Add option to run command on bell

Fixes alacritty#1528.

CHANGELOG.md

@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Font fallback on Windows
 - Support for Fontconfig embolden and matrix options
 - Opt-out compilation flag `winpty` to disable WinPTY support
+- Option to run command on bell which can be set in `bell.command`
 
 ### Changed
 

alacritty.yml

@@ -245,31 +245,46 @@
   #
   #indexed_colors: []
 
-# Visual Bell
-#
-# Any time the BEL code is received, Alacritty "rings" the visual bell. Once
-# rung, the terminal background will be set to white and transition back to the
-# default background color. You can control the rate of this transition by
-# setting the `duration` property (represented in milliseconds). You can also
-# configure the transition function by setting the `animation` property.
-#
-# Values for `animation`:
-#   - Ease
-#   - EaseOut
-#   - EaseOutSine
-#   - EaseOutQuad
-#   - EaseOutCubic
-#   - EaseOutQuart
-#   - EaseOutQuint
-#   - EaseOutExpo
-#   - EaseOutCirc
-#   - Linear
-#
-# Specifying a `duration` of `0` will disable the visual bell.
-#visual_bell:
-#  animation: EaseOutExpo
-#  duration: 0
-#  color: '#ffffff'
+# Bell
+#
+# The bell is triggered every time BEL escape sequence is received.
+#bell:
+  # Visual Bell Animation
+  #
+  # Animation effect for flashing the screen when the visual bell is rung.
+  #
+  # Values for `animation`:
+  #   - Ease
+  #   - EaseOut
+  #   - EaseOutSine
+  #   - EaseOutQuad
+  #   - EaseOutCubic
+  #   - EaseOutQuart
+  #   - EaseOutQuint
+  #   - EaseOutExpo
+  #   - EaseOutCirc
+  #   - Linear
+  #animation: EaseOutExpo
+
+  # Duration of the visual bell flash. A `duration` of `0` will disable the
+  # visual bell animation.
+  #duration: 0
+
+  # Visual bell animation color.
+  #color: '#ffffff'
+
+  # Bell Command
+  #
+  # This program is executed whenever the bell is rung.
+  #
+  # When set to `command: None`, bell command will be disabled completely.
+  #
+  # Example:
+  #   command:
+  #     program: notify-send
+  #     args: ["Hello, World!"]
+  #
+  #command: None
 
 # Background opacity
 #

alacritty/src/config/mod.rs

@@ -217,6 +217,13 @@ fn print_deprecation_warnings(config: &Config) {
              the config"
         );
     }
+
+    if config.visual_bell.is_some() {
+        warn!(
+            target: LOG_TARGET_CONFIG,
+            "Config visual_bell has been deprecated; please use bell instead"
+        )
+    }
 }
 
 #[cfg(test)]

alacritty/src/display.rs

@@ -478,7 +478,7 @@ impl Display {
                 0.,
                 size_info.width,
                 size_info.height,
-                config.visual_bell.color,
+                config.bell().color,
                 visual_bell_intensity as f32,
             );
             rects.push(visual_bell_rect);

alacritty/src/event.rs

@@ -573,7 +573,17 @@ impl<N: Notify + OnResize> Processor<N> {
                 },
                 Event::Title(title) => processor.ctx.window.set_title(&title),
                 Event::Wakeup => processor.ctx.terminal.dirty = true,
-                Event::Urgent => {
+                Event::Bell => {
+                    if let Some(command) = processor.ctx.config.bell().command.as_ref() {
+                        let args = command.args().to_vec();
+
+                        match start_daemon(command.program(), &args) {
+                            Ok(_) => debug!("Launched {} with args {:?}", command.program(), args),
+                            Err(_) => {
+                                warn!("Unable to launch {} with args {:?}", command.program(), args)
+                            },
+                        }
+                    }
                     processor.ctx.window.set_urgent(!processor.ctx.terminal.is_focused)
                 },
                 Event::ConfigReload(path) => Self::reload_config(&path, processor),

alacritty_terminal/src/config/bell.rs

@@ -0,0 +1,105 @@
+use std::time::Duration;
+
+use log::error;
+use serde::{Deserialize, Deserializer};
+use serde_yaml::Value;
+
+use crate::config::{failure_default, Program, LOG_TARGET_CONFIG};
+use crate::term::color::Rgb;
+
+const DEFAULT_BELL_COLOR: Rgb = Rgb { r: 255, g: 255, b: 255 };
+
+#[serde(default)]
+#[derive(Deserialize, Clone, Debug, PartialEq, Eq)]
+pub struct BellConfig {
+    /// Visual bell animation function.
+    #[serde(deserialize_with = "failure_default")]
+    pub animation: BellAnimation,
+
+    /// Visual bell duration in milliseconds.
+    #[serde(deserialize_with = "failure_default")]
+    duration: u16,
+
+    // FIXME RGB deserialization always successedes and uses #000000 color. However it should
+    // fallback to a proper color. So it should be reworked either with
+    // https://github.com/alacritty/alacritty/pull/3507 or after that PR will land.
+    /// Visual bell flash color.
+    #[serde(deserialize_with = "failure_default")]
+    pub color: Rgb,
+
+    /// Command to run on bell.
+    #[serde(deserialize_with = "deserialize_command")]
+    pub command: Option<Program>,
+}
+
+impl Default for BellConfig {
+    fn default() -> Self {
+        Self {
+            animation: Default::default(),
+            duration: Default::default(),
+            color: DEFAULT_BELL_COLOR,
+            command: Default::default(),
+        }
+    }
+}
+
+impl BellConfig {
+    /// Visual bell duration in milliseconds.
+    #[inline]
+    pub fn duration(&self) -> Duration {
+        Duration::from_millis(u64::from(self.duration))
+    }
+}
+
+fn deserialize_command<'a, D>(deserializer: D) -> std::result::Result<Option<Program>, D::Error>
+where
+    D: Deserializer<'a>,
+{
+    // Deserialize to generic value.
+    let val = Value::deserialize(deserializer)?;
+
+    // Accept `None` to disable the bell command.
+    if val.as_str().filter(|v| v.to_lowercase() == "none").is_some() {
+        return Ok(None);
+    }
+
+    match <Option<Program>>::deserialize(val) {
+        Ok(command) => Ok(command),
+        Err(err) => {
+            error!(target: LOG_TARGET_CONFIG, "Problem with config: {}; not using anything", err);
+            Ok(None)
+        },
+    }
+}
+
+/// `VisualBellAnimations` are modeled after a subset of CSS transitions and Robert
+/// Penner's Easing Functions.
+#[derive(Clone, Copy, Debug, Deserialize, PartialEq, Eq)]
+pub enum BellAnimation {
+    // CSS animation.
+    Ease,
+    // CSS animation.
+    EaseOut,
+    // Penner animation.
+    EaseOutSine,
+    // Penner animation.
+    EaseOutQuad,
+    // Penner animation.
+    EaseOutCubic,
+    // Penner animation.
+    EaseOutQuart,
+    // Penner animation.
+    EaseOutQuint,
+    // Penner animation.
+    EaseOutExpo,
+    // Penner animation.
+    EaseOutCirc,
+    // Penner animation.
+    Linear,
+}
+
+impl Default for BellAnimation {
+    fn default() -> Self {
+        BellAnimation::EaseOutExpo
+    }
+}

alacritty_terminal/src/config/mod.rs

@@ -6,20 +6,20 @@ use log::error;
 use serde::{Deserialize, Deserializer};
 use serde_yaml::Value;
 
+mod bell;
 mod colors;
 mod debug;
 mod font;
 mod scrolling;
-mod visual_bell;
 mod window;
 
 use crate::ansi::{CursorStyle, NamedColor};
 
+pub use crate::config::bell::{BellAnimation, BellConfig};
 pub use crate::config::colors::Colors;
 pub use crate::config::debug::Debug;
 pub use crate::config::font::{Font, FontDescription};
 pub use crate::config::scrolling::Scrolling;
-pub use crate::config::visual_bell::{VisualBellAnimation, VisualBellConfig};
 pub use crate::config::window::{Decorations, Dimensions, StartupMode, WindowConfig, DEFAULT_NAME};
 use crate::term::color::Rgb;
 
@@ -70,9 +70,9 @@ pub struct Config<T> {
     #[serde(default, deserialize_with = "failure_default")]
     pub config_path: Option<PathBuf>,
 
-    /// Visual bell configuration.
+    /// Bell configuration.
     #[serde(default, deserialize_with = "failure_default")]
-    pub visual_bell: VisualBellConfig,
+    bell: BellConfig,
 
     /// Use dynamic title.
     #[serde(default, deserialize_with = "failure_default")]
@@ -115,6 +115,10 @@ pub struct Config<T> {
     #[serde(skip)]
     pub hold: bool,
 
+    // TODO: DEPRECATED
+    #[serde(default, deserialize_with = "failure_default")]
+    pub visual_bell: Option<BellConfig>,
+
     // TODO: REMOVED
     #[serde(default, deserialize_with = "failure_default")]
     pub tabspaces: Option<usize>,
@@ -201,6 +205,11 @@ impl<T> Config<T> {
     pub fn background_opacity(&self) -> f32 {
         self.background_opacity.0 as f32
     }
+
+    #[inline]
+    pub fn bell(&self) -> &BellConfig {
+        self.visual_bell.as_ref().unwrap_or(&self.bell)
+    }
 }
 
 #[serde(default)]

alacritty_terminal/src/config/visual_bell.rs

@@ -2,47 +2,73 @@ use std::time::Duration;
 
 use serde::Deserialize;
 
-use crate::config::failure_default;
+use crate::config::{failure_default, Program};
 use crate::term::color::Rgb;
 
+const DEFAULT_BELL_COLOR: Rgb = Rgb {r: 255, g: 255, b: 255};
+
 #[serde(default)]
 #[derive(Deserialize, Clone, Debug, PartialEq, Eq)]
-pub struct VisualBellConfig {
+pub struct BellConfig {
     /// Visual bell animation function.
     #[serde(deserialize_with = "failure_default")]
     pub animation: VisualBellAnimation,
 
     /// Visual bell duration in milliseconds.
     #[serde(deserialize_with = "failure_default")]
-    pub duration: u16,
+    duration: u16,
 
     /// Visual bell flash color.
-    #[serde(deserialize_with = "failure_default")]
+    #[serde(deserialize_with = "deserialize_bell_color")]
     pub color: Rgb,
+
+    /// Command to run on bell.
+    pub command: Option<Program>
 }
 
-impl Default for VisualBellConfig {
+impl Default for BellConfig {
     fn default() -> VisualBellConfig {
         VisualBellConfig {
             animation: Default::default(),
             duration: Default::default(),
-            color: default_visual_bell_color(),
+            color: DEFAULT_BELL_COLOR,
+            command: Default::default(),
         }
     }
 }
 
-impl VisualBellConfig {
+impl BellConfig {
     /// Visual bell duration in milliseconds.
     #[inline]
     pub fn duration(&self) -> Duration {
         Duration::from_millis(u64::from(self.duration))
     }
 }
 
+fn deserialize_cursor_thickness<'a, D>(deserializer: D) -> Result<Rgb, D::Error>
+where
+    D: Deserializer<'a>,
+{
+    let value = Value::deserialize(deserializer)?;
+    match Percentage::deserialize(value) {
+        Ok(value) => Ok(value),
+        Err(err) => {
+            error!(
+                target: LOG_TARGET_CONFIG,
+                "Problem with config: {}, using default bell color {}",
+                err,
+                DEFAULT_BELL_COLOR
+            );
+
+            Ok(Percentage::new(DEFAULT_BELL_COLOR))
+        },
+    }
+}
+
 /// `VisualBellAnimations` are modeled after a subset of CSS transitions and Robert
 /// Penner's Easing Functions.
 #[derive(Clone, Copy, Debug, Deserialize, PartialEq, Eq)]
-pub enum VisualBellAnimation {
+pub enum BellAnimation {
     // CSS animation.
     Ease,
     // CSS animation.
@@ -65,12 +91,8 @@ pub enum VisualBellAnimation {
     Linear,
 }
 
-impl Default for VisualBellAnimation {
+impl Default for BellAnimation {
     fn default() -> Self {
-        VisualBellAnimation::EaseOutExpo
+        BellAnimation::EaseOutExpo
     }
 }
-
-fn default_visual_bell_color() -> Rgb {
-    Rgb { r: 255, g: 255, b: 255 }
-}