teardown scene window when unused

src-tauri/src/puppet/visibility.rs

@@ -0,0 +1,110 @@
+use std::time::{Duration, Instant};
+
+const HIDE_DELAY: Duration = Duration::from_secs(5);
+const SHOW_DELAY: Duration = Duration::from_secs(3);
+
+/// Backend-owned visibility survives destruction of the scene webview.
+pub(super) struct Visibility {
+    pub show_local: bool,
+    pending: Option<(bool, Instant)>,
+}
+
+impl Default for Visibility {
+    fn default() -> Self {
+        Self {
+            show_local: true,
+            pending: None,
+        }
+    }
+}
+
+impl Visibility {
+    pub fn window_open(&self, has_friends: bool) -> bool {
+        self.show_local || has_friends
+    }
+
+    pub fn update(&mut self, hide_when_alone: bool, has_friends: bool, now: Instant) {
+        if !hide_when_alone {
+            self.show_local = true;
+            self.pending = None;
+            return;
+        }
+        if self.show_local == has_friends {
+            self.pending = None;
+            return;
+        }
+        let (target, deadline) = *self.pending.get_or_insert_with(|| {
+            (
+                has_friends,
+                now + if has_friends { SHOW_DELAY } else { HIDE_DELAY },
+            )
+        });
+        if now >= deadline {
+            self.show_local = target;
+            self.pending = None;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn local_puppet_hides_after_five_seconds_and_return_delays_only_local_puppet() {
+        let now = Instant::now();
+        let mut visibility = Visibility::default();
+        visibility.update(true, false, now);
+        visibility.update(true, false, now + HIDE_DELAY - Duration::from_millis(1));
+        assert!(visibility.show_local);
+        visibility.update(true, false, now + HIDE_DELAY);
+        assert!(!visibility.show_local);
+        assert!(!visibility.window_open(false));
+        let returned = now + HIDE_DELAY;
+        visibility.update(true, true, returned);
+        assert!(!visibility.show_local);
+        assert!(visibility.window_open(true));
+        visibility.update(true, true, returned + SHOW_DELAY);
+        assert!(visibility.show_local);
+    }
+
+    #[test]
+    fn reconnect_cancels_hide_and_disconnect_cancels_show() {
+        let now = Instant::now();
+        let mut visibility = Visibility::default();
+        visibility.update(true, false, now);
+        visibility.update(true, true, now + Duration::from_secs(4));
+        visibility.update(true, false, now + Duration::from_secs(5));
+        assert!(visibility.show_local);
+        visibility.update(true, false, now + Duration::from_secs(10));
+        assert!(!visibility.show_local);
+        visibility.update(true, true, now + Duration::from_secs(11));
+        visibility.update(true, false, now + Duration::from_secs(12));
+        visibility.update(true, true, now + Duration::from_secs(14));
+        assert!(!visibility.show_local);
+        visibility.update(true, true, now + Duration::from_secs(17));
+        assert!(visibility.show_local);
+    }
+
+    #[test]
+    fn disabling_setting_restores_local_and_cancels_pending_timer() {
+        let now = Instant::now();
+        let mut visibility = Visibility::default();
+        visibility.update(true, false, now);
+        visibility.update(true, false, now + HIDE_DELAY);
+        visibility.update(false, false, now + HIDE_DELAY);
+        assert!(visibility.show_local);
+        visibility.update(true, false, now + HIDE_DELAY);
+        visibility.update(false, false, now + HIDE_DELAY + Duration::from_secs(1));
+        let restarted = now + HIDE_DELAY + Duration::from_secs(2);
+        visibility.update(true, false, restarted);
+        visibility.update(
+            true,
+            false,
+            restarted + HIDE_DELAY - Duration::from_millis(1),
+        );
+        assert!(visibility.show_local);
+        visibility.update(true, false, restarted + HIDE_DELAY);
+        assert!(!visibility.show_local);
+    }
+}