Add `window.blur` config option

Fixes #972.

CHANGELOG.md

@@ -24,6 +24,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Support startup notify protocol to raise initial window on Wayland/X11
 - Debug option `prefer_egl` to prioritize EGL over other display APIs
 - Inline vi-mode search using `f`/`F`/`t`/`T`
+- `window.blur` config option to request blur for transparent windows
 
 ### Changed
 

Cargo.lock

@@ -2386,9 +2386,9 @@ checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
 
 [[package]]
 name = "winit"
-version = "0.29.2"
+version = "0.29.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b829f75d02fe1e225b97c91a04c326900147a50234d1141a1cbe215ce8798c11"
+checksum = "161598019a9da35ab6c34dc46cd13546cba9dbf9816475d4dd9a639455016563"
 dependencies = [
  "ahash",
  "android-activity",

alacritty/Cargo.toml

@@ -41,7 +41,7 @@ serde_json = "1"
 serde_yaml = "0.9.25"
 toml = "0.8.2"
 unicode-width = "0.1"
-winit = { version = "0.29.2", default-features = false, features = ["rwh_05", "serde"] }
+winit = { version = "0.29.3", default-features = false, features = ["rwh_05", "serde"] }
 
 [build-dependencies]
 gl_generator = "0.14.0"

alacritty/src/config/window.rs

@@ -48,6 +48,9 @@ pub struct WindowConfig {
     /// Background opacity from 0.0 to 1.0.
     pub opacity: Percentage,
 
+    /// Request blur behind the window.
+    pub blur: bool,
+
     /// Controls which `Option` key should be treated as `Alt`.
     #[cfg(target_os = "macos")]
     option_as_alt: OptionAsAlt,
@@ -66,17 +69,18 @@ impl Default for WindowConfig {
     fn default() -> Self {
         Self {
             dynamic_title: true,
+            blur: Default::default(),
+            embed: Default::default(),
+            padding: Default::default(),
+            opacity: Default::default(),
             position: Default::default(),
+            identity: Default::default(),
+            dimensions: Default::default(),
             decorations: Default::default(),
             startup_mode: Default::default(),
-            embed: Default::default(),
-            decorations_theme_variant: Default::default(),
             dynamic_padding: Default::default(),
-            identity: Identity::default(),
-            opacity: Default::default(),
-            padding: Default::default(),
-            dimensions: Default::default(),
             resize_increments: Default::default(),
+            decorations_theme_variant: Default::default(),
             #[cfg(target_os = "macos")]
             option_as_alt: Default::default(),
         }

alacritty/src/display/window.rs

@@ -167,6 +167,7 @@ impl Window {
             .with_theme(config.window.decorations_theme_variant)
             .with_visible(false)
             .with_transparent(true)
+            .with_blur(config.window.blur)
             .with_maximized(config.window.maximized())
             .with_fullscreen(config.window.fullscreen())
             .build(event_loop)?;
@@ -343,6 +344,10 @@ impl Window {
         self.window.set_transparent(transparent);
     }
 
+    pub fn set_blur(&self, blur: bool) {
+        self.window.set_blur(blur);
+    }
+
     pub fn set_maximized(&self, maximized: bool) {
         self.window.set_maximized(maximized);
     }

alacritty/src/window_context.rs

@@ -345,8 +345,9 @@ impl WindowContext {
         #[cfg(target_os = "macos")]
         self.display.window.set_option_as_alt(self.config.window.option_as_alt());
 
-        // Change opacity state.
+        // Change opacity and blur state.
         self.display.window.set_transparent(!opaque);
+        self.display.window.set_blur(self.config.window.blur);
 
         // Update hint keys.
         self.display.hint_state.update_alphabet(self.config.hints.alphabet());

extra/man/alacritty.5.scd

@@ -133,6 +133,12 @@ This section documents the *[window]* table of the configuration file.
 
 	Default: _1.0_
 
+*blur* <boolean> _(works on macOS/KDE Wayland)_
+
+	Request compositor to blur content behind transparent windows.
+
+	Default: _false_
+
 *startup_mode* "Windowed" | "Maximized" | "Fullscreen" | "SimpleFullscreen"
 
 	Startup mode (changes require restart)