Skip to content

CLAUDE.md

Latest commit

 

History

History
68 lines (49 loc) · 2.56 KB

CLAUDE.md

File metadata and controls

68 lines (49 loc) · 2.56 KB
Raw

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Build Commands

cargo build --release          # Build optimized binary
cargo run                      # Run in debug mode
cargo clippy                   # Lint
cargo publish --allow-dirty    # Publish to crates.io

AUR package: kb-layout-daemon-git

Testing the Daemon

The daemon requires the user to be in the input group. For testing without logout:

sg input -c "./target/release/kb-layout-daemon"

Control via D-Bus:

dbus-send --session --print-reply --dest=org.kblayout.Daemon /org/kblayout/Daemon org.kblayout.Daemon.GetMode
dbus-send --session --print-reply --dest=org.kblayout.Daemon /org/kblayout/Daemon org.kblayout.Daemon.ToggleMode
dbus-send --session --print-reply --dest=org.kblayout.Daemon /org/kblayout/Daemon org.kblayout.Daemon.SetMode string:"passive"

Architecture

Single-binary daemon with one main.rs file (~445 lines). Key components:

Global State (atomics)

  • GRAB_MODE: AtomicBool - Current mode (grab vs passive)
  • CURRENT_LAYOUT: AtomicU32 - Tracks active keyboard layout index

Threading Model

  • Main thread: Initializes config, finds keyboards, spawns monitor threads
  • One thread per physical keyboard: Runs monitor_keyboard() loop
  • D-Bus service thread: Runs async tokio runtime for org.kblayout.Daemon

Two Operating Modes

  • Grab mode: Exclusive device access via EVIOCGRAB, events forwarded through uinput virtual keyboard. Ensures correct layout on first keystroke (~1ms latency).
  • Passive mode: No device grabbing, just monitors events. Zero latency but first key after switch may use old layout.

Key Functions

  • load_config() - Reads ~/.config/kb-layout-daemon/config.toml
  • find_keyboards() - Scans /dev/input/event* matching config names
  • monitor_keyboard() - Per-keyboard event loop (grab/read/forward)
  • create_virtual_keyboard() - Creates uinput device with KEY, MSC_SCAN, and REL axes
  • switch_layout() - D-Bus call to org.kde.keyboard to change layout

Virtual Keyboard Requirements The virtual keyboard must include MSC_SCAN events and relative axes, otherwise some keys won't work in grab mode.

Config Location

~/.config/kb-layout-daemon/config.toml

Find keyboard device names with:

cat /proc/bus/input/devices | grep -A 4 "Name="

KDE Plasma Widget

Located in widget/ directory. Install to ~/.local/share/plasma/plasmoids/org.kblayout.toggle/. Uses Plasma5Support.DataSource with "executable" engine to run D-Bus commands.