From 4c36c067b06e3bba24e0b2bd0f40f259ca6c8b41 Mon Sep 17 00:00:00 2001
From: Pascal Kuthe <pascal.kuthe@semimod.de>
Date: Fri, 7 Oct 2022 00:09:55 +0200
Subject: [PATCH] avoid visual artificats on terminal emulators that do not
support underline colors
---
helix-tui/src/backend/crossterm.rs | 77 ++++++++++++++++++++++++++----
1 file changed, 68 insertions(+), 9 deletions(-)
diff --git a/helix-tui/src/backend/crossterm.rs b/helix-tui/src/backend/crossterm.rs
index 4d8c6650..7b3b0817 100644
--- a/helix-tui/src/backend/crossterm.rs
+++ b/helix-tui/src/backend/crossterm.rs
@@ -4,13 +4,16 @@ use crossterm::{
execute, queue,
style::{
Attribute as CAttribute, Color as CColor, Print, SetAttribute, SetBackgroundColor,
- SetForegroundColor, SetUnderlineColor,
+ SetForegroundColor,
},
terminal::{self, Clear, ClearType},
+ Command,
};
use helix_view::graphics::{Color, CursorKind, Modifier, Rect, UnderlineStyle};
-use std::io::{self, Write};
-
+use std::{
+ fmt,
+ io::{self, Write},
+};
fn vte_version() -> Option<usize> {
std::env::var("VTE_VERSION").ok()?.parse().ok()
}
@@ -108,18 +111,19 @@ where
map_error(queue!(self.buffer, SetBackgroundColor(color)))?;
bg = cell.bg;
}
- if cell.underline_color != underline_color {
- let color = CColor::from(cell.underline_color);
- map_error(queue!(self.buffer, SetUnderlineColor(color)))?;
- underline_color = cell.underline_color;
- }
let mut new_underline_style = cell.underline_style;
if !self.capabilities.has_extended_underlines {
match new_underline_style {
- UnderlineStyle::Reset => (),
+ UnderlineStyle::Reset | UnderlineStyle::Line => (),
_ => new_underline_style = UnderlineStyle::Line,
}
+
+ if cell.underline_color != underline_color {
+ let color = CColor::from(cell.underline_color);
+ map_error(queue!(self.buffer, SetUnderlineColor(color)))?;
+ underline_color = cell.underline_color;
+ }
}
if new_underline_style != underline_style {
@@ -244,3 +248,58 @@ impl ModifierDiff {
Ok(())
}
}
+
+/// Crossterm uses semicolon as a seperator for colors
+/// this is actually not spec compliant (altough commonly supported)
+/// However the correct approach is to use colons as a seperator.
+/// This usually doesn't make a difference for emulators that do support colored underlines.
+/// However terminals that do not support colored underlines will ignore underlines colors with colons
+/// while escape sequences with semicolons are always processed which leads to weird visual artifacts.
+/// See [this nvim issue](https://github.com/neovim/neovim/issues/9270) for details
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct SetUnderlineColor(pub CColor);
+
+impl Command for SetUnderlineColor {
+ fn write_ansi(&self, f: &mut impl fmt::Write) -> fmt::Result {
+ let color = self.0;
+
+ if color == CColor::Reset {
+ write!(f, "\x1b[59m")?;
+ return Ok(());
+ }
+ f.write_str("\x1b[58:")?;
+
+ let res = match color {
+ CColor::Black => f.write_str("5:0"),
+ CColor::DarkGrey => f.write_str("5:8"),
+ CColor::Red => f.write_str("5:9"),
+ CColor::DarkRed => f.write_str("5:1"),
+ CColor::Green => f.write_str("5:10"),
+ CColor::DarkGreen => f.write_str("5:2"),
+ CColor::Yellow => f.write_str("5:11"),
+ CColor::DarkYellow => f.write_str("5:3"),
+ CColor::Blue => f.write_str("5:12"),
+ CColor::DarkBlue => f.write_str("5:4"),
+ CColor::Magenta => f.write_str("5:13"),
+ CColor::DarkMagenta => f.write_str("5:5"),
+ CColor::Cyan => f.write_str("5:14"),
+ CColor::DarkCyan => f.write_str("5:6"),
+ CColor::White => f.write_str("5:15"),
+ CColor::Grey => f.write_str("5:7"),
+ CColor::Rgb { r, g, b } => write!(f, "2::{}:{}:{}", r, g, b),
+ CColor::AnsiValue(val) => write!(f, "5:{}", val),
+ _ => Ok(()),
+ };
+ res?;
+ write!(f, "m")?;
+ Ok(())
+ }
+
+ #[cfg(windows)]
+ fn execute_winapi(&self) -> crossterm::Result<()> {
+ Err(std::io::Error::new(
+ std::io::ErrorKind::Other,
+ "SetUnderlineColor not supported by winapi.",
+ ))
+ }
+}