589 lines · 19.2 KB · Rust
RawDownload
use crate::{px, FontId, FontRun, Pixels, PlatformTextSystem, SharedString, TextRun};use collections::HashMap;use std::{iter, sync::Arc}; /// The GPUI line wrapper, used to wrap lines of text to a given width.pub struct LineWrapper {    platform_text_system: Arc<dyn PlatformTextSystem>,    pub(crate) font_id: FontId,    pub(crate) font_size: Pixels,    cached_ascii_char_widths: [Option<Pixels>; 128],    cached_other_char_widths: HashMap<char, Pixels>,} impl LineWrapper {    /// The maximum indent that can be applied to a line.    pub const MAX_INDENT: u32 = 256;     pub(crate) fn new(        font_id: FontId,        font_size: Pixels,        text_system: Arc<dyn PlatformTextSystem>,    ) -> Self {        Self {            platform_text_system: text_system,            font_id,            font_size,            cached_ascii_char_widths: [None; 128],            cached_other_char_widths: HashMap::default(),        }    }     /// Wrap a line of text to the given width with this wrapper's font and font size.    pub fn wrap_line<'a>(        &'a mut self,        line: &'a str,        wrap_width: Pixels,    ) -> impl Iterator<Item = Boundary> + 'a {        let mut width = px(0.);        let mut first_non_whitespace_ix = None;        let mut indent = None;        let mut last_candidate_ix = 0;        let mut last_candidate_width = px(0.);        let mut last_wrap_ix = 0;        let mut prev_c = '\0';        let mut char_indices = line.char_indices();        iter::from_fn(move || {            for (ix, c) in char_indices.by_ref() {                if c == '\n' {                    continue;                }                 if Self::is_word_char(c) {                    if prev_c == ' ' && c != ' ' && first_non_whitespace_ix.is_some() {                        last_candidate_ix = ix;                        last_candidate_width = width;                    }                } else {                    // CJK may not be space separated, e.g.: `Hello world你好世界`                    if c != ' ' && first_non_whitespace_ix.is_some() {                        last_candidate_ix = ix;                        last_candidate_width = width;                    }                }                 if c != ' ' && first_non_whitespace_ix.is_none() {                    first_non_whitespace_ix = Some(ix);                }                 let char_width = self.width_for_char(c);                width += char_width;                if width > wrap_width && ix > last_wrap_ix {                    if let (None, Some(first_non_whitespace_ix)) = (indent, first_non_whitespace_ix)                    {                        indent = Some(                            Self::MAX_INDENT.min((first_non_whitespace_ix - last_wrap_ix) as u32),                        );                    }                     if last_candidate_ix > 0 {                        last_wrap_ix = last_candidate_ix;                        width -= last_candidate_width;                        last_candidate_ix = 0;                    } else {                        last_wrap_ix = ix;                        width = char_width;                    }                     if let Some(indent) = indent {                        width += self.width_for_char(' ') * indent as f32;                    }                     return Some(Boundary::new(last_wrap_ix, indent.unwrap_or(0)));                }                prev_c = c;            }             None        })    }     /// Truncate a line of text to the given width with this wrapper's font and font size.    pub fn truncate_line(        &mut self,        line: SharedString,        truncate_width: Pixels,        ellipsis: Option<&str>,        runs: &mut Vec<TextRun>,    ) -> SharedString {        let mut width = px(0.);        let mut ellipsis_width = px(0.);        if let Some(ellipsis) = ellipsis {            for c in ellipsis.chars() {                ellipsis_width += self.width_for_char(c);            }        }         let mut char_indices = line.char_indices();        let mut truncate_ix = 0;        for (ix, c) in char_indices {            if width + ellipsis_width <= truncate_width {                truncate_ix = ix;            }             let char_width = self.width_for_char(c);            width += char_width;             if width.floor() > truncate_width {                let ellipsis = ellipsis.unwrap_or("");                let result = SharedString::from(format!("{}{}", &line[..truncate_ix], ellipsis));                update_runs_after_truncation(&result, ellipsis, runs);                 return result;            }        }         line    }     pub(crate) fn is_word_char(c: char) -> bool {        // ASCII alphanumeric characters, for English, numbers: `Hello123`, etc.        c.is_ascii_alphanumeric() ||        // Latin script in Unicode for French, German, Spanish, etc.        // Latin-1 Supplement        // https://en.wikipedia.org/wiki/Latin-1_Supplement        matches!(c, '\u{00C0}'..='\u{00FF}') ||        // Latin Extended-A        // https://en.wikipedia.org/wiki/Latin_Extended-A        matches!(c, '\u{0100}'..='\u{017F}') ||        // Latin Extended-B        // https://en.wikipedia.org/wiki/Latin_Extended-B        matches!(c, '\u{0180}'..='\u{024F}') ||        // Cyrillic for Russian, Ukrainian, etc.        // https://en.wikipedia.org/wiki/Cyrillic_script_in_Unicode        matches!(c, '\u{0400}'..='\u{04FF}') ||        // Some other known special characters that should be treated as word characters,        // e.g. `a-b`, `var_name`, `I'm`, '@mention`, `#hashtag`, `100%`, `3.1415`, `2^3`, `a~b`, etc.        matches!(c, '-' | '_' | '.' | '\'' | '$' | '%' | '@' | '#' | '^' | '~' | ',') ||        // Characters that used in URL, e.g. `https://github.com/zed-industries/zed?a=1&b=2` for better wrapping a long URL.        matches!(c,  '/' | ':' | '?' | '&' | '=') ||        // `⋯` character is special used in Zed, to keep this at the end of the line.        matches!(c, '⋯')    }     #[inline(always)]    fn width_for_char(&mut self, c: char) -> Pixels {        if (c as u32) < 128 {            if let Some(cached_width) = self.cached_ascii_char_widths[c as usize] {                cached_width            } else {                let width = self.compute_width_for_char(c);                self.cached_ascii_char_widths[c as usize] = Some(width);                width            }        } else if let Some(cached_width) = self.cached_other_char_widths.get(&c) {            *cached_width        } else {            let width = self.compute_width_for_char(c);            self.cached_other_char_widths.insert(c, width);            width        }    }     fn compute_width_for_char(&self, c: char) -> Pixels {        let mut buffer = [0; 4];        let buffer = c.encode_utf8(&mut buffer);        self.platform_text_system            .layout_line(                buffer,                self.font_size,                &[FontRun {                    len: buffer.len(),                    font_id: self.font_id,                }],            )            .width    }} fn update_runs_after_truncation(result: &str, ellipsis: &str, runs: &mut Vec<TextRun>) {    let mut truncate_at = result.len() - ellipsis.len();    let mut run_end = None;    for (run_index, run) in runs.iter_mut().enumerate() {        if run.len <= truncate_at {            truncate_at -= run.len;        } else {            run.len = truncate_at + ellipsis.len();            run_end = Some(run_index + 1);            break;        }    }    if let Some(run_end) = run_end {        runs.truncate(run_end);    }} /// A boundary between two lines of text.#[derive(Copy, Clone, Debug, PartialEq, Eq)]pub struct Boundary {    /// The index of the last character in a line    pub ix: usize,    /// The indent of the next line.    pub next_indent: u32,} impl Boundary {    fn new(ix: usize, next_indent: u32) -> Self {        Self { ix, next_indent }    }} #[cfg(test)]mod tests {    use super::*;    use crate::{        font, Font, FontFeatures, FontStyle, FontWeight, Hsla, TestAppContext, TestDispatcher,    };    #[cfg(target_os = "macos")]    use crate::{TextRun, WindowTextSystem, WrapBoundary};    use rand::prelude::*;     fn build_wrapper() -> LineWrapper {        let dispatcher = TestDispatcher::new(StdRng::seed_from_u64(0));        let cx = TestAppContext::new(dispatcher, None);        cx.text_system()            .add_fonts(vec![std::fs::read(                "../../assets/fonts/plex-mono/ZedPlexMono-Regular.ttf",            )            .unwrap()            .into()])            .unwrap();        let id = cx.text_system().font_id(&font("Zed Plex Mono")).unwrap();        LineWrapper::new(id, px(16.), cx.text_system().platform_text_system.clone())    }     fn generate_test_runs(input_run_len: &[usize]) -> Vec<TextRun> {        input_run_len            .iter()            .map(|run_len| TextRun {                len: *run_len,                font: Font {                    family: "Dummy".into(),                    features: FontFeatures::default(),                    fallbacks: None,                    weight: FontWeight::default(),                    style: FontStyle::Normal,                },                color: Hsla::default(),                background_color: None,                underline: None,                strikethrough: None,            })            .collect()    }     #[test]    fn test_wrap_line() {        let mut wrapper = build_wrapper();         assert_eq!(            wrapper                .wrap_line("aa bbb cccc ddddd eeee", px(72.))                .collect::<Vec<_>>(),            &[                Boundary::new(7, 0),                Boundary::new(12, 0),                Boundary::new(18, 0)            ],        );        assert_eq!(            wrapper                .wrap_line("aaa aaaaaaaaaaaaaaaaaa", px(72.0))                .collect::<Vec<_>>(),            &[                Boundary::new(4, 0),                Boundary::new(11, 0),                Boundary::new(18, 0)            ],        );        assert_eq!(            wrapper                .wrap_line("     aaaaaaa", px(72.))                .collect::<Vec<_>>(),            &[                Boundary::new(7, 5),                Boundary::new(9, 5),                Boundary::new(11, 5),            ]        );        assert_eq!(            wrapper                .wrap_line("                            ", px(72.))                .collect::<Vec<_>>(),            &[                Boundary::new(7, 0),                Boundary::new(14, 0),                Boundary::new(21, 0)            ]        );        assert_eq!(            wrapper                .wrap_line("          aaaaaaaaaaaaaa", px(72.))                .collect::<Vec<_>>(),            &[                Boundary::new(7, 0),                Boundary::new(14, 3),                Boundary::new(18, 3),                Boundary::new(22, 3),            ]        );    }     #[test]    fn test_truncate_line() {        let mut wrapper = build_wrapper();         fn perform_test(            wrapper: &mut LineWrapper,            text: &'static str,            result: &'static str,            ellipsis: Option<&str>,        ) {            let dummy_run_lens = vec![text.len()];            let mut dummy_runs = generate_test_runs(&dummy_run_lens);            assert_eq!(                wrapper.truncate_line(text.into(), px(220.), ellipsis, &mut dummy_runs),                result            );            assert_eq!(dummy_runs.first().unwrap().len, result.len());        }         perform_test(            &mut wrapper,            "aa bbb cccc ddddd eeee ffff gggg",            "aa bbb cccc ddddd eeee",            None,        );        perform_test(            &mut wrapper,            "aa bbb cccc ddddd eeee ffff gggg",            "aa bbb cccc ddddd eee…",            Some("…"),        );        perform_test(            &mut wrapper,            "aa bbb cccc ddddd eeee ffff gggg",            "aa bbb cccc dddd......",            Some("......"),        );    }     #[test]    fn test_truncate_multiple_runs() {        let mut wrapper = build_wrapper();         fn perform_test(            wrapper: &mut LineWrapper,            text: &'static str,            result: &str,            run_lens: &[usize],            result_run_len: &[usize],            line_width: Pixels,        ) {            let mut dummy_runs = generate_test_runs(run_lens);            assert_eq!(                wrapper.truncate_line(text.into(), line_width, Some("…"), &mut dummy_runs),                result            );            for (run, result_len) in dummy_runs.iter().zip(result_run_len) {                assert_eq!(run.len, *result_len);            }        }        // Case 0: Normal        // Text: abcdefghijkl        // Runs: Run0 { len: 12, ... }        //        // Truncate res: abcd… (truncate_at = 4)        // Run res: Run0 { string: abcd…, len: 7, ... }        perform_test(&mut wrapper, "abcdefghijkl", "abcd…", &[12], &[7], px(50.));        // Case 1: Drop some runs        // Text: abcdefghijkl        // Runs: Run0 { len: 4, ... }, Run1 { len: 4, ... }, Run2 { len: 4, ... }        //        // Truncate res: abcdef… (truncate_at = 6)        // Runs res: Run0 { string: abcd, len: 4, ... }, Run1 { string: ef…, len:        // 5, ... }        perform_test(            &mut wrapper,            "abcdefghijkl",            "abcdef…",            &[4, 4, 4],            &[4, 5],            px(70.),        );        // Case 2: Truncate at start of some run        // Text: abcdefghijkl        // Runs: Run0 { len: 4, ... }, Run1 { len: 4, ... }, Run2 { len: 4, ... }        //        // Truncate res: abcdefgh… (truncate_at = 8)        // Runs res: Run0 { string: abcd, len: 4, ... }, Run1 { string: efgh, len:        // 4, ... }, Run2 { string: …, len: 3, ... }        perform_test(            &mut wrapper,            "abcdefghijkl",            "abcdefgh…",            &[4, 4, 4],            &[4, 4, 3],            px(90.),        );    }     #[test]    fn test_update_run_after_truncation() {        fn perform_test(result: &str, run_lens: &[usize], result_run_lens: &[usize]) {            let mut dummy_runs = generate_test_runs(run_lens);            update_runs_after_truncation(result, "…", &mut dummy_runs);            for (run, result_len) in dummy_runs.iter().zip(result_run_lens) {                assert_eq!(run.len, *result_len);            }        }        // Case 0: Normal        // Text: abcdefghijkl        // Runs: Run0 { len: 12, ... }        //        // Truncate res: abcd… (truncate_at = 4)        // Run res: Run0 { string: abcd…, len: 7, ... }        perform_test("abcd…", &[12], &[7]);        // Case 1: Drop some runs        // Text: abcdefghijkl        // Runs: Run0 { len: 4, ... }, Run1 { len: 4, ... }, Run2 { len: 4, ... }        //        // Truncate res: abcdef… (truncate_at = 6)        // Runs res: Run0 { string: abcd, len: 4, ... }, Run1 { string: ef…, len:        // 5, ... }        perform_test("abcdef…", &[4, 4, 4], &[4, 5]);        // Case 2: Truncate at start of some run        // Text: abcdefghijkl        // Runs: Run0 { len: 4, ... }, Run1 { len: 4, ... }, Run2 { len: 4, ... }        //        // Truncate res: abcdefgh… (truncate_at = 8)        // Runs res: Run0 { string: abcd, len: 4, ... }, Run1 { string: efgh, len:        // 4, ... }, Run2 { string: …, len: 3, ... }        perform_test("abcdefgh…", &[4, 4, 4], &[4, 4, 3]);    }     #[test]    fn test_is_word_char() {        #[track_caller]        fn assert_word(word: &str) {            for c in word.chars() {                assert!(LineWrapper::is_word_char(c), "assertion failed for '{}'", c);            }        }         #[track_caller]        fn assert_not_word(word: &str) {            let found = word.chars().any(|c| !LineWrapper::is_word_char(c));            assert!(found, "assertion failed for '{}'", word);        }         assert_word("Hello123");        assert_word("non-English");        assert_word("var_name");        assert_word("123456");        assert_word("3.1415");        assert_word("10^2");        assert_word("1~2");        assert_word("100%");        assert_word("@mention");        assert_word("#hashtag");        assert_word("$variable");        assert_word("more⋯");         // Space        assert_not_word("foo bar");         // URL case        assert_word("https://github.com/zed-industries/zed/");        assert_word("github.com");        assert_word("a=1&b=2"); 

Lines 1–500 of 589.