grid.c

   1 /* $OpenBSD$ */
   2
   3 /*
   4  * Copyright (c) 2008 Nicholas Marriott <nicm@users.sourceforge.net>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/types.h>
  20
  21 #include <stdlib.h>
  22 #include <string.h>
  23
  24 #include "tmux.h"
  25
  26 /*
  27  * Grid data. This is the basic data structure that represents what is shown on
  28  * screen.
  29  *
  30  * A grid is a grid of cells (struct grid_cell). Lines are not allocated until
  31  * cells in that line are written to. The grid is split into history and
  32  * viewable data with the history starting at row (line) 0 and extending to
  33  * (hsize - 1); from hsize to hsize + (sy - 1) is the viewable data. All
  34  * functions in this file work on absolute coordinates, grid-view.c has
  35  * functions which work on the screen data.
  36  */
  37
  38 /* Default grid cell data. */
  39 const struct grid_cell grid_default_cell = { 0, 0, 8, 8, (1 << 4) | 1, " " };
  40 const struct grid_cell grid_marker_cell = { 0, 0, 8, 8, (1 << 4) | 1, "_" };
  41
  42 #define grid_put_cell(gd, px, py, gc) do {                      \
  43         memcpy(&gd->linedata[py].celldata[px],                  \
  44             gc, sizeof gd->linedata[py].celldata[px]);          \
  45 } while (0)
  46 #define grid_put_utf8(gd, px, py, gc) do {                      \
  47         memcpy(&gd->linedata[py].utf8data[px],                  \
  48             gc, sizeof gd->linedata[py].utf8data[px]);          \
  49 } while (0)
  50
  51 int     grid_check_y(struct grid *, u_int);
  52
  53 #ifdef DEBUG
  54 int
  55 grid_check_y(struct grid *gd, u_int py)
  56 {
  57         if ((py) >= (gd)->hsize + (gd)->sy)
  58                 log_fatalx("y out of range: %u", py);
  59         return (0);
  60 }
  61 #else
  62 int
  63 grid_check_y(struct grid *gd, u_int py)
  64 {
  65         if ((py) >= (gd)->hsize + (gd)->sy) {
  66                 log_debug("y out of range: %u", py);
  67                 return (-1);
  68         }
  69         return (0);
  70 }
  71 #endif
  72
  73 void    grid_reflow_join(struct grid *, u_int *, struct grid_line *, u_int);
  74 void    grid_reflow_split(struct grid *, u_int *, struct grid_line *, u_int,
  75             u_int);
  76 void    grid_reflow_move(struct grid *, u_int *, struct grid_line *);
  77 size_t  grid_string_cells_fg(const struct grid_cell *, int *);
  78 size_t  grid_string_cells_bg(const struct grid_cell *, int *);
  79 void    grid_string_cells_code(const struct grid_cell *,
  80             const struct grid_cell *, char *, size_t, int);
  81
  82 /* Create a new grid. */
  83 struct grid *
  84 grid_create(u_int sx, u_int sy, u_int hlimit)
  85 {
  86         struct grid     *gd;
  87
  88         gd = xmalloc(sizeof *gd);
  89         gd->sx = sx;
  90         gd->sy = sy;
  91
  92         gd->flags = GRID_HISTORY;
  93
  94         gd->hsize = 0;
  95         gd->hlimit = hlimit;
  96
  97         gd->linedata = xcalloc(gd->sy, sizeof *gd->linedata);
  98
  99         return (gd);
 100 }
 101
 102 /* Destroy grid. */
 103 void
 104 grid_destroy(struct grid *gd)
 105 {
 106         struct grid_line        *gl;
 107         u_int                    yy;
 108
 109         for (yy = 0; yy < gd->hsize + gd->sy; yy++) {
 110                 gl = &gd->linedata[yy];
 111                 free(gl->celldata);
 112         }
 113
 114         free(gd->linedata);
 115
 116         free(gd);
 117 }
 118
 119 /* Compare grids. */
 120 int
 121 grid_compare(struct grid *ga, struct grid *gb)
 122 {
 123         struct grid_line        *gla, *glb;
 124         struct grid_cell        *gca, *gcb;
 125         u_int                    xx, yy;
 126
 127         if (ga->sx != gb->sx || ga->sy != ga->sy)
 128                 return (1);
 129
 130         for (yy = 0; yy < ga->sy; yy++) {
 131                 gla = &ga->linedata[yy];
 132                 glb = &gb->linedata[yy];
 133                 if (gla->cellsize != glb->cellsize)
 134                         return (1);
 135                 for (xx = 0; xx < ga->sx; xx++) {
 136                         gca = &gla->celldata[xx];
 137                         gcb = &glb->celldata[xx];
 138                         if (memcmp(gca, gcb, sizeof (struct grid_cell)) != 0)
 139                                 return (1);
 140                 }
 141         }
 142
 143         return (0);
 144 }
 145
 146 /*
 147  * Collect lines from the history if at the limit. Free the top (oldest) 10%
 148  * and shift up.
 149  */
 150 void
 151 grid_collect_history(struct grid *gd)
 152 {
 153         u_int   yy;
 154
 155         GRID_DEBUG(gd, "");
 156
 157         if (gd->hsize < gd->hlimit)
 158                 return;
 159
 160         yy = gd->hlimit / 10;
 161         if (yy < 1)
 162                 yy = 1;
 163
 164         grid_move_lines(gd, 0, yy, gd->hsize + gd->sy - yy);
 165         gd->hsize -= yy;
 166 }
 167
 168 /*
 169  * Scroll the entire visible screen, moving one line into the history. Just
 170  * allocate a new line at the bottom and move the history size indicator.
 171  */
 172 void
 173 grid_scroll_history(struct grid *gd)
 174 {
 175         u_int   yy;
 176
 177         GRID_DEBUG(gd, "");
 178
 179         yy = gd->hsize + gd->sy;
 180         gd->linedata = xrealloc(gd->linedata, yy + 1, sizeof *gd->linedata);
 181         memset(&gd->linedata[yy], 0, sizeof gd->linedata[yy]);
 182
 183         gd->hsize++;
 184 }
 185
 186 /* Scroll a region up, moving the top line into the history. */
 187 void
 188 grid_scroll_history_region(struct grid *gd, u_int upper, u_int lower)
 189 {
 190         struct grid_line        *gl_history, *gl_upper, *gl_lower;
 191         u_int                    yy;
 192
 193         GRID_DEBUG(gd, "upper=%u, lower=%u", upper, lower);
 194
 195         /* Create a space for a new line. */
 196         yy = gd->hsize + gd->sy;
 197         gd->linedata = xrealloc(gd->linedata, yy + 1, sizeof *gd->linedata);
 198
 199         /* Move the entire screen down to free a space for this line. */
 200         gl_history = &gd->linedata[gd->hsize];
 201         memmove(gl_history + 1, gl_history, gd->sy * sizeof *gl_history);
 202
 203         /* Adjust the region and find its start and end. */
 204         upper++;
 205         gl_upper = &gd->linedata[upper];
 206         lower++;
 207         gl_lower = &gd->linedata[lower];
 208
 209         /* Move the line into the history. */
 210         memcpy(gl_history, gl_upper, sizeof *gl_history);
 211
 212         /* Then move the region up and clear the bottom line. */
 213         memmove(gl_upper, gl_upper + 1, (lower - upper) * sizeof *gl_upper);
 214         memset(gl_lower, 0, sizeof *gl_lower);
 215
 216         /* Move the history offset down over the line. */
 217         gd->hsize++;
 218 }
 219
 220 /* Expand line to fit to cell. */
 221 void
 222 grid_expand_line(struct grid *gd, u_int py, u_int sx)
 223 {
 224         struct grid_line        *gl;
 225         u_int                    xx;
 226
 227         gl = &gd->linedata[py];
 228         if (sx <= gl->cellsize)
 229                 return;
 230
 231         gl->celldata = xrealloc(gl->celldata, sx, sizeof *gl->celldata);
 232         for (xx = gl->cellsize; xx < sx; xx++)
 233                 grid_put_cell(gd, xx, py, &grid_default_cell);
 234         gl->cellsize = sx;
 235 }
 236
 237 /* Peek at grid line. */
 238 const struct grid_line *
 239 grid_peek_line(struct grid *gd, u_int py)
 240 {
 241         if (grid_check_y(gd, py) != 0)
 242                 return (NULL);
 243         return (&gd->linedata[py]);
 244 }
 245
 246 /* Get cell for reading. */
 247 const struct grid_cell *
 248 grid_peek_cell(struct grid *gd, u_int px, u_int py)
 249 {
 250         if (grid_check_y(gd, py) != 0)
 251                 return (&grid_default_cell);
 252
 253         if (px >= gd->linedata[py].cellsize)
 254                 return (&grid_default_cell);
 255         return (&gd->linedata[py].celldata[px]);
 256 }
 257
 258 /* Get cell at relative position (for writing). */
 259 struct grid_cell *
 260 grid_get_cell(struct grid *gd, u_int px, u_int py)
 261 {
 262         if (grid_check_y(gd, py) != 0)
 263                 return (NULL);
 264
 265         grid_expand_line(gd, py, px + 1);
 266         return (&gd->linedata[py].celldata[px]);
 267 }
 268
 269 /* Set cell at relative position. */
 270 void
 271 grid_set_cell(struct grid *gd, u_int px, u_int py, const struct grid_cell *gc)
 272 {
 273         if (grid_check_y(gd, py) != 0)
 274                 return;
 275
 276         grid_expand_line(gd, py, px + 1);
 277         grid_put_cell(gd, px, py, gc);
 278 }
 279
 280 /* Clear area. */
 281 void
 282 grid_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny)
 283 {
 284         u_int   xx, yy;
 285
 286         GRID_DEBUG(gd, "px=%u, py=%u, nx=%u, ny=%u", px, py, nx, ny);
 287
 288         if (nx == 0 || ny == 0)
 289                 return;
 290
 291         if (px == 0 && nx == gd->sx) {
 292                 grid_clear_lines(gd, py, ny);
 293                 return;
 294         }
 295
 296         if (grid_check_y(gd, py) != 0)
 297                 return;
 298         if (grid_check_y(gd, py + ny - 1) != 0)
 299                 return;
 300
 301         for (yy = py; yy < py + ny; yy++) {
 302                 if (px >= gd->linedata[yy].cellsize)
 303                         continue;
 304                 if (px + nx >= gd->linedata[yy].cellsize) {
 305                         gd->linedata[yy].cellsize = px;
 306                         continue;
 307                 }
 308                 for (xx = px; xx < px + nx; xx++) {
 309                         if (xx >= gd->linedata[yy].cellsize)
 310                                 break;
 311                         grid_put_cell(gd, xx, yy, &grid_default_cell);
 312                 }
 313         }
 314 }
 315
 316 /* Clear lines. This just frees and truncates the lines. */
 317 void
 318 grid_clear_lines(struct grid *gd, u_int py, u_int ny)
 319 {
 320         struct grid_line        *gl;
 321         u_int                    yy;
 322
 323         GRID_DEBUG(gd, "py=%u, ny=%u", py, ny);
 324
 325         if (ny == 0)
 326                 return;
 327
 328         if (grid_check_y(gd, py) != 0)
 329                 return;
 330         if (grid_check_y(gd, py + ny - 1) != 0)
 331                 return;
 332
 333         for (yy = py; yy < py + ny; yy++) {
 334                 gl = &gd->linedata[yy];
 335                 free(gl->celldata);
 336                 memset(gl, 0, sizeof *gl);
 337         }
 338 }
 339
 340 /* Move a group of lines. */
 341 void
 342 grid_move_lines(struct grid *gd, u_int dy, u_int py, u_int ny)
 343 {
 344         u_int   yy;
 345
 346         GRID_DEBUG(gd, "dy=%u, py=%u, ny=%u", dy, py, ny);
 347
 348         if (ny == 0 || py == dy)
 349                 return;
 350
 351         if (grid_check_y(gd, py) != 0)
 352                 return;
 353         if (grid_check_y(gd, py + ny - 1) != 0)
 354                 return;
 355         if (grid_check_y(gd, dy) != 0)
 356                 return;
 357         if (grid_check_y(gd, dy + ny - 1) != 0)
 358                 return;
 359
 360         /* Free any lines which are being replaced. */
 361         for (yy = dy; yy < dy + ny; yy++) {
 362                 if (yy >= py && yy < py + ny)
 363                         continue;
 364                 grid_clear_lines(gd, yy, 1);
 365         }
 366
 367         memmove(
 368             &gd->linedata[dy], &gd->linedata[py], ny * (sizeof *gd->linedata));
 369
 370         /* Wipe any lines that have been moved (without freeing them). */
 371         for (yy = py; yy < py + ny; yy++) {
 372                 if (yy >= dy && yy < dy + ny)
 373                         continue;
 374                 memset(&gd->linedata[yy], 0, sizeof gd->linedata[yy]);
 375         }
 376 }
 377
 378 /* Move a group of cells. */
 379 void
 380 grid_move_cells(struct grid *gd, u_int dx, u_int px, u_int py, u_int nx)
 381 {
 382         struct grid_line        *gl;
 383         u_int                    xx;
 384
 385         GRID_DEBUG(gd, "dx=%u, px=%u, py=%u, nx=%u", dx, px, py, nx);
 386
 387         if (nx == 0 || px == dx)
 388                 return;
 389
 390         if (grid_check_y(gd, py) != 0)
 391                 return;
 392         gl = &gd->linedata[py];
 393
 394         grid_expand_line(gd, py, px + nx);
 395         grid_expand_line(gd, py, dx + nx);
 396         memmove(
 397             &gl->celldata[dx], &gl->celldata[px], nx * sizeof *gl->celldata);
 398
 399         /* Wipe any cells that have been moved. */
 400         for (xx = px; xx < px + nx; xx++) {
 401                 if (xx >= dx && xx < dx + nx)
 402                         continue;
 403                 grid_put_cell(gd, xx, py, &grid_default_cell);
 404         }
 405 }
 406
 407 /* Get ANSI foreground sequence. */
 408 size_t
 409 grid_string_cells_fg(const struct grid_cell *gc, int *values)
 410 {
 411         size_t  n;
 412
 413         n = 0;
 414         if (gc->flags & GRID_FLAG_FG256) {
 415                 values[n++] = 38;
 416                 values[n++] = 5;
 417                 values[n++] = gc->fg;
 418         } else {
 419                 switch (gc->fg) {
 420                         case 0:
 421                         case 1:
 422                         case 2:
 423                         case 3:
 424                         case 4:
 425                         case 5:
 426                         case 6:
 427                         case 7:
 428                                 values[n++] = gc->fg + 30;
 429                                 break;
 430                         case 8:
 431                                 values[n++] = 39;
 432                                 break;
 433                         case 90:
 434                         case 91:
 435                         case 92:
 436                         case 93:
 437                         case 94:
 438                         case 95:
 439                         case 96:
 440                         case 97:
 441                                 values[n++] = gc->fg;
 442                                 break;
 443                 }
 444         }
 445         return (n);
 446 }
 447
 448 /* Get ANSI background sequence. */
 449 size_t
 450 grid_string_cells_bg(const struct grid_cell *gc, int *values)
 451 {
 452         size_t  n;
 453
 454         n = 0;
 455         if (gc->flags & GRID_FLAG_BG256) {
 456                 values[n++] = 48;
 457                 values[n++] = 5;
 458                 values[n++] = gc->bg;
 459         } else {
 460                 switch (gc->bg) {
 461                 case 0:
 462                 case 1:
 463                 case 2:
 464                 case 3:
 465                 case 4:
 466                 case 5:
 467                 case 6:
 468                 case 7:
 469                         values[n++] = gc->bg + 40;
 470                         break;
 471                 case 8:
 472                         values[n++] = 49;
 473                         break;
 474                 case 100:
 475                 case 101:
 476                 case 102:
 477                 case 103:
 478                 case 104:
 479                         case 105:
 480                 case 106:
 481                 case 107:
 482                         values[n++] = gc->bg - 10;
 483                         break;
 484                 }
 485         }
 486         return (n);
 487 }
 488
 489 /*
 490  * Returns ANSI code to set particular attributes (colour, bold and so on)
 491  * given a current state. The output buffer must be able to hold at least 57
 492  * bytes.
 493  */
 494 void
 495 grid_string_cells_code(const struct grid_cell *lastgc,
 496     const struct grid_cell *gc, char *buf, size_t len, int escape_c0)
 497 {
 498         int     oldc[16], newc[16], s[32];
 499         size_t  noldc, nnewc, n, i;
 500         u_int   attr = gc->attr;
 501         u_int   lastattr = lastgc->attr;
 502         char    tmp[64];
 503
 504         struct {
 505                 u_int   mask;
 506                 u_int   code;
 507         } attrs[] = {
 508                 { GRID_ATTR_BRIGHT, 1 },
 509                 { GRID_ATTR_DIM, 2 },
 510                 { GRID_ATTR_ITALICS, 3 },
 511                 { GRID_ATTR_UNDERSCORE, 4 },
 512                 { GRID_ATTR_BLINK, 5 },
 513                 { GRID_ATTR_REVERSE, 7 },
 514                 { GRID_ATTR_HIDDEN, 8 }
 515         };
 516         n = 0;
 517
 518         /* If any attribute is removed, begin with 0. */
 519         for (i = 0; i < nitems(attrs); i++) {
 520                 if (!(attr & attrs[i].mask) && (lastattr & attrs[i].mask)) {
 521                         s[n++] = 0;
 522                         lastattr &= GRID_ATTR_CHARSET;
 523                         break;
 524                 }
 525         }
 526         /* For each attribute that is newly set, add its code. */
 527         for (i = 0; i < nitems(attrs); i++) {
 528                 if ((attr & attrs[i].mask) && !(lastattr & attrs[i].mask))
 529                         s[n++] = attrs[i].code;
 530         }
 531
 532         /* If the foreground c changed, append its parameters. */
 533         nnewc = grid_string_cells_fg(gc, newc);
 534         noldc = grid_string_cells_fg(lastgc, oldc);
 535         if (nnewc != noldc ||
 536             memcmp(newc,oldc, nnewc * sizeof newc[0]) != 0) {
 537                 for (i = 0; i < nnewc; i++)
 538                         s[n++] = newc[i];
 539         }
 540
 541         /* If the background c changed, append its parameters. */
 542         nnewc = grid_string_cells_bg(gc, newc);
 543         noldc = grid_string_cells_bg(lastgc, oldc);
 544         if (nnewc != noldc ||
 545             memcmp(newc, oldc, nnewc * sizeof newc[0]) != 0) {
 546                 for (i = 0; i < nnewc; i++)
 547                         s[n++] = newc[i];
 548         }
 549
 550         /* If there are any parameters, append an SGR code. */
 551         *buf = '\0';
 552         if (n > 0) {
 553                 if (escape_c0)
 554                         strlcat(buf, "\\033[", len);
 555                 else
 556                         strlcat(buf, "\033[", len);
 557                 for (i = 0; i < n; i++) {
 558                         if (i + 1 < n)
 559                                 xsnprintf(tmp, sizeof tmp, "%d;", s[i]);
 560                         else
 561                                 xsnprintf(tmp, sizeof tmp, "%d", s[i]);
 562                         strlcat(buf, tmp, len);
 563                 }
 564                 strlcat(buf, "m", len);
 565         }
 566
 567         /* Append shift in/shift out if needed. */
 568         if ((attr & GRID_ATTR_CHARSET) && !(lastattr & GRID_ATTR_CHARSET)) {
 569                 if (escape_c0)
 570                         strlcat(buf, "\\016", len);  /* SO */
 571                 else
 572                         strlcat(buf, "\016", len);  /* SO */
 573         }
 574         if (!(attr & GRID_ATTR_CHARSET) && (lastattr & GRID_ATTR_CHARSET)) {
 575                 if (escape_c0)
 576                         strlcat(buf, "\\017", len);  /* SI */
 577                 else
 578                         strlcat(buf, "\017", len);  /* SI */
 579         }
 580 }
 581
 582 /* Convert cells into a string. */
 583 char *
 584 grid_string_cells(struct grid *gd, u_int px, u_int py, u_int nx,
 585     struct grid_cell **lastgc, int with_codes, int escape_c0, int trim)
 586 {
 587         const struct grid_cell  *gc;
 588         static struct grid_cell  lastgc1;
 589         struct utf8_data         ud;
 590         const char*              data;
 591         char                    *buf, code[128];
 592         size_t                   len, off, size, codelen;
 593         u_int                    xx;
 594         const struct grid_line  *gl;
 595
 596         GRID_DEBUG(gd, "px=%u, py=%u, nx=%u", px, py, nx);
 597
 598         if (lastgc != NULL && *lastgc == NULL) {
 599                 memcpy(&lastgc1, &grid_default_cell, sizeof lastgc1);
 600                 *lastgc = &lastgc1;
 601         }
 602
 603         len = 128;
 604         buf = xmalloc(len);
 605         off = 0;
 606
 607         gl = grid_peek_line(gd, py);
 608         for (xx = px; xx < px + nx; xx++) {
 609                 if (gl == NULL || xx >= gl->cellsize)
 610                         break;
 611                 gc = &gl->celldata[xx];
 612                 if (gc->flags & GRID_FLAG_PADDING)
 613                         continue;
 614                 grid_cell_get(gc, &ud);
 615
 616                 if (with_codes) {
 617                         grid_string_cells_code(*lastgc, gc, code, sizeof code,
 618                             escape_c0);
 619                         codelen = strlen(code);
 620                         memcpy(*lastgc, gc, sizeof *gc);
 621                 } else
 622                         codelen = 0;
 623
 624                 data = ud.data;
 625                 size = ud.size;
 626                 if (escape_c0 && size == 1 && *data == '\\') {
 627                         data = "\\\\";
 628                         size = 2;
 629                 }
 630
 631                 while (len < off + size + codelen + 1) {
 632                         buf = xrealloc(buf, 2, len);
 633                         len *= 2;
 634                 }
 635
 636                 if (codelen != 0) {
 637                         memcpy(buf + off, code, codelen);
 638                         off += codelen;
 639                 }
 640                 memcpy(buf + off, data, size);
 641                 off += size;
 642         }
 643
 644         if (trim) {
 645                 while (off > 0 && buf[off - 1] == ' ')
 646                         off--;
 647         }
 648         buf[off] = '\0';
 649
 650         return (buf);
 651 }
 652
 653 /*
 654  * Duplicate a set of lines between two grids. If there aren't enough lines in
 655  * either source or destination, the number of lines is limited to the number
 656  * available.
 657  */
 658 void
 659 grid_duplicate_lines(struct grid *dst, u_int dy, struct grid *src, u_int sy,
 660     u_int ny)
 661 {
 662         struct grid_line        *dstl, *srcl;
 663         u_int                    yy;
 664
 665         GRID_DEBUG(src, "dy=%u, sy=%u, ny=%u", dy, sy, ny);
 666
 667         if (dy + ny > dst->hsize + dst->sy)
 668                 ny = dst->hsize + dst->sy - dy;
 669         if (sy + ny > src->hsize + src->sy)
 670                 ny = src->hsize + src->sy - sy;
 671         grid_clear_lines(dst, dy, ny);
 672
 673         for (yy = 0; yy < ny; yy++) {
 674                 srcl = &src->linedata[sy];
 675                 dstl = &dst->linedata[dy];
 676
 677                 memcpy(dstl, srcl, sizeof *dstl);
 678                 if (srcl->cellsize != 0) {
 679                         dstl->celldata = xcalloc(
 680                             srcl->cellsize, sizeof *dstl->celldata);
 681                         memcpy(dstl->celldata, srcl->celldata,
 682                             srcl->cellsize * sizeof *dstl->celldata);
 683                 }
 684
 685                 sy++;
 686                 dy++;
 687         }
 688 }
 689
 690 /* Join line data. */
 691 void
 692 grid_reflow_join(struct grid *dst, u_int *py, struct grid_line *src_gl,
 693     u_int new_x)
 694 {
 695         struct grid_line        *dst_gl = &dst->linedata[(*py) - 1];
 696         u_int                    left, to_copy, ox, nx;
 697
 698         /* How much is left on the old line? */
 699         left = new_x - dst_gl->cellsize;
 700
 701         /* Work out how much to append. */
 702         to_copy = src_gl->cellsize;
 703         if (to_copy > left)
 704                 to_copy = left;
 705         ox = dst_gl->cellsize;
 706         nx = ox + to_copy;
 707
 708         /* Resize the destination line. */
 709         dst_gl->celldata = xrealloc(dst_gl->celldata, nx,
 710             sizeof *dst_gl->celldata);
 711         dst_gl->cellsize = nx;
 712
 713         /* Append as much as possible. */
 714         memcpy(&dst_gl->celldata[ox], &src_gl->celldata[0],
 715             to_copy * sizeof src_gl->celldata[0]);
 716
 717         /* If there is any left in the source, split it. */
 718         if (src_gl->cellsize > to_copy) {
 719                 dst_gl->flags |= GRID_LINE_WRAPPED;
 720
 721                 src_gl->cellsize -= to_copy;
 722                 grid_reflow_split(dst, py, src_gl, new_x, to_copy);
 723         }
 724 }
 725
 726 /* Split line data. */
 727 void
 728 grid_reflow_split(struct grid *dst, u_int *py, struct grid_line *src_gl,
 729     u_int new_x, u_int offset)
 730 {
 731         struct grid_line        *dst_gl = NULL;
 732         u_int                    to_copy;
 733
 734         /* Loop and copy sections of the source line. */
 735         while (src_gl->cellsize > 0) {
 736                 /* Create new line. */
 737                 if (*py >= dst->hsize + dst->sy)
 738                         grid_scroll_history(dst);
 739                 dst_gl = &dst->linedata[*py];
 740                 (*py)++;
 741
 742                 /* How much should we copy? */
 743                 to_copy = new_x;
 744                 if (to_copy > src_gl->cellsize)
 745                         to_copy = src_gl->cellsize;
 746
 747                 /* Expand destination line. */
 748                 dst_gl->celldata = xmalloc(to_copy * sizeof *dst_gl->celldata);
 749                 dst_gl->cellsize = to_copy;
 750                 dst_gl->flags |= GRID_LINE_WRAPPED;
 751
 752                 /* Copy the data. */
 753                 memcpy (&dst_gl->celldata[0], &src_gl->celldata[offset],
 754                     to_copy * sizeof dst_gl->celldata[0]);
 755
 756                 /* Move offset and reduce old line size. */
 757                 offset += to_copy;
 758                 src_gl->cellsize -= to_copy;
 759         }
 760
 761         /* Last line is not wrapped. */
 762         if (dst_gl != NULL)
 763                 dst_gl->flags &= ~GRID_LINE_WRAPPED;
 764 }
 765
 766 /* Move line data. */
 767 void
 768 grid_reflow_move(struct grid *dst, u_int *py, struct grid_line *src_gl)
 769 {
 770         struct grid_line        *dst_gl;
 771
 772         /* Create new line. */
 773         if (*py >= dst->hsize + dst->sy)
 774                 grid_scroll_history(dst);
 775         dst_gl = &dst->linedata[*py];
 776         (*py)++;
 777
 778         /* Copy the old line. */
 779         memcpy(dst_gl, src_gl, sizeof *dst_gl);
 780         dst_gl->flags &= ~GRID_LINE_WRAPPED;
 781
 782         /* Clear old line. */
 783         src_gl->celldata = NULL;
 784 }
 785
 786 /*
 787  * Reflow lines from src grid into dst grid of width new_x. Returns number of
 788  * lines fewer in the visible area. The source grid is destroyed.
 789  */
 790 u_int
 791 grid_reflow(struct grid *dst, struct grid *src, u_int new_x)
 792 {
 793         u_int                    py, sy, line;
 794         int                      previous_wrapped;
 795         struct grid_line        *src_gl;
 796
 797         py = 0;
 798         sy = src->sy;
 799
 800         previous_wrapped = 0;
 801         for (line = 0; line < sy + src->hsize; line++) {
 802                 src_gl = src->linedata + line;
 803                 if (!previous_wrapped) {
 804                         /* Wasn't wrapped. If smaller, move to destination. */
 805                         if (src_gl->cellsize <= new_x)
 806                                 grid_reflow_move(dst, &py, src_gl);
 807                         else
 808                                 grid_reflow_split(dst, &py, src_gl, new_x, 0);
 809                 } else {
 810                         /* Previous was wrapped. Try to join. */
 811                         grid_reflow_join(dst, &py, src_gl, new_x);
 812                 }
 813                 previous_wrapped = src_gl->flags & GRID_LINE_WRAPPED;
 814         }
 815
 816         grid_destroy(src);
 817
 818         if (py > sy)
 819                 return (0);
 820         return (sy - py);
 821 }