feat: add focus-follows-mouse option

zellij-server/src/lib.rs

@@ -400,6 +400,7 @@ impl SessionMetaData {
                         .options
                         .advanced_mouse_actions
                         .unwrap_or(true),
+                    focus_follows_mouse: new_config.options.focus_follows_mouse.unwrap_or(false),
                 })
                 .unwrap();
             self.senders

zellij-server/src/screen.rs

@@ -375,6 +375,7 @@ pub enum ScreenInstruction {
         stacked_resize: bool,
         default_editor: Option<PathBuf>,
         advanced_mouse_actions: bool,
+        focus_follows_mouse: bool,
     },
     RerunCommandPane(u32), // u32 - terminal pane id
     ResizePaneWithId(ResizeStrategy, PaneId),
@@ -745,6 +746,7 @@ pub(crate) struct Screen {
     web_sharing: WebSharing,
     current_pane_group: Rc<RefCell<PaneGroups>>,
     advanced_mouse_actions: bool,
+    focus_follows_mouse: bool,
     currently_marking_pane_group: Rc<RefCell<HashMap<ClientId, bool>>>,
     // the below are the configured values - the ones that will be set if and when the web server
     // is brought online
@@ -779,6 +781,7 @@ impl Screen {
         web_clients_allowed: bool,
         web_sharing: WebSharing,
         advanced_mouse_actions: bool,
+        focus_follows_mouse: bool,
         web_server_ip: IpAddr,
         web_server_port: u16,
     ) -> Self {
@@ -830,6 +833,7 @@ impl Screen {
             current_pane_group: Rc::new(RefCell::new(current_pane_group)),
             currently_marking_pane_group: Rc::new(RefCell::new(HashMap::new())),
             advanced_mouse_actions,
+            focus_follows_mouse,
             web_server_ip,
             web_server_port,
         }
@@ -1466,6 +1470,7 @@ impl Screen {
             self.current_pane_group.clone(),
             self.currently_marking_pane_group.clone(),
             self.advanced_mouse_actions,
+            self.focus_follows_mouse,
             self.web_server_ip,
             self.web_server_port,
         );
@@ -2680,6 +2685,7 @@ impl Screen {
         stacked_resize: bool,
         default_editor: Option<PathBuf>,
         advanced_mouse_actions: bool,
+        focus_follows_mouse: bool,
         client_id: ClientId,
     ) -> Result<()> {
         let should_support_arrow_fonts = !simplified_ui;
@@ -2695,6 +2701,7 @@ impl Screen {
         self.copy_options.copy_on_select = copy_on_select;
         self.draw_pane_frames = pane_frames;
         self.advanced_mouse_actions = advanced_mouse_actions;
+        self.focus_follows_mouse = focus_follows_mouse;
         self.default_mode_info
             .update_arrow_fonts(should_support_arrow_fonts);
         self.default_mode_info
@@ -2715,6 +2722,7 @@ impl Screen {
             tab.set_pane_frames(pane_frames);
             tab.update_arrow_fonts(should_support_arrow_fonts);
             tab.update_advanced_mouse_actions(advanced_mouse_actions);
+            tab.update_focus_follows_mouse(focus_follows_mouse);
         }
 
         // client specific configuration
@@ -2873,6 +2881,10 @@ impl Screen {
                         self.clear_pane_group(&client_id);
                     }
                 }
+                if let Some(_pane_id) = mouse_effect.focus_changed {
+                    // Focus change is already handled in the tab, no additional action needed
+                    // The state_changed flag will trigger a re-render
+                }
                 if mouse_effect.state_changed {
                     let _ = self.log_and_report_session_state();
                 }
@@ -3268,6 +3280,7 @@ pub(crate) fn screen_thread_main(
         .unwrap_or(false);
     let web_sharing = config_options.web_sharing.unwrap_or_else(Default::default);
     let advanced_mouse_actions = config_options.advanced_mouse_actions.unwrap_or(true);
+    let focus_follows_mouse = config_options.focus_follows_mouse.unwrap_or(false);
 
     let thread_senders = bus.senders.clone();
     let mut screen = Screen::new(
@@ -3304,6 +3317,7 @@ pub(crate) fn screen_thread_main(
         web_clients_allowed,
         web_sharing,
         advanced_mouse_actions,
+        focus_follows_mouse,
         web_server_ip,
         web_server_port,
     );
@@ -5224,6 +5238,7 @@ pub(crate) fn screen_thread_main(
                 stacked_resize,
                 default_editor,
                 advanced_mouse_actions,
+                focus_follows_mouse,
             } => {
                 screen
                     .reconfigure(
@@ -5242,6 +5257,7 @@ pub(crate) fn screen_thread_main(
                         stacked_resize,
                         default_editor,
                         advanced_mouse_actions,
+                        focus_follows_mouse,
                         client_id,
                     )
                     .non_fatal();

zellij-server/src/tab/mod.rs

@@ -158,6 +158,7 @@ pub struct MouseEffect {
     pub group_toggle: Option<PaneId>,
     pub group_add: Option<PaneId>,
     pub ungroup: bool,
+    pub focus_changed: Option<PaneId>,
 }
 
 impl MouseEffect {
@@ -168,6 +169,7 @@ impl MouseEffect {
             group_toggle: None,
             group_add: None,
             ungroup: false,
+            focus_changed: None,
         }
     }
     pub fn leave_clipboard_message() -> Self {
@@ -177,6 +179,7 @@ impl MouseEffect {
             group_toggle: None,
             group_add: None,
             ungroup: false,
+            focus_changed: None,
         }
     }
     pub fn state_changed_and_leave_clipboard_message() -> Self {
@@ -186,6 +189,7 @@ impl MouseEffect {
             group_toggle: None,
             group_add: None,
             ungroup: false,
+            focus_changed: None,
         }
     }
     pub fn group_toggle(pane_id: PaneId) -> Self {
@@ -195,6 +199,7 @@ impl MouseEffect {
             group_toggle: Some(pane_id),
             group_add: None,
             ungroup: false,
+            focus_changed: None,
         }
     }
     pub fn group_add(pane_id: PaneId) -> Self {
@@ -204,6 +209,7 @@ impl MouseEffect {
             group_toggle: None,
             group_add: Some(pane_id),
             ungroup: false,
+            focus_changed: None,
         }
     }
     pub fn ungroup() -> Self {
@@ -213,6 +219,17 @@ impl MouseEffect {
             group_toggle: None,
             group_add: None,
             ungroup: true,
+            focus_changed: None,
+        }
+    }
+    pub fn focus_changed(pane_id: PaneId) -> Self {
+        MouseEffect {
+            state_changed: true,
+            leave_clipboard_message: true,
+            group_toggle: None,
+            group_add: None,
+            ungroup: false,
+            focus_changed: Some(pane_id),
         }
     }
 }
@@ -269,6 +286,7 @@ pub(crate) struct Tab {
     mouse_hover_pane_id: HashMap<ClientId, PaneId>,
     current_pane_group: Rc<RefCell<PaneGroups>>,
     advanced_mouse_actions: bool,
+    focus_follows_mouse: bool,
     currently_marking_pane_group: Rc<RefCell<HashMap<ClientId, bool>>>,
     connected_clients_in_app: Rc<RefCell<HashMap<ClientId, bool>>>, // bool -> is_web_client
     // the below are the configured values - the ones that will be set if and when the web server
@@ -694,6 +712,7 @@ impl Tab {
         current_pane_group: Rc<RefCell<PaneGroups>>,
         currently_marking_pane_group: Rc<RefCell<HashMap<ClientId, bool>>>,
         advanced_mouse_actions: bool,
+        focus_follows_mouse: bool,
         web_server_ip: IpAddr,
         web_server_port: u16,
     ) -> Self {
@@ -796,6 +815,7 @@ impl Tab {
             current_pane_group,
             currently_marking_pane_group,
             advanced_mouse_actions,
+            focus_follows_mouse,
             connected_clients_in_app,
             web_server_ip,
             web_server_port,
@@ -4405,6 +4425,18 @@ impl Tab {
                 let pane_is_selectable = pane.selectable();
                 if self.advanced_mouse_actions && pane_is_selectable {
                     self.mouse_hover_pane_id.insert(client_id, pane_id);
+
+                    // Focus-follows-mouse logic
+                    if self.focus_follows_mouse {
+                        let current_active_pane = self.get_active_pane_id(client_id);
+                        if current_active_pane != Some(pane_id) {
+                            if let Err(e) = self.focus_pane_with_id(pane_id, false, client_id) {
+                                log::error!("Failed to focus pane in focus-follows-mouse: {}", e);
+                            } else {
+                                return Ok(MouseEffect::focus_changed(pane_id));
+                            }
+                        }
+                    }
                 } else if self.advanced_mouse_actions {
                     self.mouse_hover_pane_id.remove(&client_id);
                 }
@@ -5225,6 +5257,9 @@ impl Tab {
     pub fn update_advanced_mouse_actions(&mut self, advanced_mouse_actions: bool) {
         self.advanced_mouse_actions = advanced_mouse_actions;
     }
+    pub fn update_focus_follows_mouse(&mut self, focus_follows_mouse: bool) {
+        self.focus_follows_mouse = focus_follows_mouse;
+    }
     pub fn update_web_sharing(&mut self, web_sharing: WebSharing) {
         let old_value = self.web_sharing;
         self.web_sharing = web_sharing;

zellij-server/src/tab/unit/tab_integration_tests.rs

@@ -271,6 +271,7 @@ fn create_new_tab(size: Size, default_mode: ModeInfo) -> Tab {
         current_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );
@@ -352,6 +353,7 @@ fn create_new_tab_without_pane_frames(size: Size, default_mode: ModeInfo) -> Tab
         current_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );
@@ -448,6 +450,7 @@ fn create_new_tab_with_swap_layouts(
         current_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );
@@ -545,6 +548,7 @@ fn create_new_tab_with_os_api(
         current_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );
@@ -628,6 +632,7 @@ fn create_new_tab_with_layout(size: Size, default_mode: ModeInfo, layout: &str)
         current_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );
@@ -725,6 +730,7 @@ fn create_new_tab_with_mock_pty_writer(
         current_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );
@@ -813,6 +819,7 @@ fn create_new_tab_with_sixel_support(
         current_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );

zellij-server/src/tab/unit/tab_tests.rs

@@ -211,6 +211,7 @@ fn create_new_tab(size: Size, stacked_resize: bool) -> Tab {
         current_pane_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );
@@ -291,6 +292,7 @@ fn create_new_tab_with_layout(size: Size, layout: TiledPaneLayout) -> Tab {
         current_pane_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );
@@ -377,6 +379,7 @@ fn create_new_tab_with_cell_size(
         current_pane_group,
         currently_marking_pane_group,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );

zellij-server/src/unit/screen_tests.rs

@@ -302,6 +302,7 @@ fn create_new_screen(size: Size, advanced_mouse_actions: bool) -> Screen {
         false,
         web_sharing,
         advanced_mouse_actions,
+        false, // focus_follows_mouse
         web_server_ip,
         web_server_port,
     );

zellij-utils/src/input/options.rs

@@ -220,6 +220,12 @@ pub struct Options {
     #[serde(default)]
     pub advanced_mouse_actions: Option<bool>,
 
+    /// Whether to automatically focus panes when mouse hovers over them
+    /// default is false
+    #[clap(long, value_parser)]
+    #[serde(default)]
+    pub focus_follows_mouse: Option<bool>,
+
     // these are intentionally excluded from the CLI options as they must be specified in the
     // configuration file
     pub web_server_ip: Option<IpAddr>,
@@ -315,6 +321,7 @@ impl Options {
         let show_startup_tips = other.show_startup_tips.or(self.show_startup_tips);
         let show_release_notes = other.show_release_notes.or(self.show_release_notes);
         let advanced_mouse_actions = other.advanced_mouse_actions.or(self.advanced_mouse_actions);
+        let focus_follows_mouse = other.focus_follows_mouse.or(self.focus_follows_mouse);
         let web_server_ip = other.web_server_ip.or(self.web_server_ip);
         let web_server_port = other.web_server_port.or(self.web_server_port);
         let web_server_cert = other
@@ -362,6 +369,7 @@ impl Options {
             show_startup_tips,
             show_release_notes,
             advanced_mouse_actions,
+            focus_follows_mouse,
             web_server_ip,
             web_server_port,
             web_server_cert,
@@ -433,6 +441,7 @@ impl Options {
         let show_release_notes = other.show_release_notes.or(self.show_release_notes);
         let advanced_mouse_actions = other.advanced_mouse_actions.or(self.advanced_mouse_actions);
         let web_server_ip = other.web_server_ip.or(self.web_server_ip);
+        let focus_follows_mouse = other.focus_follows_mouse.or(self.focus_follows_mouse);
         let web_server_port = other.web_server_port.or(self.web_server_port);
         let web_server_cert = other
             .web_server_cert
@@ -479,6 +488,7 @@ impl Options {
             show_startup_tips,
             show_release_notes,
             advanced_mouse_actions,
+            focus_follows_mouse,
             web_server_ip,
             web_server_port,
             web_server_cert,
@@ -556,6 +566,7 @@ impl From<CliOptions> for Options {
             show_startup_tips: opts.show_startup_tips,
             show_release_notes: opts.show_release_notes,
             advanced_mouse_actions: opts.advanced_mouse_actions,
+            focus_follows_mouse: opts.focus_follows_mouse,
             web_server_ip: opts.web_server_ip,
             web_server_port: opts.web_server_port,
             web_server_cert: opts.web_server_cert,