Performant and correct set_spans_truncated

the previous implementation used set_string_truncated. This is not only
awkward with this kind of "streaming" string (and therefore lead to an
inefficient and incorrect initial implementation) but that function also
truncates strings of width 1 when there is only a single char available.

The implementation here is performant, correct and also handles the
single width case correctly.
This commit is contained in:
Pascal Kuthe 2023-03-30 17:31:54 +02:00 committed by Blaž Hrastnik
parent e72be52996
commit 67783ddfd4
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GPG key ID: 1238B9C4AD889640

View file

@ -434,28 +434,44 @@ impl Buffer {
}
pub fn set_spans_truncated(&mut self, x: u16, y: u16, spans: &Spans, width: u16) -> (u16, u16) {
let mut remaining_width = width;
let mut alt_x = x;
let (text, styles) =
spans
.0
.iter()
.fold((String::new(), vec![]), |(mut s, mut h), span| {
s.push_str(span.content.as_ref());
let mut styles = span
.styled_graphemes(span.style)
.map(|grapheme| grapheme.style)
.collect();
h.append(&mut styles);
// prevent panic if out of range
if !self.in_bounds(x, y) || width == 0 {
return (x, y);
}
let w = span.width() as u16;
alt_x = alt_x + w;
remaining_width = remaining_width.saturating_sub(w);
let mut x_offset = x as usize;
let max_offset = min(self.area.right(), width.saturating_add(x));
let mut start_index = self.index_of(x, y);
let mut index = self.index_of(max_offset as u16, y);
(s, h)
});
self.set_string_truncated(x, y, &text, width.into(), |idx| styles[idx], true, true);
(x, y)
let content_width = spans.width();
let truncated = content_width > width as usize;
if truncated {
self.content[start_index].set_symbol("");
start_index += 1;
} else {
index -= width as usize - content_width;
}
for span in spans.0.iter().rev() {
for s in span.content.graphemes(true).rev() {
let width = s.width();
if width == 0 {
continue;
}
let start = index - width;
if start < start_index {
break;
}
self.content[start].set_symbol(s);
self.content[start].set_style(span.style);
for i in start + 1..index {
self.content[i].reset();
}
index -= width;
x_offset += width;
}
}
(x_offset as u16, y)
}
pub fn set_spans(&mut self, x: u16, y: u16, spans: &Spans, width: u16) -> (u16, u16) {