catboy/edit.c

83 lines
2.1 KiB
C

/* Copyright (C) 2020 C. McEnroe <june@causal.agency>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <wchar.h>
#include "chat.h"
enum { Cap = 512 };
static wchar_t buf[Cap];
static size_t len;
static size_t pos;
char *editHead(void) {
static char mbs[MB_LEN_MAX * Cap];
const wchar_t *ptr = buf;
size_t n = wcsnrtombs(mbs, &ptr, pos, sizeof(mbs) - 1, NULL);
assert(n != (size_t)-1);
mbs[n] = '\0';
return mbs;
}
char *editTail(void) {
static char mbs[MB_LEN_MAX * Cap];
const wchar_t *ptr = &buf[pos];
size_t n = wcsnrtombs(mbs, &ptr, len - pos, sizeof(mbs) - 1, NULL);
assert(n != (size_t)-1);
mbs[n] = '\0';
return mbs;
}
static void reserve(size_t index, size_t count) {
if (len + count > Cap) return;
memmove(&buf[index + count], &buf[index], sizeof(*buf) * (len - index));
len += count;
}
static void delete(size_t index, size_t count) {
if (index + count > len) return;
memmove(
&buf[index], &buf[index + count], sizeof(*buf) * (len - index - count)
);
len -= count;
}
void edit(size_t id, enum Edit op, wchar_t ch) {
switch (op) {
break; case EditHome: pos = 0;
break; case EditEnd: pos = len;
break; case EditLeft: if (pos) pos--;
break; case EditRight: if (pos < len) pos++;
break; case EditKill: len = pos = 0;
break; case EditErase: if (pos) delete(--pos, 1);
break; case EditInsert: {
reserve(pos, 1);
if (pos < Cap) buf[pos++] = ch;
}
break; case EditEnter: {
pos = 0;
command(id, editTail());
len = 0;
}
}
}