Tray: separate tray and window processes; device list without self

The tray process holds only the icon and starts the same binary with
--window on Open; the window ends when closed, which works on Wayland where
a window cannot be hidden. The devices table now names devices as
hostname (id5), leaves out this device and counts the others.

Co-Authored-By: Claude <noreply@anthropic.com>

crates/tsunagi-tray/Cargo.toml

@@ -27,13 +27,14 @@ tracing-subscriber.workspace = true
 egui-phosphor = "0.9"
 
 # Linux only: tray-icon (already GTK-based there) needs the app to initialise
-# GTK and run its main loop, which eframe/winit do not do.
+# GTK and run its main loop.
 [target.'cfg(target_os = "linux")'.dependencies]
 gtk = "0.18"
 
-# macOS only: set the app's activation policy to Accessory so it lives in the
-# menu bar with no Dock icon. Pinned to eframe's winit so the types unify.
-[target.'cfg(target_os = "macos")'.dependencies]
+# Windows and macOS: the tray process has no GUI toolkit, only an event loop to
+# serve the icon (and, on macOS, the Accessory activation policy that keeps it
+# out of the Dock). Pinned to eframe's winit so the types unify.
+[target.'cfg(any(windows, target_os = "macos"))'.dependencies]
 winit = "0.30"
 
 [lints]

crates/tsunagi-tray/src/app.rs

@@ -1,5 +1,9 @@
-//! The eframe application: wires the tray, the main window, the per-network
+//! The eframe application behind the window: the main view, the per-network
 //! devices windows, and the agent worker.
+//!
+//! It runs in its own process, started by the tray when the user chooses Open
+//! and gone when the window is closed. The tray, which has to outlive the
+//! window, lives in the other process; see [`crate::tray`].
 
 use std::time::Duration;
 
@@ -8,24 +12,20 @@ use eframe::egui;
 use crate::agent::{AgentClient, resolve_socket};
 use crate::devices;
 use crate::stats::Traffic;
-use crate::tray::{Action, Tray};
 use crate::ui::{self, UiState};
 
-/// The tray application state.
+/// The window's state.
 pub(crate) struct App {
     agent: AgentClient,
-    tray: Tray,
     state: UiState,
     /// Traffic rates derived from successive snapshots.
     traffic: Traffic,
     /// The snapshot generation last folded into `traffic`.
     sampled: u64,
-    /// Set when the user chose Quit, so the next close exits rather than hides.
-    quitting: bool,
 }
 
 impl App {
-    /// Builds the app: resolves the socket, starts the worker, creates the tray.
+    /// Builds the app: resolves the socket and starts the worker.
     pub(crate) fn new(
         cc: &eframe::CreationContext<'_>,
         runtime: tokio::runtime::Handle,
@@ -37,40 +37,18 @@ impl App {
         egui_phosphor::add_to_fonts(&mut fonts, egui_phosphor::Variant::Regular);
         ctx.set_fonts(fonts);
 
-        let agent = AgentClient::spawn(&runtime, ctx.clone(), resolve_socket());
-        let tray = Tray::new(ctx)?;
+        let agent = AgentClient::spawn(&runtime, ctx, resolve_socket());
         Ok(Self {
             agent,
-            tray,
             state: UiState::default(),
             traffic: Traffic::default(),
             sampled: 0,
-            quitting: false,
         })
     }
 }
 
 impl eframe::App for App {
     fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
-        for action in self.tray.poll() {
-            match action {
-                Action::Open => {
-                    ctx.send_viewport_cmd(egui::ViewportCommand::Visible(true));
-                    ctx.send_viewport_cmd(egui::ViewportCommand::Focus);
-                }
-                Action::Quit => {
-                    self.quitting = true;
-                    ctx.send_viewport_cmd(egui::ViewportCommand::Close);
-                }
-            }
-        }
-
-        // Closing the main window hides it to the tray; only Quit truly exits.
-        if ctx.input(|i| i.viewport().close_requested()) && !self.quitting {
-            ctx.send_viewport_cmd(egui::ViewportCommand::CancelClose);
-            ctx.send_viewport_cmd(egui::ViewportCommand::Visible(false));
-        }
-
         let snapshot = self.agent.snapshot();
         if snapshot.generation != self.sampled
             && let (Some(Ok(report)), Some(at)) = (&snapshot.status, snapshot.at)
@@ -88,7 +66,7 @@ impl eframe::App for App {
             ctx.copy_text(secret);
         }
 
-        // Keep ticking so fresh status and tray actions are picked up.
+        // Keep ticking so fresh status is picked up.
         ctx.request_repaint_after(Duration::from_millis(500));
     }
 }
@@ -117,7 +95,7 @@ impl App {
             // main window's stay in step.
             let unit = &mut self.state.unit;
             let keep = ctx.show_viewport_immediate(viewport_id, builder, |vctx, _class| {
-                devices::show(vctx, agent, unit, network, traffic);
+                devices::show(vctx, agent, unit, network, &report.endpoint_id, traffic);
                 !vctx.input(|i| i.viewport().close_requested())
             });
             if !keep {

crates/tsunagi-tray/src/devices.rs

@@ -23,22 +23,51 @@ pub(crate) fn title(network: &NetworkReport) -> String {
 /// One row of the device table, built from a tunnel and/or a signed member.
 struct Device<'a> {
     online: bool,
-    name: String,
-    /// What clicking the name copies: `hostname.network` so it resolves, or
-    /// the short id when there is no hostname.
-    copy: String,
+    /// The last hostname seen for it, kept while it is offline.
+    hostname: Option<&'a str>,
+    /// What clicking the hostname copies: `hostname.network`, so it resolves.
+    copy: Option<String>,
+    /// The full endpoint id, which clicking the short form copies.
+    id: &'a str,
     proto: &'a str,
     address: Option<String>,
     handshake_secs: Option<u64>,
     overlay: Option<&'a OverlayPeerReport>,
 }
 
+impl Device<'_> {
+    fn sort_key(&self) -> String {
+        self.hostname.unwrap_or(self.id).to_lowercase()
+    }
+}
+
+/// The first characters of an endpoint id, enough to tell devices apart.
+fn short_id(id: &str) -> String {
+    id.chars().take(5).collect()
+}
+
+/// The device cell: the hostname and, in brackets, the start of the id.
+/// Clicking either copies its own full value.
+fn name_cell(ui: &mut egui::Ui, device: &Device<'_>) {
+    ui.horizontal(|ui| {
+        ui.spacing_mut().item_spacing.x = 4.0;
+        match (device.hostname, &device.copy) {
+            (Some(hostname), Some(copy)) => {
+                format::copy_field(ui, hostname, copy);
+                format::copy_field(ui, &format!("({})", short_id(device.id)), device.id);
+            }
+            _ => format::copy_field(ui, &short_id(device.id), device.id),
+        }
+    });
+}
+
 /// Draws the window body into its viewport.
 pub(crate) fn show(
     ctx: &egui::Context,
     _agent: &AgentClient,
     unit: &mut Unit,
     network: &NetworkReport,
+    own_id: &str,
     traffic: &Traffic,
 ) {
     egui::CentralPanel::default().show(ctx, |ui| {
@@ -60,7 +89,7 @@ pub(crate) fn show(
         format::sparkline(ui, traffic.network(&network.network_id), unit, 48.0);
         ui.add_space(8.0);
 
-        let devices = devices(network);
+        let devices = devices(network, own_id);
         let online = devices.iter().filter(|d| d.online).count();
         ui.label(
             egui::RichText::new(format!(
@@ -123,31 +152,56 @@ fn summary(ui: &mut egui::Ui, network: &NetworkReport) {
         });
 }
 
+/// Every other device this network knows of, from a live tunnel or the signed
+/// membership. This device is in the roster too but is not one of the others.
+fn known_ids<'a>(network: &'a NetworkReport, own_id: &str) -> Vec<&'a str> {
+    let overlay_peers = network
+        .overlay
+        .as_ref()
+        .map(|o| o.peers.as_slice())
+        .unwrap_or(&[]);
+    let mut ids: Vec<&str> = Vec::new();
+    let candidates = overlay_peers
+        .iter()
+        .map(|p| p.endpoint_id.as_str())
+        .chain(network.peers.iter().map(|p| p.endpoint_id.as_str()))
+        .chain(network.members.iter().map(|m| m.endpoint_id.as_str()));
+    for id in candidates {
+        if id != own_id && !ids.contains(&id) {
+            ids.push(id);
+        }
+    }
+    ids
+}
+
+/// How many other devices this network knows of, connected or not.
+pub(crate) fn known_count(network: &NetworkReport, own_id: &str) -> usize {
+    known_ids(network, own_id).len()
+}
+
 /// Builds the device list: every endpoint known from a live tunnel or the
 /// signed membership, online ones first.
-fn devices(network: &NetworkReport) -> Vec<Device<'_>> {
-    let hostnames: HashMap<&str, &str> = network
-        .peers
+fn devices<'a>(network: &'a NetworkReport, own_id: &str) -> Vec<Device<'a>> {
+    // The signed members carry the last name seen, so a device that is away
+    // is still called by it; a live announcement is fresher and wins.
+    let mut hostnames: HashMap<&str, &str> = network
+        .members
         .iter()
-        .filter_map(|p| p.hostname.as_deref().map(|h| (p.endpoint_id.as_str(), h)))
+        .filter_map(|m| m.hostname.as_deref().map(|h| (m.endpoint_id.as_str(), h)))
         .collect();
+    hostnames.extend(
+        network
+            .peers
+            .iter()
+            .filter_map(|p| p.hostname.as_deref().map(|h| (p.endpoint_id.as_str(), h))),
+    );
     let overlay_peers = network
         .overlay
         .as_ref()
         .map(|o| o.peers.as_slice())
         .unwrap_or(&[]);
 
-    let mut ids: Vec<&str> = Vec::new();
-    for peer in overlay_peers {
-        if !ids.contains(&peer.endpoint_id.as_str()) {
-            ids.push(&peer.endpoint_id);
-        }
-    }
-    for member in &network.members {
-        if !ids.contains(&member.endpoint_id.as_str()) {
-            ids.push(&member.endpoint_id);
-        }
-    }
+    let ids = known_ids(network, own_id);
 
     let mut devices: Vec<Device> = ids
         .into_iter()
@@ -156,15 +210,11 @@ fn devices(network: &NetworkReport) -> Vec<Device<'_>> {
             let member = network.members.iter().find(|m| m.endpoint_id == id);
             let online = overlay.is_some_and(|p| p.handshake_secs_ago.is_some());
             let hostname = hostnames.get(id).copied();
-            let name = hostname.map_or_else(
-                || format::short(overlay.map_or(id, |p| p.public_key.as_str())),
-                str::to_string,
-            );
-            let copy = hostname.map_or_else(|| name.clone(), |h| format!("{h}.{}", network.name));
             Device {
                 online,
-                name,
-                copy,
+                hostname,
+                copy: hostname.map(|h| format!("{h}.{}", network.name)),
+                id,
                 proto: overlay.map_or("—", |p| p.protocol.as_str()),
                 address: overlay
                     .and_then(|p| p.address.clone())
@@ -178,7 +228,7 @@ fn devices(network: &NetworkReport) -> Vec<Device<'_>> {
     devices.sort_by(|a, b| {
         b.online
             .cmp(&a.online)
-            .then_with(|| a.name.to_lowercase().cmp(&b.name.to_lowercase()))
+            .then_with(|| a.sort_key().cmp(&b.sort_key()))
     });
     devices
 }
@@ -216,7 +266,7 @@ fn device_table(
             ui.end_row();
 
             for device in devices {
-                format::copy_field(ui, &device.name, &device.copy);
+                name_cell(ui, device);
                 ui.label(device.proto);
                 match &device.address {
                     Some(address) => format::copy_field(ui, address, address),

crates/tsunagi-tray/src/main.rs

@@ -1,12 +1,12 @@
 //! Tray application for managing a running tsunagi agent.
 //!
-//! A small window (networks, their peers and addresses, join/leave, per-network
-//! active and broadcast switches) plus a tray menu (Open, Quit). It is a thin
-//! client over the agent's local control socket — the same interface the CLI
-//! uses — and owns its own runtime, logger and event loop, like the CLI binary.
+//! A tray icon and menu (Open, Quit) that opens a small window (networks, their
+//! peers and addresses, join/leave, per-network active and broadcast switches).
+//! There is no window until Open, and closing it leaves the icon. The window
+//! is a thin client over the agent's local control socket — the same interface
+//! the CLI uses.
 
-// The window is created hidden-to-tray on close rather than exiting; the binary
-// itself may exit on Quit. Nothing here is a library.
+// Nothing here is a library.
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
 mod agent;
@@ -21,38 +21,42 @@ use eframe::egui;
 
 use crate::app::App;
 
+/// The argument that makes this binary the window rather than the tray.
+const WINDOW_ARG: &str = "--window";
+
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let filter = tracing_subscriber::EnvFilter::try_from_default_env()
         .unwrap_or_else(|_| tracing_subscriber::EnvFilter::new("warn"));
     let _ = tracing_subscriber::fmt().with_env_filter(filter).try_init();
 
+    // Two processes from one binary. The tray is what stays; the window is
+    // started by it and ends when it is closed. A window that merely hides is
+    // not something every platform can do — Wayland has no such thing — and a
+    // hidden one that stays is worse than none.
+    if std::env::args().any(|arg| arg == WINDOW_ARG) {
+        window()
+    } else {
+        tray::run()
+    }
+}
+
+/// Runs the window until it is closed.
+fn window() -> Result<(), Box<dyn std::error::Error>> {
     let runtime = tokio::runtime::Builder::new_multi_thread()
         .enable_all()
         .build()?;
     let handle = runtime.handle().clone();
 
-    #[cfg_attr(not(target_os = "macos"), expect(unused_mut))]
-    let mut options = eframe::NativeOptions {
+    let options = eframe::NativeOptions {
         // A fixed, small window; the whole layout targets this size.
         viewport: egui::ViewportBuilder::default()
             .with_title("tsunagi")
+            .with_app_id("tsunagi")
             .with_inner_size([360.0, 600.0])
-            .with_resizable(false)
-            // Start hidden: the app lives in the tray and the window opens from
-            // the menu.
-            .with_visible(false),
+            .with_resizable(false),
         ..Default::default()
     };
 
-    // macOS: live in the menu bar with no Dock icon (tray-only).
-    #[cfg(target_os = "macos")]
-    {
-        options.event_loop_builder = Some(Box::new(|builder| {
-            use winit::platform::macos::{ActivationPolicy, EventLoopBuilderExtMacOS};
-            builder.with_activation_policy(ActivationPolicy::Accessory);
-        }));
-    }
-
     eframe::run_native(
         "tsunagi",
         options,
@@ -63,7 +67,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         }),
     )?;
 
-    // The window loop has ended (Quit); let the runtime wind down.
+    // The window loop has ended; let the runtime wind down.
     drop(runtime);
     Ok(())
 }

crates/tsunagi-tray/src/tray.rs

@@ -1,31 +1,55 @@
-//! The tray icon and its menu.
+//! The tray: the icon, its menu, and starting the window.
 //!
-//! The menu is just Open and Quit; everything else (per-network switches,
-//! join/leave) lives in the window. Menu clicks are read on a background
-//! thread and turned into [`Action`]s, so they are handled even while the
-//! window is hidden and egui would otherwise not be repainting.
+//! This is the process that stays. It holds no window and no GUI toolkit of
+//! its own; choosing Open starts this same binary again as the window, which
+//! is a perfectly ordinary program that ends when it is closed.
 
-use std::sync::mpsc;
+use std::process::{Child, Command};
+use std::sync::{Arc, Mutex};
 
-use eframe::egui;
 use tray_icon::menu::{Menu, MenuEvent, MenuId, MenuItem, PredefinedMenuItem};
 use tray_icon::{Icon, TrayIcon, TrayIconBuilder};
 
-/// What the user picked from the tray menu.
-pub(crate) enum Action {
-    /// Show (and focus) the window.
-    Open,
-    /// Quit the application.
-    Quit,
+/// The window process, when there is one.
+struct Window {
+    child: Mutex<Option<Child>>,
 }
 
-/// The live tray icon plus the channel of menu actions.
-pub(crate) struct Tray {
-    /// Kept alive for as long as the app runs; dropping it removes the icon.
-    /// On Linux the icon lives on the GTK thread instead (it is not `Send`).
-    #[cfg(not(target_os = "linux"))]
-    _icon: TrayIcon,
-    actions: mpsc::Receiver<Action>,
+impl Window {
+    /// Starts the window unless one is already open.
+    ///
+    /// Raising an existing one is not something a process can ask for on
+    /// every platform, so choosing Open while it is open does nothing.
+    fn open(&self) {
+        let mut slot = self.child.lock().unwrap_or_else(|e| e.into_inner());
+        if let Some(child) = slot.as_mut() {
+            match child.try_wait() {
+                Ok(None) => return,
+                _ => *slot = None,
+            }
+        }
+        let started = std::env::current_exe()
+            .map_err(|err| err.to_string())
+            .and_then(|exe| {
+                Command::new(exe)
+                    .arg(crate::WINDOW_ARG)
+                    .spawn()
+                    .map_err(|err| err.to_string())
+            });
+        match started {
+            Ok(child) => *slot = Some(child),
+            Err(err) => eprintln!("cannot open the window: {err}"),
+        }
+    }
+
+    /// Closes the window if it is open.
+    fn close(&self) {
+        let mut slot = self.child.lock().unwrap_or_else(|e| e.into_inner());
+        if let Some(mut child) = slot.take() {
+            let _ = child.kill();
+            let _ = child.wait();
+        }
+    }
 }
 
 /// A built tray icon and the ids of its menu items.
@@ -57,75 +81,91 @@ fn build() -> Result<Built, String> {
     })
 }
 
-impl Tray {
-    /// Builds the tray and starts reading its menu events.
-    ///
-    /// Created on the main thread on macOS and Windows (required on macOS). On
-    /// Linux the tray needs GTK, which eframe/winit never initialise, so it is
-    /// built on a dedicated thread that initialises GTK and runs its main loop.
-    /// `ctx` is used to wake the UI when a menu item is chosen.
-    pub(crate) fn new(ctx: egui::Context) -> Result<Self, String> {
-        #[cfg(target_os = "linux")]
-        let (open_id, quit_id) = {
-            let (ready_tx, ready_rx) = mpsc::sync_channel(1);
-            std::thread::Builder::new()
-                .name("tray-gtk".into())
-                .spawn(move || {
-                    if let Err(err) = gtk::init() {
-                        let _ = ready_tx.send(Err(format!("cannot initialise GTK: {err}")));
-                        return;
-                    }
-                    match build() {
-                        Ok(built) => {
-                            let _ = ready_tx.send(Ok((built.open, built.quit)));
-                            gtk::main();
-                            drop(built.icon);
-                        }
-                        Err(err) => {
-                            let _ = ready_tx.send(Err(err));
-                        }
-                    }
-                })
-                .map_err(|err| err.to_string())?;
-            ready_rx
-                .recv()
-                .map_err(|_| "the tray thread exited before it was ready".to_string())??
-        };
-        #[cfg(not(target_os = "linux"))]
-        let (icon, open_id, quit_id) = {
-            let built = build()?;
-            (built.icon, built.open, built.quit)
-        };
+/// Acts on menu choices as the platform's loop delivers them.
+fn handle_menu(built: &Built, window: Arc<Window>) {
+    let (open, quit) = (built.open.clone(), built.quit.clone());
+    MenuEvent::set_event_handler(Some(move |event: MenuEvent| {
+        if event.id == open {
+            window.open();
+        } else if event.id == quit {
+            window.close();
+            std::process::exit(0);
+        }
+    }));
+}
 
-        let (tx, rx) = mpsc::channel();
-        std::thread::spawn(move || {
-            // The global menu-event channel is fed by the OS event loop.
-            while let Ok(event) = MenuEvent::receiver().recv() {
-                let action = if event.id == open_id {
-                    Action::Open
-                } else if event.id == quit_id {
-                    Action::Quit
-                } else {
-                    continue;
-                };
-                if tx.send(action).is_err() {
-                    break;
-                }
-                ctx.request_repaint();
+/// Shows the icon and runs until Quit.
+///
+/// Linux: the tray needs GTK, which nothing else here initialises, so this
+/// thread does and runs its main loop.
+#[cfg(target_os = "linux")]
+pub(crate) fn run() -> Result<(), Box<dyn std::error::Error>> {
+    gtk::init().map_err(|err| format!("cannot initialise GTK: {err}"))?;
+    let built = build()?;
+    handle_menu(
+        &built,
+        Arc::new(Window {
+            child: Mutex::new(None),
+        }),
+    );
+    gtk::main();
+    drop(built.icon);
+    Ok(())
+}
+
+/// Shows the icon and runs until Quit.
+///
+/// Windows and macOS: the icon needs an event loop on the main thread to be
+/// served, and macOS wants it created once that loop is running. There are no
+/// windows in it; it exists to be pumped.
+#[cfg(not(target_os = "linux"))]
+pub(crate) fn run() -> Result<(), Box<dyn std::error::Error>> {
+    use winit::application::ApplicationHandler;
+    use winit::event::WindowEvent;
+    use winit::event_loop::{ActiveEventLoop, EventLoop};
+    use winit::window::WindowId;
+
+    struct Pump {
+        window: Arc<Window>,
+        icon: Option<TrayIcon>,
+    }
+
+    impl ApplicationHandler for Pump {
+        fn resumed(&mut self, _event_loop: &ActiveEventLoop) {
+            if self.icon.is_some() {
+                return;
             }
-        });
+            match build() {
+                Ok(built) => {
+                    handle_menu(&built, Arc::clone(&self.window));
+                    self.icon = Some(built.icon);
+                }
+                Err(err) => {
+                    eprintln!("cannot create the tray icon: {err}");
+                    std::process::exit(1);
+                }
+            }
+        }
 
-        Ok(Self {
-            #[cfg(not(target_os = "linux"))]
-            _icon: icon,
-            actions: rx,
-        })
+        fn window_event(&mut self, _: &ActiveEventLoop, _: WindowId, _: WindowEvent) {}
     }
 
-    /// The menu actions since the last call.
-    pub(crate) fn poll(&self) -> impl Iterator<Item = Action> + '_ {
-        self.actions.try_iter()
+    let mut builder = EventLoop::builder();
+    // macOS: live in the menu bar with no Dock icon.
+    #[cfg(target_os = "macos")]
+    {
+        use winit::platform::macos::{ActivationPolicy, EventLoopBuilderExtMacOS};
+        builder.with_activation_policy(ActivationPolicy::Accessory);
     }
+    let event_loop = builder.build()?;
+    let mut pump = Pump {
+        window: Arc::new(Window {
+            child: Mutex::new(None),
+        }),
+        icon: None,
+    };
+    event_loop.run_app(&mut pump)?;
+    Ok(())
 }
 
 /// A small round icon, drawn in code so there is no asset to ship yet.

crates/tsunagi-tray/src/ui.rs

@@ -15,6 +15,7 @@ use egui_phosphor::regular as icon;
 use tsunagi::ipc::{NetworkReport, StatusReport};
 
 use crate::agent::{AgentClient, Command, Snapshot};
+use crate::devices;
 use crate::format;
 use crate::stats::{Traffic, Unit};
 
@@ -114,7 +115,7 @@ pub(crate) fn draw(
                         ui.weak("No networks yet — join one below.");
                     }
                     for network in &report.networks {
-                        draw_network(ui, agent, state, traffic, network);
+                        draw_network(ui, agent, state, traffic, network, &report.endpoint_id);
                     }
                 });
         }
@@ -191,6 +192,7 @@ fn draw_network(
     state: &mut UiState,
     traffic: &Traffic,
     network: &NetworkReport,
+    own_id: &str,
 ) {
     ui.add_space(6.0);
     egui::Frame::group(ui.style()).show(ui, |ui| {
@@ -233,7 +235,7 @@ fn draw_network(
                 ui.label(format!(
                     "{} connected · {} known",
                     network.peers.len(),
-                    network.members.len()
+                    devices::known_count(network, own_id)
                 ));
                 ui.end_row();
             });