kswitch

A simple command line tool for light/dark theme switching in KDE Plasma.

Features

• Command line interface to set or toggle theme
• Easy to configure a keyboard shortcut — just make a keyboard shortcut for kswitch toggle
• Configurable through a simple config file (~/.config/kswitch/config.toml by default)
• Switches Konsole default theme and also updates theme for all open Konsole instances
• Synchronous, multithreaded design for smoother transitions

Installation Instructions

Dependencies

• KDE Plasma (tested on 6.3.5)
• dbus and qdbus for interfacing with KDE components
• Rust (for building from source)
• cargo for installation

From Source

git clone https://github.com/yourusername/kswitch
cd kswitch
cargo install --path .

Usage

kswitch toggle         # Toggle between light and dark themes
kswitch set light      # Force light mode
kswitch set dark       # Force dark mode
kswitch config edit    # Open config in your default editor

You can create a custom keyboard shortcut in KDE System Settings to run kswitch toggle.

Configuration

kswitch uses a simple TOML config file located at:

~/.config/kswitch/config.toml

It includes paths and names of your preferred themes, wallpapers, etc. The config can be created or edited via:

kswitch config edit

Warnings

• Currently tested only on KDE Plasma 6.3.5 (Manjaro Linux).
• Functionality may vary or break on other Plasma versions or KDE-based environments.
• Use at your own risk and backup your theme settings.

Tasks

• CLI interface
• Set
  • Global Theme
  • Terminal
    • Set default theme in .config/konsolerc
    • Set theme for existing terminal windows via D-Bus
  • Color Scheme
  • Wallpaper
  • Cursor Theme
  • Kvantum engine theme (for Qt apps)
  • Environment variable setting to track light/dark state
• Get
  • Current state from environment variable
  • Default theme based on time and config
• Set Themes
  • Light
  • Dark
• Toggle
• Config
  • Config struct
    • Read from file
    • Save to file
    • Edit via default editor
  • Auto-create at default location

Future Improvements

• Interactive configuration tool
• Improve speed of synchronous switching
• Prioritize visible windows during theme switch
• Implement timed changes via systemctl and systemd timers
• Create custom wallpaper plugin using QML/Plasmoid for transition effects
• Add support for user-defined scripts:
  • ~/.config/kswitch/light.sh
  • ~/.config/kswitch/dark.sh
• Allow disabling individual features (e.g., don't change wallpaper)
• Replace binary dependencies with full D-Bus control
• Automatic scheduling based on user config
• Sunrise/sunset-based scheduling using sunrise

License

MIT License. See LICENSE file for details.

Contributions

Feel free to open issues or submit pull requests. Cannot promise I will look at them. Did this for myself to help learn Rust.

Existing solutions

Take a look at koi and YinYang. These do similar things, but there is no way to create a keyboard shortcut in Koi, and YinYang feels slow. Neither offer theme switching on Konsole sessions.