feat: add tmux-style mouse capture config

2 files changed, 57 insertions, 0 deletions

diff --git a/src/server/headless.rs b/src/server/headless.rs
index f490ec45..3ff3e587 100644
--- a/src/server/headless.rs
+++ b/src/server/headless.rs
@@ -205,6 +205,8 @@ struct ClientConnection {
     graphics_cache: crate::kitty_graphics::HostGraphicsCache,
     /// Whether a render was skipped because the render channel was full.
     render_pending: bool,
+    /// Last host mouse capture mode sent to this client.
+    host_mouse_capture_active: Option<bool>,
     /// Channels for sending framed ServerMessage data to the client writer thread.
     writer: Option<ClientWriter>,
 }
@@ -228,6 +230,7 @@ impl ClientConnection {
             render_state: ClientRenderState::new(render_encoding),
             graphics_cache: crate::kitty_graphics::HostGraphicsCache::default(),
             render_pending: false,
+            host_mouse_capture_active: None,
             writer,
         }
     }
@@ -416,6 +419,7 @@ impl HeadlessServer {
             }
 
             self.drain_client_sound_config_reload_request();
+            self.stream_host_mouse_capture_mode();
 
             self.app.sync_headless_animation_timer(now);
 
@@ -1423,6 +1427,44 @@ impl HeadlessServer {
         changed
     }
 
+    fn stream_host_mouse_capture_mode(&mut self) {
+        let enabled = self.app.state.should_capture_host_mouse();
+        let serialized = match Self::frame_server_message(&ServerMessage::MouseCapture { enabled })
+        {
+            Ok(framed) => framed,
+            Err(err) => {
+                warn!(err = %err, "failed to serialize mouse capture mode for clients");
+                return;
+            }
+        };
+
+        let mut broken_clients: Vec<u64> = Vec::new();
+        for (&client_id, client) in &mut self.clients {
+            if client.host_mouse_capture_active == Some(enabled) {
+                continue;
+            }
+            let Some(writer) = &client.writer else {
+                continue;
+            };
+            if writer.control.send(serialized.clone()).is_err() {
+                debug!(
+                    client_id,
+                    "client writer channel closed during mouse capture update"
+                );
+                broken_clients.push(client_id);
+                continue;
+            }
+            client.host_mouse_capture_active = Some(enabled);
+        }
+
+        for client_id in broken_clients {
+            let foreground_changed = self.remove_client(client_id);
+            if foreground_changed {
+                self.resize_shared_runtime_to_effective_size();
+            }
+        }
+    }
+
     /// Renders the current state to client-sized virtual buffers and streams
     /// frames to all connected clients.
     fn render_and_stream(&mut self) {
diff --git a/src/server/protocol.rs b/src/server/protocol.rs
index 8748c41c..e0a3c4a0 100644
--- a/src/server/protocol.rs
+++ b/src/server/protocol.rs
@@ -294,6 +294,12 @@ pub enum ServerMessage {
 
     /// Client-local sound config changed on disk; refresh it without reconnecting.
     ReloadSoundConfig,
+
+    /// Whether the client should currently capture host mouse input.
+    MouseCapture {
+        /// True when Herdr mouse UI is enabled or the focused pane app requests mouse reporting.
+        enabled: bool,
+    },
 }
 
 // ---------------------------------------------------------------------------
@@ -799,6 +805,15 @@ mod tests {
         assert_eq!(msg, decoded);
     }
 
+    #[test]
+    fn server_mouse_capture_roundtrip() {
+        let msg = ServerMessage::MouseCapture { enabled: true };
+        let encoded = bincode::serde::encode_to_vec(&msg, bincode::config::standard()).unwrap();
+        let (decoded, _): (ServerMessage, _) =
+            bincode::serde::decode_from_slice(&encoded, bincode::config::standard()).unwrap();
+        assert_eq!(msg, decoded);
+    }
+
     // ---- Framing ----
 
     #[test]