GTK Decoration Plugin for Wayfire

A Wayfire plugin that provides server-side window decorations (SSDs) with native GTK3 theme integration.

Features

• Automatic GTK3 Theme Integration: Decorations automatically match your GTK theme

  • Titlebar colors from your GTK theme
  • Window borders with proper styling
  • Rounded top corners (8px radius)

• Icon Theme Support: Window control buttons use icons from your icon theme

  • Icons are properly recolored to match theme foreground colors
  • Supports SVG symbolic icons via librsvg
  • Falls back to simple drawn icons if theme icons can't be loaded

• Font Integration: Automatically uses your GTK font settings

  • Reads gtk-font-name from ~/.config/gtk-3.0/settings.ini
  • Font size scaled 1.12x to match native GTK titlebar size
  • Centered title text with proper spacing around buttons
  • Long titles truncated with ellipsis to prevent overflow

• Live Theme Reloading: Automatically detects and reloads when you change:

  • GTK theme
  • Icon theme
  • Font settings
  • No Wayfire restart required!

• Configurable:

  • Button order (left-to-right)
  • Titlebar height
  • Border size
  • Fallback colors and fonts

Configuration

Add to your ~/.config/wayfire.ini:

[core]
plugins = ... gtkdecor ...

[gtkdecor]
# Button order from left to right
button_order = close minimize maximize

# Titlebar and border sizes
title_height = 28
border_size = 4

# Fallback settings (only used if GTK theme can't be loaded)
font = sans-serif
font_color = #ffffffff
active_color = #222222aa
inactive_color = #333333dd

# View matching
ignore_views = none
forced_views = none

Requirements

• GTK 3.0 (gtk+-3.0)
• Cairo
• Pango
• librsvg 2.0 (optional, for icon theme support)

How It Works

1. Theme Loading: On first render, the plugin:

   • Reads your GTK settings from ~/.config/gtk-3.0/settings.ini
   • Extracts font family, weight, and size (e.g., "Source Sans 3 Semi-Bold 11")
   • Loads the GTK theme CSS file for colors
   • Font from settings.ini takes priority over CSS to ensure consistent rendering
   • Loads icon theme path

2. Rendering: For each window:

   • Titlebar with rounded top corners using theme colors
   • Window control buttons with icon theme icons
   • Recolored SVG icons to match theme foreground
   • Title text centered with GTK font (scaled 1.12x for proper size)
   • Long titles automatically truncated with ellipsis

3. Live Updates: Uses inotify to monitor GTK settings file

   • Detects changes to settings.ini
   • Automatically reloads all decoration themes
   • Damages windows to trigger re-render

Comparison with Original decoration Plugin

The original decoration plugin provides simple static decorations. gtkdecor extends this with:

• ✅ Native GTK theme integration (colors, fonts)
• ✅ Icon theme support for buttons
• ✅ Live theme reloading
• ✅ Better visual match with GTK applications
• ✅ Rounded corners
• ✅ Proper icon recoloring

Development

Building

The plugin is built as part of the main Wayfire build:

cd wayfire/build
ninja plugins/gtkdecor/libgtkdecor.so

Installing

sudo cp plugins/gtkdecor/libgtkdecor.so /usr/local/lib/wayfire/
sudo cp metadata/gtkdecor.xml /usr/local/share/wayfire/metadata/

File Structure

• decoration.cpp - Main plugin logic, view matching, inotify monitoring
• deco-theme.cpp/hpp - Theme parsing, GTK integration, rendering
• deco-layout.cpp/hpp - Button layout and input handling
• deco-subsurface.cpp/hpp - Scene graph integration
• deco-button.cpp/hpp - Button rendering and state management

Credits

Based on the original Wayfire decoration plugin, extended with GTK3 theme integration.

License

Same as Wayfire (MIT)

Disclaimer

This project was created with the assistance of an AI agent. I do not have great expertise in C++, so the code has not really been reviewed. Anyone using or extending this project should independently verify its correctness, safety, and suitability for their use case.

Screenshot