* Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>

/* $OpenBSD$ */

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

#include <sys/types.h>

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

#include "tmux.h"

static struct screen_write_citem *screen_write_collect_trim(
struct screen_write_ctx *, u_int, u_int, u_int, int *);
static void screen_write_collect_clear(struct screen_write_ctx *, u_int,
u_int);
static void screen_write_collect_scroll(struct screen_write_ctx *, u_int);
static void screen_write_collect_flush(struct screen_write_ctx *, int,
const char *);
static int screen_write_overwrite(struct screen_write_ctx *,
struct grid_cell *, u_int);
static int screen_write_combine(struct screen_write_ctx *,
const struct grid_cell *);

struct screen_write_citem {
u_int x;
int wrapped;

enum { TEXT, CLEAR } type;
u_int used;
u_int bg;

struct grid_cell gc;

TAILQ_ENTRY(screen_write_citem) entry;
};
struct screen_write_cline {
char *data;
TAILQ_HEAD(, screen_write_citem) items;
};
TAILQ_HEAD(, screen_write_citem) screen_write_citem_freelist =
TAILQ_HEAD_INITIALIZER(screen_write_citem_freelist);

static struct screen_write_citem *
screen_write_get_citem(void)
{
struct screen_write_citem *ci;

ci = TAILQ_FIRST(&screen_write_citem_freelist);
if (ci != NULL) {
TAILQ_REMOVE(&screen_write_citem_freelist, ci, entry);
memset(ci, 0, sizeof *ci);
return (ci);
}
return (xcalloc(1, sizeof *ci));
}

static void
screen_write_free_citem(struct screen_write_citem *ci)
{
TAILQ_INSERT_TAIL(&screen_write_citem_freelist, ci, entry);
}

static void
screen_write_offset_timer(__unused int fd, __unused short events, void *data)
{
struct window *w = data;

tty_update_window_offset(w);
}

/* Set cursor position. */
static void
screen_write_set_cursor(struct screen_write_ctx *ctx, int cx, int cy)
{
struct window_pane *wp = ctx->wp;
struct window *w;
struct screen *s = ctx->s;
struct timeval tv = { .tv_usec = 10000 };

if (cx != -1 && (u_int)cx == s->cx && cy != -1 && (u_int)cy == s->cy)
return;

if (cx != -1) {
if ((u_int)cx > screen_size_x(s)) /* allow last column */
cx = screen_size_x(s) - 1;
s->cx = cx;
}
if (cy != -1) {
if ((u_int)cy > screen_size_y(s) - 1)
cy = screen_size_y(s) - 1;
s->cy = cy;
}

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

if (!event_initialized(&w->offset_timer))
evtimer_set(&w->offset_timer, screen_write_offset_timer, w);
if (!evtimer_pending(&w->offset_timer, NULL))
evtimer_add(&w->offset_timer, &tv);
}

/* Do a full redraw. */
static void
screen_write_redraw_cb(const struct tty_ctx *ttyctx)
{
struct window_pane *wp = ttyctx->arg;

if (wp != NULL)
wp->flags |= PANE_REDRAW;
}

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

if (ttyctx->allow_invisible_panes) {
if (session_has(c->session, wp->window))
return (1);
return (0);
}

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

if (wp->flags & (PANE_REDRAW|PANE_DROP))
return (-1);
if (c->flags & CLIENT_REDRAWPANES) {
/*
* Redraw is already deferred to redraw another pane - redraw
* this one also when that happens.
*/
log_debug("%s: adding %%%u to deferred redraw", __func__,
wp->id);
wp->flags |= PANE_REDRAW;
return (-1);
}

ttyctx->bigger = tty_window_offset(&c->tty, &ttyctx->wox, &ttyctx->woy,
&ttyctx->wsx, &ttyctx->wsy);

ttyctx->xoff = ttyctx->rxoff = wp->xoff;
ttyctx->yoff = ttyctx->ryoff = wp->yoff;

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

return (1);
}

/* Set up context for TTY command. */
static void
screen_write_initctx(struct screen_write_ctx *ctx, struct tty_ctx *ttyctx,
int sync)
{
struct screen *s = ctx->s;

memset(ttyctx, 0, sizeof *ttyctx);

ttyctx->s = s;
ttyctx->sx = screen_size_x(s);
ttyctx->sy = screen_size_y(s);

ttyctx->ocx = s->cx;
ttyctx->ocy = s->cy;
ttyctx->orlower = s->rlower;
ttyctx->orupper = s->rupper;

memcpy(&ttyctx->defaults, &grid_default_cell, sizeof ttyctx->defaults);
if (ctx->init_ctx_cb != NULL) {
ctx->init_ctx_cb(ctx, ttyctx);
if (ttyctx->palette != NULL) {
if (ttyctx->defaults.fg == 8)
ttyctx->defaults.fg = ttyctx->palette->fg;
if (ttyctx->defaults.bg == 8)
ttyctx->defaults.bg = ttyctx->palette->bg;
}
} else {
ttyctx->redraw_cb = screen_write_redraw_cb;
if (ctx->wp != NULL) {
tty_default_colours(&ttyctx->defaults, ctx->wp);
ttyctx->palette = &ctx->wp->palette;
ttyctx->set_client_cb = screen_write_set_client_cb;
ttyctx->arg = ctx->wp;
}
}

if (~ctx->flags & SCREEN_WRITE_SYNC) {
/*
* For the active pane or for an overlay (no pane), we want to
* only use synchronized updates if requested (commands that
* move the cursor); for other panes, always use it, since the
* cursor will have to move.
*/
if (ctx->wp != NULL) {
if (ctx->wp != ctx->wp->window->active)
ttyctx->num = 1;
else
ttyctx->num = sync;
} else
ttyctx->num = 0x10|sync;
tty_write(tty_cmd_syncstart, ttyctx);
ctx->flags |= SCREEN_WRITE_SYNC;
}
}

/* Make write list. */
void
screen_write_make_list(struct screen *s)
{
u_int y;

s->write_list = xcalloc(screen_size_y(s), sizeof *s->write_list);
for (y = 0; y < screen_size_y(s); y++)
TAILQ_INIT(&s->write_list[y].items);
}

/* Free write list. */
void
screen_write_free_list(struct screen *s)
{
u_int y;

for (y = 0; y < screen_size_y(s); y++)
free(s->write_list[y].data);
free(s->write_list);
}

/* Set up for writing. */
static void
screen_write_init(struct screen_write_ctx *ctx, struct screen *s)
{
memset(ctx, 0, sizeof *ctx);

ctx->s = s;

if (ctx->s->write_list == NULL)
screen_write_make_list(ctx->s);
ctx->item = screen_write_get_citem();

ctx->scrolled = 0;
ctx->bg = 8;
}

/* Initialize writing with a pane. */
void
screen_write_start_pane(struct screen_write_ctx *ctx, struct window_pane *wp,
struct screen *s)
{
if (s == NULL)
s = wp->screen;
screen_write_init(ctx, s);
ctx->wp = wp;

if (log_get_level() != 0) {
log_debug("%s: size %ux%u, pane %%%u (at %u,%u)",
__func__, screen_size_x(ctx->s), screen_size_y(ctx->s),
wp->id, wp->xoff, wp->yoff);
}
}

/* Initialize writing with a callback. */
void
screen_write_start_callback(struct screen_write_ctx *ctx, struct screen *s,
screen_write_init_ctx_cb cb, void *arg)
{
screen_write_init(ctx, s);

ctx->init_ctx_cb = cb;
ctx->arg = arg;

if (log_get_level() != 0) {
log_debug("%s: size %ux%u, with callback", __func__,
screen_size_x(ctx->s), screen_size_y(ctx->s));
}
}

/* Initialize writing. */
void
screen_write_start(struct screen_write_ctx *ctx, struct screen *s)
{
screen_write_init(ctx, s);

if (log_get_level() != 0) {
log_debug("%s: size %ux%u, no pane", __func__,
screen_size_x(ctx->s), screen_size_y(ctx->s));
}
}

/* Finish writing. */
void
screen_write_stop(struct screen_write_ctx *ctx)
{
screen_write_collect_end(ctx);
screen_write_collect_flush(ctx, 0, __func__);

screen_write_free_citem(ctx->item);
}

/* Reset screen state. */
void
screen_write_reset(struct screen_write_ctx *ctx)
{
struct screen *s = ctx->s;

screen_reset_tabs(s);
screen_write_scrollregion(ctx, 0, screen_size_y(s) - 1);

s->mode = MODE_CURSOR|MODE_WRAP;

if (options_get_number(global_options, "extended-keys") == 2)
s->mode = (s->mode & ~EXTENDED_KEY_MODES)|MODE_KEYS_EXTENDED;

screen_write_clearscreen(ctx, 8);
screen_write_set_cursor(ctx, 0, 0);
}

/* Write character. */
void
screen_write_putc(struct screen_write_ctx *ctx, const struct grid_cell *gcp,
u_char ch)
{
struct grid_cell gc;

memcpy(&gc, gcp, sizeof gc);

utf8_set(&gc.data, ch);
screen_write_cell(ctx, &gc);
}

/* Calculate string length. */
size_t
screen_write_strlen(const char *fmt, ...)
{
va_list ap;
char *msg;
struct utf8_data ud;
u_char *ptr;
size_t left, size = 0;
enum utf8_state more;

va_start(ap, fmt);
xvasprintf(&msg, fmt, ap);
va_end(ap);

ptr = (u_char *)msg;
while (*ptr != '\0') {
if (*ptr > 0x7f && utf8_open(&ud, *ptr) == UTF8_MORE) {
ptr++;

left = strlen((char *)ptr);
if (left < (size_t)ud.size - 1)
break;
while ((more = utf8_append(&ud, *ptr)) == UTF8_MORE)
ptr++;
ptr++;

if (more == UTF8_DONE)
size += ud.width;
} else {
if (*ptr > 0x1f && *ptr < 0x7f)
size++;
ptr++;
}
}

free(msg);
return (size);
}

/* Write string wrapped over lines. */
int
screen_write_text(struct screen_write_ctx *ctx, u_int cx, u_int width,
u_int lines, int more, const struct grid_cell *gcp, const char *fmt, ...)
{
struct screen *s = ctx->s;
va_list ap;
char *tmp;
u_int cy = s->cy, i, end, next, idx = 0, at, left;
struct utf8_data *text;
struct grid_cell gc;

memcpy(&gc, gcp, sizeof gc);

va_start(ap, fmt);
xvasprintf(&tmp, fmt, ap);
va_end(ap);

text = utf8_fromcstr(tmp);
free(tmp);

left = (cx + width) - s->cx;
for (;;) {
/* Find the end of what can fit on the line. */
at = 0;
for (end = idx; text[end].size != 0; end++) {
if (text[end].size == 1 && text[end].data[0] == '\n')
break;
if (at + text[end].width > left)
break;
at += text[end].width;
}

/*
* If we're on a space, that's the end. If not, walk back to
* try and find one.
*/
if (text[end].size == 0)
next = end;
else if (text[end].size == 1 && text[end].data[0] == '\n')
next = end + 1;
else if (text[end].size == 1 && text[end].data[0] == ' ')
next = end + 1;
else {
for (i = end; i > idx; i--) {
if (text[i].size == 1 && text[i].data[0] == ' ')
break;
}
if (i != idx) {
next = i + 1;
end = i;
} else
next = end;
}

/* Print the line. */
for (i = idx; i < end; i++) {
utf8_copy(&gc.data, &text[i]);
screen_write_cell(ctx, &gc);
}

/* If at the bottom, stop. */
idx = next;
if (s->cy == cy + lines - 1 || text[idx].size == 0)
break;

screen_write_cursormove(ctx, cx, s->cy + 1, 0);
left = width;
}

/*
* Fail if on the last line and there is more to come or at the end, or
* if the text was not entirely consumed.
*/
if ((s->cy == cy + lines - 1 && (!more || s->cx == cx + width)) ||
text[idx].size != 0) {
free(text);
return (0);
}
free(text);

/*
* If no more to come, move to the next line. Otherwise, leave on
* the same line (except if at the end).
*/
if (!more || s->cx == cx + width)
screen_write_cursormove(ctx, cx, s->cy + 1, 0);
return (1);
}

/* Write simple string (no maximum length). */
void
screen_write_puts(struct screen_write_ctx *ctx, const struct grid_cell *gcp,
const char *fmt, ...)
{
va_list ap;

va_start(ap, fmt);
screen_write_vnputs(ctx, -1, gcp, fmt, ap);
va_end(ap);
}

/* Write string with length limit (-1 for unlimited). */
void
screen_write_nputs(struct screen_write_ctx *ctx, ssize_t maxlen,
const struct grid_cell *gcp, const char *fmt, ...)
{
va_list ap;

va_start(ap, fmt);
screen_write_vnputs(ctx, maxlen, gcp, fmt, ap);
va_end(ap);
}

void
screen_write_vnputs(struct screen_write_ctx *ctx, ssize_t maxlen,
const struct grid_cell *gcp, const char *fmt, va_list ap)
{
struct grid_cell gc;
struct utf8_data *ud = &gc.data;
char *msg;
u_char *ptr;
size_t left, size = 0;
enum utf8_state more;

memcpy(&gc, gcp, sizeof gc);
xvasprintf(&msg, fmt, ap);

ptr = (u_char *)msg;
while (*ptr != '\0') {
if (*ptr > 0x7f && utf8_open(ud, *ptr) == UTF8_MORE) {
ptr++;

left = strlen((char *)ptr);
if (left < (size_t)ud->size - 1)
break;
while ((more = utf8_append(ud, *ptr)) == UTF8_MORE)
ptr++;
ptr++;

if (more != UTF8_DONE)
continue;
if (maxlen > 0 && size + ud->width > (size_t)maxlen) {
while (size < (size_t)maxlen) {
screen_write_putc(ctx, &gc, ' ');
size++;
}
break;
}
size += ud->width;
screen_write_cell(ctx, &gc);
} else {
if (maxlen > 0 && size + 1 > (size_t)maxlen)
break;

if (*ptr == '\001')
gc.attr ^= GRID_ATTR_CHARSET;
else if (*ptr == '\n') {
screen_write_linefeed(ctx, 0, 8);
screen_write_carriagereturn(ctx);
} else if (*ptr > 0x1f && *ptr < 0x7f) {
size++;
screen_write_putc(ctx, &gc, *ptr);
}
ptr++;
}
}

free(msg);
}

/*
* Copy from another screen but without the selection stuff. Assumes the target
* region is already big enough.
*/
void
screen_write_fast_copy(struct screen_write_ctx *ctx, struct screen *src,
u_int px, u_int py, u_int nx, u_int ny)
{
struct screen *s = ctx->s;
struct grid *gd = src->grid;
struct grid_cell gc;
u_int xx, yy, cx, cy;

if (nx == 0 || ny == 0)
return;

cy = s->cy;
for (yy = py; yy < py + ny; yy++) {
if (yy >= gd->hsize + gd->sy)
break;
cx = s->cx;
for (xx = px; xx < px + nx; xx++) {
if (xx >= grid_get_line(gd, yy)->cellsize)
break;
grid_get_cell(gd, xx, yy, &gc);
if (xx + gc.data.width > px + nx)
break;
grid_view_set_cell(ctx->s->grid, cx, cy, &gc);
cx++;
}
cy++;
}
}

/* Select character set for drawing border lines. */
static void
screen_write_box_border_set(enum box_lines lines, int cell_type,
struct grid_cell *gc)
{
switch (lines) {
case BOX_LINES_NONE:
break;
case BOX_LINES_DOUBLE:
gc->attr &= ~GRID_ATTR_CHARSET;
utf8_copy(&gc->data, tty_acs_double_borders(cell_type));
break;
case BOX_LINES_HEAVY:
gc->attr &= ~GRID_ATTR_CHARSET;
utf8_copy(&gc->data, tty_acs_heavy_borders(cell_type));
break;
case BOX_LINES_ROUNDED:
gc->attr &= ~GRID_ATTR_CHARSET;
utf8_copy(&gc->data, tty_acs_rounded_borders(cell_type));
break;
case BOX_LINES_SIMPLE:
gc->attr &= ~GRID_ATTR_CHARSET;
utf8_set(&gc->data, SIMPLE_BORDERS[cell_type]);
break;
case BOX_LINES_PADDED:
gc->attr &= ~GRID_ATTR_CHARSET;
utf8_set(&gc->data, PADDED_BORDERS[cell_type]);
break;
case BOX_LINES_SINGLE:
case BOX_LINES_DEFAULT:
gc->attr |= GRID_ATTR_CHARSET;
utf8_set(&gc->data, CELL_BORDERS[cell_type]);
break;
}
}

/* Draw a horizontal line on screen. */
void
screen_write_hline(struct screen_write_ctx *ctx, u_int nx, int left, int right,
enum box_lines lines, const struct grid_cell *border_gc)
{
struct screen *s = ctx->s;
struct grid_cell gc;
u_int cx, cy, i;

cx = s->cx;
cy = s->cy;

if (border_gc != NULL)
memcpy(&gc, border_gc, sizeof gc);
else
memcpy(&gc, &grid_default_cell, sizeof gc);
gc.attr |= GRID_ATTR_CHARSET;

if (left)
screen_write_box_border_set(lines, CELL_LEFTJOIN, &gc);
else
screen_write_box_border_set(lines, CELL_LEFTRIGHT, &gc);
screen_write_cell(ctx, &gc);

screen_write_box_border_set(lines, CELL_LEFTRIGHT, &gc);
for (i = 1; i < nx - 1; i++)
screen_write_cell(ctx, &gc);

if (right)
screen_write_box_border_set(lines, CELL_RIGHTJOIN, &gc);
else
screen_write_box_border_set(lines, CELL_LEFTRIGHT, &gc);
screen_write_cell(ctx, &gc);

screen_write_set_cursor(ctx, cx, cy);
}

/* Draw a vertical line on screen. */
void
screen_write_vline(struct screen_write_ctx *ctx, u_int ny, int top, int bottom)
{
struct screen *s = ctx->s;
struct grid_cell gc;
u_int cx, cy, i;

cx = s->cx;
cy = s->cy;

memcpy(&gc, &grid_default_cell, sizeof gc);
gc.attr |= GRID_ATTR_CHARSET;

screen_write_putc(ctx, &gc, top ? 'w' : 'x');
for (i = 1; i < ny - 1; i++) {
screen_write_set_cursor(ctx, cx, cy + i);
screen_write_putc(ctx, &gc, 'x');
}
screen_write_set_cursor(ctx, cx, cy + ny - 1);
screen_write_putc(ctx, &gc, bottom ? 'v' : 'x');

screen_write_set_cursor(ctx, cx, cy);
}

/* Draw a menu on screen. */
void
screen_write_menu(struct screen_write_ctx *ctx, struct menu *menu, int choice,
enum box_lines lines, const struct grid_cell *menu_gc,
const struct grid_cell *border_gc, const struct grid_cell *choice_gc)
{
struct screen *s = ctx->s;
struct grid_cell default_gc;
const struct grid_cell *gc = &default_gc;
u_int cx, cy, i, j, width = menu->width;
const char *name;

cx = s->cx;
cy = s->cy;

memcpy(&default_gc, menu_gc, sizeof default_gc);

screen_write_box(ctx, menu->width + 4, menu->count + 2, lines,
border_gc, menu->title);

for (i = 0; i < menu->count; i++) {
name = menu->items[i].name;
if (name == NULL) {
screen_write_cursormove(ctx, cx, cy + 1 + i, 0);
screen_write_hline(ctx, width + 4, 1, 1, lines,
border_gc);
continue;
}

if (choice >= 0 && i == (u_int)choice && *name != '-')
gc = choice_gc;

screen_write_cursormove(ctx, cx + 1, cy + 1 + i, 0);
for (j = 0; j < width + 2; j++)
screen_write_putc(ctx, gc, ' ');

screen_write_cursormove(ctx, cx + 2, cy + 1 + i, 0);
if (*name == '-') {
default_gc.attr |= GRID_ATTR_DIM;
format_draw(ctx, gc, width, name + 1, NULL, 0);
default_gc.attr &= ~GRID_ATTR_DIM;
continue;
}

format_draw(ctx, gc, width, name, NULL, 0);
gc = &default_gc;
}

screen_write_set_cursor(ctx, cx, cy);
}

/* Draw a box on screen. */
void
screen_write_box(struct screen_write_ctx *ctx, u_int nx, u_int ny,
enum box_lines lines, const struct grid_cell *gcp, const char *title)
{
struct screen *s = ctx->s;
struct grid_cell gc;
u_int cx, cy, i;

cx = s->cx;
cy = s->cy;

if (gcp != NULL)
memcpy(&gc, gcp, sizeof gc);
else
memcpy(&gc, &grid_default_cell, sizeof gc);

gc.attr |= GRID_ATTR_CHARSET;
gc.flags |= GRID_FLAG_NOPALETTE;

/* Draw top border */
screen_write_box_border_set(lines, CELL_TOPLEFT, &gc);
screen_write_cell(ctx, &gc);
screen_write_box_border_set(lines, CELL_LEFTRIGHT, &gc);
for (i = 1; i < nx - 1; i++)
screen_write_cell(ctx, &gc);
screen_write_box_border_set(lines, CELL_TOPRIGHT, &gc);
screen_write_cell(ctx, &gc);

/* Draw bottom border */
screen_write_set_cursor(ctx, cx, cy + ny - 1);
screen_write_box_border_set(lines, CELL_BOTTOMLEFT, &gc);
screen_write_cell(ctx, &gc);
screen_write_box_border_set(lines, CELL_LEFTRIGHT, &gc);
for (i = 1; i < nx - 1; i++)
screen_write_cell(ctx, &gc);
screen_write_box_border_set(lines, CELL_BOTTOMRIGHT, &gc);
screen_write_cell(ctx, &gc);

/* Draw sides */
screen_write_box_border_set(lines, CELL_TOPBOTTOM, &gc);
for (i = 1; i < ny - 1; i++) {
/* left side */
screen_write_set_cursor(ctx, cx, cy + i);
screen_write_cell(ctx, &gc);
/* right side */
screen_write_set_cursor(ctx, cx + nx - 1, cy + i);
screen_write_cell(ctx, &gc);
}

if (title != NULL) {
gc.attr &= ~GRID_ATTR_CHARSET;
screen_write_cursormove(ctx, cx + 2, cy, 0);
format_draw(ctx, &gc, nx - 4, title, NULL, 0);
}

screen_write_set_cursor(ctx, cx, cy);
}

/*
* Write a preview version of a window. Assumes target area is big enough and
* already cleared.
*/
void
screen_write_preview(struct screen_write_ctx *ctx, struct screen *src, u_int nx,
u_int ny)
{
struct screen *s = ctx->s;
struct grid_cell gc;
u_int cx, cy, px, py;

cx = s->cx;
cy = s->cy;

/*
* If the cursor is on, pick the area around the cursor, otherwise use
* the top left.
*/
if (src->mode & MODE_CURSOR) {
px = src->cx;
if (px < nx / 3)
px = 0;
else
px = px - nx / 3;
if (px + nx > screen_size_x(src)) {
if (nx > screen_size_x(src))
px = 0;
else
px = screen_size_x(src) - nx;
}
py = src->cy;
if (py < ny / 3)
py = 0;
else
py = py - ny / 3;
if (py + ny > screen_size_y(src)) {
if (ny > screen_size_y(src))
py = 0;
else
py = screen_size_y(src) - ny;
}
} else {
px = 0;
py = 0;
}

screen_write_fast_copy(ctx, src, px, src->grid->hsize + py, nx, ny);

if (src->mode & MODE_CURSOR) {
grid_view_get_cell(src->grid, src->cx, src->cy, &gc);
gc.attr |= GRID_ATTR_REVERSE;
screen_write_set_cursor(ctx, cx + (src->cx - px),
cy + (src->cy - py));
screen_write_cell(ctx, &gc);
}
}

/* Set a mode. */
void
screen_write_mode_set(struct screen_write_ctx *ctx, int mode)
{
struct screen *s = ctx->s;

s->mode |= mode;

if (log_get_level() != 0)
log_debug("%s: %s", __func__, screen_mode_to_string(mode));
}

/* Clear a mode. */
void
screen_write_mode_clear(struct screen_write_ctx *ctx, int mode)
{
struct screen *s = ctx->s;

s->mode &= ~mode;

if (log_get_level() != 0)
log_debug("%s: %s", __func__, screen_mode_to_string(mode));
}

/* Cursor up by ny. */
void
screen_write_cursorup(struct screen_write_ctx *ctx, u_int ny)
{
struct screen *s = ctx->s;
u_int cx = s->cx, cy = s->cy;

if (ny == 0)
ny = 1;

if (cy < s->rupper) {
/* Above region. */
if (ny > cy)
ny = cy;
} else {
/* Below region. */
if (ny > cy - s->rupper)
ny = cy - s->rupper;
}
if (cx == screen_size_x(s))
cx--;

cy -= ny;

screen_write_set_cursor(ctx, cx, cy);
}

/* Cursor down by ny. */
void
screen_write_cursordown(struct screen_write_ctx *ctx, u_int ny)
{
struct screen *s = ctx->s;
u_int cx = s->cx, cy = s->cy;

if (ny == 0)
ny = 1;

if (cy > s->rlower) {
/* Below region. */
if (ny > screen_size_y(s) - 1 - cy)
ny = screen_size_y(s) - 1 - cy;
} else {
/* Above region. */
if (ny > s->rlower - cy)
ny = s->rlower - cy;
}
if (cx == screen_size_x(s))
cx--;
else if (ny == 0)
return;

cy += ny;

screen_write_set_cursor(ctx, cx, cy);
}

/* Cursor right by nx. */
void
screen_write_cursorright(struct screen_write_ctx *ctx, u_int nx)
{
struct screen *s = ctx->s;
u_int cx = s->cx, cy = s->cy;

if (nx == 0)
nx = 1;

if (nx > screen_size_x(s) - 1 - cx)
nx = screen_size_x(s) - 1 - cx;
if (nx == 0)
return;

cx += nx;

screen_write_set_cursor(ctx, cx, cy);
}

/* Cursor left by nx. */
void
screen_write_cursorleft(struct screen_write_ctx *ctx, u_int nx)
{
struct screen *s = ctx->s;
u_int cx = s->cx, cy = s->cy;

if (nx == 0)
nx = 1;

if (nx > cx)
nx = cx;
if (nx == 0)
return;

cx -= nx;

screen_write_set_cursor(ctx, cx, cy);
}

/* Backspace; cursor left unless at start of wrapped line when can move up. */
void
screen_write_backspace(struct screen_write_ctx *ctx)
{
struct screen *s = ctx->s;
struct grid_line *gl;
u_int cx = s->cx, cy = s->cy;

if (cx == 0) {
if (cy == 0)
return;
gl = grid_get_line(s->grid, s->grid->hsize + cy - 1);
if (gl->flags & GRID_LINE_WRAPPED) {
cy--;
cx = screen_size_x(s) - 1;
}
} else
cx--;

screen_write_set_cursor(ctx, cx, cy);
}

/* VT100 alignment test. */
void
screen_write_alignmenttest(struct screen_write_ctx *ctx)
{
struct screen *s = ctx->s;
struct tty_ctx ttyctx;
struct grid_cell gc;
u_int xx, yy;

memcpy(&gc, &grid_default_cell, sizeof gc);
utf8_set(&gc.data, 'E');

#ifdef ENABLE_SIXEL
if (image_free_all(s) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

for (yy = 0; yy < screen_size_y(s); yy++) {
for (xx = 0; xx < screen_size_x(s); xx++)
grid_view_set_cell(s->grid, xx, yy, &gc);
}

screen_write_set_cursor(ctx, 0, 0);

s->rupper = 0;
s->rlower = screen_size_y(s) - 1;

screen_write_initctx(ctx, &ttyctx, 1);

screen_write_collect_clear(ctx, 0, screen_size_y(s) - 1);
tty_write(tty_cmd_alignmenttest, &ttyctx);
}

/* Insert nx characters. */
void
screen_write_insertcharacter(struct screen_write_ctx *ctx, u_int nx, u_int bg)
{
struct screen *s = ctx->s;
struct tty_ctx ttyctx;

if (nx == 0)
nx = 1;

if (nx > screen_size_x(s) - s->cx)
nx = screen_size_x(s) - s->cx;
if (nx == 0)
return;

if (s->cx > screen_size_x(s) - 1)
return;

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, 1) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

screen_write_initctx(ctx, &ttyctx, 0);
ttyctx.bg = bg;

grid_view_insert_cells(s->grid, s->cx, s->cy, nx, bg);

screen_write_collect_flush(ctx, 0, __func__);
ttyctx.num = nx;
tty_write(tty_cmd_insertcharacter, &ttyctx);
}

/* Delete nx characters. */
void
screen_write_deletecharacter(struct screen_write_ctx *ctx, u_int nx, u_int bg)
{
struct screen *s = ctx->s;
struct tty_ctx ttyctx;

if (nx == 0)
nx = 1;

if (nx > screen_size_x(s) - s->cx)
nx = screen_size_x(s) - s->cx;
if (nx == 0)
return;

if (s->cx > screen_size_x(s) - 1)
return;

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, 1) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

screen_write_initctx(ctx, &ttyctx, 0);
ttyctx.bg = bg;

grid_view_delete_cells(s->grid, s->cx, s->cy, nx, bg);

screen_write_collect_flush(ctx, 0, __func__);
ttyctx.num = nx;
tty_write(tty_cmd_deletecharacter, &ttyctx);
}

/* Clear nx characters. */
void
screen_write_clearcharacter(struct screen_write_ctx *ctx, u_int nx, u_int bg)
{
struct screen *s = ctx->s;
struct tty_ctx ttyctx;

if (nx == 0)
nx = 1;

if (nx > screen_size_x(s) - s->cx)
nx = screen_size_x(s) - s->cx;
if (nx == 0)
return;

if (s->cx > screen_size_x(s) - 1)
return;

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, 1) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

screen_write_initctx(ctx, &ttyctx, 0);
ttyctx.bg = bg;

grid_view_clear(s->grid, s->cx, s->cy, nx, 1, bg);

screen_write_collect_flush(ctx, 0, __func__);
ttyctx.num = nx;
tty_write(tty_cmd_clearcharacter, &ttyctx);
}

/* Insert ny lines. */
void
screen_write_insertline(struct screen_write_ctx *ctx, u_int ny, u_int bg)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
struct tty_ctx ttyctx;

#ifdef ENABLE_SIXEL
u_int sy = screen_size_y(s);
#endif

if (ny == 0)
ny = 1;

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, sy - s->cy) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

if (s->cy < s->rupper || s->cy > s->rlower) {
if (ny > screen_size_y(s) - s->cy)
ny = screen_size_y(s) - s->cy;
if (ny == 0)
return;

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

grid_view_insert_lines(gd, s->cy, ny, bg);

screen_write_collect_flush(ctx, 0, __func__);
ttyctx.num = ny;
tty_write(tty_cmd_insertline, &ttyctx);
return;
}

if (ny > s->rlower + 1 - s->cy)
ny = s->rlower + 1 - s->cy;
if (ny == 0)
return;

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

if (s->cy < s->rupper || s->cy > s->rlower)
grid_view_insert_lines(gd, s->cy, ny, bg);
else
grid_view_insert_lines_region(gd, s->rlower, s->cy, ny, bg);

screen_write_collect_flush(ctx, 0, __func__);

ttyctx.num = ny;
tty_write(tty_cmd_insertline, &ttyctx);
}

/* Delete ny lines. */
void
screen_write_deleteline(struct screen_write_ctx *ctx, u_int ny, u_int bg)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
struct tty_ctx ttyctx;
u_int sy = screen_size_y(s);

if (ny == 0)
ny = 1;

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, sy - s->cy) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

if (s->cy < s->rupper || s->cy > s->rlower) {
if (ny > sy - s->cy)
ny = sy - s->cy;
if (ny == 0)
return;

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

grid_view_delete_lines(gd, s->cy, ny, bg);

screen_write_collect_flush(ctx, 0, __func__);
ttyctx.num = ny;
tty_write(tty_cmd_deleteline, &ttyctx);
return;
}

if (ny > s->rlower + 1 - s->cy)
ny = s->rlower + 1 - s->cy;
if (ny == 0)
return;

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

if (s->cy < s->rupper || s->cy > s->rlower)
grid_view_delete_lines(gd, s->cy, ny, bg);
else
grid_view_delete_lines_region(gd, s->rlower, s->cy, ny, bg);

screen_write_collect_flush(ctx, 0, __func__);
ttyctx.num = ny;
tty_write(tty_cmd_deleteline, &ttyctx);
}

/* Clear line at cursor. */
void
screen_write_clearline(struct screen_write_ctx *ctx, u_int bg)
{
struct screen *s = ctx->s;
struct grid_line *gl;
u_int sx = screen_size_x(s);
struct screen_write_citem *ci = ctx->item;

gl = grid_get_line(s->grid, s->grid->hsize + s->cy);
if (gl->cellsize == 0 && COLOUR_DEFAULT(bg))
return;

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, 1) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

grid_view_clear(s->grid, 0, s->cy, sx, 1, bg);

screen_write_collect_clear(ctx, s->cy, 1);
ci->x = 0;
ci->used = sx;
ci->type = CLEAR;
ci->bg = bg;
TAILQ_INSERT_TAIL(&ctx->s->write_list[s->cy].items, ci, entry);
ctx->item = screen_write_get_citem();
}

/* Clear to end of line from cursor. */
void
screen_write_clearendofline(struct screen_write_ctx *ctx, u_int bg)
{
struct screen *s = ctx->s;
struct grid_line *gl;
u_int sx = screen_size_x(s);
struct screen_write_citem *ci = ctx->item, *before;

if (s->cx == 0) {
screen_write_clearline(ctx, bg);
return;
}

gl = grid_get_line(s->grid, s->grid->hsize + s->cy);
if (s->cx > sx - 1 || (s->cx >= gl->cellsize && COLOUR_DEFAULT(bg)))
return;

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, 1) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

grid_view_clear(s->grid, s->cx, s->cy, sx - s->cx, 1, bg);

before = screen_write_collect_trim(ctx, s->cy, s->cx, sx - s->cx, NULL);
ci->x = s->cx;
ci->used = sx - s->cx;
ci->type = CLEAR;
ci->bg = bg;
if (before == NULL)
TAILQ_INSERT_TAIL(&ctx->s->write_list[s->cy].items, ci, entry);
else
TAILQ_INSERT_BEFORE(before, ci, entry);
ctx->item = screen_write_get_citem();
}

/* Clear to start of line from cursor. */
void
screen_write_clearstartofline(struct screen_write_ctx *ctx, u_int bg)
{
struct screen *s = ctx->s;
u_int sx = screen_size_x(s);
struct screen_write_citem *ci = ctx->item, *before;

if (s->cx >= sx - 1) {
screen_write_clearline(ctx, bg);
return;
}

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, 1) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

if (s->cx > sx - 1)
grid_view_clear(s->grid, 0, s->cy, sx, 1, bg);
else
grid_view_clear(s->grid, 0, s->cy, s->cx + 1, 1, bg);

before = screen_write_collect_trim(ctx, s->cy, 0, s->cx + 1, NULL);
ci->x = 0;
ci->used = s->cx + 1;
ci->type = CLEAR;
ci->bg = bg;
if (before == NULL)
TAILQ_INSERT_TAIL(&ctx->s->write_list[s->cy].items, ci, entry);
else
TAILQ_INSERT_BEFORE(before, ci, entry);
ctx->item = screen_write_get_citem();
}

/* Move cursor to px,py. */
void
screen_write_cursormove(struct screen_write_ctx *ctx, int px, int py,
int origin)
{
struct screen *s = ctx->s;

if (origin && py != -1 && (s->mode & MODE_ORIGIN)) {
if ((u_int)py > s->rlower - s->rupper)
py = s->rlower;
else
py += s->rupper;
}

if (px != -1 && (u_int)px > screen_size_x(s) - 1)
px = screen_size_x(s) - 1;
if (py != -1 && (u_int)py > screen_size_y(s) - 1)
py = screen_size_y(s) - 1;

log_debug("%s: from %u,%u to %u,%u", __func__, s->cx, s->cy, px, py);
screen_write_set_cursor(ctx, px, py);
}

/* Reverse index (up with scroll). */
void
screen_write_reverseindex(struct screen_write_ctx *ctx, u_int bg)
{
struct screen *s = ctx->s;
struct tty_ctx ttyctx;

if (s->cy == s->rupper) {
#ifdef ENABLE_SIXEL
if (image_free_all(s) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

grid_view_scroll_region_down(s->grid, s->rupper, s->rlower, bg);
screen_write_collect_flush(ctx, 0, __func__);

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

tty_write(tty_cmd_reverseindex, &ttyctx);
} else if (s->cy > 0)
screen_write_set_cursor(ctx, -1, s->cy - 1);

}

/* Set scroll region. */
void
screen_write_scrollregion(struct screen_write_ctx *ctx, u_int rupper,
u_int rlower)
{
struct screen *s = ctx->s;

if (rupper > screen_size_y(s) - 1)
rupper = screen_size_y(s) - 1;
if (rlower > screen_size_y(s) - 1)
rlower = screen_size_y(s) - 1;
if (rupper >= rlower) /* cannot be one line */
return;

screen_write_collect_flush(ctx, 0, __func__);

/* Cursor moves to top-left. */
screen_write_set_cursor(ctx, 0, 0);

s->rupper = rupper;
s->rlower = rlower;
}

/* Line feed. */
void
screen_write_linefeed(struct screen_write_ctx *ctx, int wrapped, u_int bg)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
struct grid_line *gl;
#ifdef ENABLE_SIXEL
int redraw = 0;
#endif
u_int rupper = s->rupper, rlower = s->rlower;

gl = grid_get_line(gd, gd->hsize + s->cy);
if (wrapped)
gl->flags |= GRID_LINE_WRAPPED;

log_debug("%s: at %u,%u (region %u-%u)", __func__, s->cx, s->cy,
rupper, rlower);

if (bg != ctx->bg) {
screen_write_collect_flush(ctx, 1, __func__);
ctx->bg = bg;
}

if (s->cy == s->rlower) {
#ifdef ENABLE_SIXEL
if (rlower == screen_size_y(s) - 1)
redraw = image_scroll_up(s, 1);
else
redraw = image_check_line(s, rupper, rlower - rupper);
if (redraw && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif
grid_view_scroll_region_up(gd, s->rupper, s->rlower, bg);
screen_write_collect_scroll(ctx, bg);
ctx->scrolled++;
} else if (s->cy < screen_size_y(s) - 1)
screen_write_set_cursor(ctx, -1, s->cy + 1);
}

/* Scroll up. */
void
screen_write_scrollup(struct screen_write_ctx *ctx, u_int lines, u_int bg)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
u_int i;

if (lines == 0)
lines = 1;
else if (lines > s->rlower - s->rupper + 1)
lines = s->rlower - s->rupper + 1;

if (bg != ctx->bg) {
screen_write_collect_flush(ctx, 1, __func__);
ctx->bg = bg;
}

#ifdef ENABLE_SIXEL
if (image_scroll_up(s, lines) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

for (i = 0; i < lines; i++) {
grid_view_scroll_region_up(gd, s->rupper, s->rlower, bg);
screen_write_collect_scroll(ctx, bg);
}
ctx->scrolled += lines;
}

/* Scroll down. */
void
screen_write_scrolldown(struct screen_write_ctx *ctx, u_int lines, u_int bg)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
struct tty_ctx ttyctx;
u_int i;

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

if (lines == 0)
lines = 1;
else if (lines > s->rlower - s->rupper + 1)
lines = s->rlower - s->rupper + 1;

#ifdef ENABLE_SIXEL
if (image_free_all(s) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

for (i = 0; i < lines; i++)
grid_view_scroll_region_down(gd, s->rupper, s->rlower, bg);

screen_write_collect_flush(ctx, 0, __func__);
ttyctx.num = lines;
tty_write(tty_cmd_scrolldown, &ttyctx);
}

/* Carriage return (cursor to start of line). */
void
screen_write_carriagereturn(struct screen_write_ctx *ctx)
{
screen_write_set_cursor(ctx, 0, -1);
}

/* Clear to end of screen from cursor. */
void
screen_write_clearendofscreen(struct screen_write_ctx *ctx, u_int bg)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
struct tty_ctx ttyctx;
u_int sx = screen_size_x(s), sy = screen_size_y(s);

#ifdef ENABLE_SIXEL
if (image_check_line(s, s->cy, sy - s->cy) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

/* Scroll into history if it is enabled and clearing entire screen. */
if (s->cx == 0 &&
s->cy == 0 &&
(gd->flags & GRID_HISTORY) &&
ctx->wp != NULL &&
options_get_number(ctx->wp->options, "scroll-on-clear"))
grid_view_clear_history(gd, bg);
else {
if (s->cx <= sx - 1)
grid_view_clear(gd, s->cx, s->cy, sx - s->cx, 1, bg);
grid_view_clear(gd, 0, s->cy + 1, sx, sy - (s->cy + 1), bg);
}

screen_write_collect_clear(ctx, s->cy + 1, sy - (s->cy + 1));
screen_write_collect_flush(ctx, 0, __func__);
tty_write(tty_cmd_clearendofscreen, &ttyctx);
}

/* Clear to start of screen. */
void
screen_write_clearstartofscreen(struct screen_write_ctx *ctx, u_int bg)
{
struct screen *s = ctx->s;
struct tty_ctx ttyctx;
u_int sx = screen_size_x(s);

#ifdef ENABLE_SIXEL
if (image_check_line(s, 0, s->cy - 1) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

if (s->cy > 0)
grid_view_clear(s->grid, 0, 0, sx, s->cy, bg);
if (s->cx > sx - 1)
grid_view_clear(s->grid, 0, s->cy, sx, 1, bg);
else
grid_view_clear(s->grid, 0, s->cy, s->cx + 1, 1, bg);

screen_write_collect_clear(ctx, 0, s->cy);
screen_write_collect_flush(ctx, 0, __func__);
tty_write(tty_cmd_clearstartofscreen, &ttyctx);
}

/* Clear entire screen. */
void
screen_write_clearscreen(struct screen_write_ctx *ctx, u_int bg)
{
struct screen *s = ctx->s;
struct tty_ctx ttyctx;
u_int sx = screen_size_x(s), sy = screen_size_y(s);

#ifdef ENABLE_SIXEL
if (image_free_all(s) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = bg;

/* Scroll into history if it is enabled. */
if ((s->grid->flags & GRID_HISTORY) &&
ctx->wp != NULL &&
options_get_number(ctx->wp->options, "scroll-on-clear"))
grid_view_clear_history(s->grid, bg);
else
grid_view_clear(s->grid, 0, 0, sx, sy, bg);

screen_write_collect_clear(ctx, 0, sy);
tty_write(tty_cmd_clearscreen, &ttyctx);
}

/* Clear entire history. */
void
screen_write_clearhistory(struct screen_write_ctx *ctx)
{
grid_clear_history(ctx->s->grid);
}

/* Force a full redraw. */
void
screen_write_fullredraw(struct screen_write_ctx *ctx)
{
struct tty_ctx ttyctx;

screen_write_collect_flush(ctx, 0, __func__);

screen_write_initctx(ctx, &ttyctx, 1);
if (ttyctx.redraw_cb != NULL)
ttyctx.redraw_cb(&ttyctx);
}

/* Trim collected items. */
static struct screen_write_citem *
screen_write_collect_trim(struct screen_write_ctx *ctx, u_int y, u_int x,
u_int used, int *wrapped)
{
struct screen_write_cline *cl = &ctx->s->write_list[y];
struct screen_write_citem *ci, *ci2, *tmp, *before = NULL;
u_int sx = x, ex = x + used - 1;
u_int csx, cex;

if (TAILQ_EMPTY(&cl->items))
return (NULL);
TAILQ_FOREACH_SAFE(ci, &cl->items, entry, tmp) {
csx = ci->x;
cex = ci->x + ci->used - 1;

/* Item is entirely before. */
if (cex < sx) {
log_debug("%s: %p %u-%u before %u-%u", __func__, ci,
csx, cex, sx, ex);
continue;
}

/* Item is entirely after. */
if (csx > ex) {
log_debug("%s: %p %u-%u after %u-%u", __func__, ci,
csx, cex, sx, ex);
before = ci;
break;
}

/* Item is entirely inside. */
if (csx >= sx && cex <= ex) {
log_debug("%s: %p %u-%u inside %u-%u", __func__, ci,
csx, cex, sx, ex);
TAILQ_REMOVE(&cl->items, ci, entry);
screen_write_free_citem(ci);
if (csx == 0 && ci->wrapped && wrapped != NULL)
*wrapped = 1;
continue;
}

/* Item under the start. */
if (csx < sx && cex >= sx && cex <= ex) {
log_debug("%s: %p %u-%u start %u-%u", __func__, ci,
csx, cex, sx, ex);
ci->used = sx - csx;
log_debug("%s: %p now %u-%u", __func__, ci, ci->x,
ci->x + ci->used + 1);
continue;
}

/* Item covers the end. */
if (cex > ex && csx >= sx && csx <= ex) {
log_debug("%s: %p %u-%u end %u-%u", __func__, ci,
csx, cex, sx, ex);
ci->x = ex + 1;
ci->used = cex - ex;
log_debug("%s: %p now %u-%u", __func__, ci, ci->x,
ci->x + ci->used + 1);
before = ci;
break;
}

/* Item must cover both sides. */
log_debug("%s: %p %u-%u under %u-%u", __func__, ci,
csx, cex, sx, ex);
ci2 = screen_write_get_citem();
ci2->type = ci->type;
ci2->bg = ci->bg;
memcpy(&ci2->gc, &ci->gc, sizeof ci2->gc);
TAILQ_INSERT_AFTER(&cl->items, ci, ci2, entry);

ci->used = sx - csx;
ci2->x = ex + 1;
ci2->used = cex - ex;

log_debug("%s: %p now %u-%u (%p) and %u-%u (%p)", __func__, ci,
ci->x, ci->x + ci->used - 1, ci, ci2->x,
ci2->x + ci2->used - 1, ci2);
before = ci2;
break;
}
return (before);
}

/* Clear collected lines. */
static void
screen_write_collect_clear(struct screen_write_ctx *ctx, u_int y, u_int n)
{
struct screen_write_cline *cl;
u_int i;

for (i = y; i < y + n; i++) {
cl = &ctx->s->write_list[i];
TAILQ_CONCAT(&screen_write_citem_freelist, &cl->items, entry);
}
}

/* Scroll collected lines up. */
static void
screen_write_collect_scroll(struct screen_write_ctx *ctx, u_int bg)
{
struct screen *s = ctx->s;
struct screen_write_cline *cl;
u_int y;
char *saved;
struct screen_write_citem *ci;

log_debug("%s: at %u,%u (region %u-%u)", __func__, s->cx, s->cy,
s->rupper, s->rlower);

screen_write_collect_clear(ctx, s->rupper, 1);
saved = ctx->s->write_list[s->rupper].data;
for (y = s->rupper; y < s->rlower; y++) {
cl = &ctx->s->write_list[y + 1];
TAILQ_CONCAT(&ctx->s->write_list[y].items, &cl->items, entry);
ctx->s->write_list[y].data = cl->data;
}
ctx->s->write_list[s->rlower].data = saved;

ci = screen_write_get_citem();
ci->x = 0;
ci->used = screen_size_x(s);
ci->type = CLEAR;
ci->bg = bg;
TAILQ_INSERT_TAIL(&ctx->s->write_list[s->rlower].items, ci, entry);
}

/* Flush collected lines. */
static void
screen_write_collect_flush(struct screen_write_ctx *ctx, int scroll_only,
const char *from)
{
struct screen *s = ctx->s;
struct screen_write_citem *ci, *tmp;
struct screen_write_cline *cl;
u_int y, cx, cy, last, items = 0;
struct tty_ctx ttyctx;

if (ctx->scrolled != 0) {
log_debug("%s: scrolled %u (region %u-%u)", __func__,
ctx->scrolled, s->rupper, s->rlower);
if (ctx->scrolled > s->rlower - s->rupper + 1)
ctx->scrolled = s->rlower - s->rupper + 1;

screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.num = ctx->scrolled;
ttyctx.bg = ctx->bg;
tty_write(tty_cmd_scrollup, &ttyctx);
}
ctx->scrolled = 0;
ctx->bg = 8;

if (scroll_only)
return;

cx = s->cx; cy = s->cy;
for (y = 0; y < screen_size_y(s); y++) {
cl = &ctx->s->write_list[y];
last = UINT_MAX;
TAILQ_FOREACH_SAFE(ci, &cl->items, entry, tmp) {
if (last != UINT_MAX && ci->x <= last) {
fatalx("collect list not in order: %u <= %u",
ci->x, last);
}
screen_write_set_cursor(ctx, ci->x, y);
if (ci->type == CLEAR) {
screen_write_initctx(ctx, &ttyctx, 1);
ttyctx.bg = ci->bg;
ttyctx.num = ci->used;
tty_write(tty_cmd_clearcharacter, &ttyctx);
} else {
screen_write_initctx(ctx, &ttyctx, 0);
ttyctx.cell = &ci->gc;
ttyctx.wrapped = ci->wrapped;
ttyctx.ptr = cl->data + ci->x;
ttyctx.num = ci->used;
tty_write(tty_cmd_cells, &ttyctx);
}
items++;

TAILQ_REMOVE(&cl->items, ci, entry);
screen_write_free_citem(ci);
last = ci->x;
}
}
s->cx = cx; s->cy = cy;

log_debug("%s: flushed %u items (%s)", __func__, items, from);
}

/* Finish and store collected cells. */
void
screen_write_collect_end(struct screen_write_ctx *ctx)
{
struct screen *s = ctx->s;
struct screen_write_citem *ci = ctx->item, *before;
struct screen_write_cline *cl = &s->write_list[s->cy];
struct grid_cell gc;
u_int xx;
int wrapped = ci->wrapped;

if (ci->used == 0)
return;

before = screen_write_collect_trim(ctx, s->cy, s->cx, ci->used,
&wrapped);
ci->x = s->cx;
ci->wrapped = wrapped;
if (before == NULL)
TAILQ_INSERT_TAIL(&cl->items, ci, entry);
else
TAILQ_INSERT_BEFORE(before, ci, entry);
ctx->item = screen_write_get_citem();

log_debug("%s: %u %.*s (at %u,%u)", __func__, ci->used,
(int)ci->used, cl->data + ci->x, s->cx, s->cy);

if (s->cx != 0) {
for (xx = s->cx; xx > 0; xx--) {
grid_view_get_cell(s->grid, xx, s->cy, &gc);
if (~gc.flags & GRID_FLAG_PADDING)
break;
grid_view_set_cell(s->grid, xx, s->cy,
&grid_default_cell);
}
if (gc.data.width > 1) {
grid_view_set_cell(s->grid, xx, s->cy,
&grid_default_cell);
}
}

#ifdef ENABLE_SIXEL
if (image_check_area(s, s->cx, s->cy, ci->used, 1) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
#endif

grid_view_set_cells(s->grid, s->cx, s->cy, &ci->gc, cl->data + ci->x,
ci->used);
screen_write_set_cursor(ctx, s->cx + ci->used, -1);

for (xx = s->cx; xx < screen_size_x(s); xx++) {
grid_view_get_cell(s->grid, xx, s->cy, &gc);
if (~gc.flags & GRID_FLAG_PADDING)
break;
grid_view_set_cell(s->grid, xx, s->cy, &grid_default_cell);
}
}

/* Write cell data, collecting if necessary. */
void
screen_write_collect_add(struct screen_write_ctx *ctx,
const struct grid_cell *gc)
{
struct screen *s = ctx->s;
struct screen_write_citem *ci;
u_int sx = screen_size_x(s);
int collect;

/*
* Don't need to check that the attributes and whatnot are still the
* same - input_parse will end the collection when anything that isn't
* a plain character is encountered.
*/

collect = 1;
if (gc->data.width != 1 || gc->data.size != 1 || *gc->data.data >= 0x7f)
collect = 0;
else if (gc->attr & GRID_ATTR_CHARSET)
collect = 0;
else if (~s->mode & MODE_WRAP)
collect = 0;
else if (s->mode & MODE_INSERT)
collect = 0;
else if (s->sel != NULL)
collect = 0;
if (!collect) {
screen_write_collect_end(ctx);
screen_write_collect_flush(ctx, 0, __func__);
screen_write_cell(ctx, gc);
return;
}

if (s->cx > sx - 1 || ctx->item->used > sx - 1 - s->cx)
screen_write_collect_end(ctx);
ci = ctx->item; /* may have changed */

if (s->cx > sx - 1) {
log_debug("%s: wrapped at %u,%u", __func__, s->cx, s->cy);
ci->wrapped = 1;
screen_write_linefeed(ctx, 1, 8);
screen_write_set_cursor(ctx, 0, -1);
}

if (ci->used == 0)
memcpy(&ci->gc, gc, sizeof ci->gc);
if (ctx->s->write_list[s->cy].data == NULL)
ctx->s->write_list[s->cy].data = xmalloc(screen_size_x(ctx->s));
ctx->s->write_list[s->cy].data[s->cx + ci->used++] = gc->data.data[0];
}

/* Write cell data. */
void
screen_write_cell(struct screen_write_ctx *ctx, const struct grid_cell *gc)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
const struct utf8_data *ud = &gc->data;
struct grid_line *gl;
struct grid_cell_entry *gce;
struct grid_cell tmp_gc, now_gc;
struct tty_ctx ttyctx;
u_int sx = screen_size_x(s), sy = screen_size_y(s);
u_int width = ud->width, xx, not_wrap;
int selected, skip = 1;

/* Ignore padding cells. */
if (gc->flags & GRID_FLAG_PADDING)
return;

/* Get the previous cell to check for combining. */
if (screen_write_combine(ctx, gc) != 0)
return;

/* Flush any existing scrolling. */
screen_write_collect_flush(ctx, 1, __func__);

/* If this character doesn't fit, ignore it. */
if ((~s->mode & MODE_WRAP) &&
width > 1 &&
(width > sx || (s->cx != sx && s->cx > sx - width)))
return;

/* If in insert mode, make space for the cells. */
if (s->mode & MODE_INSERT) {
grid_view_insert_cells(s->grid, s->cx, s->cy, width, 8);
skip = 0;
}

/* Check this will fit on the current line and wrap if not. */
if ((s->mode & MODE_WRAP) && s->cx > sx - width) {
log_debug("%s: wrapped at %u,%u", __func__, s->cx, s->cy);
screen_write_linefeed(ctx, 1, 8);
screen_write_set_cursor(ctx, 0, -1);
screen_write_collect_flush(ctx, 1, __func__);
}

/* Sanity check cursor position. */
if (s->cx > sx - width || s->cy > sy - 1)
return;
screen_write_initctx(ctx, &ttyctx, 0);

/* Handle overwriting of UTF-8 characters. */
gl = grid_get_line(s->grid, s->grid->hsize + s->cy);
if (gl->flags & GRID_LINE_EXTENDED) {
grid_view_get_cell(gd, s->cx, s->cy, &now_gc);
if (screen_write_overwrite(ctx, &now_gc, width))
skip = 0;
}

/*
* If the new character is UTF-8 wide, fill in padding cells. Have
* already ensured there is enough room.
*/
for (xx = s->cx + 1; xx < s->cx + width; xx++) {
log_debug("%s: new padding at %u,%u", __func__, xx, s->cy);
grid_view_set_padding(gd, xx, s->cy);
skip = 0;
}

/* If no change, do not draw. */
if (skip) {
if (s->cx >= gl->cellsize)
skip = grid_cells_equal(gc, &grid_default_cell);
else {
gce = &gl->celldata[s->cx];
if (gce->flags & GRID_FLAG_EXTENDED)
skip = 0;
else if (gc->flags != gce->flags)
skip = 0;
else if (gc->attr != gce->data.attr)
skip = 0;
else if (gc->fg != gce->data.fg)
skip = 0;
else if (gc->bg != gce->data.bg)
skip = 0;
else if (gc->data.width != 1)
skip = 0;
else if (gc->data.size != 1)
skip = 0;
else if (gce->data.data != gc->data.data[0])
skip = 0;
}
}

/* Update the selected flag and set the cell. */
selected = screen_check_selection(s, s->cx, s->cy);
if (selected && (~gc->flags & GRID_FLAG_SELECTED)) {
memcpy(&tmp_gc, gc, sizeof tmp_gc);
tmp_gc.flags |= GRID_FLAG_SELECTED;
grid_view_set_cell(gd, s->cx, s->cy, &tmp_gc);
} else if (!selected && (gc->flags & GRID_FLAG_SELECTED)) {
memcpy(&tmp_gc, gc, sizeof tmp_gc);
tmp_gc.flags &= ~GRID_FLAG_SELECTED;
grid_view_set_cell(gd, s->cx, s->cy, &tmp_gc);
} else if (!skip)
grid_view_set_cell(gd, s->cx, s->cy, gc);
if (selected)
skip = 0;

/*
* Move the cursor. If not wrapping, stick at the last character and
* replace it.
*/
not_wrap = !(s->mode & MODE_WRAP);
if (s->cx <= sx - not_wrap - width)
screen_write_set_cursor(ctx, s->cx + width, -1);
else
screen_write_set_cursor(ctx, sx - not_wrap, -1);

/* Create space for character in insert mode. */
if (s->mode & MODE_INSERT) {
screen_write_collect_flush(ctx, 0, __func__);
ttyctx.num = width;
tty_write(tty_cmd_insertcharacter, &ttyctx);
}

/* Write to the screen. */
if (!skip) {
if (selected) {
screen_select_cell(s, &tmp_gc, gc);
ttyctx.cell = &tmp_gc;
} else
ttyctx.cell = gc;
tty_write(tty_cmd_cell, &ttyctx);
}
}

/* Combine a UTF-8 zero-width character onto the previous if necessary. */
static int
screen_write_combine(struct screen_write_ctx *ctx, const struct grid_cell *gc)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
const struct utf8_data *ud = &gc->data;
u_int n, cx = s->cx, cy = s->cy;
struct grid_cell last;
struct tty_ctx ttyctx;
int force_wide = 0, zero_width = 0;

/*
* Is this character which makes no sense without being combined? If
* this is true then flag it here and discard the character (return 1)
* if we cannot combine it.
*/
if (utf8_is_zwj(ud))
zero_width = 1;
else if (utf8_is_vs(ud))
zero_width = force_wide = 1;
else if (ud->width == 0)
zero_width = 1;

/* Cannot combine empty character or at left. */
if (ud->size < 2 || cx == 0)
return (zero_width);
log_debug("%s: character %.*s at %u,%u (width %u)", __func__,
(int)ud->size, ud->data, cx, cy, ud->width);

/* Find the cell to combine with. */
n = 1;
grid_view_get_cell(gd, cx - n, cy, &last);
if (cx != 1 && (last.flags & GRID_FLAG_PADDING)) {
n = 2;
grid_view_get_cell(gd, cx - n, cy, &last);
}
if (n != last.data.width || (last.flags & GRID_FLAG_PADDING))
return (zero_width);

/*
* Check if we need to combine characters. This could be zero width
* (set above), a modifier character (with an existing Unicode
* character) or a previous ZWJ.
*/
if (!zero_width) {
if (utf8_is_modifier(ud)) {
if (last.data.size < 2)
return (0);
force_wide = 1;
} else if (!utf8_has_zwj(&last.data))
return (0);
}

/* Check if this combined character would be too long. */
if (last.data.size + ud->size > sizeof last.data.data)
return (0);

/* Combining; flush any pending output. */
screen_write_collect_flush(ctx, 0, __func__);

log_debug("%s: %.*s -> %.*s at %u,%u (offset %u, width %u)", __func__,
(int)ud->size, ud->data, (int)last.data.size, last.data.data,
cx - n, cy, n, last.data.width);

/* Append the data. */
memcpy(last.data.data + last.data.size, ud->data, ud->size);
last.data.size += ud->size;

/* Force the width to 2 for modifiers and variation selector. */
if (last.data.width == 1 && force_wide) {
last.data.width = 2;
n = 2;
cx++;
} else
force_wide = 0;

/* Set the new cell. */
grid_view_set_cell(gd, cx - n, cy, &last);
if (force_wide)
grid_view_set_padding(gd, cx - 1, cy);

/*
* Redraw the combined cell. If forcing the cell to width 2, reset the
* cached cursor position in the tty, since we don't really know
* whether the terminal thought the character was width 1 or width 2
* and what it is going to do now.
*/
screen_write_set_cursor(ctx, cx - n, cy);
screen_write_initctx(ctx, &ttyctx, 0);
ttyctx.cell = &last;
ttyctx.num = force_wide; /* reset cached cursor position */
tty_write(tty_cmd_cell, &ttyctx);
screen_write_set_cursor(ctx, cx, cy);

return (1);
}

/*
* UTF-8 wide characters are a bit of an annoyance. They take up more than one
* cell on the screen, so following cells must not be drawn by marking them as
* padding.
*
* So far, so good. The problem is, when overwriting a padding cell, or a UTF-8
* character, it is necessary to also overwrite any other cells which covered
* by the same character.
*/
static int
screen_write_overwrite(struct screen_write_ctx *ctx, struct grid_cell *gc,
u_int width)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
struct grid_cell tmp_gc;
u_int xx;
int done = 0;

if (gc->flags & GRID_FLAG_PADDING) {
/*
* A padding cell, so clear any following and leading padding
* cells back to the character. Don't overwrite the current
* cell as that happens later anyway.
*/
xx = s->cx + 1;
while (--xx > 0) {
grid_view_get_cell(gd, xx, s->cy, &tmp_gc);
if (~tmp_gc.flags & GRID_FLAG_PADDING)
break;
log_debug("%s: padding at %u,%u", __func__, xx, s->cy);
grid_view_set_cell(gd, xx, s->cy, &grid_default_cell);
}

/* Overwrite the character at the start of this padding. */
log_debug("%s: character at %u,%u", __func__, xx, s->cy);
grid_view_set_cell(gd, xx, s->cy, &grid_default_cell);
done = 1;
}

/*
* Overwrite any padding cells that belong to any UTF-8 characters
* we'll be overwriting with the current character.
*/
if (width != 1 ||
gc->data.width != 1 ||
gc->flags & GRID_FLAG_PADDING) {
xx = s->cx + width - 1;
while (++xx < screen_size_x(s)) {
grid_view_get_cell(gd, xx, s->cy, &tmp_gc);
if (~tmp_gc.flags & GRID_FLAG_PADDING)
break;
log_debug("%s: overwrite at %u,%u", __func__, xx,
s->cy);
grid_view_set_cell(gd, xx, s->cy, &grid_default_cell);
done = 1;
}
}

return (done);
}

/* Set external clipboard. */
void
screen_write_setselection(struct screen_write_ctx *ctx, const char *flags,
u_char *str, u_int len)
{
struct tty_ctx ttyctx;

screen_write_initctx(ctx, &ttyctx, 0);
ttyctx.ptr = str;
ttyctx.ptr2 = __UNCONST(flags);
ttyctx.num = len;

tty_write(tty_cmd_setselection, &ttyctx);
}

/* Write unmodified string. */
void
screen_write_rawstring(struct screen_write_ctx *ctx, u_char *str, u_int len,
int allow_invisible_panes)
{
struct tty_ctx ttyctx;

screen_write_initctx(ctx, &ttyctx, 0);
ttyctx.ptr = str;
ttyctx.num = len;
ttyctx.allow_invisible_panes = allow_invisible_panes;

tty_write(tty_cmd_rawstring, &ttyctx);
}

#ifdef ENABLE_SIXEL
/* Write a SIXEL image. */
void
screen_write_sixelimage(struct screen_write_ctx *ctx, struct sixel_image *si,
u_int bg)
{
struct screen *s = ctx->s;
struct grid *gd = s->grid;
struct tty_ctx ttyctx;
u_int x, y, sx, sy, cx = s->cx, cy = s->cy, i, lines;
struct sixel_image *new;

sixel_size_in_cells(si, &x, &y);
if (x > screen_size_x(s) || y > screen_size_y(s)) {
if (x > screen_size_x(s) - cx)
sx = screen_size_x(s) - cx;
else
sx = x;
if (y > screen_size_y(s) - 1)
sy = screen_size_y(s) - 1;
else
sy = y;
new = sixel_scale(si, 0, 0, 0, y - sy, sx, sy, 1);
sixel_free(si);
si = new;

/* Bail out if the image cannot be scaled. */
if (si == NULL)
return;
sixel_size_in_cells(si, &x, &y);
}

sy = screen_size_y(s) - cy;
if (sy < y) {
lines = y - sy + 1;
if (image_scroll_up(s, lines) && ctx->wp != NULL)
ctx->wp->flags |= PANE_REDRAW;
for (i = 0; i < lines; i++) {
grid_view_scroll_region_up(gd, 0, screen_size_y(s) - 1,
bg);
screen_write_collect_scroll(ctx, bg);
}
ctx->scrolled += lines;
if (lines > cy)
screen_write_cursormove(ctx, -1, 0, 0);
else
screen_write_cursormove(ctx, -1, cy - lines, 0);
}
screen_write_collect_flush(ctx, 0, __func__);

screen_write_initctx(ctx, &ttyctx, 0);
ttyctx.ptr = image_store(s, si);

tty_write(tty_cmd_sixelimage, &ttyctx);

screen_write_cursormove(ctx, 0, cy + y, 0);
}
#endif

/* Turn alternate screen on. */
void
screen_write_alternateon(struct screen_write_ctx *ctx, struct grid_cell *gc,
int cursor)
{
struct tty_ctx ttyctx;
struct window_pane *wp = ctx->wp;

if (wp != NULL && !options_get_number(wp->options, "alternate-screen"))
return;

screen_write_collect_flush(ctx, 0, __func__);
screen_alternate_on(ctx->s, gc, cursor);

screen_write_initctx(ctx, &ttyctx, 1);
if (ttyctx.redraw_cb != NULL)
ttyctx.redraw_cb(&ttyctx);
}

/* Turn alternate screen off. */
void
screen_write_alternateoff(struct screen_write_ctx *ctx, struct grid_cell *gc,
int cursor)
{
struct tty_ctx ttyctx;
struct window_pane *wp = ctx->wp;

if (wp != NULL && !options_get_number(wp->options, "alternate-screen"))
return;

screen_write_collect_flush(ctx, 0, __func__);
screen_alternate_off(ctx->s, gc, cursor);

screen_write_initctx(ctx, &ttyctx, 1);
if (ttyctx.redraw_cb != NULL)
ttyctx.redraw_cb(&ttyctx);
}