root/usr.bin/tmux/window-border.c
/* $OpenBSD: window-border.c,v 1.3 2026/07/23 09:38:27 nicm Exp $ */

/*
 * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

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

#include "tmux.h"

/* Set window fill cell. */
static void
window_set_fill_cell(struct window *w, int inside, struct grid_cell *gc)
{
        struct format_tree      *ft;
        struct screen            s;
        struct screen_write_ctx  ctx;
        struct grid_cell         new_gc;
        const char              *value;
        char                    *expanded;

        memcpy(gc, &grid_default_cell, sizeof *gc);
        gc->attr |= GRID_ATTR_CHARSET;
        utf8_set(&gc->data, CELL_BORDERS[CELL_NONE]);

        ft = format_create(NULL, NULL, FORMAT_WINDOW|w->id, FORMAT_NOJOBS);
        format_defaults(ft, NULL, NULL, NULL, w->active);
        format_add(ft, "is_inside", "%d", inside);
        format_add(ft, "is_outside", "%d", !inside);

        value = options_get_string(w->options, "fill-character");
        expanded = format_expand(ft, value);
        format_free(ft);

        screen_init(&s, 1, 1, 0);
        screen_write_start(&ctx, &s);
        format_draw(&ctx, &grid_default_cell, 1, expanded, NULL, 0);
        screen_write_stop(&ctx);
        free(expanded);

        grid_view_get_cell(s.grid, 0, 0, &new_gc);
        if (new_gc.data.width == 1)
                memcpy(gc, &new_gc, sizeof *gc);
        screen_free(&s);
}

/* Set window fill cells. */
void
window_set_fill_cells(struct window *w)
{
        window_set_fill_cell(w, 1, &w->inside_cell);
        window_set_fill_cell(w, 0, &w->outside_cell);
}

/* Merge a window fill cell over an existing style. */
static void
window_copy_fill_cell(struct grid_cell *gc, const struct grid_cell *fill)
{
        utf8_copy(&gc->data, &fill->data);
        gc->attr |= fill->attr;
        gc->flags |= fill->flags;
        if (fill->fg != 8)
                gc->fg = fill->fg;
        if (fill->bg != 8)
                gc->bg = fill->bg;
        if (fill->us != 8)
                gc->us = fill->us;
}

/* Get window fill cell. */
void
window_get_fill_cell(struct window *w, int inside, struct grid_cell *gc)
{
        if (inside)
                window_copy_fill_cell(gc, &w->inside_cell);
        else
                window_copy_fill_cell(gc, &w->outside_cell);
}

/* Get border cell. */
void
window_get_border_cell(struct window_pane *wp, enum pane_lines pane_lines,
    int cell_type, struct grid_cell *gc)
{
        u_int   idx;

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

/* Get pane border cell. */
void
window_pane_get_border_cell(struct window_pane *wp, int cell_type,
    struct grid_cell *gc)
{
        enum pane_lines pane_lines = window_pane_get_pane_lines(wp);

        window_get_border_cell(wp, pane_lines, cell_type, gc);
}

/* Get pane border style. */
void
window_pane_get_border_style(struct window_pane *wp, struct client *c,
    struct grid_cell *gc)
{
        struct session          *s = c->session;
        struct format_tree      *ft;
        const char              *option;
        struct grid_cell        *saved;
        int                     *flag;

        if (wp == c->session->curw->window->active) {
                flag = &wp->active_border_gc_set;
                saved = &wp->active_border_gc;
                option = "pane-active-border-style";
        } else {
                flag = &wp->border_gc_set;
                saved = &wp->border_gc;
                option = "pane-border-style";
        }

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

/* Build pane status line. */
int
window_make_pane_status(struct window_pane *wp, struct client *c, u_int width,
    struct redraw_span *span)
{
        struct grid_cell         gc;
        const char              *fmt;
        struct format_tree      *ft;
        struct style_line_entry *sle = &wp->border_status_line;
        struct screen_write_ctx  ctx;
        struct screen            old;
        char                    *expanded;
        u_int                    i;
        enum pane_lines          pane_lines;
        int                      pane_status, cell_type;

        pane_status = window_pane_get_pane_status(wp);
        if (pane_status == PANE_STATUS_OFF || width == 0)
                return (0);

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

        fmt = options_get_string(wp->options, "pane-border-format");
        expanded = format_expand_time(ft, fmt);

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

        window_pane_get_border_style(wp, c, &gc);
        pane_lines = window_pane_get_pane_lines(wp);
        for (i = 0; i < width; i++) {
                cell_type = redraw_get_status_border_cell_type(&span, i);
                window_get_border_cell(wp, pane_lines, cell_type, &gc);
                screen_write_cell(&ctx, &gc);
        }
        gc.attr &= ~GRID_ATTR_CHARSET;

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

        screen_write_stop(&ctx);
        format_free(ft);

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

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