config: group cursor hiding into CursorHideConfig

Replaces the flat cursor_hide_timeout key with a grouped cursor_hide key
carrying the idle, fullscreen-idle, typing and touch triggers, plus the
pure decision function the compositor's idle timer evaluates on fire.

The fullscreen timeout shortens the global one rather than replacing it,
so an unset fullscreen timeout cannot suppress an enabled global one.

Drafted with Claude (Anthropic); reviewed and tested by the committer.

cosmic-comp-config/src/lib.rs

@@ -3,6 +3,7 @@
 use cosmic_config::{CosmicConfigEntry, cosmic_config_derive::CosmicConfigEntry};
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
+use std::time::Duration;
 
 use crate::input::TouchpadOverride;
 
@@ -106,8 +107,8 @@ pub struct CosmicCompConfig {
     pub edge_snap_threshold: u32,
     pub accessibility_zoom: ZoomConfig,
     pub appearance_settings: AppearanceConfig,
-    /// Hide the cursor after this many seconds of pointer inactivity (None disables)
-    pub cursor_hide_timeout: Option<u32>,
+    /// When the cursor hides itself: idle, fullscreen idle, typing, touch
+    pub cursor_hide: CursorHideConfig,
     /// Briefly magnify the cursor when the pointer is shaken, to help locate it
     pub cursor_shake_to_find: bool,
     pub activation_policy: ActivationPolicy,
@@ -148,7 +149,7 @@ impl Default for CosmicCompConfig {
             edge_snap_threshold: 0,
             accessibility_zoom: ZoomConfig::default(),
             appearance_settings: AppearanceConfig::default(),
-            cursor_hide_timeout: None,
+            cursor_hide: CursorHideConfig::default(),
             cursor_shake_to_find: true,
             activation_policy: ActivationPolicy::default(),
             decoration_preference: DecorationPreference::default(),
@@ -198,6 +199,74 @@ fn default_repeat_delay() -> u32 {
     600
 }
 
+/// What the cursor idle timer should do when it fires.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum HideDecision {
+    /// Nothing applies in this context; drop the timer until the next activity.
+    Drop,
+    /// Hide the cursor now.
+    Hide,
+    /// Not yet — re-arm for this long.
+    RearmAfter(Duration),
+}
+
+/// When the cursor hides itself. Every trigger is revealed by pointer input, so
+/// these differ only in what arms the hide and after how long.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Deserialize, Serialize)]
+pub struct CursorHideConfig {
+    /// Seconds of pointer inactivity before hiding, anywhere. `None` disables.
+    pub idle_timeout: Option<u32>,
+    /// Seconds of pointer inactivity before hiding over a fullscreen window.
+    /// Shortens `idle_timeout` in fullscreen; it never lengthens it.
+    pub fullscreen_idle_timeout: Option<u32>,
+    /// Hide as soon as a key is pressed.
+    pub while_typing: bool,
+    /// Hide on touch input, until the pointer next moves.
+    pub after_touch: bool,
+}
+
+impl CursorHideConfig {
+    /// The shortest timeout that applies right now, if any.
+    pub fn effective_timeout(&self, fullscreen: bool) -> Option<Duration> {
+        let secs = if fullscreen {
+            match (self.idle_timeout, self.fullscreen_idle_timeout) {
+                (Some(a), Some(b)) => Some(a.min(b)),
+                (a, b) => a.or(b),
+            }
+        } else {
+            self.idle_timeout
+        }?;
+        Some(Duration::from_secs(secs as u64))
+    }
+
+    /// What to do when the idle timer fires after `elapsed` without pointer input.
+    pub fn resolve(&self, elapsed: Duration, fullscreen: bool) -> HideDecision {
+        match self.effective_timeout(fullscreen) {
+            None => HideDecision::Drop,
+            Some(timeout) if elapsed >= timeout => HideDecision::Hide,
+            Some(timeout) => HideDecision::RearmAfter(timeout - elapsed),
+        }
+    }
+
+    /// The delay to arm the timer with, before context is known. Callers on the
+    /// input path cannot read fullscreen state without deadlocking, so they arm
+    /// pessimistically and `resolve` corrects it on fire.
+    pub fn shortest_timeout(&self) -> Option<Duration> {
+        self.effective_timeout(true)
+    }
+}
+
+impl Default for CursorHideConfig {
+    fn default() -> Self {
+        CursorHideConfig {
+            idle_timeout: None,
+            fullscreen_idle_timeout: Some(3),
+            while_typing: false,
+            after_touch: true,
+        }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Deserialize, Serialize)]
 pub struct ZoomConfig {
     pub start_on_login: bool,
@@ -263,3 +332,92 @@ pub enum XwaylandDescaling {
     #[default]
     Fractional,
 }
+
+#[cfg(test)]
+mod test {
+    use super::{CursorHideConfig, HideDecision};
+    use std::time::Duration;
+
+    const OFF: CursorHideConfig = CursorHideConfig {
+        idle_timeout: None,
+        fullscreen_idle_timeout: None,
+        while_typing: false,
+        after_touch: false,
+    };
+
+    fn secs(n: u64) -> Duration {
+        Duration::from_secs(n)
+    }
+
+    #[test]
+    fn no_timeout_never_hides() {
+        assert_eq!(OFF.resolve(secs(600), false), HideDecision::Drop);
+        assert_eq!(OFF.resolve(secs(600), true), HideDecision::Drop);
+    }
+
+    #[test]
+    fn global_timeout_applies_everywhere() {
+        let cfg = CursorHideConfig {
+            idle_timeout: Some(10),
+            ..OFF
+        };
+        assert_eq!(
+            cfg.resolve(secs(4), false),
+            HideDecision::RearmAfter(secs(6))
+        );
+        assert_eq!(cfg.resolve(secs(10), false), HideDecision::Hide);
+        // A fullscreen window must not suppress an enabled global timeout.
+        assert_eq!(cfg.resolve(secs(10), true), HideDecision::Hide);
+    }
+
+    #[test]
+    fn fullscreen_timeout_only_applies_in_fullscreen() {
+        let cfg = CursorHideConfig {
+            fullscreen_idle_timeout: Some(3),
+            ..OFF
+        };
+        assert_eq!(cfg.resolve(secs(3), true), HideDecision::Hide);
+        assert_eq!(cfg.resolve(secs(600), false), HideDecision::Drop);
+    }
+
+    #[test]
+    fn fullscreen_shortens_but_never_lengthens() {
+        let short_fs = CursorHideConfig {
+            idle_timeout: Some(10),
+            fullscreen_idle_timeout: Some(3),
+            ..OFF
+        };
+        assert_eq!(short_fs.resolve(secs(3), true), HideDecision::Hide);
+        assert_eq!(
+            short_fs.resolve(secs(3), false),
+            HideDecision::RearmAfter(secs(7))
+        );
+
+        let long_fs = CursorHideConfig {
+            idle_timeout: Some(3),
+            fullscreen_idle_timeout: Some(30),
+            ..OFF
+        };
+        assert_eq!(long_fs.resolve(secs(3), true), HideDecision::Hide);
+
+        // The arming delay is pessimistic: the shortest timeout that could
+        // apply in any context, because arm-time code cannot read the shell.
+        assert_eq!(short_fs.shortest_timeout(), Some(secs(3)));
+        assert_eq!(long_fs.shortest_timeout(), Some(secs(3)));
+        assert_eq!(OFF.shortest_timeout(), None);
+    }
+
+    #[test]
+    fn boundary_is_inclusive() {
+        let cfg = CursorHideConfig {
+            idle_timeout: Some(5),
+            ..OFF
+        };
+        assert_eq!(
+            cfg.resolve(Duration::from_millis(4999), false),
+            HideDecision::RearmAfter(Duration::from_millis(1))
+        );
+        assert_eq!(cfg.resolve(secs(5), false), HideDecision::Hide);
+        assert_eq!(cfg.resolve(secs(6), false), HideDecision::Hide);
+    }
+}