Rui — A GTK4 UI Designer for Rust

Status: Early Foundation — This project is being built as a starting point, not a long-term commitment. If you find it useful and want to take it further, we're actively looking for contributors and future maintainers.

Rui (said like "Rooey" — R for Rust + UI) is a native GTK4 application for visually designing .ui files used by GTK/Libadwaita Rust applications. It aims to be the missing GUI builder in the Rust desktop ecosystem.

What It Does (v0.3)

Editor

• Tabbed editor with syntax highlighting (GtkSourceView 5) for .ui, .rs, .py, .js, .ts, .sh, and HTML/CSS
• File tree sidebar and minimap
• Find & Replace with regex, Go to Line
• Undo/Redo — full designer history with crash recovery
• Session persistence (remembers open files and layout)
• Built-in dark theme (Catppuccin Mocha); follows system GTK theme

GTK4 UI Designer

• Live Canvas — renders .ui XML in a side pane as you type (500 ms debounce)
• Widget Palette — 30+ GTK4 widgets across 5 categories, click to insert XML
• Property Inspector — edit widget properties visually, writes back to XML in real-time
• GtkGrid Designer — right-click to set column/row/span; merge-mode (select cells → apply span)
• Drag & Drop — drag widgets on the canvas to reorder; drag from palette to insert
• Code Generation — emit idiomatic Rust signal handler stubs from .ui files
• Template Library — reusable UI snippets to jump-start new layouts
• New Project Dialog — scaffold a project with grid dimension input (rows × cols)

Build & Run

• Run scripts directly from the editor (F5) — Python, JavaScript, TypeScript, Rust, Shell, HTML/CSS
• Build Rust projects (cargo build --release) with a cargo check pre-flight that catches errors before the full build
• Build Install — builds a release binary and generates a .desktop launcher + icon for system installation
• Stop button (Shift+F5) to kill a running process

AI Integration

• Claude Code Panel — embedded Claude Code assistant with live .ui + companion .rs context; apply code blocks directly to files
• API AI Chat Panel — multi-provider chat (OpenAI, Anthropic, Gemini, OpenAI-compat); streams responses with Apply buttons; configured via ⚙ gear button

Layouts

• Code View (Ctrl+1) — full sidebar, editor with minimap, no canvas
• Designer View (Ctrl+2) — canvas + toolbox front and centre, narrow sidebar
• All panels toggleable independently (sidebar, output, canvas, toolbox, preview, minimap)

Building

# Prerequisites: GTK4, GtkSourceView 5, WebKitGTK 6 (optional)
# On Arch:    sudo pacman -S gtk4 gtksourceview5 webkitgtk-6.0
# On Fedora:  sudo dnf install gtk4-devel gtksourceview5-devel webkit2gtk6.0-devel
# On Ubuntu:  sudo apt install libgtk-4-dev libgtksourceview-5-dev libwebkitgtk-6.0-dev

cargo build --release
# Binary at target/release/rui

Without WebKit (disables AI chat panel and HTML preview):

cargo build --release --no-default-features

Or use the provided script which checks dependencies and installs the binary, icon, and desktop entry:

./build.sh

Configuration

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

[editor]
font = "Monospace 12"
show_line_numbers = true
tab_width = 4
color_scheme = "rui-theme"
show_minimap = true
autosave = false

Available colour schemes: rui-theme, classic, oblivion, solarized-dark, solarized-light, kate, tango, cobalt.

License

MIT — see LICENSE.

Contributing

Contributions welcome! See ARCHITECTURE.md for the module layout. The codebase is intentionally simple — one binary crate, no macros, straightforward GTK4.

If you're interested in becoming a maintainer, open an issue.