breadbar/README.md

breadbar

Minimal status bar and notification daemon for Hyprland on Wayland.

A single Rust binary that provides a full-width top bar and a standards-compliant D-Bus notification daemon, with no system tray, no launcher, and no wallpaper logic.

Features

Status bar (anchored to the top of every monitor via gtk4-layer-shell):

• Left: live workspace buttons sourced from Hyprland IPC, active workspace highlighted
• Centre: clock (HH:MM, updates at the top of each minute)
• Right: CPU%, RAM, power draw (W), battery level + AC indicator, Bluetooth state, WiFi SSID with signal strength

Notification daemon:

• Implements org.freedesktop.Notifications (D-Bus) — works with any standard notification sender (notify-send, etc.)
• Popups appear top-right, stack vertically, auto-dismiss after the sender-specified timeout (default 5 s)
• Supports CloseNotification

Theming:

• Reads ~/.cache/wal/colors.json (pywal) on startup for a palette that matches your wallpaper
• Falls back to a Catppuccin Mocha palette if pywal is not present
• User CSS override: ~/.config/breadbar/style.css
• Send SIGHUP to reload the theme at runtime (integrates with wallpaper-change hooks)

Dependencies

Runtime:

• GTK4 (≥ 4.12)
• gtk4-layer-shell
• iw — for WiFi SSID/signal (iw dev <iface> link)
• A running Hyprland compositor
• D-Bus session bus

Bluetooth status is read from /sys/class/rfkill and BlueZ D-Bus; it degrades gracefully if unavailable.

Building

cargo build --release

The binary is at target/release/breadbar.

Requirements: Rust 1.77+ (uses LazyLock), a GTK4 development environment (libgtk-4-dev / gtk4 package).

On Arch Linux:

sudo pacman -S gtk4 gtk4-layer-shell iw
cargo build --release

Running

./target/release/breadbar

Typically launched from your Hyprland config:

exec-once = /path/to/breadbar

breadbar claims org.freedesktop.Notifications on the session D-Bus on startup. If another notification daemon is already running, startup will fail — stop the other daemon first.

Theming

pywal integration

breadbar reads ~/.cache/wal/colors.json automatically. To reload after a wallpaper change:

pkill -HUP breadbar

Or hook it into your wallpaper script:

wal -i /path/to/wallpaper.jpg
pkill -HUP breadbar

Custom CSS

Drop a ~/.config/breadbar/style.css file and send SIGHUP to reload. This CSS is applied at a higher priority than the pywal palette so you can override anything.

Example — change the font size:

* {
    font-size: 13px;
}

Architecture

Module	Responsibility
src/main.rs	GTK4 app entry point, widget tree, relm4 component
src/bar/workspaces.rs	Hyprland IPC event stream, workspace buttons
src/bar/clock.rs	Minute-tick clock
src/bar/stats.rs	Polling loop: CPU, RAM, power, battery, Bluetooth, WiFi
src/notifications/mod.rs	org.freedesktop.Notifications zbus service
src/notifications/popup.rs	Layer-shell popup window and card stack
src/theme.rs	pywal reader, GTK CSS provider injection

Stats are polled every 2 seconds. Bluetooth and WiFi are sampled every 16 seconds and cached in between to avoid hammering D-Bus and iw.

License

MIT