Unify window presentation and frame-driven shell motion

Share window geometry across overview, resize snapshots and retained closes. Advance close handoffs and group retained rendering by stacking position.

Drive shell motion from surface frames, reuse settled widget content, and synchronize notification materials with each card's fade. Replace physical config keys with duration and bounce, and update documentation and regression coverage.

shell/ferese-shell/src/motion.rs

@@ -1,3 +1,6 @@
+mod frames;
+pub(crate) use frames::frame_driven;
+
 use cosmic::iced::advanced::{Clipboard, Layout, Renderer as _, Shell, Widget, layout, mouse, renderer, widget};
 use cosmic::iced::{Event, Length, Rectangle, Size, Transformation, Vector};
 use cosmic::{Element, Theme};
@@ -79,11 +82,7 @@ impl PopupMotion {
             value.snap();
             return value;
         }
-        let spring = self
-            .settings
-            .spring
-            .resolve(SpringConfig::default())
-            .expect("validated motion settings");
+        let spring = self.settings.spring_config().expect("validated motion settings");
         value.advance(
             now.saturating_duration_since(started).mul_f64(self.settings.speed),
             SpringConfig {
@@ -105,8 +104,17 @@ impl PopupMotion {
     pub(crate) fn closing(&self) -> bool {
         self.value.target == 0.0
     }
+    pub(crate) fn revision(&self) -> Option<std::time::Instant> {
+        self.started
+    }
+    pub(crate) fn frame_active(&self, now: std::time::Instant) -> bool {
+        self.started.is_some() && self.animating_at(now)
+    }
     pub(crate) fn animating(&self) -> bool {
-        let value = self.sample(std::time::Instant::now());
+        self.animating_at(std::time::Instant::now())
+    }
+    pub(crate) fn animating_at(&self, now: std::time::Instant) -> bool {
+        let value = self.sample(now);
         value.current != value.target || value.velocity != 0.0
     }
 
@@ -238,11 +246,14 @@ impl<M> Widget<M, Theme, cosmic::Renderer> for Hover<'_, M> {
         shell: &mut Shell<'_, M>,
         viewport: &Rectangle,
     ) {
-        let now = std::time::Instant::now();
+        let now = match event {
+            Event::Window(cosmic::iced::window::Event::RedrawRequested(at)) => *at,
+            _ => std::time::Instant::now(),
+        };
         let hovered = cursor.is_over(layout.bounds()) && cursor.is_over(*viewport);
         let state = tree.state.downcast_mut::<HoverState>();
         if state.advance(if hovered { 1.0 } else { 0.0 }, now, self.duration) {
-            shell.request_redraw_at(now + std::time::Duration::from_millis(16));
+            shell.request_redraw();
         }
         self.progress.set(state.current);
         self.content.as_widget_mut().update(
@@ -494,10 +505,12 @@ impl widget::Operation for CollectRegions {
 #[cfg(test)]
 mod tests {
     #[test]
-    fn zero_damping_with_crossing_clamp_finishes_popup_close() {
+    fn duration_bounce_spring_finishes_popup_close() {
         let settings = super::Settings {
             spring: ferese_animation::SpringSettings {
-                damping: Some(0.0),
+                duration_ms: Some(240.0),
+                bounce: 0.3,
+                overshoot: true,
                 ..Default::default()
             },
             ..Default::default()