tmux/format-draw.c

916 lines
24 KiB
C

/* $OpenBSD$ */
/*
* Copyright (c) 2019 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"
/* Format range. */
struct format_range {
u_int index;
struct screen *s;
u_int start;
u_int end;
enum style_range_type type;
u_int argument;
TAILQ_ENTRY(format_range) entry;
};
TAILQ_HEAD(format_ranges, format_range);
/* Does this range match this style? */
static int
format_is_type(struct format_range *fr, struct style *sy)
{
if (fr->type != sy->range_type)
return (0);
if (fr->type == STYLE_RANGE_WINDOW &&
fr->argument != sy->range_argument)
return (0);
return (1);
}
/* Free a range. */
static void
format_free_range(struct format_ranges *frs, struct format_range *fr)
{
TAILQ_REMOVE(frs, fr, entry);
free(fr);
}
/* Fix range positions. */
static void
format_update_ranges(struct format_ranges *frs, struct screen *s, u_int offset,
u_int start, u_int width)
{
struct format_range *fr, *fr1;
if (frs == NULL)
return;
TAILQ_FOREACH_SAFE(fr, frs, entry, fr1) {
if (fr->s != s)
continue;
if (fr->end <= start || fr->start >= start + width) {
format_free_range(frs, fr);
continue;
}
if (fr->start < start)
fr->start = start;
if (fr->end > start + width)
fr->end = start + width;
if (fr->start == fr->end) {
format_free_range(frs, fr);
continue;
}
fr->start -= start;
fr->end -= start;
fr->start += offset;
fr->end += offset;
}
}
/* Draw a part of the format. */
static void
format_draw_put(struct screen_write_ctx *octx, u_int ocx, u_int ocy,
struct screen *s, struct format_ranges *frs, u_int offset, u_int start,
u_int width)
{
/*
* The offset is how far from the cursor on the target screen; start
* and width how much to copy from the source screen.
*/
screen_write_cursormove(octx, ocx + offset, ocy, 0);
screen_write_fast_copy(octx, s, start, 0, width, 1);
format_update_ranges(frs, s, offset, start, width);
}
/* Draw list part of format. */
static void
format_draw_put_list(struct screen_write_ctx *octx,
u_int ocx, u_int ocy, u_int offset, u_int width, struct screen *list,
struct screen *list_left, struct screen *list_right, int focus_start,
int focus_end, struct format_ranges *frs)
{
u_int start, focus_centre;
/* If there is enough space for the list, draw it entirely. */
if (width >= list->cx) {
format_draw_put(octx, ocx, ocy, list, frs, offset, 0, width);
return;
}
/* The list needs to be trimmed. Try to keep the focus visible. */
focus_centre = focus_start + (focus_end - focus_start) / 2;
if (focus_centre < width / 2)
start = 0;
else
start = focus_centre - width / 2;
if (start + width > list->cx)
start = list->cx - width;
/* Draw <> markers at either side if needed. */
if (start != 0 && width > list_left->cx) {
screen_write_cursormove(octx, ocx + offset, ocy, 0);
screen_write_fast_copy(octx, list_left, 0, 0, list_left->cx, 1);
offset += list_left->cx;
start += list_left->cx;
width -= list_left->cx;
}
if (start + width < list->cx && width > list_right->cx) {
screen_write_cursormove(octx, ocx + offset + width - 1, ocy, 0);
screen_write_fast_copy(octx, list_right, 0, 0, list_right->cx,
1);
width -= list_right->cx;
}
/* Draw the list screen itself. */
format_draw_put(octx, ocx, ocy, list, frs, offset, start, width);
}
/* Draw format with no list. */
static void
format_draw_none(struct screen_write_ctx *octx, u_int available, u_int ocx,
u_int ocy, struct screen *left, struct screen *centre, struct screen *right,
struct format_ranges *frs)
{
u_int width_left, width_centre, width_right;
width_left = left->cx;
width_centre = centre->cx;
width_right = right->cx;
/*
* Try to keep as much of the left and right as possible at the expense
* of the centre.
*/
while (width_left + width_centre + width_right > available) {
if (width_centre > 0)
width_centre--;
else if (width_right > 0)
width_right--;
else
width_left--;
}
/* Write left. */
format_draw_put(octx, ocx, ocy, left, frs, 0, 0, width_left);
/* Write right at available - width_right. */
format_draw_put(octx, ocx, ocy, right, frs,
available - width_right,
right->cx - width_right,
width_right);
/*
* Write centre halfway between
* width_left
* and
* available - width_right.
*/
format_draw_put(octx, ocx, ocy, centre, frs,
width_left
+ ((available - width_right) - width_left) / 2
- width_centre / 2,
centre->cx / 2 - width_centre / 2,
width_centre);
}
/* Draw format with list on the left. */
static void
format_draw_left(struct screen_write_ctx *octx, u_int available, u_int ocx,
u_int ocy, struct screen *left, struct screen *centre, struct screen *right,
struct screen *list, struct screen *list_left, struct screen *list_right,
struct screen *after, int focus_start, int focus_end,
struct format_ranges *frs)
{
u_int width_left, width_centre, width_right;
u_int width_list, width_after;
struct screen_write_ctx ctx;
width_left = left->cx;
width_centre = centre->cx;
width_right = right->cx;
width_list = list->cx;
width_after = after->cx;
/*
* Trim first the centre, then the list, then the right, then after the
* list, then the left.
*/
while (width_left +
width_centre +
width_right +
width_list +
width_after > available) {
if (width_centre > 0)
width_centre--;
else if (width_list > 0)
width_list--;
else if (width_right > 0)
width_right--;
else if (width_after > 0)
width_after--;
else
width_left--;
}
/* If there is no list left, pass off to the no list function. */
if (width_list == 0) {
screen_write_start(&ctx, NULL, left);
screen_write_fast_copy(&ctx, after, 0, 0, width_after, 1);
screen_write_stop(&ctx);
format_draw_none(octx, available, ocx, ocy, left, centre,
right, frs);
return;
}
/* Write left at 0. */
format_draw_put(octx, ocx, ocy, left, frs, 0, 0, width_left);
/* Write right at available - width_right. */
format_draw_put(octx, ocx, ocy, right, frs,
available - width_right,
right->cx - width_right,
width_right);
/* Write after at width_left + width_list. */
format_draw_put(octx, ocx, ocy, after, frs,
width_left + width_list,
0,
width_after);
/*
* Write centre halfway between
* width_left + width_list + width_after
* and
* available - width_right.
*/
format_draw_put(octx, ocx, ocy, centre, frs,
(width_left + width_list + width_after)
+ ((available - width_right)
- (width_left + width_list + width_after)) / 2
- width_centre / 2,
centre->cx / 2 - width_centre / 2,
width_centre);
/*
* The list now goes from
* width_left
* to
* width_left + width_list.
* If there is no focus given, keep the left in focus.
*/
if (focus_start == -1 || focus_end == -1)
focus_start = focus_end = 0;
format_draw_put_list(octx, ocx, ocy, width_left, width_list, list,
list_left, list_right, focus_start, focus_end, frs);
}
/* Draw format with list in the centre. */
static void
format_draw_centre(struct screen_write_ctx *octx, u_int available, u_int ocx,
u_int ocy, struct screen *left, struct screen *centre, struct screen *right,
struct screen *list, struct screen *list_left, struct screen *list_right,
struct screen *after, int focus_start, int focus_end,
struct format_ranges *frs)
{
u_int width_left, width_centre, width_right;
u_int width_list, width_after, middle;
struct screen_write_ctx ctx;
width_left = left->cx;
width_centre = centre->cx;
width_right = right->cx;
width_list = list->cx;
width_after = after->cx;
/*
* Trim first the list, then after the list, then the centre, then the
* right, then the left.
*/
while (width_left +
width_centre +
width_right +
width_list +
width_after > available) {
if (width_list > 0)
width_list--;
else if (width_after > 0)
width_after--;
else if (width_centre > 0)
width_centre--;
else if (width_right > 0)
width_right--;
else
width_left--;
}
/* If there is no list left, pass off to the no list function. */
if (width_list == 0) {
screen_write_start(&ctx, NULL, centre);
screen_write_fast_copy(&ctx, after, 0, 0, width_after, 1);
screen_write_stop(&ctx);
format_draw_none(octx, available, ocx, ocy, left, centre,
right, frs);
return;
}
/* Write left at 0. */
format_draw_put(octx, ocx, ocy, left, frs, 0, 0, width_left);
/* Write right at available - width_right. */
format_draw_put(octx, ocx, ocy, right, frs,
available - width_right,
right->cx - width_right,
width_right);
/*
* All three centre sections are offset from the middle of the
* available space.
*/
middle = (width_left + ((available - width_right) - width_left) / 2);
/*
* Write centre at
* middle - width_list / 2 - width_centre.
*/
format_draw_put(octx, ocx, ocy, centre, frs,
middle - width_list / 2 - width_centre,
0,
width_centre);
/*
* Write after at
* middle - width_list / 2 + width_list
*/
format_draw_put(octx, ocx, ocy, after, frs,
middle - width_list / 2 + width_list,
0,
width_after);
/*
* The list now goes from
* middle - width_list / 2
* to
* middle + width_list / 2
* If there is no focus given, keep the centre in focus.
*/
if (focus_start == -1 || focus_end == -1)
focus_start = focus_end = list->cx / 2;
format_draw_put_list(octx, ocx, ocy, middle - width_list / 2,
width_list, list, list_left, list_right, focus_start, focus_end,
frs);
}
/* Draw format with list on the right. */
static void
format_draw_right(struct screen_write_ctx *octx, u_int available, u_int ocx,
u_int ocy, struct screen *left, struct screen *centre, struct screen *right,
struct screen *list, struct screen *list_left, struct screen *list_right,
struct screen *after, int focus_start, int focus_end,
struct format_ranges *frs)
{
u_int width_left, width_centre, width_right;
u_int width_list, width_after;
struct screen_write_ctx ctx;
width_left = left->cx;
width_centre = centre->cx;
width_right = right->cx;
width_list = list->cx;
width_after = after->cx;
/*
* Trim first the centre, then the list, then the right, then
* after the list, then the left.
*/
while (width_left +
width_centre +
width_right +
width_list +
width_after > available) {
if (width_centre > 0)
width_centre--;
else if (width_list > 0)
width_list--;
else if (width_right > 0)
width_right--;
else if (width_after > 0)
width_after--;
else
width_left--;
}
/* If there is no list left, pass off to the no list function. */
if (width_list == 0) {
screen_write_start(&ctx, NULL, right);
screen_write_fast_copy(&ctx, after, 0, 0, width_after, 1);
screen_write_stop(&ctx);
format_draw_none(octx, available, ocx, ocy, left, centre,
right, frs);
return;
}
/* Write left at 0. */
format_draw_put(octx, ocx, ocy, left, frs, 0, 0, width_left);
/* Write after at available - width_after. */
format_draw_put(octx, ocx, ocy, after, frs,
available - width_after,
after->cx - width_after,
width_after);
/*
* Write right at
* available - width_right - width_list - width_after.
*/
format_draw_put(octx, ocx, ocy, right, frs,
available - width_right - width_list - width_after,
0,
width_right);
/*
* Write centre halfway between
* width_left
* and
* available - width_right - width_list - width_after.
*/
format_draw_put(octx, ocx, ocy, centre, frs,
width_left
+ ((available - width_right - width_list - width_after)
- width_left) / 2
- width_centre / 2,
centre->cx / 2 - width_centre / 2,
width_centre);
/*
* The list now goes from
* available - width_list - width_after
* to
* available - width_after
* If there is no focus given, keep the right in focus.
*/
if (focus_start == -1 || focus_end == -1)
focus_start = focus_end = 0;
format_draw_put_list(octx, ocx, ocy, available - width_list -
width_after, width_list, list, list_left, list_right, focus_start,
focus_end, frs);
}
/* Draw a format to a screen. */
void
format_draw(struct screen_write_ctx *octx, const struct grid_cell *base,
u_int available, const char *expanded, struct style_ranges *srs)
{
enum { LEFT,
CENTRE,
RIGHT,
LIST,
LIST_LEFT,
LIST_RIGHT,
AFTER,
TOTAL } current = LEFT, last = LEFT;
const char *names[] = { "LEFT",
"CENTRE",
"RIGHT",
"LIST",
"LIST_LEFT",
"LIST_RIGHT",
"AFTER" };
size_t size = strlen(expanded);
struct screen *os = octx->s, s[TOTAL];
struct screen_write_ctx ctx[TOTAL];
u_int ocx = os->cx, ocy = os->cy, i, width[TOTAL];
u_int map[] = { LEFT, LEFT, CENTRE, RIGHT };
int focus_start = -1, focus_end = -1;
int list_state = -1, fill = -1;
enum style_align list_align = STYLE_ALIGN_DEFAULT;
struct grid_cell gc, current_default;
struct style sy, saved_sy;
struct utf8_data *ud = &sy.gc.data;
const char *cp, *end;
enum utf8_state more;
char *tmp;
struct format_range *fr = NULL, *fr1;
struct format_ranges frs;
struct style_range *sr;
memcpy(&current_default, base, sizeof current_default);
style_set(&sy, &current_default);
TAILQ_INIT(&frs);
log_debug("%s: %s", __func__, expanded);
/*
* We build three screens for left, right, centre alignment, one for
* the list, one for anything after the list and two for the list left
* and right markers.
*/
for (i = 0; i < TOTAL; i++) {
screen_init(&s[i], size, 1, 0);
screen_write_start(&ctx[i], NULL, &s[i]);
screen_write_clearendofline(&ctx[i], current_default.bg);
width[i] = 0;
}
/*
* Walk the string and add to the corresponding screens,
* parsing styles as we go.
*/
cp = expanded;
while (*cp != '\0') {
if (cp[0] != '#' || cp[1] != '[') {
/* See if this is a UTF-8 character. */
if ((more = utf8_open(ud, *cp)) == UTF8_MORE) {
while (*++cp != '\0' && more == UTF8_MORE)
more = utf8_append(ud, *cp);
if (more != UTF8_DONE)
cp -= ud->have;
}
/* Not a UTF-8 character - ASCII or not valid. */
if (more != UTF8_DONE) {
if (*cp < 0x20 || *cp > 0x7e) {
/* Ignore nonprintable characters. */
cp++;
continue;
}
utf8_set(ud, *cp);
cp++;
}
/* Draw the cell to the current screen. */
screen_write_cell(&ctx[current], &sy.gc);
width[current] += ud->width;
continue;
}
/* This is a style. Work out where the end is and parse it. */
end = format_skip(cp + 2, "]");
if (end == NULL) {
log_debug("%s: no terminating ] at '%s'", __func__,
cp + 2);
TAILQ_FOREACH_SAFE(fr, &frs, entry, fr1)
format_free_range(&frs, fr);
goto out;
}
tmp = xstrndup(cp + 2, end - (cp + 2));
style_copy(&saved_sy, &sy);
if (style_parse(&sy, &current_default, tmp) != 0) {
log_debug("%s: invalid style '%s'", __func__, tmp);
free(tmp);
cp = end + 1;
continue;
}
log_debug("%s: style '%s' -> '%s'", __func__, tmp,
style_tostring(&sy));
free(tmp);
/* If this style has a fill colour, store it for later. */
if (sy.fill != 8)
fill = sy.fill;
/* If this style pushed or popped the default, update it. */
if (sy.default_type == STYLE_DEFAULT_PUSH) {
memcpy(&current_default, &saved_sy.gc, sizeof current_default);
sy.default_type = STYLE_DEFAULT_BASE;
} else if (sy.default_type == STYLE_DEFAULT_POP) {
memcpy(&current_default, base, sizeof current_default);
sy.default_type = STYLE_DEFAULT_BASE;
}
/* Check the list state. */
switch (sy.list) {
case STYLE_LIST_ON:
/*
* Entering the list, exiting a marker, or exiting the
* focus.
*/
if (list_state != 0) {
if (fr != NULL) { /* abort any region */
free(fr);
fr = NULL;
}
list_state = 0;
list_align = sy.align;
}
/* End the focus if started. */
if (focus_start != -1 && focus_end == -1)
focus_end = s[LIST].cx;
current = LIST;
break;
case STYLE_LIST_FOCUS:
/* Entering the focus. */
if (list_state != 0) /* not inside the list */
break;
if (focus_start == -1) /* focus already started */
focus_start = s[LIST].cx;
break;
case STYLE_LIST_OFF:
/* Exiting or outside the list. */
if (list_state == 0) {
if (fr != NULL) { /* abort any region */
free(fr);
fr = NULL;
}
if (focus_start != -1 && focus_end == -1)
focus_end = s[LIST].cx;
map[list_align] = AFTER;
if (list_align == STYLE_ALIGN_LEFT)
map[STYLE_ALIGN_DEFAULT] = AFTER;
list_state = 1;
}
current = map[sy.align];
break;
case STYLE_LIST_LEFT_MARKER:
/* Entering left marker. */
if (list_state != 0) /* not inside the list */
break;
if (s[LIST_LEFT].cx != 0) /* already have marker */
break;
if (fr != NULL) { /* abort any region */
free(fr);
fr = NULL;
}
if (focus_start != -1 && focus_end == -1)
focus_start = focus_end = -1;
current = LIST_LEFT;
break;
case STYLE_LIST_RIGHT_MARKER:
/* Entering right marker. */
if (list_state != 0) /* not inside the list */
break;
if (s[LIST_RIGHT].cx != 0) /* already have marker */
break;
if (fr != NULL) { /* abort any region */
free(fr);
fr = NULL;
}
if (focus_start != -1 && focus_end == -1)
focus_start = focus_end = -1;
current = LIST_RIGHT;
break;
}
if (current != last) {
log_debug("%s: change %s -> %s", __func__,
names[last], names[current]);
last = current;
}
/*
* Check if the range style has changed and if so end the
* current range and start a new one if needed.
*/
if (srs != NULL) {
if (fr != NULL && !format_is_type(fr, &sy)) {
if (s[current].cx != fr->start) {
fr->end = s[current].cx + 1;
TAILQ_INSERT_TAIL(&frs, fr, entry);
} else
free(fr);
fr = NULL;
}
if (fr == NULL && sy.range_type != STYLE_RANGE_NONE) {
fr = xcalloc(1, sizeof *fr);
fr->index = current;
fr->s = &s[current];
fr->start = s[current].cx;
fr->type = sy.range_type;
fr->argument = sy.range_argument;
}
}
cp = end + 1;
}
free(fr);
for (i = 0; i < TOTAL; i++) {
screen_write_stop(&ctx[i]);
log_debug("%s: width %s is %u", __func__, names[i], width[i]);
}
if (focus_start != -1 && focus_end != -1)
log_debug("%s: focus %d-%d", __func__, focus_start, focus_end);
TAILQ_FOREACH(fr, &frs, entry) {
log_debug("%s: range %d|%u is %s %u-%u", __func__, fr->type,
fr->argument, names[fr->index], fr->start, fr->end);
}
/* Clear the available area. */
if (fill != -1) {
memcpy(&gc, &grid_default_cell, sizeof gc);
gc.bg = fill;
for (i = 0; i < available; i++)
screen_write_putc(octx, &gc, ' ');
}
/*
* Draw the screens. How they are arranged depends on where the list
* appearsq.
*/
switch (list_align) {
case STYLE_ALIGN_DEFAULT:
/* No list. */
format_draw_none(octx, available, ocx, ocy, &s[LEFT],
&s[CENTRE], &s[RIGHT], &frs);
break;
case STYLE_ALIGN_LEFT:
/* List is part of the left. */
format_draw_left(octx, available, ocx, ocy, &s[LEFT],
&s[CENTRE], &s[RIGHT], &s[LIST], &s[LIST_LEFT],
&s[LIST_RIGHT], &s[AFTER], focus_start, focus_end, &frs);
break;
case STYLE_ALIGN_CENTRE:
/* List is part of the centre. */
format_draw_centre(octx, available, ocx, ocy, &s[LEFT],
&s[CENTRE], &s[RIGHT], &s[LIST], &s[LIST_LEFT],
&s[LIST_RIGHT], &s[AFTER], focus_start, focus_end, &frs);
break;
case STYLE_ALIGN_RIGHT:
/* List is part of the right. */
format_draw_right(octx, available, ocx, ocy, &s[LEFT],
&s[CENTRE], &s[RIGHT], &s[LIST], &s[LIST_LEFT],
&s[LIST_RIGHT], &s[AFTER], focus_start, focus_end, &frs);
break;
}
/* Create ranges to return. */
TAILQ_FOREACH_SAFE(fr, &frs, entry, fr1) {
sr = xcalloc(1, sizeof *sr);
sr->type = fr->type;
sr->argument = fr->argument;
sr->start = fr->start;
sr->end = fr->end;
TAILQ_INSERT_TAIL(srs, sr, entry);
log_debug("%s: range %d|%u at %u-%u", __func__, sr->type,
sr->argument, sr->start, sr->end);
format_free_range(&frs, fr);
}
out:
/* Free the screens. */
for (i = 0; i < TOTAL; i++)
screen_free(&s[i]);
/* Restore the original cursor position. */
screen_write_cursormove(octx, ocx, ocy, 0);
}
/* Get width, taking #[] into account. */
u_int
format_width(const char *expanded)
{
const char *cp, *end;
u_int width = 0;
struct utf8_data ud;
enum utf8_state more;
cp = expanded;
while (*cp != '\0') {
if (cp[0] == '#' && cp[1] == '[') {
end = format_skip(cp + 2, "]");
if (end == NULL)
return 0;
cp = end + 1;
} else if ((more = utf8_open(&ud, *cp)) == UTF8_MORE) {
while (*++cp != '\0' && more == UTF8_MORE)
more = utf8_append(&ud, *cp);
if (more == UTF8_DONE)
width += ud.width;
else
cp -= ud.have;
} else if (*cp > 0x1f && *cp < 0x7f) {
width++;
cp++;
} else
cp++;
}
return (width);
}
/* Trim on the left, taking #[] into account. */
char *
format_trim_left(const char *expanded, u_int limit)
{
char *copy, *out;
const char *cp = expanded, *end;
u_int width = 0;
struct utf8_data ud;
enum utf8_state more;
out = copy = xmalloc(strlen(expanded) + 1);
while (*cp != '\0') {
if (cp[0] == '#' && cp[1] == '[') {
end = format_skip(cp + 2, "]");
if (end == NULL)
break;
memcpy(out, cp, end + 1 - cp);
out += (end + 1 - cp);
cp = end + 1;
} else if ((more = utf8_open(&ud, *cp)) == UTF8_MORE) {
while (*++cp != '\0' && more == UTF8_MORE)
more = utf8_append(&ud, *cp);
if (more == UTF8_DONE) {
if (width + ud.width <= limit) {
memcpy(out, ud.data, ud.size);
out += ud.size;
}
width += ud.width;
} else {
cp -= ud.have;
cp++;
}
} else if (*cp > 0x1f && *cp < 0x7f) {
if (width + 1 <= limit)
*out++ = *cp;
width++;
cp++;
} else
cp++;
}
*out = '\0';
return (copy);
}
/* Trim on the right, taking #[] into account. */
char *
format_trim_right(const char *expanded, u_int limit)
{
char *copy, *out;
const char *cp = expanded, *end;
u_int width = 0, total_width, skip;
struct utf8_data ud;
enum utf8_state more;
total_width = format_width(expanded);
if (total_width <= limit)
return (xstrdup(expanded));
skip = total_width - limit;
out = copy = xmalloc(strlen(expanded) + 1);
while (*cp != '\0') {
if (cp[0] == '#' && cp[1] == '[') {
end = format_skip(cp + 2, "]");
if (end == NULL)
break;
memcpy(out, cp, end + 1 - cp);
out += (end + 1 - cp);
cp = end + 1;
} else if ((more = utf8_open(&ud, *cp)) == UTF8_MORE) {
while (*++cp != '\0' && more == UTF8_MORE)
more = utf8_append(&ud, *cp);
if (more == UTF8_DONE) {
if (width >= skip) {
memcpy(out, ud.data, ud.size);
out += ud.size;
}
width += ud.width;
} else {
cp -= ud.have;
cp++;
}
} else if (*cp > 0x1f && *cp < 0x7f) {
if (width >= skip)
*out++ = *cp;
width++;
cp++;
} else
cp++;
}
*out = '\0';
return (copy);
}