /* then cheaper to overshoot & back up */ | |
254 | ntabs = n2tabs, tabcost = c, tabx = tab2x; | |
255 | ||
256 | if (tabcost >= BIG) /* caint use tabs */ | |
257 | goto newdelta; | |
258 | ||
259 | /* | |
260 | * See if tabcost is less than just moving right | |
261 | */ | |
262 | ||
263 | if (tabcost < (deltax * Wcm.cc_right)) { | |
264 | totalcost += tabcost; /* use the tabs */ | |
265 | if (doit) | |
266 | while (--ntabs >= 0) | |
267 | tputs (Wcm.cm_tab, 1, cmputc); | |
268 | srcx = tabx; | |
269 | } | |
270 | ||
271 | /* | |
272 | * Now might as well just recompute the delta. | |
273 | */ | |
274 | ||
275 | newdelta: | |
276 | if ((deltax = dstx - srcx) == 0) | |
277 | goto done; | |
278 | olddelta: | |
279 | if (deltax > 0) | |
280 | p = Wcm.cm_right, c = Wcm.cc_right; | |
281 | else | |
282 | p = Wcm.cm_left, c = Wcm.cc_left, deltax = -deltax; | |
283 | ||
284 | dodelta: | |
285 | if (c == BIG) { /* caint get thar from here */ | |
286 | fail: | |
287 | if (doit) | |
288 | printf ("OOPS"); | |
289 | return BIG; | |
290 | } | |
291 | totalcost += c * deltax; | |
292 | if (doit) | |
293 | while (--deltax >= 0) | |
294 | tputs (p, 1, cmputc); | |
295 | done: | |
296 | return totalcost; | |
297 | } | |
298 | ||
299 | #if 0 | |
300 | losecursor () | |
301 | { | |
302 | curY = -1; | |
303 | } | |
304 | #endif | |
305 | ||
306 | #define USEREL 0 | |
307 | #define USEHOME 1 | |
308 | #define USELL 2 | |
309 | #define USECR 3 | |
310 | ||
311 | cmgoto (row, col) | |
312 | { | |
313 | int homecost, | |
314 | crcost, | |
315 | llcost, | |
316 | relcost, | |
317 | directcost; | |
318 | int use; | |
319 | char *p, | |
320 | *dcm; | |
321 | ||
322 | /* First the degenerate case */ | |
323 | if (row == curY && col == curX) /* already there */ | |
324 | return; | |
325 | ||
326 | if (curY >= 0 && curX >= 0) | |
327 | { | |
328 | /* We may have quick ways to go to the upper-left, bottom-left, | |
329 | * start-of-line, or start-of-next-line. Or it might be best to | |
330 | * start where we are. Examine the options, and pick the cheapest. | |
331 | */ | |
332 | ||
333 | relcost = calccost (curY, curX, row, col, 0); | |
334 | use = USEREL; | |
335 | if ((homecost = Wcm.cc_home) < BIG) | |
336 | homecost += calccost (0, 0, row, col, 0); | |
337 | if (homecost < relcost) | |
338 | relcost = homecost, use = USEHOME; | |
339 | if ((llcost = Wcm.cc_ll) < BIG) | |
340 | llcost += calccost (Wcm.cm_rows - 1, 0, row, col, 0); | |
341 | if (llcost < relcost) | |
342 | relcost = llcost, use = USELL; | |
343 | if ((crcost = Wcm.cc_cr) < BIG) { | |
344 | if (Wcm.cm_autolf) | |
345 | if (curY + 1 >= Wcm.cm_rows) | |
346 | crcost = BIG; | |
347 | else | |
348 | crcost += calccost (curY + 1, 0, row, col, 0); | |
349 | else | |
350 | crcost += calccost (curY, 0, row, col, 0); | |
351 | } | |
352 | if (crcost < relcost) | |
353 | relcost = crcost, use = USECR; | |
354 | directcost = Wcm.cc_abs, dcm = Wcm.cm_abs; | |
355 | if (row == curY && Wcm.cc_habs < BIG) | |
356 | directcost = Wcm.cc_habs, dcm = Wcm.cm_habs; | |
357 | else if (col == curX && Wcm.cc_vabs < BIG) | |
358 | directcost = Wcm.cc_vabs, dcm = Wcm.cm_vabs; | |
359 | } | |
360 | else | |
361 | { | |
362 | directcost = 0, relcost = 100000; | |
363 | dcm = Wcm.cm_abs; | |
364 | } | |
365 | ||
366 | /* | |
367 | * In the following comparison, the = in <= is because when the costs | |
368 | * are the same, it looks nicer (I think) to move directly there. | |
369 | */ | |
370 | if (directcost <= relcost) | |
371 | { | |
372 | /* compute REAL direct cost */ | |
373 | cost = 0; | |
374 | p = dcm == Wcm.cm_habs ? tgoto (dcm, row, col) : | |
375 | tgoto (dcm, col, row); | |
376 | tputs (p, 1, evalcost); | |
377 | if (cost <= relcost) | |
378 | { /* really is cheaper */ | |
379 | tputs (p, 1, cmputc); | |
380 | curY = row, curX = col; | |
381 | return; | |
382 | } | |
383 | } | |
384 | ||
385 | switch (use) | |
386 | { | |
387 | case USEHOME: | |
388 | tputs (Wcm.cm_home, 1, cmputc); | |
389 | curY = 0, curX = 0; | |
390 | break; | |
391 | ||
392 | case USELL: | |
393 | tputs (Wcm.cm_ll, 1, cmputc); | |
394 | curY = Wcm.cm_rows - 1, curX = 0; | |
395 | break; | |
396 | ||
397 | case USECR: | |
398 | tputs (Wcm.cm_cr, 1, cmputc); | |
399 | if (Wcm.cm_autolf) | |
400 | curY++; | |
401 | curX = 0; | |
402 | break; | |
403 | } | |
404 | ||
405 | (void) calccost (curY, curX, row, col, 1); | |
406 | curY = row, curX = col; | |
407 | } | |
408 | ||
409 | /* Clear out all terminal info. | |
410 | Used before copying into it the info on the actual terminal. | |
411 | */ | |
412 | ||
413 | Wcm_clear () | |
414 | { | |
415 | bzero (&Wcm, sizeof Wcm); | |
416 | UP = 0; | |
417 | BC = 0; | |
418 | } | |
419 | ||
420 | /* | |
421 | * Initialized stuff | |
422 | * Return 0 if can do CM. | |
423 | * Return -1 if cannot. | |
424 | * Return -2 if size not specified. | |
425 | */ | |
426 | ||
427 | Wcm_init () | |
428 | { | |
429 | #if 0 | |
430 | if (Wcm.cm_abs && !Wcm.cm_ds) | |
431 | return 0; | |
432 | #endif | |
433 | if (Wcm.cm_abs) | |
434 | return 0; | |
435 | /* Require up and left, and, if no absolute, down and right */ | |
436 | if (!Wcm.cm_up || !Wcm.cm_left) | |
437 | return - 1; | |
438 | if (!Wcm.cm_abs && (!Wcm.cm_down || !Wcm.cm_right)) | |
439 | return - 1; | |
440 | /* Check that we know the size of the screen.... */ | |
441 | if (Wcm.cm_rows <= 0 || Wcm.cm_cols <= 0) | |
442 | return - 2; | |
443 | return 0; | |
444 | } |