layout.c

   1 /* $OpenBSD$ */
   2
   3 /*
   4  * Copyright (c) 2009 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
  23 #include "tmux.h"
  24
  25 /*
  26  * The window layout is a tree of cells each of which can be one of: a
  27  * left-right container for a list of cells, a top-bottom container for a list
  28  * of cells, or a container for a window pane.
  29  *
  30  * Each window has a pointer to the root of its layout tree (containing its
  31  * panes), every pane has a pointer back to the cell containing it, and each
  32  * cell a pointer to its parent cell.
  33  */
  34
  35 int     layout_resize_pane_grow(struct layout_cell *, enum layout_type, int);
  36 int     layout_resize_pane_shrink(struct layout_cell *, enum layout_type, int);
  37
  38 struct layout_cell *
  39 layout_create_cell(struct layout_cell *lcparent)
  40 {
  41         struct layout_cell      *lc;
  42
  43         lc = xmalloc(sizeof *lc);
  44         lc->type = LAYOUT_WINDOWPANE;
  45         lc->parent = lcparent;
  46
  47         TAILQ_INIT(&lc->cells);
  48
  49         lc->sx = UINT_MAX;
  50         lc->sy = UINT_MAX;
  51
  52         lc->xoff = UINT_MAX;
  53         lc->yoff = UINT_MAX;
  54
  55         lc->wp = NULL;
  56         lc->lastwp = NULL;
  57
  58         return (lc);
  59 }
  60
  61 void
  62 layout_free_cell(struct layout_cell *lc)
  63 {
  64         struct layout_cell      *lcchild;
  65
  66         switch (lc->type) {
  67         case LAYOUT_LEFTRIGHT:
  68         case LAYOUT_TOPBOTTOM:
  69                 while (!TAILQ_EMPTY(&lc->cells)) {
  70                         lcchild = TAILQ_FIRST(&lc->cells);
  71                         TAILQ_REMOVE(&lc->cells, lcchild, entry);
  72                         layout_free_cell(lcchild);
  73                 }
  74                 break;
  75         case LAYOUT_WINDOWPANE:
  76                 if (lc->wp != NULL)
  77                         lc->wp->layout_cell = NULL;
  78                 break;
  79         }
  80
  81         free(lc);
  82 }
  83
  84 void
  85 layout_print_cell(struct layout_cell *lc, const char *hdr, u_int n)
  86 {
  87         struct layout_cell      *lcchild;
  88
  89         log_debug(
  90             "%s:%*s%p type %u [parent %p] wp=%p [%u,%u %ux%u]", hdr, n, " ", lc,
  91             lc->type, lc->parent, lc->wp, lc->xoff, lc->yoff, lc->sx, lc->sy);
  92         switch (lc->type) {
  93         case LAYOUT_LEFTRIGHT:
  94         case LAYOUT_TOPBOTTOM:
  95                 TAILQ_FOREACH(lcchild, &lc->cells, entry)
  96                         layout_print_cell(lcchild, hdr, n + 1);
  97                 break;
  98         case LAYOUT_WINDOWPANE:
  99                 break;
 100         }
 101 }
 102
 103 void
 104 layout_set_size(
 105     struct layout_cell *lc, u_int sx, u_int sy, u_int xoff, u_int yoff)
 106 {
 107         lc->sx = sx;
 108         lc->sy = sy;
 109
 110         lc->xoff = xoff;
 111         lc->yoff = yoff;
 112 }
 113
 114 void
 115 layout_make_leaf(struct layout_cell *lc, struct window_pane *wp)
 116 {
 117         lc->type = LAYOUT_WINDOWPANE;
 118
 119         TAILQ_INIT(&lc->cells);
 120
 121         wp->layout_cell = lc;
 122         lc->wp = wp;
 123 }
 124
 125 void
 126 layout_make_node(struct layout_cell *lc, enum layout_type type)
 127 {
 128         if (type == LAYOUT_WINDOWPANE)
 129                 fatalx("bad layout type");
 130         lc->type = type;
 131
 132         TAILQ_INIT(&lc->cells);
 133
 134         if (lc->wp != NULL)
 135                 lc->wp->layout_cell = NULL;
 136         lc->wp = NULL;
 137 }
 138
 139 /* Fix cell offsets based on their sizes. */
 140 void
 141 layout_fix_offsets(struct layout_cell *lc)
 142 {
 143         struct layout_cell      *lcchild;
 144         u_int                    xoff, yoff;
 145
 146         if (lc->type == LAYOUT_LEFTRIGHT) {
 147                 xoff = lc->xoff;
 148                 TAILQ_FOREACH(lcchild, &lc->cells, entry) {
 149                         lcchild->xoff = xoff;
 150                         lcchild->yoff = lc->yoff;
 151                         if (lcchild->type != LAYOUT_WINDOWPANE)
 152                                 layout_fix_offsets(lcchild);
 153                         xoff += lcchild->sx + 1;
 154                 }
 155         } else {
 156                 yoff = lc->yoff;
 157                 TAILQ_FOREACH(lcchild, &lc->cells, entry) {
 158                         lcchild->xoff = lc->xoff;
 159                         lcchild->yoff = yoff;
 160                         if (lcchild->type != LAYOUT_WINDOWPANE)
 161                                 layout_fix_offsets(lcchild);
 162                         yoff += lcchild->sy + 1;
 163                 }
 164         }
 165 }
 166
 167 /* Update pane offsets and sizes based on their cells. */
 168 void
 169 layout_fix_panes(struct window *w, u_int wsx, u_int wsy)
 170 {
 171         struct window_pane      *wp;
 172         struct layout_cell      *lc;
 173         u_int                    sx, sy;
 174
 175         TAILQ_FOREACH(wp, &w->panes, entry) {
 176                 if ((lc = wp->layout_cell) == NULL)
 177                         continue;
 178                 wp->xoff = lc->xoff;
 179                 wp->yoff = lc->yoff;
 180
 181                 /*
 182                  * Layout cells are limited by the smallest size of other cells
 183                  * within the same row or column; if this isn't the case
 184                  * resizing becomes difficult.
 185                  *
 186                  * However, panes do not have to take up their entire cell, so
 187                  * they can be cropped to the window edge if the layout
 188                  * overflows and they are partly visible.
 189                  *
 190                  * This stops cells being hidden unnecessarily.
 191                  */
 192
 193                 /*
 194                  * Work out the horizontal size. If the pane is actually
 195                  * outside the window or the entire pane is already visible,
 196                  * don't crop.
 197                  */
 198                 if (lc->xoff >= wsx || lc->xoff + lc->sx < wsx)
 199                         sx = lc->sx;
 200                 else {
 201                         sx = wsx - lc->xoff;
 202                         if (sx < 1)
 203                                 sx = lc->sx;
 204                 }
 205
 206                 /*
 207                  * Similarly for the vertical size; the minimum vertical size
 208                  * is two because scroll regions cannot be one line.
 209                  */
 210                 if (lc->yoff >= wsy || lc->yoff + lc->sy < wsy)
 211                         sy = lc->sy;
 212                 else {
 213                         sy = wsy - lc->yoff;
 214                         if (sy < 2)
 215                                 sy = lc->sy;
 216                 }
 217
 218                 window_pane_resize(wp, sx, sy);
 219         }
 220 }
 221
 222 /* Count the number of available cells in a layout. */
 223 u_int
 224 layout_count_cells(struct layout_cell *lc)
 225 {
 226         struct layout_cell      *lcchild;
 227         u_int                    n;
 228
 229         switch (lc->type) {
 230         case LAYOUT_WINDOWPANE:
 231                 return (1);
 232         case LAYOUT_LEFTRIGHT:
 233         case LAYOUT_TOPBOTTOM:
 234                 n = 0;
 235                 TAILQ_FOREACH(lcchild, &lc->cells, entry)
 236                         n += layout_count_cells(lcchild);
 237                 return (n);
 238         default:
 239                 fatalx("bad layout type");
 240         }
 241 }
 242
 243 /* Calculate how much size is available to be removed from a cell. */
 244 u_int
 245 layout_resize_check(struct layout_cell *lc, enum layout_type type)
 246 {
 247         struct layout_cell      *lcchild;
 248         u_int                    available, minimum;
 249
 250         if (lc->type == LAYOUT_WINDOWPANE) {
 251                 /* Space available in this cell only. */
 252                 if (type == LAYOUT_LEFTRIGHT)
 253                         available = lc->sx;
 254                 else
 255                         available = lc->sy;
 256
 257                 if (available > PANE_MINIMUM)
 258                         available -= PANE_MINIMUM;
 259                 else
 260                         available = 0;
 261         } else if (lc->type == type) {
 262                 /* Same type: total of available space in all child cells. */
 263                 available = 0;
 264                 TAILQ_FOREACH(lcchild, &lc->cells, entry)
 265                         available += layout_resize_check(lcchild, type);
 266         } else {
 267                 /* Different type: minimum of available space in child cells. */
 268                 minimum = UINT_MAX;
 269                 TAILQ_FOREACH(lcchild, &lc->cells, entry) {
 270                         available = layout_resize_check(lcchild, type);
 271                         if (available < minimum)
 272                                 minimum = available;
 273                 }
 274                 available = minimum;
 275         }
 276
 277         return (available);
 278 }
 279
 280 /*
 281  * Adjust cell size evenly, including altering its children. This function
 282  * expects the change to have already been bounded to the space available.
 283  */
 284 void
 285 layout_resize_adjust(struct layout_cell *lc, enum layout_type type, int change)
 286 {
 287         struct layout_cell      *lcchild;
 288
 289         /* Adjust the cell size. */
 290         if (type == LAYOUT_LEFTRIGHT)
 291                 lc->sx += change;
 292         else
 293                 lc->sy += change;
 294
 295         /* If this is a leaf cell, that is all that is necessary. */
 296         if (type == LAYOUT_WINDOWPANE)
 297                 return;
 298
 299         /* Child cell runs in a different direction. */
 300         if (lc->type != type) {
 301                 TAILQ_FOREACH(lcchild, &lc->cells, entry)
 302                         layout_resize_adjust(lcchild, type, change);
 303                 return;
 304         }
 305
 306         /*
 307          * Child cell runs in the same direction. Adjust each child equally
 308          * until no further change is possible.
 309          */
 310         while (change != 0) {
 311                 TAILQ_FOREACH(lcchild, &lc->cells, entry) {
 312                         if (change == 0)
 313                                 break;
 314                         if (change > 0) {
 315                                 layout_resize_adjust(lcchild, type, 1);
 316                                 change--;
 317                                 continue;
 318                         }
 319                         if (layout_resize_check(lcchild, type) > 0) {
 320                                 layout_resize_adjust(lcchild, type, -1);
 321                                 change++;
 322                         }
 323                 }
 324         }
 325 }
 326
 327 /* Destroy a cell and redistribute the space. */
 328 void
 329 layout_destroy_cell(struct layout_cell *lc, struct layout_cell **lcroot)
 330 {
 331         struct layout_cell     *lcother, *lcparent;
 332
 333         /*
 334          * If no parent, this is the last pane so window close is imminent and
 335          * there is no need to resize anything.
 336          */
 337         lcparent = lc->parent;
 338         if (lcparent == NULL) {
 339                 layout_free_cell(lc);
 340                 *lcroot = NULL;
 341                 return;
 342         }
 343
 344         /* Merge the space into the previous or next cell. */
 345         if (lc == TAILQ_FIRST(&lcparent->cells))
 346                 lcother = TAILQ_NEXT(lc, entry);
 347         else
 348                 lcother = TAILQ_PREV(lc, layout_cells, entry);
 349         if (lcparent->type == LAYOUT_LEFTRIGHT)
 350                 layout_resize_adjust(lcother, lcparent->type, lc->sx + 1);
 351         else
 352                 layout_resize_adjust(lcother, lcparent->type, lc->sy + 1);
 353
 354         /* Remove this from the parent's list. */
 355         TAILQ_REMOVE(&lcparent->cells, lc, entry);
 356         layout_free_cell(lc);
 357
 358         /*
 359          * If the parent now has one cell, remove the parent from the tree and
 360          * replace it by that cell.
 361          */
 362         lc = TAILQ_FIRST(&lcparent->cells);
 363         if (TAILQ_NEXT(lc, entry) == NULL) {
 364                 TAILQ_REMOVE(&lcparent->cells, lc, entry);
 365
 366                 lc->parent = lcparent->parent;
 367                 if (lc->parent == NULL) {
 368                         lc->xoff = 0; lc->yoff = 0;
 369                         *lcroot = lc;
 370                 } else
 371                         TAILQ_REPLACE(&lc->parent->cells, lcparent, lc, entry);
 372
 373                 layout_free_cell(lcparent);
 374         }
 375 }
 376
 377 void
 378 layout_init(struct window *w, struct window_pane *wp)
 379 {
 380         struct layout_cell      *lc;
 381
 382         lc = w->layout_root = layout_create_cell(NULL);
 383         layout_set_size(lc, w->sx, w->sy, 0, 0);
 384         layout_make_leaf(lc, wp);
 385
 386         layout_fix_panes(w, w->sx, w->sy);
 387 }
 388
 389 void
 390 layout_free(struct window *w)
 391 {
 392         layout_free_cell(w->layout_root);
 393 }
 394
 395 /* Resize the entire layout after window resize. */
 396 void
 397 layout_resize(struct window *w, u_int sx, u_int sy)
 398 {
 399         struct layout_cell      *lc = w->layout_root;
 400         int                      xlimit, ylimit, xchange, ychange;
 401
 402         /*
 403          * Adjust horizontally. Do not attempt to reduce the layout lower than
 404          * the minimum (more than the amount returned by layout_resize_check).
 405          *
 406          * This can mean that the window size is smaller than the total layout
 407          * size: redrawing this is handled at a higher level, but it does leave
 408          * a problem with growing the window size here: if the current size is
 409          * < the minimum, growing proportionately by adding to each pane is
 410          * wrong as it would keep the layout size larger than the window size.
 411          * Instead, spread the difference between the minimum and the new size
 412          * out proportionately - this should leave the layout fitting the new
 413          * window size.
 414          */
 415         xchange = sx - w->sx;
 416         xlimit = layout_resize_check(lc, LAYOUT_LEFTRIGHT);
 417         if (xchange < 0 && xchange < -xlimit)
 418                 xchange = -xlimit;
 419         if (xlimit == 0) {
 420                 if (sx <= lc->sx)       /* lc->sx is minimum possible */
 421                         xchange = 0;
 422                 else
 423                         xchange = sx - lc->sx;
 424         }
 425         if (xchange != 0)
 426                 layout_resize_adjust(lc, LAYOUT_LEFTRIGHT, xchange);
 427
 428         /* Adjust vertically in a similar fashion. */
 429         ychange = sy - w->sy;
 430         ylimit = layout_resize_check(lc, LAYOUT_TOPBOTTOM);
 431         if (ychange < 0 && ychange < -ylimit)
 432                 ychange = -ylimit;
 433         if (ylimit == 0) {
 434                 if (sy <= lc->sy)       /* lc->sy is minimum possible */
 435                         ychange = 0;
 436                 else
 437                         ychange = sy - lc->sy;
 438         }
 439         if (ychange != 0)
 440                 layout_resize_adjust(lc, LAYOUT_TOPBOTTOM, ychange);
 441
 442         /* Fix cell offsets. */
 443         layout_fix_offsets(lc);
 444         layout_fix_panes(w, sx, sy);
 445 }
 446
 447 /* Resize a pane to an absolute size. */
 448 void
 449 layout_resize_pane_to(struct window_pane *wp, enum layout_type type,
 450     u_int new_size)
 451 {
 452         struct layout_cell     *lc, *lcparent;
 453         int                     change, size;
 454
 455         lc = wp->layout_cell;
 456
 457         /* Find next parent of the same type. */
 458         lcparent = lc->parent;
 459         while (lcparent != NULL && lcparent->type != type) {
 460                 lc = lcparent;
 461                 lcparent = lc->parent;
 462         }
 463         if (lcparent == NULL)
 464                 return;
 465
 466         /* Work out the size adjustment. */
 467         if (type == LAYOUT_LEFTRIGHT)
 468                 size = lc->sx;
 469         else
 470                 size = lc->sy;
 471         if (lc == TAILQ_LAST(&lcparent->cells, layout_cells))
 472                 change = size - new_size;
 473         else
 474                 change = new_size - size;
 475
 476         /* Resize the pane. */
 477         layout_resize_pane(wp, type, change);
 478 }
 479
 480 /* Resize a single pane within the layout. */
 481 void
 482 layout_resize_pane(struct window_pane *wp, enum layout_type type, int change)
 483 {
 484         struct layout_cell     *lc, *lcparent;
 485         int                     needed, size;
 486
 487         lc = wp->layout_cell;
 488
 489         /* Find next parent of the same type. */
 490         lcparent = lc->parent;
 491         while (lcparent != NULL && lcparent->type != type) {
 492                 lc = lcparent;
 493                 lcparent = lc->parent;
 494         }
 495         if (lcparent == NULL)
 496                 return;
 497
 498         /* If this is the last cell, move back one. */
 499         if (lc == TAILQ_LAST(&lcparent->cells, layout_cells))
 500                 lc = TAILQ_PREV(lc, layout_cells, entry);
 501
 502         /* Grow or shrink the cell. */
 503         needed = change;
 504         while (needed != 0) {
 505                 if (change > 0) {
 506                         size = layout_resize_pane_grow(lc, type, needed);
 507                         needed -= size;
 508                 } else {
 509                         size = layout_resize_pane_shrink(lc, type, needed);
 510                         needed += size;
 511                 }
 512
 513                 if (size == 0)  /* no more change possible */
 514                         break;
 515         }
 516
 517         /* Fix cell offsets. */
 518         layout_fix_offsets(wp->window->layout_root);
 519         layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
 520         notify_window_layout_changed(wp->window);
 521 }
 522
 523 /* Resize pane based on mouse events. */
 524 void
 525 layout_resize_pane_mouse(struct client *c)
 526 {
 527         struct window           *w;
 528         struct window_pane      *wp;
 529         struct mouse_event      *m = &c->tty.mouse;
 530         int                      pane_border;
 531
 532         w = c->session->curw->window;
 533
 534         pane_border = 0;
 535         if (m->event & MOUSE_EVENT_DRAG && m->flags & MOUSE_RESIZE_PANE) {
 536                 TAILQ_FOREACH(wp, &w->panes, entry) {
 537                         if (!window_pane_visible(wp))
 538                                 continue;
 539
 540                         if (wp->xoff + wp->sx == m->lx &&
 541                             wp->yoff <= 1 + m->ly &&
 542                             wp->yoff + wp->sy >= m->ly) {
 543                                 layout_resize_pane(wp, LAYOUT_LEFTRIGHT,
 544                                     m->x - m->lx);
 545                                 pane_border = 1;
 546                         }
 547                         if (wp->yoff + wp->sy == m->ly &&
 548                             wp->xoff <= 1 + m->lx &&
 549                             wp->xoff + wp->sx >= m->lx) {
 550                                 layout_resize_pane(wp, LAYOUT_TOPBOTTOM,
 551                                     m->y - m->ly);
 552                                 pane_border = 1;
 553                         }
 554                 }
 555                 if (pane_border)
 556                         server_redraw_window(w);
 557         } else if (m->event & MOUSE_EVENT_DOWN) {
 558                 TAILQ_FOREACH(wp, &w->panes, entry) {
 559                         if ((wp->xoff + wp->sx == m->x &&
 560                             wp->yoff <= 1 + m->y &&
 561                             wp->yoff + wp->sy >= m->y) ||
 562                             (wp->yoff + wp->sy == m->y &&
 563                             wp->xoff <= 1 + m->x &&
 564                             wp->xoff + wp->sx >= m->x)) {
 565                                 pane_border = 1;
 566                         }
 567                 }
 568         }
 569         if (pane_border)
 570                 m->flags |= MOUSE_RESIZE_PANE;
 571         else
 572                 m->flags &= ~MOUSE_RESIZE_PANE;
 573 }
 574
 575 /* Helper function to grow pane. */
 576 int
 577 layout_resize_pane_grow(
 578     struct layout_cell *lc, enum layout_type type, int needed)
 579 {
 580         struct layout_cell      *lcadd, *lcremove;
 581         u_int                    size;
 582
 583         /* Growing. Always add to the current cell. */
 584         lcadd = lc;
 585
 586         /* Look towards the tail for a suitable cell for reduction. */
 587         lcremove = TAILQ_NEXT(lc, entry);
 588         while (lcremove != NULL) {
 589                 size = layout_resize_check(lcremove, type);
 590                 if (size > 0)
 591                         break;
 592                 lcremove = TAILQ_NEXT(lcremove, entry);
 593         }
 594
 595         /* If none found, look towards the head. */
 596         if (lcremove == NULL) {
 597                 lcremove = TAILQ_PREV(lc, layout_cells, entry);
 598                 while (lcremove != NULL) {
 599                         size = layout_resize_check(lcremove, type);
 600                         if (size > 0)
 601                                 break;
 602                         lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
 603                 }
 604                 if (lcremove == NULL)
 605                         return (0);
 606         }
 607
 608         /* Change the cells. */
 609         if (size > (u_int) needed)
 610                 size = needed;
 611         layout_resize_adjust(lcadd, type, size);
 612         layout_resize_adjust(lcremove, type, -size);
 613         return (size);
 614 }
 615
 616 /* Helper function to shrink pane. */
 617 int
 618 layout_resize_pane_shrink(
 619     struct layout_cell *lc, enum layout_type type, int needed)
 620 {
 621         struct layout_cell      *lcadd, *lcremove;
 622         u_int                    size;
 623
 624         /* Shrinking. Find cell to remove from by walking towards head. */
 625         lcremove = lc;
 626         do {
 627                 size = layout_resize_check(lcremove, type);
 628                 if (size != 0)
 629                         break;
 630                 lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
 631         } while (lcremove != NULL);
 632         if (lcremove == NULL)
 633                 return (0);
 634
 635         /* And add onto the next cell (from the original cell). */
 636         lcadd = TAILQ_NEXT(lc, entry);
 637         if (lcadd == NULL)
 638                 return (0);
 639
 640         /* Change the cells. */
 641         if (size > (u_int) -needed)
 642                 size = -needed;
 643         layout_resize_adjust(lcadd, type, size);
 644         layout_resize_adjust(lcremove, type, -size);
 645         return (size);
 646 }
 647
 648 /* Assign window pane to newly split cell. */
 649 void
 650 layout_assign_pane(struct layout_cell *lc, struct window_pane *wp)
 651 {
 652         layout_make_leaf(lc, wp);
 653         layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
 654 }
 655
 656 /*
 657  * Split a pane into two. size is a hint, or -1 for default half/half
 658  * split. This must be followed by layout_assign_pane before much else happens!
 659  **/
 660 struct layout_cell *
 661 layout_split_pane(
 662     struct window_pane *wp, enum layout_type type, int size, int insert_before)
 663 {
 664         struct layout_cell     *lc, *lcparent, *lcnew, *lc1, *lc2;
 665         u_int                   sx, sy, xoff, yoff, size1, size2;
 666
 667         lc = wp->layout_cell;
 668
 669         /* Copy the old cell size. */
 670         sx = lc->sx;
 671         sy = lc->sy;
 672         xoff = lc->xoff;
 673         yoff = lc->yoff;
 674
 675         /* Check there is enough space for the two new panes. */
 676         switch (type) {
 677         case LAYOUT_LEFTRIGHT:
 678                 if (sx < PANE_MINIMUM * 2 + 1)
 679                         return (NULL);
 680                 break;
 681         case LAYOUT_TOPBOTTOM:
 682                 if (sy < PANE_MINIMUM * 2 + 1)
 683                         return (NULL);
 684                 break;
 685         default:
 686                 fatalx("bad layout type");
 687         }
 688
 689         if (lc->parent != NULL && lc->parent->type == type) {
 690                 /*
 691                  * If the parent exists and is of the same type as the split,
 692                  * create a new cell and insert it after this one.
 693                  */
 694
 695                 /* Create the new child cell. */
 696                 lcparent = lc->parent;
 697                 lcnew = layout_create_cell(lcparent);
 698                 if (insert_before)
 699                         TAILQ_INSERT_BEFORE(lc, lcnew, entry);
 700                 else
 701                         TAILQ_INSERT_AFTER(&lcparent->cells, lc, lcnew, entry);
 702         } else {
 703                 /*
 704                  * Otherwise create a new parent and insert it.
 705                  */
 706
 707                 /* Create and insert the replacement parent. */
 708                 lcparent = layout_create_cell(lc->parent);
 709                 layout_make_node(lcparent, type);
 710                 layout_set_size(lcparent, sx, sy, xoff, yoff);
 711                 if (lc->parent == NULL)
 712                         wp->window->layout_root = lcparent;
 713                 else
 714                         TAILQ_REPLACE(&lc->parent->cells, lc, lcparent, entry);
 715
 716                 /* Insert the old cell. */
 717                 lc->parent = lcparent;
 718                 TAILQ_INSERT_HEAD(&lcparent->cells, lc, entry);
 719
 720                 /* Create the new child cell. */
 721                 lcnew = layout_create_cell(lcparent);
 722                 if (insert_before)
 723                         TAILQ_INSERT_HEAD(&lcparent->cells, lcnew, entry);
 724                 else
 725                         TAILQ_INSERT_TAIL(&lcparent->cells, lcnew, entry);
 726         }
 727         if (insert_before) {
 728                 lc1 = lcnew;
 729                 lc2 = lc;
 730         } else {
 731                 lc1 = lc;
 732                 lc2 = lcnew;
 733         }
 734
 735         /* Set new cell sizes.  size is the target size or -1 for middle split,
 736          * size1 is the size of the top/left and size2 the bottom/right.
 737          */
 738         switch (type) {
 739         case LAYOUT_LEFTRIGHT:
 740                 if (size < 0)
 741                         size2 = ((sx + 1) / 2) - 1;
 742                 else
 743                         size2 = size;
 744                 if (size2 < PANE_MINIMUM)
 745                         size2 = PANE_MINIMUM;
 746                 else if (size2 > sx - 2)
 747                         size2 = sx - 2;
 748                 size1 = sx - 1 - size2;
 749                 layout_set_size(lc1, size1, sy, xoff, yoff);
 750                 layout_set_size(lc2, size2, sy, xoff + lc1->sx + 1, yoff);
 751                 break;
 752         case LAYOUT_TOPBOTTOM:
 753                 if (size < 0)
 754                         size2 = ((sy + 1) / 2) - 1;
 755                 else
 756                         size2 = size;
 757                 if (size2 < PANE_MINIMUM)
 758                         size2 = PANE_MINIMUM;
 759                 else if (size2 > sy - 2)
 760                         size2 = sy - 2;
 761                 size1 = sy - 1 - size2;
 762                 layout_set_size(lc1, sx, size1, xoff, yoff);
 763                 layout_set_size(lc2, sx, size2, xoff, yoff + lc1->sy + 1);
 764                 break;
 765         default:
 766                 fatalx("bad layout type");
 767         }
 768
 769         /* Assign the panes. */
 770         layout_make_leaf(lc, wp);
 771
 772         return (lcnew);
 773 }
 774
 775 /* Destroy the cell associated with a pane. */
 776 void
 777 layout_close_pane(struct window_pane *wp)
 778 {
 779         /* Remove the cell. */
 780         layout_destroy_cell(wp->layout_cell, &wp->window->layout_root);
 781
 782         /* Fix pane offsets and sizes. */
 783         if (wp->window->layout_root != NULL) {
 784                 layout_fix_offsets(wp->window->layout_root);
 785                 layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
 786         }
 787         notify_window_layout_changed(wp->window);
 788 }