| 1 | /* Cursor motion subroutines for GNU Emacs. |
| 2 | Copyright (C) 1985, 1995, 2001-2012 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 |
| 9 | the Free Software Foundation, either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | GNU Emacs is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | |
| 21 | #include <config.h> |
| 22 | #include <stdio.h> |
| 23 | #include <setjmp.h> |
| 24 | |
| 25 | #include "lisp.h" |
| 26 | #include "frame.h" |
| 27 | #include "cm.h" |
| 28 | #include "termhooks.h" |
| 29 | #include "termchar.h" |
| 30 | #include "tparam.h" |
| 31 | |
| 32 | #define BIG 9999 /* 9999 good on VAXen. For 16 bit machines |
| 33 | use about 2000.... */ |
| 34 | |
| 35 | int cost; /* sums up costs */ |
| 36 | |
| 37 | /* ARGSUSED */ |
| 38 | int |
| 39 | evalcost (int c) |
| 40 | { |
| 41 | cost++; |
| 42 | return c; |
| 43 | } |
| 44 | |
| 45 | /* The terminal to use for low-level output. */ |
| 46 | struct tty_display_info *current_tty; |
| 47 | |
| 48 | int |
| 49 | cmputc (int c) |
| 50 | { |
| 51 | if (current_tty->termscript) |
| 52 | putc (c & 0177, current_tty->termscript); |
| 53 | putc (c & 0177, current_tty->output); |
| 54 | return c; |
| 55 | } |
| 56 | |
| 57 | /* NEXT TWO ARE DONE WITH MACROS */ |
| 58 | #if 0 |
| 59 | /* |
| 60 | * Assume the cursor is at row row, column col. Normally used only after |
| 61 | * clearing the screen, when the cursor is at (0, 0), but what the heck, |
| 62 | * let's let the guy put it anywhere. |
| 63 | */ |
| 64 | |
| 65 | static |
| 66 | at (tty, row, col) { |
| 67 | curY (tty) = row; |
| 68 | curX (tty) = col; |
| 69 | } |
| 70 | |
| 71 | /* |
| 72 | * Add n columns to the current cursor position. |
| 73 | */ |
| 74 | |
| 75 | static |
| 76 | addcol (tty, n) { |
| 77 | curX (tty) += n; |
| 78 | |
| 79 | /* |
| 80 | * If cursor hit edge of screen, what happened? |
| 81 | * N.B.: DO NOT!! write past edge of screen. If you do, you |
| 82 | * deserve what you get. Furthermore, on terminals with |
| 83 | * autowrap (but not magicwrap), don't write in the last column |
| 84 | * of the last line. |
| 85 | */ |
| 86 | |
| 87 | if (curX (tty) == tty->Wcm->cm_cols) { |
| 88 | /* |
| 89 | * Well, if magicwrap, still there, past the edge of the |
| 90 | * screen (!). If autowrap, on the col 0 of the next line. |
| 91 | * Otherwise on last column. |
| 92 | */ |
| 93 | |
| 94 | if (tty->Wcm->cm_magicwrap) |
| 95 | ; /* "limbo" */ |
| 96 | else if (tty->Wcm->cm_autowrap) { |
| 97 | curX (tty) = 0; |
| 98 | curY (tty) ++; /* Beware end of screen! */ |
| 99 | } |
| 100 | else |
| 101 | curX (tty)--; |
| 102 | } |
| 103 | } |
| 104 | #endif |
| 105 | |
| 106 | /* |
| 107 | * Terminals with magicwrap (xn) don't all behave identically. |
| 108 | * The VT100 leaves the cursor in the last column but will wrap before |
| 109 | * printing the next character. I hear that the Concept terminal does |
| 110 | * the wrap immediately but ignores the next newline it sees. And some |
| 111 | * terminals just have buggy firmware, and think that the cursor is still |
| 112 | * in limbo if we use direct cursor addressing from the phantom column. |
| 113 | * The only guaranteed safe thing to do is to emit a CRLF immediately |
| 114 | * after we reach the last column; this takes us to a known state. |
| 115 | */ |
| 116 | void |
| 117 | cmcheckmagic (struct tty_display_info *tty) |
| 118 | { |
| 119 | if (curX (tty) == FrameCols (tty)) |
| 120 | { |
| 121 | if (!MagicWrap (tty) || curY (tty) >= FrameRows (tty) - 1) |
| 122 | emacs_abort (); |
| 123 | if (tty->termscript) |
| 124 | putc ('\r', tty->termscript); |
| 125 | putc ('\r', tty->output); |
| 126 | if (tty->termscript) |
| 127 | putc ('\n', tty->termscript); |
| 128 | putc ('\n', tty->output); |
| 129 | curX (tty) = 0; |
| 130 | curY (tty)++; |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | |
| 135 | /* |
| 136 | * (Re)Initialize the cost factors, given the output speed of the terminal |
| 137 | * in the variable ospeed. (Note: this holds B300, B9600, etc -- ie stuff |
| 138 | * out of <sgtty.h>.) |
| 139 | */ |
| 140 | |
| 141 | void |
| 142 | cmcostinit (struct tty_display_info *tty) |
| 143 | { |
| 144 | char *p; |
| 145 | |
| 146 | #define COST(x,e) (x ? (cost = 0, tputs (x, 1, e), cost) : BIG) |
| 147 | #define CMCOST(x,e) ((x == 0) ? BIG : (p = tgoto(x, 0, 0), COST(p ,e))) |
| 148 | |
| 149 | tty->Wcm->cc_up = COST (tty->Wcm->cm_up, evalcost); |
| 150 | tty->Wcm->cc_down = COST (tty->Wcm->cm_down, evalcost); |
| 151 | tty->Wcm->cc_left = COST (tty->Wcm->cm_left, evalcost); |
| 152 | tty->Wcm->cc_right = COST (tty->Wcm->cm_right, evalcost); |
| 153 | tty->Wcm->cc_home = COST (tty->Wcm->cm_home, evalcost); |
| 154 | tty->Wcm->cc_cr = COST (tty->Wcm->cm_cr, evalcost); |
| 155 | tty->Wcm->cc_ll = COST (tty->Wcm->cm_ll, evalcost); |
| 156 | tty->Wcm->cc_tab = tty->Wcm->cm_tabwidth ? COST (tty->Wcm->cm_tab, evalcost) : BIG; |
| 157 | |
| 158 | /* |
| 159 | * These last three are actually minimum costs. When (if) they are |
| 160 | * candidates for the least-cost motion, the real cost is computed. |
| 161 | * (Note that "0" is the assumed to generate the minimum cost. |
| 162 | * While this is not necessarily true, I have yet to see a terminal |
| 163 | * for which is not; all the terminals that have variable-cost |
| 164 | * cursor motion seem to take straight numeric values. --ACT) |
| 165 | */ |
| 166 | |
| 167 | tty->Wcm->cc_abs = CMCOST (tty->Wcm->cm_abs, evalcost); |
| 168 | tty->Wcm->cc_habs = CMCOST (tty->Wcm->cm_habs, evalcost); |
| 169 | tty->Wcm->cc_vabs = CMCOST (tty->Wcm->cm_vabs, evalcost); |
| 170 | |
| 171 | #undef CMCOST |
| 172 | #undef COST |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Calculate the cost to move from (srcy, srcx) to (dsty, dstx) using |
| 177 | * up and down, and left and right, motions, and tabs. If doit is set |
| 178 | * actually perform the motion. |
| 179 | */ |
| 180 | |
| 181 | static int |
| 182 | calccost (struct tty_display_info *tty, |
| 183 | int srcy, int srcx, int dsty, int dstx, int doit) |
| 184 | { |
| 185 | register int deltay, |
| 186 | deltax, |
| 187 | c, |
| 188 | totalcost; |
| 189 | int ntabs, |
| 190 | n2tabs, |
| 191 | tabx, |
| 192 | tab2x, |
| 193 | tabcost; |
| 194 | register const char *p; |
| 195 | |
| 196 | /* If have just wrapped on a terminal with xn, |
| 197 | don't believe the cursor position: give up here |
| 198 | and force use of absolute positioning. */ |
| 199 | |
| 200 | if (curX (tty) == tty->Wcm->cm_cols) |
| 201 | goto fail; |
| 202 | |
| 203 | totalcost = 0; |
| 204 | if ((deltay = dsty - srcy) == 0) |
| 205 | goto x; |
| 206 | if (deltay < 0) |
| 207 | p = tty->Wcm->cm_up, c = tty->Wcm->cc_up, deltay = -deltay; |
| 208 | else |
| 209 | p = tty->Wcm->cm_down, c = tty->Wcm->cc_down; |
| 210 | if (c == BIG) { /* caint get thar from here */ |
| 211 | if (doit) |
| 212 | printf ("OOPS"); |
| 213 | return c; |
| 214 | } |
| 215 | totalcost = c * deltay; |
| 216 | if (doit) |
| 217 | do |
| 218 | emacs_tputs (tty, p, 1, cmputc); |
| 219 | while (0 < --deltay); |
| 220 | x: |
| 221 | if ((deltax = dstx - srcx) == 0) |
| 222 | goto done; |
| 223 | if (deltax < 0) { |
| 224 | p = tty->Wcm->cm_left, c = tty->Wcm->cc_left, deltax = -deltax; |
| 225 | goto dodelta; /* skip all the tab junk */ |
| 226 | } |
| 227 | /* Tabs (the toughie) */ |
| 228 | if (tty->Wcm->cc_tab >= BIG || !tty->Wcm->cm_usetabs) |
| 229 | goto olddelta; /* forget it! */ |
| 230 | |
| 231 | /* |
| 232 | * ntabs is # tabs towards but not past dstx; n2tabs is one more |
| 233 | * (ie past dstx), but this is only valid if that is not past the |
| 234 | * right edge of the screen. We can check that at the same time |
| 235 | * as we figure out where we would be if we use the tabs (which |
| 236 | * we will put into tabx (for ntabs) and tab2x (for n2tabs)). |
| 237 | */ |
| 238 | |
| 239 | ntabs = (deltax + srcx % tty->Wcm->cm_tabwidth) / tty->Wcm->cm_tabwidth; |
| 240 | n2tabs = ntabs + 1; |
| 241 | tabx = (srcx / tty->Wcm->cm_tabwidth + ntabs) * tty->Wcm->cm_tabwidth; |
| 242 | tab2x = tabx + tty->Wcm->cm_tabwidth; |
| 243 | |
| 244 | if (tab2x >= tty->Wcm->cm_cols) /* too far (past edge) */ |
| 245 | n2tabs = 0; |
| 246 | |
| 247 | /* |
| 248 | * Now set tabcost to the cost for using ntabs, and c to the cost |
| 249 | * for using n2tabs, then pick the minimum. |
| 250 | */ |
| 251 | |
| 252 | /* cost for ntabs + cost for right motion */ |
| 253 | tabcost = ntabs ? ntabs * tty->Wcm->cc_tab + (dstx - tabx) * tty->Wcm->cc_right |
| 254 | : BIG; |
| 255 | |
| 256 | /* cost for n2tabs + cost for left motion */ |
| 257 | c = n2tabs ? n2tabs * tty->Wcm->cc_tab + (tab2x - dstx) * tty->Wcm->cc_left |
| 258 | : BIG; |
| 259 | |
| 260 | if (c < tabcost) /* then cheaper to overshoot & back up */ |
| 261 | ntabs = n2tabs, tabcost = c, tabx = tab2x; |
| 262 | |
| 263 | if (tabcost >= BIG) /* caint use tabs */ |
| 264 | goto newdelta; |
| 265 | |
| 266 | /* |
| 267 | * See if tabcost is less than just moving right |
| 268 | */ |
| 269 | |
| 270 | if (tabcost < (deltax * tty->Wcm->cc_right)) { |
| 271 | totalcost += tabcost; /* use the tabs */ |
| 272 | if (doit) |
| 273 | while (--ntabs >= 0) |
| 274 | emacs_tputs (tty, tty->Wcm->cm_tab, 1, cmputc); |
| 275 | srcx = tabx; |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * Now might as well just recompute the delta. |
| 280 | */ |
| 281 | |
| 282 | newdelta: |
| 283 | if ((deltax = dstx - srcx) == 0) |
| 284 | goto done; |
| 285 | olddelta: |
| 286 | if (deltax > 0) |
| 287 | p = tty->Wcm->cm_right, c = tty->Wcm->cc_right; |
| 288 | else |
| 289 | p = tty->Wcm->cm_left, c = tty->Wcm->cc_left, deltax = -deltax; |
| 290 | |
| 291 | dodelta: |
| 292 | if (c == BIG) { /* caint get thar from here */ |
| 293 | fail: |
| 294 | if (doit) |
| 295 | printf ("OOPS"); |
| 296 | return BIG; |
| 297 | } |
| 298 | totalcost += c * deltax; |
| 299 | if (doit) |
| 300 | do |
| 301 | emacs_tputs (tty, p, 1, cmputc); |
| 302 | while (0 < --deltax); |
| 303 | done: |
| 304 | return totalcost; |
| 305 | } |
| 306 | |
| 307 | #if 0 |
| 308 | void |
| 309 | losecursor (void) |
| 310 | { |
| 311 | curY = -1; |
| 312 | } |
| 313 | #endif |
| 314 | |
| 315 | #define USEREL 0 |
| 316 | #define USEHOME 1 |
| 317 | #define USELL 2 |
| 318 | #define USECR 3 |
| 319 | |
| 320 | void |
| 321 | cmgoto (struct tty_display_info *tty, int row, int col) |
| 322 | { |
| 323 | int homecost, |
| 324 | crcost, |
| 325 | llcost, |
| 326 | relcost, |
| 327 | directcost; |
| 328 | int use IF_LINT (= 0); |
| 329 | char *p; |
| 330 | const char *dcm; |
| 331 | |
| 332 | /* First the degenerate case */ |
| 333 | if (row == curY (tty) && col == curX (tty)) /* already there */ |
| 334 | return; |
| 335 | |
| 336 | if (curY (tty) >= 0 && curX (tty) >= 0) |
| 337 | { |
| 338 | /* We may have quick ways to go to the upper-left, bottom-left, |
| 339 | * start-of-line, or start-of-next-line. Or it might be best to |
| 340 | * start where we are. Examine the options, and pick the cheapest. |
| 341 | */ |
| 342 | |
| 343 | relcost = calccost (tty, curY (tty), curX (tty), row, col, 0); |
| 344 | use = USEREL; |
| 345 | if ((homecost = tty->Wcm->cc_home) < BIG) |
| 346 | homecost += calccost (tty, 0, 0, row, col, 0); |
| 347 | if (homecost < relcost) |
| 348 | relcost = homecost, use = USEHOME; |
| 349 | if ((llcost = tty->Wcm->cc_ll) < BIG) |
| 350 | llcost += calccost (tty, tty->Wcm->cm_rows - 1, 0, row, col, 0); |
| 351 | if (llcost < relcost) |
| 352 | relcost = llcost, use = USELL; |
| 353 | if ((crcost = tty->Wcm->cc_cr) < BIG) { |
| 354 | if (tty->Wcm->cm_autolf) |
| 355 | if (curY (tty) + 1 >= tty->Wcm->cm_rows) |
| 356 | crcost = BIG; |
| 357 | else |
| 358 | crcost += calccost (tty, curY (tty) + 1, 0, row, col, 0); |
| 359 | else |
| 360 | crcost += calccost (tty, curY (tty), 0, row, col, 0); |
| 361 | } |
| 362 | if (crcost < relcost) |
| 363 | relcost = crcost, use = USECR; |
| 364 | directcost = tty->Wcm->cc_abs, dcm = tty->Wcm->cm_abs; |
| 365 | if (row == curY (tty) && tty->Wcm->cc_habs < BIG) |
| 366 | directcost = tty->Wcm->cc_habs, dcm = tty->Wcm->cm_habs; |
| 367 | else if (col == curX (tty) && tty->Wcm->cc_vabs < BIG) |
| 368 | directcost = tty->Wcm->cc_vabs, dcm = tty->Wcm->cm_vabs; |
| 369 | } |
| 370 | else |
| 371 | { |
| 372 | directcost = 0, relcost = 100000; |
| 373 | dcm = tty->Wcm->cm_abs; |
| 374 | } |
| 375 | |
| 376 | /* |
| 377 | * In the following comparison, the = in <= is because when the costs |
| 378 | * are the same, it looks nicer (I think) to move directly there. |
| 379 | */ |
| 380 | if (directcost <= relcost) |
| 381 | { |
| 382 | /* compute REAL direct cost */ |
| 383 | cost = 0; |
| 384 | p = (dcm == tty->Wcm->cm_habs |
| 385 | ? tgoto (dcm, row, col) |
| 386 | : tgoto (dcm, col, row)); |
| 387 | emacs_tputs (tty, p, 1, evalcost); |
| 388 | if (cost <= relcost) |
| 389 | { /* really is cheaper */ |
| 390 | emacs_tputs (tty, p, 1, cmputc); |
| 391 | curY (tty) = row, curX (tty) = col; |
| 392 | return; |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | switch (use) |
| 397 | { |
| 398 | case USEHOME: |
| 399 | emacs_tputs (tty, tty->Wcm->cm_home, 1, cmputc); |
| 400 | curY (tty) = 0, curX (tty) = 0; |
| 401 | break; |
| 402 | |
| 403 | case USELL: |
| 404 | emacs_tputs (tty, tty->Wcm->cm_ll, 1, cmputc); |
| 405 | curY (tty) = tty->Wcm->cm_rows - 1, curX (tty) = 0; |
| 406 | break; |
| 407 | |
| 408 | case USECR: |
| 409 | emacs_tputs (tty, tty->Wcm->cm_cr, 1, cmputc); |
| 410 | if (tty->Wcm->cm_autolf) |
| 411 | curY (tty)++; |
| 412 | curX (tty) = 0; |
| 413 | break; |
| 414 | } |
| 415 | |
| 416 | (void) calccost (tty, curY (tty), curX (tty), row, col, 1); |
| 417 | curY (tty) = row, curX (tty) = col; |
| 418 | } |
| 419 | |
| 420 | /* Clear out all terminal info. |
| 421 | Used before copying into it the info on the actual terminal. |
| 422 | */ |
| 423 | |
| 424 | void |
| 425 | Wcm_clear (struct tty_display_info *tty) |
| 426 | { |
| 427 | memset (tty->Wcm, 0, sizeof (struct cm)); |
| 428 | UP = 0; |
| 429 | BC = 0; |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * Initialized stuff |
| 434 | * Return 0 if can do CM. |
| 435 | * Return -1 if cannot. |
| 436 | * Return -2 if size not specified. |
| 437 | */ |
| 438 | |
| 439 | int |
| 440 | Wcm_init (struct tty_display_info *tty) |
| 441 | { |
| 442 | #if 0 |
| 443 | if (tty->Wcm->cm_abs && !tty->Wcm->cm_ds) |
| 444 | return 0; |
| 445 | #endif |
| 446 | if (tty->Wcm->cm_abs) |
| 447 | return 0; |
| 448 | /* Require up and left, and, if no absolute, down and right */ |
| 449 | if (!tty->Wcm->cm_up || !tty->Wcm->cm_left) |
| 450 | return - 1; |
| 451 | if (!tty->Wcm->cm_abs && (!tty->Wcm->cm_down || !tty->Wcm->cm_right)) |
| 452 | return - 1; |
| 453 | /* Check that we know the size of the screen.... */ |
| 454 | if (tty->Wcm->cm_rows <= 0 || tty->Wcm->cm_cols <= 0) |
| 455 | return - 2; |
| 456 | return 0; |
| 457 | } |