1/* Cursor motion subroutines for GNU Emacs. 2 Copyright (C) 1985, 1995, 2001, 2002, 2003, 2004, 3 2005, 2006, 2007 Free Software Foundation, Inc. 4 based primarily on public domain code written by Chris Torek 5 6This file is part of GNU Emacs. 7 8GNU Emacs is free software; you can redistribute it and/or modify 9it under the terms of the GNU General Public License as published by 10the Free Software Foundation; either version 2, or (at your option) 11any later version. 12 13GNU Emacs is distributed in the hope that it will be useful, 14but WITHOUT ANY WARRANTY; without even the implied warranty of 15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16GNU General Public License for more details. 17 18You should have received a copy of the GNU General Public License 19along with GNU Emacs; see the file COPYING. If not, write to 20the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 21Boston, MA 02110-1301, USA. */ 22 23 24#include <config.h> 25#include <stdio.h> 26#include "cm.h" 27#include "termhooks.h" 28 29/* For now, don't try to include termcap.h. On some systems, 30 configure finds a non-standard termcap.h that the main build 31 won't find. */ 32 33#if defined HAVE_TERMCAP_H && 0 34#include <termcap.h> 35#else 36extern void tputs P_ ((const char *, int, int (*)(int))); 37extern char *tgoto P_ ((const char *, int, int)); 38#endif 39 40#define BIG 9999 /* 9999 good on VAXen. For 16 bit machines 41 use about 2000.... */ 42 43extern char *BC, *UP; 44 45int cost; /* sums up costs */ 46 47/* ARGSUSED */ 48int 49evalcost (c) 50 char c; 51{ 52 cost++; 53 return c; 54} 55 56int 57cmputc (c) 58 char c; 59{ 60 if (termscript) 61 fputc (c & 0177, termscript); 62 putchar (c & 0177); 63 return c; 64} 65 66/* NEXT TWO ARE DONE WITH MACROS */ 67#if 0 68/* 69 * Assume the cursor is at row row, column col. Normally used only after 70 * clearing the screen, when the cursor is at (0, 0), but what the heck, 71 * let's let the guy put it anywhere. 72 */ 73 74static 75at (row, col) { 76 curY = row; 77 curX = col; 78} 79 80/* 81 * Add n columns to the current cursor position. 82 */ 83 84static 85addcol (n) { 86 curX += n; 87 88 /* 89 * If cursor hit edge of screen, what happened? 90 * N.B.: DO NOT!! write past edge of screen. If you do, you 91 * deserve what you get. Furthermore, on terminals with 92 * autowrap (but not magicwrap), don't write in the last column 93 * of the last line. 94 */ 95 96 if (curX == Wcm.cm_cols) { 97 /* 98 * Well, if magicwrap, still there, past the edge of the 99 * screen (!). If autowrap, on the col 0 of the next line. 100 * Otherwise on last column. 101 */ 102 103 if (Wcm.cm_magicwrap) 104 ; /* "limbo" */ 105 else if (Wcm.cm_autowrap) { 106 curX = 0; 107 curY++; /* Beware end of screen! */ 108 } 109 else 110 curX--; 111 } 112} 113#endif 114 115/* 116 * Terminals with magicwrap (xn) don't all behave identically. 117 * The VT100 leaves the cursor in the last column but will wrap before 118 * printing the next character. I hear that the Concept terminal does 119 * the wrap immediately but ignores the next newline it sees. And some 120 * terminals just have buggy firmware, and think that the cursor is still 121 * in limbo if we use direct cursor addressing from the phantom column. 122 * The only guaranteed safe thing to do is to emit a CRLF immediately 123 * after we reach the last column; this takes us to a known state. 124 */ 125void 126cmcheckmagic () 127{ 128 if (curX == FrameCols) 129 { 130 if (!MagicWrap || curY >= FrameRows - 1) 131 abort (); 132 if (termscript) 133 putc ('\r', termscript); 134 putchar ('\r'); 135 if (termscript) 136 putc ('\n', termscript); 137 putchar ('\n'); 138 curX = 0; 139 curY++; 140 } 141} 142 143 144/* 145 * (Re)Initialize the cost factors, given the output speed of the terminal 146 * in the variable ospeed. (Note: this holds B300, B9600, etc -- ie stuff 147 * out of <sgtty.h>.) 148 */ 149 150void 151cmcostinit () 152{ 153 char *p; 154 155#define COST(x,e) (x ? (cost = 0, tputs (x, 1, e), cost) : BIG) 156#define CMCOST(x,e) ((x == 0) ? BIG : (p = tgoto(x, 0, 0), COST(p ,e))) 157 158 Wcm.cc_up = COST (Wcm.cm_up, evalcost); 159 Wcm.cc_down = COST (Wcm.cm_down, evalcost); 160 Wcm.cc_left = COST (Wcm.cm_left, evalcost); 161 Wcm.cc_right = COST (Wcm.cm_right, evalcost); 162 Wcm.cc_home = COST (Wcm.cm_home, evalcost); 163 Wcm.cc_cr = COST (Wcm.cm_cr, evalcost); 164 Wcm.cc_ll = COST (Wcm.cm_ll, evalcost); 165 Wcm.cc_tab = Wcm.cm_tabwidth ? COST (Wcm.cm_tab, evalcost) : BIG; 166 167 /* 168 * These last three are actually minimum costs. When (if) they are 169 * candidates for the least-cost motion, the real cost is computed. 170 * (Note that "0" is the assumed to generate the minimum cost. 171 * While this is not necessarily true, I have yet to see a terminal 172 * for which is not; all the terminals that have variable-cost 173 * cursor motion seem to take straight numeric values. --ACT) 174 */ 175 176 Wcm.cc_abs = CMCOST (Wcm.cm_abs, evalcost); 177 Wcm.cc_habs = CMCOST (Wcm.cm_habs, evalcost); 178 Wcm.cc_vabs = CMCOST (Wcm.cm_vabs, evalcost); 179 180#undef CMCOST 181#undef COST 182} 183 184/* 185 * Calculate the cost to move from (srcy, srcx) to (dsty, dstx) using 186 * up and down, and left and right, motions, and tabs. If doit is set 187 * actually perform the motion. 188 */ 189 190static int 191calccost (srcy, srcx, dsty, dstx, doit) 192 int srcy, srcx, dsty, dstx, doit; 193{ 194 register int deltay, 195 deltax, 196 c, 197 totalcost; 198 int ntabs, 199 n2tabs, 200 tabx, 201 tab2x, 202 tabcost; 203 register char *p; 204 205 /* If have just wrapped on a terminal with xn, 206 don't believe the cursor position: give up here 207 and force use of absolute positioning. */ 208 209 if (curX == Wcm.cm_cols) 210 goto fail; 211 212 totalcost = 0; 213 if ((deltay = dsty - srcy) == 0) 214 goto x; 215 if (deltay < 0) 216 p = Wcm.cm_up, c = Wcm.cc_up, deltay = -deltay; 217 else 218 p = Wcm.cm_down, c = Wcm.cc_down; 219 if (c == BIG) { /* caint get thar from here */ 220 if (doit) 221 printf ("OOPS"); 222 return c; 223 } 224 totalcost = c * deltay; 225 if (doit) 226 while (--deltay >= 0) 227 tputs (p, 1, cmputc); 228x: 229 if ((deltax = dstx - srcx) == 0) 230 goto done; 231 if (deltax < 0) { 232 p = Wcm.cm_left, c = Wcm.cc_left, deltax = -deltax; 233 goto dodelta; /* skip all the tab junk */ 234 } 235 /* Tabs (the toughie) */ 236 if (Wcm.cc_tab >= BIG || !Wcm.cm_usetabs) 237 goto olddelta; /* forget it! */ 238 239 /* 240 * ntabs is # tabs towards but not past dstx; n2tabs is one more 241 * (ie past dstx), but this is only valid if that is not past the 242 * right edge of the screen. We can check that at the same time 243 * as we figure out where we would be if we use the tabs (which 244 * we will put into tabx (for ntabs) and tab2x (for n2tabs)). 245 */ 246 247 ntabs = (deltax + srcx % Wcm.cm_tabwidth) / Wcm.cm_tabwidth; 248 n2tabs = ntabs + 1; 249 tabx = (srcx / Wcm.cm_tabwidth + ntabs) * Wcm.cm_tabwidth; 250 tab2x = tabx + Wcm.cm_tabwidth; 251 252 if (tab2x >= Wcm.cm_cols) /* too far (past edge) */ 253 n2tabs = 0; 254 255 /* 256 * Now set tabcost to the cost for using ntabs, and c to the cost 257 * for using n2tabs, then pick the minimum. 258 */ 259 260 /* cost for ntabs + cost for right motion */ 261 tabcost = ntabs ? ntabs * Wcm.cc_tab + (dstx - tabx) * Wcm.cc_right 262 : BIG; 263 264 /* cost for n2tabs + cost for left motion */ 265 c = n2tabs ? n2tabs * Wcm.cc_tab + (tab2x - dstx) * Wcm.cc_left 266 : BIG; 267 268 if (c < tabcost) /* then cheaper to overshoot & back up */ 269 ntabs = n2tabs, tabcost = c, tabx = tab2x; 270 271 if (tabcost >= BIG) /* caint use tabs */ 272 goto newdelta; 273 274 /* 275 * See if tabcost is less than just moving right 276 */ 277 278 if (tabcost < (deltax * Wcm.cc_right)) { 279 totalcost += tabcost; /* use the tabs */ 280 if (doit) 281 while (--ntabs >= 0) 282 tputs (Wcm.cm_tab, 1, cmputc); 283 srcx = tabx; 284 } 285 286 /* 287 * Now might as well just recompute the delta. 288 */ 289 290newdelta: 291 if ((deltax = dstx - srcx) == 0) 292 goto done; 293olddelta: 294 if (deltax > 0) 295 p = Wcm.cm_right, c = Wcm.cc_right; 296 else 297 p = Wcm.cm_left, c = Wcm.cc_left, deltax = -deltax; 298 299dodelta: 300 if (c == BIG) { /* caint get thar from here */ 301fail: 302 if (doit) 303 printf ("OOPS"); 304 return BIG; 305 } 306 totalcost += c * deltax; 307 if (doit) 308 while (--deltax >= 0) 309 tputs (p, 1, cmputc); 310done: 311 return totalcost; 312} 313 314#if 0 315losecursor () 316{ 317 curY = -1; 318} 319#endif 320 321#define USEREL 0 322#define USEHOME 1 323#define USELL 2 324#define USECR 3 325 326void 327cmgoto (row, col) 328 int row, col; 329{ 330 int homecost, 331 crcost, 332 llcost, 333 relcost, 334 directcost; 335 int use; 336 char *p, 337 *dcm; 338 339 /* First the degenerate case */ 340 if (row == curY && col == curX) /* already there */ 341 return; 342 343 if (curY >= 0 && curX >= 0) 344 { 345 /* We may have quick ways to go to the upper-left, bottom-left, 346 * start-of-line, or start-of-next-line. Or it might be best to 347 * start where we are. Examine the options, and pick the cheapest. 348 */ 349 350 relcost = calccost (curY, curX, row, col, 0); 351 use = USEREL; 352 if ((homecost = Wcm.cc_home) < BIG) 353 homecost += calccost (0, 0, row, col, 0); 354 if (homecost < relcost) 355 relcost = homecost, use = USEHOME; 356 if ((llcost = Wcm.cc_ll) < BIG) 357 llcost += calccost (Wcm.cm_rows - 1, 0, row, col, 0); 358 if (llcost < relcost) 359 relcost = llcost, use = USELL; 360 if ((crcost = Wcm.cc_cr) < BIG) { 361 if (Wcm.cm_autolf) 362 if (curY + 1 >= Wcm.cm_rows) 363 crcost = BIG; 364 else 365 crcost += calccost (curY + 1, 0, row, col, 0); 366 else 367 crcost += calccost (curY, 0, row, col, 0); 368 } 369 if (crcost < relcost) 370 relcost = crcost, use = USECR; 371 directcost = Wcm.cc_abs, dcm = Wcm.cm_abs; 372 if (row == curY && Wcm.cc_habs < BIG) 373 directcost = Wcm.cc_habs, dcm = Wcm.cm_habs; 374 else if (col == curX && Wcm.cc_vabs < BIG) 375 directcost = Wcm.cc_vabs, dcm = Wcm.cm_vabs; 376 } 377 else 378 { 379 directcost = 0, relcost = 100000; 380 dcm = Wcm.cm_abs; 381 } 382 383 /* 384 * In the following comparison, the = in <= is because when the costs 385 * are the same, it looks nicer (I think) to move directly there. 386 */ 387 if (directcost <= relcost) 388 { 389 /* compute REAL direct cost */ 390 cost = 0; 391 p = dcm == Wcm.cm_habs ? tgoto (dcm, row, col) : 392 tgoto (dcm, col, row); 393 tputs (p, 1, evalcost); 394 if (cost <= relcost) 395 { /* really is cheaper */ 396 tputs (p, 1, cmputc); 397 curY = row, curX = col; 398 return; 399 } 400 } 401 402 switch (use) 403 { 404 case USEHOME: 405 tputs (Wcm.cm_home, 1, cmputc); 406 curY = 0, curX = 0; 407 break; 408 409 case USELL: 410 tputs (Wcm.cm_ll, 1, cmputc); 411 curY = Wcm.cm_rows - 1, curX = 0; 412 break; 413 414 case USECR: 415 tputs (Wcm.cm_cr, 1, cmputc); 416 if (Wcm.cm_autolf) 417 curY++; 418 curX = 0; 419 break; 420 } 421 422 (void) calccost (curY, curX, row, col, 1); 423 curY = row, curX = col; 424} 425 426/* Clear out all terminal info. 427 Used before copying into it the info on the actual terminal. 428 */ 429 430void 431Wcm_clear () 432{ 433 bzero (&Wcm, sizeof Wcm); 434 UP = 0; 435 BC = 0; 436} 437 438/* 439 * Initialized stuff 440 * Return 0 if can do CM. 441 * Return -1 if cannot. 442 * Return -2 if size not specified. 443 */ 444 445int 446Wcm_init () 447{ 448#if 0 449 if (Wcm.cm_abs && !Wcm.cm_ds) 450 return 0; 451#endif 452 if (Wcm.cm_abs) 453 return 0; 454 /* Require up and left, and, if no absolute, down and right */ 455 if (!Wcm.cm_up || !Wcm.cm_left) 456 return - 1; 457 if (!Wcm.cm_abs && (!Wcm.cm_down || !Wcm.cm_right)) 458 return - 1; 459 /* Check that we know the size of the screen.... */ 460 if (Wcm.cm_rows <= 0 || Wcm.cm_cols <= 0) 461 return - 2; 462 return 0; 463} 464 465/* arch-tag: bcf64c02-00f6-44ef-94b6-c56eab5b3dc4 466 (do not change this comment) */ 467