cosmic-text/src/edit/syntect.rs

277 lines
8 KiB
Rust

#[cfg(not(feature = "std"))]
use alloc::{
string::String,
vec::Vec,
};
#[cfg(feature = "std")]
use std::{
fs,
io,
path::Path,
};
use syntect::highlighting::{
FontStyle,
Highlighter,
HighlightState,
RangedHighlightIterator,
Theme,
ThemeSet,
};
use syntect::parsing::{
ParseState,
ScopeStack,
SyntaxReference,
SyntaxSet,
};
use crate::{
Action,
AttrsList,
Buffer,
Color,
Cursor,
Edit,
Editor,
Style,
Weight,
Wrap,
};
pub struct SyntaxSystem {
pub syntax_set: SyntaxSet,
pub theme_set: ThemeSet,
}
impl SyntaxSystem {
/// Create a new [`SyntaxSystem`]
pub fn new() -> Self {
Self {
//TODO: store newlines in buffer
syntax_set: SyntaxSet::load_defaults_nonewlines(),
theme_set: ThemeSet::load_defaults(),
}
}
}
/// A wrapper of [`Editor`] with syntax highlighting provided by [`SyntaxSystem`]
pub struct SyntaxEditor<'a> {
editor: Editor<'a>,
syntax_system: &'a SyntaxSystem,
syntax: &'a SyntaxReference,
theme: &'a Theme,
highlighter: Highlighter<'a>,
syntax_cache: Vec<(ParseState, HighlightState)>,
}
impl<'a> SyntaxEditor<'a> {
/// Create a new [`SyntaxEditor`] with the provided [`Buffer`], [`SyntaxSystem`], and theme name.
///
/// A good default theme name is "base16-eighties.dark".
///
/// Returns None if theme not found
pub fn new(buffer: Buffer<'a>, syntax_system: &'a SyntaxSystem, theme_name: &str) -> Option<Self> {
let editor = Editor::new(buffer);
let syntax = syntax_system.syntax_set.find_syntax_plain_text();
let theme = syntax_system.theme_set.themes.get(theme_name)?;
let highlighter = Highlighter::new(theme);
Some(Self {
editor,
syntax_system,
syntax,
theme,
highlighter,
syntax_cache: Vec::new(),
})
}
/// Load text from a file, and also set syntax to the best option
///
/// ## Errors
///
/// Returns an [`io::Error`] if reading the file fails
#[cfg(feature = "std")]
pub fn load_text<P: AsRef<Path>>(&mut self, path: P, attrs: crate::Attrs<'a>) -> io::Result<()> {
let path = path.as_ref();
let text = fs::read_to_string(path)?;
self.editor.buffer_mut().set_text(&text, attrs);
//TODO: re-use text
self.syntax = match self.syntax_system.syntax_set.find_syntax_for_file(path) {
Ok(Some(some)) => some,
Ok(None) => {
log::warn!("no syntax found for {:?}", path);
self.syntax_system.syntax_set.find_syntax_plain_text()
}
Err(err) => {
log::warn!("failed to determine syntax for {:?}: {:?}", path, err);
self.syntax_system.syntax_set.find_syntax_plain_text()
}
};
// Clear syntax cache
self.syntax_cache.clear();
Ok(())
}
/// Get the default background color
pub fn background_color(&self) -> Color {
if let Some(background) = self.theme.settings.background {
Color::rgba(
background.r,
background.g,
background.b,
background.a,
)
} else {
Color::rgb(0, 0, 0)
}
}
/// Get the default foreground (text) color
pub fn foreground_color(&self) -> Color {
if let Some(foreground) = self.theme.settings.foreground {
Color::rgba(
foreground.r,
foreground.g,
foreground.b,
foreground.a,
)
} else {
Color::rgb(0xFF, 0xFF, 0xFF)
}
}
}
impl<'a> Edit<'a> for SyntaxEditor<'a> {
fn buffer(&self) -> &Buffer<'a> {
self.editor.buffer()
}
fn buffer_mut(&mut self) -> &mut Buffer<'a> {
self.editor.buffer_mut()
}
fn cursor(&self) -> Cursor {
self.editor.cursor()
}
fn select_opt(&self) -> Option<Cursor> {
self.editor.select_opt()
}
fn set_select_opt(&mut self, select_opt: Option<Cursor>) {
self.editor.set_select_opt(select_opt);
}
fn shape_as_needed(&mut self) {
#[cfg(feature = "std")]
let now = std::time::Instant::now();
let buffer = self.editor.buffer_mut();
let mut highlighted = 0;
for line_i in 0..buffer.lines.len() {
let line = &mut buffer.lines[line_i];
if ! line.is_reset() && line_i < self.syntax_cache.len() {
continue;
}
highlighted += 1;
let (mut parse_state, mut highlight_state) = if line_i > 0 && line_i <= self.syntax_cache.len() {
self.syntax_cache[line_i - 1].clone()
} else {
(
ParseState::new(self.syntax),
HighlightState::new(&self.highlighter, ScopeStack::new())
)
};
let ops = parse_state.parse_line(line.text(), &self.syntax_system.syntax_set).expect("failed to parse syntax");
let ranges = RangedHighlightIterator::new(
&mut highlight_state,
&ops,
line.text(),
&self.highlighter,
);
let attrs = line.attrs_list().defaults();
let mut attrs_list = AttrsList::new(attrs);
for (style, _, range) in ranges {
attrs_list.add_span(
range,
attrs
.color(Color::rgba(
style.foreground.r,
style.foreground.g,
style.foreground.b,
style.foreground.a,
))
//TODO: background
.style(if style.font_style.contains(FontStyle::ITALIC) {
Style::Italic
} else {
Style::Normal
})
.weight(if style.font_style.contains(FontStyle::BOLD) {
Weight::BOLD
} else {
Weight::NORMAL
})
//TODO: underline
);
}
// Update line attributes. This operation only resets if the line changes
line.set_attrs_list(attrs_list);
line.set_wrap(Wrap::Word);
//TODO: efficiently do syntax highlighting without having to shape whole buffer
buffer.line_shape(line_i);
let cache_item = (parse_state.clone(), highlight_state.clone());
if line_i < self.syntax_cache.len() {
if self.syntax_cache[line_i] != cache_item {
self.syntax_cache[line_i] = cache_item;
if line_i + 1 < buffer.lines.len() {
buffer.lines[line_i + 1].reset();
}
}
} else {
self.syntax_cache.push(cache_item);
}
}
if highlighted > 0 {
buffer.set_redraw(true);
#[cfg(feature = "std")]
log::debug!("Syntax highlighted {} lines in {:?}", highlighted, now.elapsed());
}
self.editor.shape_as_needed();
}
fn copy_selection(&mut self) -> Option<String> {
self.editor.copy_selection()
}
fn delete_selection(&mut self) -> bool {
self.editor.delete_selection()
}
fn action(&mut self, action: Action) {
self.editor.action(action);
}
/// Draw the editor
#[cfg(feature = "swash")]
fn draw<F>(&self, cache: &mut crate::SwashCache, _color: Color, mut f: F)
where F: FnMut(i32, i32, u32, u32, Color)
{
let size = self.buffer().size();
f(0, 0, size.0 as u32, size.1 as u32, self.background_color());
self.editor.draw(cache, self.foreground_color(), f);
}
}