Files
oak-gpui/crates/gpui/src/text_system/line_wrapper.rs
T
ab59982bf7 Add initial element inspector for Zed development (#31315)
Open inspector with `dev: toggle inspector` from command palette or
`cmd-alt-i` on mac or `ctrl-alt-i` on linux.

https://github.com/user-attachments/assets/54c43034-d40b-414e-ba9b-190bed2e6d2f

* Picking of elements via the mouse, with scroll wheel to inspect
occluded elements.

* Temporary manipulation of the selected element.

* Layout info and JSON-based style manipulation for `Div`.

* Navigation to code that constructed the element.

Big thanks to @as-cii and @maxdeviant for sorting out how to implement
the core of an inspector.

Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>
Co-authored-by: Marshall Bowers <git@maxdeviant.com>
Co-authored-by: Federico Dionisi <code@fdionisi.me>
2025-05-23 23:08:59 +00:00

743 lines
24 KiB
Rust

use crate::{FontId, FontRun, Pixels, PlatformTextSystem, SharedString, TextRun, px};
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,
fragments: &'a [LineFragment],
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 index = 0;
let mut candidates = fragments
.into_iter()
.flat_map(move |fragment| fragment.wrap_boundary_candidates())
.peekable();
iter::from_fn(move || {
for candidate in candidates.by_ref() {
let ix = index;
index += candidate.len_utf8();
let mut new_prev_c = prev_c;
let item_width = match candidate {
WrapBoundaryCandidate::Char { character: c } => {
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);
}
new_prev_c = c;
self.width_for_char(c)
}
WrapBoundaryCandidate::Element {
width: element_width,
..
} => {
if prev_c == ' ' && first_non_whitespace_ix.is_some() {
last_candidate_ix = ix;
last_candidate_width = width;
}
if first_non_whitespace_ix.is_none() {
first_non_whitespace_ix = Some(ix);
}
element_width
}
};
width += item_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 = item_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 = new_prev_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,
truncation_suffix: &str,
runs: &mut Vec<TextRun>,
) -> SharedString {
let mut width = px(0.);
let mut suffix_width = truncation_suffix
.chars()
.map(|c| self.width_for_char(c))
.fold(px(0.0), |a, x| a + x);
let mut char_indices = line.char_indices();
let mut truncate_ix = 0;
for (ix, c) in char_indices {
if width + suffix_width < truncate_width {
truncate_ix = ix;
}
let char_width = self.width_for_char(c);
width += char_width;
if width.floor() > truncate_width {
let result =
SharedString::from(format!("{}{}", &line[..truncate_ix], truncation_suffix));
update_runs_after_truncation(&result, truncation_suffix, 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 fragment of a line that can be wrapped.
pub enum LineFragment<'a> {
/// A text fragment consisting of characters.
Text {
/// The text content of the fragment.
text: &'a str,
},
/// A non-text element with a fixed width.
Element {
/// The width of the element in pixels.
width: Pixels,
/// The UTF-8 encoded length of the element.
len_utf8: usize,
},
}
impl<'a> LineFragment<'a> {
/// Creates a new text fragment from the given text.
pub fn text(text: &'a str) -> Self {
LineFragment::Text { text }
}
/// Creates a new non-text element with the given width and UTF-8 encoded length.
pub fn element(width: Pixels, len_utf8: usize) -> Self {
LineFragment::Element { width, len_utf8 }
}
fn wrap_boundary_candidates(&self) -> impl Iterator<Item = WrapBoundaryCandidate> {
let text = match self {
LineFragment::Text { text } => text,
LineFragment::Element { .. } => "\0",
};
text.chars().map(move |character| {
if let LineFragment::Element { width, len_utf8 } = self {
WrapBoundaryCandidate::Element {
width: *width,
len_utf8: *len_utf8,
}
} else {
WrapBoundaryCandidate::Char { character }
}
})
}
}
enum WrapBoundaryCandidate {
Char { character: char },
Element { width: Pixels, len_utf8: usize },
}
impl WrapBoundaryCandidate {
pub fn len_utf8(&self) -> usize {
match self {
WrapBoundaryCandidate::Char { character } => character.len_utf8(),
WrapBoundaryCandidate::Element { len_utf8: len, .. } => *len,
}
}
}
/// 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, FontFeatures, FontStyle, FontWeight, Hsla, TestAppContext, TestDispatcher, font,
};
#[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::build(dispatcher, None);
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(&[LineFragment::text("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(&[LineFragment::text("aaa aaaaaaaaaaaaaaaaaa")], px(72.0))
.collect::<Vec<_>>(),
&[
Boundary::new(4, 0),
Boundary::new(11, 0),
Boundary::new(18, 0)
],
);
assert_eq!(
wrapper
.wrap_line(&[LineFragment::text(" aaaaaaa")], px(72.))
.collect::<Vec<_>>(),
&[
Boundary::new(7, 5),
Boundary::new(9, 5),
Boundary::new(11, 5),
]
);
assert_eq!(
wrapper
.wrap_line(
&[LineFragment::text(" ")],
px(72.)
)
.collect::<Vec<_>>(),
&[
Boundary::new(7, 0),
Boundary::new(14, 0),
Boundary::new(21, 0)
]
);
assert_eq!(
wrapper
.wrap_line(&[LineFragment::text(" aaaaaaaaaaaaaa")], px(72.))
.collect::<Vec<_>>(),
&[
Boundary::new(7, 0),
Boundary::new(14, 3),
Boundary::new(18, 3),
Boundary::new(22, 3),
]
);
// Test wrapping multiple text fragments
assert_eq!(
wrapper
.wrap_line(
&[
LineFragment::text("aa bbb "),
LineFragment::text("cccc ddddd eeee")
],
px(72.)
)
.collect::<Vec<_>>(),
&[
Boundary::new(7, 0),
Boundary::new(12, 0),
Boundary::new(18, 0)
],
);
// Test wrapping with a mix of text and element fragments
assert_eq!(
wrapper
.wrap_line(
&[
LineFragment::text("aa "),
LineFragment::element(px(20.), 1),
LineFragment::text(" bbb "),
LineFragment::element(px(30.), 1),
LineFragment::text(" cccc")
],
px(72.)
)
.collect::<Vec<_>>(),
&[
Boundary::new(5, 0),
Boundary::new(9, 0),
Boundary::new(11, 0)
],
);
// Test with element at the beginning and text afterward
assert_eq!(
wrapper
.wrap_line(
&[
LineFragment::element(px(50.), 1),
LineFragment::text(" aaaa bbbb cccc dddd")
],
px(72.)
)
.collect::<Vec<_>>(),
&[
Boundary::new(2, 0),
Boundary::new(7, 0),
Boundary::new(12, 0),
Boundary::new(17, 0)
],
);
// Test with a large element that forces wrapping by itself
assert_eq!(
wrapper
.wrap_line(
&[
LineFragment::text("short text "),
LineFragment::element(px(100.), 1),
LineFragment::text(" more text")
],
px(72.)
)
.collect::<Vec<_>>(),
&[
Boundary::new(6, 0),
Boundary::new(11, 0),
Boundary::new(12, 0),
Boundary::new(18, 0)
],
);
}
#[test]
fn test_truncate_line() {
let mut wrapper = build_wrapper();
fn perform_test(
wrapper: &mut LineWrapper,
text: &'static str,
result: &'static str,
ellipsis: &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",
"",
);
perform_test(
&mut wrapper,
"aa bbb cccc ddddd eeee ffff gggg",
"aa bbb cccc ddddd eee…",
"…",
);
perform_test(
&mut wrapper,
"aa bbb cccc ddddd eeee ffff gggg",
"aa bbb cccc dddd......",
"......",
);
}
#[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, "…", &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");
// Latin-1 Supplement
assert_word("ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏ");
// Latin Extended-A
assert_word("ĀāĂ㥹ĆćĈĉĊċČčĎď");
// Latin Extended-B
assert_word("ƀƁƂƃƄƅƆƇƈƉƊƋƌƍƎƏ");
// Cyrillic
assert_word("АБВГДЕЖЗИЙКЛМНОП");
// non-word characters
assert_not_word("你好");
assert_not_word("안녕하세요");
assert_not_word("こんにちは");
assert_not_word("😀😁😂");
assert_not_word("()[]{}<>");
}
// For compatibility with the test macro
#[cfg(target_os = "macos")]
use crate as gpui;
// These seem to vary wildly based on the text system.
#[cfg(target_os = "macos")]
#[crate::test]
fn test_wrap_shaped_line(cx: &mut TestAppContext) {
cx.update(|cx| {
let text_system = WindowTextSystem::new(cx.text_system().clone());
let normal = TextRun {
len: 0,
font: font("Helvetica"),
color: Default::default(),
underline: Default::default(),
strikethrough: None,
background_color: None,
};
let bold = TextRun {
len: 0,
font: font("Helvetica").bold(),
color: Default::default(),
underline: Default::default(),
strikethrough: None,
background_color: None,
};
let text = "aa bbb cccc ddddd eeee".into();
let lines = text_system
.shape_text(
text,
px(16.),
&[
normal.with_len(4),
bold.with_len(5),
normal.with_len(6),
bold.with_len(1),
normal.with_len(7),
],
Some(px(72.)),
None,
)
.unwrap();
assert_eq!(
lines[0].layout.wrap_boundaries(),
&[
WrapBoundary {
run_ix: 0,
glyph_ix: 7
},
WrapBoundary {
run_ix: 0,
glyph_ix: 12
},
WrapBoundary {
run_ix: 0,
glyph_ix: 18
}
],
);
});
}
}