fix(theme): refresh host appearance on focus (#2417)

* fix(theme): refresh host appearance on focus

refs #2416

* fix(input): preserve split appearance replies

refs #2416

* fix(input): retain fragmented appearance reports

refs #2416

---------

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

6 files changed, 203 insertions, 6 deletions

diff --git a/src/app/runtime.rs b/src/app/runtime.rs
index e05b9599..49420381 100644
--- a/src/app/runtime.rs
+++ b/src/app/runtime.rs
@@ -233,6 +233,8 @@ impl App {
                 changes_view
             }
             crate::raw_input::RawInputEvent::OuterFocusGained => {
+                #[cfg(not(windows))]
+                self.query_host_terminal_appearance();
                 self.send_outer_focus_event(crate::ghostty::FocusEvent::Gained);
                 if self.state.redraw_on_focus_gained {
                     self.request_repaint();
diff --git a/src/app/theme_sync.rs b/src/app/theme_sync.rs
index 32716ced..6bf06685 100644
--- a/src/app/theme_sync.rs
+++ b/src/app/theme_sync.rs
@@ -1,6 +1,15 @@
 use super::App;
 
 impl App {
+    #[cfg(not(windows))]
+    pub(super) fn query_host_terminal_appearance(&self) {
+        use std::io::Write;
+
+        let _ = std::io::stdout()
+            .write_all(crate::terminal_theme::HOST_COLOR_SCHEME_QUERY_SEQUENCE.as_bytes());
+        let _ = std::io::stdout().flush();
+    }
+
     pub(super) fn query_host_terminal_theme(&self) {
         use std::io::Write;
 
diff --git a/src/client/input.rs b/src/client/input.rs
index 9e0d300e..4dc26eae 100644
--- a/src/client/input.rs
+++ b/src/client/input.rs
@@ -77,6 +77,7 @@ fn unix_stdin_reader_loop(
     if host_color_query_sent {
         framer.host_color_query_sent();
         framer.enable_host_color_scheme_change_tracking();
+        framer.enable_host_appearance_query_on_focus();
     }
     if host_cell_size_query_sent {
         framer.host_cell_size_query_sent();
diff --git a/src/client/mod.rs b/src/client/mod.rs
index fd92d188..b153dd93 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -1442,6 +1442,9 @@ async fn run_client_loop(
                     ) {
                         state.request_repaint();
                     }
+                    if crate::raw_input::events_require_host_terminal_appearance_query(&events) {
+                        query_host_terminal_appearance();
+                    }
                     if crate::raw_input::events_require_host_terminal_theme_query(&events) {
                         query_host_terminal_theme();
                     }
@@ -2281,6 +2284,17 @@ fn resize_poll_loop(
 // Logging
 // ---------------------------------------------------------------------------
 
+#[cfg(any(not(windows), test))]
+fn query_host_terminal_appearance() {
+    let _ = write_host_terminal_appearance_query(io::stdout());
+}
+
+#[cfg(any(not(windows), test))]
+fn write_host_terminal_appearance_query(mut writer: impl io::Write) -> io::Result<()> {
+    writer.write_all(crate::terminal_theme::HOST_COLOR_SCHEME_QUERY_SEQUENCE.as_bytes())?;
+    writer.flush()
+}
+
 /// Initialize logging for the client process.
 fn query_host_terminal_theme() {
     let _ = write_host_terminal_theme_query(io::stdout());
@@ -2673,6 +2687,13 @@ mod tests {
     }
 
     #[test]
+    fn write_host_terminal_appearance_query_emits_mode_2031_query() {
+        let mut output = Vec::new();
+        write_host_terminal_appearance_query(&mut output).unwrap();
+        assert_eq!(output, b"\x1b[?996n");
+    }
+
+    #[test]
     fn write_host_terminal_theme_query_emits_osc_queries() {
         let mut output = Vec::new();
         write_host_terminal_theme_query(&mut output).unwrap();
@@ -2680,6 +2701,10 @@ mod tests {
             output,
             crate::terminal_theme::host_terminal_theme_query_sequence().as_bytes()
         );
+        assert!(!output
+            .windows(crate::terminal_theme::HOST_COLOR_SCHEME_QUERY_SEQUENCE.len())
+            .any(|window| window
+                == crate::terminal_theme::HOST_COLOR_SCHEME_QUERY_SEQUENCE.as_bytes()));
     }
 
     #[test]
diff --git a/src/raw_input.rs b/src/raw_input.rs
index 12bcba4d..510768fc 100644
--- a/src/raw_input.rs
+++ b/src/raw_input.rs
@@ -172,6 +172,11 @@ impl RawInputFramer {
         self.byte_framer.enable_host_color_scheme_change_tracking();
     }
 
+    #[cfg(any(not(windows), test))]
+    pub(crate) fn enable_host_appearance_query_on_focus(&mut self) {
+        self.byte_framer.enable_host_appearance_query_on_focus();
+    }
+
     pub(crate) fn has_pending_input(&self) -> bool {
         self.byte_framer.has_pending_input()
     }
@@ -216,8 +221,10 @@ pub(crate) struct RawInputByteFramer {
     lone_escape_recently_flushed: bool,
     host_color_replies_awaited: u16,
     host_cell_size_replies_awaited: u16,
+    host_appearance_reply_awaited: bool,
     held_pending_host_reply_esc: bool,
     host_color_scheme_change_tracking: bool,
+    host_appearance_query_on_focus: bool,
     split_coalesced_escape: bool,
 }
 
@@ -252,6 +259,11 @@ impl RawInputByteFramer {
         self.held_pending_host_reply_esc = false;
     }
 
+    fn host_appearance_query_sent(&mut self) {
+        self.host_appearance_reply_awaited = true;
+        self.held_pending_host_reply_esc = false;
+    }
+
     /// Same hold window as `host_color_query_sent`, for the XTWINOPS cell size
     /// reply. Only the Unix client sends this query.
     #[cfg(any(unix, test))]
@@ -261,13 +273,22 @@ impl RawInputByteFramer {
     }
 
     fn awaiting_host_reply(&self) -> bool {
-        self.host_color_replies_awaited > 0 || self.host_cell_size_replies_awaited > 0
+        self.host_color_replies_awaited > 0
+            || self.host_cell_size_replies_awaited > 0
+            || self.host_appearance_reply_awaited
     }
 
     pub(crate) fn enable_host_color_scheme_change_tracking(&mut self) {
         self.host_color_scheme_change_tracking = true;
     }
 
+    /// Arm the bounded host-reply window when focus gain will emit an appearance query.
+    /// If the write or reply fails, a lone Escape is delayed for only one extra flush.
+    #[cfg(any(not(windows), test))]
+    pub(crate) fn enable_host_appearance_query_on_focus(&mut self) {
+        self.host_appearance_query_on_focus = true;
+    }
+
     pub(crate) fn has_pending_input(&self) -> bool {
         !self.buffer.is_empty()
     }
@@ -365,13 +386,16 @@ impl RawInputByteFramer {
             return chunks;
         }
 
-        if self.host_cell_size_replies_awaited > 0 && self.buffer.as_slice() == b"\x1b[" {
+        if (self.host_cell_size_replies_awaited > 0 || self.host_appearance_reply_awaited)
+            && self.buffer.as_slice() == b"\x1b["
+        {
             if !self.held_pending_host_reply_esc {
                 self.held_pending_host_reply_esc = true;
-                tracing::trace!("holding incomplete cell size reply one flush");
+                tracing::trace!("holding incomplete host CSI reply one flush");
                 return chunks;
             }
             self.host_cell_size_replies_awaited = 0;
+            self.host_appearance_reply_awaited = false;
             self.held_pending_host_reply_esc = false;
         }
 
@@ -391,10 +415,20 @@ impl RawInputByteFramer {
         }
 
         if starts_with_incomplete_host_color_scheme_report(&self.buffer) {
+            if self.host_appearance_reply_awaited && !self.held_pending_host_reply_esc {
+                self.held_pending_host_reply_esc = true;
+                tracing::trace!(
+                    len = self.buffer.len(),
+                    "holding incomplete host color scheme report one flush"
+                );
+                return chunks;
+            }
             tracing::debug!(
                 len = self.buffer.len(),
                 "discarding incomplete host color scheme report after input timeout"
             );
+            self.host_appearance_reply_awaited = false;
+            self.held_pending_host_reply_esc = false;
             self.discard_until = Some(ControlStringFamily::HostReplyCsi);
             self.discarded_tail_bytes = 0;
             self.buffer.clear();
@@ -423,6 +457,7 @@ impl RawInputByteFramer {
             // No continuation arrived; give up the window so Escape is not delayed again.
             self.host_color_replies_awaited = 0;
             self.host_cell_size_replies_awaited = 0;
+            self.host_appearance_reply_awaited = false;
             self.held_pending_host_reply_esc = false;
             tracing::warn!(
                 bytes = ?self.buffer,
@@ -522,10 +557,15 @@ impl RawInputByteFramer {
             } else if matches!(event, RawInputEvent::HostCellSizeReport { .. }) {
                 self.host_cell_size_replies_awaited =
                     self.host_cell_size_replies_awaited.saturating_sub(1);
-            } else if self.host_color_scheme_change_tracking
-                && matches!(event, RawInputEvent::HostColorSchemeChanged(_))
+            } else if self.host_appearance_query_on_focus
+                && matches!(event, RawInputEvent::OuterFocusGained)
             {
-                self.host_color_query_sent();
+                self.host_appearance_query_sent();
+            } else if matches!(event, RawInputEvent::HostColorSchemeChanged(_)) {
+                self.host_appearance_reply_awaited = false;
+                if self.host_color_scheme_change_tracking {
+                    self.host_color_query_sent();
+                }
             }
             self.held_pending_host_reply_esc = false;
             chunks.push(self.buffer[..consumed].to_vec());
@@ -580,6 +620,13 @@ pub(crate) fn events_require_host_surface_redraw(
 }
 
 #[cfg(any(not(windows), test))]
+pub(crate) fn events_require_host_terminal_appearance_query(events: &[RawInputEvent]) -> bool {
+    events
+        .iter()
+        .any(|event| matches!(event, RawInputEvent::OuterFocusGained))
+}
+
+#[cfg(any(not(windows), test))]
 pub(crate) fn events_require_host_terminal_theme_query(events: &[RawInputEvent]) -> bool {
     events
         .iter()
@@ -604,6 +651,8 @@ pub fn spawn_input_reader() -> mpsc::Receiver<RawInputEvent> {
         let mut framer = RawInputFramer::for_host_input();
         framer.host_color_query_sent();
         framer.enable_host_color_scheme_change_tracking();
+        #[cfg(not(windows))]
+        framer.enable_host_appearance_query_on_focus();
         let mut pending_palette = Vec::new();
 
         loop {
@@ -1545,6 +1594,20 @@ mod tests {
     }
 
     #[test]
+    fn outer_focus_gained_requests_host_appearance_query() {
+        let gained = parse_raw_input_bytes_sync(b"\x1b[I");
+        let lost = parse_raw_input_bytes_sync(b"\x1b[O");
+        let scheme_report = parse_raw_input_bytes_sync(b"\x1b[?997;1n");
+
+        assert!(events_require_host_terminal_appearance_query(&gained));
+        assert!(!events_require_host_terminal_appearance_query(&lost));
+        assert!(!events_require_host_terminal_appearance_query(
+            &scheme_report
+        ));
+        assert!(events_require_host_terminal_theme_query(&scheme_report));
+    }
+
+    #[test]
     fn parses_ghostty_color_scheme_reports() {
         for bytes in [
             GHOSTTY_COLOR_SCHEME_DARK_REPORT,
@@ -2864,6 +2927,101 @@ mod tests {
     }
 
     #[test]
+    fn opted_in_byte_framer_rearms_after_outer_focus_gained() {
+        let mut framer = RawInputByteFramer::default();
+        framer.enable_host_color_scheme_change_tracking();
+        framer.enable_host_appearance_query_on_focus();
+
+        assert_eq!(framer.push(b"\x1b[I"), vec![b"\x1b[I".to_vec()]);
+        assert!(framer.push(b"\x1b").is_empty());
+        assert!(framer.flush_timeout().is_empty());
+        assert_eq!(
+            framer.push(b"[?997;2n"),
+            vec![GHOSTTY_COLOR_SCHEME_LIGHT_REPORT.to_vec()]
+        );
+    }
+
+    #[test]
+    fn opted_in_byte_framer_reassembles_appearance_reply_split_after_csi() {
+        let mut framer = RawInputByteFramer::default();
+        framer.enable_host_color_scheme_change_tracking();
+        framer.enable_host_appearance_query_on_focus();
+
+        assert_eq!(framer.push(b"\x1b[I"), vec![b"\x1b[I".to_vec()]);
+        assert!(framer.push(b"\x1b[").is_empty());
+        assert!(framer.flush_timeout().is_empty());
+        assert_eq!(
+            framer.push(b"?997;2n"),
+            vec![GHOSTTY_COLOR_SCHEME_LIGHT_REPORT.to_vec()]
+        );
+    }
+
+    #[test]
+    fn opted_in_byte_framer_reassembles_delayed_appearance_reply() {
+        let mut framer = RawInputByteFramer::default();
+        framer.enable_host_color_scheme_change_tracking();
+        framer.enable_host_appearance_query_on_focus();
+
+        assert_eq!(framer.push(b"\x1b[I"), vec![b"\x1b[I".to_vec()]);
+        assert!(framer.push(b"\x1b[?997;").is_empty());
+        assert!(framer.flush_timeout().is_empty());
+        assert_eq!(
+            framer.push(b"2n"),
+            vec![GHOSTTY_COLOR_SCHEME_LIGHT_REPORT.to_vec()]
+        );
+    }
+
+    #[test]
+    fn timed_out_appearance_reply_preserves_pending_color_reply_window() {
+        let mut framer = RawInputByteFramer::default();
+        framer.host_color_query_sent();
+        framer.enable_host_appearance_query_on_focus();
+
+        assert_eq!(framer.push(b"\x1b[I"), vec![b"\x1b[I".to_vec()]);
+        assert!(framer.push(b"\x1b[?997;").is_empty());
+        assert!(framer.flush_timeout().is_empty());
+        assert!(framer.flush_timeout().is_empty());
+        assert!(framer.push(b"2n").is_empty());
+
+        assert!(framer.push(b"\x1b").is_empty());
+        assert!(framer.flush_timeout().is_empty());
+        assert_eq!(
+            framer.push(b"]10;rgb:aaaa/bbbb/cccc\x1b\\"),
+            vec![b"\x1b]10;rgb:aaaa/bbbb/cccc\x1b\\".to_vec()]
+        );
+    }
+
+    #[test]
+    fn disabled_focus_query_does_not_rearm_byte_framer() {
+        let mut framer = RawInputByteFramer::default();
+        framer.enable_host_color_scheme_change_tracking();
+
+        assert_eq!(framer.push(b"\x1b[I"), vec![b"\x1b[I".to_vec()]);
+        assert!(framer.push(b"\x1b").is_empty());
+        assert_eq!(framer.flush_timeout(), vec![b"\x1b".to_vec()]);
+    }
+
+    #[test]
+    fn focus_query_policy_does_not_delay_plain_escape_without_focus() {
+        let mut framer = RawInputByteFramer::default();
+        framer.enable_host_appearance_query_on_focus();
+
+        assert!(framer.push(b"\x1b").is_empty());
+        assert_eq!(framer.flush_timeout(), vec![b"\x1b".to_vec()]);
+    }
+
+    #[test]
+    fn focus_query_without_reply_holds_escape_for_only_one_flush() {
+        let mut framer = RawInputByteFramer::default();
+        framer.enable_host_appearance_query_on_focus();
+
+        assert_eq!(framer.push(b"\x1b[I"), vec![b"\x1b[I".to_vec()]);
+        assert!(framer.push(b"\x1b").is_empty());
+        assert!(framer.flush_timeout().is_empty());
+        assert_eq!(framer.flush_timeout(), vec![b"\x1b".to_vec()]);
+    }
+
+    #[test]
     fn opted_in_byte_framer_rearms_after_color_scheme_report() {
         let mut framer = RawInputByteFramer::default();
         framer.enable_host_color_scheme_change_tracking();
diff --git a/src/terminal_theme.rs b/src/terminal_theme.rs
index ffe78a95..3f04cc4c 100644
--- a/src/terminal_theme.rs
+++ b/src/terminal_theme.rs
@@ -55,6 +55,8 @@ pub enum DefaultColorKind {
 }
 
 pub const HOST_COLOR_QUERY_SEQUENCE: &str = "\x1b]10;?\x1b\\\x1b]11;?\x1b\\";
+#[cfg(any(not(windows), test))]
+pub const HOST_COLOR_SCHEME_QUERY_SEQUENCE: &str = "\x1b[?996n";
 pub const HOST_COLOR_SCHEME_REPORT_ENABLE_SEQUENCE: &str = "\x1b[?2031h";
 pub const HOST_COLOR_SCHEME_REPORT_DISABLE_SEQUENCE: &str = "\x1b[?2031l";