static const char *update_quote_width(const char *begin, const char *end,
bool utf8, size_t *width)
{
const char *ptr = begin;
while (ptr < end && *width) {
if (utf8) {
size_t left = end - ptr;
const char *next = ptr;
wchar_t wc = next_wchar(&next, &left);
if (!wc || wc == WEOF)
return ptr;
int w = fb_wcwidth(wc);
if (w <= 0)
w = next - ptr > 0 ? next - ptr : 1;
if (*width < w)
return ptr;
*width -= w;
ptr = next;
} else {
if (*ptr & 0x80) {
if (*width < 2)
return ptr;
*width -= 2;
ptr += 2;
} else {
*width -= 1;
++ptr;
}
}
}
return ptr > end ? end : ptr;
}
size_t screen_display_width(const char *ptr, bool utf8)
{
size_t width = 0;
bool ansi = false;
while (*ptr) {
if (ansi) {
if (isalpha(*ptr))
ansi = false;
} else {
if (*ptr == '\033') {
ansi = true;
} else {
if (utf8) {
wchar_t wc = next_wchar(&ptr, NULL);
if (wc == WEOF)
break;
width += fb_wcwidth(wc);
--ptr;
} else {
++width;
}
}
}
++ptr;
}
return width;
}
/**
* 计算一个宽字符的显示宽度
* @param wc 一个宽字符
* @return 该宽字符在编辑器终端上的显示宽度
*/
static size_t display_width_wchar(wchar_t wc)
{
if (wc == L'\n')
return 0;
if (wc == L'\033')
return 1;
int width = fb_wcwidth(wc);
return width < 1 ? 1 : width;
}
/**
* Find newline in [begin, end), truncate at TRUNCATE_WIDTH.
* @param begin The head pointer.
* @param end The off-the-end pointer.
* @param utf8 是否以UTF-8编码
* @return Off-the-end pointer to the first (truncated) line.
*/
static const char *get_truncated_line(const char *begin, const char *end,
bool utf8)
{
const char *code = "[0123456789;";
bool ansi = false;
int width = TRUNCATE_WIDTH;
if (end - begin >= 2 && *begin == ':' && *(begin + 1) == ' ')
width += 2;
for (const char *s = begin; s < end; ++s) {
if (*s == '\n')
return s + 1;
if (*s == '\033') {
ansi = true;
continue;
}
if (ansi) {
if (!memchr(code, *s, sizeof(code) - 1))
ansi = false;
continue;
}
if (*s & 0x80) {
if (utf8) {
const char *ptr = s;
size_t size = end - s;
wchar_t wc = next_wchar(&ptr, &size);
if (wc == WEOF || wc == 0) {
++s;
} else {
width -= fb_wcwidth(wc);
if (width < 0)
return s;
s = ptr - 1;
}
} else {
width -= 2;
if (width < 0)
return s;
++s;
}
if (width == 0)
return (s + 1 > end ? end : s + 1);
} else {
if (--width == 0)
return s + 1;
}
}
return end;
}