/src/tmux/screen-redraw.c

Source
/* $OpenBSD$ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <stdlib.h>
#include <string.h>

#include "tmux.h"

static void screen_redraw_draw_borders(struct screen_redraw_ctx *);
static void screen_redraw_draw_panes(struct screen_redraw_ctx *);
static void screen_redraw_draw_status(struct screen_redraw_ctx *);
static void screen_redraw_draw_pane(struct screen_redraw_ctx *,
        struct window_pane *);
static void screen_redraw_set_context(struct client *,
        struct screen_redraw_ctx *);
static void screen_redraw_draw_pane_scrollbars(struct screen_redraw_ctx *);
static void screen_redraw_draw_scrollbar(struct screen_redraw_ctx *,
        struct window_pane *, int, int, int, u_int, u_int, u_int);
static void screen_redraw_draw_pane_scrollbar(struct screen_redraw_ctx *,
        struct window_pane *);

#define START_ISOLATE "\342\201\246"
#define END_ISOLATE   "\342\201\251"

/* Border in relation to a pane. */
enum screen_redraw_border_type {
  SCREEN_REDRAW_OUTSIDE,
  SCREEN_REDRAW_INSIDE,
  SCREEN_REDRAW_BORDER_LEFT,
  SCREEN_REDRAW_BORDER_RIGHT,
  SCREEN_REDRAW_BORDER_TOP,
  SCREEN_REDRAW_BORDER_BOTTOM
};
#define BORDER_MARKERS "  +,.-"

/* Get cell border character. */
static void
screen_redraw_border_set(struct window *w, struct window_pane *wp,
    enum pane_lines pane_lines, int cell_type, struct grid_cell *gc)
{
  u_int idx;

  if (cell_type == CELL_OUTSIDE && w->fill_character != NULL) {
    utf8_copy(&gc->data, &w->fill_character[0]);
    return;
  }

  switch (pane_lines) {
  case PANE_LINES_NUMBER:
    if (cell_type == CELL_OUTSIDE) {
      gc->attr |= GRID_ATTR_CHARSET;
      utf8_set(&gc->data, CELL_BORDERS[CELL_OUTSIDE]);
      break;
    }
    gc->attr &= ~GRID_ATTR_CHARSET;
    if (wp != NULL && window_pane_index(wp, &idx) == 0)
      utf8_set(&gc->data, '0' + (idx % 10));
    else
      utf8_set(&gc->data, '*');
    break;
  case PANE_LINES_DOUBLE:
    gc->attr &= ~GRID_ATTR_CHARSET;
    utf8_copy(&gc->data, tty_acs_double_borders(cell_type));
    break;
  case PANE_LINES_HEAVY:
    gc->attr &= ~GRID_ATTR_CHARSET;
    utf8_copy(&gc->data, tty_acs_heavy_borders(cell_type));
    break;
  case PANE_LINES_SIMPLE:
    gc->attr &= ~GRID_ATTR_CHARSET;
    utf8_set(&gc->data, SIMPLE_BORDERS[cell_type]);
    break;
  case PANE_LINES_SPACES:
    gc->attr &= ~GRID_ATTR_CHARSET;
    utf8_set(&gc->data, ' ');
    break;
  default:
    gc->attr |= GRID_ATTR_CHARSET;
    utf8_set(&gc->data, CELL_BORDERS[cell_type]);
    break;
  }
}

/* Return 1 if window has only two panes. */
static int
screen_redraw_two_panes(struct window *w, enum layout_type *type)
{
  struct window_pane  *wp;
  u_int      count = 0;

  TAILQ_FOREACH(wp, &w->panes, entry) {
    if (window_pane_is_floating(wp) || wp->layout_cell == NULL)
      continue;
    count++;
    if (count > 2 || wp->layout_cell->parent == NULL)
      return (0);
    *type = wp->layout_cell->parent->type;
  }
  if (count <= 1)
    return (0);
  return (1);
}

/* Check if cell is on the border of a pane. */
static enum screen_redraw_border_type
screen_redraw_pane_border(struct screen_redraw_ctx *ctx, struct window_pane *wp,
    int px, int py)
{
  struct options  *oo = wp->window->options;
  int    ex = wp->xoff + wp->sx, ey = wp->yoff + wp->sy;
  int    hsplit = 0, vsplit = 0, pane_status = ctx->pane_status;
  int    pane_scrollbars = ctx->pane_scrollbars, sb_w = 0;
  int    sb_pos, sx = wp->sx, sy = wp->sy;
  enum layout_type split_type;

  if (pane_scrollbars != 0)
    sb_pos = ctx->pane_scrollbars_pos;
  else
    sb_pos = 0;

  /* Inside pane. */
  if (px >= wp->xoff && px < ex && py >= wp->yoff && py < ey)
    return (SCREEN_REDRAW_INSIDE);

  /* Are scrollbars enabled? */
  if (window_pane_show_scrollbar(wp, pane_scrollbars))
    sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;

  /* Floating pane borders. */
  if (window_pane_is_floating(wp)) {
    if (py >= wp->yoff - 1 && py <= wp->yoff + sy) {
      if (sb_pos == PANE_SCROLLBARS_LEFT) {
        if (px == wp->xoff - 1 - sb_w)
          return (SCREEN_REDRAW_BORDER_LEFT);
        if (px == wp->xoff + sx)
          return (SCREEN_REDRAW_BORDER_RIGHT);
      } else { /* PANE_SCROLLBARS_RIGHT or none. */
        if (px == wp->xoff - 1)
          return (SCREEN_REDRAW_BORDER_LEFT);
        if (px == wp->xoff + sx + sb_w)
          return (SCREEN_REDRAW_BORDER_RIGHT);
      }
    }
    if (px >= wp->xoff && px <= wp->xoff + sx) {
      if (py == wp->yoff - 1)
        return (SCREEN_REDRAW_BORDER_TOP);
      if (py == wp->yoff + sy)
        return (SCREEN_REDRAW_BORDER_BOTTOM);
    }
    return (SCREEN_REDRAW_OUTSIDE);
  }

  /* Get pane indicator. */
  switch (options_get_number(oo, "pane-border-indicators")) {
  case PANE_BORDER_COLOUR:
  case PANE_BORDER_BOTH:
    if (screen_redraw_two_panes(wp->window, &split_type)) {
      hsplit = (split_type == LAYOUT_LEFTRIGHT);
      vsplit = (split_type == LAYOUT_TOPBOTTOM);
    }
    break;
  }

  /*
   * Left/right borders. The sy / 2 test is to colour only half the
   * active window's border when there are two panes.
   */
  if ((wp->yoff == 0 || py >= wp->yoff - 1) && py <= ey) {
    if (sb_pos == PANE_SCROLLBARS_LEFT) {
      if (wp->xoff - sb_w == 0 && px == sx + sb_w) {
        if (!hsplit || (hsplit && py <= sy / 2))
          return (SCREEN_REDRAW_BORDER_RIGHT);
      }
      if (wp->xoff - sb_w != 0) {
        if (px == wp->xoff - sb_w - 1 &&
            (!hsplit || (hsplit && py > sy / 2)))
          return (SCREEN_REDRAW_BORDER_LEFT);
        if (px == wp->xoff + sx + sb_w - 1)
          return (SCREEN_REDRAW_BORDER_RIGHT);
      }
    } else { /* sb_pos == PANE_SCROLLBARS_RIGHT or disabled */
      if (wp->xoff == 0 && px == sx + sb_w) {
        if (!hsplit || (hsplit && py <= sy / 2))
          return (SCREEN_REDRAW_BORDER_RIGHT);
      }
      if (wp->xoff != 0) {
        if (px == wp->xoff - 1 &&
            (!hsplit || (hsplit && py > sy / 2)))
          return (SCREEN_REDRAW_BORDER_LEFT);
        if (px == wp->xoff + sx + sb_w)
          return (SCREEN_REDRAW_BORDER_RIGHT);
      }
    }
  }

  /* Top/bottom borders. */
  if (vsplit && pane_status == PANE_STATUS_OFF && sb_w == 0) {
    if (wp->yoff == 0 && py == sy && px <= sx / 2)
      return (SCREEN_REDRAW_BORDER_BOTTOM);
    if (wp->yoff != 0 && py == wp->yoff - 1 && px > sx / 2)
      return (SCREEN_REDRAW_BORDER_TOP);
  } else {
    if (sb_pos == PANE_SCROLLBARS_LEFT) {
      if ((wp->xoff - sb_w == 0 || px >= wp->xoff - sb_w) &&
          (px <= ex || (sb_w != 0 && px < ex + sb_w))) {
        if (wp->yoff != 0 && py == wp->yoff - 1)
          return (SCREEN_REDRAW_BORDER_TOP);
        if (py == ey)
          return (SCREEN_REDRAW_BORDER_BOTTOM);
      }
    } else { /* sb_pos == PANE_SCROLLBARS_RIGHT */
      if ((wp->xoff == 0 || px >= wp->xoff) &&
          (px <= ex || (sb_w != 0 && px < ex + sb_w))) {
        if (pane_status != PANE_STATUS_BOTTOM &&
            wp->yoff != 0 &&
            py == wp->yoff - 1)
          return (SCREEN_REDRAW_BORDER_TOP);
        if (pane_status != PANE_STATUS_TOP && py == ey)
          return (SCREEN_REDRAW_BORDER_BOTTOM);
      }
    }
  }

  /* Outside pane. */
  return (SCREEN_REDRAW_OUTSIDE);
}

/* Check a single cell position. */
static int
screen_redraw_cell_border1(struct screen_redraw_ctx *ctx, int sb_pos, int sb_w,
    struct window_pane *wp, int px, int py)
{
  if (sb_pos == PANE_SCROLLBARS_LEFT) {
    if ((px < wp->xoff - 1 - sb_w ||
        px > wp->xoff + (int)wp->sx) &&
        (py < wp->yoff - 1 ||
        py > wp->yoff + (int)wp->sy))
      return (-1);
  } else { /* PANE_SCROLLBARS_RIGHT or off. */
    if ((px < wp->xoff - 1 ||
        px > wp->xoff + (int)wp->sx + sb_w) &&
        (py < wp->yoff - 1 ||
        py > wp->yoff + (int)wp->sy))
      return (-1);
  }
  switch (screen_redraw_pane_border(ctx, wp, px, py)) {
  case SCREEN_REDRAW_INSIDE:
    return (0);
  case SCREEN_REDRAW_OUTSIDE:
    return (-1);
  default:
    return (1);
  }
}

/* Check if a cell is on a border. */
static int
screen_redraw_cell_border(struct screen_redraw_ctx *ctx, struct window_pane *wp,
    int px, int py)
{
  struct client   *c = ctx->c;
  struct window   *w = c->session->curw->window;
  struct window_pane  *wp2;
  int      sx = w->sx, sy = w->sy, sb_w, sb_pos, n;

  if (ctx->pane_scrollbars != 0)
    sb_pos = ctx->pane_scrollbars_pos;
  else
    sb_pos = 0;
  sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;

  /* For floating panes, only check the pane itself. */
  if (window_pane_is_floating(wp)) {
    n = screen_redraw_cell_border1(ctx, sb_pos, sb_w, wp, px, py);
    if (n == -1)
      return (0);
    return (n);
  }

  /* Outside the window or on the window border? */
  if (ctx->pane_status == PANE_STATUS_BOTTOM)
    sy--;
  if (px > sx || py > sy)
    return (0);
  if (px == sx || py == sy)
    return (1);

  /*
   * If checking a cell from a tiled pane, ignore floating panes because
   * two side-by-side or top-bottom panes share a border which is used to
   * do split colouring. Essentially, treat all tiled panes as being in a
   * single z-index.
   */
  TAILQ_FOREACH(wp2, &w->z_index, zentry) {
    if (!window_pane_visible(wp2) || window_pane_is_floating(wp2))
      continue;
    n = screen_redraw_cell_border1(ctx, sb_pos, sb_w, wp2, px, py);
    if (n != -1)
      return (n);
  }

  return (0);
}

/* Work out type of border cell from surrounding cells. */
static int
screen_redraw_type_of_cell(struct screen_redraw_ctx *ctx,
    struct window_pane *wp, int px, int py)
{
  struct client *c = ctx->c;
  struct window *w = c->session->curw->window;
  int    pane_status = ctx->pane_status, borders = 0;
  int    sx = w->sx, sy = w->sy;

  /* Is this outside the window? */
  if (pane_status == PANE_STATUS_BOTTOM)
    sy--;
  if (px > sx || py > sy)
    return (CELL_OUTSIDE);

  /*
   * Construct a bitmask of whether the cells to the left (bit 8), right,
   * top, and bottom (bit 1) of this cell are borders.
   *
   * bits 8 4 2 1:     2
   *       8 + 4
   *         1
   */
  if (!window_pane_is_floating(wp)) {
    if (px == 0 || screen_redraw_cell_border(ctx, wp, px - 1, py))
      borders |= 8;
    if (px <= sx && screen_redraw_cell_border(ctx, wp, px + 1, py))
      borders |= 4;
    if (pane_status == PANE_STATUS_TOP) {
      if (py != 0 &&
          screen_redraw_cell_border(ctx, wp, px, py - 1))
        borders |= 2;
      if (screen_redraw_cell_border(ctx, wp, px, py + 1))
        borders |= 1;
    } else if (pane_status == PANE_STATUS_BOTTOM) {
      if (py == 0 ||
          screen_redraw_cell_border(ctx, wp, px, py - 1))
        borders |= 2;
      if (py != sy &&
          screen_redraw_cell_border(ctx, wp, px, py + 1))
        borders |= 1;
    } else {
      if (py == 0 ||
          screen_redraw_cell_border(ctx, wp, px, py - 1))
        borders |= 2;
      if (screen_redraw_cell_border(ctx, wp, px, py + 1))
        borders |= 1;
    }
  } else {
    if (screen_redraw_cell_border(ctx, wp, px - 1, py))
      borders |= 8;
    if (px <= sx && screen_redraw_cell_border(ctx, wp, px + 1, py))
      borders |= 4;
    if (pane_status == PANE_STATUS_TOP) {
      if (py != 0 &&
          screen_redraw_cell_border(ctx, wp, px, py - 1))
        borders |= 2;
      if (screen_redraw_cell_border(ctx, wp, px, py + 1))
        borders |= 1;
    } else if (pane_status == PANE_STATUS_BOTTOM) {
      if (screen_redraw_cell_border(ctx, wp, px, py - 1))
        borders |= 2;
      if (py != sy &&
          screen_redraw_cell_border(ctx, wp, px, py + 1))
        borders |= 1;
    } else {
      if (screen_redraw_cell_border(ctx, wp, px, py - 1))
        borders |= 2;
      if (screen_redraw_cell_border(ctx, wp, px, py + 1))
        borders |= 1;
    }
  }

  /*
   * Figure out what kind of border this cell is. Only one bit set
   * doesn't make sense (can't have a border cell with no others
   * connected).
   */
  switch (borders) {
  case 15:  /* 1111, left right top bottom */
    return (CELL_JOIN);
  case 14:  /* 1110, left right top */
    return (CELL_BOTTOMJOIN);
  case 13:  /* 1101, left right bottom */
    return (CELL_TOPJOIN);
  case 12:  /* 1100, left right */
    return (CELL_LEFTRIGHT);
  case 11:  /* 1011, left top bottom */
    return (CELL_RIGHTJOIN);
  case 10:  /* 1010, left top */
    return (CELL_BOTTOMRIGHT);
  case 9:   /* 1001, left bottom */
    return (CELL_TOPRIGHT);
  case 7:   /* 0111, right top bottom */
    return (CELL_LEFTJOIN);
  case 6:   /* 0110, right top */
    return (CELL_BOTTOMLEFT);
  case 5:   /* 0101, right bottom */
    return (CELL_TOPLEFT);
  case 3:   /* 0011, top bottom */
    return (CELL_TOPBOTTOM);
  }
  return (CELL_OUTSIDE);
}

/* Check if cell inside a pane. */
static int
screen_redraw_check_cell(struct screen_redraw_ctx *ctx, int px, int py,
    struct window_pane **wpp)
{
  struct client   *c = ctx->c;
  struct window   *w = c->session->curw->window;
  struct window_pane  *wp, *start;
  int      sx = w->sx, sy = w->sy;
  int      pane_status = ctx->pane_status;
  int      border, pane_scrollbars = ctx->pane_scrollbars;
  int      pane_status_line, tiled_only = 0, left, right;
  int      sb_pos = ctx->pane_scrollbars_pos, sb_w;

  *wpp = NULL;

  /* Outside the pane. */
  if (px > sx || py > sy)
    return (CELL_OUTSIDE);

  /* Find pane highest in z-index at this point. */
  TAILQ_FOREACH(wp, &w->z_index, zentry) {
    if (window_pane_is_floating(wp) && (px >= sx || py >= sy)) {
      /* Clip floating panes to window. */
      continue;
    }
    sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
    if (sb_pos == PANE_SCROLLBARS_LEFT) {
      if ((px >= wp->xoff - 1 - sb_w &&
          px <= wp->xoff + (int)wp->sx) &&
          (py >= wp->yoff - 1 &&
          py <= wp->yoff + (int)wp->sy))
        break;
    } else { /* PANE_SCROLLBARS_RIGHT or none. */
      if ((px >= wp->xoff - 1 &&
          px <= wp->xoff + (int)wp->sx + sb_w) &&
          (py >= wp->yoff - 1 &&
          py <= wp->yoff + (int)wp->sy))
        break;
    }
  }
  if (wp != NULL)
    start = wp;
  else
    start = wp = server_client_get_pane(c);
  if (wp == NULL)
    return (CELL_OUTSIDE);

  /* On the window border. */
  if (px == sx || py == sy)
    return (screen_redraw_type_of_cell(ctx, wp, px, py));

  /*
   * If this is a tiled pane, then only check other tiled panes. This is
   * necessary if there are two side-by-side or top-bottom panes with a
   * shared border and half the shared border is the active border.
   */
  if (!window_pane_is_floating(wp))
    tiled_only = 1;
  do { /* loop until back to wp == start */
    if (!window_pane_visible(wp))
      goto next;
    if (tiled_only && window_pane_is_floating(wp))
      goto next;
    *wpp = wp;

    sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
    if (sb_pos == PANE_SCROLLBARS_LEFT) {
      if ((px < wp->xoff - 1 - sb_w ||
           px > wp->xoff + (int)wp->sx) &&
          (py < wp->yoff - 1 ||
          py > wp->yoff + (int)wp->sy))
        goto next;
    } else { /* PANE_SCROLLBARS_RIGHT or none */
      if ((px < wp->xoff - 1 ||
           px > wp->xoff + (int)wp->sx + sb_w) &&
          (py < wp->yoff - 1 ||
           py > wp->yoff + (int)wp->sy))
        goto next;
    }

    /*
     * Pane border status inside top/bottom border is CELL_INSIDE
     * so it doesn't get overdrawn by a border line.
     */
    if (pane_status != PANE_STATUS_OFF) {
      if (pane_status == PANE_STATUS_TOP)
        pane_status_line = wp->yoff - 1;
      else
        pane_status_line = wp->yoff + (int)wp->sy;
      left = wp->xoff + 2;
      right = wp->xoff + 2 + (int)wp->status_size - 1;
      if (py == pane_status_line + (int)ctx->oy &&
          px >= left &&
          px <= right)
        return (CELL_INSIDE);
    }

    /* Check if CELL_SCROLLBAR. */
    if (window_pane_show_scrollbar(wp, pane_scrollbars)) {
      /*
       * Check if py could lie within a scrollbar. If the
       * pane is at the top then py == 0 to sy; if the pane
       * is not at the top, then yoff to yoff + sy.
       */
      sb_w = wp->scrollbar_style.width +
          wp->scrollbar_style.pad;
      if ((wp->yoff == 0 && py < (int)wp->sy) ||
          (py >= wp->yoff &&
           py < wp->yoff + (int)wp->sy)) {
        /* Check if px lies within a scrollbar. */
        if ((sb_pos == PANE_SCROLLBARS_RIGHT &&
            (px >= wp->xoff + (int)wp->sx &&
            px < wp->xoff + (int)wp->sx + sb_w)) ||
            (sb_pos == PANE_SCROLLBARS_LEFT &&
            (px >= wp->xoff - sb_w &&
            px < wp->xoff)))
          return (CELL_SCROLLBAR);
      }
    }

    /*
     * If definitely inside, return. If not on border, skip.
     * Otherwise work out the cell.
     */
    border = screen_redraw_pane_border(ctx, wp, px, py);
    if (border == SCREEN_REDRAW_INSIDE)
      return (CELL_INSIDE);
    if (border == SCREEN_REDRAW_OUTSIDE)
      goto next;
    return (screen_redraw_type_of_cell(ctx, wp, px, py));

  next:
    wp = TAILQ_NEXT(wp, zentry);
    if (wp == NULL)
      wp = TAILQ_FIRST(&w->z_index);
  } while (wp != start);

  return (CELL_OUTSIDE);
}

/* Check if the border of a particular pane. */
static int
screen_redraw_check_is(struct screen_redraw_ctx *ctx, int px, int py,
    struct window_pane *wp)
{
  enum screen_redraw_border_type  border;

  if (wp == NULL)
    return (0); /* no active pane */
  border = screen_redraw_pane_border(ctx, wp, px, py);
  if (border != SCREEN_REDRAW_INSIDE && border != SCREEN_REDRAW_OUTSIDE)
    return (1);
  return (0);
}

/* Update pane status. */
static int
screen_redraw_make_pane_status(struct client *c, struct window_pane *wp,
    struct screen_redraw_ctx *rctx, enum pane_lines pane_lines)
{
  struct window   *w = wp->window;
  struct grid_cell   gc;
  const char    *fmt, *border_option;
  struct format_tree  *ft;
  struct style_line_entry *sle = &wp->border_status_line;
  char      *expanded;
  int      pane_status = rctx->pane_status, sb_w = 0;
  int      pane_scrollbars = rctx->pane_scrollbars;
  int      max_width;
  u_int      width, i, cell_type, px, py;
  struct screen_write_ctx  ctx;
  struct screen    old;

  if (window_pane_show_scrollbar(wp, pane_scrollbars))
    sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;

  ft = format_create(c, NULL, FORMAT_PANE|wp->id, FORMAT_STATUS);
  format_defaults(ft, c, c->session, c->session->curw, wp);

  if (wp == server_client_get_pane(c))
    border_option = "pane-active-border-style";
  else
    border_option = "pane-border-style";
  style_apply(&gc, wp->options, border_option, ft);
  fmt = options_get_string(wp->options, "pane-border-format");

  expanded = format_expand_time(ft, fmt);
  if (wp->sx < 4)
    width = 0;
  else
    width = wp->sx + sb_w - 2;
  max_width = (int)w->sx - (wp->xoff + 2) - sb_w;
  if (max_width < 0)
    max_width = 0;
  if (width > (u_int)max_width)
    width = (u_int)max_width;
  wp->status_size = width;

  memcpy(&old, &wp->status_screen, sizeof old);
  screen_init(&wp->status_screen, width, 1, 0);
  wp->status_screen.mode = 0;

  screen_write_start(&ctx, &wp->status_screen);

  for (i = 0; i < width; i++) {
    px = wp->xoff + 2 + i;
    if (pane_status == PANE_STATUS_TOP)
      py = wp->yoff - 1;
    else
      py = wp->yoff + wp->sy;
    cell_type = screen_redraw_type_of_cell(rctx, wp, px, py);
    screen_redraw_border_set(w, wp, pane_lines, cell_type, &gc);
    screen_write_cell(&ctx, &gc);
  }
  gc.attr &= ~GRID_ATTR_CHARSET;

  screen_write_cursormove(&ctx, 0, 0, 0);
  style_ranges_free(&sle->ranges);
  format_draw(&ctx, &gc, width, expanded, &sle->ranges, 0);

  screen_write_stop(&ctx);
  format_free(ft);

  free(sle->expanded);
  sle->expanded = expanded;

  if (grid_compare(wp->status_screen.grid, old.grid) == 0) {
    screen_free(&old);
    return (0);
  }
  screen_free(&old);
  return (1);
}

/* Draw pane status. */
static void
screen_redraw_draw_pane_status(struct screen_redraw_ctx *ctx)
{
  struct client   *c = ctx->c;
  struct window   *w = c->session->curw->window;
  struct tty    *tty = &c->tty;
  struct window_pane  *wp;
  struct screen   *s;
  struct visible_ranges *r;
  struct visible_range  *ri;
  u_int      i, l, x, width, size;
  int      xoff, yoff;

  log_debug("%s: %s @%u", __func__, c->name, w->id);

  TAILQ_FOREACH(wp, &w->panes, entry) {
    if (!window_pane_visible(wp))
      continue;
    s = &wp->status_screen;

    size = wp->status_size;
    if (ctx->pane_status == PANE_STATUS_TOP)
      yoff = wp->yoff - 1;
    else
      yoff = wp->yoff + wp->sy;
    xoff = wp->xoff + 2;

    if (xoff + (int)size <= ctx->ox ||
        xoff >= ctx->ox + (int)ctx->sx ||
        yoff < ctx->oy ||
        yoff >= ctx->oy + (int)ctx->sy)
      continue;

    if (xoff >= ctx->ox && xoff + size <= ctx->ox + ctx->sx) {
      /* All visible. */
      l = 0;
      x = xoff - ctx->ox;
      width = size;
    } else if (xoff < ctx->ox && xoff + size > ctx->ox + ctx->sx) {
      /* Both left and right not visible. */
      l = ctx->ox;
      x = 0;
      width = ctx->sx;
    } else if (xoff < ctx->ox) {
      /* Left not visible. */
      l = ctx->ox - xoff;
      x = 0;
      width = size - l;
    } else {
      /* Right not visible. */
      l = 0;
      x = xoff - ctx->ox;
      width = size - x;
    }

    r = tty_check_overlay_range(tty, x, yoff, width);
    r = screen_redraw_get_visible_ranges(wp, x, yoff, width, r);
    if (ctx->statustop)
      yoff += ctx->statuslines;
    for (i = 0; i < r->used; i++) {
      ri = &r->ranges[i];
      if (ri->nx == 0)
        continue;
      tty_draw_line(tty, s, l + (ri->px - x), 0, ri->nx,
          ri->px, yoff - ctx->oy,
          &grid_default_cell, NULL);
    }
  }
  tty_cursor(tty, 0, 0);
}

/* Update status line and change flags if unchanged. */
static uint64_t
screen_redraw_update(struct screen_redraw_ctx *ctx, uint64_t flags)
{
  struct client     *c = ctx->c;
  struct window     *w = c->session->curw->window;
  struct window_pane    *wp;
  int        redraw;
  enum pane_lines      lines;

  if (c->message_string != NULL)
    redraw = status_message_redraw(c);
  else if (c->prompt_string != NULL)
    redraw = status_prompt_redraw(c);
  else
    redraw = status_redraw(c);
  if (!redraw && (~flags & CLIENT_REDRAWSTATUSALWAYS))
    flags &= ~CLIENT_REDRAWSTATUS;

  if (c->overlay_draw != NULL)
    flags |= CLIENT_REDRAWOVERLAY;

  if (ctx->pane_status != PANE_STATUS_OFF) {
    lines = ctx->pane_lines;
    redraw = 0;
    TAILQ_FOREACH(wp, &w->panes, entry) {
      if (screen_redraw_make_pane_status(c, wp, ctx, lines))
        redraw = 1;
    }
    if (redraw)
      flags |= CLIENT_REDRAWBORDERS;
  }

  return (flags);
}

/* Set up redraw context. */
static void
screen_redraw_set_context(struct client *c, struct screen_redraw_ctx *ctx)
{
  struct session  *s = c->session;
  struct options  *oo = s->options;
  struct window *w = s->curw->window;
  struct options  *wo = w->options;
  u_int    lines;

  memset(ctx, 0, sizeof *ctx);
  ctx->c = c;

  lines = status_line_size(c);
  if (c->message_string != NULL || c->prompt_string != NULL)
    lines = (lines == 0) ? 1 : lines;
  if (lines != 0 && options_get_number(oo, "status-position") == 0)
    ctx->statustop = 1;
  ctx->statuslines = lines;

  ctx->pane_status = options_get_number(wo, "pane-border-status");
  ctx->pane_lines = options_get_number(wo, "pane-border-lines");

  ctx->pane_scrollbars = options_get_number(wo, "pane-scrollbars");
  ctx->pane_scrollbars_pos = options_get_number(wo,
      "pane-scrollbars-position");

  tty_window_offset(&c->tty, &ctx->ox, &ctx->oy, &ctx->sx, &ctx->sy);

  log_debug("%s: %s @%u ox=%u oy=%u sx=%u sy=%u %u/%d", __func__, c->name,
      w->id, ctx->ox, ctx->oy, ctx->sx, ctx->sy, ctx->statuslines,
      ctx->statustop);
}

/* Redraw entire screen. */
void
screen_redraw_screen(struct client *c)
{
  struct screen_redraw_ctx  ctx;
  uint64_t      flags;

  if (c->flags & CLIENT_SUSPENDED)
    return;

  screen_redraw_set_context(c, &ctx);

  flags = screen_redraw_update(&ctx, c->flags);
  if ((flags & CLIENT_ALLREDRAWFLAGS) == 0)
    return;

  tty_sync_start(&c->tty);
  tty_update_mode(&c->tty, c->tty.mode, NULL);

  if (flags & (CLIENT_REDRAWWINDOW|CLIENT_REDRAWBORDERS)) {
    log_debug("%s: redrawing borders", c->name);
    screen_redraw_draw_borders(&ctx);
    if (ctx.pane_status != PANE_STATUS_OFF)
      screen_redraw_draw_pane_status(&ctx);
    screen_redraw_draw_pane_scrollbars(&ctx);
  }
  if (flags & CLIENT_REDRAWWINDOW) {
    log_debug("%s: redrawing panes", c->name);
    screen_redraw_draw_panes(&ctx);
    screen_redraw_draw_pane_scrollbars(&ctx);
  }
  if (ctx.statuslines != 0 &&
      (flags & (CLIENT_REDRAWSTATUS|CLIENT_REDRAWSTATUSALWAYS))) {
    log_debug("%s: redrawing status", c->name);
    screen_redraw_draw_status(&ctx);
  }
  if (c->overlay_draw != NULL && (flags & CLIENT_REDRAWOVERLAY)) {
    log_debug("%s: redrawing overlay", c->name);
    c->overlay_draw(c, c->overlay_data, &ctx);
  }

  tty_reset(&c->tty);
}

/* Redraw a single pane and its scrollbar. */
void
screen_redraw_pane(struct client *c, struct window_pane *wp,
    int redraw_scrollbar_only)
{
  struct screen_redraw_ctx  ctx;

  if (!window_pane_visible(wp))
    return;

  screen_redraw_set_context(c, &ctx);
  tty_sync_start(&c->tty);
  tty_update_mode(&c->tty, c->tty.mode, NULL);

  if (!redraw_scrollbar_only)
    screen_redraw_draw_pane(&ctx, wp);

  if (window_pane_show_scrollbar(wp, ctx.pane_scrollbars))
    screen_redraw_draw_pane_scrollbar(&ctx, wp);

  tty_reset(&c->tty);
}

/* Get border cell style. */
static void
screen_redraw_draw_borders_style(struct screen_redraw_ctx *ctx, u_int x,
    u_int y, struct window_pane *wp, struct grid_cell *ngc)
{
  struct client   *c = ctx->c;
  struct session    *s = c->session;
  struct window_pane  *active = server_client_get_pane(c);
  struct grid_cell  *gc;
  const char    *border_option;
  struct format_tree  *ft;
  int     *flag;

  if ((window_pane_is_floating(wp) && wp == active) ||
      (!window_pane_is_floating(wp) &&
      screen_redraw_check_is(ctx, x, y, active))) {
    flag = &wp->active_border_gc_set;
    gc = &wp->active_border_gc;
    border_option = "pane-active-border-style";
  } else {
    flag = &wp->border_gc_set;
    gc = &wp->border_gc;
    border_option = "pane-border-style";
  }

  if (!*flag) {
    ft = format_create_defaults(NULL, c, s, s->curw, wp);
    style_apply(gc, wp->options, border_option, ft);
    format_free(ft);
    *flag = 1;
  }
  memcpy(ngc, gc, sizeof *ngc);
}

/* Draw arrow indicator if enabled. */
static void
screen_redraw_draw_border_arrows(struct screen_redraw_ctx *ctx, int i,
    int j, u_int cell_type, struct window_pane *wp,
    struct window_pane *active, struct grid_cell *gc)
{
  struct client   *c = ctx->c;
  struct session    *s = c->session;
  struct window   *w = s->curw->window;
  struct options    *oo = w->options;
  u_int      x = ctx->ox + i, y = ctx->oy + j;
  int      value, arrows = 0, border;
  enum layout_type   type;

  if (wp == NULL)
    return;
  if (i != wp->xoff + 1 && j != wp->yoff + 1)
    return;

  if (wp != active) {
    if (window_pane_is_floating(active))
      return;
    if (window_pane_is_floating(wp))
      return;
  }

  value = options_get_number(oo, "pane-border-indicators");
  if (value != PANE_BORDER_ARROWS && value != PANE_BORDER_BOTH)
    return;

  border = screen_redraw_pane_border(ctx, active, x, y);
  if (border == SCREEN_REDRAW_INSIDE)
    return;

  if (i == wp->xoff + 1) {
    if (border == SCREEN_REDRAW_OUTSIDE) {
      if (screen_redraw_two_panes(wp->window, &type)) {
        if (active == TAILQ_FIRST(&w->panes))
          border = SCREEN_REDRAW_BORDER_BOTTOM;
        else
          border = SCREEN_REDRAW_BORDER_TOP;
        arrows = 1;
      }
    } else {
      if (cell_type == CELL_LEFTRIGHT)
        arrows = 1;
      else if (cell_type == CELL_TOPJOIN &&
          border == SCREEN_REDRAW_BORDER_BOTTOM)
        arrows = 1;
      else if (cell_type == CELL_BOTTOMJOIN &&
          border == SCREEN_REDRAW_BORDER_TOP)
        arrows = 1;
    }
  }
  if (j == wp->yoff + 1) {
    if (border == SCREEN_REDRAW_OUTSIDE) {
      if (screen_redraw_two_panes(wp->window, &type)) {
        if (active == TAILQ_FIRST(&w->panes))
          border = SCREEN_REDRAW_BORDER_RIGHT;
        else
          border = SCREEN_REDRAW_BORDER_LEFT;
        arrows = 1;
      }
    } else {
      if (cell_type == CELL_TOPBOTTOM)
        arrows = 1;
      else if (cell_type == CELL_LEFTJOIN &&
          border == SCREEN_REDRAW_BORDER_RIGHT)
        arrows = 1;
      else if (cell_type == CELL_RIGHTJOIN &&
          border == SCREEN_REDRAW_BORDER_LEFT)
        arrows = 1;
    }
  }
  if (arrows) {
    gc->attr |= GRID_ATTR_CHARSET;
    utf8_set(&gc->data, BORDER_MARKERS[border]);
  }
}

/* Draw a border cell. */
static void
screen_redraw_draw_borders_cell(struct screen_redraw_ctx *ctx, u_int i, u_int j)
{
  struct client   *c = ctx->c;
  struct session    *s = c->session;
  struct window   *w = s->curw->window;
  struct options    *oo = w->options;
  struct tty    *tty = &c->tty;
  struct format_tree  *ft;
  struct window_pane  *wp, *active = server_client_get_pane(c);
  struct grid_cell   gc;
  u_int      cell_type;
  u_int      x = ctx->ox + i, y = ctx->oy + j;
  int      isolates;
  struct visible_ranges *r;

  if (c->overlay_check != NULL) {
    r = c->overlay_check(c, c->overlay_data, x, y, 1);
    if (server_client_ranges_is_empty(r))
      return;
  }

  cell_type = screen_redraw_check_cell(ctx, x, y, &wp);
  if (cell_type == CELL_INSIDE || cell_type == CELL_SCROLLBAR)
    return;

  if (wp == NULL || cell_type == CELL_OUTSIDE) {
    if (!ctx->no_pane_gc_set) {
      ft = format_create_defaults(NULL, c, s, s->curw, NULL);
      memcpy(&ctx->no_pane_gc, &grid_default_cell, sizeof gc);
      style_add(&ctx->no_pane_gc, oo, "pane-border-style",
          ft);
      format_free(ft);
      ctx->no_pane_gc_set = 1;
    }
    memcpy(&gc, &ctx->no_pane_gc, sizeof gc);
  } else {
    screen_redraw_draw_borders_style(ctx, x, y, wp, &gc);
    if (server_is_marked(s, s->curw, marked_pane.wp) &&
        screen_redraw_check_is(ctx, x, y, marked_pane.wp))
      gc.attr ^= GRID_ATTR_REVERSE;
  }
  screen_redraw_border_set(w, wp, ctx->pane_lines, cell_type, &gc);

  if (cell_type == CELL_TOPBOTTOM &&
      (c->flags & CLIENT_UTF8) &&
      tty_term_has(tty->term, TTYC_BIDI))
    isolates = 1;
  else
    isolates = 0;

  if (ctx->statustop)
    tty_cursor(tty, i, ctx->statuslines + j);
  else
    tty_cursor(tty, i, j);
  if (isolates)
    tty_puts(tty, END_ISOLATE);

  screen_redraw_draw_border_arrows(ctx, i, j, cell_type, wp, active, &gc);

  tty_cell(tty, &gc, &grid_default_cell, NULL, NULL);
  if (isolates)
    tty_puts(tty, START_ISOLATE);
}

/* Draw the borders. */
static void
screen_redraw_draw_borders(struct screen_redraw_ctx *ctx)
{
  struct client   *c = ctx->c;
  struct session    *s = c->session;
  struct window   *w = s->curw->window;
  struct window_pane  *wp;
  u_int      i, j;

  log_debug("%s: %s @%u", __func__, c->name, w->id);

  TAILQ_FOREACH(wp, &w->panes, entry) {
    wp->border_gc_set = 0;
    wp->active_border_gc_set = 0;
  }

  for (j = 0; j < c->tty.sy - ctx->statuslines; j++) {
    for (i = 0; i < c->tty.sx; i++)
      screen_redraw_draw_borders_cell(ctx, i, j);
  }
}

/* Draw the panes. */
static void
screen_redraw_draw_panes(struct screen_redraw_ctx *ctx)
{
  struct client   *c = ctx->c;
  struct window   *w = c->session->curw->window;
  struct window_pane  *wp;

  log_debug("%s: %s @%u", __func__, c->name, w->id);

  TAILQ_FOREACH(wp, &w->panes, entry) {
    if (window_pane_visible(wp))
      screen_redraw_draw_pane(ctx, wp);
  }
}

/* Draw the status line. */
static void
screen_redraw_draw_status(struct screen_redraw_ctx *ctx)
{
  struct client *c = ctx->c;
  struct window *w = c->session->curw->window;
  struct tty  *tty = &c->tty;
  struct screen *s = c->status.active;
  u_int    i, y;

  log_debug("%s: %s @%u", __func__, c->name, w->id);

  if (ctx->statustop)
    y = 0;
  else
    y = c->tty.sy - ctx->statuslines;
  for (i = 0; i < ctx->statuslines; i++) {
    tty_draw_line(tty, s, 0, i, UINT_MAX, 0, y + i,
        &grid_default_cell, NULL);
  }
}

/*
 * Check if a single character is within a visible range (not obscured by a
 * floating pane).
 */
int
screen_redraw_is_visible(struct visible_ranges *r, u_int px)
{
  u_int      i;
  struct visible_range  *ri;

  if (r == NULL)
    return (1);
  for (i = 0; i < r->used; i++) {
    ri = &r->ranges[i];
    if (ri->nx != 0 && px >= ri->px && px <= ri->px + ri->nx)
      return (1);
  }
  return (0);
}

/*
 * Construct ranges array for the line at starting at px,py of width cells of
 * base_wp that are unobsructed. All ranges are in window coordinates.
 */
struct visible_ranges *
screen_redraw_get_visible_ranges(struct window_pane *base_wp, int px,
    int py, u_int width, struct visible_ranges *r)
{
  struct window_pane    *wp;
  struct window     *w;
  struct visible_range    *ri;
  static struct visible_ranges   sr = { NULL, 0, 0 };
  int        found_self, sb, sb_w, sb_pos;
  u_int        lb, rb, tb, bb;
  u_int        i, s;

  if (px + width <= 0 || py < 0)
    goto empty;
  if (px < 0) {
    px = 0;
    width += px;
  }

  if (base_wp == NULL) {
    if (r != NULL)
      return (r);
    if (sr.ranges == NULL)
      sr.ranges = xcalloc(1, sizeof *sr.ranges);
    sr.ranges[0].px = px;
    sr.ranges[0].nx = width;
    sr.size = 1;
    sr.used = 1;
    return (&sr);
  }

  w = base_wp->window;
  if ((u_int)py >= w->sy)
    goto empty;
  if (px + width > w->sx)
    width = w->sx - px;

  if (r == NULL) {
    /* Start with the entire width of the range. */
    server_client_ensure_ranges(&base_wp->r, 1);
    r = &base_wp->r;
    r->ranges[0].px = px;
    r->ranges[0].nx = width;
    r->used = 1;
  }

  sb = options_get_number(w->options, "pane-scrollbars");
  sb_pos = options_get_number(w->options, "pane-scrollbars-position");

  found_self = 0;
  TAILQ_FOREACH_REVERSE(wp, &w->z_index, window_panes_zindex, zentry) {
    if (wp == base_wp) {
      found_self = 1;
      continue;
    }

    tb = wp->yoff > 0 ? wp->yoff - 1 : 0;
    bb = wp->yoff + wp->sy;
    if (!found_self ||
        !window_pane_visible(wp) ||
        (u_int)py < tb ||
        (u_int)py > bb)
      continue;
    if (!window_pane_is_floating(wp) && (u_int)py == bb)
      continue;

    sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
    if (!window_pane_show_scrollbar(wp, sb))
      sb_w = sb_pos = 0;

    for (i = 0; i < r->used; i++) {
      ri = &r->ranges[i];
      if (sb_pos == PANE_SCROLLBARS_LEFT) {
        if (wp->xoff > sb_w)
          lb = wp->xoff - 1 - sb_w;
        else
          lb = 0;
      } else { /* PANE_SCROLLBARS_RIGHT or none. */
        if (wp->xoff > 0)
          lb = wp->xoff - 1;
        else
          lb = 0;
      }
      if (sb_pos == PANE_SCROLLBARS_LEFT)
        rb = wp->xoff + wp->sx;
      else /* PANE_SCROLLBARS_RIGHT or none. */
        rb = wp->xoff + wp->sx + sb_w;
      if (rb > w->sx)
        rb = w->sx - 1;

      if (lb > ri->px &&
          lb < ri->px + ri->nx &&
          rb >= ri->px + ri->nx)
      {
        /*
         * If the left edge of floating pane falls
         * inside this range and right edge covers up
         * to right of range, then shrink left edge of
         * range.
         */
        ri->nx = lb - ri->px;
      }
      else if (rb >= ri->px &&
          rb < ri->px + ri->nx &&
          lb <= ri->px) {
        /*
         * Else if the right edge of floating pane falls
         * inside of this range and left edge covers
         * the left of range, then move px forward to
         * right edge of pane.
         */
        ri->nx = ri->nx - (rb + 1 - ri->px);
        ri->px = ri->px + (rb + 1 - ri->px);
      }
      else if (lb > ri->px && rb < ri->px + ri->nx) {
        /*
         * Else if pane fully inside range then split
         * into 2 ranges.
         */
        server_client_ensure_ranges(r, r->used + 1);
        for (s = r->used; s > i; s--) {
          memcpy(&r->ranges[s], &r->ranges[s - 1],
              sizeof *r->ranges);
        }
        ri = &r->ranges[i];
        r->ranges[i + 1].px = rb + 1;
        r->ranges[i + 1].nx = ri->px + ri->nx - (rb + 1);
        /* ri->px was copied, unchanged. */
        ri->nx = lb - ri->px;
        r->used++;
      } else if (lb <= ri->px && rb >= ri->px + ri->nx) {
        /*
         * If floating pane completely covers this range
         * then delete it (make it 0 length).
         */
        ri->nx = 0;
      } else {
        /*
         * The range is already obscured, do
         * nothing.
         */
      }
    }
  }
  return (r);

empty:
  if (r == NULL) {
    if (sr.ranges == NULL)
      sr.ranges = xcalloc(1, sizeof *sr.ranges);
    sr.size = 1;
    sr.used = 0;
    return (&sr);
  }
  r->used = 0;
  return (r);
}

/* Draw one pane. */
static void
screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
{
  struct client   *c = ctx->c;
  struct window   *w = c->session->curw->window;
  struct tty    *tty = &c->tty;
  struct screen   *s = wp->screen;
  struct colour_palette *palette = &wp->palette;
  struct grid_cell   defaults;
  u_int      j, k, woy, wx, wy, py, width;
  struct visible_ranges *r;
  struct visible_range  *ri;

  /*
   * There are 3 coordinate spaces:
   *
   * window: (0 to w->sx-1, 0 to w->sy-1)
   * tty: (0 to tty->sx-1, 0 to tty->sy-1)
   * pane: (0 to wp->sx-1, 0 to wp->sy-1)
   *
   * Transformations:
   * window <-> tty (x-axis):
   *   window_x = tty_x + ctx->ox
   *   tty_x = window_x - ctx->ox
   *
   * window <-> tty (y-axis):
   *   woy = ctx->statustop ? ctx->statuslines : 0
   *   window_y = tty_y + ctx->oy - woy
   *   tty_y = woy + window_y - ctx->oy
   *
   * window <-> pane (x-axis):
   *   window_x = pane_x + wp->xoff
   *   pane_x = window_x - wp->xoff
   *
   * window <-> pane (y-axis):
   *   window_y = pane_y + wp->yoff
   *   pane_y = window_y - wp->yoff
   */

  if (wp->base.mode & MODE_SYNC)
    screen_write_stop_sync(wp);

  log_debug("%s: %s @%u %%%u", __func__, c->name, w->id, wp->id);

  /* Check if pane completely not visible. */
  if (wp->xoff + (int)wp->sx <= ctx->ox ||
      wp->xoff >= (int)ctx->ox + (int)ctx->sx)
    return;

  if (ctx->statustop)
    woy = ctx->statuslines;
  else
    woy = 0;
  for (j = 0; j < wp->sy; j++) {
    if (wp->yoff + (int)j < (int)ctx->oy ||
        wp->yoff + (int)j >= (int)ctx->oy + (int)ctx->sy)
      continue;
    wy = wp->yoff + j; /* y line within window w */
    py = woy + wy - ctx->oy; /* y line within tty */
    if (py > tty->sy) {
      /* Continue if this line is off of tty. */
      continue;
    }
    if (wp->xoff >= (int)ctx->ox &&
        wp->xoff + (int)wp->sx <= (int)ctx->ox + (int)ctx->sx) {
      /* All visible. */
      wx = (u_int)(wp->xoff - (int)ctx->ox);
      width = wp->sx;
    } else if (wp->xoff < (int)ctx->ox &&
        wp->xoff + (int)wp->sx > (int)ctx->ox + (int)ctx->sx) {
      /* Both left and right not visible. */
      wx = 0;
      width = ctx->sx;
    } else if (wp->xoff < (int)ctx->ox) {
      /* Left not visible. */
      wx = 0;
      width = wp->sx - ((u_int)((int)ctx->ox - wp->xoff));
    } else {
      /* Right not visible. */
      wx = (u_int)(wp->xoff - (int)ctx->ox);
      width = ctx->sx - wx;
    }

    /* Get visible ranges of line before we draw it. */
    r = tty_check_overlay_range(tty, wx, wy, width);
    r = screen_redraw_get_visible_ranges(wp, wx, wy, width, r);
    tty_default_colours(&defaults, wp);
    for (k = 0; k < r->used; k++) {
      ri = &r->ranges[k];
      if (ri->nx == 0)
        continue;
      log_debug("%s: %s %%%u range %u (%u,%u) width %u, "
          "tty (%u,%u) width %u",
          __func__, c->name, wp->id, k,
          ri->px + (int)ctx->ox - wp->xoff, j, ri->nx,
          ri->px, py, ri->nx);
      tty_draw_line(tty, s, ri->px + (int)ctx->ox - wp->xoff,
          j, ri->nx, ri->px, py, &defaults, palette);
    }
  }

#ifdef ENABLE_SIXEL
  tty_draw_images(c, wp, s);
#endif
}

/* Draw the panes scrollbars */
static void
screen_redraw_draw_pane_scrollbars(struct screen_redraw_ctx *ctx)
{
  struct client   *c = ctx->c;
  struct window   *w = c->session->curw->window;
  struct window_pane  *wp;

  log_debug("%s: %s @%u", __func__, c->name, w->id);

  TAILQ_FOREACH(wp, &w->panes, entry) {
    if (window_pane_show_scrollbar(wp, ctx->pane_scrollbars) &&
        window_pane_visible(wp))
      screen_redraw_draw_pane_scrollbar(ctx, wp);
  }
}

/* Calculate position and size of pane scrollbar. */
void
screen_redraw_draw_pane_scrollbar(struct screen_redraw_ctx *ctx,
    struct window_pane *wp)
{
  struct screen *s = wp->screen;
  double     percent_view;
  u_int    sb = ctx->pane_scrollbars, total_height, sb_h = wp->sy;
  u_int    sb_pos = ctx->pane_scrollbars_pos, slider_h, slider_y;
  int    sb_w = wp->scrollbar_style.width;
  int    sb_pad = wp->scrollbar_style.pad;
  int    cm_y, cm_size, xoff = wp->xoff;
  int    sb_x, sb_y = (int)wp->yoff; /* sb top */

  if (window_pane_mode(wp) == WINDOW_PANE_NO_MODE) {
    if (sb == PANE_SCROLLBARS_MODAL)
      return;
    /* Show slider at the bottom of the scrollbar. */
    total_height = screen_size_y(s) + screen_hsize(s);
    percent_view = (double)sb_h / total_height;
    slider_h = (double)sb_h * percent_view;
    slider_y = sb_h - slider_h;
  } else {
    if (TAILQ_FIRST(&wp->modes) == NULL)
      return;
    if (window_copy_get_current_offset(wp, &cm_y, &cm_size) == 0)
      return;
    total_height = cm_size + sb_h;
    percent_view = (double)sb_h / (cm_size + sb_h);
    slider_h = (double)sb_h * percent_view;
    slider_y = (sb_h + 1) * ((double)cm_y / (total_height));
  }

  if (sb_pos == PANE_SCROLLBARS_LEFT)
    sb_x = xoff - sb_w - sb_pad;
  else
    sb_x = xoff + wp->sx;

  if (slider_h < 1)
    slider_h = 1;
  if (slider_y >= sb_h)
    slider_y = sb_h - 1;

  screen_redraw_draw_scrollbar(ctx, wp, sb_pos, sb_x, sb_y, sb_h,
      slider_h, slider_y);

  /* Store current position and height of the slider */
  wp->sb_slider_y = slider_y;  /* top of slider y pos in scrollbar */
  wp->sb_slider_h = slider_h;  /* height of slider */
}

/* Draw pane scrollbar. */
static void
screen_redraw_draw_scrollbar(struct screen_redraw_ctx *ctx,
    struct window_pane *wp, int sb_pos, int sb_x, int sb_y, u_int sb_h,
    u_int slider_h, u_int slider_y)
{
  struct client   *c = ctx->c;
  struct tty    *tty = &c->tty;
  struct grid_cell   gc, slgc, *gcp;
  struct style    *sb_style = &wp->scrollbar_style;
  u_int      i, j, imin = 0, jmin = 0, imax, jmax;
  u_int      sb_w = sb_style->width, sb_pad = sb_style->pad;
  int      px, py, wx, wy, ox, oy, sx, sy, sb_tty_y;
  int      xoff = wp->xoff;
  int      yoff = wp->yoff;
  int      sb_wy = sb_y; /* window coordinates */
  struct visible_ranges *r;

  /*
   * Size and offset of window relative to tty. Status at top offsets
   * window downward.
   */
  sx = ctx->sx;
  sy = tty->sy - ctx->statuslines;
  ox = ctx->ox;
  oy = ctx->oy;
  if (ctx->statustop) {
    sb_y += ctx->statuslines; /* tty coordinates */
    sy += ctx->statuslines;
  }

  gc = sb_style->gc;
  memcpy(&slgc, &gc, sizeof slgc);
  slgc.fg = gc.bg;
  slgc.bg = gc.fg;

  if (sb_x + (int)sb_w < 0 || sb_x >= sx || sb_y >= sy) {
    /* Whole scrollbar is off screen. */
    return;
  }
  if (sb_x < 0) {
    /* Part of scrollbar on screen. */
    imin = - sb_x;
  }
  imax = sb_w + sb_pad;
  if ((int)imax + sb_x > sx) {
    if (sb_x > sx) {
      /* Whole scrollbar off screen. */
      return;
    }
    imax = sx - sb_x;
  }
  jmax = sb_h;
  if ((int)jmax + sb_y > sy) {
    if (sb_y >= sy)
      return;
    jmax = sy - sb_y;
  }

  /*
   * sb_y is in tty coordinate (window coord + statuslines when
   * statustop). Subtract the pan offset oy to get the tty row.
   */
  sb_tty_y = sb_y - oy; /* scrollbar top in tty coordinates */
  if (sb_tty_y > (int)sy) {
    /* Whole scrollbar is off screen. */
    return;
  }
  if (sb_tty_y < 0) {
    /* Scrollbar starts above visible area; skip those rows. */
    jmin = -sb_tty_y;
  }
  if (sb_tty_y + (int)sb_h <= 0) {
    /* Whole scrollbar above visible area. */
    return;
  }
  jmax = sb_h;
  if (sb_tty_y + (int)jmax > (int)sy) {
    /* Clip to height of tty. */
    jmax = sy - sb_tty_y;
  }

  for (j = jmin; j < jmax; j++) {
    wy = sb_wy + j; /* window y coordinate */
    py = sb_tty_y + j; /* tty y coordinate */
    r = tty_check_overlay_range(tty, sb_x, wy, imax);
    r = screen_redraw_get_visible_ranges(wp, sb_x, wy, imax, r);
    for (i = imin; i < imax; i++) {
      px = sb_x + ox + i; /* tty x coordinate */
      wx = sb_x + i; /* window x coordinate */
      if (wx < xoff - (int)sb_w - (int)sb_pad ||
          px >= sx || px < 0 ||
          wy < yoff - 1 ||
          py >= sy || py < 0 ||
          !screen_redraw_is_visible(r, wx))
        continue;
      tty_cursor(tty, px, py);
      if ((sb_pos == PANE_SCROLLBARS_LEFT &&
          i >= sb_w && i < sb_w + sb_pad) ||
          (sb_pos == PANE_SCROLLBARS_RIGHT &&
          i < sb_pad)) {
        tty_cell(tty, &grid_default_cell,
            &grid_default_cell, NULL, NULL);
      } else {
        if (j >= slider_y && j < slider_y + slider_h)
          gcp = &slgc;
        else
          gcp = &gc;
        tty_cell(tty, gcp, &grid_default_cell, NULL,
            NULL);
      }
    }
  }
}

Coverage Report

Created: 2026-06-10 06:31