fix: isolate hidden pane render cadence (#2892)

refs #2890

Co-authored-by: akbash-bot <300245827+akbash-bot@users.noreply.github.com>

2 files changed, 35 insertions, 1 deletions

diff --git a/src/app/mod.rs b/src/app/mod.rs
index 2095b99e..501f39f6 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -149,7 +149,10 @@ pub struct App {
     /// Parsed `ui.window_title` plus the hostname resolved when it was applied.
     window_title_template: Option<(crate::config::WindowTitleTemplate, String)>,
     pub(crate) persist_pane_history: bool,
+    /// Last render-loop attempt, including a throttled hidden-only PTY skip.
     pub(crate) last_render_at: Option<Instant>,
+    /// Last attempt that could update a connected presentation surface.
+    pub(crate) last_presentation_at: Option<Instant>,
     pub(crate) input_leases: input::InputLeaseTable,
     pub render_notify: Arc<Notify>,
     pub(crate) render_dirty: Arc<crate::render_signal::RenderSignal>,
@@ -783,6 +786,7 @@ impl App {
             selection_highlight_clear_deadline: None,
             persist_pane_history: config.experimental.pane_history,
             last_render_at: None,
+            last_presentation_at: None,
             input_leases: input::InputLeaseTable::default(),
             api_rx,
             event_hub,
@@ -1133,7 +1137,7 @@ impl App {
                     self.render_dirty.request_generic();
                     self.render_notify.notify_one();
                 }
-                self.last_render_at = Some(now);
+                self.record_render_attempt(now, true);
                 needs_render = false;
                 continue;
             }
diff --git a/src/app/runtime.rs b/src/app/runtime.rs
index d7023727..8367a223 100644
--- a/src/app/runtime.rs
+++ b/src/app/runtime.rs
@@ -534,6 +534,22 @@ impl App {
         }
     }
 
+    pub(crate) fn can_present_now(&self, now: Instant) -> bool {
+        match self.last_presentation_at {
+            Some(last_presentation_at) => {
+                now.duration_since(last_presentation_at) >= MIN_RENDER_INTERVAL
+            }
+            None => true,
+        }
+    }
+
+    pub(crate) fn record_render_attempt(&mut self, now: Instant, presentation: bool) {
+        self.last_render_at = Some(now);
+        if presentation {
+            self.last_presentation_at = Some(now);
+        }
+    }
+
     pub(crate) fn run_auto_update_check(&mut self) {
         if !background_update_check_enabled(self.no_session, self.update_version_check_enabled) {
             self.next_auto_update_check = None;
@@ -658,6 +674,20 @@ mod tests {
     use crate::workspace::Workspace;
 
     #[test]
+    fn hidden_render_attempt_keeps_presentation_cadence_available() {
+        let (mut app, _) = test_app_with_pane();
+        let initial_presentation = Instant::now();
+        app.record_render_attempt(initial_presentation, true);
+
+        let hidden_attempt = initial_presentation + MIN_RENDER_INTERVAL;
+        app.record_render_attempt(hidden_attempt, false);
+        let foreground_echo = hidden_attempt + Duration::from_millis(1);
+
+        assert!(!app.can_render_now(foreground_echo));
+        assert!(app.can_present_now(foreground_echo));
+    }
+
+    #[test]
     fn interrupted_detached_process_wait_keeps_child_for_retry() {
         let interrupted = std::io::Error::new(std::io::ErrorKind::Interrupted, "test interrupt");