lv-tui

A reactive TUI framework for Rust. Component tree, reactive state, CSS-like styling, event bubbling, focus management — everything you need to build complex terminal applications.

use lv_tui::prelude::*;
use lv_tui::Component;

#[derive(Component)]
struct Counter {
    #[reactive(paint, copy)]
    count: i32,
}

impl Counter {
    fn new() -> Self { Self { count: 0 } }
}

impl Component for Counter {
    fn render(&self, cx: &mut RenderCx) {
        cx.line(format!("count: {}", self.get_count()));
        cx.line("press + to increment, q to quit");
    }

    fn event(&mut self, event: &Event, cx: &mut EventCx) {
        if event.is_key(Key::Char('+')) { self.set_count(self.get_count() + 1, cx); }
        if event.is_key(Key::Char('q')) { cx.quit(); }
    }
}

fn main() -> lv_tui::Result<()> {
    App::new(Counter::new()).run()
}

Features

• Component tree — compose UIs with Column, Row, Stack, Block, Scroll, Overlay
• Reactive state — #[reactive(paint)] auto-triggers repaint on change
• Event bubbling — Capture → Target → Bubble with stop_propagation()
• Focus management — Tab/Shift+Tab navigation with Focus/Blur events
• CSS-like stylesheets — type/class/id selectors with style inheritance
• Unicode — CJK/Emoji wide characters, text wrap, truncation, alignment
• Async tasks — cx.spawn() for background work with TaskComplete events
• Debug view — press d to visualize component borders and labels

Widgets

Text System

All widgets accept impl Into<Text>, giving you three levels of control:

use lv_tui::prelude::*;

// Simple: plain text
Label::new("hello")

// Styled: use Stylize trait
Label::new(Line::from(vec![
    "Error: ".red().bold(),
    Span::new("not found"),
]))

// Multi-line: build Text from Lines
Label::new(Text::from(vec![
    Line::from(Span::new("Title").bold()),
    Line::from(Span::new("Body")),
]))

Getting Started

Quick example

Create a settings form with checkboxes, radio group, and keyboard navigation:

use lv_tui::prelude::*;
use lv_tui::widgets::*;

struct App { content: Column }

impl App {
    fn new() -> Self {
        Self {
            content: Column::new()
                .child(Label::new("Settings").style(Style::default().bold()))
                .child(Label::new(""))
                .child(Checkbox::new("Enable notifications"))
                .child(Checkbox::new("Auto-save").checked())
                .child(Label::new(""))
                .child(Label::new("Theme:"))
                .child(RadioGroup::new(vec![
                    "Light".into(), "Dark".into(), "System".into(),
                ]))
                .child(Label::new(""))
                .child(Label::new("Tab: switch  Space: toggle  q: quit")
                    .style(Style::default().fg(Color::Gray))),
        }
    }
}

impl Component for App {
    fn render(&self, cx: &mut RenderCx) { self.content.render(cx); }
    fn event(&mut self, e: &Event, cx: &mut EventCx) {
        if e.is_key(Key::Char('q')) { cx.quit(); return; }
        self.content.event(e, cx);
    }
    fn layout(&mut self, r: lv_tui::geom::Rect, cx: &mut lv_tui::component::LayoutCx) { self.content.layout(r, cx); }
    fn measure(&self, c: lv_tui::layout::Constraint, _cx: &mut lv_tui::component::MeasureCx) -> lv_tui::geom::Size {
        lv_tui::geom::Size { width: c.max.width, height: c.max.height }
    }
    fn focusable(&self) -> bool { false }
}

fn main() -> lv_tui::Result<()> {
    lv_tui::app::App::new(App::new()).run()
}

Theme support

use lv_tui::prelude::*;

fn main() -> lv_tui::Result<()> {
    set_theme(Theme::Light); // or Theme::Dark (default)
    // ... rest of app
}

Clipboard

fn event(&mut self, event: &Event, cx: &mut EventCx) {
    // Copy selected text to system clipboard (OSC 52)
    cx.copy_to_clipboard("copied text");
}

[dependencies]
lv-tui = "0.3"

cargo run --example counter
cargo run --example demo_app

License

MIT