feat: make headless terminal size configurable (#2829)

refs #2828

1 files changed, 37 insertions, 10 deletions

diff --git a/src/server/headless.rs b/src/server/headless.rs
index ac1e7db2..354b0008 100644
--- a/src/server/headless.rs
+++ b/src/server/headless.rs
@@ -252,10 +252,6 @@ fn dirty_patch_intersects_hyperlinks(
 // Constants
 // ---------------------------------------------------------------------------
 
-/// Default shared runtime size (columns, rows) when no clients are attached.
-const MIN_COLS: u16 = 80;
-const MIN_ROWS: u16 = 24;
-
 /// Timeout for in-flight API requests during shutdown.
 #[allow(dead_code)]
 const SHUTDOWN_API_TIMEOUT: Duration = Duration::from_secs(5);
@@ -326,8 +322,10 @@ pub struct HeadlessServer {
     deferred_alt_screen_reads: Vec<api::ApiRequestMessage>,
     /// Monotonic activity counter used to pick the most recently active client.
     next_activity_stamp: u64,
-    /// Shared pane runtime size derived from the foreground client,
-    /// or MIN_COLS × MIN_ROWS when no clients are connected.
+    /// Configured virtual terminal size used when no clients are connected.
+    headless_size: (u16, u16),
+    /// Shared pane runtime size derived from the foreground client, or the
+    /// configured headless size when no clients are connected.
     effective_size: (u16, u16),
     /// Flag set when shutdown is initiated.
     shutting_down: bool,
@@ -495,6 +493,7 @@ impl HeadlessServer {
         spawn_windows_client_accept_thread(listener, should_quit.clone(), server_event_tx.clone());
 
         let server_keybindings = app_keybindings(&app);
+        let headless_size = app.state.headless_size;
         let (server_config_diagnostic, server_config_diagnostic_without_keybindings) =
             server_config_diagnostic_summaries(config_diagnostics);
         #[cfg(not(unix))]
@@ -521,7 +520,8 @@ impl HeadlessServer {
             pending_alt_screen_reads: Vec::new(),
             deferred_alt_screen_reads: Vec::new(),
             next_activity_stamp: 1,
-            effective_size: (MIN_COLS, MIN_ROWS),
+            headless_size,
+            effective_size: headless_size,
             shutting_down: false,
             handoff_in_progress: false,
             #[cfg(unix)]
@@ -1139,6 +1139,14 @@ impl HeadlessServer {
         }
     }
 
+    fn sync_headless_view_geometry(&mut self) {
+        crate::ui::compute_view_without_resizing_panes(
+            &mut self.app.state,
+            &self.app.terminal_runtimes,
+            Rect::new(0, 0, self.headless_size.0, self.headless_size.1),
+        );
+    }
+
     fn sync_foreground_client_state(&mut self) {
         self.app.direct_graphics_available = self.direct_graphics_available();
         self.app.pixel_mouse_available = self.foreground_client_id.is_some_and(|id| {
@@ -1150,9 +1158,10 @@ impl HeadlessServer {
             self.retire_all_direct_graphics();
         }
         let Some(client_id) = self.foreground_client_id else {
-            self.effective_size = (MIN_COLS, MIN_ROWS);
+            self.effective_size = self.headless_size;
             self.app.state.outer_terminal_focus = None;
             self.app.state.host_cell_size = crate::kitty_graphics::HostCellSize::default();
+            self.sync_headless_view_geometry();
             let server_keybindings = self.server_keybindings.clone();
             apply_keybindings(&mut self.app, &server_keybindings);
             self.sync_visible_server_config_diagnostic(false);
@@ -1160,9 +1169,10 @@ impl HeadlessServer {
         };
         let Some(client) = self.clients.get(&client_id) else {
             self.foreground_client_id = None;
-            self.effective_size = (MIN_COLS, MIN_ROWS);
+            self.effective_size = self.headless_size;
             self.app.state.outer_terminal_focus = None;
             self.app.state.host_cell_size = crate::kitty_graphics::HostCellSize::default();
+            self.sync_headless_view_geometry();
             let server_keybindings = self.server_keybindings.clone();
             apply_keybindings(&mut self.app, &server_keybindings);
             self.sync_visible_server_config_diagnostic(false);
@@ -1507,6 +1517,7 @@ impl HeadlessServer {
         let report = self.app.apply_config_from_disk(notify_success);
         self.app.take_config_reloaded_from_disk();
         self.server_keybindings = app_keybindings(&self.app);
+        self.headless_size = self.app.state.headless_size;
         let (server_config_diagnostic, server_config_diagnostic_without_keybindings) =
             server_config_diagnostic_summaries(&report.diagnostics);
         self.server_config_diagnostic = server_config_diagnostic;
@@ -5306,6 +5317,7 @@ mod tests {
         #[cfg(windows)]
         spawn_windows_client_accept_thread(listener, should_quit.clone(), server_event_tx.clone());
         let server_keybindings = app_keybindings(&app);
+        let headless_size = app.state.headless_size;
 
         HeadlessServer {
             app,
@@ -5329,7 +5341,8 @@ mod tests {
             pending_alt_screen_reads: Vec::new(),
             deferred_alt_screen_reads: Vec::new(),
             next_activity_stamp: 1,
-            effective_size: (MIN_COLS, MIN_ROWS),
+            headless_size,
+            effective_size: headless_size,
             shutting_down: false,
             handoff_in_progress: false,
             #[cfg(unix)]
@@ -5380,6 +5393,20 @@ mod tests {
         }
     }
 
+    #[test]
+    fn default_headless_size_is_effective_without_clients() {
+        let server = test_headless_server();
+
+        assert_eq!(
+            server.headless_size,
+            (
+                crate::config::DEFAULT_HEADLESS_COLS,
+                crate::config::DEFAULT_HEADLESS_ROWS
+            )
+        );
+        assert_eq!(server.effective_size, server.headless_size);
+    }
+
     #[tokio::test]
     async fn headless_api_reads_latest_title_without_spinner_event_flooding() {
         let event_hub = api::EventHub::default();