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