usr.bin/tmux/window.c

root/usr.bin/tmux/window.c
/* $OpenBSD: window.c,v 1.313 2026/04/04 16:40:27 nicm Exp $ */

/*
 * 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 <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <fnmatch.h>
#include <regex.h>
#include <signal.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <util.h>
#include <vis.h>

#include "tmux.h"

/*
 * Each window is attached to a number of panes, each of which is a pty. This
 * file contains code to handle them.
 *
 * A pane has two buffers attached, these are filled and emptied by the main
 * server poll loop. Output data is received from pty's in screen format,
 * translated and returned as a series of escape sequences and strings via
 * input_parse (in input.c). Input data is received as key codes and written
 * directly via input_key.
 *
 * Each pane also has a "virtual" screen (screen.c) which contains the current
 * state and is redisplayed when the window is reattached to a client.
 *
 * Windows are stored directly on a global array and wrapped in any number of
 * winlink structs to be linked onto local session RB trees. A reference count
 * is maintained and a window removed from the global list and destroyed when
 * it reaches zero.
 */

/* Global window list. */
struct windows windows;

/* Global panes tree. */
struct window_pane_tree all_window_panes;
static u_int    next_window_pane_id;
static u_int    next_window_id;
static u_int    next_active_point;

struct window_pane_input_data {
        struct cmdq_item        *item;
        u_int                    wp;
        struct client_file      *file;
};

static struct window_pane *window_pane_create(struct window *, u_int, u_int,
                    u_int);
static void     window_pane_destroy(struct window_pane *);
static void     window_pane_full_size_offset(struct window_pane *wp,
                    u_int *xoff, u_int *yoff, u_int *sx, u_int *sy);

RB_GENERATE(windows, window, entry, window_cmp);
RB_GENERATE(winlinks, winlink, entry, winlink_cmp);
RB_GENERATE(window_pane_tree, window_pane, tree_entry, window_pane_cmp);

int
window_cmp(struct window *w1, struct window *w2)
{
        return (w1->id - w2->id);
}

int
winlink_cmp(struct winlink *wl1, struct winlink *wl2)
{
        return (wl1->idx - wl2->idx);
}

int
window_pane_cmp(struct window_pane *wp1, struct window_pane *wp2)
{
        return (wp1->id - wp2->id);
}

struct winlink *
winlink_find_by_window(struct winlinks *wwl, struct window *w)
{
        struct winlink  *wl;

        RB_FOREACH(wl, winlinks, wwl) {
                if (wl->window == w)
                        return (wl);
        }

        return (NULL);
}

struct winlink *
winlink_find_by_index(struct winlinks *wwl, int idx)
{
        struct winlink  wl;

        if (idx < 0)
                fatalx("bad index");

        wl.idx = idx;
        return (RB_FIND(winlinks, wwl, &wl));
}

struct winlink *
winlink_find_by_window_id(struct winlinks *wwl, u_int id)
{
        struct winlink *wl;

        RB_FOREACH(wl, winlinks, wwl) {
                if (wl->window->id == id)
                        return (wl);
        }
        return (NULL);
}

static int
winlink_next_index(struct winlinks *wwl, int idx)
{
        int     i;

        i = idx;
        do {
                if (winlink_find_by_index(wwl, i) == NULL)
                        return (i);
                if (i == INT_MAX)
                        i = 0;
                else
                        i++;
        } while (i != idx);
        return (-1);
}

u_int
winlink_count(struct winlinks *wwl)
{
        struct winlink  *wl;
        u_int            n;

        n = 0;
        RB_FOREACH(wl, winlinks, wwl)
                n++;

        return (n);
}

struct winlink *
winlink_add(struct winlinks *wwl, int idx)
{
        struct winlink  *wl;

        if (idx < 0) {
                if ((idx = winlink_next_index(wwl, -idx - 1)) == -1)
                        return (NULL);
        } else if (winlink_find_by_index(wwl, idx) != NULL)
                return (NULL);

        wl = xcalloc(1, sizeof *wl);
        wl->idx = idx;
        RB_INSERT(winlinks, wwl, wl);

        return (wl);
}

void
winlink_set_window(struct winlink *wl, struct window *w)
{
        if (wl->window != NULL) {
                TAILQ_REMOVE(&wl->window->winlinks, wl, wentry);
                window_remove_ref(wl->window, __func__);
        }
        TAILQ_INSERT_TAIL(&w->winlinks, wl, wentry);
        wl->window = w;
        window_add_ref(w, __func__);
}

void
winlink_remove(struct winlinks *wwl, struct winlink *wl)
{
        struct window   *w = wl->window;

        if (w != NULL) {
                TAILQ_REMOVE(&w->winlinks, wl, wentry);
                window_remove_ref(w, __func__);
        }

        RB_REMOVE(winlinks, wwl, wl);
        free(wl);
}

struct winlink *
winlink_next(struct winlink *wl)
{
        return (RB_NEXT(winlinks, wwl, wl));
}

struct winlink *
winlink_previous(struct winlink *wl)
{
        return (RB_PREV(winlinks, wwl, wl));
}

struct winlink *
winlink_next_by_number(struct winlink *wl, struct session *s, int n)
{
        for (; n > 0; n--) {
                if ((wl = RB_NEXT(winlinks, wwl, wl)) == NULL)
                        wl = RB_MIN(winlinks, &s->windows);
        }

        return (wl);
}

struct winlink *
winlink_previous_by_number(struct winlink *wl, struct session *s, int n)
{
        for (; n > 0; n--) {
                if ((wl = RB_PREV(winlinks, wwl, wl)) == NULL)
                        wl = RB_MAX(winlinks, &s->windows);
        }

        return (wl);
}

void
winlink_stack_push(struct winlink_stack *stack, struct winlink *wl)
{
        if (wl == NULL)
                return;

        winlink_stack_remove(stack, wl);
        TAILQ_INSERT_HEAD(stack, wl, sentry);
        wl->flags |= WINLINK_VISITED;
}

void
winlink_stack_remove(struct winlink_stack *stack, struct winlink *wl)
{
        if (wl != NULL && (wl->flags & WINLINK_VISITED)) {
                TAILQ_REMOVE(stack, wl, sentry);
                wl->flags &= ~WINLINK_VISITED;
        }
}

struct window *
window_find_by_id_str(const char *s)
{
        const char      *errstr;
        u_int            id;

        if (*s != '@')
                return (NULL);

        id = strtonum(s + 1, 0, UINT_MAX, &errstr);
        if (errstr != NULL)
                return (NULL);
        return (window_find_by_id(id));
}

struct window *
window_find_by_id(u_int id)
{
        struct window   w;

        w.id = id;
        return (RB_FIND(windows, &windows, &w));
}

void
window_update_activity(struct window *w)
{
        gettimeofday(&w->activity_time, NULL);
        alerts_queue(w, WINDOW_ACTIVITY);
}

struct window *
window_create(u_int sx, u_int sy, u_int xpixel, u_int ypixel)
{
        struct window   *w;

        if (xpixel == 0)
                xpixel = DEFAULT_XPIXEL;
        if (ypixel == 0)
                ypixel = DEFAULT_YPIXEL;

        w = xcalloc(1, sizeof *w);
        w->name = xstrdup("");
        w->flags = 0;

        TAILQ_INIT(&w->panes);
        TAILQ_INIT(&w->last_panes);
        w->active = NULL;

        w->lastlayout = -1;
        w->layout_root = NULL;

        w->sx = sx;
        w->sy = sy;
        w->manual_sx = sx;
        w->manual_sy = sy;
        w->xpixel = xpixel;
        w->ypixel = ypixel;

        w->options = options_create(global_w_options);

        w->references = 0;
        TAILQ_INIT(&w->winlinks);

        w->id = next_window_id++;
        RB_INSERT(windows, &windows, w);

        window_set_fill_character(w);

        if (gettimeofday(&w->creation_time, NULL) != 0)
                fatal("gettimeofday failed");
        window_update_activity(w);

        log_debug("%s: @%u create %ux%u (%ux%u)", __func__, w->id, sx, sy,
            w->xpixel, w->ypixel);
        return (w);
}

static void
window_destroy(struct window *w)
{
        log_debug("window @%u destroyed (%d references)", w->id, w->references);

        window_unzoom(w, 0);
        RB_REMOVE(windows, &windows, w);

        if (w->layout_root != NULL)
                layout_free_cell(w->layout_root);
        if (w->saved_layout_root != NULL)
                layout_free_cell(w->saved_layout_root);
        free(w->old_layout);

        window_destroy_panes(w);

        if (event_initialized(&w->name_event))
                evtimer_del(&w->name_event);

        if (event_initialized(&w->alerts_timer))
                evtimer_del(&w->alerts_timer);
        if (event_initialized(&w->offset_timer))
                event_del(&w->offset_timer);

        options_free(w->options);
        free(w->fill_character);

        free(w->name);
        free(w);
}

int
window_pane_destroy_ready(struct window_pane *wp)
{
        int     n;

        if (wp->pipe_fd != -1) {
                if (EVBUFFER_LENGTH(wp->pipe_event->output) != 0)
                        return (0);
                if (ioctl(wp->fd, FIONREAD, &n) != -1 && n > 0)
                        return (0);
        }

        if (~wp->flags & PANE_EXITED)
                return (0);
        return (1);
}

void
window_add_ref(struct window *w, const char *from)
{
        w->references++;
        log_debug("%s: @%u %s, now %d", __func__, w->id, from, w->references);
}

void
window_remove_ref(struct window *w, const char *from)
{
        w->references--;
        log_debug("%s: @%u %s, now %d", __func__, w->id, from, w->references);

        if (w->references == 0)
                window_destroy(w);
}

void
window_set_name(struct window *w, const char *new_name)
{
        free(w->name);
        utf8_stravis(&w->name, new_name, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
        notify_window("window-renamed", w);
}

void
window_resize(struct window *w, u_int sx, u_int sy, int xpixel, int ypixel)
{
        if (xpixel == 0)
                xpixel = DEFAULT_XPIXEL;
        if (ypixel == 0)
                ypixel = DEFAULT_YPIXEL;

        log_debug("%s: @%u resize %ux%u (%ux%u)", __func__, w->id, sx, sy,
            xpixel == -1 ? w->xpixel : (u_int)xpixel,
            ypixel == -1 ? w->ypixel : (u_int)ypixel);
        w->sx = sx;
        w->sy = sy;
        if (xpixel != -1)
                w->xpixel = xpixel;
        if (ypixel != -1)
                w->ypixel = ypixel;
}

void
window_pane_send_resize(struct window_pane *wp, u_int sx, u_int sy)
{
        struct window   *w = wp->window;
        struct winsize   ws;

        if (wp->fd == -1)
                return;

        log_debug("%s: %%%u resize to %u,%u", __func__, wp->id, sx, sy);

        memset(&ws, 0, sizeof ws);
        ws.ws_col = sx;
        ws.ws_row = sy;
        ws.ws_xpixel = w->xpixel * ws.ws_col;
        ws.ws_ypixel = w->ypixel * ws.ws_row;
        if (ioctl(wp->fd, TIOCSWINSZ, &ws) == -1)
                fatal("ioctl failed");
}

int
window_has_pane(struct window *w, struct window_pane *wp)
{
        struct window_pane      *wp1;

        TAILQ_FOREACH(wp1, &w->panes, entry) {
                if (wp1 == wp)
                        return (1);
        }
        return (0);
}

void
window_update_focus(struct window *w)
{
        if (w != NULL) {
                log_debug("%s: @%u", __func__, w->id);
                window_pane_update_focus(w->active);
        }
}

void
window_pane_update_focus(struct window_pane *wp)
{
        struct client   *c;
        int              focused = 0;

        if (wp != NULL && (~wp->flags & PANE_EXITED)) {
                if (wp != wp->window->active)
                        focused = 0;
                else {
                        TAILQ_FOREACH(c, &clients, entry) {
                                if (c->session != NULL &&
                                    c->session->attached != 0 &&
                                    (c->flags & CLIENT_FOCUSED) &&
                                    c->session->curw->window == wp->window &&
                                    c->overlay_draw == NULL) {
                                        focused = 1;
                                        break;
                                }
                        }
                }
                if (!focused && (wp->flags & PANE_FOCUSED)) {
                        log_debug("%s: %%%u focus out", __func__, wp->id);
                        if (wp->base.mode & MODE_FOCUSON)
                                bufferevent_write(wp->event, "\033[O", 3);
                        notify_pane("pane-focus-out", wp);
                        wp->flags &= ~PANE_FOCUSED;
                } else if (focused && (~wp->flags & PANE_FOCUSED)) {
                        log_debug("%s: %%%u focus in", __func__, wp->id);
                        if (wp->base.mode & MODE_FOCUSON)
                                bufferevent_write(wp->event, "\033[I", 3);
                        notify_pane("pane-focus-in", wp);
                        wp->flags |= PANE_FOCUSED;
                } else
                        log_debug("%s: %%%u focus unchanged", __func__, wp->id);
        }
}

int
window_set_active_pane(struct window *w, struct window_pane *wp, int notify)
{
        struct window_pane *lastwp;

        log_debug("%s: pane %%%u", __func__, wp->id);

        if (wp == w->active)
                return (0);
        lastwp = w->active;

        window_pane_stack_remove(&w->last_panes, wp);
        window_pane_stack_push(&w->last_panes, lastwp);

        w->active = wp;
        w->active->active_point = next_active_point++;
        w->active->flags |= PANE_CHANGED;

        if (options_get_number(global_options, "focus-events")) {
                window_pane_update_focus(lastwp);
                window_pane_update_focus(w->active);
        }

        tty_update_window_offset(w);

        if (notify)
                notify_window("window-pane-changed", w);
        return (1);
}

static int
window_pane_get_palette(struct window_pane *wp, int c)
{
        if (wp == NULL)
                return (-1);
        return (colour_palette_get(&wp->palette, c));
}

void
window_redraw_active_switch(struct window *w, struct window_pane *wp)
{
        struct grid_cell        *gc1, *gc2;
        int                      c1, c2;

        if (wp == w->active)
                return;

        for (;;) {
                /*
                 * If the active and inactive styles or palettes are different,
                 * need to redraw the panes.
                 */
                gc1 = &wp->cached_gc;
                gc2 = &wp->cached_active_gc;
                if (!grid_cells_look_equal(gc1, gc2))
                        wp->flags |= PANE_REDRAW;
                else {
                        c1 = window_pane_get_palette(wp, gc1->fg);
                        c2 = window_pane_get_palette(wp, gc2->fg);
                        if (c1 != c2)
                                wp->flags |= PANE_REDRAW;
                        else {
                                c1 = window_pane_get_palette(wp, gc1->bg);
                                c2 = window_pane_get_palette(wp, gc2->bg);
                                if (c1 != c2)
                                        wp->flags |= PANE_REDRAW;
                        }
                }
                if (wp == w->active)
                        break;
                wp = w->active;
        }
}

struct window_pane *
window_get_active_at(struct window *w, u_int x, u_int y)
{
        struct window_pane      *wp;
        int                      pane_status, xoff, yoff;
        u_int                    sx, sy;

        pane_status = options_get_number(w->options, "pane-border-status");

        TAILQ_FOREACH(wp, &w->panes, entry) {
                if (!window_pane_visible(wp))
                        continue;
                window_pane_full_size_offset(wp, &xoff, &yoff, &sx, &sy);
                if ((int)x < xoff || x > xoff + sx)
                        continue;
                if (pane_status == PANE_STATUS_TOP) {
                        if ((int)y <= yoff - 2 || y > yoff + sy - 1)
                                continue;
                } else {
                        if ((int)y < yoff || y > yoff + sy)
                                continue;
                }
                return (wp);
        }
        return (NULL);
}

struct window_pane *
window_find_string(struct window *w, const char *s)
{
        u_int   x, y, top = 0, bottom = w->sy - 1;
        int     status;

        x = w->sx / 2;
        y = w->sy / 2;

        status = options_get_number(w->options, "pane-border-status");
        if (status == PANE_STATUS_TOP)
                top++;
        else if (status == PANE_STATUS_BOTTOM)
                bottom--;

        if (strcasecmp(s, "top") == 0)
                y = top;
        else if (strcasecmp(s, "bottom") == 0)
                y = bottom;
        else if (strcasecmp(s, "left") == 0)
                x = 0;
        else if (strcasecmp(s, "right") == 0)
                x = w->sx - 1;
        else if (strcasecmp(s, "top-left") == 0) {
                x = 0;
                y = top;
        } else if (strcasecmp(s, "top-right") == 0) {
                x = w->sx - 1;
                y = top;
        } else if (strcasecmp(s, "bottom-left") == 0) {
                x = 0;
                y = bottom;
        } else if (strcasecmp(s, "bottom-right") == 0) {
                x = w->sx - 1;
                y = bottom;
        } else
                return (NULL);

        return (window_get_active_at(w, x, y));
}

int
window_zoom(struct window_pane *wp)
{
        struct window           *w = wp->window;
        struct window_pane      *wp1;

        if (w->flags & WINDOW_ZOOMED)
                return (-1);

        if (window_count_panes(w) == 1)
                return (-1);

        if (w->active != wp)
                window_set_active_pane(w, wp, 1);
        wp->flags |= PANE_ZOOMED;

        TAILQ_FOREACH(wp1, &w->panes, entry) {
                wp1->saved_layout_cell = wp1->layout_cell;
                wp1->layout_cell = NULL;
        }

        w->saved_layout_root = w->layout_root;
        layout_init(w, wp);
        w->flags |= WINDOW_ZOOMED;
        notify_window("window-layout-changed", w);

        return (0);
}

int
window_unzoom(struct window *w, int notify)
{
        struct window_pane      *wp;

        if (!(w->flags & WINDOW_ZOOMED))
                return (-1);

        w->flags &= ~WINDOW_ZOOMED;
        layout_free(w);
        w->layout_root = w->saved_layout_root;
        w->saved_layout_root = NULL;

        TAILQ_FOREACH(wp, &w->panes, entry) {
                wp->layout_cell = wp->saved_layout_cell;
                wp->saved_layout_cell = NULL;
                wp->flags ^= PANE_ZOOMED;
        }
        layout_fix_panes(w, NULL);

        if (notify)
                notify_window("window-layout-changed", w);

        return (0);
}

int
window_push_zoom(struct window *w, int always, int flag)
{
        log_debug("%s: @%u %d", __func__, w->id,
            flag && (w->flags & WINDOW_ZOOMED));
        if (flag && (always || (w->flags & WINDOW_ZOOMED)))
                w->flags |= WINDOW_WASZOOMED;
        else
                w->flags &= ~WINDOW_WASZOOMED;
        return (window_unzoom(w, 1) == 0);
}

int
window_pop_zoom(struct window *w)
{
        log_debug("%s: @%u %d", __func__, w->id,
            !!(w->flags & WINDOW_WASZOOMED));
        if (w->flags & WINDOW_WASZOOMED)
                return (window_zoom(w->active) == 0);
        return (0);
}

struct window_pane *
window_add_pane(struct window *w, struct window_pane *other, u_int hlimit,
    int flags)
{
        struct window_pane      *wp;

        if (other == NULL)
                other = w->active;

        wp = window_pane_create(w, w->sx, w->sy, hlimit);
        if (TAILQ_EMPTY(&w->panes)) {
                log_debug("%s: @%u at start", __func__, w->id);
                TAILQ_INSERT_HEAD(&w->panes, wp, entry);
        } else if (flags & SPAWN_BEFORE) {
                log_debug("%s: @%u before %%%u", __func__, w->id, wp->id);
                if (flags & SPAWN_FULLSIZE)
                        TAILQ_INSERT_HEAD(&w->panes, wp, entry);
                else
                        TAILQ_INSERT_BEFORE(other, wp, entry);
        } else {
                log_debug("%s: @%u after %%%u", __func__, w->id, wp->id);
                if (flags & SPAWN_FULLSIZE)
                        TAILQ_INSERT_TAIL(&w->panes, wp, entry);
                else
                        TAILQ_INSERT_AFTER(&w->panes, other, wp, entry);
        }
        return (wp);
}

void
window_lost_pane(struct window *w, struct window_pane *wp)
{
        log_debug("%s: @%u pane %%%u", __func__, w->id, wp->id);

        if (wp == marked_pane.wp)
                server_clear_marked();

        window_pane_stack_remove(&w->last_panes, wp);
        if (wp == w->active) {
                w->active = TAILQ_FIRST(&w->last_panes);
                if (w->active == NULL) {
                        w->active = TAILQ_PREV(wp, window_panes, entry);
                        if (w->active == NULL)
                                w->active = TAILQ_NEXT(wp, entry);
                }
                if (w->active != NULL) {
                        window_pane_stack_remove(&w->last_panes, w->active);
                        w->active->flags |= PANE_CHANGED;
                        notify_window("window-pane-changed", w);
                        window_update_focus(w);
                }
        }
}

void
window_remove_pane(struct window *w, struct window_pane *wp)
{
        window_lost_pane(w, wp);

        TAILQ_REMOVE(&w->panes, wp, entry);
        window_pane_destroy(wp);
}

struct window_pane *
window_pane_at_index(struct window *w, u_int idx)
{
        struct window_pane      *wp;
        u_int                    n;

        n = options_get_number(w->options, "pane-base-index");
        TAILQ_FOREACH(wp, &w->panes, entry) {
                if (n == idx)
                        return (wp);
                n++;
        }
        return (NULL);
}

struct window_pane *
window_pane_next_by_number(struct window *w, struct window_pane *wp, u_int n)
{
        for (; n > 0; n--) {
                if ((wp = TAILQ_NEXT(wp, entry)) == NULL)
                        wp = TAILQ_FIRST(&w->panes);
        }

        return (wp);
}

struct window_pane *
window_pane_previous_by_number(struct window *w, struct window_pane *wp,
    u_int n)
{
        for (; n > 0; n--) {
                if ((wp = TAILQ_PREV(wp, window_panes, entry)) == NULL)
                        wp = TAILQ_LAST(&w->panes, window_panes);
        }

        return (wp);
}

int
window_pane_index(struct window_pane *wp, u_int *i)
{
        struct window_pane      *wq;
        struct window           *w = wp->window;

        *i = options_get_number(w->options, "pane-base-index");
        TAILQ_FOREACH(wq, &w->panes, entry) {
                if (wp == wq) {
                        return (0);
                }
                (*i)++;
        }

        return (-1);
}

u_int
window_count_panes(struct window *w)
{
        struct window_pane      *wp;
        u_int                    n;

        n = 0;
        TAILQ_FOREACH(wp, &w->panes, entry)
                n++;
        return (n);
}

void
window_destroy_panes(struct window *w)
{
        struct window_pane      *wp;

        while (!TAILQ_EMPTY(&w->last_panes)) {
                wp = TAILQ_FIRST(&w->last_panes);
                window_pane_stack_remove(&w->last_panes, wp);
        }

        while (!TAILQ_EMPTY(&w->panes)) {
                wp = TAILQ_FIRST(&w->panes);
                TAILQ_REMOVE(&w->panes, wp, entry);
                window_pane_destroy(wp);
        }
}

const char *
window_printable_flags(struct winlink *wl, int escape)
{
        struct session  *s = wl->session;
        static char      flags[32];
        u_int            pos = 0;

        if (wl->flags & WINLINK_ACTIVITY) {
                flags[pos++] = '#';
                if (escape)
                        flags[pos++] = '#';
        }
        if (wl->flags & WINLINK_BELL)
                flags[pos++] = '!';
        if (wl->flags & WINLINK_SILENCE)
                flags[pos++] = '~';
        if (wl == s->curw)
                flags[pos++] = '*';
        if (wl == TAILQ_FIRST(&s->lastw))
                flags[pos++] = '-';
        if (server_check_marked() && wl == marked_pane.wl)
                flags[pos++] = 'M';
        if (wl->window->flags & WINDOW_ZOOMED)
                flags[pos++] = 'Z';
        flags[pos] = '\0';
        return (flags);
}

const char *
window_pane_printable_flags(struct window_pane *wp)
{
        struct window   *w = wp->window;
        static char      flags[32];
        u_int            pos = 0;

        if (wp == w->active)
                flags[pos++] = '*';
        if (wp == TAILQ_FIRST(&w->last_panes))
                flags[pos++] = '-';
        if (wp->flags & PANE_ZOOMED)
                flags[pos++] = 'Z';
        if (wp->flags & PANE_FLOATING)
                flags[pos++] = 'F';
        flags[pos] = '\0';
        return (flags);
}

struct window_pane *
window_pane_find_by_id_str(const char *s)
{
        const char      *errstr;
        u_int            id;

        if (*s != '%')
                return (NULL);

        id = strtonum(s + 1, 0, UINT_MAX, &errstr);
        if (errstr != NULL)
                return (NULL);
        return (window_pane_find_by_id(id));
}

struct window_pane *
window_pane_find_by_id(u_int id)
{
        struct window_pane      wp;

        wp.id = id;
        return (RB_FIND(window_pane_tree, &all_window_panes, &wp));
}

static struct window_pane *
window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
{
        struct window_pane      *wp;
        char                     host[HOST_NAME_MAX + 1];

        wp = xcalloc(1, sizeof *wp);
        wp->window = w;
        wp->options = options_create(w->options);
        wp->flags = PANE_STYLECHANGED;

        wp->id = next_window_pane_id++;
        RB_INSERT(window_pane_tree, &all_window_panes, wp);

        wp->fd = -1;

        TAILQ_INIT(&wp->modes);

        TAILQ_INIT (&wp->resize_queue);

        wp->sx = sx;
        wp->sy = sy;

        wp->pipe_fd = -1;

        wp->control_bg = -1;
        wp->control_fg = -1;

        style_set_scrollbar_style_from_option(&wp->scrollbar_style,
            wp->options);

        colour_palette_init(&wp->palette);
        colour_palette_from_option(&wp->palette, wp->options);

        screen_init(&wp->base, sx, sy, hlimit);
        wp->screen = &wp->base;
        window_pane_default_cursor(wp);

        screen_init(&wp->status_screen, 1, 1, 0);
        style_ranges_init(&wp->border_status_line.ranges);

        if (gethostname(host, sizeof host) == 0)
                screen_set_title(&wp->base, host);

        return (wp);
}

static void
window_pane_destroy(struct window_pane *wp)
{
        struct window_pane_resize       *r;
        struct window_pane_resize       *r1;

        window_pane_reset_mode_all(wp);
        free(wp->searchstr);

        if (wp->fd != -1) {
                bufferevent_free(wp->event);
                close(wp->fd);
        }
        if (wp->ictx != NULL)
                input_free(wp->ictx);

        screen_free(&wp->status_screen);

        screen_free(&wp->base);

        if (wp->pipe_fd != -1) {
                bufferevent_free(wp->pipe_event);
                close(wp->pipe_fd);
        }

        if (event_initialized(&wp->resize_timer))
                event_del(&wp->resize_timer);
        if (event_initialized(&wp->sync_timer))
                event_del(&wp->sync_timer);
        TAILQ_FOREACH_SAFE(r, &wp->resize_queue, entry, r1) {
                TAILQ_REMOVE(&wp->resize_queue, r, entry);
                free(r);
        }

        RB_REMOVE(window_pane_tree, &all_window_panes, wp);

        options_free(wp->options);
        free((void *)wp->cwd);
        free(wp->shell);
        cmd_free_argv(wp->argc, wp->argv);
        colour_palette_free(&wp->palette);
        style_ranges_free(&wp->border_status_line.ranges);
        free(wp);
}

static void
window_pane_read_callback(__unused struct bufferevent *bufev, void *data)
{
        struct window_pane              *wp = data;
        struct evbuffer                 *evb = wp->event->input;
        struct window_pane_offset       *wpo = &wp->pipe_offset;
        size_t                           size = EVBUFFER_LENGTH(evb);
        char                            *new_data;
        size_t                           new_size;
        struct client                   *c;

        if (wp->pipe_fd != -1) {
                new_data = window_pane_get_new_data(wp, wpo, &new_size);
                if (new_size > 0) {
                        bufferevent_write(wp->pipe_event, new_data, new_size);
                        window_pane_update_used_data(wp, wpo, new_size);
                }
        }

        log_debug("%%%u has %zu bytes", wp->id, size);
        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session != NULL && (c->flags & CLIENT_CONTROL))
                        control_write_output(c, wp);
        }
        input_parse_pane(wp);
        bufferevent_disable(wp->event, EV_READ);
}

static void
window_pane_error_callback(__unused struct bufferevent *bufev,
    __unused short what, void *data)
{
        struct window_pane *wp = data;

        log_debug("%%%u error", wp->id);
        wp->flags |= PANE_EXITED;

        if (window_pane_destroy_ready(wp))
                server_destroy_pane(wp, 1);
}

void
window_pane_set_event(struct window_pane *wp)
{
        setblocking(wp->fd, 0);

        wp->event = bufferevent_new(wp->fd, window_pane_read_callback,
            NULL, window_pane_error_callback, wp);
        if (wp->event == NULL)
                fatalx("out of memory");
        wp->ictx = input_init(wp, wp->event, &wp->palette, NULL);

        bufferevent_enable(wp->event, EV_READ|EV_WRITE);
}

void
window_pane_resize(struct window_pane *wp, u_int sx, u_int sy)
{
        struct window_mode_entry        *wme;
        struct window_pane_resize       *r;

        if (sx == wp->sx && sy == wp->sy)
                return;

        screen_write_stop_sync(wp);

        r = xmalloc(sizeof *r);
        r->sx = sx;
        r->sy = sy;
        r->osx = wp->sx;
        r->osy = wp->sy;
        TAILQ_INSERT_TAIL (&wp->resize_queue, r, entry);

        wp->sx = sx;
        wp->sy = sy;

        log_debug("%s: %%%u resize %ux%u", __func__, wp->id, sx, sy);
        screen_resize(&wp->base, sx, sy, wp->base.saved_grid == NULL);

        wme = TAILQ_FIRST(&wp->modes);
        if (wme != NULL && wme->mode->resize != NULL)
                wme->mode->resize(wme, sx, sy);
}

int
window_pane_set_mode(struct window_pane *wp, struct window_pane *swp,
    const struct window_mode *mode, struct cmd_find_state *fs,
    struct args *args)
{
        struct window_mode_entry        *wme;
        struct window                   *w = wp->window;

        if (!TAILQ_EMPTY(&wp->modes) && TAILQ_FIRST(&wp->modes)->mode == mode)
                return (1);

        TAILQ_FOREACH(wme, &wp->modes, entry) {
                if (wme->mode == mode)
                        break;
        }
        if (wme != NULL) {
                TAILQ_REMOVE(&wp->modes, wme, entry);
                TAILQ_INSERT_HEAD(&wp->modes, wme, entry);
        } else {
                wme = xcalloc(1, sizeof *wme);
                wme->wp = wp;
                wme->swp = swp;
                wme->mode = mode;
                wme->prefix = 1;
                TAILQ_INSERT_HEAD(&wp->modes, wme, entry);
                wme->screen = wme->mode->init(wme, fs, args);
        }
        wp->screen = wme->screen;

        wp->flags |= (PANE_REDRAW|PANE_REDRAWSCROLLBAR|PANE_CHANGED);
        layout_fix_panes(w, NULL);

        server_redraw_window_borders(wp->window);
        server_status_window(wp->window);
        notify_pane("pane-mode-changed", wp);

        return (0);
}

void
window_pane_reset_mode(struct window_pane *wp)
{
        struct window_mode_entry        *wme, *next;
        struct window                   *w = wp->window;

        if (TAILQ_EMPTY(&wp->modes))
                return;

        wme = TAILQ_FIRST(&wp->modes);
        TAILQ_REMOVE(&wp->modes, wme, entry);
        wme->mode->free(wme);
        free(wme);

        next = TAILQ_FIRST(&wp->modes);
        if (next == NULL) {
                wp->flags &= ~PANE_UNSEENCHANGES;
                log_debug("%s: no next mode", __func__);
                wp->screen = &wp->base;
        } else {
                log_debug("%s: next mode is %s", __func__, next->mode->name);
                wp->screen = next->screen;
                if (next->mode->resize != NULL)
                        next->mode->resize(next, wp->sx, wp->sy);
        }

        wp->flags |= (PANE_REDRAW|PANE_REDRAWSCROLLBAR|PANE_CHANGED);
        layout_fix_panes(w, NULL);

        server_redraw_window_borders(wp->window);
        server_status_window(wp->window);
        notify_pane("pane-mode-changed", wp);
}

void
window_pane_reset_mode_all(struct window_pane *wp)
{
        while (!TAILQ_EMPTY(&wp->modes))
                window_pane_reset_mode(wp);
}

static void
window_pane_copy_paste(struct window_pane *wp, char *buf, size_t len)
{
        struct window_pane      *loop;

        TAILQ_FOREACH(loop, &wp->window->panes, entry) {
                if (loop != wp &&
                    TAILQ_EMPTY(&loop->modes) &&
                    loop->fd != -1 &&
                    (~loop->flags & PANE_INPUTOFF) &&
                    window_pane_visible(loop) &&
                    options_get_number(loop->options, "synchronize-panes")) {
                        log_debug("%s: %.*s", __func__, (int)len, buf);
                        bufferevent_write(loop->event, buf, len);
                }
        }
}

static void
window_pane_copy_key(struct window_pane *wp, key_code key)
{
        struct window_pane      *loop;

        TAILQ_FOREACH(loop, &wp->window->panes, entry) {
                if (loop != wp &&
                    TAILQ_EMPTY(&loop->modes) &&
                    loop->fd != -1 &&
                    (~loop->flags & PANE_INPUTOFF) &&
                    window_pane_visible(loop) &&
                    options_get_number(loop->options, "synchronize-panes"))
                        input_key_pane(loop, key, NULL);
        }
}

void
window_pane_paste(struct window_pane *wp, key_code key, char *buf, size_t len)
{
        if (!TAILQ_EMPTY(&wp->modes))
                return;

        if (wp->fd == -1 || wp->flags & PANE_INPUTOFF)
                return;

        if (KEYC_IS_PASTE(key) && (~wp->screen->mode & MODE_BRACKETPASTE))
                return;

        log_debug("%s: %.*s", __func__, (int)len, buf);
        bufferevent_write(wp->event, buf, len);

        if (options_get_number(wp->options, "synchronize-panes"))
                window_pane_copy_paste(wp, buf, len);
}

int
window_pane_key(struct window_pane *wp, struct client *c, struct session *s,
    struct winlink *wl, key_code key, struct mouse_event *m)
{
        struct window_mode_entry        *wme;

        if (KEYC_IS_MOUSE(key) && m == NULL)
                return (-1);

        wme = TAILQ_FIRST(&wp->modes);
        if (wme != NULL) {
                if (wme->mode->key != NULL && c != NULL) {
                        key &= ~KEYC_MASK_FLAGS;
                        wme->mode->key(wme, c, s, wl, key, m);
                }
                return (0);
        }

        if (wp->fd == -1 || wp->flags & PANE_INPUTOFF)
                return (0);

        if (input_key_pane(wp, key, m) != 0)
                return (-1);

        if (KEYC_IS_MOUSE(key))
                return (0);
        if (options_get_number(wp->options, "synchronize-panes"))
                window_pane_copy_key(wp, key);
        return (0);
}

int
window_pane_visible(struct window_pane *wp)
{
        if (~wp->window->flags & WINDOW_ZOOMED)
                return (1);
        return (wp == wp->window->active);
}

int
window_pane_exited(struct window_pane *wp)
{
        return (wp->fd == -1 || (wp->flags & PANE_EXITED));
}

u_int
window_pane_search(struct window_pane *wp, const char *term, int regex,
    int ignore)
{
        struct screen   *s = &wp->base;
        regex_t          r;
        char            *new = NULL, *line;
        u_int            i;
        int              flags = 0, found;
        size_t           n;

        if (!regex) {
                if (ignore)
                        flags |= FNM_CASEFOLD;
                xasprintf(&new, "*%s*", term);
        } else {
                if (ignore)
                        flags |= REG_ICASE;
                if (regcomp(&r, term, flags|REG_EXTENDED) != 0)
                        return (0);
        }

        for (i = 0; i < screen_size_y(s); i++) {
                line = grid_view_string_cells(s->grid, 0, i, screen_size_x(s));
                for (n = strlen(line); n > 0; n--) {
                        if (!isspace((u_char)line[n - 1]))
                                break;
                        line[n - 1] = '\0';
                }
                log_debug("%s: %s", __func__, line);
                if (!regex)
                        found = (fnmatch(new, line, flags) == 0);
                else
                        found = (regexec(&r, line, 0, NULL, 0) == 0);
                free(line);
                if (found)
                        break;
        }
        if (!regex)
                free(new);
        else
                regfree(&r);

        if (i == screen_size_y(s))
                return (0);
        return (i + 1);
}

/* Get MRU pane from a list. */
static struct window_pane *
window_pane_choose_best(struct window_pane **list, u_int size)
{
        struct window_pane      *next, *best;
        u_int                    i;

        if (size == 0)
                return (NULL);

        best = list[0];
        for (i = 1; i < size; i++) {
                next = list[i];
                if (next->active_point > best->active_point)
                        best = next;
        }
        return (best);
}

/*
 * Get full size and offset of a window pane including the area of the
 * scrollbars if they were visible but not including the border(s).
 */
static void
window_pane_full_size_offset(struct window_pane *wp, u_int *xoff, u_int *yoff,
    u_int *sx, u_int *sy)
{
        struct window           *w = wp->window;
        int                      pane_scrollbars;
        u_int                    sb_w, sb_pos;

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

        if (window_pane_show_scrollbar(wp, pane_scrollbars))
                sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
        else
                sb_w = 0;
        if (sb_pos == PANE_SCROLLBARS_LEFT) {
                *xoff = wp->xoff - sb_w;
                *sx = wp->sx + sb_w;
        } else { /* sb_pos == PANE_SCROLLBARS_RIGHT */
                *xoff = wp->xoff;
                *sx = wp->sx + sb_w;
        }
        *yoff = wp->yoff;
        *sy = wp->sy;
}

/*
 * Find the pane directly above another. We build a list of those adjacent to
 * top edge and then choose the best.
 */
struct window_pane *
window_pane_find_up(struct window_pane *wp)
{
        struct window           *w;
        struct window_pane      *next, *best, **list;
        u_int                    edge, left, right, end, size;
        int                      status, found;
        u_int                    xoff, yoff, sx, sy;

        if (wp == NULL)
                return (NULL);
        w = wp->window;
        status = options_get_number(w->options, "pane-border-status");

        list = NULL;
        size = 0;

        window_pane_full_size_offset(wp, &xoff, &yoff, &sx, &sy);

        edge = yoff;
        if (status == PANE_STATUS_TOP) {
                if (edge == 1)
                        edge = w->sy + 1;
        } else if (status == PANE_STATUS_BOTTOM) {
                if (edge == 0)
                        edge = w->sy;
        } else {
                if (edge == 0)
                        edge = w->sy + 1;
        }

        left = xoff;
        right = xoff + sx;

        TAILQ_FOREACH(next, &w->panes, entry) {
                window_pane_full_size_offset(next, &xoff, &yoff, &sx, &sy);
                if (next == wp)
                        continue;
                if (yoff + sy + 1 != edge)
                        continue;
                end = xoff + sx - 1;

                found = 0;
                if (xoff < left && end > right)
                        found = 1;
                else if (xoff >= left && xoff <= right)
                        found = 1;
                else if (end >= left && end <= right)
                        found = 1;
                if (!found)
                        continue;
                list = xreallocarray(list, size + 1, sizeof *list);
                list[size++] = next;
        }

        best = window_pane_choose_best(list, size);
        free(list);
        return (best);
}

/* Find the pane directly below another. */
struct window_pane *
window_pane_find_down(struct window_pane *wp)
{
        struct window           *w;
        struct window_pane      *next, *best, **list;
        u_int                    edge, left, right, end, size;
        int                      status, found;
        u_int                    xoff, yoff, sx, sy;

        if (wp == NULL)
                return (NULL);
        w = wp->window;
        status = options_get_number(w->options, "pane-border-status");

        list = NULL;
        size = 0;

        window_pane_full_size_offset(wp, &xoff, &yoff, &sx, &sy);

        edge = yoff + sy + 1;
        if (status == PANE_STATUS_TOP) {
                if (edge >= w->sy)
                        edge = 1;
        } else if (status == PANE_STATUS_BOTTOM) {
                if (edge >= w->sy - 1)
                        edge = 0;
        } else {
                if (edge >= w->sy)
                        edge = 0;
        }

        left = wp->xoff;
        right = wp->xoff + wp->sx;

        TAILQ_FOREACH(next, &w->panes, entry) {
                window_pane_full_size_offset(next, &xoff, &yoff, &sx, &sy);
                if (next == wp)
                        continue;
                if (yoff != edge)
                        continue;
                end = xoff + sx - 1;

                found = 0;
                if (xoff < left && end > right)
                        found = 1;
                else if (xoff >= left && xoff <= right)
                        found = 1;
                else if (end >= left && end <= right)
                        found = 1;
                if (!found)
                        continue;
                list = xreallocarray(list, size + 1, sizeof *list);
                list[size++] = next;
        }

        best = window_pane_choose_best(list, size);
        free(list);
        return (best);
}

/* Find the pane directly to the left of another. */
struct window_pane *
window_pane_find_left(struct window_pane *wp)
{
        struct window           *w;
        struct window_pane      *next, *best, **list;
        u_int                    edge, top, bottom, end, size;
        int                      found;
        u_int                    xoff, yoff, sx, sy;

        if (wp == NULL)
                return (NULL);
        w = wp->window;

        list = NULL;
        size = 0;

        window_pane_full_size_offset(wp, &xoff, &yoff, &sx, &sy);

        edge = xoff;
        if (edge == 0)
                edge = w->sx + 1;

        top = yoff;
        bottom = yoff + sy;

        TAILQ_FOREACH(next, &w->panes, entry) {
                window_pane_full_size_offset(next, &xoff, &yoff, &sx, &sy);
                if (next == wp)
                        continue;
                if (xoff + sx + 1 != edge)
                        continue;
                end = yoff + sy - 1;

                found = 0;
                if (yoff < top && end > bottom)
                        found = 1;
                else if (yoff >= top && yoff <= bottom)
                        found = 1;
                else if (end >= top && end <= bottom)
                        found = 1;
                if (!found)
                        continue;
                list = xreallocarray(list, size + 1, sizeof *list);
                list[size++] = next;
        }

        best = window_pane_choose_best(list, size);
        free(list);
        return (best);
}

/* Find the pane directly to the right of another. */
struct window_pane *
window_pane_find_right(struct window_pane *wp)
{
        struct window           *w;
        struct window_pane      *next, *best, **list;
        u_int                    edge, top, bottom, end, size;
        int                      found;
        u_int                    xoff, yoff, sx, sy;

        if (wp == NULL)
                return (NULL);
        w = wp->window;

        list = NULL;
        size = 0;

        window_pane_full_size_offset(wp, &xoff, &yoff, &sx, &sy);

        edge = xoff + sx + 1;
        if (edge >= w->sx)
                edge = 0;

        top = wp->yoff;
        bottom = wp->yoff + wp->sy;

        TAILQ_FOREACH(next, &w->panes, entry) {
                window_pane_full_size_offset(next, &xoff, &yoff, &sx, &sy);
                if (next == wp)
                        continue;
                if (xoff != edge)
                        continue;
                end = yoff + sy - 1;

                found = 0;
                if (yoff < top && end > bottom)
                        found = 1;
                else if (yoff >= top && yoff <= bottom)
                        found = 1;
                else if (end >= top && end <= bottom)
                        found = 1;
                if (!found)
                        continue;
                list = xreallocarray(list, size + 1, sizeof *list);
                list[size++] = next;
        }

        best = window_pane_choose_best(list, size);
        free(list);
        return (best);
}

void
window_pane_stack_push(struct window_panes *stack, struct window_pane *wp)
{
        if (wp != NULL) {
                window_pane_stack_remove(stack, wp);
                TAILQ_INSERT_HEAD(stack, wp, sentry);
                wp->flags |= PANE_VISITED;
        }
}

void
window_pane_stack_remove(struct window_panes *stack, struct window_pane *wp)
{
        if (wp != NULL && (wp->flags & PANE_VISITED)) {
                TAILQ_REMOVE(stack, wp, sentry);
                wp->flags &= ~PANE_VISITED;
        }
}

/* Clear alert flags for a winlink */
void
winlink_clear_flags(struct winlink *wl)
{
        struct winlink  *loop;

        wl->window->flags &= ~WINDOW_ALERTFLAGS;
        TAILQ_FOREACH(loop, &wl->window->winlinks, wentry) {
                if ((loop->flags & WINLINK_ALERTFLAGS) != 0) {
                        loop->flags &= ~WINLINK_ALERTFLAGS;
                        server_status_session(loop->session);
                }
        }
}

/* Shuffle window indexes up. */
int
winlink_shuffle_up(struct session *s, struct winlink *wl, int before)
{
        int      idx, last;

        if (wl == NULL)
                return (-1);
        if (before)
                idx = wl->idx;
        else
                idx = wl->idx + 1;

        /* Find the next free index. */
        for (last = idx; last < INT_MAX; last++) {
                if (winlink_find_by_index(&s->windows, last) == NULL)
                        break;
        }
        if (last == INT_MAX)
                return (-1);

        /* Move everything from last - 1 to idx up a bit. */
        for (; last > idx; last--) {
                wl = winlink_find_by_index(&s->windows, last - 1);
                RB_REMOVE(winlinks, &s->windows, wl);
                wl->idx++;
                RB_INSERT(winlinks, &s->windows, wl);
        }

        return (idx);
}

static void
window_pane_input_callback(struct client *c, __unused const char *path,
    int error, int closed, struct evbuffer *buffer, void *data)
{
        struct window_pane_input_data   *cdata = data;
        struct window_pane              *wp;
        u_char                          *buf = EVBUFFER_DATA(buffer);
        size_t                           len = EVBUFFER_LENGTH(buffer);

        wp = window_pane_find_by_id(cdata->wp);
        if (cdata->file != NULL && (wp == NULL || c->flags & CLIENT_DEAD)) {
                if (wp == NULL) {
                        c->retval = 1;
                        c->flags |= CLIENT_EXIT;
                }
                file_cancel(cdata->file);
        } else if (cdata->file == NULL || closed || error != 0) {
                cmdq_continue(cdata->item);
                server_client_unref(c);
                free(cdata);
        } else
                input_parse_buffer(wp, buf, len);
        evbuffer_drain(buffer, len);
}

int
window_pane_start_input(struct window_pane *wp, struct cmdq_item *item,
    char **cause)
{
        struct client                   *c = cmdq_get_client(item);
        struct window_pane_input_data   *cdata;

        if (~wp->flags & PANE_EMPTY) {
                *cause = xstrdup("pane is not empty");
                return (-1);
        }
        if (c->flags & (CLIENT_DEAD|CLIENT_EXITED))
                return (1);
        if (c->session != NULL)
                return (1);

        cdata = xmalloc(sizeof *cdata);
        cdata->item = item;
        cdata->wp = wp->id;
        cdata->file = file_read(c, "-", window_pane_input_callback, cdata);
        c->references++;

        return (0);
}

void *
window_pane_get_new_data(struct window_pane *wp,
    struct window_pane_offset *wpo, size_t *size)
{
        size_t  used = wpo->used - wp->base_offset;

        *size = EVBUFFER_LENGTH(wp->event->input) - used;
        return (EVBUFFER_DATA(wp->event->input) + used);
}

void
window_pane_update_used_data(struct window_pane *wp,
    struct window_pane_offset *wpo, size_t size)
{
        size_t  used = wpo->used - wp->base_offset;

        if (size > EVBUFFER_LENGTH(wp->event->input) - used)
                size = EVBUFFER_LENGTH(wp->event->input) - used;
        wpo->used += size;
}

void
window_set_fill_character(struct window *w)
{
        const char              *value;
        struct utf8_data        *ud;

        free(w->fill_character);
        w->fill_character = NULL;

        value = options_get_string(w->options, "fill-character");
        if (*value != '\0' && utf8_isvalid(value)) {
                ud = utf8_fromcstr(value);
                if (ud != NULL && ud[0].width == 1)
                        w->fill_character = ud;
                else
                        free(ud);
        }
}

void
window_pane_default_cursor(struct window_pane *wp)
{
        screen_set_default_cursor(wp->screen, wp->options);
}

int
window_pane_mode(struct window_pane *wp)
{
        if (TAILQ_FIRST(&wp->modes) != NULL) {
                if (TAILQ_FIRST(&wp->modes)->mode == &window_copy_mode)
                        return (WINDOW_PANE_COPY_MODE);
                if (TAILQ_FIRST(&wp->modes)->mode == &window_view_mode)
                        return (WINDOW_PANE_VIEW_MODE);
        }
        return (WINDOW_PANE_NO_MODE);
}

/* Return 1 if scrollbar is or should be displayed. */
int
window_pane_show_scrollbar(struct window_pane *wp, int sb_option)
{
        if (SCREEN_IS_ALTERNATE(&wp->base))
                return (0);
        if (sb_option == PANE_SCROLLBARS_ALWAYS ||
            (sb_option == PANE_SCROLLBARS_MODAL &&
            window_pane_mode(wp) != WINDOW_PANE_NO_MODE))
                return (1);
        return (0);
}

int
window_pane_get_bg(struct window_pane *wp)
{
        int                     c;
        struct grid_cell        defaults;

        c = window_pane_get_bg_control_client(wp);
        if (c == -1) {
                tty_default_colours(&defaults, wp);
                if (COLOUR_DEFAULT(defaults.bg))
                        c = window_get_bg_client(wp);
                else
                        c = defaults.bg;
        }
        return (c);
}

/* Get a client with a background for the pane. */
int
window_get_bg_client(struct window_pane *wp)
{
        struct window   *w = wp->window;
        struct client   *loop;

        TAILQ_FOREACH(loop, &clients, entry) {
                if (loop->flags & CLIENT_UNATTACHEDFLAGS)
                        continue;
                if (loop->session == NULL || !session_has(loop->session, w))
                        continue;
                if (loop->tty.bg == -1)
                        continue;
                return (loop->tty.bg);
        }
        return (-1);
}

/*
 * If any control mode client exists that has provided a bg color, return it.
 * Otherwise, return -1.
 */
int
window_pane_get_bg_control_client(struct window_pane *wp)
{
        struct client   *c;

        if (wp->control_bg == -1)
                return (-1);

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->flags & CLIENT_CONTROL)
                        return (wp->control_bg);
        }
        return (-1);
}

/*
 * Get a client with a foreground for the pane. There isn't much to choose
 * between them so just use the first.
 */
int
window_pane_get_fg(struct window_pane *wp)
{
        struct window   *w = wp->window;
        struct client   *loop;

        TAILQ_FOREACH(loop, &clients, entry) {
                if (loop->flags & CLIENT_UNATTACHEDFLAGS)
                        continue;
                if (loop->session == NULL || !session_has(loop->session, w))
                        continue;
                if (loop->tty.fg == -1)
                        continue;
                return (loop->tty.fg);
        }
        return (-1);
}

/*
 * If any control mode client exists that has provided a fg color, return it.
 * Otherwise, return -1.
 */
int
window_pane_get_fg_control_client(struct window_pane *wp)
{
        struct client   *c;

        if (wp->control_fg == -1)
                return (-1);

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->flags & CLIENT_CONTROL)
                        return (wp->control_fg);
        }
        return (-1);
}

enum client_theme
window_pane_get_theme(struct window_pane *wp)
{
        struct window           *w;
        struct client           *loop;
        enum client_theme        theme;
        int                      found_light = 0, found_dark = 0;

        if (wp == NULL)
                return (THEME_UNKNOWN);
        w = wp->window;

        /*
         * Derive theme from pane background color, if it's not the default
         * colour.
         */
        theme = colour_totheme(window_pane_get_bg(wp));
        if (theme != THEME_UNKNOWN)
                return (theme);

        /* Try to find a client that has a theme. */
        TAILQ_FOREACH(loop, &clients, entry) {
                if (loop->flags & CLIENT_UNATTACHEDFLAGS)
                        continue;
                if (loop->session == NULL || !session_has(loop->session, w))
                        continue;
                switch (loop->theme) {
                case THEME_LIGHT:
                        found_light = 1;
                        break;
                case THEME_DARK:
                        found_dark = 1;
                        break;
                case THEME_UNKNOWN:
                        break;
                }
        }

        if (found_dark && !found_light)
                return (THEME_DARK);
        if (found_light && !found_dark)
                return (THEME_LIGHT);
        return (THEME_UNKNOWN);
}

void
window_pane_send_theme_update(struct window_pane *wp)
{
        enum client_theme       theme;

        if (wp == NULL || window_pane_exited(wp))
                return;
        if (~wp->flags & PANE_THEMECHANGED)
                return;
        if (~wp->screen->mode & MODE_THEME_UPDATES)
                return;

        theme = window_pane_get_theme(wp);
        if (theme == wp->last_theme)
                return;
        wp->last_theme = theme;
        wp->flags &= ~PANE_THEMECHANGED;

        switch (theme) {
        case THEME_LIGHT:
                log_debug("%s: %%%u light theme", __func__, wp->id);
                bufferevent_write(wp->event, "\033[?997;2n", 9);
                break;
        case THEME_DARK:
                log_debug("%s: %%%u dark theme", __func__, wp->id);
                bufferevent_write(wp->event, "\033[?997;1n", 9);
                break;
        case THEME_UNKNOWN:
                log_debug("%s: %%%u unknown theme", __func__, wp->id);
                break;
        }
}

struct style_range *
window_pane_border_status_get_range(struct window_pane *wp, u_int x, u_int y)
{
        struct style_ranges     *srs;
        struct window           *w = wp->window;
        struct options          *wo = w->options;
        u_int                    line;
        int                      pane_status;

        if (wp == NULL)
                return (NULL);
        srs = &wp->border_status_line.ranges;

        pane_status = options_get_number(wo, "pane-border-status");
        if (pane_status == PANE_STATUS_TOP)
                line = wp->yoff - 1;
        else if (pane_status == PANE_STATUS_BOTTOM)
                line = wp->yoff + wp->sy;
        if (pane_status == PANE_STATUS_OFF || line != y)
                return (NULL);

        /*
         * The border formats start 2 off but that isn't reflected in
         * the stored bounds of the range.
         */
        return (style_ranges_get_range(srs, x - wp->xoff - 2));
}