tmate/window-copy.c
Nicholas Marriott 1425738790 y not x :-/
2008-11-12 23:39:25 +00:00

909 lines
22 KiB
C

/* $Id: window-copy.c,v 1.33 2008-11-12 23:39:25 nicm Exp $ */
/*
* Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
*
* 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 <string.h>
#include "tmux.h"
struct screen *window_copy_init(struct window *);
void window_copy_free(struct window *);
void window_copy_resize(struct window *, u_int, u_int);
void window_copy_key(struct window *, struct client *, int);
void window_copy_redraw_lines(struct window *, u_int, u_int);
void window_copy_redraw_screen(struct window *);
void window_copy_write_line(
struct window *, struct screen_write_ctx *, u_int);
void window_copy_write_lines(
struct window *, struct screen_write_ctx *, u_int, u_int);
void window_copy_write_column(
struct window *, struct screen_write_ctx *, u_int);
void window_copy_write_columns(
struct window *, struct screen_write_ctx *, u_int, u_int);
void window_copy_update_cursor(struct window *);
void window_copy_start_selection(struct window *);
int window_copy_update_selection(struct window *);
void window_copy_copy_selection(struct window *, struct client *);
void window_copy_copy_line(
struct window *, char **, size_t *, u_int, u_int, u_int);
int window_copy_is_space(struct window *, u_int, u_int);
u_int window_copy_find_length(struct window *, u_int);
void window_copy_cursor_start_of_line(struct window *);
void window_copy_cursor_end_of_line(struct window *);
void window_copy_cursor_left(struct window *);
void window_copy_cursor_right(struct window *);
void window_copy_cursor_up(struct window *);
void window_copy_cursor_down(struct window *);
void window_copy_cursor_next_word(struct window *);
void window_copy_cursor_previous_word(struct window *);
void window_copy_scroll_left(struct window *, u_int);
void window_copy_scroll_right(struct window *, u_int);
void window_copy_scroll_up(struct window *, u_int);
void window_copy_scroll_down(struct window *, u_int);
const struct window_mode window_copy_mode = {
window_copy_init,
window_copy_free,
window_copy_resize,
window_copy_key
};
struct window_copy_mode_data {
struct screen screen;
u_int ox;
u_int oy;
u_int selx;
u_int sely;
u_int cx;
u_int cy;
};
struct screen *
window_copy_init(struct window *w)
{
struct window_copy_mode_data *data;
struct screen *s;
struct screen_write_ctx ctx;
u_int i;
w->modedata = data = xmalloc(sizeof *data);
data->ox = 0;
data->oy = 0;
data->cx = w->base.cx;
data->cy = w->base.cy;
s = &data->screen;
screen_init(s, screen_size_x(&w->base), screen_size_y(&w->base), 0);
s->cx = data->cx;
s->cy = data->cy;
screen_write_start(&ctx, s, NULL, NULL);
for (i = 0; i < screen_size_y(s); i++)
window_copy_write_line(w, &ctx, i);
screen_write_cursormove(&ctx, data->cx, data->cy);
screen_write_stop(&ctx);
return (s);
}
void
window_copy_free(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
screen_free(&data->screen);
xfree(data);
}
void
window_copy_resize(struct window *w, u_int sx, u_int sy)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
struct screen_write_ctx ctx;
screen_resize(s, sx, sy);
screen_write_start(&ctx, s, NULL, NULL);
window_copy_write_lines(w, &ctx, 0, screen_size_y(s) - 1);
screen_write_stop(&ctx);
window_copy_update_selection(w);
}
void
window_copy_key(struct window *w, struct client *c, int key)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
int table;
table = options_get_number(&c->session->options, "mode-keys");
switch (mode_key_lookup(table, key)) {
case MODEKEY_QUIT:
window_reset_mode(w);
break;
case MODEKEY_LEFT:
window_copy_cursor_left(w);
return;
case MODEKEY_RIGHT:
window_copy_cursor_right(w);
return;
case MODEKEY_UP:
window_copy_cursor_up(w);
return;
case MODEKEY_DOWN:
window_copy_cursor_down(w);
return;
case MODEKEY_PPAGE:
if (data->oy + screen_size_y(s) > screen_hsize(&w->base))
data->oy = screen_hsize(&w->base);
else
data->oy += screen_size_y(s);
window_copy_update_selection(w);
window_copy_redraw_screen(w);
break;
case MODEKEY_NPAGE:
if (data->oy < screen_size_y(s))
data->oy = 0;
else
data->oy -= screen_size_y(s);
window_copy_update_selection(w);
window_copy_redraw_screen(w);
break;
case MODEKEY_STARTSEL:
window_copy_start_selection(w);
break;
case MODEKEY_CLEARSEL:
screen_clear_selection(&data->screen);
window_copy_redraw_screen(w);
break;
case MODEKEY_COPYSEL:
if (c != NULL && c->session != NULL) {
window_copy_copy_selection(w, c);
window_reset_mode(w);
}
break;
case MODEKEY_BOL:
window_copy_cursor_start_of_line(w);
break;
case MODEKEY_EOL:
window_copy_cursor_end_of_line(w);
break;
case MODEKEY_NWORD:
window_copy_cursor_next_word(w);
break;
case MODEKEY_PWORD:
window_copy_cursor_previous_word(w);
break;
default:
break;
}
}
void
window_copy_write_line(struct window *w, struct screen_write_ctx *ctx, u_int py)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
struct grid_cell gc;
char hdr[32];
size_t size;
if (py == 0) {
memcpy(&gc, &grid_default_cell, sizeof gc);
size = xsnprintf(hdr, sizeof hdr,
"[%u,%u/%u]", data->ox, data->oy, screen_hsize(&w->base));
gc.attr |= GRID_ATTR_BRIGHT|GRID_ATTR_REVERSE;
screen_write_cursormove(ctx, screen_size_x(s) - size, 0);
screen_write_puts(ctx, &gc, "%s", hdr);
gc.attr &= ~(GRID_ATTR_BRIGHT|GRID_ATTR_REVERSE);
} else
size = 0;
screen_write_cursormove(ctx, 0, py);
screen_write_copy(ctx, &w->base, data->ox, (screen_hsize(&w->base) -
data->oy) + py, screen_size_x(s) - size, 1);
}
void
window_copy_write_lines(
struct window *w, struct screen_write_ctx *ctx, u_int py, u_int ny)
{
u_int yy;
for (yy = py; yy < py + ny; yy++)
window_copy_write_line(w, ctx, py);
}
void
window_copy_write_column(
struct window *w, struct screen_write_ctx *ctx, u_int px)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
screen_write_cursormove(ctx, px, 0);
screen_write_copy(ctx, &w->base,
data->ox, screen_hsize(&w->base) - data->oy, 1, screen_size_y(s));
}
void
window_copy_write_columns(
struct window *w, struct screen_write_ctx *ctx, u_int px, u_int nx)
{
u_int xx;
for (xx = px; xx < px + nx; xx++)
window_copy_write_column(w, ctx, px);
}
void
window_copy_redraw_lines(struct window *w, u_int py, u_int ny)
{
struct window_copy_mode_data *data = w->modedata;
struct screen_write_ctx ctx;
u_int i;
screen_write_start_window(&ctx, w);
for (i = py; i < py + ny; i++)
window_copy_write_line(w, &ctx, i);
screen_write_cursormove(&ctx, data->cx, data->cy);
screen_write_stop(&ctx);
}
void
window_copy_redraw_screen(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
window_copy_redraw_lines(w, 0, screen_size_y(&data->screen));
}
void
window_copy_update_cursor(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
struct screen_write_ctx ctx;
screen_write_start_window(&ctx, w);
screen_write_cursormove(&ctx, data->cx, data->cy);
screen_write_stop(&ctx);
}
void
window_copy_start_selection(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
data->selx = data->cx + data->ox;
data->sely = screen_hsize(&w->base) + data->cy - data->oy;
s->sel.flag = 1;
window_copy_update_selection(w);
}
int
window_copy_update_selection(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
u_int sx, sy, tx, ty;
if (!s->sel.flag)
return (0);
/* Find top-left of screen. */
tx = data->ox;
ty = screen_hsize(&w->base) - data->oy;
/* Adjust the selection. */
sx = data->selx;
sy = data->sely;
if (sy < ty) {
/* Above it. */
sx = 0;
sy = 0;
} else if (sy > ty + screen_size_y(s) - 1) {
/* Below it. */
sx = screen_size_x(s) - 1;
sy = screen_size_y(s) - 1;
} else if (sx < tx) {
/* To the left. */
sx = 0;
} else if (sx > tx + screen_size_x(s) - 1) {
/* To the right. */
sx = 0;
sy++;
if (sy > screen_size_y(s) - 1)
sy = screen_size_y(s) - 1;
} else {
sx -= tx;
sy -= ty;
}
sy = screen_hsize(s) + sy;
screen_set_selection(s, sx, sy, data->cx, screen_hsize(s) + data->cy);
return (1);
}
void
window_copy_copy_selection(struct window *w, struct client *c)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
char *buf;
size_t off;
u_int i, xx, yy, sx, sy, ex, ey, limit;
if (!s->sel.flag)
return;
buf = xmalloc(1);
off = 0;
*buf = '\0';
/*
* The selection extends from selx,sely to (adjusted) cx,cy on
* the base screen.
*/
/* Find start and end. */
xx = data->cx + data->ox;
yy = screen_hsize(&w->base) + data->cy - data->oy;
if (xx < data->selx || (yy == data->sely && xx < data->selx)) {
sx = xx; sy = yy;
ex = data->selx; ey = data->sely;
} else {
sx = data->selx; sy = data->sely;
ex = xx; ey = yy;
}
/* Trim ex to end of line. */
xx = window_copy_find_length(w, ey);
if (ex > xx)
ex = xx;
/* Copy the lines. */
if (sy == ey)
window_copy_copy_line(w, &buf, &off, sy, sx, ex);
else {
xx = window_copy_find_length(w, sy);
window_copy_copy_line(w, &buf, &off, sy, sx, xx);
if (ey - sy > 1) {
for (i = sy + 1; i < ey - 1; i++) {
xx = window_copy_find_length(w, i);
window_copy_copy_line(w, &buf, &off, i, 0, xx);
}
}
window_copy_copy_line(w, &buf, &off, ey, 0, ex);
}
/* Terminate buffer, overwriting final \n. */
if (off != 0)
buf[off - 1] = '\0';
/* Add the buffer to the stack. */
limit = options_get_number(&c->session->options, "buffer-limit");
paste_add(&c->session->buffers, buf, limit);
xfree(buf);
}
void
window_copy_copy_line(
struct window *w, char **buf, size_t *off, u_int sy, u_int sx, u_int ex)
{
const struct grid_cell *gc;
u_char i, j, xx, data[4];
if (sx > ex)
return;
xx = window_copy_find_length(w, sy);
if (ex > xx)
ex = xx;
if (sx > xx)
sx = xx;
if (sx < ex) {
for (i = sx; i < ex; i++) {
gc = grid_peek_cell(w->base.grid, i, sy);
utf8_split(gc->data, data);
*buf = xrealloc(*buf, 1, (*off) + 4);
for (j = 0; j < sizeof data; j++) {
if (data[j] == 0xff)
break;
(*buf)[(*off)++] = data[j];
}
}
}
*buf = xrealloc(*buf, 1, (*off) + 1);
(*buf)[*off] = '\n';
(*off)++;
}
int
window_copy_is_space(struct window *w, u_int px, u_int py)
{
const struct grid_cell *gc;
const char *spaces = " -_@";
gc = grid_peek_cell(w->base.grid, px, py);
if (gc->flags & GRID_FLAG_PADDING)
return (0);
if (gc->data == 0x00 || gc->data > 0xff)
return (0);
return (strchr(spaces, gc->data) != NULL);
}
u_int
window_copy_find_length(struct window *w, u_int py)
{
const struct grid_cell *gc;
u_int px;
px = w->base.grid->size[py];
while (px > 0) {
gc = grid_peek_cell(w->base.grid, px - 1, py);
if (gc->data != 0x20)
break;
px--;
}
return (px);
}
void
window_copy_cursor_start_of_line(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
if (data->ox != 0)
window_copy_scroll_right(w, data->ox);
data->cx = 0;
if (window_copy_update_selection(w))
window_copy_redraw_lines(w, data->cy, 1);
else
window_copy_update_cursor(w);
}
void
window_copy_cursor_end_of_line(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
u_int px, py;
py = screen_hsize(&w->base) + data->cy - data->oy;
px = window_copy_find_length(w, py);
/* On screen. */
if (px > data->ox && px <= data->ox + screen_size_x(s) - 1)
data->cx = px - data->ox;
/* Off right of screen. */
if (px > data->ox + screen_size_x(s) - 1) {
/* Move cursor to last and scroll screen. */
window_copy_scroll_left(
w, px - data->ox - (screen_size_x(s) - 1));
data->cx = screen_size_x(s) - 1;
}
/* Off left of screen. */
if (px <= data->ox) {
if (px < screen_size_x(s) - 1) {
/* Short enough to fit on screen. */
window_copy_scroll_right(w, data->ox);
data->cx = px;
} else {
/* Too long to fit on screen. */
window_copy_scroll_right(
w, data->ox - (px - (screen_size_x(s) - 1)));
data->cx = screen_size_x(s) - 1;
}
}
if (window_copy_update_selection(w))
window_copy_redraw_lines(w, data->cy, 1);
else
window_copy_update_cursor(w);
}
void
window_copy_cursor_left(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
if (data->cx == 0) {
if (data->ox > 0)
window_copy_scroll_right(w, 1);
else {
window_copy_cursor_up(w);
window_copy_cursor_end_of_line(w);
}
} else {
data->cx--;
if (window_copy_update_selection(w))
window_copy_redraw_lines(w, data->cy, 1);
else
window_copy_update_cursor(w);
}
}
void
window_copy_cursor_right(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
u_int px, py;
py = screen_hsize(&w->base) + data->cy - data->oy;
px = window_copy_find_length(w, py);
if (data->cx >= px) {
window_copy_cursor_start_of_line(w);
window_copy_cursor_down(w);
} else {
data->cx++;
if (window_copy_update_selection(w))
window_copy_redraw_lines(w, data->cy, 1);
else
window_copy_update_cursor(w);
}
}
void
window_copy_cursor_up(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
u_int ox, oy, px, py;
oy = screen_hsize(&w->base) + data->cy - data->oy;
ox = window_copy_find_length(w, oy);
if (data->cy == 0)
window_copy_scroll_down(w, 1);
else {
data->cy--;
if (window_copy_update_selection(w))
window_copy_redraw_lines(w, data->cy, 2);
else
window_copy_update_cursor(w);
}
py = screen_hsize(&w->base) + data->cy - data->oy;
px = window_copy_find_length(w, py);
if (data->cx + data->ox >= px || data->cx + data->ox >= ox)
window_copy_cursor_end_of_line(w);
}
void
window_copy_cursor_down(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
u_int ox, oy, px, py;
oy = screen_hsize(&w->base) + data->cy - data->oy;
ox = window_copy_find_length(w, oy);
if (data->cy == screen_size_y(s) - 1)
window_copy_scroll_up(w, 1);
else {
data->cy++;
if (window_copy_update_selection(w))
window_copy_redraw_lines(w, data->cy - 1, 2);
else
window_copy_update_cursor(w);
}
py = screen_hsize(&w->base) + data->cy - data->oy;
px = window_copy_find_length(w, py);
if (data->cx + data->ox >= px || data->cx + data->ox >= ox)
window_copy_cursor_end_of_line(w);
}
void
window_copy_cursor_next_word(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
u_int px, py, xx, skip;
px = data->ox + data->cx;
py = screen_hsize(&w->base) + data->cy - data->oy;
xx = window_copy_find_length(w, py);
skip = 1;
if (px < xx) {
/* If currently on a space, skip space. */
if (window_copy_is_space(w, px, py))
skip = 0;
} else
skip = 0;
for (;;) {
if (px >= xx) {
if (skip) {
px = xx;
break;
}
while (px >= xx) {
if (data->cy == screen_size_y(s) - 1) {
if (data->oy == 0)
goto out;
}
px = 0;
window_copy_cursor_down(w);
py =screen_hsize(
&w->base) + data->cy - data->oy;
xx = window_copy_find_length(w, py);
}
}
if (skip) {
/* Currently skipping non-space (until space). */
if (window_copy_is_space(w, px, py))
break;
} else {
/* Currently skipping space (until non-space). */
if (!window_copy_is_space(w, px, py))
skip = 1;
}
px++;
}
out:
/* On screen. */
if (px > data->ox && px <= data->ox + screen_size_x(s) - 1)
data->cx = px - data->ox;
/* Off right of screen. */
if (px > data->ox + screen_size_x(s) - 1) {
/* Move cursor to last and scroll screen. */
window_copy_scroll_left(
w, px - data->ox - (screen_size_x(s) - 1));
data->cx = screen_size_x(s) - 1;
}
/* Off left of screen. */
if (px <= data->ox) {
if (px < screen_size_x(s) - 1) {
/* Short enough to fit on screen. */
window_copy_scroll_right(w, data->ox);
data->cx = px;
} else {
/* Too long to fit on screen. */
window_copy_scroll_right(
w, data->ox - (px - (screen_size_x(s) - 1)));
data->cx = screen_size_x(s) - 1;
}
}
if (window_copy_update_selection(w))
window_copy_redraw_lines(w, data->cy, 1);
else
window_copy_update_cursor(w);
}
void
window_copy_cursor_previous_word(struct window *w)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
u_int ox, px, py, skip;
ox = px = data->ox + data->cx;
py = screen_hsize(&w->base) + data->cy - data->oy;
skip = 1;
if (px != 0) {
/* If currently on a space, skip space. */
if (window_copy_is_space(w, px - 1, py))
skip = 0;
}
for (;;) {
if (px == 0) {
if (ox != 0)
break;
while (px == 0) {
if (data->cy == 0 &&
(screen_hsize(&w->base) == 0 ||
data->oy >= screen_hsize(&w->base) - 1))
goto out;
window_copy_cursor_up(w);
py = screen_hsize(
&w->base) + data->cy - data->oy;
px = window_copy_find_length(w, py);
}
goto out;
}
if (skip) {
/* Currently skipping non-space (until space). */
if (window_copy_is_space(w, px - 1, py))
skip = 0;
} else {
/* Currently skipping space (until non-space). */
if (!window_copy_is_space(w, px - 1, py))
break;
}
px--;
}
out:
/* On screen. */
if (px > data->ox && px <= data->ox + screen_size_x(s) - 1)
data->cx = px - data->ox;
/* Off right of screen. */
if (px > data->ox + screen_size_x(s) - 1) {
/* Move cursor to last and scroll screen. */
window_copy_scroll_left(
w, px - data->ox - (screen_size_x(s) - 1));
data->cx = screen_size_x(s) - 1;
}
/* Off left of screen. */
if (px <= data->ox) {
if (px < screen_size_x(s) - 1) {
/* Short enough to fit on screen. */
window_copy_scroll_right(w, data->ox);
data->cx = px;
} else {
/* Too long to fit on screen. */
window_copy_scroll_right(
w, data->ox - (px - (screen_size_x(s) - 1)));
data->cx = screen_size_x(s) - 1;
}
}
if (window_copy_update_selection(w))
window_copy_redraw_lines(w, data->cy, 1);
else
window_copy_update_cursor(w);
}
void
window_copy_scroll_left(struct window *w, u_int nx)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
struct screen_write_ctx ctx;
u_int i;
if (data->ox > SHRT_MAX - nx)
nx = SHRT_MAX - data->ox;
if (nx == 0)
return;
data->ox += nx;
window_copy_update_selection(w);
screen_write_start_window(&ctx, w);
for (i = 1; i < screen_size_y(s); i++) {
screen_write_cursormove(&ctx, 0, i);
screen_write_deletecharacter(&ctx, nx);
}
window_copy_write_columns(w, &ctx, screen_size_x(s) - nx, nx);
window_copy_write_line(w, &ctx, 0);
if (s->sel.flag) {
window_copy_update_selection(w);
window_copy_write_lines(w, &ctx, data->cy, 1);
}
screen_write_cursormove(&ctx, data->cx, data->cy);
screen_write_stop(&ctx);
}
void
window_copy_scroll_right(struct window *w, u_int nx)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
struct screen_write_ctx ctx;
u_int i;
if (data->ox < nx)
nx = data->ox;
if (nx == 0)
return;
data->ox -= nx;
window_copy_update_selection(w);
screen_write_start_window(&ctx, w);
for (i = 1; i < screen_size_y(s); i++) {
screen_write_cursormove(&ctx, 0, i);
screen_write_insertcharacter(&ctx, nx);
}
window_copy_write_columns(w, &ctx, 0, nx);
window_copy_write_line(w, &ctx, 0);
if (s->sel.flag)
window_copy_write_line(w, &ctx, data->cy);
screen_write_cursormove(&ctx, data->cx, data->cy);
screen_write_stop(&ctx);
}
void
window_copy_scroll_up(struct window *w, u_int ny)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
struct screen_write_ctx ctx;
if (data->oy < ny)
ny = data->oy;
if (ny == 0)
return;
data->oy -= ny;
window_copy_update_selection(w);
screen_write_start_window(&ctx, w);
screen_write_cursormove(&ctx, 0, 0);
screen_write_deleteline(&ctx, ny);
window_copy_write_lines(w, &ctx, screen_size_y(s) - ny, ny);
window_copy_write_line(w, &ctx, 0);
if (s->sel.flag && screen_size_y(s) > ny)
window_copy_write_line(w, &ctx, screen_size_y(s) - ny - 1);
screen_write_cursormove(&ctx, data->cx, data->cy);
screen_write_stop(&ctx);
}
void
window_copy_scroll_down(struct window *w, u_int ny)
{
struct window_copy_mode_data *data = w->modedata;
struct screen *s = &data->screen;
struct screen_write_ctx ctx;
if (ny > screen_hsize(&w->base))
return;
if (data->oy > screen_hsize(&w->base) - ny)
ny = screen_hsize(&w->base) - data->oy;
if (ny == 0)
return;
data->oy += ny;
window_copy_update_selection(w);
screen_write_start_window(&ctx, w);
screen_write_cursormove(&ctx, 0, 0);
screen_write_insertline(&ctx, ny);
window_copy_write_lines(w, &ctx, 0, ny);
if (s->sel.flag && screen_size_y(s) > ny)
window_copy_write_line(w, &ctx, ny);
else if (ny == 1) /* nuke position */
window_copy_write_line(w, &ctx, 1);
screen_write_cursormove(&ctx, data->cx, data->cy);
screen_write_stop(&ctx);
}