freya_code_editor/
metrics.rs

1use freya_core::prelude::consume_root_context;
2use freya_engine::prelude::*;
3use ropey::Rope;
4use tree_sitter::InputEdit;
5
6use crate::{
7    editor_theme::EditorSyntaxTheme,
8    syntax::*,
9};
10
11pub struct EditorMetrics {
12    pub(crate) syntax_blocks: SyntaxBlocks,
13    pub(crate) longest_width: f32,
14    pub(crate) char_width: f32,
15    pub(crate) highlighter: SyntaxHighlighter,
16}
17
18impl Default for EditorMetrics {
19    fn default() -> Self {
20        Self::new()
21    }
22}
23
24impl EditorMetrics {
25    pub fn new() -> Self {
26        Self {
27            syntax_blocks: SyntaxBlocks::default(),
28            longest_width: 0.0,
29            char_width: 0.0,
30            highlighter: SyntaxHighlighter::new(),
31        }
32    }
33
34    pub fn measure_longest_line(&mut self, font_size: f32, font_family: &str, rope: &Rope) {
35        // We assume the font used is monospaced.
36
37        // Calculate character width by measuring a reference character
38        let font_collection = consume_root_context::<FontCollection>();
39        let mut paragraph_style = ParagraphStyle::default();
40        let mut text_style = TextStyle::default();
41        text_style.set_font_size(font_size);
42        text_style.set_font_families(&[font_family]);
43        paragraph_style.set_text_style(&text_style);
44        let mut paragraph_builder = ParagraphBuilder::new(&paragraph_style, font_collection);
45
46        // Measure a single character to get the monospace character width
47        paragraph_builder.add_text("W");
48        let mut paragraph = paragraph_builder.build();
49        paragraph.layout(f32::MAX);
50        let char_width = paragraph.longest_line();
51
52        // Find the line with the maximum character count
53        let max_chars = rope.lines().map(|line| line.len_chars()).max().unwrap_or(0);
54
55        self.char_width = char_width;
56        self.longest_width = max_chars as f32 * char_width;
57    }
58
59    pub fn run_parser(&mut self, rope: &Rope, edit: Option<InputEdit>, theme: &EditorSyntaxTheme) {
60        self.highlighter
61            .parse(rope, &mut self.syntax_blocks, edit, theme);
62    }
63}
freya_code_editor/metrics.rs

freya_code_editor/
metrics.rs
