From 3ad7d543ca17963f0839b1a6cd8abacdb5c60cf7 Mon Sep 17 00:00:00 2001
From: A-Walrus <ofek.r.guy@gmail.com>
Date: Thu, 11 Aug 2022 14:10:29 +0300
Subject: [PATCH] Add separate color for underlines

---
 helix-tui/src/backend/crossterm.rs |  8 +++++++-
 helix-tui/src/buffer.rs            |  7 +++++++
 helix-view/src/graphics.rs         | 19 +++++++++++++++++++
 helix-view/src/theme.rs            |  1 +
 runtime/themes/dark_plus.toml      |  3 ++-
 5 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/helix-tui/src/backend/crossterm.rs b/helix-tui/src/backend/crossterm.rs
index 252036f38..fe9da9198 100644
--- a/helix-tui/src/backend/crossterm.rs
+++ b/helix-tui/src/backend/crossterm.rs
@@ -4,7 +4,7 @@ use crossterm::{
     execute, queue,
     style::{
         Attribute as CAttribute, Color as CColor, Print, SetAttribute, SetBackgroundColor,
-        SetForegroundColor,
+        SetForegroundColor, SetUnderlineColor,
     },
     terminal::{self, Clear, ClearType},
 };
@@ -47,6 +47,7 @@ where
     {
         let mut fg = Color::Reset;
         let mut bg = Color::Reset;
+        let mut underline = Color::Reset;
         let mut modifier = Modifier::empty();
         let mut last_pos: Option<(u16, u16)> = None;
         for (x, y, cell) in content {
@@ -73,6 +74,11 @@ where
                 map_error(queue!(self.buffer, SetBackgroundColor(color)))?;
                 bg = cell.bg;
             }
+            if cell.underline != underline {
+                let color = CColor::from(cell.underline);
+                map_error(queue!(self.buffer, SetUnderlineColor(color)))?;
+                underline = cell.underline;
+            }
 
             map_error(queue!(self.buffer, Print(&cell.symbol)))?;
         }
diff --git a/helix-tui/src/buffer.rs b/helix-tui/src/buffer.rs
index 21c53aadf..14f3ecafa 100644
--- a/helix-tui/src/buffer.rs
+++ b/helix-tui/src/buffer.rs
@@ -11,6 +11,7 @@ pub struct Cell {
     pub symbol: String,
     pub fg: Color,
     pub bg: Color,
+    pub underline: Color,
     pub modifier: Modifier,
 }
 
@@ -44,6 +45,9 @@ impl Cell {
         if let Some(c) = style.bg {
             self.bg = c;
         }
+        if let Some(c) = style.underline {
+            self.underline = c;
+        }
         self.modifier.insert(style.add_modifier);
         self.modifier.remove(style.sub_modifier);
         self
@@ -53,6 +57,7 @@ impl Cell {
         Style::default()
             .fg(self.fg)
             .bg(self.bg)
+            .underline(self.bg)
             .add_modifier(self.modifier)
     }
 
@@ -61,6 +66,7 @@ impl Cell {
         self.symbol.push(' ');
         self.fg = Color::Reset;
         self.bg = Color::Reset;
+        self.underline = Color::Reset;
         self.modifier = Modifier::empty();
     }
 }
@@ -71,6 +77,7 @@ impl Default for Cell {
             symbol: " ".into(),
             fg: Color::Reset,
             bg: Color::Reset,
+            underline: Color::Reset,
             modifier: Modifier::empty(),
         }
     }
diff --git a/helix-view/src/graphics.rs b/helix-view/src/graphics.rs
index 15492119b..c995f60c9 100644
--- a/helix-view/src/graphics.rs
+++ b/helix-view/src/graphics.rs
@@ -440,6 +440,7 @@ impl FromStr for Modifier {
 pub struct Style {
     pub fg: Option<Color>,
     pub bg: Option<Color>,
+    pub underline: Option<Color>,
     pub add_modifier: Modifier,
     pub sub_modifier: Modifier,
 }
@@ -449,6 +450,7 @@ impl Default for Style {
         Style {
             fg: None,
             bg: None,
+            underline: None,
             add_modifier: Modifier::empty(),
             sub_modifier: Modifier::empty(),
         }
@@ -461,6 +463,7 @@ impl Style {
         Style {
             fg: Some(Color::Reset),
             bg: Some(Color::Reset),
+            underline: Some(Color::Reset),
             add_modifier: Modifier::empty(),
             sub_modifier: Modifier::all(),
         }
@@ -496,6 +499,21 @@ impl Style {
         self
     }
 
+    /// Changes the underline color.
+    ///
+    /// ## Examples
+    ///
+    /// ```rust
+    /// # use helix_view::graphics::{Color, Style};
+    /// let style = Style::default().underline(Color::Blue);
+    /// let diff = Style::default().underline(Color::Red);
+    /// assert_eq!(style.patch(diff), Style::default().underline(Color::Red));
+    /// ```
+    pub fn underline(mut self, color: Color) -> Style {
+        self.underline = Some(color);
+        self
+    }
+
     /// Changes the text emphasis.
     ///
     /// When applied, it adds the given modifier to the `Style` modifiers.
@@ -552,6 +570,7 @@ 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 = other.underline.or(self.underline);
 
         self.add_modifier.remove(other.sub_modifier);
         self.add_modifier.insert(other.add_modifier);
diff --git a/helix-view/src/theme.rs b/helix-view/src/theme.rs
index fa5fa7028..5ce1b2c57 100644
--- a/helix-view/src/theme.rs
+++ b/helix-view/src/theme.rs
@@ -269,6 +269,7 @@ impl ThemePalette {
                 match name.as_str() {
                     "fg" => *style = style.fg(self.parse_color(value)?),
                     "bg" => *style = style.bg(self.parse_color(value)?),
+                    "underline" => *style = style.underline(self.parse_color(value)?),
                     "modifiers" => {
                         let modifiers = value
                             .as_array()
diff --git a/runtime/themes/dark_plus.toml b/runtime/themes/dark_plus.toml
index f99da4fbf..d1a5756ef 100644
--- a/runtime/themes/dark_plus.toml
+++ b/runtime/themes/dark_plus.toml
@@ -92,7 +92,8 @@
 "info" = { fg = "light_blue" }
 "hint" = { fg = "light_gray3" }
 
-diagnostic = { modifiers = ["underlined"] }
+"diagnostic.error" = {underline = "red", modifiers = ["undercurled"] }
+"diagnostic" = {underline = "gold", modifiers = ["undercurled"] }
 
 [palette]
 white = "#ffffff"