Allow configuring enhanced keyboard protocol detection

book/src/configuration.md

@@ -62,6 +62,7 @@ Its settings will be merged with the configuration directory `config.toml` and t
 | `color-modes` | Whether to color the mode indicator with different colors depending on the mode itself | `false` |
 | `text-width` | Maximum line length. Used for the `:reflow` command and soft-wrapping if `soft-wrap.wrap-at-text-width` is set | `80` |
 | `workspace-lsp-roots` | Directories relative to the workspace root that are treated as LSP roots. Should only be set in `.helix/config.toml` | `[]` |
+| `enhanced-keyboard-protocol` | Set to `true` to force enabling the enhanced keyboard protocol or `false` to disable. When omitted, the host terminal is queried to detect support | none |
 
 ### `[editor.statusline]` Section
 

helix-tui/src/backend/crossterm.rs

@@ -1,4 +1,8 @@
-use crate::{backend::Backend, buffer::Cell, terminal::Config};
+use crate::{
+ backend::Backend,
+ buffer::Cell,
+ terminal::{Config, FeatureToggle},
+};
 use crossterm::{
  cursor::{Hide, MoveTo, SetCursorStyle, Show},
  event::{
@@ -64,6 +68,7 @@ pub struct CrosstermBackend<W: Write> {
  capabilities: Capabilities,
  supports_keyboard_enhancement_protocol: OnceCell<bool>,
  mouse_capture_enabled: bool,
+ enhanced_keyboard_protocol_enabled: bool,
 }
 
 impl<W> CrosstermBackend<W>
@@ -76,24 +81,31 @@ where
  capabilities: Capabilities::from_env_or_default(config),
  supports_keyboard_enhancement_protocol: OnceCell::new(),
  mouse_capture_enabled: false,
+ enhanced_keyboard_protocol_enabled: false,
  }
  }
 
  #[inline]
- fn supports_keyboard_enhancement_protocol(&self) -> bool {
- *self.supports_keyboard_enhancement_protocol
- .get_or_init(|| {
- use std::time::Instant;
-
- let now = Instant::now();
- let supported = matches!(terminal::supports_keyboard_enhancement(), Ok(true));
- log::debug!(
- "The keyboard enhancement protocol is {}supported in this terminal (checked in {:?})",
- if supported { "" } else { "not " },
- Instant::now().duration_since(now)
- );
- supported
- })
+ fn enable_keyboard_enhancement_protocol(&self, config: Config) -> bool {
+ match config.enable_enhanced_keyboard_protocol {
+ FeatureToggle::Enable => true,
+ FeatureToggle::Disable => false,
+ FeatureToggle::Detect => {
+ *self.supports_keyboard_enhancement_protocol
+ .get_or_init(|| {
+ use std::time::Instant;
+
+ let now = Instant::now();
+ let supported = matches!(terminal::supports_keyboard_enhancement(), Ok(true));
+ log::debug!(
+ "The keyboard enhancement protocol is {}supported in this terminal (checked in {:?})",
+ if supported { "" } else { "not " },
+ Instant::now().duration_since(now)
+ );
+ supported
+ })
+ }
+ }
  }
 }
 
@@ -127,14 +139,15 @@ where
  execute!(self.buffer, EnableMouseCapture)?;
  self.mouse_capture_enabled = true;
  }
- if self.supports_keyboard_enhancement_protocol() {
+ if self.enable_keyboard_enhancement_protocol(config) {
  execute!(
  self.buffer,
  PushKeyboardEnhancementFlags(
  KeyboardEnhancementFlags::DISAMBIGUATE_ESCAPE_CODES
  | KeyboardEnhancementFlags::REPORT_ALTERNATE_KEYS
  )
  )?;
+ self.enhanced_keyboard_protocol_enabled = true;
  }
  Ok(())
  }
@@ -149,6 +162,22 @@ where
  self.mouse_capture_enabled = config.enable_mouse_capture;
  }
 
+ let enable_enhanced_keyboard_protocol = self.enable_keyboard_enhancement_protocol(config);
+ if self.enhanced_keyboard_protocol_enabled != enable_enhanced_keyboard_protocol {
+ if enable_enhanced_keyboard_protocol {
+ execute!(
+ self.buffer,
+ PushKeyboardEnhancementFlags(
+ KeyboardEnhancementFlags::DISAMBIGUATE_ESCAPE_CODES
+ | KeyboardEnhancementFlags::REPORT_ALTERNATE_KEYS
+ )
+ )?;
+ } else {
+ execute!(self.buffer, PopKeyboardEnhancementFlags)?;
+ }
+ self.enhanced_keyboard_protocol_enabled = enable_enhanced_keyboard_protocol;
+ }
+
  Ok(())
  }
 
@@ -158,7 +187,7 @@ where
  if config.enable_mouse_capture {
  execute!(self.buffer, DisableMouseCapture)?;
  }
- if self.supports_keyboard_enhancement_protocol() {
+ if self.enable_keyboard_enhancement_protocol(config) {
  execute!(self.buffer, PopKeyboardEnhancementFlags)?;
  }
  execute!(

helix-tui/src/terminal.rs

@@ -17,15 +17,30 @@ pub struct Viewport {
  resize_behavior: ResizeBehavior,
 }
 
+#[derive(Debug)]
+pub enum FeatureToggle {
+ Enable,
+ Disable,
+ Detect,
+}
+
 #[derive(Debug)]
 pub struct Config {
  pub enable_mouse_capture: bool,
+ pub enable_enhanced_keyboard_protocol: FeatureToggle,
 }
 
 impl From<EditorConfig> for Config {
  fn from(config: EditorConfig) -> Self {
+ let enable_enhanced_keyboard_protocol = match config.enhanced_keyboard_protocol {
+ Some(true) => FeatureToggle::Enable,
+ Some(false) => FeatureToggle::Disable,
+ None => FeatureToggle::Detect,
+ };
+
  Self {
  enable_mouse_capture: config.mouse,
+ enable_enhanced_keyboard_protocol,
  }
  }
 }

helix-view/src/editor.rs

@@ -284,6 +284,9 @@ pub struct Config {
  pub soft_wrap: SoftWrap,
  /// Workspace specific lsp ceiling dirs
  pub workspace_lsp_roots: Vec<PathBuf>,
+ /// Whether to force enabling or disabling support for the enhanced keyboard protocol.
+ /// Set to `None` to automatically detect support by querying the host terminal.
+ pub enhanced_keyboard_protocol: Option<bool>,
 }
 
 #[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
@@ -759,6 +762,7 @@ impl Default for Config {
  text_width: 80,
  completion_replace: false,
  workspace_lsp_roots: Vec::new(),
+ enhanced_keyboard_protocol: None,
  }
  }
 }