textual-rs

A Rust TUI framework inspired by Python Textual, delivering modern terminal interfaces with CSS styling, reactive state, and rich widgets.

Features

Widgets (25+)

Styling

• CSS/TCSS engine -- type, class, and ID selectors with cascade and specificity
• Theme variables -- $primary, $surface, $accent, with shade generation ($primary-lighten-2, $accent-darken-1)
• 7 built-in themes -- textual-dark, textual-light, tokyo-night, nord, gruvbox, dracula, catppuccin
• Runtime theme switching -- Ctrl+T to cycle themes
• 8 border styles -- ascii, blank, double, heavy, inner, outer, round, tall (McGugan Box)
• Box model -- padding, margin, min/max width/height, flex grow
• Pseudo-classes -- :focus, :hover with automatic visual feedback
• Custom themes -- override any variable via user CSS

Layout

• Flexbox via Taffy -- layout-direction: vertical | horizontal, flex-grow, align-items, justify-content
• Dock -- dock: top | bottom | left | right for fixed chrome
• Responsive -- recomputes on terminal resize

Interaction

• Mouse -- click, hover tracking, scroll wheel, right-click context menus
• Mouse capture stack -- push/pop mouse-enabled state; Shift+click bypasses capture for native text selection
• Keyboard -- key bindings, Tab/Shift+Tab focus cycling, Ctrl+C/X/V clipboard
• Focus system -- visible focus indicators with border color changes

Reactive State

• Reactive<T> -- property wrapper that triggers re-renders on change
• Signals -- built on reactive_graph (from Leptos); ArcRwSignal / ArcMemo
• Message passing -- typed async messages bubble up the widget tree

Background Work

• Worker API -- run_worker() and run_worker_with_progress() for async tasks off the UI thread
• Command palette -- register commands via CommandRegistry, invoke with Ctrl+P

Animation

• Tween system -- easing functions (linear, ease-in-out-cubic, ease-out-cubic)
• Built-in animations -- Switch toggle slide, Tab underline slide
• 30fps render tick -- ratatui diff makes unchanged frames nearly free

Rendering

• Sub-cell graphics -- half-block, eighth-block, quadrant, and braille characters
• McGugan Box borders -- thin tall borders using Unicode block elements
• Terminal capability detection -- color depth, Unicode support auto-detected

Testing

• TestApp -- headless application harness, no terminal needed
• Pilot -- simulated keyboard/mouse input for integration tests
• Snapshot testing -- insta-based plain-text buffer snapshots
• 21 visual regression tests included

Cross-platform

• Windows 10+, macOS, Linux
• ratatui 0.30 + crossterm 0.29 backend
• Stable Rust (no nightly required), MSRV 1.88

Quick Start

[dependencies]
textual-rs = "0.1"

use textual_rs::{App, Widget, Label, Button, Header, Footer};
use textual_rs::widget::context::AppContext;
use ratatui::buffer::Buffer;
use ratatui::layout::Rect;

struct MyScreen;

impl Widget for MyScreen {
    fn widget_type_name(&self) -> &'static str { "MyScreen" }
    fn compose(&self) -> Vec<Box<dyn Widget>> {
        vec![
            Box::new(Header::new("My App")),
            Box::new(Label::new("Hello, textual-rs!")),
            Box::new(Button::new("Click Me")),
            Box::new(Footer),
        ]
    }
    fn render(&self, _ctx: &AppContext, _area: Rect, _buf: &mut Buffer) {}
}

fn main() -> anyhow::Result<()> {
    let mut app = App::new(|| Box::new(MyScreen))
        .with_css("MyScreen { layout-direction: vertical; background: $background; color: $foreground; }");
    app.run()
}

Styling with CSS

Screen {
    background: $background;
    color: $foreground;
}

Button {
    border: inner;
    min-width: 16;
    height: 3;
    background: $surface;
    color: $foreground;
}

Button.primary {
    background: $primary;
    color: #ffffff;
}

*:focus {
    border: tall $accent;
}

Examples

cargo run --example demo                  # Widget showcase (4 tabs)
cargo run --example irc_demo              # IRC client demo
cargo run --example tutorial_01_hello     # Hello world
cargo run --example tutorial_02_layout    # Layout system
cargo run --example tutorial_03_events    # Event handling
cargo run --example tutorial_04_reactive  # Reactive state
cargo run --example tutorial_05_workers   # Background workers

Documentation

• User Guide -- complete walkthrough
• CSS Reference -- all properties, selectors, theme variables

License

MIT