diff options
Diffstat (limited to 'highlighter/src/lib.rs')
| -rw-r--r-- | highlighter/src/lib.rs | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/highlighter/src/lib.rs b/highlighter/src/lib.rs new file mode 100644 index 00000000..63f21fc0 --- /dev/null +++ b/highlighter/src/lib.rs @@ -0,0 +1,245 @@ +use iced_core as core; + +use crate::core::text::highlighter::{self, Format}; +use crate::core::{Color, Font}; + +use once_cell::sync::Lazy; +use std::ops::Range; +use syntect::highlighting; +use syntect::parsing; + +static SYNTAXES: Lazy<parsing::SyntaxSet> = + Lazy::new(parsing::SyntaxSet::load_defaults_nonewlines); + +static THEMES: Lazy<highlighting::ThemeSet> = + Lazy::new(highlighting::ThemeSet::load_defaults); + +const LINES_PER_SNAPSHOT: usize = 50; + +pub struct Highlighter { + syntax: &'static parsing::SyntaxReference, + highlighter: highlighting::Highlighter<'static>, + caches: Vec<(parsing::ParseState, parsing::ScopeStack)>, + current_line: usize, +} + +impl highlighter::Highlighter for Highlighter { + type Settings = Settings; + type Highlight = Highlight; + + type Iterator<'a> = + Box<dyn Iterator<Item = (Range<usize>, Self::Highlight)> + 'a>; + + fn new(settings: &Self::Settings) -> Self { + let syntax = SYNTAXES + .find_syntax_by_token(&settings.extension) + .unwrap_or_else(|| SYNTAXES.find_syntax_plain_text()); + + let highlighter = highlighting::Highlighter::new( + &THEMES.themes[settings.theme.key()], + ); + + let parser = parsing::ParseState::new(syntax); + let stack = parsing::ScopeStack::new(); + + Highlighter { + syntax, + highlighter, + caches: vec![(parser, stack)], + current_line: 0, + } + } + + fn update(&mut self, new_settings: &Self::Settings) { + self.syntax = SYNTAXES + .find_syntax_by_token(&new_settings.extension) + .unwrap_or_else(|| SYNTAXES.find_syntax_plain_text()); + + self.highlighter = highlighting::Highlighter::new( + &THEMES.themes[new_settings.theme.key()], + ); + + // Restart the highlighter + self.change_line(0); + } + + fn change_line(&mut self, line: usize) { + let snapshot = line / LINES_PER_SNAPSHOT; + + if snapshot <= self.caches.len() { + self.caches.truncate(snapshot); + self.current_line = snapshot * LINES_PER_SNAPSHOT; + } else { + self.caches.truncate(1); + self.current_line = 0; + } + + let (parser, stack) = + self.caches.last().cloned().unwrap_or_else(|| { + ( + parsing::ParseState::new(self.syntax), + parsing::ScopeStack::new(), + ) + }); + + self.caches.push((parser, stack)); + } + + fn highlight_line(&mut self, line: &str) -> Self::Iterator<'_> { + if self.current_line / LINES_PER_SNAPSHOT >= self.caches.len() { + let (parser, stack) = + self.caches.last().expect("Caches must not be empty"); + + self.caches.push((parser.clone(), stack.clone())); + } + + self.current_line += 1; + + let (parser, stack) = + self.caches.last_mut().expect("Caches must not be empty"); + + let ops = parser.parse_line(line, &SYNTAXES).unwrap_or_default(); + + let highlighter = &self.highlighter; + + Box::new( + ScopeRangeIterator { + ops, + line_length: line.len(), + index: 0, + last_str_index: 0, + } + .filter_map(move |(range, scope)| { + let _ = stack.apply(&scope); + + if range.is_empty() { + None + } else { + Some(( + range, + Highlight( + highlighter.style_mod_for_stack(&stack.scopes), + ), + )) + } + }), + ) + } + + fn current_line(&self) -> usize { + self.current_line + } +} + +#[derive(Debug, Clone, PartialEq)] +pub struct Settings { + pub theme: Theme, + pub extension: String, +} + +pub struct Highlight(highlighting::StyleModifier); + +impl Highlight { + pub fn color(&self) -> Option<Color> { + self.0.foreground.map(|color| { + Color::from_rgba8(color.r, color.g, color.b, color.a as f32 / 255.0) + }) + } + + pub fn font(&self) -> Option<Font> { + None + } + + pub fn to_format(&self) -> Format<Font> { + Format { + color: self.color(), + font: self.font(), + } + } +} + +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +pub enum Theme { + SolarizedDark, + Base16Mocha, + Base16Ocean, + Base16Eighties, + InspiredGitHub, +} + +impl Theme { + pub const ALL: &'static [Self] = &[ + Self::SolarizedDark, + Self::Base16Mocha, + Self::Base16Ocean, + Self::Base16Eighties, + Self::InspiredGitHub, + ]; + + pub fn is_dark(self) -> bool { + match self { + Self::SolarizedDark + | Self::Base16Mocha + | Self::Base16Ocean + | Self::Base16Eighties => true, + Self::InspiredGitHub => false, + } + } + + fn key(self) -> &'static str { + match self { + Theme::SolarizedDark => "Solarized (dark)", + Theme::Base16Mocha => "base16-mocha.dark", + Theme::Base16Ocean => "base16-ocean.dark", + Theme::Base16Eighties => "base16-eighties.dark", + Theme::InspiredGitHub => "InspiredGitHub", + } + } +} + +impl std::fmt::Display for Theme { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match self { + Theme::SolarizedDark => write!(f, "Solarized Dark"), + Theme::Base16Mocha => write!(f, "Mocha"), + Theme::Base16Ocean => write!(f, "Ocean"), + Theme::Base16Eighties => write!(f, "Eighties"), + Theme::InspiredGitHub => write!(f, "Inspired GitHub"), + } + } +} + +pub struct ScopeRangeIterator { + ops: Vec<(usize, parsing::ScopeStackOp)>, + line_length: usize, + index: usize, + last_str_index: usize, +} + +impl Iterator for ScopeRangeIterator { + type Item = (std::ops::Range<usize>, parsing::ScopeStackOp); + + fn next(&mut self) -> Option<Self::Item> { + if self.index > self.ops.len() { + return None; + } + + let next_str_i = if self.index == self.ops.len() { + self.line_length + } else { + self.ops[self.index].0 + }; + + let range = self.last_str_index..next_str_i; + self.last_str_index = next_str_i; + + let op = if self.index == 0 { + parsing::ScopeStackOp::Noop + } else { + self.ops[self.index - 1].1.clone() + }; + + self.index += 1; + Some((range, op)) + } +} |