LMTT - Linux Multi-Theme Toggle

High-performance, async theme switching for Hyprland/Wayland desktops with Material You color schemes.

Features

• ⚡ Blazing Fast: Async Rust implementation, modules run in parallel
• 🎨 Flexible Theming: Material You colors from wallpapers (via matugen), custom JSON colors, or built-in fallback themes
• 🔌 Modular: Supports 14+ applications (Waybar, Hyprland, VSCode, Wezterm, SwayNC, etc.)
• 🎯 Auto-Detection: Only applies themes to installed applications
• 🔧 Easy Setup: Auto-injects config includes with lmtt setup
• 🧹 Clean Uninstall: lmtt cleanup removes all injected config
• ⚙️ Highly Configurable: TOML config at ~/.config/lmtt/config.toml
• 🔔 Desktop Notifications: Optional notifications for theme changes

Installation

Arch Linux

Add the [mason] repo to /etc/pacman.conf, then install:

[mason]
SigLevel = Optional TrustAll
Server = https://masonrhodesdev.github.io/arch-repo/x86_64

sudo pacman -Sy lmtt

Fedora

sudo dnf copr enable solaris765/lmtt
sudo dnf install lmtt

Optional Runtime Dependencies

• matugen - Optional, for wallpaper-based color generation
  • If not installed, LMTT uses built-in Material You fallback themes
  • Can also use custom JSON color files
• GTK 3/4 applications (optional, for gsettings integration)

Build from Source

Requires Rust 1.70+ (rustup recommended):

git clone https://github.com/MasonRhodesDev/linux-multi-theme-toggle.git
cd linux-multi-theme-toggle
sudo make install PREFIX=/usr

This installs both binaries (lmtt, lmtt-config) plus the config example and custom-module examples under /usr/share/lmtt/.

Quick Start

1. Initialize config:

   lmtt init

2. Edit config at ~/.config/lmtt/config.toml:

   [general]
   wallpaper = "~/Pictures/your-wallpaper.png"

3. Run setup (auto-configures app config files):

   lmtt setup

4. Switch theme:

   lmtt switch         # Toggle between light/dark
   lmtt switch dark    # Switch to dark mode
   lmtt switch light   # Switch to light mode

Usage

Configuration Manager (Interactive TUI)

Launch the interactive configuration manager:

lmtt config

Every setting is editable from one screen:

The schema-driven TUI has three sections:

• General - wallpaper, default_mode, scheme_type, use_matugen, default color files, with Notifications / Performance / Cache / Logging as subsections
• Light Profile - GTK/icon/cursor themes, fonts, VSCode theme, opacity, blur for light mode
• Dark Profile - the same settings for dark mode

Modules are not toggled from the TUI — enable or disable one by editing [modules.<name>] enabled = false in ~/.config/lmtt/config.toml (modules are otherwise auto-skipped when their app isn't installed).

Controls:

• Tab/←→/h/l - Switch between sections
• ↑↓ or j/k - Navigate items
• Space/Enter - Toggle boolean values
• e - Open full config in $EDITOR
• q/Esc - Quit

Changes are saved immediately to ~/.config/lmtt/config.toml.

Commands

# Switch theme
lmtt switch                   # Toggle between light/dark
lmtt switch dark              # Switch to dark mode
lmtt switch light             # Switch to light mode
lmtt switch --no-notify       # Toggle without notifications

# Interactive configuration
lmtt config                   # TUI for managing all settings

# Setup mode (configure app configs)
lmtt setup
lmtt setup --dry-run

# Cleanup mode (remove lmtt config injections)
lmtt cleanup
lmtt cleanup --module waybar  # Cleanup specific module
lmtt cleanup --dry-run

# Status and info
lmtt status
lmtt list
lmtt list --all

Configuration

Config file: ~/.config/lmtt/config.toml

[general]
wallpaper = "~/Pictures/forrest.png"
default_mode = "dark"
scheme_type = "scheme-tonal-spot"
use_matugen = true  # Set to false to use fallback/custom colors
default_light_colors = "~/.config/lmtt/colors-light.json"
default_dark_colors = "~/.config/lmtt/colors-dark.json"

[notifications]
enabled = true
timeout = 5000

[modules.waybar]
enabled = true

[modules.hyprland]
enabled = true

Key features:

• Modules enabled by default: Apps are auto-detected and run if installed
• Disable modules: Set enabled = false to skip specific apps
• Flexible color sources:
  • matugen (default): Generate colors from wallpaper
  • Custom JSON: Provide your own colors-light.json and colors-dark.json
  • Built-in fallback: Material You themes if matugen not available

Custom Color Schemes

Create your own color schemes by placing JSON files at ~/.config/lmtt/colors-light.json and ~/.config/lmtt/colors-dark.json:

{
  "surface": "#fbf8ff",
  "on_surface": "#1a1b23",
  "primary": "#3a6a33",
  "on_primary": "#ffffff",
  "secondary": "#7d525f",
  "error": "#ba1a1a",
  "outline": "#74767f",
  "surface_variant": "#e0e2ec",
  "on_surface_variant": "#44464f"
}

Set use_matugen = false in config to use custom colors instead of wallpaper-based generation.

Custom Modules

LMTT supports user-defined custom modules in ~/.config/lmtt/modules/ - no recompilation needed!

Three Module Types

1. Declarative (Template-based) - For simple config files:

# ~/.config/lmtt/modules/alacritty.toml
name = "alacritty"
binary = "alacritty"

[output]
path = "~/.config/alacritty/lmtt-colors.yml"

[template]
content = """
colors:
  primary:
    background: '{{surface}}'
    foreground: '{{on_surface}}'
"""

2. Script-based - For complex logic:

# ~/.config/lmtt/modules/spotify.toml
name = "spotify"
binary = "spotify"

[script]
path = "~/.config/lmtt/scripts/spotify.sh"
timeout = 10000

Custom modules are automatically discovered and loaded. See examples/modules/ for working examples (Alacritty, Kitty, Discord, Spotify) and examples/README-modules.md for full documentation.

Supported Applications

Built-in Modules (Rust)

Module	Config File	Auto-Setup
GTK	gsettings	✓
Waybar	style.css	✓
Hyprland	lmtt-colors.conf	✓
SwayNC	style.css	✓
Wezterm	lmtt-colors.lua	✓
Tmux	lmtt-colors.conf	✓
Neovim	lmtt-colors.lua	✓
VSCode	settings.json	✓
Wofi	style.css	✓
Fish	universal variables (set -U)	—

Setup Mode

lmtt setup checks your installed applications and prompts to inject config includes:

$ lmtt setup
🔧 LMTT Setup Mode
================

✓ waybar detected
  📄 /home/user/.config/waybar/style.css
     Import lmtt colors into Waybar CSS
     ⚠ Include line missing:
     @import url('../matugen/lmtt-colors.css');

     Inject this line? [Y/n/q] y
     ✓ Injected successfully!

What gets injected?

Each module adds a marked block at the top of your config:

/* >>> lmtt managed block - do not edit manually >>> */
@import url('../matugen/lmtt-colors.css');
/* <<< lmtt managed block <<< */

/* Your existing config below */

The marker comment syntax matches the file type: CSS uses /* */, Lua uses --, and conf/ini files use #.

This allows clean removal with lmtt cleanup.

Cleanup/Uninstall

Remove all lmtt-injected config lines:

# Clean all modules
lmtt cleanup

# Clean specific module
lmtt cleanup --module waybar

# Dry run (see what would be removed)
lmtt cleanup --dry-run

This is completely non-intrusive - your original config files are restored.

Architecture

Runtime pipeline for a theme switch:

flowchart TD
    CMD["lmtt switch (mode)"] --> CFG["Load config from ~/.config/lmtt/"]
    CFG --> RES{"Color resolution"}
    RES -->|"use_matugen: matugen from wallpaper (cached — skipped if wallpaper unchanged)"| SCHEME["ColorScheme"]
    RES -->|"else: custom colors-light.json / colors-dark.json"| SCHEME
    RES -->|"else: built-in Material You fallback palette"| SCHEME
    SCHEME --> REG["ModuleRegistry — inventory-discovered ThemeModule impls (17 built-ins + handlebars-templated custom modules)"]

    subgraph PAR ["apply() for every enabled module, in parallel on Tokio — whole switch ~100-200ms"]
        GTK["GTK: gsettings color-scheme + theme names"]
        HYP["Hyprland: write lmtt-colors.conf include, hyprctl reload"]
        XDG["xdg-desktop-portal: color-scheme via dbus-send"]
        APPS["config writes: Waybar / SwayNC / Wofi CSS, Wezterm / Neovim Lua, Tmux conf, VSCode settings.json, ..."]
    end

    REG --> PAR
    PAR --> NOTE["notify-send (optional)"]

Loading

lmtt/               # CLI binary
lmtt-core/          # Core types (Config, ColorScheme, Cache)
lmtt-modules/       # Theme modules (Waybar, Hyprland, etc.)
lmtt-platforms/     # Platform backends (GTK, XDG, Qt)

Adding a Custom Module

See lmtt-modules/src/waybar.rs for a template. Key points:

1. Implement ThemeModule trait
2. Specify binary_name() for auto-detection
3. Implement apply() for theme switching
4. Implement config_files() for setup mode
5. Add to ModuleRegistry in registry.rs

Performance

Typical theme switch: ~100-200ms

• Modules run in parallel (Tokio async)
• No blocking I/O
• Wallpaper color caching (skips regeneration if unchanged)

Performance warnings for slow modules (>250ms default).

Notifications

Desktop notifications are shown when the theme changes (disable with --no-notify, or [notifications] enabled = false in the config). Set show_module_progress = true for a per-module notification as each applies.

Troubleshooting

Module not running?

# Check if app is installed
lmtt list --all

# Check config
lmtt status

# Verbose output
lmtt -v switch dark

Config not applied?

# Re-run setup
lmtt setup

# Verify config file includes lmtt block
cat ~/.config/waybar/style.css

Cleanup not working?

Config files must have the lmtt marker comments. If you manually edited them, you may need to manually remove the include lines.

Migration from Bash Version

The Rust version is a drop-in replacement with improved performance:

1. Backup your current bash scripts
2. Install lmtt
3. Run lmtt init and lmtt setup
4. Test with lmtt switch dark

Your existing module configs should work without changes.

Contributing

Contributions welcome! Areas needing help:

• Additional module support (Alacritty, Kitty, etc.)
• Platform backends (KDE Plasma integration)
• Documentation improvements
• Testing on different distros

License

MIT

Credits

• matugen - Material You color generation
• Original bash implementation by Mason