use tui::{
buffer::Buffer,
layout::Rect,
text::{Line, Span, Text},
widgets::{Block, Paragraph, Widget},
};
#[derive(Default)]
pub struct List {
pub offset: usize,
}
impl List {
fn list_offset_for(&self, entry_in_view: Option<usize>, height: usize) -> usize {
match entry_in_view {
Some(pos) => match height as usize {
h if (self.offset + h).saturating_sub(1) < pos => pos - h + 1,
_ if self.offset > pos => pos,
_ => self.offset,
},
None => 0,
}
}
}
#[derive(Default)]
pub struct ListProps<'b> {
pub block: Option<Block<'b>>,
pub entry_in_view: Option<usize>,
}
impl List {
pub fn render<'a, 't>(
&mut self,
props: ListProps<'a>,
items: impl IntoIterator<Item = Vec<Span<'t>>>,
area: Rect,
buf: &mut Buffer,
) {
let ListProps {
block,
entry_in_view,
} = props;
let list_area = match block {
Some(b) => {
let inner_area = b.inner(area);
b.render(area, buf);
inner_area
}
None => area,
};
self.offset = self.list_offset_for(entry_in_view, list_area.height as usize);
if list_area.width < 1 || list_area.height < 1 {
return;
}
for (i, vec_of_spans) in items
.into_iter()
.skip(self.offset)
.enumerate()
.take(list_area.height as usize)
{
let (x, y) = (list_area.left(), list_area.top() + i as u16);
Paragraph::new(Text::from(Line::from(vec_of_spans))).render(
Rect {
x,
y,
width: list_area.width,
height: 1,
},
buf,
);
}
}
}