Add ExactSizeIterator impl for LayoutRunsIter

This commit is contained in:
Audrey Dutcher 2022-12-28 11:21:14 -08:00 committed by Jeremy Soller
parent 06ad8ff7fb
commit 92b3758909

View file

@ -64,16 +64,26 @@ pub struct LayoutRunIter<'a, 'b> {
buffer: &'b Buffer<'a>,
line_i: usize,
layout_i: usize,
remaining_len: usize,
line_y: i32,
total_layout: i32,
}
impl<'a, 'b> LayoutRunIter<'a, 'b> {
pub fn new(buffer: &'b Buffer<'a>) -> Self {
let total_layout_lines: usize = buffer.lines.iter().map(|line| line.layout_opt().as_ref().map(|layout| layout.len()).unwrap_or_default()).sum();
let top_cropped_layout_lines = total_layout_lines.saturating_sub(buffer.scroll.try_into().unwrap_or_default());
let maximum_lines = buffer.height.checked_div(buffer.metrics.line_height).unwrap_or_default();
let bottom_cropped_layout_lines = if top_cropped_layout_lines > maximum_lines.try_into().unwrap_or_default() {
maximum_lines.try_into().unwrap_or_default()
} else {
top_cropped_layout_lines
};
Self {
buffer,
line_i: 0,
layout_i: 0,
remaining_len: bottom_cropped_layout_lines as usize,
line_y: buffer.metrics.font_size - buffer.metrics.line_height,
total_layout: 0,
}
@ -83,6 +93,10 @@ impl<'a, 'b> LayoutRunIter<'a, 'b> {
impl<'a, 'b> Iterator for LayoutRunIter<'a, 'b> {
type Item = LayoutRun<'b>;
fn size_hint(&self) -> (usize, Option<usize>) {
(self.remaining_len, Some(self.remaining_len))
}
fn next(&mut self) -> Option<Self::Item> {
while let Some(line) = self.buffer.lines.get(self.line_i) {
let shape = line.shape_opt().as_ref()?;
@ -101,6 +115,7 @@ impl<'a, 'b> Iterator for LayoutRunIter<'a, 'b> {
return None;
}
self.remaining_len -= 1;
return Some(LayoutRun {
line_i: self.line_i,
text: line.text(),
@ -118,6 +133,8 @@ impl<'a, 'b> Iterator for LayoutRunIter<'a, 'b> {
}
}
impl<'a, 'b> ExactSizeIterator for LayoutRunIter<'a, 'b> { }
/// Metrics of text
#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
pub struct Metrics {