Redland

A Wayland screen color temperature adjuster with automatic day/night cycle support, written in Rust. Similar to wlsunset and Redshift, but with a modern Rust implementation and optional QML-based system tray UI.

Features

• Automatic color temperature adjustment based on sunrise/sunset times
• Multiple location methods: GeoClue2, manual coordinates, or fixed times
• Smooth transitions between day and night temperatures
• Manual mode override (Day/Night/Sunset/Auto) with automatic expiration
• IPC control via JSONL stdin/stdout for UI integration
• System tray UI using Quickshell (optional)
• Wayland native using wlr-gamma-control-unstable-v1 protocol

Requirements

• Wayland compositor with wlr-gamma-control-unstable-v1 support (e.g., Sway, Hyprland, river)
• Rust toolchain (edition 2024)
• GeoClue2 (optional, for automatic location detection)
• Quickshell (optional, for system tray UI)

Building

# Using cargo directly
cargo build --release

# Or with devenv (if using Nix)
devenv shell -- cargo build --release

The binary will be available at target/release/redland.

Usage

Basic Usage

Run with automatic location detection (via GeoClue2):

redland

Manual Coordinates

Specify latitude and longitude to skip GeoClue:

redland --lat 45.0 --lon 15.0

Fixed Sunrise/Sunset Times

Use manual times (HH:MM format) instead of calculated sunrise/sunset:

redland --sunrise 06:30 --sunset 18:00

Custom Temperature Range

Adjust the temperature range (default: 4000K night, 6500K day):

redland --low 3000 --high 6500

Transition Duration

Set transition duration around sunrise/sunset (default: 1800 seconds):

redland --duration 3600

Start in Specific Mode

redland --mode day    # Force day mode
redland --mode night  # Force night mode
redland --mode auto   # Automatic (default)

System Tray UI

The included QML-based system tray provides visual mode control:

quickshell -c redland-ui.qml

Features:

• Icon showing current mode (☀️ day, 🌙 night, 🌅 sunset)
• Superscript "A" indicator for automatic mode
• Popup menu for mode selection
• Real-time temperature display

Note: Edit redland-ui.qml and update the daemon path to match your installation.

IPC Protocol

Redland uses a JSON-line protocol over stdin/stdout for UI integration. The daemon is typically spawned by the UI (e.g., redland-ui.qml) and controlled by writing JSONL commands to its stdin and reading responses from stdout.

Commands

Get Status:

{"type":"get_status"}

Set Mode:

{"type":"set_mode","mode":"night"}

Valid modes: auto, day, night, sunset

Set Temperature Range:

{"type":"set_temperature","low":3000,"high":6500}

Response Format

{
  "type": "status",
  "requested_mode": "auto",
  "current_mode": "day",
  "automatic_mode": "day",
  "current_temp": 6500,
  "low_temp": 4000,
  "high_temp": 6500,
  "location": [45.0, 15.0],
  "sun_times": ["06:30", "18:00"]
}

Command-Line Options

Options:
  -o, --output <OUTPUT>        Name/description of outputs to target (can repeat)
  -t, --low <LOW_TEMP>         Low color temperature at night (K) [default: 4000]
  -T, --high <HIGH_TEMP>       High color temperature at day (K) [default: 6500]
  -l, --lat <LATITUDE>         Latitude (degrees)
  -L, --lon <LONGITUDE>        Longitude (degrees)
  -S, --sunrise <SUNRISE>      Manual sunrise time HH:MM (local)
  -s, --sunset <SUNSET>        Manual sunset time HH:MM (local)
  -d, --duration <DURATION>    Transition duration in seconds [default: 1800]
      --mode <MODE>            Operating mode [default: auto] [possible values: auto, day, night, sunset]
  -h, --help                   Print help
  -V, --version                Print version

How It Works

1. Location Detection: Uses GeoClue2 D-Bus service, manual coordinates, or fixed times
2. Sunrise/Sunset Calculation: Computes solar events using astronomical algorithms
3. Phase Detection: Determines current phase (Night/Sunrise/Day/Sunset)
4. Temperature Calculation: Interpolates between low and high temperatures during transitions
5. Gamma Adjustment: Applies color temperature via Wayland gamma control protocol
6. Mode Override: Manual mode selection expires at next sunrise, returning to automatic

Day Phases

• Night: Before dawn or after dusk
• Sunrise: Transition period before sunrise (gradual warming)
• Day: Between sunrise and sunset (high temperature)
• Sunset: Transition period after sunset (gradual cooling)

License

See the source code for license information.

Acknowledgments

Inspired by wlsunset and Redshift.