/src/tmux/tty.c

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/* $OpenBSD$ */

/*
 * 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 <sys/ioctl.h>

#include <netinet/in.h>

#include <curses.h>
#include <errno.h>
#include <fcntl.h>
#include <resolv.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

#include "tmux.h"

static int  tty_log_fd = -1;

static void tty_set_italics(struct tty *);
static int  tty_try_colour(struct tty *, int, const char *);
static void tty_force_cursor_colour(struct tty *, int);
static void tty_cursor_pane(struct tty *, const struct tty_ctx *, u_int,
        u_int);
static void tty_cursor_pane_unless_wrap(struct tty *,
        const struct tty_ctx *, u_int, u_int);
static void tty_invalidate(struct tty *);
static void tty_colours(struct tty *, const struct grid_cell *);
static void tty_check_fg(struct tty *, struct colour_palette *,
            struct grid_cell *);
static void tty_check_bg(struct tty *, struct colour_palette *,
            struct grid_cell *);
static void tty_check_us(struct tty *, struct colour_palette *,
            struct grid_cell *);
static void tty_colours_fg(struct tty *, const struct grid_cell *);
static void tty_colours_bg(struct tty *, const struct grid_cell *);
static void tty_colours_us(struct tty *, const struct grid_cell *);

static void tty_region_pane(struct tty *, const struct tty_ctx *, u_int,
        u_int);
static void tty_region(struct tty *, u_int, u_int);
static void tty_margin_pane(struct tty *, const struct tty_ctx *);
static void tty_margin(struct tty *, u_int, u_int);
static int  tty_large_region(struct tty *, const struct tty_ctx *);
static int  tty_fake_bce(const struct tty *, const struct grid_cell *,
        u_int);
static void tty_redraw_region(struct tty *, const struct tty_ctx *);
static void tty_emulate_repeat(struct tty *, enum tty_code_code,
        enum tty_code_code, u_int);
static void tty_repeat_space(struct tty *, u_int);
static void tty_draw_pane(struct tty *, const struct tty_ctx *, u_int);
static void tty_default_attributes(struct tty *, const struct grid_cell *,
        struct colour_palette *, u_int, struct hyperlinks *);
static int  tty_check_overlay(struct tty *, u_int, u_int);
static void tty_check_overlay_range(struct tty *, u_int, u_int, u_int,
        struct overlay_ranges *);

#ifdef ENABLE_SIXEL
static void tty_write_one(void (*)(struct tty *, const struct tty_ctx *),
        struct client *, struct tty_ctx *);
#endif

#define tty_use_margin(tty) \
  (tty->term->flags & TERM_DECSLRM)
#define tty_full_width(tty, ctx) \
  ((ctx)->xoff == 0 && (ctx)->sx >= (tty)->sx)

#define TTY_BLOCK_INTERVAL (100000 /* 100 milliseconds */)
#define TTY_BLOCK_START(tty) (1 + ((tty)->sx * (tty)->sy) * 8)
#define TTY_BLOCK_STOP(tty) (1 + ((tty)->sx * (tty)->sy) / 8)

#define TTY_QUERY_TIMEOUT 5
#define TTY_REQUEST_LIMIT 30

void
tty_create_log(void)
{
  char  name[64];

  xsnprintf(name, sizeof name, "tmux-out-%ld.log", (long)getpid());

  tty_log_fd = open(name, O_WRONLY|O_CREAT|O_TRUNC, 0644);
  if (tty_log_fd != -1 && fcntl(tty_log_fd, F_SETFD, FD_CLOEXEC) == -1)
    fatal("fcntl failed");
}

int
tty_init(struct tty *tty, struct client *c)
{
  if (!isatty(c->fd))
    return (-1);

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

  tty->cstyle = SCREEN_CURSOR_DEFAULT;
  tty->ccolour = -1;
  tty->fg = tty->bg = -1;

  if (tcgetattr(c->fd, &tty->tio) != 0)
    return (-1);
  return (0);
}

void
tty_resize(struct tty *tty)
{
  struct client *c = tty->client;
  struct winsize   ws;
  u_int    sx, sy, xpixel, ypixel;

  if (ioctl(c->fd, TIOCGWINSZ, &ws) != -1) {
    sx = ws.ws_col;
    if (sx == 0) {
      sx = 80;
      xpixel = 0;
    } else
      xpixel = ws.ws_xpixel / sx;
    sy = ws.ws_row;
    if (sy == 0) {
      sy = 24;
      ypixel = 0;
    } else
      ypixel = ws.ws_ypixel / sy;
  } else {
    sx = 80;
    sy = 24;
    xpixel = 0;
    ypixel = 0;
  }
  log_debug("%s: %s now %ux%u (%ux%u)", __func__, c->name, sx, sy,
      xpixel, ypixel);
  tty_set_size(tty, sx, sy, xpixel, ypixel);
  tty_invalidate(tty);
}

void
tty_set_size(struct tty *tty, u_int sx, u_int sy, u_int xpixel, u_int ypixel)
{
  tty->sx = sx;
  tty->sy = sy;
  tty->xpixel = xpixel;
  tty->ypixel = ypixel;
}

static void
tty_read_callback(__unused int fd, __unused short events, void *data)
{
  struct tty  *tty = data;
  struct client *c = tty->client;
  const char  *name = c->name;
  size_t     size = EVBUFFER_LENGTH(tty->in);
  int    nread;

  nread = evbuffer_read(tty->in, c->fd, -1);
  if (nread == 0 || nread == -1) {
    if (nread == 0)
      log_debug("%s: read closed", name);
    else
      log_debug("%s: read error: %s", name, strerror(errno));
    event_del(&tty->event_in);
    server_client_lost(tty->client);
    return;
  }
  log_debug("%s: read %d bytes (already %zu)", name, nread, size);

  while (tty_keys_next(tty))
    ;
}

static void
tty_timer_callback(__unused int fd, __unused short events, void *data)
{
  struct tty  *tty = data;
  struct client *c = tty->client;
  struct timeval   tv = { .tv_usec = TTY_BLOCK_INTERVAL };

  log_debug("%s: %zu discarded", c->name, tty->discarded);

  c->flags |= CLIENT_ALLREDRAWFLAGS;
  c->discarded += tty->discarded;

  if (tty->discarded < TTY_BLOCK_STOP(tty)) {
    tty->flags &= ~TTY_BLOCK;
    tty_invalidate(tty);
    return;
  }
  tty->discarded = 0;
  evtimer_add(&tty->timer, &tv);
}

static int
tty_block_maybe(struct tty *tty)
{
  struct client *c = tty->client;
  size_t     size = EVBUFFER_LENGTH(tty->out);
  struct timeval   tv = { .tv_usec = TTY_BLOCK_INTERVAL };

  if (size == 0)
    tty->flags &= ~TTY_NOBLOCK;
  else if (tty->flags & TTY_NOBLOCK)
    return (0);

  if (size < TTY_BLOCK_START(tty))
    return (0);

  if (tty->flags & TTY_BLOCK)
    return (1);
  tty->flags |= TTY_BLOCK;

  log_debug("%s: can't keep up, %zu discarded", c->name, size);

  evbuffer_drain(tty->out, size);
  c->discarded += size;

  tty->discarded = 0;
  evtimer_add(&tty->timer, &tv);
  return (1);
}

static void
tty_write_callback(__unused int fd, __unused short events, void *data)
{
  struct tty  *tty = data;
  struct client *c = tty->client;
  size_t     size = EVBUFFER_LENGTH(tty->out);
  int    nwrite;

  nwrite = evbuffer_write(tty->out, c->fd);
  if (nwrite == -1)
    return;
  log_debug("%s: wrote %d bytes (of %zu)", c->name, nwrite, size);

  if (c->redraw > 0) {
    if ((size_t)nwrite >= c->redraw)
      c->redraw = 0;
    else
      c->redraw -= nwrite;
    log_debug("%s: waiting for redraw, %zu bytes left", c->name,
        c->redraw);
  } else if (tty_block_maybe(tty))
    return;

  if (EVBUFFER_LENGTH(tty->out) != 0)
    event_add(&tty->event_out, NULL);
}

int
tty_open(struct tty *tty, char **cause)
{
  struct client *c = tty->client;

  tty->term = tty_term_create(tty, c->term_name, c->term_caps,
      c->term_ncaps, &c->term_features, cause);
  if (tty->term == NULL) {
    tty_close(tty);
    return (-1);
  }
  tty->flags |= TTY_OPENED;

  tty->flags &= ~(TTY_NOCURSOR|TTY_FREEZE|TTY_BLOCK|TTY_TIMER);

  event_set(&tty->event_in, c->fd, EV_PERSIST|EV_READ,
      tty_read_callback, tty);
  tty->in = evbuffer_new();
  if (tty->in == NULL)
    fatal("out of memory");

  event_set(&tty->event_out, c->fd, EV_WRITE, tty_write_callback, tty);
  tty->out = evbuffer_new();
  if (tty->out == NULL)
    fatal("out of memory");

  evtimer_set(&tty->timer, tty_timer_callback, tty);

  tty_start_tty(tty);
  tty_keys_build(tty);

  return (0);
}

static void
tty_start_timer_callback(__unused int fd, __unused short events, void *data)
{
  struct tty  *tty = data;
  struct client *c = tty->client;

  log_debug("%s: start timer fired", c->name);
  if ((tty->flags & (TTY_HAVEDA|TTY_HAVEDA2|TTY_HAVEXDA)) == 0)
    tty_update_features(tty);
  tty->flags |= TTY_ALL_REQUEST_FLAGS;
}

void
tty_start_tty(struct tty *tty)
{
  struct client *c = tty->client;
  struct termios   tio;
  struct timeval   tv = { .tv_sec = TTY_QUERY_TIMEOUT };

  setblocking(c->fd, 0);
  event_add(&tty->event_in, NULL);

  memcpy(&tio, &tty->tio, sizeof tio);
  tio.c_iflag &= ~(IXON|IXOFF|ICRNL|INLCR|IGNCR|IMAXBEL|ISTRIP);
  tio.c_iflag |= IGNBRK;
  tio.c_oflag &= ~(OPOST|ONLCR|OCRNL|ONLRET);
  tio.c_lflag &= ~(IEXTEN|ICANON|ECHO|ECHOE|ECHONL|ECHOCTL|ECHOPRT|
      ECHOKE|ISIG);
  tio.c_cc[VMIN] = 1;
  tio.c_cc[VTIME] = 0;
  if (tcsetattr(c->fd, TCSANOW, &tio) == 0)
    tcflush(c->fd, TCOFLUSH);

  tty_putcode(tty, TTYC_SMCUP);

  tty_putcode(tty, TTYC_SMKX);
  tty_putcode(tty, TTYC_CLEAR);

  if (tty_acs_needed(tty)) {
    log_debug("%s: using capabilities for ACS", c->name);
    tty_putcode(tty, TTYC_ENACS);
  } else
    log_debug("%s: using UTF-8 for ACS", c->name);

  tty_putcode(tty, TTYC_CNORM);
  if (tty_term_has(tty->term, TTYC_KMOUS)) {
    tty_puts(tty, "\033[?1000l\033[?1002l\033[?1003l");
    tty_puts(tty, "\033[?1006l\033[?1005l");
  }
  if (tty_term_has(tty->term, TTYC_ENBP))
    tty_putcode(tty, TTYC_ENBP);

  evtimer_set(&tty->start_timer, tty_start_timer_callback, tty);
  evtimer_add(&tty->start_timer, &tv);

  tty->flags |= TTY_STARTED;
  tty_invalidate(tty);

  if (tty->ccolour != -1)
    tty_force_cursor_colour(tty, -1);

  tty->mouse_drag_flag = 0;
  tty->mouse_drag_update = NULL;
  tty->mouse_drag_release = NULL;
}

void
tty_send_requests(struct tty *tty)
{
  if (~tty->flags & TTY_STARTED)
    return;

  if (tty->term->flags & TERM_VT100LIKE) {
    if (~tty->term->flags & TTY_HAVEDA)
      tty_puts(tty, "\033[c");
    if (~tty->flags & TTY_HAVEDA2)
      tty_puts(tty, "\033[>c");
    if (~tty->flags & TTY_HAVEXDA)
      tty_puts(tty, "\033[>q");
    tty_puts(tty, "\033]10;?\033\\");
    tty_puts(tty, "\033]11;?\033\\");
  } else
    tty->flags |= TTY_ALL_REQUEST_FLAGS;
  tty->last_requests = time(NULL);
}

void
tty_repeat_requests(struct tty *tty)
{
  time_t  t = time(NULL);

  if (~tty->flags & TTY_STARTED)
    return;

  if (t - tty->last_requests <= TTY_REQUEST_LIMIT)
    return;
  tty->last_requests = t;

  if (tty->term->flags & TERM_VT100LIKE) {
    tty_puts(tty, "\033]10;?\033\\");
    tty_puts(tty, "\033]11;?\033\\");
  }
}

void
tty_stop_tty(struct tty *tty)
{
  struct client *c = tty->client;
  struct winsize   ws;

  if (!(tty->flags & TTY_STARTED))
    return;
  tty->flags &= ~TTY_STARTED;

  evtimer_del(&tty->start_timer);

  event_del(&tty->timer);
  tty->flags &= ~TTY_BLOCK;

  event_del(&tty->event_in);
  event_del(&tty->event_out);

  /*
   * Be flexible about error handling and try not kill the server just
   * because the fd is invalid. Things like ssh -t can easily leave us
   * with a dead tty.
   */
  if (ioctl(c->fd, TIOCGWINSZ, &ws) == -1)
    return;
  if (tcsetattr(c->fd, TCSANOW, &tty->tio) == -1)
    return;

  tty_raw(tty, tty_term_string_ii(tty->term, TTYC_CSR, 0, ws.ws_row - 1));
  if (tty_acs_needed(tty))
    tty_raw(tty, tty_term_string(tty->term, TTYC_RMACS));
  tty_raw(tty, tty_term_string(tty->term, TTYC_SGR0));
  tty_raw(tty, tty_term_string(tty->term, TTYC_RMKX));
  tty_raw(tty, tty_term_string(tty->term, TTYC_CLEAR));
  if (tty->cstyle != SCREEN_CURSOR_DEFAULT) {
    if (tty_term_has(tty->term, TTYC_SE))
      tty_raw(tty, tty_term_string(tty->term, TTYC_SE));
    else if (tty_term_has(tty->term, TTYC_SS))
      tty_raw(tty, tty_term_string_i(tty->term, TTYC_SS, 0));
  }
  if (tty->ccolour != -1)
    tty_raw(tty, tty_term_string(tty->term, TTYC_CR));

  tty_raw(tty, tty_term_string(tty->term, TTYC_CNORM));
  if (tty_term_has(tty->term, TTYC_KMOUS)) {
    tty_raw(tty, "\033[?1000l\033[?1002l\033[?1003l");
    tty_raw(tty, "\033[?1006l\033[?1005l");
  }
  if (tty_term_has(tty->term, TTYC_DSBP))
    tty_raw(tty, tty_term_string(tty->term, TTYC_DSBP));

  if (tty->term->flags & TERM_VT100LIKE)
    tty_raw(tty, "\033[?7727l");
  tty_raw(tty, tty_term_string(tty->term, TTYC_DSFCS));
  tty_raw(tty, tty_term_string(tty->term, TTYC_DSEKS));

  if (tty_use_margin(tty))
    tty_raw(tty, tty_term_string(tty->term, TTYC_DSMG));
  tty_raw(tty, tty_term_string(tty->term, TTYC_RMCUP));

  setblocking(c->fd, 1);
}

void
tty_close(struct tty *tty)
{
  if (event_initialized(&tty->key_timer))
    evtimer_del(&tty->key_timer);
  tty_stop_tty(tty);

  if (tty->flags & TTY_OPENED) {
    evbuffer_free(tty->in);
    event_del(&tty->event_in);
    evbuffer_free(tty->out);
    event_del(&tty->event_out);

    tty_term_free(tty->term);
    tty_keys_free(tty);

    tty->flags &= ~TTY_OPENED;
  }
}

void
tty_free(struct tty *tty)
{
  tty_close(tty);
}

void
tty_update_features(struct tty *tty)
{
  struct client *c = tty->client;

  if (tty_apply_features(tty->term, c->term_features))
    tty_term_apply_overrides(tty->term);

  if (tty_use_margin(tty))
    tty_putcode(tty, TTYC_ENMG);
  if (options_get_number(global_options, "extended-keys"))
    tty_puts(tty, tty_term_string(tty->term, TTYC_ENEKS));
  if (options_get_number(global_options, "focus-events"))
    tty_puts(tty, tty_term_string(tty->term, TTYC_ENFCS));
  if (tty->term->flags & TERM_VT100LIKE)
    tty_puts(tty, "\033[?7727h");

  /*
   * Features might have changed since the first draw during attach. For
   * example, this happens when DA responses are received.
   */
  server_redraw_client(c);

  tty_invalidate(tty);
}

void
tty_raw(struct tty *tty, const char *s)
{
  struct client *c = tty->client;
  ssize_t    n, slen;
  u_int    i;

  slen = strlen(s);
  for (i = 0; i < 5; i++) {
    n = write(c->fd, s, slen);
    if (n >= 0) {
      s += n;
      slen -= n;
      if (slen == 0)
        break;
    } else if (n == -1 && errno != EAGAIN)
      break;
    usleep(100);
  }
}

void
tty_putcode(struct tty *tty, enum tty_code_code code)
{
  tty_puts(tty, tty_term_string(tty->term, code));
}

void
tty_putcode_i(struct tty *tty, enum tty_code_code code, int a)
{
  if (a < 0)
    return;
  tty_puts(tty, tty_term_string_i(tty->term, code, a));
}

void
tty_putcode_ii(struct tty *tty, enum tty_code_code code, int a, int b)
{
  if (a < 0 || b < 0)
    return;
  tty_puts(tty, tty_term_string_ii(tty->term, code, a, b));
}

void
tty_putcode_iii(struct tty *tty, enum tty_code_code code, int a, int b, int c)
{
  if (a < 0 || b < 0 || c < 0)
    return;
  tty_puts(tty, tty_term_string_iii(tty->term, code, a, b, c));
}

void
tty_putcode_s(struct tty *tty, enum tty_code_code code, const char *a)
{
  if (a != NULL)
    tty_puts(tty, tty_term_string_s(tty->term, code, a));
}

void
tty_putcode_ss(struct tty *tty, enum tty_code_code code, const char *a,
    const char *b)
{
  if (a != NULL && b != NULL)
    tty_puts(tty, tty_term_string_ss(tty->term, code, a, b));
}

static void
tty_add(struct tty *tty, const char *buf, size_t len)
{
  struct client *c = tty->client;

  if (tty->flags & TTY_BLOCK) {
    tty->discarded += len;
    return;
  }

  evbuffer_add(tty->out, buf, len);
  log_debug("%s: %.*s", c->name, (int)len, buf);
  c->written += len;

  if (tty_log_fd != -1)
    write(tty_log_fd, buf, len);
  if (tty->flags & TTY_STARTED)
    event_add(&tty->event_out, NULL);
}

void
tty_puts(struct tty *tty, const char *s)
{
  if (*s != '\0')
    tty_add(tty, s, strlen(s));
}

void
tty_putc(struct tty *tty, u_char ch)
{
  const char  *acs;

  if ((tty->term->flags & TERM_NOAM) &&
      ch >= 0x20 && ch != 0x7f &&
      tty->cy == tty->sy - 1 &&
      tty->cx + 1 >= tty->sx)
    return;

  if (tty->cell.attr & GRID_ATTR_CHARSET) {
    acs = tty_acs_get(tty, ch);
    if (acs != NULL)
      tty_add(tty, acs, strlen(acs));
    else
      tty_add(tty, &ch, 1);
  } else
    tty_add(tty, &ch, 1);

  if (ch >= 0x20 && ch != 0x7f) {
    if (tty->cx >= tty->sx) {
      tty->cx = 1;
      if (tty->cy != tty->rlower)
        tty->cy++;

      /*
       * On !am terminals, force the cursor position to where
       * we think it should be after a line wrap - this means
       * it works on sensible terminals as well.
       */
      if (tty->term->flags & TERM_NOAM)
        tty_putcode_ii(tty, TTYC_CUP, tty->cy, tty->cx);
    } else
      tty->cx++;
  }
}

void
tty_putn(struct tty *tty, const void *buf, size_t len, u_int width)
{
  if ((tty->term->flags & TERM_NOAM) &&
      tty->cy == tty->sy - 1 &&
      tty->cx + len >= tty->sx)
    len = tty->sx - tty->cx - 1;

  tty_add(tty, buf, len);
  if (tty->cx + width > tty->sx) {
    tty->cx = (tty->cx + width) - tty->sx;
    if (tty->cx <= tty->sx)
      tty->cy++;
    else
      tty->cx = tty->cy = UINT_MAX;
  } else
    tty->cx += width;
}

static void
tty_set_italics(struct tty *tty)
{
  const char  *s;

  if (tty_term_has(tty->term, TTYC_SITM)) {
    s = options_get_string(global_options, "default-terminal");
    if (strcmp(s, "screen") != 0 && strncmp(s, "screen-", 7) != 0) {
      tty_putcode(tty, TTYC_SITM);
      return;
    }
  }
  tty_putcode(tty, TTYC_SMSO);
}

void
tty_set_title(struct tty *tty, const char *title)
{
  if (!tty_term_has(tty->term, TTYC_TSL) ||
      !tty_term_has(tty->term, TTYC_FSL))
    return;

  tty_putcode(tty, TTYC_TSL);
  tty_puts(tty, title);
  tty_putcode(tty, TTYC_FSL);
}

void
tty_set_path(struct tty *tty, const char *title)
{
  if (!tty_term_has(tty->term, TTYC_SWD) ||
      !tty_term_has(tty->term, TTYC_FSL))
    return;

  tty_putcode(tty, TTYC_SWD);
  tty_puts(tty, title);
  tty_putcode(tty, TTYC_FSL);
}

static void
tty_force_cursor_colour(struct tty *tty, int c)
{
  u_char  r, g, b;
  char  s[13];

  if (c != -1)
    c = colour_force_rgb(c);
  if (c == tty->ccolour)
    return;
  if (c == -1)
    tty_putcode(tty, TTYC_CR);
  else {
    colour_split_rgb(c, &r, &g, &b);
    xsnprintf(s, sizeof s, "rgb:%02hhx/%02hhx/%02hhx", r, g, b);
    tty_putcode_s(tty, TTYC_CS, s);
  }
  tty->ccolour = c;
}

static int
tty_update_cursor(struct tty *tty, int mode, struct screen *s)
{
  enum screen_cursor_style  cstyle;
  int       ccolour, changed, cmode = mode;

  /* Set cursor colour if changed. */
  if (s != NULL) {
    ccolour = s->ccolour;
    if (s->ccolour == -1)
      ccolour = s->default_ccolour;
    tty_force_cursor_colour(tty, ccolour);
  }

  /* If cursor is off, set as invisible. */
  if (~cmode & MODE_CURSOR) {
    if (tty->mode & MODE_CURSOR)
      tty_putcode(tty, TTYC_CIVIS);
    return (cmode);
  }

  /* Check if blinking or very visible flag changed or style changed. */
  if (s == NULL)
    cstyle = tty->cstyle;
  else {
    cstyle = s->cstyle;
    if (cstyle == SCREEN_CURSOR_DEFAULT) {
      if (~cmode & MODE_CURSOR_BLINKING_SET) {
        if (s->default_mode & MODE_CURSOR_BLINKING)
          cmode |= MODE_CURSOR_BLINKING;
        else
          cmode &= ~MODE_CURSOR_BLINKING;
      }
      cstyle = s->default_cstyle;
    }
  }

  /* If nothing changed, do nothing. */
  changed = cmode ^ tty->mode;
  if ((changed & CURSOR_MODES) == 0 && cstyle == tty->cstyle)
    return (cmode);

  /*
   * Set cursor style. If an explicit style has been set with DECSCUSR,
   * set it if supported, otherwise send cvvis for blinking styles.
   *
   * If no style, has been set (SCREEN_CURSOR_DEFAULT), then send cvvis
   * if either the blinking or very visible flags are set.
   */
  tty_putcode(tty, TTYC_CNORM);
  switch (cstyle) {
  case SCREEN_CURSOR_DEFAULT:
    if (tty->cstyle != SCREEN_CURSOR_DEFAULT) {
      if (tty_term_has(tty->term, TTYC_SE))
        tty_putcode(tty, TTYC_SE);
      else
        tty_putcode_i(tty, TTYC_SS, 0);
    }
    if (cmode & (MODE_CURSOR_BLINKING|MODE_CURSOR_VERY_VISIBLE))
      tty_putcode(tty, TTYC_CVVIS);
    break;
  case SCREEN_CURSOR_BLOCK:
    if (tty_term_has(tty->term, TTYC_SS)) {
      if (cmode & MODE_CURSOR_BLINKING)
        tty_putcode_i(tty, TTYC_SS, 1);
      else
        tty_putcode_i(tty, TTYC_SS, 2);
    } else if (cmode & MODE_CURSOR_BLINKING)
      tty_putcode(tty, TTYC_CVVIS);
    break;
  case SCREEN_CURSOR_UNDERLINE:
    if (tty_term_has(tty->term, TTYC_SS)) {
      if (cmode & MODE_CURSOR_BLINKING)
        tty_putcode_i(tty, TTYC_SS, 3);
      else
        tty_putcode_i(tty, TTYC_SS, 4);
    } else if (cmode & MODE_CURSOR_BLINKING)
      tty_putcode(tty, TTYC_CVVIS);
    break;
  case SCREEN_CURSOR_BAR:
    if (tty_term_has(tty->term, TTYC_SS)) {
      if (cmode & MODE_CURSOR_BLINKING)
        tty_putcode_i(tty, TTYC_SS, 5);
      else
        tty_putcode_i(tty, TTYC_SS, 6);
    } else if (cmode & MODE_CURSOR_BLINKING)
      tty_putcode(tty, TTYC_CVVIS);
    break;
  }
  tty->cstyle = cstyle;
  return (cmode);
 }

void
tty_update_mode(struct tty *tty, int mode, struct screen *s)
{
  struct tty_term *term = tty->term;
  struct client *c = tty->client;
  int    changed;

  if (tty->flags & TTY_NOCURSOR)
    mode &= ~MODE_CURSOR;

  if (tty_update_cursor(tty, mode, s) & MODE_CURSOR_BLINKING)
    mode |= MODE_CURSOR_BLINKING;
  else
    mode &= ~MODE_CURSOR_BLINKING;

  changed = mode ^ tty->mode;
  if (log_get_level() != 0 && changed != 0) {
    log_debug("%s: current mode %s", c->name,
        screen_mode_to_string(tty->mode));
    log_debug("%s: setting mode %s", c->name,
        screen_mode_to_string(mode));
  }

  if ((changed & ALL_MOUSE_MODES) && tty_term_has(term, TTYC_KMOUS)) {
    /*
     * If the mouse modes have changed, clear then all and apply
     * again. There are differences in how terminals track the
     * various bits.
     */
    tty_puts(tty, "\033[?1006l\033[?1000l\033[?1002l\033[?1003l");
    if (mode & ALL_MOUSE_MODES)
      tty_puts(tty, "\033[?1006h");
    if (mode & MODE_MOUSE_ALL)
      tty_puts(tty, "\033[?1000h\033[?1002h\033[?1003h");
    else if (mode & MODE_MOUSE_BUTTON)
      tty_puts(tty, "\033[?1000h\033[?1002h");
    else if (mode & MODE_MOUSE_STANDARD)
      tty_puts(tty, "\033[?1000h");
  }
  tty->mode = mode;
}

static void
tty_emulate_repeat(struct tty *tty, enum tty_code_code code,
    enum tty_code_code code1, u_int n)
{
  if (tty_term_has(tty->term, code))
    tty_putcode_i(tty, code, n);
  else {
    while (n-- > 0)
      tty_putcode(tty, code1);
  }
}

static void
tty_repeat_space(struct tty *tty, u_int n)
{
  static char s[500];

  if (*s != ' ')
    memset(s, ' ', sizeof s);

  while (n > sizeof s) {
    tty_putn(tty, s, sizeof s, sizeof s);
    n -= sizeof s;
  }
  if (n != 0)
    tty_putn(tty, s, n, n);
}

/* Is this window bigger than the terminal? */
int
tty_window_bigger(struct tty *tty)
{
  struct client *c = tty->client;
  struct window *w = c->session->curw->window;

  return (tty->sx < w->sx || tty->sy - status_line_size(c) < w->sy);
}

/* What offset should this window be drawn at? */
int
tty_window_offset(struct tty *tty, u_int *ox, u_int *oy, u_int *sx, u_int *sy)
{
  *ox = tty->oox;
  *oy = tty->ooy;
  *sx = tty->osx;
  *sy = tty->osy;

  return (tty->oflag);
}

/* What offset should this window be drawn at? */
static int
tty_window_offset1(struct tty *tty, u_int *ox, u_int *oy, u_int *sx, u_int *sy)
{
  struct client   *c = tty->client;
  struct window   *w = c->session->curw->window;
  struct window_pane  *wp = server_client_get_pane(c);
  u_int      cx, cy, lines;

  lines = status_line_size(c);

  if (tty->sx >= w->sx && tty->sy - lines >= w->sy) {
    *ox = 0;
    *oy = 0;
    *sx = w->sx;
    *sy = w->sy;

    c->pan_window = NULL;
    return (0);
  }

  *sx = tty->sx;
  *sy = tty->sy - lines;

  if (c->pan_window == w) {
    if (*sx >= w->sx)
      c->pan_ox = 0;
    else if (c->pan_ox + *sx > w->sx)
      c->pan_ox = w->sx - *sx;
    *ox = c->pan_ox;
    if (*sy >= w->sy)
      c->pan_oy = 0;
    else if (c->pan_oy + *sy > w->sy)
      c->pan_oy = w->sy - *sy;
    *oy = c->pan_oy;
    return (1);
  }

  if (~wp->screen->mode & MODE_CURSOR) {
    *ox = 0;
    *oy = 0;
  } else {
    cx = wp->xoff + wp->screen->cx;
    cy = wp->yoff + wp->screen->cy;

    if (cx < *sx)
      *ox = 0;
    else if (cx > w->sx - *sx)
      *ox = w->sx - *sx;
    else
      *ox = cx - *sx / 2;

    if (cy < *sy)
      *oy = 0;
    else if (cy > w->sy - *sy)
      *oy = w->sy - *sy;
    else
      *oy = cy - *sy / 2;
  }

  c->pan_window = NULL;
  return (1);
}

/* Update stored offsets for a window and redraw if necessary. */
void
tty_update_window_offset(struct window *w)
{
  struct client *c;

  TAILQ_FOREACH(c, &clients, entry) {
    if (c->session != NULL &&
        c->session->curw != NULL &&
        c->session->curw->window == w)
      tty_update_client_offset(c);
  }
}

/* Update stored offsets for a client and redraw if necessary. */
void
tty_update_client_offset(struct client *c)
{
  u_int ox, oy, sx, sy;

  if (~c->flags & CLIENT_TERMINAL)
    return;

  c->tty.oflag = tty_window_offset1(&c->tty, &ox, &oy, &sx, &sy);
  if (ox == c->tty.oox &&
      oy == c->tty.ooy &&
      sx == c->tty.osx &&
      sy == c->tty.osy)
    return;

  log_debug ("%s: %s offset has changed (%u,%u %ux%u -> %u,%u %ux%u)",
      __func__, c->name, c->tty.oox, c->tty.ooy, c->tty.osx, c->tty.osy,
      ox, oy, sx, sy);

  c->tty.oox = ox;
  c->tty.ooy = oy;
  c->tty.osx = sx;
  c->tty.osy = sy;

  c->flags |= (CLIENT_REDRAWWINDOW|CLIENT_REDRAWSTATUS);
}

/*
 * Is the region large enough to be worth redrawing once later rather than
 * probably several times now? Currently yes if it is more than 50% of the
 * pane.
 */
static int
tty_large_region(__unused struct tty *tty, const struct tty_ctx *ctx)
{
  return (ctx->orlower - ctx->orupper >= ctx->sy / 2);
}

/*
 * Return if BCE is needed but the terminal doesn't have it - it'll need to be
 * emulated.
 */
static int
tty_fake_bce(const struct tty *tty, const struct grid_cell *gc, u_int bg)
{
  if (tty_term_flag(tty->term, TTYC_BCE))
    return (0);
  if (!COLOUR_DEFAULT(bg) || !COLOUR_DEFAULT(gc->bg))
    return (1);
  return (0);
}

/*
 * Redraw scroll region using data from screen (already updated). Used when
 * CSR not supported, or window is a pane that doesn't take up the full
 * width of the terminal.
 */
static void
tty_redraw_region(struct tty *tty, const struct tty_ctx *ctx)
{
  struct client   *c = tty->client;
  u_int      i;

  /*
   * If region is large, schedule a redraw. In most cases this is likely
   * to be followed by some more scrolling.
   */
  if (tty_large_region(tty, ctx)) {
    log_debug("%s: %s large redraw", __func__, c->name);
    ctx->redraw_cb(ctx);
    return;
  }

  for (i = ctx->orupper; i <= ctx->orlower; i++)
    tty_draw_pane(tty, ctx, i);
}

/* Is this position visible in the pane? */
static int
tty_is_visible(__unused struct tty *tty, const struct tty_ctx *ctx, u_int px,
    u_int py, u_int nx, u_int ny)
{
  u_int xoff = ctx->rxoff + px, yoff = ctx->ryoff + py;

  if (!ctx->bigger)
    return (1);

  if (xoff + nx <= ctx->wox || xoff >= ctx->wox + ctx->wsx ||
      yoff + ny <= ctx->woy || yoff >= ctx->woy + ctx->wsy)
    return (0);
  return (1);
}

/* Clamp line position to visible part of pane. */
static int
tty_clamp_line(struct tty *tty, const struct tty_ctx *ctx, u_int px, u_int py,
    u_int nx, u_int *i, u_int *x, u_int *rx, u_int *ry)
{
  u_int xoff = ctx->rxoff + px;

  if (!tty_is_visible(tty, ctx, px, py, nx, 1))
    return (0);
  *ry = ctx->yoff + py - ctx->woy;

  if (xoff >= ctx->wox && xoff + nx <= ctx->wox + ctx->wsx) {
    /* All visible. */
    *i = 0;
    *x = ctx->xoff + px - ctx->wox;
    *rx = nx;
  } else if (xoff < ctx->wox && xoff + nx > ctx->wox + ctx->wsx) {
    /* Both left and right not visible. */
    *i = ctx->wox;
    *x = 0;
    *rx = ctx->wsx;
  } else if (xoff < ctx->wox) {
    /* Left not visible. */
    *i = ctx->wox - (ctx->xoff + px);
    *x = 0;
    *rx = nx - *i;
  } else {
    /* Right not visible. */
    *i = 0;
    *x = (ctx->xoff + px) - ctx->wox;
    *rx = ctx->wsx - *x;
  }
  if (*rx > nx)
    fatalx("%s: x too big, %u > %u", __func__, *rx, nx);

  return (1);
}

/* Clear a line. */
static void
tty_clear_line(struct tty *tty, const struct grid_cell *defaults, u_int py,
    u_int px, u_int nx, u_int bg)
{
  struct client   *c = tty->client;
  struct overlay_ranges  r;
  u_int      i;

  log_debug("%s: %s, %u at %u,%u", __func__, c->name, nx, px, py);

  /* Nothing to clear. */
  if (nx == 0)
    return;

  /* If genuine BCE is available, can try escape sequences. */
  if (c->overlay_check == NULL && !tty_fake_bce(tty, defaults, bg)) {
    /* Off the end of the line, use EL if available. */
    if (px + nx >= tty->sx && tty_term_has(tty->term, TTYC_EL)) {
      tty_cursor(tty, px, py);
      tty_putcode(tty, TTYC_EL);
      return;
    }

    /* At the start of the line. Use EL1. */
    if (px == 0 && tty_term_has(tty->term, TTYC_EL1)) {
      tty_cursor(tty, px + nx - 1, py);
      tty_putcode(tty, TTYC_EL1);
      return;
    }

    /* Section of line. Use ECH if possible. */
    if (tty_term_has(tty->term, TTYC_ECH)) {
      tty_cursor(tty, px, py);
      tty_putcode_i(tty, TTYC_ECH, nx);
      return;
    }
  }

  /*
   * Couldn't use an escape sequence, use spaces. Clear only the visible
   * bit if there is an overlay.
   */
  tty_check_overlay_range(tty, px, py, nx, &r);
  for (i = 0; i < OVERLAY_MAX_RANGES; i++) {
    if (r.nx[i] == 0)
      continue;
    tty_cursor(tty, r.px[i], py);
    tty_repeat_space(tty, r.nx[i]);
  }
}

/* Clear a line, adjusting to visible part of pane. */
static void
tty_clear_pane_line(struct tty *tty, const struct tty_ctx *ctx, u_int py,
    u_int px, u_int nx, u_int bg)
{
  struct client *c = tty->client;
  u_int    i, x, rx, ry;

  log_debug("%s: %s, %u at %u,%u", __func__, c->name, nx, px, py);

  if (tty_clamp_line(tty, ctx, px, py, nx, &i, &x, &rx, &ry))
    tty_clear_line(tty, &ctx->defaults, ry, x, rx, bg);
}

/* Clamp area position to visible part of pane. */
static int
tty_clamp_area(struct tty *tty, const struct tty_ctx *ctx, u_int px, u_int py,
    u_int nx, u_int ny, u_int *i, u_int *j, u_int *x, u_int *y, u_int *rx,
    u_int *ry)
{
  u_int xoff = ctx->rxoff + px, yoff = ctx->ryoff + py;

  if (!tty_is_visible(tty, ctx, px, py, nx, ny))
    return (0);

  if (xoff >= ctx->wox && xoff + nx <= ctx->wox + ctx->wsx) {
    /* All visible. */
    *i = 0;
    *x = ctx->xoff + px - ctx->wox;
    *rx = nx;
  } else if (xoff < ctx->wox && xoff + nx > ctx->wox + ctx->wsx) {
    /* Both left and right not visible. */
    *i = ctx->wox;
    *x = 0;
    *rx = ctx->wsx;
  } else if (xoff < ctx->wox) {
    /* Left not visible. */
    *i = ctx->wox - (ctx->xoff + px);
    *x = 0;
    *rx = nx - *i;
  } else {
    /* Right not visible. */
    *i = 0;
    *x = (ctx->xoff + px) - ctx->wox;
    *rx = ctx->wsx - *x;
  }
  if (*rx > nx)
    fatalx("%s: x too big, %u > %u", __func__, *rx, nx);

  if (yoff >= ctx->woy && yoff + ny <= ctx->woy + ctx->wsy) {
    /* All visible. */
    *j = 0;
    *y = ctx->yoff + py - ctx->woy;
    *ry = ny;
  } else if (yoff < ctx->woy && yoff + ny > ctx->woy + ctx->wsy) {
    /* Both top and bottom not visible. */
    *j = ctx->woy;
    *y = 0;
    *ry = ctx->wsy;
  } else if (yoff < ctx->woy) {
    /* Top not visible. */
    *j = ctx->woy - (ctx->yoff + py);
    *y = 0;
    *ry = ny - *j;
  } else {
    /* Bottom not visible. */
    *j = 0;
    *y = (ctx->yoff + py) - ctx->woy;
    *ry = ctx->wsy - *y;
  }
  if (*ry > ny)
    fatalx("%s: y too big, %u > %u", __func__, *ry, ny);

  return (1);
}

/* Clear an area, adjusting to visible part of pane. */
static void
tty_clear_area(struct tty *tty, const struct grid_cell *defaults, u_int py,
    u_int ny, u_int px, u_int nx, u_int bg)
{
  struct client *c = tty->client;
  u_int    yy;
  char     tmp[64];

  log_debug("%s: %s, %u,%u at %u,%u", __func__, c->name, nx, ny, px, py);

  /* Nothing to clear. */
  if (nx == 0 || ny == 0)
    return;

  /* If genuine BCE is available, can try escape sequences. */
  if (c->overlay_check == NULL && !tty_fake_bce(tty, defaults, bg)) {
    /* Use ED if clearing off the bottom of the terminal. */
    if (px == 0 &&
        px + nx >= tty->sx &&
        py + ny >= tty->sy &&
        tty_term_has(tty->term, TTYC_ED)) {
      tty_cursor(tty, 0, py);
      tty_putcode(tty, TTYC_ED);
      return;
    }

    /*
     * On VT420 compatible terminals we can use DECFRA if the
     * background colour isn't default (because it doesn't work
     * after SGR 0).
     */
    if ((tty->term->flags & TERM_DECFRA) && !COLOUR_DEFAULT(bg)) {
      xsnprintf(tmp, sizeof tmp, "\033[32;%u;%u;%u;%u$x",
          py + 1, px + 1, py + ny, px + nx);
      tty_puts(tty, tmp);
      return;
    }

    /* Full lines can be scrolled away to clear them. */
    if (px == 0 &&
        px + nx >= tty->sx &&
        ny > 2 &&
        tty_term_has(tty->term, TTYC_CSR) &&
        tty_term_has(tty->term, TTYC_INDN)) {
      tty_region(tty, py, py + ny - 1);
      tty_margin_off(tty);
      tty_putcode_i(tty, TTYC_INDN, ny);
      return;
    }

    /*
     * If margins are supported, can just scroll the area off to
     * clear it.
     */
    if (nx > 2 &&
        ny > 2 &&
        tty_term_has(tty->term, TTYC_CSR) &&
        tty_use_margin(tty) &&
        tty_term_has(tty->term, TTYC_INDN)) {
      tty_region(tty, py, py + ny - 1);
      tty_margin(tty, px, px + nx - 1);
      tty_putcode_i(tty, TTYC_INDN, ny);
      return;
    }
  }

  /* Couldn't use an escape sequence, loop over the lines. */
  for (yy = py; yy < py + ny; yy++)
    tty_clear_line(tty, defaults, yy, px, nx, bg);
}

/* Clear an area in a pane. */
static void
tty_clear_pane_area(struct tty *tty, const struct tty_ctx *ctx, u_int py,
    u_int ny, u_int px, u_int nx, u_int bg)
{
  u_int i, j, x, y, rx, ry;

  if (tty_clamp_area(tty, ctx, px, py, nx, ny, &i, &j, &x, &y, &rx, &ry))
    tty_clear_area(tty, &ctx->defaults, y, ry, x, rx, bg);
}

static void
tty_draw_pane(struct tty *tty, const struct tty_ctx *ctx, u_int py)
{
  struct screen *s = ctx->s;
  u_int    nx = ctx->sx, i, x, rx, ry;

  log_debug("%s: %s %u %d", __func__, tty->client->name, py, ctx->bigger);

  if (!ctx->bigger) {
    tty_draw_line(tty, s, 0, py, nx, ctx->xoff, ctx->yoff + py,
        &ctx->defaults, ctx->palette);
    return;
  }
  if (tty_clamp_line(tty, ctx, 0, py, nx, &i, &x, &rx, &ry)) {
    tty_draw_line(tty, s, i, py, rx, x, ry, &ctx->defaults,
        ctx->palette);
  }
}

static const struct grid_cell *
tty_check_codeset(struct tty *tty, const struct grid_cell *gc)
{
  static struct grid_cell new;
  int     c;

  /* Characters less than 0x7f are always fine, no matter what. */
  if (gc->data.size == 1 && *gc->data.data < 0x7f)
    return (gc);

  /* UTF-8 terminal and a UTF-8 character - fine. */
  if (tty->client->flags & CLIENT_UTF8)
    return (gc);
  memcpy(&new, gc, sizeof new);

  /* See if this can be mapped to an ACS character. */
  c = tty_acs_reverse_get(tty, gc->data.data, gc->data.size);
  if (c != -1) {
    utf8_set(&new.data, c);
    new.attr |= GRID_ATTR_CHARSET;
    return (&new);
  }

  /* Replace by the right number of underscores. */
  new.data.size = gc->data.width;
  if (new.data.size > UTF8_SIZE)
    new.data.size = UTF8_SIZE;
  memset(new.data.data, '_', new.data.size);
  return (&new);
}

/*
 * Check if a single character is obstructed by the overlay and return a
 * boolean.
 */
static int
tty_check_overlay(struct tty *tty, u_int px, u_int py)
{
  struct overlay_ranges r;

  /*
   * A unit width range will always return nx[2] == 0 from a check, even
   * with multiple overlays, so it's sufficient to check just the first
   * two entries.
   */
  tty_check_overlay_range(tty, px, py, 1, &r);
  if (r.nx[0] + r.nx[1] == 0)
    return (0);
  return (1);
}

/* Return parts of the input range which are visible. */
static void
tty_check_overlay_range(struct tty *tty, u_int px, u_int py, u_int nx,
    struct overlay_ranges *r)
{
  struct client *c = tty->client;

  if (c->overlay_check == NULL) {
    r->px[0] = px;
    r->nx[0] = nx;
    r->px[1] = 0;
    r->nx[1] = 0;
    r->px[2] = 0;
    r->nx[2] = 0;
    return;
  }

  c->overlay_check(c, c->overlay_data, px, py, nx, r);
}

void
tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
    u_int atx, u_int aty, const struct grid_cell *defaults,
    struct colour_palette *palette)
{
  struct grid   *gd = s->grid;
  struct grid_cell   gc, last;
  const struct grid_cell  *gcp;
  struct grid_line  *gl;
  struct client   *c = tty->client;
  struct overlay_ranges  r;
  u_int      i, j, ux, sx, width, hidden, eux, nxx;
  u_int      cellsize;
  int      flags, cleared = 0, wrapped = 0;
  char       buf[512];
  size_t       len;

  log_debug("%s: px=%u py=%u nx=%u atx=%u aty=%u", __func__,
      px, py, nx, atx, aty);
  log_debug("%s: defaults: fg=%d, bg=%d", __func__, defaults->fg,
      defaults->bg);

  /*
   * py is the line in the screen to draw.
   * px is the start x and nx is the width to draw.
   * atx,aty is the line on the terminal to draw it.
   */

  flags = (tty->flags & TTY_NOCURSOR);
  tty->flags |= TTY_NOCURSOR;
  tty_update_mode(tty, tty->mode, s);

  tty_region_off(tty);
  tty_margin_off(tty);

  /*
   * Clamp the width to cellsize - note this is not cellused, because
   * there may be empty background cells after it (from BCE).
   */
  sx = screen_size_x(s);
  if (nx > sx)
    nx = sx;
  cellsize = grid_get_line(gd, gd->hsize + py)->cellsize;
  if (sx > cellsize)
    sx = cellsize;
  if (sx > tty->sx)
    sx = tty->sx;
  if (sx > nx)
    sx = nx;
  ux = 0;

  if (py == 0)
    gl = NULL;
  else
    gl = grid_get_line(gd, gd->hsize + py - 1);
  if (gl == NULL ||
      (~gl->flags & GRID_LINE_WRAPPED) ||
      atx != 0 ||
      tty->cx < tty->sx ||
      nx < tty->sx) {
    if (nx < tty->sx &&
        atx == 0 &&
        px + sx != nx &&
        tty_term_has(tty->term, TTYC_EL1) &&
        !tty_fake_bce(tty, defaults, 8) &&
        c->overlay_check == NULL) {
      tty_default_attributes(tty, defaults, palette, 8,
          s->hyperlinks);
      tty_cursor(tty, nx - 1, aty);
      tty_putcode(tty, TTYC_EL1);
      cleared = 1;
    }
  } else {
    log_debug("%s: wrapped line %u", __func__, aty);
    wrapped = 1;
  }

  memcpy(&last, &grid_default_cell, sizeof last);
  len = 0;
  width = 0;

  for (i = 0; i < sx; i++) {
    grid_view_get_cell(gd, px + i, py, &gc);
    gcp = tty_check_codeset(tty, &gc);
    if (len != 0 &&
        (!tty_check_overlay(tty, atx + ux + width, aty) ||
        (gcp->attr & GRID_ATTR_CHARSET) ||
        gcp->flags != last.flags ||
        gcp->attr != last.attr ||
        gcp->fg != last.fg ||
        gcp->bg != last.bg ||
        gcp->us != last.us ||
        gcp->link != last.link ||
        ux + width + gcp->data.width > nx ||
        (sizeof buf) - len < gcp->data.size)) {
      tty_attributes(tty, &last, defaults, palette,
          s->hyperlinks);
      if (last.flags & GRID_FLAG_CLEARED) {
        log_debug("%s: %zu cleared", __func__, len);
        tty_clear_line(tty, defaults, aty, atx + ux,
            width, last.bg);
      } else {
        if (!wrapped || atx != 0 || ux != 0)
          tty_cursor(tty, atx + ux, aty);
        tty_putn(tty, buf, len, width);
      }
      ux += width;

      len = 0;
      width = 0;
      wrapped = 0;
    }

    if (gcp->flags & GRID_FLAG_SELECTED)
      screen_select_cell(s, &last, gcp);
    else
      memcpy(&last, gcp, sizeof last);

    tty_check_overlay_range(tty, atx + ux, aty, gcp->data.width,
        &r);
    hidden = 0;
    for (j = 0; j < OVERLAY_MAX_RANGES; j++)
      hidden += r.nx[j];
    hidden = gcp->data.width - hidden;
    if (hidden != 0 && hidden == gcp->data.width) {
      if (~gcp->flags & GRID_FLAG_PADDING)
        ux += gcp->data.width;
    } else if (hidden != 0 || ux + gcp->data.width > nx) {
      if (~gcp->flags & GRID_FLAG_PADDING) {
        tty_attributes(tty, &last, defaults, palette,
            s->hyperlinks);
        for (j = 0; j < OVERLAY_MAX_RANGES; j++) {
          if (r.nx[j] == 0)
            continue;
          /* Effective width drawn so far. */
          eux = r.px[j] - atx;
          if (eux < nx) {
            tty_cursor(tty, r.px[j], aty);
            nxx = nx - eux;
            if (r.nx[j] > nxx)
              r.nx[j] = nxx;
            tty_repeat_space(tty, r.nx[j]);
            ux = eux + r.nx[j];
          }
        }
      }
    } else if (gcp->attr & GRID_ATTR_CHARSET) {
      tty_attributes(tty, &last, defaults, palette,
          s->hyperlinks);
      tty_cursor(tty, atx + ux, aty);
      for (j = 0; j < gcp->data.size; j++)
        tty_putc(tty, gcp->data.data[j]);
      ux += gcp->data.width;
    } else if (~gcp->flags & GRID_FLAG_PADDING) {
      memcpy(buf + len, gcp->data.data, gcp->data.size);
      len += gcp->data.size;
      width += gcp->data.width;
    }
  }
  if (len != 0 && ((~last.flags & GRID_FLAG_CLEARED) || last.bg != 8)) {
    tty_attributes(tty, &last, defaults, palette, s->hyperlinks);
    if (last.flags & GRID_FLAG_CLEARED) {
      log_debug("%s: %zu cleared (end)", __func__, len);
      tty_clear_line(tty, defaults, aty, atx + ux, width,
          last.bg);
    } else {
      if (!wrapped || atx != 0 || ux != 0)
        tty_cursor(tty, atx + ux, aty);
      tty_putn(tty, buf, len, width);
    }
    ux += width;
  }

  if (!cleared && ux < nx) {
    log_debug("%s: %u to end of line (%zu cleared)", __func__,
        nx - ux, len);
    tty_default_attributes(tty, defaults, palette, 8,
        s->hyperlinks);
    tty_clear_line(tty, defaults, aty, atx + ux, nx - ux, 8);
  }

  tty->flags = (tty->flags & ~TTY_NOCURSOR) | flags;
  tty_update_mode(tty, tty->mode, s);
}

#ifdef ENABLE_SIXEL
/* Update context for client. */
static int
tty_set_client_cb(struct tty_ctx *ttyctx, struct client *c)
{
  struct window_pane  *wp = ttyctx->arg;

  if (c->session->curw->window != wp->window)
    return (0);
  if (wp->layout_cell == NULL)
    return (0);

  /* Set the properties relevant to the current client. */
  ttyctx->bigger = tty_window_offset(&c->tty, &ttyctx->wox, &ttyctx->woy,
      &ttyctx->wsx, &ttyctx->wsy);

  ttyctx->yoff = ttyctx->ryoff = wp->yoff;
  if (status_at_line(c) == 0)
    ttyctx->yoff += status_line_size(c);

  return (1);
}

void
tty_draw_images(struct client *c, struct window_pane *wp, struct screen *s)
{
  struct image  *im;
  struct tty_ctx   ttyctx;

  TAILQ_FOREACH(im, &s->images, entry) {
    memset(&ttyctx, 0, sizeof ttyctx);

    /* Set the client independent properties. */
    ttyctx.ocx = im->px;
    ttyctx.ocy = im->py;

    ttyctx.orlower = s->rlower;
    ttyctx.orupper = s->rupper;

    ttyctx.xoff = ttyctx.rxoff = wp->xoff;
    ttyctx.sx = wp->sx;
    ttyctx.sy = wp->sy;

    ttyctx.ptr = im;
    ttyctx.arg = wp;
    ttyctx.set_client_cb = tty_set_client_cb;
    ttyctx.allow_invisible_panes = 1;
    tty_write_one(tty_cmd_sixelimage, c, &ttyctx);
  }
}
#endif

void
tty_sync_start(struct tty *tty)
{
  if (tty->flags & TTY_BLOCK)
    return;
  if (tty->flags & TTY_SYNCING)
    return;
  tty->flags |= TTY_SYNCING;

  if (tty_term_has(tty->term, TTYC_SYNC)) {
    log_debug("%s sync start", tty->client->name);
    tty_putcode_i(tty, TTYC_SYNC, 1);
  }
}

void
tty_sync_end(struct tty *tty)
{
  if (tty->flags & TTY_BLOCK)
    return;
  if (~tty->flags & TTY_SYNCING)
    return;
  tty->flags &= ~TTY_SYNCING;

  if (tty_term_has(tty->term, TTYC_SYNC)) {
    log_debug("%s sync end", tty->client->name);
    tty_putcode_i(tty, TTYC_SYNC, 2);
  }
}

static int
tty_client_ready(const struct tty_ctx *ctx, struct client *c)
{
  if (c->session == NULL || c->tty.term == NULL)
    return (0);
  if (c->flags & CLIENT_SUSPENDED)
    return (0);

  /*
   * If invisible panes are allowed (used for passthrough), don't care if
   * redrawing or frozen.
   */
  if (ctx->allow_invisible_panes)
    return (1);

  if (c->flags & CLIENT_REDRAWWINDOW)
    return (0);
  if (c->tty.flags & TTY_FREEZE)
    return (0);
  return (1);
}

void
tty_write(void (*cmdfn)(struct tty *, const struct tty_ctx *),
    struct tty_ctx *ctx)
{
  struct client *c;
  int    state;

  if (ctx->set_client_cb == NULL)
    return;
  TAILQ_FOREACH(c, &clients, entry) {
    if (tty_client_ready(ctx, c)) {
      state = ctx->set_client_cb(ctx, c);
      if (state == -1)
        break;
      if (state == 0)
        continue;
      cmdfn(&c->tty, ctx);
    }
  }
}

#ifdef ENABLE_SIXEL
/* Only write to the incoming tty instead of every client. */
static void
tty_write_one(void (*cmdfn)(struct tty *, const struct tty_ctx *),
    struct client *c, struct tty_ctx *ctx)
{
  if (ctx->set_client_cb == NULL)
    return;
  if ((ctx->set_client_cb(ctx, c)) == 1)
    cmdfn(&c->tty, ctx);
}
#endif

void
tty_cmd_insertcharacter(struct tty *tty, const struct tty_ctx *ctx)
{
  struct client *c = tty->client;

  if (ctx->bigger ||
      !tty_full_width(tty, ctx) ||
      tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
      (!tty_term_has(tty->term, TTYC_ICH) &&
      !tty_term_has(tty->term, TTYC_ICH1)) ||
      c->overlay_check != NULL) {
    tty_draw_pane(tty, ctx, ctx->ocy);
    return;
  }

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

  tty_emulate_repeat(tty, TTYC_ICH, TTYC_ICH1, ctx->num);
}

void
tty_cmd_deletecharacter(struct tty *tty, const struct tty_ctx *ctx)
{
  struct client *c = tty->client;

  if (ctx->bigger ||
      !tty_full_width(tty, ctx) ||
      tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
      (!tty_term_has(tty->term, TTYC_DCH) &&
      !tty_term_has(tty->term, TTYC_DCH1)) ||
      c->overlay_check != NULL) {
    tty_draw_pane(tty, ctx, ctx->ocy);
    return;
  }

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

  tty_emulate_repeat(tty, TTYC_DCH, TTYC_DCH1, ctx->num);
}

void
tty_cmd_clearcharacter(struct tty *tty, const struct tty_ctx *ctx)
{
  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_clear_pane_line(tty, ctx, ctx->ocy, ctx->ocx, ctx->num, ctx->bg);
}

void
tty_cmd_insertline(struct tty *tty, const struct tty_ctx *ctx)
{
  struct client *c = tty->client;

  if (ctx->bigger ||
      !tty_full_width(tty, ctx) ||
      tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
      !tty_term_has(tty->term, TTYC_CSR) ||
      !tty_term_has(tty->term, TTYC_IL1) ||
      ctx->sx == 1 ||
      ctx->sy == 1 ||
      c->overlay_check != NULL) {
    tty_redraw_region(tty, ctx);
    return;
  }

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
  tty_margin_off(tty);
  tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

  tty_emulate_repeat(tty, TTYC_IL, TTYC_IL1, ctx->num);
  tty->cx = tty->cy = UINT_MAX;
}

void
tty_cmd_deleteline(struct tty *tty, const struct tty_ctx *ctx)
{
  struct client *c = tty->client;

  if (ctx->bigger ||
      !tty_full_width(tty, ctx) ||
      tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
      !tty_term_has(tty->term, TTYC_CSR) ||
      !tty_term_has(tty->term, TTYC_DL1) ||
      ctx->sx == 1 ||
      ctx->sy == 1 ||
      c->overlay_check != NULL) {
    tty_redraw_region(tty, ctx);
    return;
  }

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
  tty_margin_off(tty);
  tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

  tty_emulate_repeat(tty, TTYC_DL, TTYC_DL1, ctx->num);
  tty->cx = tty->cy = UINT_MAX;
}

void
tty_cmd_clearline(struct tty *tty, const struct tty_ctx *ctx)
{
  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_clear_pane_line(tty, ctx, ctx->ocy, 0, ctx->sx, ctx->bg);
}

void
tty_cmd_clearendofline(struct tty *tty, const struct tty_ctx *ctx)
{
  u_int nx = ctx->sx - ctx->ocx;

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_clear_pane_line(tty, ctx, ctx->ocy, ctx->ocx, nx, ctx->bg);
}

void
tty_cmd_clearstartofline(struct tty *tty, const struct tty_ctx *ctx)
{
  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_clear_pane_line(tty, ctx, ctx->ocy, 0, ctx->ocx + 1, ctx->bg);
}

void
tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
{
  struct client *c = tty->client;

  if (ctx->ocy != ctx->orupper)
    return;

  if (ctx->bigger ||
      (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
      tty_fake_bce(tty, &ctx->defaults, 8) ||
      !tty_term_has(tty->term, TTYC_CSR) ||
      (!tty_term_has(tty->term, TTYC_RI) &&
      !tty_term_has(tty->term, TTYC_RIN)) ||
      ctx->sx == 1 ||
      ctx->sy == 1 ||
      c->overlay_check != NULL) {
    tty_redraw_region(tty, ctx);
    return;
  }

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
  tty_margin_pane(tty, ctx);
  tty_cursor_pane(tty, ctx, ctx->ocx, ctx->orupper);

  if (tty_term_has(tty->term, TTYC_RI))
    tty_putcode(tty, TTYC_RI);
  else
    tty_putcode_i(tty, TTYC_RIN, 1);
}

void
tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
{
  struct client *c = tty->client;

  if (ctx->ocy != ctx->orlower)
    return;

  if (ctx->bigger ||
      (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
      tty_fake_bce(tty, &ctx->defaults, 8) ||
      !tty_term_has(tty->term, TTYC_CSR) ||
      ctx->sx == 1 ||
      ctx->sy == 1 ||
      c->overlay_check != NULL) {
    tty_redraw_region(tty, ctx);
    return;
  }

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
  tty_margin_pane(tty, ctx);

  /*
   * If we want to wrap a pane while using margins, the cursor needs to
   * be exactly on the right of the region. If the cursor is entirely off
   * the edge - move it back to the right. Some terminals are funny about
   * this and insert extra spaces, so only use the right if margins are
   * enabled.
   */
  if (ctx->xoff + ctx->ocx > tty->rright) {
    if (!tty_use_margin(tty))
      tty_cursor(tty, 0, ctx->yoff + ctx->ocy);
    else
      tty_cursor(tty, tty->rright, ctx->yoff + ctx->ocy);
  } else
    tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

  tty_putc(tty, '\n');
}

void
tty_cmd_scrollup(struct tty *tty, const struct tty_ctx *ctx)
{
  struct client *c = tty->client;
  u_int    i;

  if (ctx->bigger ||
      (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
      tty_fake_bce(tty, &ctx->defaults, 8) ||
      !tty_term_has(tty->term, TTYC_CSR) ||
      ctx->sx == 1 ||
      ctx->sy == 1 ||
      c->overlay_check != NULL) {
    tty_redraw_region(tty, ctx);
    return;
  }

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
  tty_margin_pane(tty, ctx);

  if (ctx->num == 1 || !tty_term_has(tty->term, TTYC_INDN)) {
    if (!tty_use_margin(tty))
      tty_cursor(tty, 0, tty->rlower);
    else
      tty_cursor(tty, tty->rright, tty->rlower);
    for (i = 0; i < ctx->num; i++)
      tty_putc(tty, '\n');
  } else {
    if (tty->cy == UINT_MAX)
      tty_cursor(tty, 0, 0);
    else
      tty_cursor(tty, 0, tty->cy);
    tty_putcode_i(tty, TTYC_INDN, ctx->num);
  }
}

void
tty_cmd_scrolldown(struct tty *tty, const struct tty_ctx *ctx)
{
  u_int    i;
  struct client *c = tty->client;

  if (ctx->bigger ||
      (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
      tty_fake_bce(tty, &ctx->defaults, 8) ||
      !tty_term_has(tty->term, TTYC_CSR) ||
      (!tty_term_has(tty->term, TTYC_RI) &&
      !tty_term_has(tty->term, TTYC_RIN)) ||
      ctx->sx == 1 ||
      ctx->sy == 1 ||
      c->overlay_check != NULL) {
    tty_redraw_region(tty, ctx);
    return;
  }

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
  tty_margin_pane(tty, ctx);
  tty_cursor_pane(tty, ctx, ctx->ocx, ctx->orupper);

  if (tty_term_has(tty->term, TTYC_RIN))
    tty_putcode_i(tty, TTYC_RIN, ctx->num);
  else {
    for (i = 0; i < ctx->num; i++)
      tty_putcode(tty, TTYC_RI);
  }
}

void
tty_cmd_clearendofscreen(struct tty *tty, const struct tty_ctx *ctx)
{
  u_int px, py, nx, ny;

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, 0, ctx->sy - 1);
  tty_margin_off(tty);

  px = 0;
  nx = ctx->sx;
  py = ctx->ocy + 1;
  ny = ctx->sy - ctx->ocy - 1;

  tty_clear_pane_area(tty, ctx, py, ny, px, nx, ctx->bg);

  px = ctx->ocx;
  nx = ctx->sx - ctx->ocx;
  py = ctx->ocy;

  tty_clear_pane_line(tty, ctx, py, px, nx, ctx->bg);
}

void
tty_cmd_clearstartofscreen(struct tty *tty, const struct tty_ctx *ctx)
{
  u_int px, py, nx, ny;

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, 0, ctx->sy - 1);
  tty_margin_off(tty);

  px = 0;
  nx = ctx->sx;
  py = 0;
  ny = ctx->ocy;

  tty_clear_pane_area(tty, ctx, py, ny, px, nx, ctx->bg);

  px = 0;
  nx = ctx->ocx + 1;
  py = ctx->ocy;

  tty_clear_pane_line(tty, ctx, py, px, nx, ctx->bg);
}

void
tty_cmd_clearscreen(struct tty *tty, const struct tty_ctx *ctx)
{
  u_int px, py, nx, ny;

  tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, 0, ctx->sy - 1);
  tty_margin_off(tty);

  px = 0;
  nx = ctx->sx;
  py = 0;
  ny = ctx->sy;

  tty_clear_pane_area(tty, ctx, py, ny, px, nx, ctx->bg);
}

void
tty_cmd_alignmenttest(struct tty *tty, const struct tty_ctx *ctx)
{
  u_int i, j;

  if (ctx->bigger) {
    ctx->redraw_cb(ctx);
    return;
  }

  tty_attributes(tty, &grid_default_cell, &ctx->defaults, ctx->palette,
      ctx->s->hyperlinks);

  tty_region_pane(tty, ctx, 0, ctx->sy - 1);
  tty_margin_off(tty);

  for (j = 0; j < ctx->sy; j++) {
    tty_cursor_pane(tty, ctx, 0, j);
    for (i = 0; i < ctx->sx; i++)
      tty_putc(tty, 'E');
  }
}

void
tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
{
  const struct grid_cell  *gcp = ctx->cell;
  struct screen   *s = ctx->s;
  struct overlay_ranges  r;
  u_int      px, py, i, vis = 0;

  px = ctx->xoff + ctx->ocx - ctx->wox;
  py = ctx->yoff + ctx->ocy - ctx->woy;
  if (!tty_is_visible(tty, ctx, ctx->ocx, ctx->ocy, 1, 1) ||
      (gcp->data.width == 1 && !tty_check_overlay(tty, px, py)))
    return;

  /* Handle partially obstructed wide characters. */
  if (gcp->data.width > 1) {
    tty_check_overlay_range(tty, px, py, gcp->data.width, &r);
    for (i = 0; i < OVERLAY_MAX_RANGES; i++)
      vis += r.nx[i];
    if (vis < gcp->data.width) {
      tty_draw_line(tty, s, s->cx, s->cy, gcp->data.width,
          px, py, &ctx->defaults, ctx->palette);
      return;
    }
  }

  if (ctx->xoff + ctx->ocx - ctx->wox > tty->sx - 1 &&
      ctx->ocy == ctx->orlower &&
      tty_full_width(tty, ctx))
    tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);

  tty_margin_off(tty);
  tty_cursor_pane_unless_wrap(tty, ctx, ctx->ocx, ctx->ocy);

  tty_cell(tty, ctx->cell, &ctx->defaults, ctx->palette,
      ctx->s->hyperlinks);

  if (ctx->num == 1)
    tty_invalidate(tty);
}

void
tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
{
  struct overlay_ranges  r;
  u_int      i, px, py, cx;
  char      *cp = ctx->ptr;

  if (!tty_is_visible(tty, ctx, ctx->ocx, ctx->ocy, ctx->num, 1))
    return;

  if (ctx->bigger &&
      (ctx->xoff + ctx->ocx < ctx->wox ||
      ctx->xoff + ctx->ocx + ctx->num > ctx->wox + ctx->wsx)) {
    if (!ctx->wrapped ||
        !tty_full_width(tty, ctx) ||
        (tty->term->flags & TERM_NOAM) ||
        ctx->xoff + ctx->ocx != 0 ||
        ctx->yoff + ctx->ocy != tty->cy + 1 ||
        tty->cx < tty->sx ||
        tty->cy == tty->rlower)
      tty_draw_pane(tty, ctx, ctx->ocy);
    else
      ctx->redraw_cb(ctx);
    return;
  }

  tty_margin_off(tty);
  tty_cursor_pane_unless_wrap(tty, ctx, ctx->ocx, ctx->ocy);
  tty_attributes(tty, ctx->cell, &ctx->defaults, ctx->palette, ctx->s->hyperlinks);

  /* Get tty position from pane position for overlay check. */
  px = ctx->xoff + ctx->ocx - ctx->wox;
  py = ctx->yoff + ctx->ocy - ctx->woy;

  tty_check_overlay_range(tty, px, py, ctx->num, &r);
  for (i = 0; i < OVERLAY_MAX_RANGES; i++) {
    if (r.nx[i] == 0)
      continue;
    /* Convert back to pane position for printing. */
    cx = r.px[i] - ctx->xoff + ctx->wox;
    tty_cursor_pane_unless_wrap(tty, ctx, cx, ctx->ocy);
    tty_putn(tty, cp + r.px[i] - px, r.nx[i], r.nx[i]);
  }
}

void
tty_cmd_setselection(struct tty *tty, const struct tty_ctx *ctx)
{
  tty_set_selection(tty, ctx->ptr2, ctx->ptr, ctx->num);
}

void
tty_set_selection(struct tty *tty, const char *flags, const char *buf,
    size_t len)
{
  char  *encoded;
  size_t   size;

  if (~tty->flags & TTY_STARTED)
    return;
  if (!tty_term_has(tty->term, TTYC_MS))
    return;

  size = 4 * ((len + 2) / 3) + 1; /* storage for base64 */
  encoded = xmalloc(size);

  b64_ntop(buf, len, encoded, size);
  tty->flags |= TTY_NOBLOCK;
  tty_putcode_ss(tty, TTYC_MS, flags, encoded);

  free(encoded);
}

void
tty_cmd_rawstring(struct tty *tty, const struct tty_ctx *ctx)
{
  tty->flags |= TTY_NOBLOCK;
  tty_add(tty, ctx->ptr, ctx->num);
  tty_invalidate(tty);
}

#ifdef ENABLE_SIXEL
void
tty_cmd_sixelimage(struct tty *tty, const struct tty_ctx *ctx)
{
  struct image    *im = ctx->ptr;
  struct sixel_image  *si = im->data;
  struct sixel_image  *new;
  char      *data;
  size_t       size;
  u_int      cx = ctx->ocx, cy = ctx->ocy, sx, sy;
  u_int      i, j, x, y, rx, ry;
  int      fallback = 0;

  if ((~tty->term->flags & TERM_SIXEL) &&
            !tty_term_has(tty->term, TTYC_SXL))
    fallback = 1;
  if (tty->xpixel == 0 || tty->ypixel == 0)
    fallback = 1;

  sixel_size_in_cells(si, &sx, &sy);
  log_debug("%s: image is %ux%u", __func__, sx, sy);
  if (!tty_clamp_area(tty, ctx, cx, cy, sx, sy, &i, &j, &x, &y, &rx, &ry))
    return;
  log_debug("%s: clamping to %u,%u-%u,%u", __func__, i, j, rx, ry);

  if (fallback == 1) {
    data = xstrdup(im->fallback);
    size = strlen(data);
  } else {
    new = sixel_scale(si, tty->xpixel, tty->ypixel, i, j, rx, ry, 0);
    if (new == NULL)
      return;

    data = sixel_print(new, si, &size);
  }
  if (data != NULL) {
    log_debug("%s: %zu bytes: %s", __func__, size, data);
    tty_region_off(tty);
    tty_margin_off(tty);
    tty_cursor(tty, x, y);

    tty->flags |= TTY_NOBLOCK;
    tty_add(tty, data, size);
    tty_invalidate(tty);
    free(data);
  }

  if (fallback == 0)
    sixel_free(new);
}
#endif

void
tty_cmd_syncstart(struct tty *tty, const struct tty_ctx *ctx)
{
  if (ctx->num == 0x11) {
    /*
     * This is an overlay and a command that moves the cursor so
     * start synchronized updates.
     */
    tty_sync_start(tty);
  } else if (~ctx->num & 0x10) {
    /*
     * This is a pane. If there is an overlay, always start;
     * otherwise, only if requested.
     */
    if (ctx->num || tty->client->overlay_draw != NULL)
      tty_sync_start(tty);
  }
}

void
tty_cell(struct tty *tty, const struct grid_cell *gc,
    const struct grid_cell *defaults, struct colour_palette *palette,
    struct hyperlinks *hl)
{
  const struct grid_cell  *gcp;

  /* Skip last character if terminal is stupid. */
  if ((tty->term->flags & TERM_NOAM) &&
      tty->cy == tty->sy - 1 &&
      tty->cx == tty->sx - 1)
    return;

  /* If this is a padding character, do nothing. */
  if (gc->flags & GRID_FLAG_PADDING)
    return;

  /* Check the output codeset and apply attributes. */
  gcp = tty_check_codeset(tty, gc);
  tty_attributes(tty, gcp, defaults, palette, hl);

  /* If it is a single character, write with putc to handle ACS. */
  if (gcp->data.size == 1) {
    tty_attributes(tty, gcp, defaults, palette, hl);
    if (*gcp->data.data < 0x20 || *gcp->data.data == 0x7f)
      return;
    tty_putc(tty, *gcp->data.data);
    return;
  }

  /* Write the data. */
  tty_putn(tty, gcp->data.data, gcp->data.size, gcp->data.width);
}

void
tty_reset(struct tty *tty)
{
  struct grid_cell  *gc = &tty->cell;

  if (!grid_cells_equal(gc, &grid_default_cell)) {
    if (gc->link != 0)
      tty_putcode_ss(tty, TTYC_HLS, "", "");
    if ((gc->attr & GRID_ATTR_CHARSET) && tty_acs_needed(tty))
      tty_putcode(tty, TTYC_RMACS);
    tty_putcode(tty, TTYC_SGR0);
    memcpy(gc, &grid_default_cell, sizeof *gc);
  }
  memcpy(&tty->last_cell, &grid_default_cell, sizeof tty->last_cell);
}

static void
tty_invalidate(struct tty *tty)
{
  memcpy(&tty->cell, &grid_default_cell, sizeof tty->cell);
  memcpy(&tty->last_cell, &grid_default_cell, sizeof tty->last_cell);

  tty->cx = tty->cy = UINT_MAX;
  tty->rupper = tty->rleft = UINT_MAX;
  tty->rlower = tty->rright = UINT_MAX;

  if (tty->flags & TTY_STARTED) {
    if (tty_use_margin(tty))
      tty_putcode(tty, TTYC_ENMG);
    tty_putcode(tty, TTYC_SGR0);

    tty->mode = ALL_MODES;
    tty_update_mode(tty, MODE_CURSOR, NULL);

    tty_cursor(tty, 0, 0);
    tty_region_off(tty);
    tty_margin_off(tty);
  } else
    tty->mode = MODE_CURSOR;
}

/* Turn off margin. */
void
tty_region_off(struct tty *tty)
{
  tty_region(tty, 0, tty->sy - 1);
}

/* Set region inside pane. */
static void
tty_region_pane(struct tty *tty, const struct tty_ctx *ctx, u_int rupper,
    u_int rlower)
{
  tty_region(tty, ctx->yoff + rupper - ctx->woy,
      ctx->yoff + rlower - ctx->woy);
}

/* Set region at absolute position. */
static void
tty_region(struct tty *tty, u_int rupper, u_int rlower)
{
  if (tty->rlower == rlower && tty->rupper == rupper)
    return;
  if (!tty_term_has(tty->term, TTYC_CSR))
    return;

  tty->rupper = rupper;
  tty->rlower = rlower;

  /*
   * Some terminals (such as PuTTY) do not correctly reset the cursor to
   * 0,0 if it is beyond the last column (they do not reset their wrap
   * flag so further output causes a line feed). As a workaround, do an
   * explicit move to 0 first.
   */
  if (tty->cx >= tty->sx) {
    if (tty->cy == UINT_MAX)
      tty_cursor(tty, 0, 0);
    else
      tty_cursor(tty, 0, tty->cy);
  }

  tty_putcode_ii(tty, TTYC_CSR, tty->rupper, tty->rlower);
  tty->cx = tty->cy = UINT_MAX;
}

/* Turn off margin. */
void
tty_margin_off(struct tty *tty)
{
  tty_margin(tty, 0, tty->sx - 1);
}

/* Set margin inside pane. */
static void
tty_margin_pane(struct tty *tty, const struct tty_ctx *ctx)
{
  tty_margin(tty, ctx->xoff - ctx->wox,
      ctx->xoff + ctx->sx - 1 - ctx->wox);
}

/* Set margin at absolute position. */
static void
tty_margin(struct tty *tty, u_int rleft, u_int rright)
{
  if (!tty_use_margin(tty))
    return;
  if (tty->rleft == rleft && tty->rright == rright)
    return;

  tty_putcode_ii(tty, TTYC_CSR, tty->rupper, tty->rlower);

  tty->rleft = rleft;
  tty->rright = rright;

  if (rleft == 0 && rright == tty->sx - 1)
    tty_putcode(tty, TTYC_CLMG);
  else
    tty_putcode_ii(tty, TTYC_CMG, rleft, rright);
  tty->cx = tty->cy = UINT_MAX;
}

/*
 * Move the cursor, unless it would wrap itself when the next character is
 * printed.
 */
static void
tty_cursor_pane_unless_wrap(struct tty *tty, const struct tty_ctx *ctx,
    u_int cx, u_int cy)
{
  if (!ctx->wrapped ||
      !tty_full_width(tty, ctx) ||
      (tty->term->flags & TERM_NOAM) ||
      ctx->xoff + cx != 0 ||
      ctx->yoff + cy != tty->cy + 1 ||
      tty->cx < tty->sx ||
      tty->cy == tty->rlower)
    tty_cursor_pane(tty, ctx, cx, cy);
  else
    log_debug("%s: will wrap at %u,%u", __func__, tty->cx, tty->cy);
}

/* Move cursor inside pane. */
static void
tty_cursor_pane(struct tty *tty, const struct tty_ctx *ctx, u_int cx, u_int cy)
{
  tty_cursor(tty, ctx->xoff + cx - ctx->wox, ctx->yoff + cy - ctx->woy);
}

/* Move cursor to absolute position. */
void
tty_cursor(struct tty *tty, u_int cx, u_int cy)
{
  struct tty_term *term = tty->term;
  u_int    thisx, thisy;
  int    change;

  if (tty->flags & TTY_BLOCK)
    return;

  thisx = tty->cx;
  thisy = tty->cy;

  /*
   * If in the automargin space, and want to be there, do not move.
   * Otherwise, force the cursor to be in range (and complain).
   */
  if (cx == thisx && cy == thisy && cx == tty->sx)
    return;
  if (cx > tty->sx - 1) {
    log_debug("%s: x too big %u > %u", __func__, cx, tty->sx - 1);
    cx = tty->sx - 1;
  }

  /* No change. */
  if (cx == thisx && cy == thisy)
    return;

  /* Currently at the very end of the line - use absolute movement. */
  if (thisx > tty->sx - 1)
    goto absolute;

  /* Move to home position (0, 0). */
  if (cx == 0 && cy == 0 && tty_term_has(term, TTYC_HOME)) {
    tty_putcode(tty, TTYC_HOME);
    goto out;
  }

  /* Zero on the next line. */
  if (cx == 0 && cy == thisy + 1 && thisy != tty->rlower &&
      (!tty_use_margin(tty) || tty->rleft == 0)) {
    tty_putc(tty, '\r');
    tty_putc(tty, '\n');
    goto out;
  }

  /* Moving column or row. */
  if (cy == thisy) {
    /*
     * Moving column only, row staying the same.
     */

    /* To left edge. */
    if (cx == 0 && (!tty_use_margin(tty) || tty->rleft == 0)) {
      tty_putc(tty, '\r');
      goto out;
    }

    /* One to the left. */
    if (cx == thisx - 1 && tty_term_has(term, TTYC_CUB1)) {
      tty_putcode(tty, TTYC_CUB1);
      goto out;
    }

    /* One to the right. */
    if (cx == thisx + 1 && tty_term_has(term, TTYC_CUF1)) {
      tty_putcode(tty, TTYC_CUF1);
      goto out;
    }

    /* Calculate difference. */
    change = thisx - cx;  /* +ve left, -ve right */

    /*
     * Use HPA if change is larger than absolute, otherwise move
     * the cursor with CUB/CUF.
     */
    if ((u_int) abs(change) > cx && tty_term_has(term, TTYC_HPA)) {
      tty_putcode_i(tty, TTYC_HPA, cx);
      goto out;
    } else if (change > 0 &&
        tty_term_has(term, TTYC_CUB) &&
        !tty_use_margin(tty)) {
      if (change == 2 && tty_term_has(term, TTYC_CUB1)) {
        tty_putcode(tty, TTYC_CUB1);
        tty_putcode(tty, TTYC_CUB1);
        goto out;
      }
      tty_putcode_i(tty, TTYC_CUB, change);
      goto out;
    } else if (change < 0 &&
        tty_term_has(term, TTYC_CUF) &&
        !tty_use_margin(tty)) {
      tty_putcode_i(tty, TTYC_CUF, -change);
      goto out;
    }
  } else if (cx == thisx) {
    /*
     * Moving row only, column staying the same.
     */

    /* One above. */
    if (thisy != tty->rupper &&
        cy == thisy - 1 && tty_term_has(term, TTYC_CUU1)) {
      tty_putcode(tty, TTYC_CUU1);
      goto out;
    }

    /* One below. */
    if (thisy != tty->rlower &&
        cy == thisy + 1 && tty_term_has(term, TTYC_CUD1)) {
      tty_putcode(tty, TTYC_CUD1);
      goto out;
    }

    /* Calculate difference. */
    change = thisy - cy;  /* +ve up, -ve down */

    /*
     * Try to use VPA if change is larger than absolute or if this
     * change would cross the scroll region, otherwise use CUU/CUD.
     */
    if ((u_int) abs(change) > cy ||
        (change < 0 && cy - change > tty->rlower) ||
        (change > 0 && cy - change < tty->rupper)) {
          if (tty_term_has(term, TTYC_VPA)) {
            tty_putcode_i(tty, TTYC_VPA, cy);
            goto out;
          }
    } else if (change > 0 && tty_term_has(term, TTYC_CUU)) {
      tty_putcode_i(tty, TTYC_CUU, change);
      goto out;
    } else if (change < 0 && tty_term_has(term, TTYC_CUD)) {
      tty_putcode_i(tty, TTYC_CUD, -change);
      goto out;
    }
  }

absolute:
  /* Absolute movement. */
  tty_putcode_ii(tty, TTYC_CUP, cy, cx);

out:
  tty->cx = cx;
  tty->cy = cy;
}

static void
tty_hyperlink(struct tty *tty, const struct grid_cell *gc,
    struct hyperlinks *hl)
{
  const char  *uri, *id;

  if (gc->link == tty->cell.link)
    return;
  tty->cell.link = gc->link;

  if (hl == NULL)
    return;

  if (gc->link == 0 || !hyperlinks_get(hl, gc->link, &uri, NULL, &id))
    tty_putcode_ss(tty, TTYC_HLS, "", "");
  else
    tty_putcode_ss(tty, TTYC_HLS, id, uri);
}

void
tty_attributes(struct tty *tty, const struct grid_cell *gc,
    const struct grid_cell *defaults, struct colour_palette *palette,
    struct hyperlinks *hl)
{
  struct grid_cell  *tc = &tty->cell, gc2;
  int      changed;

  /* Copy cell and update default colours. */
  memcpy(&gc2, gc, sizeof gc2);
  if (~gc->flags & GRID_FLAG_NOPALETTE) {
    if (gc2.fg == 8)
      gc2.fg = defaults->fg;
    if (gc2.bg == 8)
      gc2.bg = defaults->bg;
  }

  /* Ignore cell if it is the same as the last one. */
  if (gc2.attr == tty->last_cell.attr &&
      gc2.fg == tty->last_cell.fg &&
      gc2.bg == tty->last_cell.bg &&
      gc2.us == tty->last_cell.us &&
    gc2.link == tty->last_cell.link)
    return;

  /*
   * If no setab, try to use the reverse attribute as a best-effort for a
   * non-default background. This is a bit of a hack but it doesn't do
   * any serious harm and makes a couple of applications happier.
   */
  if (!tty_term_has(tty->term, TTYC_SETAB)) {
    if (gc2.attr & GRID_ATTR_REVERSE) {
      if (gc2.fg != 7 && !COLOUR_DEFAULT(gc2.fg))
        gc2.attr &= ~GRID_ATTR_REVERSE;
    } else {
      if (gc2.bg != 0 && !COLOUR_DEFAULT(gc2.bg))
        gc2.attr |= GRID_ATTR_REVERSE;
    }
  }

  /* Fix up the colours if necessary. */
  tty_check_fg(tty, palette, &gc2);
  tty_check_bg(tty, palette, &gc2);
  tty_check_us(tty, palette, &gc2);

  /*
   * If any bits are being cleared or the underline colour is now default,
   * reset everything.
   */
  if ((tc->attr & ~gc2.attr) || (tc->us != gc2.us && gc2.us == 0))
    tty_reset(tty);

  /*
   * Set the colours. This may call tty_reset() (so it comes next) and
   * may add to (NOT remove) the desired attributes.
   */
  tty_colours(tty, &gc2);

  /* Filter out attribute bits already set. */
  changed = gc2.attr & ~tc->attr;
  tc->attr = gc2.attr;

  /* Set the attributes. */
  if (changed & GRID_ATTR_BRIGHT)
    tty_putcode(tty, TTYC_BOLD);
  if (changed & GRID_ATTR_DIM)
    tty_putcode(tty, TTYC_DIM);
  if (changed & GRID_ATTR_ITALICS)
    tty_set_italics(tty);
  if (changed & GRID_ATTR_ALL_UNDERSCORE) {
    if ((changed & GRID_ATTR_UNDERSCORE) ||
        !tty_term_has(tty->term, TTYC_SMULX))
      tty_putcode(tty, TTYC_SMUL);
    else if (changed & GRID_ATTR_UNDERSCORE_2)
      tty_putcode_i(tty, TTYC_SMULX, 2);
    else if (changed & GRID_ATTR_UNDERSCORE_3)
      tty_putcode_i(tty, TTYC_SMULX, 3);
    else if (changed & GRID_ATTR_UNDERSCORE_4)
      tty_putcode_i(tty, TTYC_SMULX, 4);
    else if (changed & GRID_ATTR_UNDERSCORE_5)
      tty_putcode_i(tty, TTYC_SMULX, 5);
  }
  if (changed & GRID_ATTR_BLINK)
    tty_putcode(tty, TTYC_BLINK);
  if (changed & GRID_ATTR_REVERSE) {
    if (tty_term_has(tty->term, TTYC_REV))
      tty_putcode(tty, TTYC_REV);
    else if (tty_term_has(tty->term, TTYC_SMSO))
      tty_putcode(tty, TTYC_SMSO);
  }
  if (changed & GRID_ATTR_HIDDEN)
    tty_putcode(tty, TTYC_INVIS);
  if (changed & GRID_ATTR_STRIKETHROUGH)
    tty_putcode(tty, TTYC_SMXX);
  if (changed & GRID_ATTR_OVERLINE)
    tty_putcode(tty, TTYC_SMOL);
  if ((changed & GRID_ATTR_CHARSET) && tty_acs_needed(tty))
    tty_putcode(tty, TTYC_SMACS);

  /* Set hyperlink if any. */
  tty_hyperlink(tty, gc, hl);

  memcpy(&tty->last_cell, &gc2, sizeof tty->last_cell);
}

static void
tty_colours(struct tty *tty, const struct grid_cell *gc)
{
  struct grid_cell  *tc = &tty->cell;

  /* No changes? Nothing is necessary. */
  if (gc->fg == tc->fg && gc->bg == tc->bg && gc->us == tc->us)
    return;

  /*
   * Is either the default colour? This is handled specially because the
   * best solution might be to reset both colours to default, in which
   * case if only one is default need to fall onward to set the other
   * colour.
   */
  if (COLOUR_DEFAULT(gc->fg) || COLOUR_DEFAULT(gc->bg)) {
    /*
     * If don't have AX, send sgr0. This resets both colours to default.
     * Otherwise, try to set the default colour only as needed.
     */
    if (!tty_term_flag(tty->term, TTYC_AX))
      tty_reset(tty);
    else {
      if (COLOUR_DEFAULT(gc->fg) && !COLOUR_DEFAULT(tc->fg)) {
        tty_puts(tty, "\033[39m");
        tc->fg = gc->fg;
      }
      if (COLOUR_DEFAULT(gc->bg) && !COLOUR_DEFAULT(tc->bg)) {
        tty_puts(tty, "\033[49m");
        tc->bg = gc->bg;
      }
    }
  }

  /* Set the foreground colour. */
  if (!COLOUR_DEFAULT(gc->fg) && gc->fg != tc->fg)
    tty_colours_fg(tty, gc);

  /*
   * Set the background colour. This must come after the foreground as
   * tty_colours_fg() can call tty_reset().
   */
  if (!COLOUR_DEFAULT(gc->bg) && gc->bg != tc->bg)
    tty_colours_bg(tty, gc);

  /* Set the underscore colour. */
  if (gc->us != tc->us)
    tty_colours_us(tty, gc);
}

static void
tty_check_fg(struct tty *tty, struct colour_palette *palette,
    struct grid_cell *gc)
{
  u_char  r, g, b;
  u_int colours;
  int c;

  /*
   * Perform substitution if this pane has a palette. If the bright
   * attribute is set and Nobr is not present, use the bright entry in
   * the palette by changing to the aixterm colour
   */
  if (~gc->flags & GRID_FLAG_NOPALETTE) {
    c = gc->fg;
    if (c < 8 &&
        gc->attr & GRID_ATTR_BRIGHT &&
        !tty_term_has(tty->term, TTYC_NOBR))
      c += 90;
    if ((c = colour_palette_get(palette, c)) != -1)
      gc->fg = c;
  }

  /* Is this a 24-bit colour? */
  if (gc->fg & COLOUR_FLAG_RGB) {
    /* Not a 24-bit terminal? Translate to 256-colour palette. */
    if (tty->term->flags & TERM_RGBCOLOURS)
      return;
    colour_split_rgb(gc->fg, &r, &g, &b);
    gc->fg = colour_find_rgb(r, g, b);
  }

  /* How many colours does this terminal have? */
  if (tty->term->flags & TERM_256COLOURS)
    colours = 256;
  else
    colours = tty_term_number(tty->term, TTYC_COLORS);

  /* Is this a 256-colour colour? */
  if (gc->fg & COLOUR_FLAG_256) {
    /* And not a 256 colour mode? */
    if (colours < 256) {
      gc->fg = colour_256to16(gc->fg);
      if (gc->fg & 8) {
        gc->fg &= 7;
        if (colours >= 16)
          gc->fg += 90;
      }
    }
    return;
  }

  /* Is this an aixterm colour? */
  if (gc->fg >= 90 && gc->fg <= 97 && colours < 16) {
    gc->fg -= 90;
    gc->attr |= GRID_ATTR_BRIGHT;
  }
}

static void
tty_check_bg(struct tty *tty, struct colour_palette *palette,
    struct grid_cell *gc)
{
  u_char  r, g, b;
  u_int colours;
  int c;

  /* Perform substitution if this pane has a palette. */
  if (~gc->flags & GRID_FLAG_NOPALETTE) {
    if ((c = colour_palette_get(palette, gc->bg)) != -1)
      gc->bg = c;
  }

  /* Is this a 24-bit colour? */
  if (gc->bg & COLOUR_FLAG_RGB) {
    /* Not a 24-bit terminal? Translate to 256-colour palette. */
    if (tty->term->flags & TERM_RGBCOLOURS)
      return;
    colour_split_rgb(gc->bg, &r, &g, &b);
    gc->bg = colour_find_rgb(r, g, b);
  }

  /* How many colours does this terminal have? */
  if (tty->term->flags & TERM_256COLOURS)
    colours = 256;
  else
    colours = tty_term_number(tty->term, TTYC_COLORS);

  /* Is this a 256-colour colour? */
  if (gc->bg & COLOUR_FLAG_256) {
    /*
     * And not a 256 colour mode? Translate to 16-colour
     * palette. Bold background doesn't exist portably, so just
     * discard the bold bit if set.
     */
    if (colours < 256) {
      gc->bg = colour_256to16(gc->bg);
      if (gc->bg & 8) {
        gc->bg &= 7;
        if (colours >= 16)
          gc->bg += 90;
      }
    }
    return;
  }

  /* Is this an aixterm colour? */
  if (gc->bg >= 90 && gc->bg <= 97 && colours < 16)
    gc->bg -= 90;
}

static void
tty_check_us(__unused struct tty *tty, struct colour_palette *palette,
    struct grid_cell *gc)
{
  int c;

  /* Perform substitution if this pane has a palette. */
  if (~gc->flags & GRID_FLAG_NOPALETTE) {
    if ((c = colour_palette_get(palette, gc->us)) != -1)
      gc->us = c;
  }

  /* Convert underscore colour if only RGB can be supported. */
  if (!tty_term_has(tty->term, TTYC_SETULC1)) {
        if ((c = colour_force_rgb (gc->us)) == -1)
          gc->us = 8;
        else
          gc->us = c;
  }
}

static void
tty_colours_fg(struct tty *tty, const struct grid_cell *gc)
{
  struct grid_cell  *tc = &tty->cell;
  char       s[32];

  /*
   * If the current colour is an aixterm bright colour and the new is not,
   * reset because some terminals do not clear bright correctly.
   */
  if (tty->cell.fg >= 90 &&
      tty->cell.bg <= 97 &&
      (gc->fg < 90 || gc->fg > 97))
    tty_reset(tty);

  /* Is this a 24-bit or 256-colour colour? */
  if (gc->fg & COLOUR_FLAG_RGB || gc->fg & COLOUR_FLAG_256) {
    if (tty_try_colour(tty, gc->fg, "38") == 0)
      goto save;
    /* Should not get here, already converted in tty_check_fg. */
    return;
  }

  /* Is this an aixterm bright colour? */
  if (gc->fg >= 90 && gc->fg <= 97) {
    if (tty->term->flags & TERM_256COLOURS) {
      xsnprintf(s, sizeof s, "\033[%dm", gc->fg);
      tty_puts(tty, s);
    } else
      tty_putcode_i(tty, TTYC_SETAF, gc->fg - 90 + 8);
    goto save;
  }

  /* Otherwise set the foreground colour. */
  tty_putcode_i(tty, TTYC_SETAF, gc->fg);

save:
  /* Save the new values in the terminal current cell. */
  tc->fg = gc->fg;
}

static void
tty_colours_bg(struct tty *tty, const struct grid_cell *gc)
{
  struct grid_cell  *tc = &tty->cell;
  char       s[32];

  /* Is this a 24-bit or 256-colour colour? */
  if (gc->bg & COLOUR_FLAG_RGB || gc->bg & COLOUR_FLAG_256) {
    if (tty_try_colour(tty, gc->bg, "48") == 0)
      goto save;
    /* Should not get here, already converted in tty_check_bg. */
    return;
  }

  /* Is this an aixterm bright colour? */
  if (gc->bg >= 90 && gc->bg <= 97) {
    if (tty->term->flags & TERM_256COLOURS) {
      xsnprintf(s, sizeof s, "\033[%dm", gc->bg + 10);
      tty_puts(tty, s);
    } else
      tty_putcode_i(tty, TTYC_SETAB, gc->bg - 90 + 8);
    goto save;
  }

  /* Otherwise set the background colour. */
  tty_putcode_i(tty, TTYC_SETAB, gc->bg);

save:
  /* Save the new values in the terminal current cell. */
  tc->bg = gc->bg;
}

static void
tty_colours_us(struct tty *tty, const struct grid_cell *gc)
{
  struct grid_cell  *tc = &tty->cell;
  u_int      c;
  u_char       r, g, b;

  /* Clear underline colour. */
  if (COLOUR_DEFAULT(gc->us)) {
    tty_putcode(tty, TTYC_OL);
    goto save;
  }

  /*
   * If this is not an RGB colour, use Setulc1 if it exists, otherwise
   * convert.
   */
  if (~gc->us & COLOUR_FLAG_RGB) {
    c = gc->us;
    if ((~c & COLOUR_FLAG_256) && (c >= 90 && c <= 97))
      c -= 82;
    tty_putcode_i(tty, TTYC_SETULC1, c & ~COLOUR_FLAG_256);
    return;
  }

  /*
   * Setulc and setal follows the ncurses(3) one argument "direct colour"
   * capability format. Calculate the colour value.
   */
  colour_split_rgb(gc->us, &r, &g, &b);
  c = (65536 * r) + (256 * g) + b;

  /*
   * Write the colour. Only use setal if the RGB flag is set because the
   * non-RGB version may be wrong.
   */
  if (tty_term_has(tty->term, TTYC_SETULC))
    tty_putcode_i(tty, TTYC_SETULC, c);
  else if (tty_term_has(tty->term, TTYC_SETAL) &&
      tty_term_has(tty->term, TTYC_RGB))
    tty_putcode_i(tty, TTYC_SETAL, c);

save:
  /* Save the new values in the terminal current cell. */
  tc->us = gc->us;
}

static int
tty_try_colour(struct tty *tty, int colour, const char *type)
{
  u_char  r, g, b;

  if (colour & COLOUR_FLAG_256) {
    if (*type == '3' && tty_term_has(tty->term, TTYC_SETAF))
      tty_putcode_i(tty, TTYC_SETAF, colour & 0xff);
    else if (tty_term_has(tty->term, TTYC_SETAB))
      tty_putcode_i(tty, TTYC_SETAB, colour & 0xff);
    return (0);
  }

  if (colour & COLOUR_FLAG_RGB) {
    colour_split_rgb(colour & 0xffffff, &r, &g, &b);
    if (*type == '3' && tty_term_has(tty->term, TTYC_SETRGBF))
      tty_putcode_iii(tty, TTYC_SETRGBF, r, g, b);
    else if (tty_term_has(tty->term, TTYC_SETRGBB))
      tty_putcode_iii(tty, TTYC_SETRGBB, r, g, b);
    return (0);
  }

  return (-1);
}

static void
tty_window_default_style(struct grid_cell *gc, struct window_pane *wp)
{
  memcpy(gc, &grid_default_cell, sizeof *gc);
  gc->fg = wp->palette.fg;
  gc->bg = wp->palette.bg;
}

void
tty_default_colours(struct grid_cell *gc, struct window_pane *wp)
{
  struct options    *oo = wp->options;
  struct format_tree  *ft;

  memcpy(gc, &grid_default_cell, sizeof *gc);

  if (wp->flags & PANE_STYLECHANGED) {
    log_debug("%%%u: style changed", wp->id);
    wp->flags &= ~PANE_STYLECHANGED;

    ft = format_create(NULL, NULL, FORMAT_PANE|wp->id,
        FORMAT_NOJOBS);
    format_defaults(ft, NULL, NULL, NULL, wp);
    tty_window_default_style(&wp->cached_active_gc, wp);
    style_add(&wp->cached_active_gc, oo, "window-active-style", ft);
    tty_window_default_style(&wp->cached_gc, wp);
    style_add(&wp->cached_gc, oo, "window-style", ft);
    format_free(ft);
  }

  if (gc->fg == 8) {
    if (wp == wp->window->active && wp->cached_active_gc.fg != 8)
      gc->fg = wp->cached_active_gc.fg;
    else
      gc->fg = wp->cached_gc.fg;
  }

  if (gc->bg == 8) {
    if (wp == wp->window->active && wp->cached_active_gc.bg != 8)
      gc->bg = wp->cached_active_gc.bg;
    else
      gc->bg = wp->cached_gc.bg;
  }
}

static void
tty_default_attributes(struct tty *tty, const struct grid_cell *defaults,
    struct colour_palette *palette, u_int bg, struct hyperlinks *hl)
{
  struct grid_cell  gc;

  memcpy(&gc, &grid_default_cell, sizeof gc);
  gc.bg = bg;
  tty_attributes(tty, &gc, defaults, palette, hl);
}

static void
tty_clipboard_query_callback(__unused int fd, __unused short events, void *data)
{
  struct tty  *tty = data;
  struct client *c = tty->client;

  c->flags &= ~CLIENT_CLIPBOARDBUFFER;
  free(c->clipboard_panes);
  c->clipboard_panes = NULL;
  c->clipboard_npanes = 0;

  tty->flags &= ~TTY_OSC52QUERY;
}

void
tty_clipboard_query(struct tty *tty)
{
  struct timeval   tv = { .tv_sec = TTY_QUERY_TIMEOUT };

  if ((~tty->flags & TTY_STARTED) || (tty->flags & TTY_OSC52QUERY))
    return;
  tty_putcode_ss(tty, TTYC_MS, "", "?");

  tty->flags |= TTY_OSC52QUERY;
  evtimer_set(&tty->clipboard_timer, tty_clipboard_query_callback, tty);
  evtimer_add(&tty->clipboard_timer, &tv);
}

Coverage Report

Created: 2024-09-08 06:17