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helix/helix-view/src/theme.rs

578 lines
18 KiB
Rust

use std::{
collections::{HashMap, HashSet},
path::{Path, PathBuf},
str,
};
use anyhow::{anyhow, Result};
use helix_core::hashmap;
use helix_loader::merge_toml_values;
use log::warn;
use once_cell::sync::Lazy;
use serde::{Deserialize, Deserializer};
use toml::{map::Map, Value};
use crate::graphics::UnderlineStyle;
pub use crate::graphics::{Color, Modifier, Style};
pub static DEFAULT_THEME_DATA: Lazy<Value> = Lazy::new(|| {
let bytes = include_bytes!("../../theme.toml");
toml::from_str(str::from_utf8(bytes).unwrap()).expect("Failed to parse base default theme")
});
pub static BASE16_DEFAULT_THEME_DATA: Lazy<Value> = Lazy::new(|| {
let bytes = include_bytes!("../../base16_theme.toml");
toml::from_str(str::from_utf8(bytes).unwrap()).expect("Failed to parse base 16 default theme")
});
pub static DEFAULT_THEME: Lazy<Theme> = Lazy::new(|| Theme {
name: "default".into(),
..Theme::from(DEFAULT_THEME_DATA.clone())
});
pub static BASE16_DEFAULT_THEME: Lazy<Theme> = Lazy::new(|| Theme {
name: "base16_default".into(),
..Theme::from(BASE16_DEFAULT_THEME_DATA.clone())
});
#[derive(Clone, Debug)]
pub struct Loader {
/// Theme directories to search from highest to lowest priority
theme_dirs: Vec<PathBuf>,
}
impl Loader {
/// Creates a new loader that can load themes from multiple directories.
///
/// The provided directories should be ordered from highest to lowest priority.
/// The directories will have their "themes" subdirectory searched.
pub fn new(dirs: &[PathBuf]) -> Self {
Self {
theme_dirs: dirs.iter().map(|p| p.join("themes")).collect(),
}
}
/// Loads a theme searching directories in priority order.
pub fn load(&self, name: &str) -> Result<Theme> {
if name == "default" {
return Ok(self.default());
}
if name == "base16_default" {
return Ok(self.base16_default());
}
let mut visited_paths = HashSet::new();
let theme = self.load_theme(name, &mut visited_paths).map(Theme::from)?;
Ok(Theme {
name: name.into(),
..theme
})
}
/// Recursively load a theme, merging with any inherited parent themes.
///
/// The paths that have been visited in the inheritance hierarchy are tracked
/// to detect and avoid cycling.
///
/// It is possible for one file to inherit from another file with the same name
/// so long as the second file is in a themes directory with lower priority.
/// However, it is not recommended that users do this as it will make tracing
/// errors more difficult.
fn load_theme(&self, name: &str, visited_paths: &mut HashSet<PathBuf>) -> Result<Value> {
let path = self.path(name, visited_paths)?;
let theme_toml = self.load_toml(path)?;
let inherits = theme_toml.get("inherits");
let theme_toml = if let Some(parent_theme_name) = inherits {
let parent_theme_name = parent_theme_name.as_str().ok_or_else(|| {
anyhow!(
"Theme: expected 'inherits' to be a string: {}",
parent_theme_name
)
})?;
let parent_theme_toml = match parent_theme_name {
// load default themes's toml from const.
"default" => DEFAULT_THEME_DATA.clone(),
"base16_default" => BASE16_DEFAULT_THEME_DATA.clone(),
_ => self.load_theme(parent_theme_name, visited_paths)?,
};
self.merge_themes(parent_theme_toml, theme_toml)
} else {
theme_toml
};
Ok(theme_toml)
}
pub fn read_names(path: &Path) -> Vec<String> {
std::fs::read_dir(path)
.map(|entries| {
entries
.filter_map(|entry| {
let entry = entry.ok()?;
let path = entry.path();
(path.extension()? == "toml")
.then(|| path.file_stem().unwrap().to_string_lossy().into_owned())
})
.collect()
})
.unwrap_or_default()
}
// merge one theme into the parent theme
fn merge_themes(&self, parent_theme_toml: Value, theme_toml: Value) -> Value {
let parent_palette = parent_theme_toml.get("palette");
let palette = theme_toml.get("palette");
// handle the table separately since it needs a `merge_depth` of 2
// this would conflict with the rest of the theme merge strategy
let palette_values = match (parent_palette, palette) {
(Some(parent_palette), Some(palette)) => {
merge_toml_values(parent_palette.clone(), palette.clone(), 2)
}
(Some(parent_palette), None) => parent_palette.clone(),
(None, Some(palette)) => palette.clone(),
(None, None) => Map::new().into(),
};
// add the palette correctly as nested table
let mut palette = Map::new();
palette.insert(String::from("palette"), palette_values);
// merge the theme into the parent theme
let theme = merge_toml_values(parent_theme_toml, theme_toml, 1);
// merge the before specially handled palette into the theme
merge_toml_values(theme, palette.into(), 1)
}
// Loads the theme data as `toml::Value`
fn load_toml(&self, path: PathBuf) -> Result<Value> {
let data = std::fs::read_to_string(path)?;
let value = toml::from_str(&data)?;
Ok(value)
}
/// Returns the path to the theme with the given name
///
/// Ignores paths already visited and follows directory priority order.
fn path(&self, name: &str, visited_paths: &mut HashSet<PathBuf>) -> Result<PathBuf> {
let filename = format!("{}.toml", name);
let mut cycle_found = false; // track if there was a path, but it was in a cycle
self.theme_dirs
.iter()
.find_map(|dir| {
let path = dir.join(&filename);
if !path.exists() {
None
} else if visited_paths.contains(&path) {
// Avoiding cycle, continuing to look in lower priority directories
cycle_found = true;
None
} else {
visited_paths.insert(path.clone());
Some(path)
}
})
.ok_or_else(|| {
if cycle_found {
anyhow!("Theme: cycle found in inheriting: {}", name)
} else {
anyhow!("Theme: file not found for: {}", name)
}
})
}
pub fn default_theme(&self, true_color: bool) -> Theme {
if true_color {
self.default()
} else {
self.base16_default()
}
}
/// Returns the default theme
pub fn default(&self) -> Theme {
DEFAULT_THEME.clone()
}
/// Returns the alternative 16-color default theme
pub fn base16_default(&self) -> Theme {
BASE16_DEFAULT_THEME.clone()
}
}
#[derive(Clone, Debug, Default)]
pub struct Theme {
name: String,
// UI styles are stored in a HashMap
styles: HashMap<String, Style>,
// tree-sitter highlight styles are stored in a Vec to optimize lookups
scopes: Vec<String>,
highlights: Vec<Style>,
}
impl From<Value> for Theme {
fn from(value: Value) -> Self {
if let Value::Table(table) = value {
let (styles, scopes, highlights) = build_theme_values(table);
Self {
styles,
scopes,
highlights,
..Default::default()
}
} else {
warn!("Expected theme TOML value to be a table, found {:?}", value);
Default::default()
}
}
}
impl<'de> Deserialize<'de> for Theme {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let values = Map::<String, Value>::deserialize(deserializer)?;
let (styles, scopes, highlights) = build_theme_values(values);
Ok(Self {
styles,
scopes,
highlights,
..Default::default()
})
}
}
fn build_theme_values(
mut values: Map<String, Value>,
) -> (HashMap<String, Style>, Vec<String>, Vec<Style>) {
let mut styles = HashMap::new();
let mut scopes = Vec::new();
let mut highlights = Vec::new();
// TODO: alert user of parsing failures in editor
let palette = values
.remove("palette")
.map(|value| {
ThemePalette::try_from(value).unwrap_or_else(|err| {
warn!("{}", err);
ThemePalette::default()
})
})
.unwrap_or_default();
// remove inherits from value to prevent errors
let _ = values.remove("inherits");
styles.reserve(values.len());
scopes.reserve(values.len());
highlights.reserve(values.len());
for (name, style_value) in values {
let mut style = Style::default();
if let Err(err) = palette.parse_style(&mut style, style_value) {
warn!("{}", err);
}
// these are used both as UI and as highlights
styles.insert(name.clone(), style);
scopes.push(name);
highlights.push(style);
}
(styles, scopes, highlights)
}
impl Theme {
#[inline]
pub fn highlight(&self, index: usize) -> Style {
self.highlights[index]
}
#[inline]
pub fn scope(&self, index: usize) -> &str {
&self.scopes[index]
}
pub fn name(&self) -> &str {
&self.name
}
pub fn get(&self, scope: &str) -> Style {
self.try_get(scope).unwrap_or_default()
}
/// Get the style of a scope, falling back to dot separated broader
/// scopes. For example if `ui.text.focus` is not defined in the theme,
/// `ui.text` is tried and then `ui` is tried.
pub fn try_get(&self, scope: &str) -> Option<Style> {
std::iter::successors(Some(scope), |s| Some(s.rsplit_once('.')?.0))
.find_map(|s| self.styles.get(s).copied())
}
/// Get the style of a scope, without falling back to dot separated broader
/// scopes. For example if `ui.text.focus` is not defined in the theme, it
/// will return `None`, even if `ui.text` is.
pub fn try_get_exact(&self, scope: &str) -> Option<Style> {
self.styles.get(scope).copied()
}
#[inline]
pub fn scopes(&self) -> &[String] {
&self.scopes
}
pub fn find_scope_index_exact(&self, scope: &str) -> Option<usize> {
self.scopes().iter().position(|s| s == scope)
}
pub fn find_scope_index(&self, mut scope: &str) -> Option<usize> {
loop {
if let Some(highlight) = self.find_scope_index_exact(scope) {
return Some(highlight);
}
if let Some(new_end) = scope.rfind('.') {
scope = &scope[..new_end];
} else {
return None;
}
}
}
pub fn is_16_color(&self) -> bool {
self.styles.iter().all(|(_, style)| {
[style.fg, style.bg]
.into_iter()
.all(|color| !matches!(color, Some(Color::Rgb(..))))
})
}
}
struct ThemePalette {
palette: HashMap<String, Color>,
}
impl Default for ThemePalette {
fn default() -> Self {
Self {
palette: hashmap! {
"default".to_string() => Color::Reset,
"black".to_string() => Color::Black,
"red".to_string() => Color::Red,
"green".to_string() => Color::Green,
"yellow".to_string() => Color::Yellow,
"blue".to_string() => Color::Blue,
"magenta".to_string() => Color::Magenta,
"cyan".to_string() => Color::Cyan,
"gray".to_string() => Color::Gray,
"light-red".to_string() => Color::LightRed,
"light-green".to_string() => Color::LightGreen,
"light-yellow".to_string() => Color::LightYellow,
"light-blue".to_string() => Color::LightBlue,
"light-magenta".to_string() => Color::LightMagenta,
"light-cyan".to_string() => Color::LightCyan,
"light-gray".to_string() => Color::LightGray,
"white".to_string() => Color::White,
},
}
}
}
impl ThemePalette {
pub fn new(palette: HashMap<String, Color>) -> Self {
let ThemePalette {
palette: mut default,
} = ThemePalette::default();
default.extend(palette);
Self { palette: default }
}
pub fn string_to_rgb(s: &str) -> Result<Color, String> {
if s.starts_with('#') {
Self::hex_string_to_rgb(s)
} else {
Self::ansi_string_to_rgb(s)
}
}
fn ansi_string_to_rgb(s: &str) -> Result<Color, String> {
if let Ok(index) = s.parse::<u8>() {
return Ok(Color::Indexed(index));
}
Err(format!("Theme: malformed ANSI: {}", s))
}
fn hex_string_to_rgb(s: &str) -> Result<Color, String> {
if s.len() >= 7 {
if let (Ok(red), Ok(green), Ok(blue)) = (
u8::from_str_radix(&s[1..3], 16),
u8::from_str_radix(&s[3..5], 16),
u8::from_str_radix(&s[5..7], 16),
) {
return Ok(Color::Rgb(red, green, blue));
}
}
Err(format!("Theme: malformed hexcode: {}", s))
}
fn parse_value_as_str(value: &Value) -> Result<&str, String> {
value
.as_str()
.ok_or(format!("Theme: unrecognized value: {}", value))
}
pub fn parse_color(&self, value: Value) -> Result<Color, String> {
let value = Self::parse_value_as_str(&value)?;
self.palette
.get(value)
.copied()
.ok_or("")
.or_else(|_| Self::string_to_rgb(value))
}
pub fn parse_modifier(value: &Value) -> Result<Modifier, String> {
value
.as_str()
.and_then(|s| s.parse().ok())
.ok_or(format!("Theme: invalid modifier: {}", value))
}
pub fn parse_underline_style(value: &Value) -> Result<UnderlineStyle, String> {
value
.as_str()
.and_then(|s| s.parse().ok())
.ok_or(format!("Theme: invalid underline style: {}", value))
}
pub fn parse_style(&self, style: &mut Style, value: Value) -> Result<(), String> {
if let Value::Table(entries) = value {
for (name, mut value) in entries {
match name.as_str() {
"fg" => *style = style.fg(self.parse_color(value)?),
"bg" => *style = style.bg(self.parse_color(value)?),
"underline" => {
let table = value
.as_table_mut()
.ok_or("Theme: underline must be table")?;
if let Some(value) = table.remove("color") {
*style = style.underline_color(self.parse_color(value)?);
}
if let Some(value) = table.remove("style") {
*style = style.underline_style(Self::parse_underline_style(&value)?);
}
if let Some(attr) = table.keys().next() {
return Err(format!("Theme: invalid underline attribute: {attr}"));
}
}
"modifiers" => {
let modifiers = value
.as_array()
.ok_or("Theme: modifiers should be an array")?;
for modifier in modifiers {
if modifier
.as_str()
.map_or(false, |modifier| modifier == "underlined")
{
*style = style.underline_style(UnderlineStyle::Line);
} else {
*style = style.add_modifier(Self::parse_modifier(modifier)?);
}
}
}
_ => return Err(format!("Theme: invalid style attribute: {}", name)),
}
}
} else {
*style = style.fg(self.parse_color(value)?);
}
Ok(())
}
}
impl TryFrom<Value> for ThemePalette {
type Error = String;
fn try_from(value: Value) -> Result<Self, Self::Error> {
let map = match value {
Value::Table(entries) => entries,
_ => return Ok(Self::default()),
};
let mut palette = HashMap::with_capacity(map.len());
for (name, value) in map {
let value = Self::parse_value_as_str(&value)?;
let color = Self::string_to_rgb(value)?;
palette.insert(name, color);
}
Ok(Self::new(palette))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_parse_style_string() {
let fg = Value::String("#ffffff".to_string());
let mut style = Style::default();
let palette = ThemePalette::default();
palette.parse_style(&mut style, fg).unwrap();
assert_eq!(style, Style::default().fg(Color::Rgb(255, 255, 255)));
}
#[test]
fn test_palette() {
use helix_core::hashmap;
let fg = Value::String("my_color".to_string());
let mut style = Style::default();
let palette =
ThemePalette::new(hashmap! { "my_color".to_string() => Color::Rgb(255, 255, 255) });
palette.parse_style(&mut style, fg).unwrap();
assert_eq!(style, Style::default().fg(Color::Rgb(255, 255, 255)));
}
#[test]
fn test_parse_style_table() {
let table = toml::toml! {
"keyword" = {
fg = "#ffffff",
bg = "#000000",
modifiers = ["bold"],
}
};
let mut style = Style::default();
let palette = ThemePalette::default();
for (_name, value) in table {
palette.parse_style(&mut style, value).unwrap();
}
assert_eq!(
style,
Style::default()
.fg(Color::Rgb(255, 255, 255))
.bg(Color::Rgb(0, 0, 0))
.add_modifier(Modifier::BOLD)
);
}
}