Merge pull request #4061 from pascalkuthe/undercurl-modifier

Support different kinds of underline rendering (updated)

3 files changed, 116 insertions, 8 deletions

diff --git a/helix-view/src/graphics.rs b/helix-view/src/graphics.rs
index fb3c8b3f..4374a537 100644
--- a/helix-view/src/graphics.rs
+++ b/helix-view/src/graphics.rs
@@ -315,6 +315,44 @@ impl From<Color> for crossterm::style::Color {
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum UnderlineStyle {
+    Reset,
+    Line,
+    Curl,
+    Dotted,
+    Dashed,
+    DoubleLine,
+}
+
+impl FromStr for UnderlineStyle {
+    type Err = &'static str;
+
+    fn from_str(modifier: &str) -> Result<Self, Self::Err> {
+        match modifier {
+            "line" => Ok(Self::Line),
+            "curl" => Ok(Self::Curl),
+            "dotted" => Ok(Self::Dotted),
+            "dashed" => Ok(Self::Dashed),
+            "double_line" => Ok(Self::DoubleLine),
+            _ => Err("Invalid underline style"),
+        }
+    }
+}
+
+impl From<UnderlineStyle> for crossterm::style::Attribute {
+    fn from(style: UnderlineStyle) -> Self {
+        match style {
+            UnderlineStyle::Line => crossterm::style::Attribute::Underlined,
+            UnderlineStyle::Curl => crossterm::style::Attribute::Undercurled,
+            UnderlineStyle::Dotted => crossterm::style::Attribute::Underdotted,
+            UnderlineStyle::Dashed => crossterm::style::Attribute::Underdashed,
+            UnderlineStyle::DoubleLine => crossterm::style::Attribute::DoubleUnderlined,
+            UnderlineStyle::Reset => crossterm::style::Attribute::NoUnderline,
+        }
+    }
+}
+
 bitflags! {
     /// Modifier changes the way a piece of text is displayed.
     ///
@@ -332,7 +370,6 @@ bitflags! {
         const BOLD              = 0b0000_0000_0001;
         const DIM               = 0b0000_0000_0010;
         const ITALIC            = 0b0000_0000_0100;
-        const UNDERLINED        = 0b0000_0000_1000;
         const SLOW_BLINK        = 0b0000_0001_0000;
         const RAPID_BLINK       = 0b0000_0010_0000;
         const REVERSED          = 0b0000_0100_0000;
@@ -349,7 +386,6 @@ impl FromStr for Modifier {
             "bold" => Ok(Self::BOLD),
             "dim" => Ok(Self::DIM),
             "italic" => Ok(Self::ITALIC),
-            "underlined" => Ok(Self::UNDERLINED),
             "slow_blink" => Ok(Self::SLOW_BLINK),
             "rapid_blink" => Ok(Self::RAPID_BLINK),
             "reversed" => Ok(Self::REVERSED),
@@ -375,7 +411,7 @@ impl FromStr for Modifier {
 /// just S3.
 ///
 /// ```rust
-/// # use helix_view::graphics::{Rect, Color, Modifier, Style};
+/// # use helix_view::graphics::{Rect, Color, UnderlineStyle, Modifier, Style};
 /// # use helix_tui::buffer::Buffer;
 /// let styles = [
 ///     Style::default().fg(Color::Blue).add_modifier(Modifier::BOLD | Modifier::ITALIC),
@@ -391,6 +427,8 @@ impl FromStr for Modifier {
 ///         fg: Some(Color::Yellow),
 ///         bg: Some(Color::Red),
 ///         add_modifier: Modifier::BOLD,
+///         underline_color: Some(Color::Reset),
+///         underline_style: Some(UnderlineStyle::Reset),
 ///         sub_modifier: Modifier::empty(),
 ///     },
 ///     buffer[(0, 0)].style(),
@@ -401,7 +439,7 @@ impl FromStr for Modifier {
 /// reset all properties until that point use [`Style::reset`].
 ///
 /// ```
-/// # use helix_view::graphics::{Rect, Color, Modifier, Style};
+/// # use helix_view::graphics::{Rect, Color, UnderlineStyle, Modifier, Style};
 /// # use helix_tui::buffer::Buffer;
 /// let styles = [
 ///     Style::default().fg(Color::Blue).add_modifier(Modifier::BOLD | Modifier::ITALIC),
@@ -415,6 +453,8 @@ impl FromStr for Modifier {
 ///     Style {
 ///         fg: Some(Color::Yellow),
 ///         bg: Some(Color::Reset),
+///         underline_color: Some(Color::Reset),
+///         underline_style: Some(UnderlineStyle::Reset),
 ///         add_modifier: Modifier::empty(),
 ///         sub_modifier: Modifier::empty(),
 ///     },
@@ -426,6 +466,8 @@ impl FromStr for Modifier {
 pub struct Style {
     pub fg: Option<Color>,
     pub bg: Option<Color>,
+    pub underline_color: Option<Color>,
+    pub underline_style: Option<UnderlineStyle>,
     pub add_modifier: Modifier,
     pub sub_modifier: Modifier,
 }
@@ -435,6 +477,8 @@ impl Default for Style {
         Style {
             fg: None,
             bg: None,
+            underline_color: None,
+            underline_style: None,
             add_modifier: Modifier::empty(),
             sub_modifier: Modifier::empty(),
         }
@@ -447,6 +491,8 @@ impl Style {
         Style {
             fg: Some(Color::Reset),
             bg: Some(Color::Reset),
+            underline_color: None,
+            underline_style: None,
             add_modifier: Modifier::empty(),
             sub_modifier: Modifier::all(),
         }
@@ -482,6 +528,36 @@ impl Style {
         self
     }
 
+    /// Changes the underline color.
+    ///
+    /// ## Examples
+    ///
+    /// ```rust
+    /// # use helix_view::graphics::{Color, Style};
+    /// let style = Style::default().underline_color(Color::Blue);
+    /// let diff = Style::default().underline_color(Color::Red);
+    /// assert_eq!(style.patch(diff), Style::default().underline_color(Color::Red));
+    /// ```
+    pub fn underline_color(mut self, color: Color) -> Style {
+        self.underline_color = Some(color);
+        self
+    }
+
+    /// Changes the underline style.
+    ///
+    /// ## Examples
+    ///
+    /// ```rust
+    /// # use helix_view::graphics::{UnderlineStyle, Style};
+    /// let style = Style::default().underline_style(UnderlineStyle::Line);
+    /// let diff = Style::default().underline_style(UnderlineStyle::Curl);
+    /// assert_eq!(style.patch(diff), Style::default().underline_style(UnderlineStyle::Curl));
+    /// ```
+    pub fn underline_style(mut self, style: UnderlineStyle) -> Style {
+        self.underline_style = Some(style);
+        self
+    }
+
     /// Changes the text emphasis.
     ///
     /// When applied, it adds the given modifier to the `Style` modifiers.
@@ -538,6 +614,8 @@ impl Style {
     pub fn patch(mut self, other: Style) -> Style {
         self.fg = other.fg.or(self.fg);
         self.bg = other.bg.or(self.bg);
+        self.underline_color = other.underline_color.or(self.underline_color);
+        self.underline_style = other.underline_style.or(self.underline_style);
 
         self.add_modifier.remove(other.sub_modifier);
         self.add_modifier.insert(other.add_modifier);
diff --git a/helix-view/src/gutter.rs b/helix-view/src/gutter.rs
index ab0e2986..2c207d27 100644
--- a/helix-view/src/gutter.rs
+++ b/helix-view/src/gutter.rs
@@ -1,7 +1,7 @@
 use std::fmt::Write;
 
 use crate::{
-    graphics::{Color, Modifier, Style},
+    graphics::{Color, Style, UnderlineStyle},
     Document, Editor, Theme, View,
 };
 
@@ -147,7 +147,7 @@ pub fn breakpoints<'doc>(
             .find(|breakpoint| breakpoint.line == line)?;
 
         let mut style = if breakpoint.condition.is_some() && breakpoint.log_message.is_some() {
-            error.add_modifier(Modifier::UNDERLINED)
+            error.underline_style(UnderlineStyle::Line)
         } else if breakpoint.condition.is_some() {
             error
         } else if breakpoint.log_message.is_some() {
diff --git a/helix-view/src/theme.rs b/helix-view/src/theme.rs
index 8a1f8b7e..302844b7 100644
--- a/helix-view/src/theme.rs
+++ b/helix-view/src/theme.rs
@@ -11,6 +11,7 @@ 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: Lazy<Theme> = Lazy::new(|| {
@@ -378,19 +379,48 @@ impl ThemePalette {
             .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, value) in entries {
+            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 {
-                            *style = style.add_modifier(Self::parse_modifier(modifier)?);
+                            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)),