Implement xray background effect

niri-config/src/appearance.rs

@@ -1006,6 +1006,29 @@ where
     }
 }
 
+#[derive(knuffel::Decode, Debug, Default, Clone, Copy, PartialEq)]
+pub struct BackgroundEffectRule {
+    #[knuffel(child, unwrap(argument))]
+    pub xray: Option<bool>,
+}
+
+/// Resolved background effect rule.
+#[derive(Debug, Default, Clone, Copy, PartialEq)]
+pub struct BackgroundEffect {
+    /// Whether to render with xray effect (see through).
+    ///
+    /// - `None`: xray if any background effect is active
+    /// - `Some(false)`: no xray
+    /// - `Some(true)`: xray even if no other background effect is active
+    pub xray: Option<bool>,
+}
+
+impl MergeWith<BackgroundEffectRule> for BackgroundEffect {
+    fn merge_with(&mut self, part: &BackgroundEffectRule) {
+        merge_clone_opt!((self, part), xray);
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use insta::{assert_debug_snapshot, assert_snapshot};

niri-config/src/layer_rule.rs

@@ -1,4 +1,4 @@
-use crate::appearance::{BlockOutFrom, CornerRadius, ShadowRule};
+use crate::appearance::{BackgroundEffectRule, BlockOutFrom, CornerRadius, ShadowRule};
 use crate::utils::RegexEq;
 
 #[derive(knuffel::Decode, Debug, Default, Clone, PartialEq)]
@@ -20,6 +20,8 @@ pub struct LayerRule {
     pub place_within_backdrop: Option<bool>,
     #[knuffel(child, unwrap(argument))]
     pub baba_is_float: Option<bool>,
+    #[knuffel(child, default)]
+    pub background_effect: BackgroundEffectRule,
 }
 
 #[derive(knuffel::Decode, Debug, Default, Clone, PartialEq)]

niri-config/src/lib.rs

@@ -1845,6 +1845,9 @@ mod tests {
                     ),
                     scroll_factor: None,
                     tiled_state: None,
+                    background_effect: BackgroundEffectRule {
+                        xray: None,
+                    },
                 },
             ],
             layer_rules: [
@@ -1880,6 +1883,9 @@ mod tests {
                     geometry_corner_radius: None,
                     place_within_backdrop: None,
                     baba_is_float: None,
+                    background_effect: BackgroundEffectRule {
+                        xray: None,
+                    },
                 },
             ],
             binds: Binds(

niri-config/src/window_rule.rs

@@ -1,6 +1,8 @@
 use niri_ipc::ColumnDisplay;
 
-use crate::appearance::{BlockOutFrom, BorderRule, CornerRadius, ShadowRule, TabIndicatorRule};
+use crate::appearance::{
+    BackgroundEffectRule, BlockOutFrom, BorderRule, CornerRadius, ShadowRule, TabIndicatorRule,
+};
 use crate::layout::DefaultPresetSize;
 use crate::utils::RegexEq;
 use crate::FloatOrInt;
@@ -72,6 +74,8 @@ pub struct WindowRule {
     pub scroll_factor: Option<FloatOrInt<0, 100>>,
     #[knuffel(child, unwrap(argument))]
     pub tiled_state: Option<bool>,
+    #[knuffel(child, default)]
+    pub background_effect: BackgroundEffectRule,
 }
 
 #[derive(knuffel::Decode, Debug, Default, Clone, PartialEq)]