clippy fix

.cargo/config.toml

@@ -0,0 +1,7 @@
+# Link with mold from the repo itself, so `cargo build`/`cargo run` do not
+# depend on a machine-local ~/.cargo/config.toml. -fuse-ld is understood by
+# both the clang and gcc drivers, so this works with whatever `linker` the
+# caller has configured (mold is in the devShell PATH; the nix build gets it
+# via flake.nix).
+[target.x86_64-unknown-linux-gnu]
+rustflags = ["-C", "link-arg=-fuse-ld=mold"]

Cargo.toml

@@ -1,8 +1,29 @@
-[package]
+[workspace]
-name = "barbar"
+members = ["crates/core", "crates/common", "crates/modules", "crates/services"]
+resolver = "2"
+
+[workspace.package]
 version = "0.1.0"
 edition = "2021"
 
-[dependencies]
+[workspace.dependencies]
-iced = { version = "0.14", default-features = false, features = ["wgpu", "wayland", "crisp", "web-colors", "thread-pool", "advanced"] }
+iced = { version = "0.14", default-features = false, features = ["wgpu", "wayland", "crisp", "web-colors", "thread-pool", "advanced", "tokio"] }
 iced_layershell = { version = "0.19", default-features = false }
+tokio = { version = "1", features = ["rt-multi-thread", "macros", "sync", "time"] }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+chrono = "0.4"
+toml = "1.1"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+serde_yaml = "0.9"
+thiserror = "2"
+clap = { version = "4.6.6", features = ["derive", "help"] }
+
+# Dependencies get light optimization in dev so wgpu/iced stay usable at
+# runtime without paying full O3 codegen on every cold build; workspace
+# members keep dev defaults (opt-level 0). Line-tables-only debuginfo keeps
+# the dev binary and target/ from ballooning.
+[profile.dev.package."*"]
+opt-level = 1
+debug = "line-tables-only"

Cargo.toml.old

@@ -0,0 +1,10 @@
+[package]
+name = "barbar"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+iced = { version = "0.14", default-features = false, features = ["wgpu", "wayland", "crisp", "web-colors", "thread-pool", "advanced", "tokio"] }
+iced_layershell = { version = "0.19", default-features = false }
+tokio = { version = "1", features = ["rt-multi-thread", "macros", "sync", "time"] }
+chrono = "0.4"

crates/common/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "common"
+version.workspace = true
+edition.workspace = true
+
+[lib]
+name = "common"
+path = "src/lib.rs"
+
+[dependencies]
+iced = { workspace = true }
+iced_layershell = { workspace = true }
+toml = { workspace = true }
+serde = { workspace = true }
+chrono = { workspace = true }
+serde_json = { workspace = true }

crates/common/src/config.rs

@@ -0,0 +1,43 @@
+use serde::{Deserialize, Serialize};
+use toml::Table;
+
+use crate::display::Display;
+
+#[derive(Serialize, Deserialize)]
+pub struct BarbarConfig {
+    #[serde(default)]
+    pub display: Display,
+    pub ups: Option<i32>, // Updates per second
+    pub order: ModuleOrder,
+    pub modules: Option<Table>,  // 'clock': [clock settings]
+    pub services: Option<Table>, // 'clockticker': [clockticker settings]
+}
+
+#[derive(serde::Deserialize, Serialize, Clone, Copy, Debug)]
+#[serde(rename_all = "lowercase")]
+pub enum Modules {
+    Audio,
+    Battery,
+    Clock,
+    Weather,
+    Workspaces,
+}
+
+impl Modules {
+    pub fn to_string(&self) -> &str {
+        match self {
+            Modules::Audio => "audio",
+            Modules::Battery => "battery",
+            Modules::Clock => "clock",
+            Modules::Weather => "weather",
+            Modules::Workspaces => "workspaces",
+        }
+    }
+}
+
+#[derive(Deserialize, Serialize, Clone)]
+pub struct ModuleOrder {
+    pub left: Vec<Modules>,
+    pub middle: Vec<Modules>,
+    pub right: Vec<Modules>,
+}

crates/common/src/display.rs

@@ -0,0 +1,91 @@
+//! `[display]` config section, converted into `iced_layershell` settings.
+//!
+//! Keeps the bar surface's geometry and renderer flags in one place, so `core`
+//! only reads config and hands the result straight to the daemon.
+
+use iced::{Font, Pixels};
+use iced_layershell::reexport::{Anchor, KeyboardInteractivity};
+use iced_layershell::settings::{LayerShellSettings, Settings, StartMode};
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+
+/// Bar text font, matching quickshell's `CaskaydiaCove NFM`.
+const DEFAULT_FONT: &str = "CaskaydiaCove NFM";
+/// Bar height in logical px when `[display].height` is omitted.
+const DEFAULT_HEIGHT: u32 = 36;
+/// Default text size in logical px.
+const DEFAULT_TEXT_SIZE: f32 = 16.0;
+/// Default horizontal padding between the bar edge and its content, logical px.
+const DEFAULT_PADDING: f32 = 8.0;
+/// Default gap between modules in the bar, logical px.
+const DEFAULT_SPACING: f32 = 8.0;
+
+/// Parsed `[display]` table.
+#[derive(Deserialize, Serialize, Clone, Debug)]
+#[serde(default)]
+pub struct Display {
+    /// Output to pin the bar to; `None` follows the active output.
+    pub monitor: Option<String>,
+    /// Bar height in logical px; the same strip is reserved exclusively.
+    pub height: u32,
+    /// MSAA for triangle primitives (Canvas/meshes). Quads — borders,
+    /// rounded rectangles — are already anti-aliased analytically, so this
+    /// does not change them.
+    pub antialiasing: bool,
+    /// Default text size in logical px.
+    pub default_text_size: f32,
+    /// Left/right padding between the bar edge and its content, logical px.
+    pub padding: f32,
+    /// Gap between modules in the bar, logical px.
+    pub spacing: f32,
+    /// Path to a base16 YAML scheme to theme the bar with; system theme if
+    /// absent.
+    pub theme: Option<PathBuf>,
+}
+
+impl Default for Display {
+    fn default() -> Self {
+        Self {
+            monitor: None,
+            height: DEFAULT_HEIGHT,
+            antialiasing: false,
+            default_text_size: DEFAULT_TEXT_SIZE,
+            padding: DEFAULT_PADDING,
+            spacing: DEFAULT_SPACING,
+            theme: None,
+        }
+    }
+}
+
+impl Display {
+    /// Output the bar starts on.
+    pub fn start_mode(&self) -> StartMode {
+        match &self.monitor {
+            Some(name) => StartMode::TargetScreen(name.clone()),
+            None => StartMode::Active,
+        }
+    }
+
+    /// Bar surface placement: full width, top, reserved strip of `height`.
+    pub fn layer_settings(&self) -> LayerShellSettings {
+        LayerShellSettings {
+            size: Some((0, self.height)),
+            exclusive_zone: self.height as i32,
+            anchor: Anchor::Top | Anchor::Left | Anchor::Right,
+            start_mode: self.start_mode(),
+            keyboard_interactivity: KeyboardInteractivity::None,
+            ..Default::default()
+        }
+    }
+
+    /// Full daemon settings: layer-shell placement plus iced renderer flags.
+    pub fn settings(&self) -> Settings {
+        Settings {
+            layer_settings: self.layer_settings(),
+            default_font: Font::with_name(DEFAULT_FONT),
+            default_text_size: Pixels(self.default_text_size),
+            antialiasing: self.antialiasing,
+            ..Default::default()
+        }
+    }
+}

crates/common/src/effect.rs

@@ -0,0 +1,27 @@
+use iced::{window, Rectangle};
+
+use crate::Wire;
+
+#[derive(Clone, Debug)]
+pub struct PopupSettings {
+    // pub name: String,
+    pub module_id: String,
+    pub element_id: String,
+    pub gap: i32,
+}
+
+/// What a module asks the app to do — the single effect vocabulary shared by
+/// modules and app, so mapping module output into a `Message` is a plain
+/// `.map(Message::Effect)` with no mirror enum.
+#[derive(Debug, Clone)]
+pub enum ModuleEffect {
+    /// Toggle a popup for the given module id (element id anchors it).
+    RequestPopup(PopupSettings),
+    /// A widget-tree pass reported a module's laid-out bounds; anchor the
+    /// popup there. App-internal, but one effect type keeps routing trivial.
+    BoundsFound(Rectangle, PopupSettings),
+    /// Request removal of the popup surface.
+    ClosePopup(window::Id),
+    /// Route a wire to its target (a module, a service inbox, or a topic).
+    Send(Wire),
+}

crates/common/src/lib.rs

@@ -0,0 +1,23 @@
+//! Barbar's protocol crate: the types that cross crate boundaries.
+//!
+//! Nothing here may reference app-level types (`Message`, `Msg`,
+//! layer-shell effects). `common` is the hub every other crate depends on,
+//! so it must stay acyclic and pure.
+
+mod config;
+mod display;
+mod effect;
+mod messages;
+mod module;
+mod reusable_elements;
+mod service;
+mod wire;
+
+pub use config::{BarbarConfig, Modules};
+pub use display::Display;
+pub use effect::{ModuleEffect, PopupSettings};
+pub use messages::*;
+pub use module::BarModule;
+pub use reusable_elements::pill;
+pub use service::Service;
+pub use wire::{Endpoint, Inbox, Namespace, Target, Wire};

crates/common/src/messages/mod.rs

@@ -0,0 +1,13 @@
+//! Wire vocabulary: every message type that crosses a crate boundary.
+//!
+//! Laid out to mirror the crate that owns the behavior: `modules/*` are
+//! messages a bar module sends or receives, `services/*` are messages a
+//! service produces or accepts. Types live here so either side can name a
+//! payload without depending on the other's crate; only the types are
+//! shared, the behavior stays in the owning crate.
+
+pub mod modules;
+pub mod services;
+
+pub use modules::*;
+pub use services::*;

crates/common/src/messages/modules/battery.rs

@@ -0,0 +1,8 @@
+//! Battery module messages.
+
+/// A module-local message for the battery tile (bar/popup interactions).
+#[derive(Clone)]
+pub enum BatteryAction {
+    /// Open the battery info popup.
+    OpenPopup,
+}

crates/common/src/messages/modules/clock.rs

@@ -0,0 +1,10 @@
+//! Clock module messages.
+
+/// A module-local message for the clock (bar/popup interactions).
+#[derive(Clone)]
+pub enum ClockMsg {
+    /// Toggle the seconds suffix.
+    ToggleSeconds,
+    /// Open the big-time popup.
+    OpenPopup,
+}

crates/common/src/messages/modules/mod.rs

@@ -0,0 +1,9 @@
+//! Messages owned by bar modules.
+
+mod battery;
+mod clock;
+mod weather;
+
+pub use battery::*;
+pub use clock::*;
+pub use weather::*;

crates/common/src/messages/modules/weather.rs

@@ -0,0 +1,7 @@
+//! Weather module messages.
+
+/// A module-local message for the weather tile (bar/popup interactions).
+#[derive(Clone)]
+pub enum WeatherKind {
+    Poke,
+}

crates/common/src/messages/services/battery.rs

@@ -0,0 +1,44 @@
+//! Battery service messages.
+
+use crate::Service;
+
+/// Route key a module subscribes under to receive battery events. One
+/// stream carries every event; the [`BatteryEvent`] payload tags which one,
+/// so modules filter on it.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum BatteryMsg {
+    Events,
+}
+
+impl BatteryMsg {
+    /// Route key a module subscribes under to receive this service's events.
+    pub fn key(self) -> Service {
+        Service(match self {
+            Self::Events => "battery.events",
+        })
+    }
+}
+
+/// Charge state of the first battery, without depending on D-Bus types
+/// outside the service itself.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Default)]
+pub enum BatteryStatus {
+    #[default]
+    Unknown,
+    Charging,
+    Discharging,
+    Empty,
+    Full,
+}
+
+/// A battery event, published to subscribers of the events key.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum BatteryEvent {
+    /// Charge percentage changed (0..=100).
+    PercentageChanged(i32),
+    /// Charging state changed.
+    StatusChanged(BatteryStatus),
+    /// Seconds until full (charging) or empty (discharging) changed;
+    /// `None` when unknown or not applicable.
+    EtaChanged(Option<u64>),
+}

crates/common/src/messages/services/datetime.rs

@@ -0,0 +1,27 @@
+//! Clock service messages.
+
+use crate::Service;
+
+/// What a clock subscription wants: the tick interval and payload selector.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum ClockKind {
+    Mins,
+    Seconds,
+}
+
+impl ClockKind {
+    /// Route key a module subscribes under to receive this kind's ticks.
+    pub fn key(self) -> Service {
+        Service(match self {
+            Self::Mins => "clock.mins",
+            Self::Seconds => "clock.seconds",
+        })
+    }
+}
+
+/// Clock tick: the kind is the variant, the rendered time the parameter.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum ClockPayload {
+    Mins(String),
+    Seconds(String),
+}

crates/common/src/messages/services/hyprland.rs

@@ -0,0 +1,33 @@
+//! Hyprland compositor messages.
+
+use crate::Service;
+
+/// Route key a module subscribes under to receive compositor events. One
+/// stream carries every event; the [`HyprlandEvent`] payload tags which one,
+/// so modules filter on it.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum HyprlandMsg {
+    Events,
+}
+
+impl HyprlandMsg {
+    /// Route key a module subscribes under to receive this service's events.
+    pub fn key(self) -> Service {
+        Service("hyprland.events")
+    }
+}
+
+/// A hyprland compositor event, published to subscribers of the events key.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum HyprlandEvent {
+    /// Focused workspace changed.
+    WorkspaceChanged { id: i32, name: String },
+    /// A workspace was created.
+    WorkspaceAdded { id: i32, name: String },
+    /// A workspace was destroyed.
+    WorkspaceRemoved { id: i32, name: String },
+    /// Focused window changed; empty class/title mean no window is focused.
+    ActiveWindow { class: String, title: String },
+    /// Focused monitor changed.
+    Monitor { name: String },
+}

crates/common/src/messages/services/mod.rs

@@ -0,0 +1,13 @@
+//! Messages owned by services.
+
+mod battery;
+mod datetime;
+mod hyprland;
+mod pipewire;
+mod weather;
+
+pub use battery::*;
+pub use datetime::*;
+pub use hyprland::*;
+pub use pipewire::*;
+pub use weather::*;

crates/common/src/messages/services/pipewire.rs

@@ -0,0 +1,36 @@
+//! PipeWire audio messages.
+
+use crate::Service;
+
+/// Route key a module subscribes under to receive the audio state.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum PipewireMsg {
+    State,
+}
+
+impl PipewireMsg {
+    /// Route key a module subscribes under to receive this service's state.
+    pub fn key(self) -> Service {
+        Service(match self {
+            Self::State => "pipewire.state",
+        })
+    }
+}
+
+/// One audio node's level, as PipeWire reports it.
+#[derive(Clone, Copy, PartialEq, Debug, Default)]
+pub struct AudioNode {
+    /// Linear volume fraction: 1.0 is 100%, above 1.0 is boost.
+    pub volume: f32,
+    /// Node is muted; `volume` is still the level it will unmute to.
+    pub muted: bool,
+}
+
+/// Default sink and default source state, published whenever either changes.
+#[derive(Clone, Copy, PartialEq, Debug, Default)]
+pub struct PipewireState {
+    /// Default playback device.
+    pub sink: AudioNode,
+    /// Default capture device.
+    pub source: AudioNode,
+}

crates/common/src/messages/services/weather.rs

@@ -0,0 +1,77 @@
+use std::{any::Any, sync::Arc};
+
+use serde::Deserialize;
+
+use crate::Service;
+
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum WeatherMsg {
+    State,
+}
+
+impl WeatherMsg {
+    pub fn key(self) -> Service {
+        Service(match self {
+            Self::State => "weather.state",
+        })
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct WeatherPayload {
+    pub kind: WeatherMsg,
+    pub payload: Arc<dyn Any + Send + Sync>,
+}
+
+/// Open-Meteo forecast response.
+#[derive(Debug, Deserialize)]
+pub struct WeatherResponse {
+    pub latitude: f64,
+    pub longitude: f64,
+    pub generationtime_ms: f64,
+    pub utc_offset_seconds: i64,
+    pub timezone: String,
+    pub timezone_abbreviation: String,
+    pub elevation: f64,
+    pub hourly_units: HourlyUnits,
+    pub hourly: Hourly,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct HourlyUnits {
+    pub time: String,
+    pub temperature_2m: String,
+    pub rain: String,
+    pub showers: String,
+    pub precipitation: String,
+    pub relative_humidity_2m: String,
+}
+
+#[derive(Debug, Deserialize, Clone)]
+pub struct Hourly {
+    #[serde(deserialize_with = "naive_dt::deserialize")]
+    pub time: Vec<chrono::NaiveDateTime>,
+    pub temperature_2m: Vec<f64>,
+    pub rain: Vec<f64>,
+    pub showers: Vec<f64>,
+    pub precipitation: Vec<f64>,
+    pub relative_humidity_2m: Vec<f64>,
+}
+
+/// Open-Meteo emits local timestamps as `"%Y-%m-%dT%H:%M"` (no seconds).
+mod naive_dt {
+    use chrono::NaiveDateTime;
+    use serde::{de::Error, Deserialize, Deserializer};
+
+    const FMT: &str = "%Y-%m-%dT%H:%M";
+
+    pub fn deserialize<'de, D>(d: D) -> Result<Vec<NaiveDateTime>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        Vec::<String>::deserialize(d)?
+            .iter()
+            .map(|s| NaiveDateTime::parse_from_str(s, FMT).map_err(D::Error::custom))
+            .collect()
+    }
+}

crates/common/src/module.rs

@@ -0,0 +1,35 @@
+use std::error::Error;
+
+use iced::window;
+use iced::{Element, Task};
+
+use crate::{ModuleEffect, Wire};
+
+/// A bar module. Object-safe; modules live in a `BTreeMap` keyed by id. The
+/// `Wire` boundary keeps the app ignorant of each module's message enum —
+/// the module downcasts whatever arrives.
+pub trait BarModule: Send {
+    fn id(&self) -> &'static str;
+
+    /// Bar contents. When `window_id` is `Some`, this is the module's popup
+    /// surface and the module returns its popup contents instead.
+    fn view(&self, window_id: Option<window::Id>) -> Element<'_, Wire>;
+
+    /// Handles a routed message; may return app-level tasks (e.g. popups).
+    fn update(&mut self, msg: Wire) -> Task<ModuleEffect>;
+
+    /// What services this module wants.
+    fn services(&self) -> Vec<crate::Service>;
+
+    /// Requested popup size when it's not the generic small menu.
+    fn popup_size(&self) -> Option<(u32, u32)> {
+        None
+    }
+
+    /// Digest config from `module.{module-id}`. Error is boxed because this
+    /// runs through `dyn BarModule`; each impl keeps its own concrete error
+    /// internally and may surface it pre-box via its constructor instead.
+    fn config(&mut self, _config: toml::Table) -> Result<(), Box<dyn Error>> {
+        Ok(())
+    }
+}

crates/common/src/reusable_elements.rs

@@ -0,0 +1,15 @@
+use iced::{border, widget::container, Theme};
+
+const REF_RADIUS: f32 = 3.5;
+
+/// The quickshell pill: rounded, filled with the theme background (the
+/// darkest colour the palette offers) so it reads as a solid block over the
+/// transparent bar.
+pub fn pill(theme: &Theme) -> container::Style {
+    container::Style {
+        background: Some(theme.palette().background.into()),
+        text_color: Some(theme.palette().text),
+        border: border::rounded(REF_RADIUS),
+        ..container::Style::default()
+    }
+}

crates/common/src/service.rs

@@ -0,0 +1,5 @@
+/// Opaque route key identifying a service subscription. Services name their
+/// own keys, so `common` never enumerates them and adding a service never
+/// edits this crate.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub struct Service(pub &'static str);

crates/common/src/wire.rs

@@ -0,0 +1,151 @@
+use std::any::Any;
+use std::fmt;
+use std::hash::{Hash, Hasher};
+use std::sync::{Arc, Mutex};
+
+use iced::futures::channel::mpsc;
+
+/// Which namespace an endpoint lives in. Module ids and service route keys
+/// are separate namespaces, so a module and a service may share a name.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum Namespace {
+    Module,
+    Service,
+}
+
+/// A wire's sender: a module id or a service route key.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub struct Endpoint {
+    pub ns: Namespace,
+    pub name: &'static str,
+}
+
+impl Endpoint {
+    pub const fn module(name: &'static str) -> Self {
+        Self {
+            ns: Namespace::Module,
+            name,
+        }
+    }
+
+    pub const fn service(name: &'static str) -> Self {
+        Self {
+            ns: Namespace::Service,
+            name,
+        }
+    }
+}
+
+/// Where a wire goes. Core owns the routing rule for each variant.
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum Target {
+    /// One module, by id.
+    Module(&'static str),
+    /// One running service's inbox, by route key.
+    Service(&'static str),
+    /// Every module subscribed to a route key (a service's fan-out).
+    Topic(&'static str),
+}
+
+/// One typed message on the wire. Core routes by `to`; the receiver
+/// downcasts `payload` to one of *its own* types. Sender and receiver keep
+/// their own concrete types — nothing here enumerates them.
+#[derive(Clone)]
+pub struct Wire {
+    pub from: Endpoint,
+    pub to: Target,
+    pub payload: Arc<dyn Any + Send + Sync>,
+}
+
+impl Wire {
+    /// A module-local message: addressed straight back to one module.
+    pub fn module<T: Any + Send + Sync>(from: Endpoint, id: &'static str, msg: T) -> Self {
+        Self {
+            from,
+            to: Target::Module(id),
+            payload: Arc::new(msg),
+        }
+    }
+
+    /// Sent into a service's inbox.
+    pub fn service<T: Any + Send + Sync>(from: Endpoint, key: &'static str, msg: T) -> Self {
+        Self {
+            from,
+            to: Target::Service(key),
+            payload: Arc::new(msg),
+        }
+    }
+
+    /// Published by a service to every module subscribed to `key`.
+    pub fn topic<T: Any + Send + Sync>(from: Endpoint, key: &'static str, msg: T) -> Self {
+        Self {
+            from,
+            to: Target::Topic(key),
+            payload: Arc::new(msg),
+        }
+    }
+
+    /// Downcasts to the receiver's own message type.
+    pub fn downcast<T: Any + Send + Sync>(&self) -> Option<&T> {
+        self.payload.downcast_ref()
+    }
+}
+
+impl fmt::Debug for Wire {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Wire")
+            .field("from", &self.from)
+            .field("to", &self.to)
+            .field("payload", &self.payload.type_id())
+            .finish()
+    }
+}
+
+/// A service's inbound mailbox: modules send `Wire`s here, the service's
+/// subscription task reads them. Cloneable; the receiver is taken once.
+///
+/// The `Arc<Mutex<Option<..>>>` lets `Bar` keep a clone and hand the same
+/// value to `Subscription::run_with` on every rebuild without moving the
+/// single-consumer receiver out of its reach.
+#[derive(Clone)]
+pub struct Inbox {
+    key: &'static str,
+    tx: mpsc::UnboundedSender<Wire>,
+    rx: Arc<Mutex<Option<mpsc::UnboundedReceiver<Wire>>>>,
+}
+
+impl Inbox {
+    /// Creates the channel backing a service's inbox.
+    pub fn new(key: &'static str) -> Self {
+        let (tx, rx) = mpsc::unbounded();
+        Self {
+            key,
+            tx,
+            rx: Arc::new(Mutex::new(Some(rx))),
+        }
+    }
+
+    /// The service's route key, used as the `Topic` it publishes under.
+    pub fn key(&self) -> &'static str {
+        self.key
+    }
+
+    /// Sends a wire into the service; `false` if the service is gone.
+    pub fn send(&self, wire: Wire) -> bool {
+        self.tx.unbounded_send(wire).is_ok()
+    }
+
+    /// Takes the receiver; the service stream calls this once, when iced
+    /// first starts it.
+    pub fn take(&self) -> Option<mpsc::UnboundedReceiver<Wire>> {
+        self.rx.lock().unwrap().take()
+    }
+}
+
+impl Hash for Inbox {
+    /// Identity for `Subscription::run_with`: the route key, so returning
+    /// the same service subscription each pass does not restart its stream.
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.key.hash(state);
+    }
+}

crates/core/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "core"
+version.workspace = true
+edition.workspace = true
+
+[[bin]]
+name = "core"
+
+[dependencies]
+common = { path = "../common" }
+iced = { workspace = true }
+iced_layershell = { workspace = true }
+tokio = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }
+chrono = { workspace = true }
+clap = {workspace = true}
+toml = {workspace =true}
+serde = { workspace = true }
+serde_yaml = { workspace = true }
+# Modules + services
+modules = { path = "../modules" }
+services = { path = "../services" }

crates/core/src/app.rs

@@ -0,0 +1,69 @@
+use std::collections::{BTreeMap, BTreeSet};
+
+use iced::window;
+
+use common::{BarModule, Inbox, Modules, Service};
+use toml::Table;
+
+/// Application state: module registry, routing, popup bookkeeping.
+pub(crate) struct Bar {
+    /// Module whose popup is open; None = closed.
+    pub(crate) active_popup: Option<String>,
+    /// Module registry keyed by stable module id.
+    pub(crate) modules: BTreeMap<&'static str, Box<dyn BarModule>>,
+    /// Left, Middle, Right ; Module Order
+    pub(crate) order: (Vec<Modules>, Vec<Modules>, Vec<Modules>),
+    /// Left/right padding between the bar edge and its content.
+    pub(crate) padding: f32,
+    /// Gap between modules in the bar.
+    pub(crate) spacing: f32,
+    /// Surface id of the open popup.
+    pub(crate) popup_id: Option<window::Id>,
+    /// Fan-out routing table: module id -> services it wants.
+    pub(crate) routes: BTreeMap<&'static str, Vec<Service>>,
+    /// One inbound mailbox per running service, keyed by route key. Modules
+    /// send here (`Target::Service`) to talk to a running service.
+    pub(crate) inputs: BTreeMap<&'static str, Inbox>,
+}
+
+impl Bar {
+    pub(crate) fn new(
+        modules_config_table: &Table,
+        modules_order: (Vec<Modules>, Vec<Modules>, Vec<Modules>),
+        padding: f32,
+        spacing: f32,
+    ) -> Self {
+        // Registry owns construction: adding a module never edits this file.
+        let modules: BTreeMap<&'static str, Box<dyn BarModule>> =
+            modules::all(modules_config_table.clone())
+                .into_iter()
+                .map(|m| (m.id(), m))
+                .collect();
+        let routes: BTreeMap<&'static str, Vec<Service>> = modules
+            .iter()
+            .map(|(id, module)| (*id, module.services()))
+            .collect();
+        // One inbox per distinct service any module wants.
+        let wanted: BTreeSet<&'static str> = routes.values().flatten().map(|s| s.0).collect();
+        tracing::debug!(?routes, "module routes: wanted msg types per module");
+        let inputs: BTreeMap<&'static str, Inbox> = wanted
+            .into_iter()
+            .map(|key| (key, Inbox::new(key)))
+            .collect();
+        tracing::debug!(
+            modules = modules.len(),
+            services = ?inputs.keys().copied().collect::<Vec<_>>(),
+            "spawning wanted services"
+        );
+        Self {
+            active_popup: None,
+            modules,
+            order: modules_order,
+            padding,
+            spacing,
+            popup_id: None,
+            routes,
+            inputs,
+        }
+    }
+}

crates/core/src/args.rs

@@ -0,0 +1,10 @@
+use clap::Parser;
+use std::path::PathBuf;
+
+#[derive(Parser)]
+pub struct Args {
+    #[arg(short, long)]
+    pub config: PathBuf,
+    // #[arg(long)]
+    // demo: bool,
+}

crates/core/src/main.rs

@@ -0,0 +1,87 @@
+//! barbar — a Wayland layer-shell status bar (iced + iced_layershell).
+//!
+//! Renders a full-width bar pinned to the top of the screen via
+//! `wlr-layer-shell`. Optional first CLI arg = target output name.
+//! Clicking a module's button spawns a LayerShell popup anchored to it.
+
+use std::fs::File;
+use std::io::Read;
+
+use clap::Parser;
+use common::BarbarConfig;
+use iced_layershell::daemon;
+
+mod app;
+mod args;
+mod msg;
+mod popup;
+mod subscription;
+mod theme;
+mod update;
+mod view;
+
+pub(crate) use app::Bar;
+pub(crate) use msg::{Message, Msg};
+
+/// Default log filter per build profile. Debug builds log barbar's own crates
+/// at `debug` while dependency noise (iced_layershell/sctk/cosmic_text/wgpu…)
+/// stays at `warn`; release builds log `warn` and above. `RUST_LOG` overrides.
+const DEFAULT_FILTER: &str = if cfg!(debug_assertions) {
+    "warn,core=debug,common=debug,modules=debug,services=debug"
+} else {
+    "warn"
+};
+
+fn main() -> Result<(), iced_layershell::Error> {
+    let filter = tracing_subscriber::EnvFilter::try_from_default_env()
+        .unwrap_or_else(|_| tracing_subscriber::EnvFilter::new(DEFAULT_FILTER));
+    tracing_subscriber::fmt().with_env_filter(filter).init();
+
+    let args = args::Args::parse();
+    tracing::debug!(config = %args.config.display(), "parsed args");
+
+    let config_handle = File::open(&args.config);
+    let config: BarbarConfig;
+    if let Ok(mut config_file) = config_handle {
+        let mut string = String::new();
+        config_file.read_to_string(&mut string).unwrap();
+        config = toml::from_str(&string).unwrap();
+        tracing::info!(config = %args.config.display(), "config loaded");
+    } else {
+        tracing::warn!(config = %args.config.display(), "cannot open config file");
+        return Ok(());
+    }
+
+    let modules = config.modules.clone().unwrap_or_default();
+    let order = config.order;
+    let disp = config.display;
+    tracing::info!(monitor = ?disp.monitor, "starting barbar daemon");
+    let (padding, spacing) = (disp.padding, disp.spacing);
+    let settings = disp.settings();
+
+    // Optional base16 theme; `None` lets iced follow the system colour scheme.
+    let theme = disp.theme.as_deref().map(theme::load);
+
+    daemon(
+        move || {
+            Bar::new(
+                &modules,
+                (
+                    order.left.clone(),
+                    order.middle.clone(),
+                    order.right.clone(),
+                ),
+                padding,
+                spacing,
+            )
+        },
+        subscription::namespace,
+        update::update,
+        view::view,
+    )
+    .style(view::style)
+    .theme(move |_: &Bar, _: iced::window::Id| theme.clone())
+    .subscription(subscription::gather_subscriptions)
+    .settings(settings)
+    .run()
+}

crates/core/src/msg.rs

@@ -0,0 +1,35 @@
+use iced::window;
+use iced_layershell::to_layer_message;
+
+use common::{ModuleEffect, Wire};
+
+/// Synchronous input: wires plus window events.
+#[derive(Debug, Clone)]
+pub(crate) enum Msg {
+    /// One wire; core dispatches by its `to` target.
+    Wire(Wire),
+    /// The compositor confirmed a window closed. The popup is really gone.
+    WindowClosed(window::Id),
+}
+
+/// iced needs one `Message` type. `to_layer_message` must sit here: it
+/// injects the layer-shell effect variants + their `TryInto` impl.
+#[to_layer_message(multi)]
+#[derive(Debug, Clone)]
+pub(crate) enum Message {
+    Event(Msg),
+    /// Effects. `common::ModuleEffect` is the one effect vocabulary, so
+    /// mapping module output is a plain `.map(Message::Effect)`.
+    Effect(ModuleEffect),
+}
+
+/// `to_layer_message` generates `popup_open` as a fn private to this module;
+/// re-expose it for the popup surface code, which lives elsewhere.
+pub(crate) fn popup_open(
+    settings: iced_layershell::actions::IcedNewPopupSettings,
+) -> (
+    iced_layershell::reexport::IcedId,
+    iced_layershell::reexport::Task<Message>,
+) {
+    Message::popup_open(settings)
+}

crates/core/src/popup.rs

@@ -0,0 +1,138 @@
+//! Popup surfaces: bounds capture, open/close, and rendering.
+//!
+//! A popup is a separate LayerShell surface anchored to its module's button.
+//! The app captures the button's laid-out bounds via a widget-tree operation,
+//! then opens the popup there; the active module renders its content.
+
+use iced::advanced::widget as advanced_widget;
+use iced::widget::{column, container, text};
+use iced::{Border, Element, Padding, Rectangle, Task};
+use iced_layershell::actions::IcedNewPopupSettings;
+use iced_layershell::reexport::{PopupAnchor, PopupGravity};
+
+use common::{ModuleEffect, PopupSettings};
+
+use crate::msg::popup_open;
+use crate::{Bar, Message, Msg};
+
+/// Default (small menu) popup size.
+const POPUP_W: u32 = 150;
+const POPUP_H: u32 = 100;
+
+// Gap (logical px) between the bar's bottom edge and the popup.
+// const POPUP_GAP: i32 = 32;
+
+/// Opens a popup for `module_id` below its laid-out `bounds`. Size comes
+/// from the module's `popup_size()` (default: small menu).
+pub fn open_popup(bar: &mut Bar, bounds: Rectangle, settings: PopupSettings) -> Task<Message> {
+    bar.active_popup = Some(settings.module_id.clone());
+
+    let (w, h) = bar
+        .modules
+        .get(settings.module_id.as_str())
+        .and_then(|m| m.popup_size())
+        .unwrap_or((POPUP_W, POPUP_H));
+
+    // Anchor at the button's bottom edge + POPUP_GAP so the popup grows
+    // downward from just below the bar.
+    let (bx, by, bw, bh) = (
+        bounds.x.round() as i32,
+        bounds.y.round() as i32,
+        bounds.width.round() as i32,
+        bounds.height.round() as i32,
+    );
+    let anchor_rect = (bx, by, bw, bh + settings.gap);
+    let settings_popup = IcedNewPopupSettings::on_current_surface((w, h), anchor_rect)
+        .anchor(PopupAnchor::Bottom)
+        .gravity(PopupGravity::Bottom);
+
+    let (id, task) = popup_open(settings_popup);
+    bar.popup_id = Some(id);
+    tracing::debug!(module = %settings.module_id, ?id, size = ?(w, h), "popup opened");
+    task
+}
+
+/// Requests closing the popup. Does not clear popup state — that happens on
+/// `Msg::WindowClosed`, so popup content keeps rendering until then.
+pub fn close_popup(bar: &mut Bar) -> Task<Message> {
+    if let Some(id) = bar.popup_id {
+        tracing::debug!(?id, "requesting popup close");
+        return Task::done(Message::Effect(ModuleEffect::ClosePopup(id)));
+    }
+    Task::none()
+}
+
+/// Runs a widget-tree [`Operation`] that captures the laid-out bounds of the
+/// given element, then reports them via `BoundsFound` for the module.
+pub fn capture_bounds(settings: PopupSettings) -> Task<Message> {
+    let target = iced::widget::Id::from(settings.element_id.clone());
+
+    struct FindBounds {
+        target: iced::widget::Id,
+        found: Option<Rectangle>,
+    }
+
+    impl advanced_widget::Operation<Rectangle> for FindBounds {
+        fn traverse(
+            &mut self,
+            operate: &mut dyn FnMut(&mut dyn advanced_widget::Operation<Rectangle>),
+        ) {
+            operate(self);
+        }
+
+        fn container(&mut self, id: Option<&iced::widget::Id>, bounds: Rectangle) {
+            if self.found.is_none() && id == Some(&self.target) {
+                self.found = Some(bounds);
+            }
+        }
+
+        fn finish(&self) -> advanced_widget::operation::Outcome<Rectangle> {
+            match self.found {
+                Some(bounds) => advanced_widget::operation::Outcome::Some(bounds),
+                None => advanced_widget::operation::Outcome::None,
+            }
+        }
+    }
+
+    advanced_widget::operate(FindBounds {
+        target,
+        found: None,
+    })
+    .map(move |bounds| -> Message {
+        Message::Effect(ModuleEffect::BoundsFound(bounds, settings.clone()))
+    })
+}
+
+/// Popup widget tree on its own LayerShell surface; the active module
+/// renders its content via `view(Some(id))`.
+pub fn view(bar: &Bar) -> Element<'_, Message> {
+    let module_id = bar.active_popup.as_deref().unwrap();
+    let popup_id = bar.popup_id.unwrap();
+    let content = bar
+        .modules
+        .get(module_id)
+        .map(|module| {
+            module
+                .view(Some(popup_id))
+                .map(|w| Message::Event(Msg::Wire(w)))
+        })
+        .unwrap_or_else(|| text("unknown module").into());
+
+    container(column![content,].spacing(1))
+        .padding(Padding::from(4))
+        .style(|theme| container::Style {
+            text_color: None,
+            background: Some(
+                iced::Background::Color(theme.extended_palette().background.base.color)
+                    .scale_alpha(0.4),
+            ),
+            border: Border {
+                width: 3.0,
+                radius: 10.into(),
+                color: theme.extended_palette().secondary.strong.color,
+            },
+            snap: true,
+            ..Default::default()
+        })
+        .into()
+}

crates/core/src/subscription.rs

@@ -0,0 +1,28 @@
+use iced::{window, Subscription};
+
+use common::Service;
+use services::IntoSubscription;
+
+use crate::app::Bar;
+use crate::msg::{Message, Msg};
+
+pub(crate) fn namespace() -> String {
+    String::from("barbar")
+}
+
+/// Route subscriptions + window-close events (popup really destroyed).
+/// One subscription per service inbox, so adding a service never edits this.
+pub(crate) fn gather_subscriptions(bar: &Bar) -> Subscription<Message> {
+    let route_sub = Subscription::batch(
+        bar.inputs
+            .iter()
+            .map(|(&key, inbox)| {
+                Service(key)
+                    .into_subscription(inbox.clone())
+                    .map(|wire| Message::Event(Msg::Wire(wire)))
+            })
+            .collect::<Vec<_>>(),
+    );
+    let close_events = window::close_events().map(|id| Message::Event(Msg::WindowClosed(id)));
+    Subscription::batch(vec![route_sub, close_events])
+}

crates/core/src/theme.rs

@@ -0,0 +1,60 @@
+//! Base16 (`base00`..`base0F`) scheme loaded from YAML into an iced [`Theme`].
+//!
+//! The sixteen slots map onto iced's six-colour [`Palette`]: `base00` is the
+//! background, `base05` the foreground, and the blue/green/yellow/red accents
+//! become primary/success/warning/danger. The remaining slots are unused.
+
+use std::path::Path;
+
+use iced::theme::Palette;
+use iced::{Color, Theme};
+use serde::Deserialize;
+
+/// The base16 slots the palette needs; other keys (author, base01..) are
+/// ignored by serde.
+#[derive(Deserialize)]
+struct Base16 {
+    scheme: Option<String>,
+    base00: String,
+    base05: String,
+    base08: String,
+    #[serde(rename = "base0A")]
+    base0a: String,
+    #[serde(rename = "base0B")]
+    base0b: String,
+    #[serde(rename = "base0D")]
+    base0d: String,
+}
+
+impl Base16 {
+    fn into_theme(self) -> Theme {
+        Theme::custom(
+            self.scheme.unwrap_or_else(|| "base16".to_string()),
+            Palette {
+                background: hex(&self.base00),
+                text: hex(&self.base05),
+                primary: hex(&self.base0d),
+                success: hex(&self.base0b),
+                warning: hex(&self.base0a),
+                danger: hex(&self.base08),
+            },
+        )
+    }
+}
+
+/// `"RRGGBB"` (optionally `#`-prefixed) to a [`Color`].
+fn hex(s: &str) -> Color {
+    let v = u32::from_str_radix(s.trim_start_matches('#'), 16)
+        .unwrap_or_else(|_| panic!("base16 colour {s:?} is not RRGGBB hex"));
+    Color::from_rgb8((v >> 16) as u8, (v >> 8) as u8, v as u8)
+}
+
+/// Loads a base16 YAML scheme; panics with the offending path on a read or
+/// parse error, matching how the TOML config is loaded.
+pub fn load(path: &Path) -> Theme {
+    let text = std::fs::read_to_string(path)
+        .unwrap_or_else(|e| panic!("cannot read theme {}: {e}", path.display()));
+    let scheme: Base16 = serde_yaml::from_str(&text)
+        .unwrap_or_else(|e| panic!("cannot parse base16 theme {}: {e}", path.display()));
+    scheme.into_theme()
+}

crates/core/src/update.rs

@@ -0,0 +1,102 @@
+use iced::Task;
+
+use common::{ModuleEffect, Service, Target, Wire};
+
+use crate::app::Bar;
+use crate::msg::{Message, Msg};
+use crate::popup;
+
+pub(crate) fn update(bar: &mut Bar, msg: Message) -> Task<Message> {
+    match msg {
+        Message::Event(event) => handle_event(bar, event),
+        Message::Effect(effect) => handle_effect(bar, effect),
+        // Layer-shell variants injected by `to_layer_message`.
+        _ => Task::none(),
+    }
+}
+
+/// Applies an input event to state; effects come back as `Task`s.
+fn handle_event(bar: &mut Bar, event: Msg) -> Task<Message> {
+    match event {
+        Msg::Wire(wire) => route(bar, wire),
+
+        Msg::WindowClosed(id) => {
+            // Popup gone; forget it. `popup_id` stays set until this event
+            // so the popup content (not the bar) renders during teardown.
+            if bar.popup_id == Some(id) {
+                bar.popup_id = None;
+                bar.active_popup = None;
+                tracing::debug!(?id, "popup window closed");
+            }
+            Task::none()
+        }
+    }
+}
+
+/// Delivers a wire by its target — the only place routing lives.
+fn route(bar: &mut Bar, wire: Wire) -> Task<Message> {
+    match wire.to {
+        Target::Module(id) => match bar.modules.get_mut(id) {
+            Some(module) => module.update(wire).map(Message::Effect),
+            None => {
+                tracing::warn!(module = id, "wire routed to unknown module");
+                Task::none()
+            }
+        },
+
+        Target::Service(key) => {
+            if let Some(inbox) = bar.inputs.get(key) {
+                if !inbox.send(wire) {
+                    tracing::warn!(service = key, "service inbox closed");
+                }
+            } else {
+                tracing::warn!(service = key, "wire routed to unknown service");
+            }
+            Task::none()
+        }
+
+        Target::Topic(key) => {
+            // Fan out by route key; the payload is opaque here, each module
+            // downcasts it. New services never touch this file.
+            let topic = Service(key);
+            let tasks: Vec<_> = bar
+                .modules
+                .iter_mut()
+                .filter(|(id, _)| {
+                    bar.routes
+                        .get(*id)
+                        .is_some_and(|keys| keys.contains(&topic))
+                })
+                .map(|(_, module)| module.update(wire.clone()).map(Message::Effect))
+                .collect();
+            tracing::debug!(topic = key, subscribers = tasks.len(), "fan-out");
+            tasks.into_iter().fold(Task::none(), |acc, t| acc.chain(t))
+        }
+    }
+}
+
+/// Runs an effect; may set up bar state for it (e.g. which popup is open).
+fn handle_effect(bar: &mut Bar, effect: ModuleEffect) -> Task<Message> {
+    match effect {
+        ModuleEffect::RequestPopup(settings) => {
+            // Toggle: close if already open for this module, else open.
+            if bar.active_popup.as_deref() == Some(settings.module_id.as_str()) {
+                tracing::debug!(module = settings.module_id, "closing popup");
+                popup::close_popup(bar)
+            } else {
+                tracing::debug!(module = settings.module_id, "opening popup");
+                popup::capture_bounds(settings)
+            }
+        }
+
+        ModuleEffect::BoundsFound(bounds, settings) => popup::open_popup(bar, bounds, settings),
+
+        ModuleEffect::ClosePopup(id) => {
+            // Request removal only; keep popup state so the popup content
+            // renders until `WindowClosed` confirms it's gone.
+            Task::done(Message::RemoveWindow(id))
+        }
+
+        ModuleEffect::Send(wire) => route(bar, wire),
+    }
+}

crates/core/src/view.rs

@@ -0,0 +1,95 @@
+use iced::widget::{container, row, space};
+use iced::{window, Alignment, Element, Length, Theme};
+
+use crate::app::Bar;
+use crate::msg::{Message, Msg};
+use crate::popup;
+
+pub(crate) fn view(bar: &Bar, id: window::Id) -> Element<'_, Message> {
+    if bar.popup_id == Some(id) {
+        popup::view(bar) // popup surface
+    } else {
+        bar_view(bar) // main bar surface
+    }
+}
+
+/// Each module renders itself; the bar lays them out in a row.
+fn bar_view(bar: &Bar) -> Element<'_, Message> {
+    // for (i, (_, module)) in bar.modules.iter().enumerate() {
+    //     children.push(module.view(None).map(|w| Message::Event(Msg::Wire(w))));
+    //     if i < bar.modules.len() - 1 {
+    //         children.push(text("|").size(14).into());
+    //     }
+    // }
+    let left = row(bar
+        .order
+        .0
+        .iter()
+        .map(|x| {
+            bar.modules
+                .get(x.to_string())
+                .unwrap()
+                .view(None)
+                .map(|w| Message::Event(Msg::Wire(w)))
+        })
+        .collect::<Vec<Element<Message>>>())
+    .spacing(bar.spacing)
+    .width(Length::Shrink)
+    .align_y(Alignment::Center);
+
+    let middle = row(bar
+        .order
+        .1
+        .iter()
+        .map(|x| {
+            bar.modules
+                .get(x.to_string())
+                .unwrap()
+                .view(None)
+                .map(|w| Message::Event(Msg::Wire(w)))
+        })
+        .collect::<Vec<Element<Message>>>())
+    .spacing(bar.spacing)
+    .width(Length::Shrink)
+    .align_y(Alignment::Center);
+    let right = row(bar
+        .order
+        .2
+        .iter()
+        .map(|x| {
+            bar.modules
+                .get(x.to_string())
+                .unwrap()
+                .view(None)
+                .map(|w| Message::Event(Msg::Wire(w)))
+        })
+        .collect::<Vec<Element<Message>>>())
+    .spacing(bar.spacing)
+    .width(Length::Shrink)
+    .align_y(Alignment::Center);
+
+    let row = row![
+        left,
+        space::horizontal(),
+        middle,
+        space::horizontal(),
+        right,
+    ]
+    .width(Length::Fill)
+    .align_y(Alignment::Center);
+
+    container(row)
+        .padding([0.0, bar.padding])
+        .width(Length::Fill)
+        .height(Length::Fill)
+        .align_y(Alignment::Center)
+        .into()
+}
+
+pub(crate) fn style(_bar: &Bar, theme: &Theme) -> iced::theme::Style {
+    use iced::theme::Style;
+    Style {
+        background_color: iced::Color::TRANSPARENT,
+        text_color: theme.palette().text,
+    }
+}

crates/modules/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "modules"
+version.workspace = true
+edition.workspace = true
+
+[lib]
+name = "modules"
+path = "src/lib.rs"
+
+[dependencies]
+common = { path = "../common" }
+iced = { workspace = true }
+thiserror = { workspace = true }
+tracing = { workspace = true }
+chrono = { workspace = true }
+toml = { workspace = true }
+serde = {workspace = true}

crates/modules/README.md

@@ -0,0 +1,110 @@
+# modules
+
+Bar modules. Each module renders a piece of the bar (or its popup) and is
+object-safe behind `common::BarModule`, so core holds them as
+`Box<dyn BarModule>` and never knows their message types — everything crosses
+the `common::Wire` boundary.
+
+Message types are shared, so they live in the `common` crate, under
+`common/src/messages/modules/`. That is what lets a module and core name the
+same payload without either depending on the other.
+
+## Getting started: add a module
+
+1. Declare the module's messages in `crates/common/src/messages/modules/greeter.rs`:
+
+```rust
+//! Greeter module messages.
+
+#[derive(Clone)]
+pub enum GreeterMsg {
+    Poke,
+}
+```
+
+2. Re-export them from `crates/common/src/messages/modules/mod.rs`:
+
+```rust
+mod clock;
+mod greeter;
+
+pub use clock::ClockMsg;
+pub use greeter::GreeterMsg;
+```
+
+3. Create `crates/modules/src/greeter.rs`:
+
+```rust
+use std::error::Error;
+
+use iced::widget::text;
+use iced::{Element, Task};
+
+use common::{BarModule, Endpoint, GreeterMsg, ModuleEffect, Service, Wire};
+
+pub struct Greeter {
+    text: String,
+}
+
+impl Default for Greeter {
+    fn default() -> Self {
+        Self { text: "hi".into() }
+    }
+}
+
+impl BarModule for Greeter {
+    fn id(&self) -> &'static str {
+        "greeter"
+    }
+
+    fn view(&self, _window_id: Option<iced::window::Id>) -> Element<'_, Wire> {
+        text(&self.text).into()
+    }
+
+    fn update(&mut self, msg: Wire) -> Task<ModuleEffect> {
+        match msg.downcast::<GreeterMsg>() {
+            Some(GreeterMsg::Poke) => {
+                self.text = "poked".into();
+                Task::none()
+            }
+            None => Task::none(),
+        }
+    }
+
+    /// Route keys this module subscribes to.
+    fn services(&self) -> Vec<Service> {
+        Vec::new(
+    }
+
+    /// Optional: read `module.greeter` from the config table.
+    fn config(&mut self, _config: toml::Table) -> Result<(), Box<dyn Error>> {
+        Ok(())
+    }
+}
+```
+
+4. Register it in `crates/modules/src/lib.rs`'s `all()` and re-export it:
+
+```rust
+mod greeter;
+pub use greeter::Greeter;
+
+pub fn all(module_config: toml::Table) -> Vec<Box<dyn BarModule>> {
+    vec![
+        Box::new(clock::Clock::new(Some(module_config.clone()))),
+        Box::new(greeter::Greeter::default()),
+    ]
+}
+```
+
+That's it — core picks it up by `id()`. Use `wire` targeting:
+
+```rust
+// Module-local message back to yourself:
+Wire::module(Endpoint::module(self.id()), self.id(), GreeterMsg::Poke)
+```
+
+To talk to a service, add it to `services()` and send via
+`Wire::service(...)`; service ticks arrive in `update()` and you `downcast`
+to the payload type (e.g. `common::ClockPayload`). See `src/clock.rs` for a
+full example.

crates/modules/src/audio.rs

@@ -0,0 +1,93 @@
+//! Audio module: the default sink and source as icons, drawn only while
+//! something is muted — the signal the quickshell Audio widget gives.
+
+use iced::widget::{container, row, space, text};
+use iced::{Alignment, Element, Length, Task};
+
+use common::{pill, AudioNode, BarModule, ModuleEffect, PipewireMsg, PipewireState, Service, Wire};
+
+/// Glyphs exactly as the Quickshell Audio widget draws them: the speaker is a
+/// Material `md-volume` icon, the mic a Font Awesome one.
+const SINK_ON: &str = "\u{f057e}"; // md-volume_high
+const SINK_MUTED: &str = "\u{f0581}"; // md-volume_off
+const MIC_ON: &str = "\u{f130}"; // fa-microphone
+const MIC_MUTED: &str = "\u{f131}"; // fa-microphone_slash
+
+/// Quickshell's geometry at its 20 px reference bar: a 24 px slot per icon
+/// and 4 px between them. Heights and the pill fill the bar through layout,
+/// but font size is a fixed px value iced cannot derive from the space it is
+/// given — if the bar ever leaves 20 px, scale the two sizes here.
+const REF_SLOT_W: f32 = 24.0;
+const REF_SPACING: f32 = 4.0;
+/// The speaker is re-drawn in the mono face, whose ink is 1168/1496 the size
+/// of the proportional face quickshell uses, so it is pre-compensated.
+const REF_SINK_SIZE: f32 = 20.0 * 1496.0 / 1168.0;
+const REF_MIC_SIZE: f32 = 30.0;
+
+pub struct Audio {
+    state: PipewireState,
+}
+
+impl Audio {
+    pub fn new() -> Self {
+        Self {
+            state: PipewireState::default(),
+        }
+    }
+}
+
+impl BarModule for Audio {
+    fn id(&self) -> &'static str {
+        "audio"
+    }
+
+    fn view(&self, _window_id: Option<iced::window::Id>) -> Element<'_, Wire> {
+        let (sink, source) = (self.state.sink, self.state.source);
+        if !sink.muted && !source.muted {
+            // Nothing is muted, so there is nothing to show.
+            return space::horizontal().into();
+        }
+
+        let icons = row![
+            icon(glyph(sink, SINK_ON, SINK_MUTED), REF_SINK_SIZE),
+            icon(glyph(source, MIC_ON, MIC_MUTED), REF_MIC_SIZE),
+        ]
+        .height(Length::Fill)
+        .spacing(REF_SPACING);
+
+        container(icons).height(Length::Fill).style(pill).into()
+    }
+
+    fn update(&mut self, msg: Wire) -> Task<ModuleEffect> {
+        if let Some(state) = msg.downcast::<PipewireState>() {
+            self.state = *state;
+        }
+        Task::none()
+    }
+
+    fn services(&self) -> Vec<Service> {
+        vec![PipewireMsg::State.key()]
+    }
+}
+
+/// One glyph centred in a fixed-width slot that fills the bar's height.
+fn icon<'a>(glyph: &'static str, size: f32) -> Element<'a, Wire> {
+    container(
+        text(glyph)
+            .size(size)
+            .height(Length::Fill)
+            .align_y(Alignment::Center),
+    )
+    .center_x(Length::Fixed(REF_SLOT_W))
+    .height(Length::Fill)
+    .into()
+}
+
+/// The muted glyph when the node is muted, its normal glyph otherwise.
+fn glyph(node: AudioNode, on: &'static str, muted: &'static str) -> &'static str {
+    if node.muted {
+        muted
+    } else {
+        on
+    }
+}

crates/modules/src/battery.rs

@@ -0,0 +1,274 @@
+//! Battery module: Android-style battery icon fed by the battery service.
+
+use iced::widget::{column, container, mouse_area, row, stack, text};
+use iced::{alignment, Border, Color, Element, Length, Task, Theme};
+
+use common::{
+    pill, BarModule, BatteryAction, BatteryEvent, BatteryMsg, BatteryStatus, Endpoint,
+    ModuleEffect, PopupSettings, Service, Wire,
+};
+use serde::Deserialize;
+use toml::Table;
+
+/// Icon shell size (logical px); fill scales inside it.
+const SHELL_W: f32 = 28.0;
+const SHELL_H: f32 = 14.0;
+const BORDER_W: f32 = 1.5;
+const PAD: f32 = 2.0;
+/// Charge at or below this shows the warning color while discharging.
+const LOW_PCT: i32 = 20;
+
+pub struct Battery {
+    percent: Option<i32>,
+    status: BatteryStatus,
+    eta_secs: Option<u64>,
+    numbers_in_icon: bool,
+}
+
+/// Battery info popup size (logical px).
+const POPUP_W: u32 = 280;
+const POPUP_H: u32 = 160;
+
+/// `module.battery` table; everything optional.
+#[derive(Deserialize, Default)]
+struct BatteryConfig {
+    /// Render the percentage as a number centered inside the icon shell.
+    #[serde(default)]
+    numbers_in_icon: bool,
+}
+
+impl Battery {
+    pub fn new(config: Option<Table>) -> Self {
+        Self {
+            percent: None,
+            status: BatteryStatus::default(),
+            eta_secs: None,
+            numbers_in_icon: config
+                .and_then(|table| table.get("battery").cloned())
+                .and_then(|battery| battery.try_into().ok())
+                .map(|cfg: BatteryConfig| cfg.numbers_in_icon)
+                .unwrap_or_default(),
+        }
+    }
+
+    /// Fill width for the level, leaving a sliver visible below 100%.
+    fn fill_w(&self) -> f32 {
+        match self.percent {
+            Some(p) => ((SHELL_W - 2.0 * (BORDER_W + PAD)) * p as f32 / 100.0)
+                .clamp(0.0, SHELL_W)
+                .max(if p > 0 { 2.0 } else { 0.0 }),
+            None => 0.0,
+        }
+    }
+}
+
+/// Human form of a duration: `1 h 5 min`, `42 min`, or `30 s`.
+fn fmt_duration(secs: u64) -> String {
+    let (hours, mins) = (secs / 3600, secs % 3600 / 60);
+    if hours > 0 {
+        format!("{hours} h {mins} min")
+    } else if mins > 0 {
+        format!("{mins} min")
+    } else {
+        format!("{secs} s")
+    }
+}
+
+/// Icon ink: success green while charging, danger red when low and
+/// discharging, bar text otherwise.
+fn ink(status: BatteryStatus, percent: Option<i32>, theme: &Theme) -> Color {
+    let palette = theme.palette();
+    match status {
+        BatteryStatus::Charging => palette.success,
+        BatteryStatus::Discharging if percent.is_some_and(|p| p <= LOW_PCT) => palette.danger,
+        _ => palette.text,
+    }
+}
+
+/// Transparent shell with a rounded outline tinted by charge state.
+fn shell_style(status: BatteryStatus, percent: Option<i32>) -> impl Fn(&Theme) -> container::Style {
+    move |theme: &Theme| container::Style {
+        border: Border {
+            color: ink(status, percent, theme),
+            width: BORDER_W,
+            radius: 4.0.into(),
+        },
+        ..container::Style::default()
+    }
+}
+
+/// Solid fill (and nub cap) tinted by charge state. `dim` renders the
+/// Android-style muted fill that sits behind the in-icon number.
+fn solid_style(
+    status: BatteryStatus,
+    percent: Option<i32>,
+    dim: bool,
+) -> impl Fn(&Theme) -> container::Style {
+    move |theme: &Theme| {
+        let palette = theme.palette();
+        let background = if dim {
+            Color {
+                a: 0.45,
+                ..palette.text
+            }
+        } else {
+            ink(status, percent, theme)
+        };
+        container::Style {
+            background: Some(background.into()),
+            border: Border {
+                radius: 2.0.into(),
+                ..Default::default()
+            },
+            ..container::Style::default()
+        }
+    }
+}
+
+/// Bold face of the bar font, matching Android's bold in-icon digits.
+fn bold() -> iced::Font {
+    iced::Font {
+        weight: iced::font::Weight::Bold,
+        ..iced::Font::default()
+    }
+}
+
+impl Battery {
+    /// Bar tile: icon (plus `%` label unless numbers live in the icon),
+    /// left-click opens the info popup.
+    fn bar(&self) -> Element<'_, Wire> {
+        let status = self.status;
+        let shell = container(
+            container(text(""))
+                .width(Length::Fixed(self.fill_w()))
+                .height(Length::Fill)
+                .style(solid_style(status, self.percent, self.numbers_in_icon)),
+        )
+        .width(Length::Fixed(SHELL_W))
+        .height(Length::Fixed(SHELL_H))
+        .padding(PAD)
+        .style(shell_style(status, self.percent));
+        // Optional percentage readout centered over the fill, in the frame's
+        // light color — legible on the dimmed fill, like Android.
+        let shell: Element<'_, Wire> = match (self.numbers_in_icon, self.percent) {
+            (true, Some(percent)) => stack![
+                shell,
+                container(text(format!("{percent}")).size(10).font(bold()).style(
+                    |theme: &Theme| text::Style {
+                        color: Some(theme.palette().text),
+                    }
+                ),)
+                .width(Length::Fill)
+                .height(Length::Fill)
+                .align_x(alignment::Horizontal::Center)
+                .align_y(alignment::Vertical::Center),
+            ]
+            .into(),
+            _ => shell.into(),
+        };
+        let icon = row![
+            shell,
+            // Nub cap on the right edge.
+            container(text(""))
+                .width(Length::Fixed(2.5))
+                .height(Length::Fixed(6.0))
+                .style(solid_style(status, self.percent, false)),
+        ]
+        .spacing(2)
+        .align_y(iced::Alignment::Center);
+        let bar: Element<'_, Wire> = if self.numbers_in_icon {
+            icon.into()
+        } else {
+            let label = match self.percent {
+                Some(percent) => text(format!("{percent}%")),
+                None => text("--"),
+            };
+            row![icon, label]
+                .spacing(6)
+                .align_y(iced::Alignment::Center)
+                .into()
+        };
+        // Container carries the module id so the popup can anchor to it.
+        container(mouse_area(bar).on_press(Wire::module(
+            Endpoint::module(self.id()),
+            self.id(),
+            BatteryAction::OpenPopup,
+        )))
+        .style(pill)
+        .height(Length::Fill)
+        .align_y(alignment::Vertical::Center)
+        .id(iced::widget::Id::from(self.id()))
+        .into()
+    }
+
+    /// Popup surface: charge, status, and time to full/empty.
+    fn popup(&self) -> Element<'_, Wire> {
+        let (status, percent) = (self.status, self.percent);
+        let warn = move |theme: &Theme| text::Style {
+            color: Some(ink(status, percent, theme)),
+        };
+        let charge = match percent {
+            Some(percent) => text(format!("{percent}%")).size(44).style(warn),
+            None => text("--").size(44).style(warn),
+        };
+        let status = text(match self.status {
+            BatteryStatus::Charging => "Charging".to_string(),
+            BatteryStatus::Discharging => "Discharging".to_string(),
+            BatteryStatus::Empty => "Empty".to_string(),
+            BatteryStatus::Full => "Fully charged".to_string(),
+            BatteryStatus::Unknown => "Unknown".to_string(),
+        });
+        let mut lines = column![charge, status].spacing(4);
+        if let Some(secs) = self.eta_secs {
+            let eta = match self.status {
+                BatteryStatus::Charging => format!("Full in {}", fmt_duration(secs)),
+                BatteryStatus::Discharging => format!("{} remaining", fmt_duration(secs)),
+                _ => fmt_duration(secs),
+            };
+            lines = lines.push(text(eta));
+        }
+        container(lines).padding(16).width(Length::Fill).into()
+    }
+}
+
+impl BarModule for Battery {
+    fn id(&self) -> &'static str {
+        "battery"
+    }
+
+    fn view(&self, window_id: Option<iced::window::Id>) -> Element<'_, Wire> {
+        match window_id {
+            Some(_) => self.popup(),
+            None => self.bar(),
+        }
+    }
+
+    fn update(&mut self, msg: Wire) -> Task<ModuleEffect> {
+        if let Some(event) = msg.downcast::<BatteryEvent>() {
+            match event {
+                BatteryEvent::PercentageChanged(percent) => self.percent = Some(*percent),
+                BatteryEvent::StatusChanged(status) => self.status = *status,
+                BatteryEvent::EtaChanged(eta) => self.eta_secs = *eta,
+            }
+            return Task::none();
+        }
+        match msg.downcast::<BatteryAction>() {
+            Some(BatteryAction::OpenPopup) => {
+                Task::done(ModuleEffect::RequestPopup(PopupSettings {
+                    module_id: self.id().into(),
+                    element_id: self.id().into(),
+                    gap: 8,
+                }))
+            }
+            None => Task::none(),
+        }
+    }
+
+    fn services(&self) -> Vec<Service> {
+        vec![BatteryMsg::Events.key()]
+    }
+
+    fn popup_size(&self) -> Option<(u32, u32)> {
+        Some((POPUP_W, POPUP_H))
+    }
+}

crates/modules/src/clock.rs

@@ -0,0 +1,152 @@
+//! Clock module: subscribes to the clock service, renders the time in the
+//! bar. Left-click toggles the seconds suffix — and pokes the running clock
+//! service to switch which kind it publishes; right-click opens a popup.
+
+use iced::widget::{container, mouse_area, text};
+use iced::Length::Fill;
+use iced::{alignment, Element, Padding, Task};
+
+use common::{
+    pill, BarModule, ClockKind, ClockMsg, ClockPayload, Endpoint, ModuleEffect, PopupSettings,
+    Service, Wire,
+};
+use serde::Deserialize;
+use toml::Table;
+
+/// Big-text popup size (logical px).
+const POPUP_W: u32 = 360;
+const POPUP_H: u32 = 160;
+
+/// Errors digesting the `module.clock` config table.
+#[derive(Debug, thiserror::Error)]
+pub enum ClockError {
+    /// Config value was present but not a bool.
+    #[error("module.clock.{0} must be a bool")]
+    NotBool(&'static str),
+}
+
+pub struct Clock {
+    value: String,
+    show_seconds: bool,
+}
+
+#[derive(Deserialize, Default)]
+struct ClockConfig {
+    #[serde(default)]
+    show_seconds: bool,
+}
+
+impl Clock {
+    pub fn new(config: Option<Table>) -> Self {
+        match config_clock(config) {
+            Some(x) => Self {
+                value: "--:--:--".to_string(),
+                show_seconds: x.show_seconds,
+            },
+            None => Self::default(),
+        }
+    }
+
+    /// Display string: HH:MM:SS, or HH:MM when seconds are hidden.
+    fn shown(&self) -> String {
+        if self.show_seconds {
+            self.value.clone()
+        } else {
+            self.value
+                .split(':') // [hh, mm, ss]
+                .take(2)
+                .collect::<Vec<_>>()
+                .join(":")
+        }
+    }
+}
+
+impl Default for Clock {
+    fn default() -> Self {
+        Self {
+            value: "--:--:--".to_string(),
+            show_seconds: false,
+        }
+    }
+}
+
+fn config_clock(table: Option<Table>) -> Option<ClockConfig> {
+    let clock = table?.get("clock")?.clone();
+    clock.try_into().ok()
+}
+
+impl BarModule for Clock {
+    fn id(&self) -> &'static str {
+        "clock"
+    }
+
+    fn view(&self, window_id: Option<iced::window::Id>) -> Element<'_, Wire> {
+        let me = Endpoint::module(self.id());
+        match window_id {
+            // Popup surface: current time in large text.
+            Some(_) => container(text(&self.value).size(56))
+                .align_x(alignment::Horizontal::Center)
+                .align_y(alignment::Vertical::Center)
+                .padding(20)
+                .width(Fill)
+                .into(),
+            // Bar surface: clickable time. Container carries the module id
+            // so the popup can anchor to these bounds.
+            None => container(
+                mouse_area(text(self.shown()).size(16))
+                    .on_press(Wire::module(me, self.id(), ClockMsg::ToggleSeconds))
+                    .on_right_press(Wire::module(me, self.id(), ClockMsg::OpenPopup)),
+            )
+            .style(pill)
+            .padding(Padding {
+                right: 3.0,
+                left: 3.0,
+                ..Default::default()
+            })
+            .id(iced::widget::Id::from(self.id()))
+            .into(),
+        }
+    }
+
+    fn update(&mut self, msg: Wire) -> Task<ModuleEffect> {
+        // The service publishes a raw `ClockPayload`; UI sends `ClockMsg`.
+        if let Some(payload) = msg.downcast::<ClockPayload>() {
+            self.value = match payload {
+                ClockPayload::Mins(v) | ClockPayload::Seconds(v) => v.clone(),
+            };
+            return Task::none();
+        }
+        match msg.downcast::<ClockMsg>() {
+            Some(ClockMsg::ToggleSeconds) => {
+                self.show_seconds = !self.show_seconds;
+                tracing::debug!(show_seconds = self.show_seconds, "clock toggle");
+                let want = if self.show_seconds {
+                    ClockKind::Seconds
+                } else {
+                    ClockKind::Mins
+                };
+                // Poke the running clock service: tell it which kind to publish.
+                Task::done(ModuleEffect::Send(Wire::service(
+                    Endpoint::module(self.id()),
+                    ClockKind::Seconds.key().0,
+                    want,
+                )))
+            }
+            Some(ClockMsg::OpenPopup) => Task::done(ModuleEffect::RequestPopup(PopupSettings {
+                // name: "barbar".into(),
+                module_id: self.id().into(),
+                element_id: "clock".into(),
+                gap: 8,
+            })),
+            None => Task::none(),
+        }
+    }
+
+    fn services(&self) -> Vec<Service> {
+        vec![ClockKind::Seconds.key()]
+    }
+
+    fn popup_size(&self) -> Option<(u32, u32)> {
+        Some((POPUP_W, POPUP_H))
+    }
+}

crates/modules/src/lib.rs

@@ -0,0 +1,24 @@
+//! Bar module registry: constructs every enabled module. Adding a module is
+//! a new file under `src/` plus one entry in `all()` — core never changes.
+
+mod audio;
+mod battery;
+mod clock;
+mod weather;
+mod workspaces;
+
+pub use clock::{Clock, ClockError};
+use common::BarModule;
+use toml::Table;
+pub use weather::*;
+
+/// One instance of every enabled module, ready to insert by `id()`.
+pub fn all(module_config: Table) -> Vec<Box<dyn BarModule>> {
+    vec![
+        Box::new(audio::Audio::new()),
+        Box::new(battery::Battery::new(Some(module_config.clone()))),
+        Box::new(clock::Clock::new(Some(module_config.clone()))),
+        Box::new(weather::WeatherModule::default()),
+        Box::new(workspaces::Workspaces::new(Some(module_config))),
+    ]
+}

crates/modules/src/weather.rs

@@ -0,0 +1,104 @@
+use std::error::Error;
+
+use chrono::Timelike;
+use common::{
+    BarModule, ClockKind, ClockPayload, Endpoint, Hourly, ModuleEffect, Service, WeatherKind,
+    WeatherMsg, WeatherPayload, WeatherResponse, Wire,
+};
+use iced::{
+    widget::{container, mouse_area, text},
+    Element, Task,
+};
+
+pub struct WeatherModule {
+    text: String,
+    /// Cached hourly forecast from the last weather update.
+    hourly: Option<Hourly>,
+    /// Current hour, mirrored from the datetime service's clock ticks.
+    hour: Option<u32>,
+}
+
+impl WeatherModule {
+    /// Shows the forecast temperature for the tracked current hour.
+    fn refresh(&mut self) {
+        let (Some(hourly), Some(hour)) = (&self.hourly, self.hour) else {
+            return;
+        };
+        if let Some(i) = hourly.time.iter().position(|t| t.hour() == hour) {
+            if let Some(&temp) = hourly.temperature_2m.get(i) {
+                let value = format!("{}°", temp as i32);
+                if self.text != value {
+                    self.text = value;
+                    tracing::info!(hour, temp, "weather: current hour");
+                }
+            }
+        }
+    }
+}
+
+impl Default for WeatherModule {
+    fn default() -> Self {
+        Self {
+            text: "waiting ".into(),
+            hourly: None,
+            hour: None,
+        }
+    }
+}
+
+impl BarModule for WeatherModule {
+    fn id(&self) -> &'static str {
+        "weather"
+    }
+
+    fn view(&self, _window_id: Option<iced::window::Id>) -> Element<'_, Wire> {
+        let me = Endpoint::module(self.id());
+        container(mouse_area(text(&self.text).size(16)).on_press(Wire::module(
+            me,
+            self.id(),
+            WeatherKind::Poke,
+        )))
+        .into()
+    }
+
+    fn update(&mut self, msg: Wire) -> Task<ModuleEffect> {
+        // Weather state: cache the hourly forecast, then show the current hour.
+        if let Some(env) = msg.downcast::<WeatherPayload>() {
+            match env.kind {
+                WeatherMsg::State => match env.payload.downcast_ref::<WeatherResponse>() {
+                    Some(resp) => {
+                        self.hourly = Some(resp.hourly.clone());
+                        self.refresh();
+                    }
+                    None => tracing::warn!("weather payload was not a WeatherResponse"),
+                },
+            }
+        }
+        // Clock tick from the datetime service: track the current hour.
+        if let Some(payload) = msg.downcast::<ClockPayload>() {
+            let value = match payload {
+                ClockPayload::Mins(v) | ClockPayload::Seconds(v) => v,
+            };
+            self.hour = value.split(':').next().and_then(|h| h.parse().ok());
+            self.refresh();
+        }
+        match msg.downcast::<WeatherKind>() {
+            Some(WeatherKind::Poke) => {
+                tracing::debug!("weather poked");
+                self.text = "poked".into();
+            }
+            None => (),
+        }
+        Task::none()
+    }
+
+    /// Route keys this module subscribes to.
+    fn services(&self) -> Vec<Service> {
+        vec![WeatherMsg::State.key(), ClockKind::Seconds.key()]
+    }
+
+    /// Optional: read `module.weather` from the config table.
+    fn config(&mut self, _config: toml::Table) -> Result<(), Box<dyn Error>> {
+        Ok(())
+    }
+}

crates/modules/src/workspaces.rs

@@ -0,0 +1,144 @@
+//! Workspaces module: renders workspaces 1–10 as cubes, coloured and scaled by
+//! state — focused largest, existing mid, non-existent smallest. State arrives
+//! as `HyprlandEvent`s from the hyprland service.
+//!
+//! Ported from the Quickshell `Workspaces.qml`: constant 10×15 slot per
+//! workspace, corner radius 2.5, and the inactive cubes scaled about their
+//! centre (0.85 existing / 0.75 absent) so the shrink never shifts the row.
+
+use std::collections::BTreeSet;
+
+use common::{BarModule, HyprlandEvent, HyprlandMsg, ModuleEffect, Service, Wire};
+use iced::border;
+use iced::theme::palette;
+use iced::widget::{container, row, space};
+use iced::{window, Element, Length, Task, Theme};
+use serde::Deserialize;
+use toml::Table;
+
+/// How far each state's cube fades from the theme text colour toward the
+/// theme background. Opaque (mixed, not alpha) so cubes stay solid over the
+/// transparent bar instead of washing out.
+const FADE_ACTIVE: f32 = 0.0;
+const FADE_EXISTS: f32 = 0.55;
+const FADE_ABSENT: f32 = 0.8;
+
+/// Look of the workspace row, from `[modules.workspaces]`; every field
+/// defaults to the value Quickshell's `Workspaces.qml` hardcodes, so an
+/// absent table (or absent key) renders identically to before.
+#[derive(Deserialize)]
+#[serde(default)]
+struct WorkspacesConfig {
+    /// Number of slots to render (workspaces `1..=count`).
+    count: i32,
+    /// Horizontal gap between slots in logical px.
+    gap: f32,
+    /// Slot width in logical px — every workspace keeps this slot, so the
+    /// unfocused shrink never moves the row.
+    slot_w: f32,
+    /// Slot height in logical px.
+    slot_h: f32,
+    /// Corner radius.
+    radius: f32,
+    /// Visual scale per state.
+    scale_active: f32,
+    scale_exists: f32,
+    scale_absent: f32,
+}
+
+impl Default for WorkspacesConfig {
+    fn default() -> Self {
+        Self {
+            count: 10,
+            gap: 6.0,
+            slot_w: 10.0,
+            slot_h: 15.0,
+            radius: 2.5,
+            scale_active: 1.0,
+            scale_exists: 0.85,
+            scale_absent: 0.75,
+        }
+    }
+}
+
+fn config_workspaces(table: Option<Table>) -> Option<WorkspacesConfig> {
+    let ws = table?.get("workspaces")?.clone();
+    ws.try_into().ok()
+}
+
+pub struct Workspaces {
+    cfg: WorkspacesConfig,
+    active: Option<i32>,
+    existing: BTreeSet<i32>,
+}
+
+impl Workspaces {
+    pub fn new(config: Option<Table>) -> Self {
+        Self {
+            cfg: config_workspaces(config).unwrap_or_default(),
+            active: None,
+            existing: BTreeSet::new(),
+        }
+    }
+
+    fn cube(&self, id: i32) -> Element<'_, Wire> {
+        let (fade, scale) = if self.active == Some(id) {
+            (FADE_ACTIVE, self.cfg.scale_active)
+        } else if self.existing.contains(&id) {
+            (FADE_EXISTS, self.cfg.scale_exists)
+        } else {
+            (FADE_ABSENT, self.cfg.scale_absent)
+        };
+        let radius = self.cfg.radius;
+        let bar = container(space())
+            .width(Length::Fixed(self.cfg.slot_w * scale))
+            .height(Length::Fixed(self.cfg.slot_h * scale))
+            .style(move |theme: &Theme| {
+                let p = theme.palette();
+                container::Style {
+                    background: Some(palette::mix(p.text, p.background, fade).into()),
+                    border: border::rounded(radius),
+                    ..Default::default()
+                }
+            });
+        container(bar)
+            .center_x(Length::Fixed(self.cfg.slot_w))
+            .center_y(Length::Fixed(self.cfg.slot_h))
+            .into()
+    }
+}
+
+impl BarModule for Workspaces {
+    fn id(&self) -> &'static str {
+        "workspaces"
+    }
+
+    fn view(&self, _window_id: Option<window::Id>) -> Element<'_, Wire> {
+        row((1..=self.cfg.count).map(|id| self.cube(id)))
+            .spacing(self.cfg.gap)
+            .into()
+    }
+
+    fn update(&mut self, msg: Wire) -> Task<ModuleEffect> {
+        if let Some(event) = msg.downcast::<HyprlandEvent>() {
+            match event {
+                HyprlandEvent::WorkspaceChanged { id, .. } => self.active = Some(*id),
+                HyprlandEvent::WorkspaceAdded { id, .. } => {
+                    self.existing.insert(*id);
+                }
+                HyprlandEvent::WorkspaceRemoved { id, .. } => {
+                    self.existing.remove(id);
+                    if self.active == Some(*id) {
+                        self.active = None;
+                    }
+                }
+                HyprlandEvent::ActiveWindow { .. } | HyprlandEvent::Monitor { .. } => {}
+            }
+        }
+        Task::none()
+    }
+
+    fn services(&self) -> Vec<Service> {
+        vec![HyprlandMsg::Events.key()]
+    }
+}

crates/services/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "services"
+version.workspace = true
+edition.workspace = true
+
+[lib]
+name = "services"
+path = "src/lib.rs"
+
+[dependencies]
+common = { path = "../common" }
+zbus = "5"
+iced = { workspace = true }
+tokio = { workspace = true, features = ["net", "io-util"] }
+tracing = { workspace = true }
+chrono = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+reqwest = { version = "0.13.5", features = ["json"] }
+pipewire-native = "0.1.4"
+pipewire-native-spa = "0.1.4"
+hyprland = { git = "https://github.com/hyprland-community/hyprland-rs", branch = "master", default-features = false, features = ["listener", "tokio"] }

crates/services/README.md

@@ -0,0 +1,113 @@
+# services
+
+Background services. A service owns a route key, runs as an iced
+`Subscription`, receives `common::Wire`s on its `Inbox`, and publishes
+payloads back to every module subscribed to its key. Core maps a `Service`
+route key to a subscription through `IntoSubscription`.
+
+Message types are shared, so they live in the `common` crate, under
+`common/src/messages/services/`. That is what lets a service and the modules
+that consume it name the same payload without either depending on the other.
+
+## Getting started: add a service
+
+1. Declare the service's route key and payload in
+   `crates/common/src/messages/services/greeter.rs`:
+
+```rust
+//! Greeter service messages.
+
+use crate::Service;
+
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum GreeterKind {
+    Hello,
+}
+
+impl GreeterKind {
+    /// Route key a module subscribes under to receive this kind's ticks.
+    pub fn key(self) -> Service {
+        Service(match self {
+            Self::Hello => "greeter.hello",
+        })
+    }
+}
+
+#[derive(Clone)]
+pub struct GreeterPayload {
+    pub value: String,
+}
+```
+
+2. Re-export them from `crates/common/src/messages/services/mod.rs`:
+
+```rust
+mod datetime;
+mod greeter;
+mod weather;
+
+pub use datetime::{ClockKind, ClockPayload};
+pub use greeter::{GreeterKind, GreeterPayload};
+pub use weather::*;
+```
+
+3. Create `crates/services/src/greeter.rs`:
+
+```rust
+use std::time::Duration;
+
+use common::{Endpoint, Inbox, Wire, GreeterPayload};
+use iced::{futures::channel::mpsc, Subscription};
+
+/// Route-key namespace owned by this service; keys look like `"greeter.hello"`.
+pub const NAMESPACE: &str = "greeter.";
+
+pub struct GreeterService;
+
+impl GreeterService {
+    pub fn run(inbox: Inbox) -> Subscription<Wire> {
+        Subscription::run_with(inbox, |inbox| {
+            let key = inbox.key();
+            let mut _rx = inbox.take().expect("inbox receiver is taken once");
+
+            iced::stream::channel(0, move |mut sender: mpsc::Sender<Wire>| async move {
+                let mut interval = tokio::time::interval(Duration::from_secs(5));
+                loop {
+                    interval.tick().await;
+                    // Fan-out: publish to every module subscribed to `key`.
+                    let wire = Wire::topic(Endpoint::service(key), key, GreeterPayload {
+                        value: "hello".into(),
+                    });
+                    if sender.send(wire).await.is_err() {
+                        return;
+                    }
+                }
+            })
+        })
+    }
+}
+```
+
+4. Add one arm to the `IntoSubscription` match in `crates/services/src/lib.rs`:
+
+```rust
+pub mod greeter;
+
+impl IntoSubscription for Service {
+    fn into_subscription(self, inbox: Inbox) -> Subscription<Wire> {
+        match self.0 {
+            key if key.starts_with(datetime::NAMESPACE) => datetime::ClockTicker::run(inbox),
+            key if key.starts_with(weather::NAMESPACE) => weather::WeatherService::run(inbox),
+            key if key.starts_with(greeter::NAMESPACE) => greeter::GreeterService::run(inbox),
+            _ => Subscription::none(),
+        }
+    }
+}
+```
+
+Then a module subscribes by returning `GreeterKind::Hello.key()` from its
+`services()` and downcasts `GreeterPayload` in `update()`.
+
+`run_with(inbox, ..)` keys the subscription by the inbox route key, so the
+same subscription returned on every rebuild is not restarted. The receiver is
+taken once inside the closure — don't call `take()` anywhere else.

crates/services/src/battery.rs

@@ -0,0 +1,289 @@
+//! Battery service: follows UPower's display device over D-Bus and
+//! republishes each aspect whenever UPower pushes a change — no polling.
+//!
+//! Machines without a battery (or without UPower) simply never publish;
+//! the service keeps retrying in case UPower shows up later.
+
+use std::time::Duration;
+
+use common::{BatteryEvent, BatteryStatus, Endpoint, Inbox, Wire};
+use iced::futures::{channel::mpsc, SinkExt, StreamExt};
+use iced::Subscription;
+
+/// Route-key namespace owned by this service; keys are `"battery.<kind>"`.
+pub const NAMESPACE: &str = "battery.";
+
+/// How long to wait before retrying when UPower is unreachable.
+const RETRY: Duration = Duration::from_secs(30);
+/// EMA weight for raw UPower estimates; lower = smoother but laggier.
+// ponytail: fixed alpha, make configurable if laggy/jittery on real hardware.
+const ETA_ALPHA: f64 = 0.3;
+/// Minimum change before republishing ETA; matches the minute-resolution display.
+const ETA_DEADBAND_SECS: u64 = 60;
+
+/// UPower device states (`org.freedesktop.UPower.Device.State`).
+const CHARGING: u32 = 1;
+const DISCHARGING: u32 = 2;
+const EMPTY: u32 = 3;
+const FULLY_CHARGED: u32 = 4;
+
+pub struct BatteryService;
+
+impl BatteryService {
+    pub fn run(inbox: Inbox) -> Subscription<Wire> {
+        Subscription::run_with(inbox, |inbox| {
+            let key = inbox.key();
+            // We dont need to rx any msgs from modules
+            let mut _rx = inbox.take().expect("inbox receiver is taken once");
+
+            iced::stream::channel(0, move |mut sender: mpsc::Sender<Wire>| async move {
+                tracing::info!(key, "battery service started");
+                let mut last: Option<(i32, BatteryStatus, i64, i64)> = None;
+                let mut eta_filter = EtaFilter::default();
+                loop {
+                    match serve(&mut sender, key, &mut last, &mut eta_filter).await {
+                        // Subscriber gone: stop the service.
+                        Ok(false) => return,
+                        Ok(true) => tracing::debug!(key, "upower stream ended; reconnecting"),
+                        Err(err) => tracing::debug!(key, %err, "upower unavailable; retrying"),
+                    }
+                    tokio::time::sleep(RETRY).await;
+                }
+            })
+        })
+    }
+}
+
+/// Follows the display device until UPower goes away. Returns whether the
+/// subscriber is still alive (`false` stops the service, `true` reconnects).
+async fn serve(
+    sender: &mut mpsc::Sender<Wire>,
+    key: &'static str,
+    last: &mut Option<(i32, BatteryStatus, i64, i64)>,
+    eta_filter: &mut EtaFilter,
+) -> Result<bool, zbus::Error> {
+    let conn = zbus::Connection::system().await?;
+    let display = UPowerProxy::new(&conn).await?.get_display_device().await?;
+    let device = DeviceProxy::builder(&conn).path(display)?.build().await?;
+
+    if !emit(sender, key, last, eta_filter, read(&device).await?).await {
+        return Ok(false);
+    }
+
+    let mut percentage = device.receive_percentage_changed().await;
+    let mut state = device.receive_state_changed().await;
+    let mut time_to_empty = device.receive_time_to_empty_changed().await;
+    let mut time_to_full = device.receive_time_to_full_changed().await;
+    loop {
+        // `last` is always `Some` here: the initial read published first.
+        let (percent, status, to_full, to_empty) = last.unwrap_or_default();
+        let current = tokio::select! {
+            Some(change) = percentage.next() => (change.get().await?.round() as i32, status, to_full, to_empty),
+            Some(change) = state.next() => (percent, map_state(change.get().await?), to_full, to_empty),
+            Some(change) = time_to_empty.next() => (percent, status, to_full, change.get().await?),
+            Some(change) = time_to_full.next() => (percent, status, change.get().await?, to_empty),
+            else => return Ok(true),
+        };
+        if !emit(sender, key, last, eta_filter, current).await {
+            return Ok(false);
+        }
+    }
+}
+
+/// Sends the aspects that differ from `last`; `false` when the subscriber
+/// is gone and the service should stop.
+async fn emit(
+    sender: &mut mpsc::Sender<Wire>,
+    key: &'static str,
+    last: &mut Option<(i32, BatteryStatus, i64, i64)>,
+    eta_filter: &mut EtaFilter,
+    (percent, status, to_full, to_empty): (i32, BatteryStatus, i64, i64),
+) -> bool {
+    let mut events = Vec::new();
+    if last.map(|(p, _, _, _)| p) != Some(percent) {
+        tracing::debug!(key, percent, "publishing battery percentage");
+        events.push(BatteryEvent::PercentageChanged(percent));
+    }
+    if last.map(|(_, s, _, _)| s) != Some(status) {
+        tracing::debug!(key, ?status, "publishing battery status");
+        events.push(BatteryEvent::StatusChanged(status));
+    }
+    if let Some(smoothed) = eta_filter.update(status, to_full, to_empty) {
+        tracing::debug!(key, ?smoothed, "publishing battery eta");
+        events.push(BatteryEvent::EtaChanged(smoothed));
+    }
+    *last = Some((percent, status, to_full, to_empty));
+    for event in events {
+        let wire = Wire::topic(Endpoint::service(key), key, event);
+        if sender.send(wire).await.is_err() {
+            tracing::warn!(key, "battery send failed; stopping service");
+            return false;
+        }
+    }
+    true
+}
+
+/// Current percentage, status, and raw UPower time estimates of the display device.
+async fn read(device: &DeviceProxy<'_>) -> Result<(i32, BatteryStatus, i64, i64), zbus::Error> {
+    Ok((
+        device.percentage().await?.round() as i32,
+        map_state(device.state().await?),
+        device.time_to_full().await?,
+        device.time_to_empty().await?,
+    ))
+}
+
+/// Low-pass + deadband filter for UPower's jittery time estimates.
+/// `update` returns `Some` only when the module should be notified.
+#[derive(Default)]
+struct EtaFilter {
+    smooth: Option<f64>,
+    status: Option<BatteryStatus>,
+    published: Option<Option<u64>>,
+}
+
+impl EtaFilter {
+    fn update(
+        &mut self,
+        status: BatteryStatus,
+        to_full: i64,
+        to_empty: i64,
+    ) -> Option<Option<u64>> {
+        let raw = eta(status, to_full, to_empty);
+        let Some(raw) = raw else {
+            self.smooth = None;
+            self.status = Some(status);
+            // First run with no estimate: nothing to report (matches unfiltered behavior).
+            let changed = self.published.is_some_and(|p| p.is_some());
+            self.published = Some(None);
+            return changed.then_some(None);
+        };
+        // Estimate source switches with charge state, so past smoothing is stale.
+        let reset = self.status != Some(status) || self.smooth.is_none();
+        self.status = Some(status);
+        let smooth = if reset {
+            raw as f64
+        } else {
+            ETA_ALPHA * raw as f64 + (1.0 - ETA_ALPHA) * self.smooth.unwrap_or(raw as f64)
+        };
+        self.smooth = Some(smooth);
+        let candidate = smooth.round() as u64;
+        match self.published {
+            // First sample: publish immediately.
+            None => {
+                self.published = Some(Some(candidate));
+                Some(Some(candidate))
+            }
+            Some(published) => {
+                let drift = published.map_or(u64::MAX, |p| p.abs_diff(candidate));
+                if reset || drift >= ETA_DEADBAND_SECS {
+                    self.published = Some(Some(candidate));
+                    Some(Some(candidate))
+                } else {
+                    None
+                }
+            }
+        }
+    }
+}
+
+/// Seconds until full while charging, or until empty while discharging.
+/// UPower reports 0 when there is no estimate, and neither state applies
+/// once full, empty, or unknown — all of those surface as `None`.
+fn eta(status: BatteryStatus, to_full: i64, to_empty: i64) -> Option<u64> {
+    let secs = match status {
+        BatteryStatus::Charging => to_full,
+        BatteryStatus::Discharging => to_empty,
+        _ => return None,
+    };
+    (secs > 0).then_some(secs as u64)
+}
+
+/// UPower reports pending/unknown states our protocol has no variant for;
+/// those surface as [`BatteryStatus::Unknown`].
+fn map_state(state: u32) -> BatteryStatus {
+    match state {
+        CHARGING => BatteryStatus::Charging,
+        DISCHARGING => BatteryStatus::Discharging,
+        EMPTY => BatteryStatus::Empty,
+        FULLY_CHARGED => BatteryStatus::Full,
+        _ => BatteryStatus::Unknown,
+    }
+}
+
+#[zbus::proxy(
+    interface = "org.freedesktop.UPower",
+    default_service = "org.freedesktop.UPower",
+    default_path = "/org/freedesktop/UPower"
+)]
+trait UPower {
+    /// Path of the composite display device aggregating all batteries.
+    fn get_display_device(&self) -> zbus::Result<zbus::zvariant::OwnedObjectPath>;
+}
+
+#[zbus::proxy(
+    interface = "org.freedesktop.UPower.Device",
+    default_service = "org.freedesktop.UPower"
+)]
+trait Device {
+    /// Charge percentage (0..=100).
+    #[zbus(property)]
+    fn percentage(&self) -> zbus::Result<f64>;
+
+    /// Device state (1 = charging, 2 = discharging, 3 = empty, 4 = full).
+    #[zbus(property)]
+    fn state(&self) -> zbus::Result<u32>;
+
+    /// Seconds until empty (0 when unknown).
+    #[zbus(property)]
+    fn time_to_empty(&self) -> zbus::Result<i64>;
+
+    /// Seconds until full (0 when unknown).
+    #[zbus(property)]
+    fn time_to_full(&self) -> zbus::Result<i64>;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const DIS: BatteryStatus = BatteryStatus::Discharging;
+
+    #[test]
+    fn jitter_within_deadband_is_suppressed() {
+        let mut f = EtaFilter::default();
+        assert_eq!(f.update(DIS, 0, 3600), Some(Some(3600)));
+        assert_eq!(f.update(DIS, 0, 3610), None);
+        assert_eq!(f.update(DIS, 0, 3590), None);
+    }
+
+    #[test]
+    fn large_step_publishes_smoothed_value() {
+        let mut f = EtaFilter::default();
+        assert_eq!(f.update(DIS, 0, 3600), Some(Some(3600)));
+        // EMA: 0.3*1800 + 0.7*3600 = 3060, drift 540 >= 60.
+        assert_eq!(f.update(DIS, 0, 1800), Some(Some(3060)));
+    }
+
+    #[test]
+    fn status_flip_resets_and_publishes() {
+        let mut f = EtaFilter::default();
+        assert_eq!(f.update(DIS, 0, 3600), Some(Some(3600)));
+        assert_eq!(f.update(BatteryStatus::Charging, 1200, 0), Some(Some(1200)));
+    }
+
+    #[test]
+    fn loss_and_return_of_estimate_publishes() {
+        let mut f = EtaFilter::default();
+        assert_eq!(f.update(DIS, 0, 3600), Some(Some(3600)));
+        assert_eq!(f.update(DIS, 0, 0), Some(None));
+        assert_eq!(f.update(DIS, 0, 0), None);
+        assert_eq!(f.update(DIS, 0, 3500), Some(Some(3500)));
+    }
+
+    #[test]
+    fn first_run_without_estimate_stays_silent() {
+        let mut f = EtaFilter::default();
+        assert_eq!(f.update(BatteryStatus::Full, 0, 0), None);
+    }
+}

crates/services/src/compositors/hyprland.rs

@@ -0,0 +1,205 @@
+//! Hyprland compositor service: listens on the compositor's event socket and
+//! republishes focus changes (`HyprlandEvent`) to modules subscribed to
+//! `hyprland.events`.
+//!
+//! Seeds the workspace list and current focus on startup so subscribers have
+//! state before the first event — the event socket only reports changes.
+//!
+//! The startup snapshot is queried over Hyprland's command socket directly:
+//! the `hyprland` crate's `data` types cannot deserialize 0.56 responses
+//! (`Workspace.id` was dropped), though its event stream still works.
+
+use std::path::PathBuf;
+
+use common::{Endpoint, HyprlandEvent, Inbox, Wire};
+use hyprland::event_listener::{Event, EventStream};
+use iced::futures::{channel::mpsc, SinkExt, StreamExt};
+use iced::Subscription;
+use serde::Deserialize;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::UnixStream;
+
+/// Route-key namespace owned by this service; the key is `"hyprland.events"`.
+pub const NAMESPACE: &str = "hyprland.";
+
+/// A workspace as far as the bar cares — only the name, which for numbered
+/// workspaces is also the id.
+#[derive(Deserialize)]
+struct WorkspaceState {
+    name: String,
+}
+
+#[derive(Deserialize)]
+struct ClientState {
+    class: String,
+    title: String,
+}
+
+#[derive(Deserialize)]
+struct MonitorState {
+    name: String,
+    focused: bool,
+}
+
+pub struct HyprlandService;
+
+impl HyprlandService {
+    pub fn run(inbox: Inbox) -> Subscription<Wire> {
+        Subscription::run_with(inbox, |inbox| {
+            let key = inbox.key();
+            let mut _rx = inbox.take().expect("inbox receiver is taken once");
+            iced::stream::channel(0, move |mut sender: mpsc::Sender<Wire>| async move {
+                tracing::info!(key, "hyprland service started");
+
+                if !seed(&mut sender, key).await {
+                    return;
+                }
+
+                let mut stream = EventStream::new();
+                while let Some(event) = stream.next().await {
+                    let event = match event {
+                        Ok(event) => event,
+                        Err(e) => {
+                            tracing::warn!(error = %e, "hyprland event stream error");
+                            continue;
+                        }
+                    };
+                    tracing::debug!(?event, "hyprland raw event");
+                    for event in translate(event) {
+                        if !publish(&mut sender, key, event).await {
+                            return;
+                        }
+                    }
+                }
+                tracing::warn!(key, "hyprland event stream ended");
+            })
+        })
+    }
+}
+
+/// Publishes the current compositor state before live events start; `false`
+/// if the subscriber channel is gone.
+async fn seed(sender: &mut mpsc::Sender<Wire>, key: &'static str) -> bool {
+    if let Some(list) = query::<Vec<WorkspaceState>>("workspaces").await {
+        for ws in list {
+            let event = HyprlandEvent::WorkspaceAdded {
+                id: workspace_id(&ws.name, -1),
+                name: ws.name,
+            };
+            if !publish(sender, key, event).await {
+                return false;
+            }
+        }
+    }
+    if let Some(ws) = query::<WorkspaceState>("activeworkspace").await {
+        let event = HyprlandEvent::WorkspaceChanged {
+            id: workspace_id(&ws.name, -1),
+            name: ws.name,
+        };
+        if !publish(sender, key, event).await {
+            return false;
+        }
+    }
+    if let Some(m) = query::<Vec<MonitorState>>("monitors")
+        .await
+        .and_then(|list| list.into_iter().find(|m| m.focused))
+    {
+        if !publish(sender, key, HyprlandEvent::Monitor { name: m.name }).await {
+            return false;
+        }
+    }
+    if let Some(c) = query::<ClientState>("activewindow").await {
+        let event = HyprlandEvent::ActiveWindow {
+            class: c.class,
+            title: c.title,
+        };
+        if !publish(sender, key, event).await {
+            return false;
+        }
+    }
+    true
+}
+
+/// Runs `j/<cmd>` against Hyprland's command socket and parses the reply.
+/// `None` if Hyprland isn't running, the query fails, or the shape is unknown.
+async fn query<T: for<'de> Deserialize<'de>>(cmd: &str) -> Option<T> {
+    let runtime = std::env::var_os("XDG_RUNTIME_DIR")?;
+    let signature = std::env::var_os("HYPRLAND_INSTANCE_SIGNATURE")?;
+    let path = PathBuf::from(runtime)
+        .join("hypr")
+        .join(signature)
+        .join(".socket.sock");
+
+    let mut stream = UnixStream::connect(path).await.ok()?;
+    stream.write_all(format!("j/{cmd}").as_bytes()).await.ok()?;
+    let mut reply = String::new();
+    stream.read_to_string(&mut reply).await.ok()?;
+    serde_json::from_str(&reply).ok()
+}
+
+/// Workspace id for the bar: the numeric name when it is one (numbered
+/// workspaces), else `fallback` (the event's own id, `-1` when unknown).
+fn workspace_id(name: &str, fallback: i32) -> i32 {
+    name.parse().unwrap_or(fallback)
+}
+
+/// Publishes one event to subscribers; `false` if the channel is gone.
+async fn publish(sender: &mut mpsc::Sender<Wire>, key: &'static str, event: HyprlandEvent) -> bool {
+    tracing::debug!(?event, "hyprland event");
+    let wire = Wire::topic(Endpoint::service(key), key, event);
+    if sender.send(wire).await.is_err() {
+        tracing::warn!(key, "hyprland send failed; stopping service");
+        return false;
+    }
+    true
+}
+
+/// Maps one crate event onto the protocol payload(s); empty for events the
+/// bar does not publish. `focusedmon` yields two: the monitor change *and* the
+/// workspace that monitor just focused.
+fn translate(event: Event) -> Vec<HyprlandEvent> {
+    match event {
+        Event::WorkspaceChanged(w) => {
+            let name = w.name.to_string();
+            vec![HyprlandEvent::WorkspaceChanged {
+                id: workspace_id(&name, w.id),
+                name,
+            }]
+        }
+        Event::WorkspaceAdded(w) => {
+            let name = w.name.to_string();
+            vec![HyprlandEvent::WorkspaceAdded {
+                id: workspace_id(&name, w.id),
+                name,
+            }]
+        }
+        Event::WorkspaceDeleted(w) => {
+            let name = w.name.to_string();
+            vec![HyprlandEvent::WorkspaceRemoved {
+                id: workspace_id(&name, w.id),
+                name,
+            }]
+        }
+        Event::ActiveWindowChanged(w) => vec![HyprlandEvent::ActiveWindow {
+            class: w.as_ref().map(|w| w.class.clone()).unwrap_or_default(),
+            title: w.map(|w| w.title).unwrap_or_default(),
+        }],
+        Event::ActiveMonitorChanged(m) => {
+            let mut events = vec![HyprlandEvent::Monitor {
+                name: m.monitor_name,
+            }];
+            // Focusing a monitor also focuses its workspace; switching to a
+            // workspace on another monitor fires only this event, so without
+            // it the bar's active workspace never updates.
+            if let Some(ws) = m.workspace_name {
+                let name = ws.to_string();
+                events.push(HyprlandEvent::WorkspaceChanged {
+                    id: workspace_id(&name, -1),
+                    name,
+                });
+            }
+            events
+        }
+        _ => Vec::new(),
+    }
+}

crates/services/src/compositors/mod.rs

@@ -0,0 +1 @@
+pub mod hyprland;

crates/services/src/datetime.rs

@@ -0,0 +1,72 @@
+//! Clock service: publishes a `Wire` on every change of the displayed
+//! value, and accepts `ClockKind` wires from modules that want it to switch
+//! which kind it publishes.
+//!
+//! The ticker knows nothing about the app's `Message` type; it produces
+//! protocol wires from `common` that core routes to subscribers.
+
+
+use chrono::{DateTime, Local, Timelike};
+use iced::futures::{channel::mpsc, SinkExt};
+use iced::Subscription;
+
+use common::{ClockPayload, Endpoint, Inbox, Wire};
+
+/// Route-key namespace owned by this service; keys are `"clock.<kind>"`.
+pub const NAMESPACE: &str = "clock.";
+
+/// Drives the clock, publishing only the kind modules last asked for.
+#[derive(Default)]
+pub struct ClockTicker {
+    last: DateTime<Local>,
+    // want: ClockKind,
+}
+
+impl ClockTicker {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Subscription that reads inbound wires from `inbox` and publishes
+    /// changes to every module subscribed to this service's route key.
+    pub fn run(inbox: Inbox) -> Subscription<Wire> {
+        Subscription::run_with(inbox, |inbox| {
+            let key = inbox.key();
+            // We dont need to rx any msgs from modules
+            let mut _rx = inbox.take().expect("inbox receiver is taken once");
+
+            iced::stream::channel(0, move |mut sender: mpsc::Sender<Wire>| async move {
+                let mut clock = ClockTicker::new();
+                let mut interval = tokio::time::interval(std::time::Duration::from_secs(1));
+                tracing::info!(key, "clock service started");
+                loop {
+                    tokio::select! {
+                        _ = interval.tick() => {
+                            if let Some(payload) = clock.tick() {
+                                tracing::debug!(key, ?payload, "publishing clock");
+                                let wire = Wire::topic(Endpoint::service(key), key, payload);
+                                if sender.send(wire).await.is_err() {
+                                    tracing::warn!(key, "clock send failed; stopping service");
+                                    return;
+                                }
+                            }
+                        }
+                    }
+                }
+            })
+        })
+    }
+
+    /// Latest value for the wanted kind, or `None` if unchanged.
+    pub fn tick(&mut self) -> Option<ClockPayload> {
+        let value = chrono::Local::now();
+        let meow = self.last;
+        if meow.minute() != value.minute() {
+            return Some(ClockPayload::Mins(value.format("%H:%M:%S").to_string()));
+        }
+        if meow.second() != value.second() {
+            return Some(ClockPayload::Seconds(value.format("%H:%M:%S").to_string()));
+        }
+        None
+    }
+}

crates/services/src/lib.rs

@@ -0,0 +1,41 @@
+//! Service registry: turns a route key into the subscription that backs it.
+//! Adding a service is a new file under `src/` plus one arm in the impl below
+//! — core never changes.
+
+use iced::Subscription;
+
+use common::{Inbox, Service, Wire};
+
+pub mod battery;
+pub mod compositors;
+pub mod datetime;
+pub mod pipewire;
+pub mod weather;
+
+/// Conversion from a route key + its inbox to the subscription backing it.
+///
+/// An extension trait (not `impl From<Service> for Subscription<...>`) because
+/// both `Service` and `Subscription` are foreign to this crate — the orphan
+/// rule blocks a foreign trait (`From`) on a foreign type (`Subscription`).
+pub trait IntoSubscription {
+    fn into_subscription(self, inbox: Inbox) -> Subscription<Wire>;
+}
+
+impl IntoSubscription for Service {
+    fn into_subscription(self, inbox: Inbox) -> Subscription<Wire> {
+        let key = self.0;
+        match key {
+            k if k.starts_with(battery::NAMESPACE) => battery::BatteryService::run(inbox),
+            k if k.starts_with(datetime::NAMESPACE) => datetime::ClockTicker::run(inbox),
+            k if k.starts_with(compositors::hyprland::NAMESPACE) => {
+                compositors::hyprland::HyprlandService::run(inbox)
+            }
+            k if k.starts_with(weather::NAMESPACE) => weather::WeatherService::run(inbox),
+            k if k.starts_with(pipewire::NAMESPACE) => pipewire::PipewireService::run(inbox),
+            _ => {
+                tracing::warn!(service = key, "no service impl for route key");
+                Subscription::none()
+            }
+        }
+    }
+}

crates/services/src/pipewire.rs

@@ -0,0 +1,321 @@
+//! PipeWire service: follows the default sink and source — WirePlumber names
+//! them in its `default` metadata — and republishes their volume/mute
+//! whenever PipeWire reports a change.
+//!
+//! PipeWire drives its own main loop, so the connection lives on a dedicated
+//! thread; that thread hands state to the async side over a channel.
+
+use std::collections::HashMap;
+use std::sync::{Arc, Mutex};
+
+use common::{AudioNode, Endpoint, Inbox, PipewireState, Wire};
+use iced::futures::{channel::mpsc, SinkExt};
+use iced::Subscription;
+use pipewire_native as pw;
+use pipewire_native::context::Context;
+use pipewire_native::core::Core;
+use pipewire_native::main_loop::MainLoop;
+use pipewire_native::properties::Properties;
+use pipewire_native::proxy::metadata::{Metadata, MetadataEvents};
+use pipewire_native::proxy::node::{Node, NodeEvents};
+use pipewire_native::proxy::registry::{Registry, RegistryEvents};
+use pipewire_native::proxy::{HasProxy, ProxyEvents};
+use pipewire_native::some_closure;
+use pipewire_native::types;
+use pipewire_native_spa as spa;
+use tokio::sync::mpsc as tokio_mpsc;
+
+/// Route-key namespace owned by this service; keys are `"pipewire.<kind>"`.
+pub const NAMESPACE: &str = "pipewire.";
+
+/// Node classes the service follows.
+const SINK: &str = "Audio/Sink";
+const SOURCE: &str = "Audio/Source";
+
+/// WirePlumber's metadata object holding the default nodes.
+const DEFAULTS: &str = "default";
+const DEFAULT_SINK: &str = "default.audio.sink";
+const DEFAULT_SOURCE: &str = "default.audio.source";
+
+pub struct PipewireService;
+
+impl PipewireService {
+    pub fn run(inbox: Inbox) -> Subscription<Wire> {
+        Subscription::run_with(inbox, |inbox| {
+            let key = inbox.key();
+            // We dont need to rx any msgs from modules
+            let mut _rx = inbox.take().expect("inbox receiver is taken once");
+
+            iced::stream::channel(0, move |mut sender: mpsc::Sender<Wire>| async move {
+                // The PipeWire thread owns the connection and drops it once
+                // this channel goes away, which stops its loop.
+                let (tx, mut rx) = tokio_mpsc::unbounded_channel();
+                std::thread::spawn(move || connect(tx));
+                while let Some(state) = rx.recv().await {
+                    tracing::debug!(?state, "pipewire state changed");
+                    let wire = Wire::topic(Endpoint::service(key), key, state);
+                    if sender.send(wire).await.is_err() {
+                        tracing::warn!(key, "pipewire send failed; stopping service");
+                        return;
+                    }
+                }
+            })
+        })
+    }
+}
+
+/// Connects, follows the default nodes, and runs PipeWire's loop until the
+/// subscriber (or PipeWire itself) goes away.
+fn connect(tx: tokio_mpsc::UnboundedSender<PipewireState>) {
+    pw::init();
+    let conn = match Connection::open() {
+        Ok(conn) => conn,
+        Err(err) => {
+            tracing::warn!(%err, "pipewire unavailable; audio state stays unknown");
+            return;
+        }
+    };
+
+    let track = Arc::new(Mutex::new(Track::new(conn, tx)));
+    watch(&track);
+    let main_loop = track.lock().unwrap().conn.main_loop.clone();
+
+    tracing::info!("pipewire connected");
+    main_loop.run();
+    tracing::info!("pipewire disconnected");
+}
+
+/// The connection chain: PipeWire tears the session down if any link of it
+/// goes away, so all of it lives for as long as the loop runs.
+struct Connection {
+    main_loop: MainLoop,
+    _context: Context,
+    _core: Core,
+    registry: Registry,
+}
+
+impl Connection {
+    fn open() -> std::io::Result<Self> {
+        let main_loop = MainLoop::new(&Properties::new())
+            .ok_or_else(|| std::io::Error::other("pipewire main loop unavailable"))?;
+        let context = Context::new(&main_loop, Properties::new())?;
+        let core = context.connect(None)?;
+        let registry = core.registry()?;
+        Ok(Self {
+            main_loop,
+            _context: context,
+            _core: core,
+            registry,
+        })
+    }
+}
+
+/// Subscribes to every sink/source node and to the `default` metadata, so
+/// PipeWire pushes volume/mute changes instead of us polling for them.
+fn watch(track: &Arc<Mutex<Track>>) {
+    let registry = track.lock().unwrap().conn.registry.clone();
+    registry.add_listener(RegistryEvents {
+        global: some_closure!([registry ^(track)] id, _perms, type_, version, props, {
+            match type_ {
+                types::interface::NODE => {
+                    let class = props.get("media.class").unwrap_or_default();
+                    if class != SINK && class != SOURCE {
+                        return;
+                    }
+                    if let Some(name) = props.get("node.name") {
+                        bind_node(track, &registry, id, type_, version, name.to_string());
+                    }
+                }
+                types::interface::METADATA if props.get("metadata.name") == Some(DEFAULTS) => {
+                    bind_defaults(track, &registry, id, type_, version);
+                }
+                _ => {}
+            }
+        }),
+        global_remove: some_closure!([^(track)] id, {
+            let mut track = track.lock().unwrap();
+            if let Some(name) = track.ids.remove(&id) {
+                track.nodes.remove(&name);
+                track.publish();
+            }
+        }),
+    });
+}
+
+/// Binds a sink/source node and follows its `Props` param (volume + mute).
+fn bind_node(
+    track: &Arc<Mutex<Track>>,
+    registry: &Registry,
+    id: pw::Id,
+    type_: &str,
+    version: u32,
+    name: String,
+) {
+    let Ok(object) = registry.bind(id, type_, version) else {
+        return;
+    };
+    let Some(proxy) = object.downcast_proxy::<Node>() else {
+        return;
+    };
+    let Some(node) = proxy.object() else {
+        return;
+    };
+
+    node.add_listener(NodeEvents {
+        param: some_closure!([^(track, name)] _seq, id, _index, _next, pod, {
+            if id != spa::param::ParamType::Props {
+                return;
+            }
+            let mut track = track.lock().unwrap();
+            merge(track.nodes.entry(name.clone()).or_default(), pod);
+            track.publish();
+        }),
+        ..Default::default()
+    });
+
+    // A local proxy is only usable once the server has bound it, and asking
+    // for params is a method call.
+    proxy.add_listener(ProxyEvents {
+        bound_props: some_closure!([^(node)] _id, _props, {
+            let _ = node.subscribe_params(&[spa::param::ParamType::Props]);
+            let _ = node.enum_params(0, Some(spa::param::ParamType::Props), 0, u32::MAX, None);
+        }),
+        ..Default::default()
+    });
+
+    tracing::debug!(name, "following pipewire node");
+    let mut track = track.lock().unwrap();
+    track.ids.insert(id, name);
+    track.keep.push(object);
+}
+
+/// Binds WirePlumber's `default` metadata and follows which nodes are the
+/// current sink and source.
+fn bind_defaults(
+    track: &Arc<Mutex<Track>>,
+    registry: &Registry,
+    id: pw::Id,
+    type_: &str,
+    version: u32,
+) {
+    let Ok(object) = registry.bind(id, type_, version) else {
+        return;
+    };
+    let Some(proxy) = object.downcast_proxy::<Metadata>() else {
+        return;
+    };
+    let Some(metadata) = proxy.object() else {
+        return;
+    };
+
+    metadata.add_listener(MetadataEvents {
+        property: some_closure!([^(track)] _subject, key, _type, value, {
+            let (Some(key), Some(value)) = (key, value) else {
+                return;
+            };
+            let Some(name) = default_node(value) else {
+                return;
+            };
+            let mut track = track.lock().unwrap();
+            match key {
+                DEFAULT_SINK => track.sink = Some(name),
+                DEFAULT_SOURCE => track.source = Some(name),
+                _ => return,
+            }
+            track.publish();
+        }),
+    });
+
+    tracing::debug!("following pipewire default metadata");
+    track.lock().unwrap().keep.push(object);
+}
+
+/// Merges the volume/mute carried by a `SPA_PARAM_Props` pod into `state`;
+/// anything the pod leaves out keeps its previous value.
+fn merge(state: &mut AudioNode, pod: &spa::pod::RawPodOwned) {
+    let mut parser = spa::pod::parser::Parser::new(pod.data());
+    let _ = parser.pop_object::<spa::param::props::Prop, spa::param::ParamType, _>(|props, _id| {
+        for (key, _flags, value) in props {
+            match key {
+                spa::param::props::Prop::Volume => {
+                    if let Ok(volume) = value.decode::<f32>() {
+                        state.volume = volume;
+                    }
+                }
+                spa::param::props::Prop::Mute => {
+                    if let Ok(muted) = value.decode::<bool>() {
+                        state.muted = muted;
+                    }
+                }
+                _ => {}
+            }
+        }
+        Ok(())
+    });
+}
+
+/// WirePlumber stores a default as `{"name":"<node.name>"}`.
+fn default_node(value: &str) -> Option<String> {
+    #[derive(serde::Deserialize)]
+    struct Default {
+        name: String,
+    }
+    serde_json::from_str::<Default>(value).ok().map(|d| d.name)
+}
+
+/// What the PipeWire callbacks share: the connection, the audio state they
+/// observe, and the channel home.
+struct Track {
+    conn: Connection,
+    /// Volume/mute of every sink and source, keyed by `node.name`.
+    nodes: HashMap<String, AudioNode>,
+    /// Registry id -> `node.name`, so a removed node can be forgotten.
+    ids: HashMap<pw::Id, String>,
+    /// `node.name` of the default sink/source, per the metadata.
+    sink: Option<String>,
+    source: Option<String>,
+    /// Bound proxies, kept alive so their listeners stay registered.
+    keep: Vec<Box<dyn HasProxy>>,
+    tx: tokio_mpsc::UnboundedSender<PipewireState>,
+    /// Last state published, so redundant updates are dropped.
+    sent: Option<PipewireState>,
+}
+
+impl Track {
+    fn new(conn: Connection, tx: tokio_mpsc::UnboundedSender<PipewireState>) -> Self {
+        Self {
+            conn,
+            nodes: HashMap::new(),
+            ids: HashMap::new(),
+            sink: None,
+            source: None,
+            keep: Vec::new(),
+            tx,
+            sent: None,
+        }
+    }
+
+    /// Publishes the default sink/source, if the state actually changed.
+    fn publish(&mut self) {
+        let state = PipewireState {
+            sink: self.node(&self.sink),
+            source: self.node(&self.source),
+        };
+        if self.sent == Some(state) {
+            return;
+        }
+        self.sent = Some(state);
+        if self.tx.send(state).is_err() {
+            tracing::info!("pipewire subscriber gone; disconnecting");
+            self.conn.main_loop.quit();
+        }
+    }
+
+    /// State of the named node; zeroes while the default is unknown.
+    fn node(&self, name: &Option<String>) -> AudioNode {
+        name.as_ref()
+            .and_then(|name| self.nodes.get(name))
+            .copied()
+            .unwrap_or_default()
+    }
+}

crates/services/src/weather.rs

@@ -0,0 +1,74 @@
+use std::{sync::Arc, time::Duration};
+
+use common::{Endpoint, Inbox, WeatherMsg, WeatherPayload, WeatherResponse, Wire};
+use iced::{
+    futures::{channel::mpsc, SinkExt},
+    Subscription,
+};
+use tokio::time::interval;
+
+pub const NAMESPACE: &str = "weather.";
+
+const FORECAST_URL: &str = "https://api.open-meteo.com/v1/forecast\
+?latitude=51.3714&longitude=-0.2302\
+&hourly=temperature_2m,rain,showers,precipitation,relative_humidity_2m";
+
+pub struct WeatherService {
+    client: reqwest::Client,
+}
+
+impl WeatherService {
+    fn new() -> Self {
+        Self {
+            client: reqwest::Client::default(),
+        }
+    }
+    pub fn run(inbox: Inbox) -> Subscription<Wire> {
+        Subscription::run_with(inbox, |inbox| {
+            let key = inbox.key();
+            let mut _rx = inbox.take().expect("cant take");
+
+            iced::stream::channel(0, move |mut sender: mpsc::Sender<Wire>| async move {
+                let weather = WeatherService::new();
+                let mut interval = interval(Duration::from_mins(30));
+                tracing::info!(key = key, "weather service started");
+                loop {
+                    tokio::select! {
+                        _ = interval.tick() => {
+                            if let Some(resp) = weather.get_weather().await {
+                                let env = WeatherPayload {
+                                    kind: WeatherMsg::State,
+                                    payload: Arc::new(resp),
+                                };
+                                let wire = Wire::topic(Endpoint::service(key), key, env);
+                                if sender.send(wire).await.is_err() {
+                                    tracing::warn!(key, "weather send failed; stopping service");
+                                    return;
+                                }
+                            }
+                        }
+                    }
+                }
+            })
+        })
+    }
+    async fn get_weather(&self) -> Option<WeatherResponse> {
+        tracing::debug!(url = FORECAST_URL, "fetching weather");
+        match self.client.get(FORECAST_URL).send().await {
+            Ok(resp) => match resp.json::<WeatherResponse>().await {
+                Ok(parsed) => {
+                    tracing::debug!("weather fetched");
+                    Some(parsed)
+                }
+                Err(e) => {
+                    tracing::warn!(error = %e, "weather response decode failed");
+                    None
+                }
+            },
+            Err(e) => {
+                tracing::warn!(error = %e, "weather request failed");
+                None
+            }
+        }
+    }
+}

example_base16.yaml

@@ -0,0 +1,18 @@
+scheme: "Gruvbox dark, medium"
+author: "https://github.com/morhetz/gruvbox"
+base00: "282828" # bg
+base01: "3c3836" # bg1
+base02: "504945" # bg2
+base03: "665c54" # bg3
+base04: "bdae93" # fg4
+base05: "d5c4a1" # fg
+base06: "ebdbb2" # fg2
+base07: "fbf1c7" # fg0
+base08: "fb4934" # red
+base09: "fe8019" # orange
+base0A: "fabd2f" # yellow
+base0B: "b8bb26" # green
+base0C: "8ec07c" # aqua
+base0D: "83a598" # blue
+base0E: "d3869b" # purple
+base0F: "d65d0e" # brown

flake.nix

@@ -22,7 +22,7 @@
       flake-utils,
       ...
     }@inputs:
-    flake-utils.lib.eachDefaultSystem (
+    (flake-utils.lib.eachDefaultSystem (
       system:
       let
         pkgs = import inputs.nixpkgs {
@@ -59,6 +59,8 @@
         # Common arguments can be set here to avoid repeating them later
         # Note: changes here will rebuild all dependency crates
         commonArgs = {
+          pname = "barbar";
+          version = (builtins.fromTOML (builtins.readFile ./Cargo.toml)).workspace.package.version;
           # Exclude build outputs regardless of git state (this repo is not
           # git-initialized, so cleanCargoSource would otherwise copy target/).
           src = pkgs.lib.cleanSourceWith {
@@ -72,8 +74,17 @@
           };
           strictDeps = true;
 
-          nativeBuildInputs = [
+          nativeBuildInputs =
+            [
               pkgs.pkg-config
+              # libspa-0.2.pc: pipewire-native bakes the SPA plugin directory
+              # from it, and loads libspa-support from there at runtime.
+              pkgs.pipewire.dev
+            ]
+            # mold for the final link; the flag itself comes from the
+            # repo-wide .cargo/config.toml so dev and nix builds share one.
+            ++ pkgs.lib.optionals pkgs.stdenv.hostPlatform.isLinux [
+              pkgs.mold
             ];
 
           buildInputs =
@@ -87,23 +98,42 @@
         my-crate = craneLib.buildPackage (
           commonArgs
           // {
-            cargoArtifacts = craneLib.buildDepsOnly commonArgs;
+            cargoArtifacts = craneLib.buildDepsOnly (commonArgs // {
+              src = craneLib.cleanCargoSource ./.;
+            });
 
             # Additional environment variables or build phases/hooks can be set
             # here *without* rebuilding all dependency crates
             # MY_CUSTOM_VAR = "some value";
           }
         );
+
+        # winit dlopens libwayland and wgpu the vulkan loader at runtime, which
+        # rpath alone does not cover; wrap the binary with LD_LIBRARY_PATH so
+        # the package also runs outside the devShell (e.g. from systemd).
+        barbar = pkgs.symlinkJoin {
+          name = "barbar-${my-crate.version}";
+          paths = [ my-crate ];
+          nativeBuildInputs = [ pkgs.makeWrapper ];
+          postBuild = ''
+            wrapProgram $out/bin/core \
+              --prefix LD_LIBRARY_PATH : ${pkgs.lib.makeLibraryPath guiLibs} \
+              --set SPA_PLUGIN_DIR ${pkgs.pipewire}/lib/spa-0.2 \
+              --set PIPEWIRE_CONFIG_DIR ${pkgs.pipewire}/share/pipewire
+          '';
+          meta.mainProgram = "core";
+        };
       in
       {
         checks = {
           inherit my-crate;
         };
 
-        packages.default = my-crate;
+        packages.default = barbar;
 
         apps.default = flake-utils.lib.mkApp {
-          drv = my-crate;
+          drv = barbar;
+          exePath = "/bin/core";
         };
 
         devShells.default = craneLib.devShell {
@@ -112,13 +142,24 @@
 
           # Put the GUI shared libraries on the runtime library path so winit
           # can dlopen libwayland and wgpu can find the vulkan loader.
+          # No RUSTFLAGS here: an env RUSTFLAGS would override (not merge
+          # with) .cargo/config.toml's rustflags, giving devShell and
+          # non-devShell builds different fingerprints and force-rebuilding
+          # every dependency on each switch.
           shellHook = ''
             export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${pkgs.lib.makeLibraryPath guiLibs}"
+            # pipewire-native dlopens SPA plugins and reads client.conf.
+            export SPA_PLUGIN_DIR="${pkgs.pipewire}/lib/spa-0.2"
+            export PIPEWIRE_CONFIG_DIR="${pkgs.pipewire}/share/pipewire"
           '';
 
           # Extra inputs can be added here; cargo and rustc are provided by default.
-          packages = guiLibs;
+          packages = guiLibs ++ [ pkgs.pipewire.dev ] ++ pkgs.lib.optionals pkgs.stdenv.hostPlatform.isLinux [ pkgs.mold ];
         };
       }
-    );
+    ))
+    // {
+      # System-independent, so it lives outside eachDefaultSystem.
+      homeManagerModules.default = import ./nix/home-manager.nix self;
+    };
 }

nix/home-manager.nix

@@ -0,0 +1,86 @@
+# Home Manager module for barbar.
+#
+#   imports = [ inputs.barbar.homeManagerModules.default ];
+#
+# Generates barbar.toml from `programs.barbar.settings` and runs the bar as a
+# systemd user service bound to the graphical session.
+self:
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.programs.barbar;
+  toml = pkgs.formats.toml { };
+  configFile = toml.generate "barbar.toml" cfg.settings;
+in
+{
+  options.programs.barbar = {
+    enable = lib.mkEnableOption "barbar, a Wayland layer-shell status bar";
+
+    package = lib.mkOption {
+      type = lib.types.package;
+      default = self.packages.${pkgs.stdenv.hostPlatform.system}.default;
+      defaultText = lib.literalExpression "barbar.packages.\${system}.default";
+      description = "The barbar package to run.";
+    };
+
+    settings = lib.mkOption {
+      type = toml.type;
+      default.order = {
+        left = [ ];
+        middle = [ ];
+        right = [ ];
+      };
+      defaultText = lib.literalExpression ''{ order = { left = [ ]; middle = [ ]; right = [ ]; }; }'';
+      description = ''
+        Contents of barbar.toml, written verbatim. Only `order` is required by
+        barbar; `[display]`, `[modules.*]` and `[services.*]` are optional.
+        See test.toml in the barbar repo for the full schema.
+      '';
+      example = lib.literalExpression ''
+        {
+          display = {
+            monitor = "DP-2";
+            height = 24;
+          };
+          order = {
+            left = [ "workspaces" "weather" ];
+            middle = [ ];
+            right = [ "clock" ];
+          };
+          modules.clock.show_seconds = false;
+        }
+      '';
+    };
+
+    systemd.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = true;
+      description = "Run barbar as a systemd user service.";
+    };
+
+    systemd.target = lib.mkOption {
+      type = lib.types.str;
+      default = "graphical-session.target";
+      description = "Systemd target the bar is bound to.";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.user.services.barbar = lib.mkIf cfg.systemd.enable {
+      Unit = {
+        Description = "barbar status bar";
+        After = [ cfg.systemd.target ];
+        PartOf = [ cfg.systemd.target ];
+      };
+      Service = {
+        ExecStart = "${lib.getExe' cfg.package "core"} --config ${configFile}";
+        Restart = "on-failure";
+      };
+      Install.WantedBy = [ cfg.systemd.target ];
+    };
+  };
+}

src/bounds.rs

@@ -1,45 +0,0 @@
-//! Widget-tree operation that captures the laid-out bounds of a clickable
-//! bar module so a popup can be anchored to it.
-
-use iced::advanced::widget as advanced_widget;
-use iced::widget::Id;
-use iced::{Rectangle, Task};
-
-/// Captures the laid-out bounds of the module with the given id, reported via
-/// `BoundsFound`.
-pub fn capture_bounds(label: String) -> Task<crate::Message> {
-    let target = Id::from(label.clone());
-
-    struct FindBounds {
-        target: Id,
-        found: Option<Rectangle>,
-    }
-
-    impl advanced_widget::Operation<Rectangle> for FindBounds {
-        fn traverse(
-            &mut self,
-            operate: &mut dyn FnMut(&mut dyn advanced_widget::Operation<Rectangle>),
-        ) {
-            operate(self);
-        }
-
-        fn container(&mut self, id: Option<&Id>, bounds: Rectangle) {
-            if self.found.is_none() && id == Some(&self.target) {
-                self.found = Some(bounds);
-            }
-        }
-
-        fn finish(&self) -> advanced_widget::operation::Outcome<Rectangle> {
-            match self.found {
-                Some(bounds) => advanced_widget::operation::Outcome::Some(bounds),
-                None => advanced_widget::operation::Outcome::None,
-            }
-        }
-    }
-
-    advanced_widget::operate(FindBounds {
-        target,
-        found: None,
-    })
-    .map(move |bounds| crate::Message::BoundsFound(label.clone(), bounds))
-}

src/main.rs

@@ -1,225 +0,0 @@
-//! Wayland layer-shell status bar built on `iced` + `iced_layershell`.
-
-mod bounds;
-mod module;
-mod modules;
-
-use iced::widget::{container, text, Row};
-use iced::{window, Alignment, Element, Length, Rectangle, Task, Theme};
-use iced_layershell::daemon;
-use iced_layershell::reexport::{Anchor, PopupAnchor, PopupGravity};
-use iced_layershell::settings::{LayerShellSettings, Settings, StartMode};
-use iced_layershell::to_layer_message;
-
-use crate::module::{ModuleMsg, ModuleState, MODULES};
-
-/// Height of the bar in logical pixels.
-const BAR_HEIGHT: u32 = 36;
-
-const POPUP_W: u32 = 150;
-const POPUP_H: u32 = 100;
-
-/// Vertical gap (logical px) between the bar's bottom edge and the popup.
-const POPUP_GAP: i32 = 32;
-
-struct Bar {
-    /// Which button triggered the open popup? None = closed. Keyed by module label.
-    active_popup: Option<String>,
-    /// Surface ID of the currently open popup (for removal).
-    popup_id: Option<window::Id>,
-    /// Live module states, in registry order.
-    modules: Vec<Box<dyn ModuleState>>,
-}
-
-impl Default for Bar {
-    fn default() -> Self {
-        Self {
-            active_popup: None,
-            popup_id: None,
-            modules: MODULES.iter().map(|m| m.new_state()).collect(),
-        }
-    }
-}
-
-#[to_layer_message(multi)]
-#[derive(Debug, Clone)]
-enum Message {
-    Noop,
-    ModuleClicked(String),
-    BoundsFound(String, Rectangle),
-    ClosePopup(window::Id),
-    Module(String, Box<dyn ModuleMsg>),
-}
-
-fn namespace() -> String {
-    String::from("barbar")
-}
-
-fn main() -> Result<(), iced_layershell::Error> {
-    let start_mode = match std::env::args().nth(1) {
-        Some(output) => StartMode::TargetScreen(output),
-        None => StartMode::Active,
-    };
-
-    daemon(Bar::default, namespace, update, view)
-        .style(style)
-        .subscription(subscription)
-        .settings(Settings {
-            layer_settings: LayerShellSettings {
-                size: Some((0, BAR_HEIGHT)),
-                exclusive_zone: BAR_HEIGHT as i32,
-                anchor: Anchor::Top | Anchor::Left | Anchor::Right,
-                start_mode,
-                ..Default::default()
-            },
-            ..Default::default()
-        })
-        .run()
-}
-
-/// Folds module subscriptions into one daemon subscription.
-fn subscription(bar: &Bar) -> iced::Subscription<Message> {
-    iced::Subscription::batch(bar.modules.iter().flat_map(|m| m.subscriptions()))
-}
-
-fn update(bar: &mut Bar, msg: Message) -> Task<Message> {
-    match msg {
-        Message::ModuleClicked(label) => {
-            // Toggle: close if already open, else open.
-            if bar.active_popup.as_deref() == Some(label.as_str()) {
-                return maybe_close_popup(bar);
-            }
-
-            // Query the widget tree for the module's actual laid-out bounds.
-            // The resulting `BoundsFound` message opens the popup there.
-            bounds::capture_bounds(label)
-        }
-
-        Message::BoundsFound(label, bounds) => {
-            bar.active_popup = Some(label.clone());
-
-            // Anchor rect = the button's bounds, extended below the bar so the
-            // `Bottom` anchor point (bottom-center) sits POPUP_GAP below the
-            // button's bottom edge. With `Bottom` gravity the popup grows
-            // downward from there, leaving a gap under the bar.
-            let (x, y, w, h) = (
-                bounds.x.round() as i32,
-                bounds.y.round() as i32,
-                bounds.width.round() as i32,
-                bounds.height.round() as i32,
-            );
-            let anchor_rect = (x, y, w, h + POPUP_GAP);
-            let settings = iced_layershell::actions::IcedNewPopupSettings::on_current_surface(
-                (POPUP_W, POPUP_H),
-                anchor_rect,
-            )
-            .anchor(PopupAnchor::Bottom)
-            .gravity(PopupGravity::Bottom);
-
-            let (id, task) = Message::popup_open(settings);
-            bar.popup_id = Some(id);
-
-            task
-        }
-
-        Message::Module(label, msg) => {
-            let state = bar
-                .modules
-                .iter_mut()
-                .find(|m| m.label() == label)
-                .expect("unknown module label");
-            state.handle(msg)
-        }
-
-        Message::ClosePopup(id) => {
-            if bar.popup_id == Some(id) {
-                bar.popup_id = None;
-                bar.active_popup = None;
-            }
-            Task::done(Message::RemoveWindow(id))
-        }
-
-        Message::Noop => Task::none(),
-
-        // Forward multi-window mutations to their internal handlers.
-        Message::AnchorChange { .. }
-        | Message::SetInputRegion { .. }
-        | Message::AnchorSizeChange { .. }
-        | Message::LayerChange { .. }
-        | Message::MarginChange { .. }
-        | Message::SizeChange { .. }
-        | Message::ExclusiveZoneChange { .. }
-        | Message::KeyboardInteractivityChange { .. }
-        | Message::NewBaseWindow { .. }
-        | Message::NewInputPanel { .. }
-        | Message::NewLayerShell { .. }
-        | Message::NewMenu { .. }
-        | Message::NewPopUp { .. }
-        | Message::RemoveWindow(_)
-        | Message::ForgetLastOutput
-        | Message::VirtualKeyboardPressed { .. } => Task::none(),
-    }
-}
-
-fn maybe_close_popup(bar: &mut Bar) -> Task<Message> {
-    if let Some(id) = bar.popup_id.take() {
-        bar.active_popup = None;
-        return Task::done(Message::RemoveWindow(id));
-    }
-    Task::none()
-}
-
-/// Dispatch view by which surface is being rendered.
-fn view(bar: &Bar, id: window::Id) -> Element<'_, Message> {
-    if bar.popup_id == Some(id) {
-        popup_view(bar)
-    } else {
-        bar_view(bar)
-    }
-}
-
-/// Main bar widget tree.
-fn bar_view(bar: &Bar) -> Element<'static, Message> {
-    let mut children: Vec<Element<Message>> = Vec::new();
-
-    for (i, module) in bar.modules.iter().enumerate() {
-        children.push(module.button());
-        if i < bar.modules.len() - 1 {
-            children.push(text("|").size(14).into());
-        }
-    }
-
-    container(
-        Row::from_vec(children)
-            .width(Length::Fill)
-            .align_y(Alignment::Center),
-    )
-    .padding(8)
-    .align_x(Alignment::Center)
-    .into()
-}
-
-/// Popup widget tree. Rendered on its own floating LayerShell surface.
-fn popup_view(bar: &Bar) -> Element<'static, Message> {
-    let label = bar
-        .active_popup
-        .as_ref()
-        .expect("popup open without active module");
-    let popup_id = bar.popup_id.expect("popup open without surface id");
-
-    let module = bar
-        .modules
-        .iter()
-        .find(|m| m.label() == label)
-        .expect("unknown module label");
-
-    module.popup(popup_id)
-}
-
-fn style(_bar: &Bar, theme: &Theme) -> iced::theme::Style {
-    use iced::theme::Style;
-    Style {
-        background_color: theme.palette().background,
-        text_color: theme.palette().text,
-    }
-}

src/module.rs

@@ -1,84 +0,0 @@
-use std::any::Any;
-use std::fmt::Debug;
-
-use iced::widget::{container, mouse_area, text, Id};
-use iced::{window, Alignment, Element, Length, Subscription, Task};
-
-use crate::Message;
-
-/// A module's own message type, boxed for transport through [`Message::Module`].
-pub trait ModuleMsg: Any + Debug + Send + 'static {
-    fn clone_box(&self) -> Box<dyn ModuleMsg>;
-}
-
-impl Clone for Box<dyn ModuleMsg> {
-    fn clone(&self) -> Self {
-        self.clone_box()
-    }
-}
-
-impl<T: Any + Debug + Clone + Send + 'static> ModuleMsg for T {
-    fn clone_box(&self) -> Box<dyn ModuleMsg> {
-        Box::new((*self).clone())
-    }
-}
-
-/// Downcast a boxed module message to a concrete type.
-pub fn downcast<T: Any>(boxed: Box<dyn ModuleMsg>) -> Result<Box<T>, ()> {
-    let erased: Box<dyn Any> = boxed;
-    match erased.downcast::<T>() {
-        Ok(t) => Ok(t),
-        Err(_) => Err(()),
-    }
-}
-
-/// Static module definition: how to construct the live state.
-pub trait ModuleDef: Send + Sync {
-    fn new_state(&self) -> Box<dyn ModuleState>;
-}
-
-/// Live, object-safe module state held by the bar.
-pub trait ModuleState: Send + 'static {
-    /// Stable label used as widget-tree id and message routing key.
-    fn label(&self) -> &'static str;
-
-    /// Stable widget-tree id used for popup bounds capture.
-    fn id(&self) -> Id {
-        Id::from(self.label().to_string())
-    }
-
-    /// Render the module's clickable bar segment.
-    fn button(&self) -> Element<'static, Message> {
-        container(
-            mouse_area(text(self.label()).size(14))
-                .on_press(Message::ModuleClicked(self.label().to_string())),
-        )
-        .id(self.id())
-        .into()
-    }
-
-    /// Handle a message routed to this module.
-    fn handle(&mut self, msg: Box<dyn ModuleMsg>) -> Task<Message>;
-
-    /// Render the popup body when this module's popup is open.
-    fn popup(&self, popup_id: window::Id) -> Element<'static, Message> {
-        let _ = popup_id;
-        text(format!("{} menu", self.label()))
-            .size(14)
-            .width(Length::Fill)
-            .align_x(Alignment::Center)
-            .into()
-    }
-
-    /// Subscriptions this module wants to run.
-    fn subscriptions(&self) -> Vec<Subscription<Message>> {
-        Vec::new()
-    }
-}
-
-/// Registry of all bar modules, in display order.
-pub static MODULES: &[&'static dyn ModuleDef] = &[
-    &crate::modules::workspaces::Workspaces,
-    &crate::modules::clock::Clock,
-    &crate::modules::system::System,
-];

src/modules/clock.rs

@@ -1,50 +0,0 @@
-use iced::widget::{column, mouse_area, text};
-use iced::{window, Alignment, Element, Length};
-
-use crate::module::{ModuleDef, ModuleMsg, ModuleState};
-use crate::Message;
-
-pub struct Clock;
-
-pub struct State;
-
-impl ModuleDef for Clock {
-    fn new_state(&self) -> Box<dyn ModuleState> {
-        Box::new(State)
-    }
-}
-
-impl ModuleState for State {
-    fn label(&self) -> &'static str {
-        "clock"
-    }
-
-    // ponytail: clock has no internal messages yet; the tick subscription
-    // that gives it live time is the upgrade path (add `Msg` + `update`
-    // here when needed).
-    fn handle(&mut self, _msg: Box<dyn ModuleMsg>) -> iced::Task<Message> {
-        iced::Task::none()
-    }
-
-    fn popup(&self, popup_id: window::Id) -> Element<'static, Message> {
-        let items: Vec<Element<'static, Message>> = ["Time format", "Date display"]
-            .into_iter()
-            .map(|label| {
-                mouse_area(text(label).size(13))
-                    .on_press(Message::ClosePopup(popup_id))
-                    .into()
-            })
-            .collect();
-
-        column![
-            text("clock menu")
-                .size(14)
-                .width(Length::Fill)
-                .align_x(Alignment::Center),
-            column(items).spacing(1),
-            mouse_area(text("close").size(12)).on_press(Message::ClosePopup(popup_id)),
-        ]
-        .spacing(1)
-        .into()
-    }
-}

src/modules/mod.rs

@@ -1,3 +0,0 @@
-pub mod clock;
-pub mod system;
-pub mod workspaces;

src/modules/system.rs

@@ -1,49 +0,0 @@
-use iced::widget::{column, mouse_area, text};
-use iced::{window, Alignment, Element, Length};
-
-use crate::module::{ModuleDef, ModuleMsg, ModuleState};
-use crate::Message;
-
-pub struct System;
-
-pub struct State;
-
-impl ModuleDef for System {
-    fn new_state(&self) -> Box<dyn ModuleState> {
-        Box::new(State)
-    }
-}
-
-impl ModuleState for State {
-    fn label(&self) -> &'static str {
-        "system"
-    }
-
-    // ponytail: no internal messages yet; real brightness/volume/power
-    // actions (each with its own `Msg` variant) are the upgrade path.
-    fn handle(&mut self, _msg: Box<dyn ModuleMsg>) -> iced::Task<Message> {
-        iced::Task::none()
-    }
-
-    fn popup(&self, popup_id: window::Id) -> Element<'static, Message> {
-        let items: Vec<Element<'static, Message>> = ["Brightness", "Volume", "Power"]
-            .into_iter()
-            .map(|label| {
-                mouse_area(text(label).size(13))
-                    .on_press(Message::ClosePopup(popup_id))
-                    .into()
-            })
-            .collect();
-
-        column![
-            text("system menu")
-                .size(14)
-                .width(Length::Fill)
-                .align_x(Alignment::Center),
-            column(items).spacing(1),
-            mouse_area(text("close").size(12)).on_press(Message::ClosePopup(popup_id)),
-        ]
-        .spacing(1)
-        .into()
-    }
-}

src/modules/workspaces.rs

@@ -1,66 +0,0 @@
-use iced::widget::{column, mouse_area, text, Row};
-use iced::{window, Alignment, Element, Length, Task};
-
-use crate::module::{downcast, ModuleDef, ModuleMsg, ModuleState};
-use crate::Message;
-
-pub struct Workspaces;
-
-pub struct State {
-    workspaces: Vec<String>,
-}
-
-#[derive(Debug, Clone)]
-pub enum Msg {
-    Select(String),
-}
-
-impl ModuleDef for Workspaces {
-    fn new_state(&self) -> Box<dyn ModuleState> {
-        Box::new(State {
-            workspaces: vec!["1".into(), "2".into(), "3".into(), "4".into()],
-        })
-    }
-}
-
-impl ModuleState for State {
-    fn label(&self) -> &'static str {
-        "workspaces"
-    }
-
-    fn handle(&mut self, msg: Box<dyn ModuleMsg>) -> Task<Message> {
-        let msg = *downcast::<Msg>(msg).expect("workspaces module received foreign message");
-        match msg {
-            Msg::Select(ws) => {
-                self.workspaces.sort_by_key(|w| w != &ws);
-                Task::none()
-            }
-        }
-    }
-
-    fn popup(&self, popup_id: window::Id) -> Element<'static, Message> {
-        let items: Vec<Element<'static, Message>> = self
-            .workspaces
-            .iter()
-            .map(|ws| {
-                mouse_area(text(ws.clone()).size(13))
-                    .on_press(Message::Module(
-                        "workspaces".into(),
-                        Box::new(Msg::Select(ws.clone())),
-                    ))
-                    .into()
-            })
-            .collect();
-
-        column![
-            text("workspaces menu")
-                .size(14)
-                .width(Length::Fill)
-                .align_x(Alignment::Center),
-            Row::from_vec(items).spacing(1),
-            mouse_area(text("close").size(12)).on_press(Message::ClosePopup(popup_id)),
-        ]
-        .spacing(1)
-        .into()
-    }
-}

test.toml

@@ -0,0 +1,31 @@
+[display]
+monitor = "DP-2"
+height = 20
+antialiasing = true
+default_text_size = 14.0
+padding = 4.0
+spacing = 8.0
+theme = 'example_base16.yaml'
+
+[order]
+left = ["workspaces", "weather"]
+middle = []
+right = ["battery", "audio", "clock"]
+
+[modules.clock]
+show_seconds = false
+
+[modules.workspaces]
+# Slots rendered, left to right (workspaces 1..=count).
+count = 10
+# Horizontal gap between slots, logical px.
+gap = 3.0
+# Slot size, logical px.
+slot_w = 10.0
+slot_h = 17.0
+# Corner radius.
+radius = 2.5
+# Visual scale per state (focused / exists / absent).
+scale_active = 1.0
+scale_exists = 0.85
+scale_absent = 0.65