1#![allow(missing_docs)]
  2
  3use std::ops::Range;
  4
  5use gpui::{FontWeight, HighlightStyle, StyledText};
  6
  7use crate::{prelude::*, LabelCommon, LabelLike, LabelSize, LineHeightStyle};
  8
  9#[derive(IntoElement)]
 10pub struct HighlightedLabel {
 11    base: LabelLike,
 12    label: SharedString,
 13    highlight_indices: Vec<usize>,
 14}
 15
 16impl HighlightedLabel {
 17    /// Constructs a label with the given characters highlighted.
 18    /// Characters are identified by UTF-8 byte position.
 19    pub fn new(label: impl Into<SharedString>, highlight_indices: Vec<usize>) -> Self {
 20        Self {
 21            base: LabelLike::new(),
 22            label: label.into(),
 23            highlight_indices,
 24        }
 25    }
 26}
 27
 28impl LabelCommon for HighlightedLabel {
 29    fn size(mut self, size: LabelSize) -> Self {
 30        self.base = self.base.size(size);
 31        self
 32    }
 33
 34    fn weight(mut self, weight: FontWeight) -> Self {
 35        self.base = self.base.weight(weight);
 36        self
 37    }
 38
 39    fn line_height_style(mut self, line_height_style: LineHeightStyle) -> Self {
 40        self.base = self.base.line_height_style(line_height_style);
 41        self
 42    }
 43
 44    fn color(mut self, color: Color) -> Self {
 45        self.base = self.base.color(color);
 46        self
 47    }
 48
 49    fn strikethrough(mut self, strikethrough: bool) -> Self {
 50        self.base = self.base.strikethrough(strikethrough);
 51        self
 52    }
 53
 54    fn italic(mut self, italic: bool) -> Self {
 55        self.base = self.base.italic(italic);
 56        self
 57    }
 58
 59    fn alpha(mut self, alpha: f32) -> Self {
 60        self.base = self.base.alpha(alpha);
 61        self
 62    }
 63
 64    fn underline(mut self, underline: bool) -> Self {
 65        self.base = self.base.underline(underline);
 66        self
 67    }
 68}
 69
 70pub fn highlight_ranges(
 71    text: &str,
 72    indices: &[usize],
 73    style: HighlightStyle,
 74) -> Vec<(Range<usize>, HighlightStyle)> {
 75    let mut highlight_indices = indices.iter().copied().peekable();
 76    let mut highlights: Vec<(Range<usize>, HighlightStyle)> = Vec::new();
 77
 78    while let Some(start_ix) = highlight_indices.next() {
 79        let mut end_ix = start_ix;
 80
 81        loop {
 82            end_ix = end_ix + text[end_ix..].chars().next().unwrap().len_utf8();
 83            if let Some(&next_ix) = highlight_indices.peek() {
 84                if next_ix == end_ix {
 85                    end_ix = next_ix;
 86                    highlight_indices.next();
 87                    continue;
 88                }
 89            }
 90            break;
 91        }
 92
 93        highlights.push((start_ix..end_ix, style));
 94    }
 95
 96    highlights
 97}
 98
 99impl RenderOnce for HighlightedLabel {
100    fn render(self, cx: &mut WindowContext) -> impl IntoElement {
101        let highlight_color = cx.theme().colors().text_accent;
102
103        let highlights = highlight_ranges(
104            &self.label,
105            &self.highlight_indices,
106            HighlightStyle {
107                color: Some(highlight_color),
108                ..Default::default()
109            },
110        );
111
112        let mut text_style = cx.text_style();
113        text_style.color = self.base.color.color(cx);
114
115        self.base
116            .child(StyledText::new(self.label).with_highlights(&text_style, highlights))
117    }
118}