From d3011992a76e83e12f74402c2ade616cdc7f1497 Mon Sep 17 00:00:00 2001
From: Héctor Ramón Jiménez <hector@hecrj.dev>
Date: Sun, 17 Sep 2023 19:03:58 +0200
Subject: Implement basic syntax highlighting with `syntect` in `editor`
example
---
core/src/text/highlighter.rs | 2 +-
examples/editor/Cargo.toml | 4 +-
examples/editor/src/main.rs | 168 ++++++++++++++++++++++++++++++++++++++++++-
graphics/src/text/editor.rs | 25 ++++++-
widget/src/text_editor.rs | 18 +++++
5 files changed, 211 insertions(+), 6 deletions(-)
diff --git a/core/src/text/highlighter.rs b/core/src/text/highlighter.rs
index 1f9ac840..a929826f 100644
--- a/core/src/text/highlighter.rs
+++ b/core/src/text/highlighter.rs
@@ -3,7 +3,7 @@ use crate::Color;
use std::hash::Hash;
use std::ops::Range;
-pub trait Highlighter: Clone + 'static {
+pub trait Highlighter: 'static {
type Settings: Hash;
type Highlight;
diff --git a/examples/editor/Cargo.toml b/examples/editor/Cargo.toml
index 528cf23c..930ee592 100644
--- a/examples/editor/Cargo.toml
+++ b/examples/editor/Cargo.toml
@@ -7,4 +7,6 @@ publish = false
[dependencies]
iced.workspace = true
-iced.features = ["debug"]
\ No newline at end of file
+iced.features = ["advanced", "debug"]
+
+syntect = "5.1"
\ No newline at end of file
diff --git a/examples/editor/src/main.rs b/examples/editor/src/main.rs
index 11819c69..a72feebc 100644
--- a/examples/editor/src/main.rs
+++ b/examples/editor/src/main.rs
@@ -1,6 +1,8 @@
use iced::widget::{container, text_editor};
use iced::{Element, Font, Sandbox, Settings, Theme};
+use highlighter::Highlighter;
+
pub fn main() -> iced::Result {
Editor::run(Settings::default())
}
@@ -41,7 +43,10 @@ impl Sandbox for Editor {
container(
text_editor(&self.content)
.on_edit(Message::Edit)
- .font(Font::with_name("Hasklug Nerd Font Mono")),
+ .font(Font::with_name("Hasklug Nerd Font Mono"))
+ .highlight::<Highlighter>(highlighter::Settings {
+ token: String::from("md"),
+ }),
)
.padding(20)
.into()
@@ -51,3 +56,164 @@ impl Sandbox for Editor {
Theme::Dark
}
}
+
+mod highlighter {
+ use iced::advanced::text::highlighter;
+ use iced::widget::text_editor;
+ use iced::{Color, Font, Theme};
+
+ use std::ops::Range;
+ use syntect::highlighting;
+ use syntect::parsing;
+
+ #[derive(Debug, Clone, Hash)]
+ pub struct Settings {
+ pub token: String,
+ }
+
+ pub struct Highlight(highlighting::StyleModifier);
+
+ impl text_editor::Highlight for Highlight {
+ fn format(&self, _theme: &Theme) -> highlighter::Format<Font> {
+ highlighter::Format {
+ color: self.0.foreground.map(|color| {
+ Color::from_rgba8(
+ color.r,
+ color.g,
+ color.b,
+ color.a as f32 / 255.0,
+ )
+ }),
+ font: None,
+ }
+ }
+ }
+
+ pub struct Highlighter {
+ syntaxes: parsing::SyntaxSet,
+ parser: parsing::ParseState,
+ stack: parsing::ScopeStack,
+ theme: highlighting::Theme,
+ token: String,
+ 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 syntaxes = parsing::SyntaxSet::load_defaults_nonewlines();
+
+ let syntax = syntaxes
+ .find_syntax_by_token(&settings.token)
+ .unwrap_or_else(|| syntaxes.find_syntax_plain_text());
+
+ let parser = parsing::ParseState::new(&syntax);
+ let stack = parsing::ScopeStack::new();
+
+ let theme = highlighting::ThemeSet::load_defaults()
+ .themes
+ .remove("base16-mocha.dark")
+ .unwrap();
+
+ Highlighter {
+ syntaxes,
+ parser,
+ stack,
+ theme,
+ token: settings.token.clone(),
+ current_line: 0,
+ }
+ }
+
+ fn change_line(&mut self, _line: usize) {
+ // TODO: Caching
+ let syntax = self
+ .syntaxes
+ .find_syntax_by_token(&self.token)
+ .unwrap_or_else(|| self.syntaxes.find_syntax_plain_text());
+
+ self.parser = parsing::ParseState::new(&syntax);
+ self.stack = parsing::ScopeStack::new();
+ self.current_line = 0;
+ }
+
+ fn highlight_line(&mut self, line: &str) -> Self::Iterator<'_> {
+ self.current_line += 1;
+
+ let ops = self
+ .parser
+ .parse_line(line, &self.syntaxes)
+ .unwrap_or_default();
+
+ Box::new(
+ ScopeRangeIterator {
+ ops,
+ line_length: line.len(),
+ index: 0,
+ last_str_index: 0,
+ }
+ .filter_map(move |(range, scope)| {
+ let highlighter =
+ highlighting::Highlighter::new(&self.theme);
+ let _ = self.stack.apply(&scope);
+
+ if range.is_empty() {
+ None
+ } else {
+ Some((
+ range,
+ Highlight(
+ highlighter
+ .style_mod_for_stack(&self.stack.scopes),
+ ),
+ ))
+ }
+ }),
+ )
+ }
+
+ fn current_line(&self) -> usize {
+ self.current_line
+ }
+ }
+
+ 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))
+ }
+ }
+}
diff --git a/graphics/src/text/editor.rs b/graphics/src/text/editor.rs
index 901b4295..58fcc3dc 100644
--- a/graphics/src/text/editor.rs
+++ b/graphics/src/text/editor.rs
@@ -447,17 +447,26 @@ impl editor::Editor for Editor {
text::font_system().write().expect("Write font system");
if font_system.version() != internal.version {
+ log::trace!("Updating `FontSystem` of `Editor`...");
+
for line in internal.editor.buffer_mut().lines.iter_mut() {
line.reset();
}
}
if new_font != internal.font {
+ log::trace!("Updating font of `Editor`...");
+
for line in internal.editor.buffer_mut().lines.iter_mut() {
let _ = line.set_attrs_list(cosmic_text::AttrsList::new(
text::to_attributes(new_font),
));
}
+
+ internal.font = new_font;
+ internal.topmost_line_changed = Some(0);
+
+ internal.editor.shape_as_needed(font_system.raw());
}
let metrics = internal.editor.buffer().metrics();
@@ -466,6 +475,8 @@ impl editor::Editor for Editor {
if new_size.0 != metrics.font_size
|| new_line_height.0 != metrics.line_height
{
+ log::trace!("Updating `Metrics` of `Editor`...");
+
internal.editor.buffer_mut().set_metrics(
font_system.raw(),
cosmic_text::Metrics::new(new_size.0, new_line_height.0),
@@ -473,6 +484,8 @@ impl editor::Editor for Editor {
}
if new_bounds != internal.bounds {
+ log::trace!("Updating size of `Editor`...");
+
internal.editor.buffer_mut().set_size(
font_system.raw(),
new_bounds.width,
@@ -484,6 +497,10 @@ impl editor::Editor for Editor {
if let Some(topmost_line_changed) = internal.topmost_line_changed.take()
{
+ log::trace!(
+ "Notifying highlighter of line change: {topmost_line_changed}"
+ );
+
new_highlighter.change_line(topmost_line_changed);
}
@@ -497,10 +514,12 @@ impl editor::Editor for Editor {
format_highlight: impl Fn(&H::Highlight) -> highlighter::Format<Self::Font>,
) {
let internal = self.internal();
+ let buffer = internal.editor.buffer();
- let scroll = internal.editor.buffer().scroll();
- let visible_lines = internal.editor.buffer().visible_lines();
- let last_visible_line = (scroll + visible_lines - 1) as usize;
+ let scroll = buffer.scroll();
+ let visible_lines = buffer.visible_lines();
+ let last_visible_line =
+ ((scroll + visible_lines) as usize).min(buffer.lines.len()) - 1;
let current_line = highlighter.current_line();
diff --git a/widget/src/text_editor.rs b/widget/src/text_editor.rs
index b17e1156..03adbb59 100644
--- a/widget/src/text_editor.rs
+++ b/widget/src/text_editor.rs
@@ -81,6 +81,24 @@ where
self.padding = padding.into();
self
}
+
+ pub fn highlight<H: text::Highlighter>(
+ self,
+ settings: H::Settings,
+ ) -> TextEditor<'a, H, Message, Renderer> {
+ TextEditor {
+ content: self.content,
+ font: self.font,
+ text_size: self.text_size,
+ line_height: self.line_height,
+ width: self.width,
+ height: self.height,
+ padding: self.padding,
+ style: self.style,
+ on_edit: self.on_edit,
+ highlighter_settings: settings,
+ }
+ }
}
pub struct Content<R = crate::Renderer>(RefCell<Internal<R>>)
--
cgit