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Ratatui

Demo

This is the original demo example from the main README. It is available for each of the backends.

run
git clone https://github.com/ratatui/ratatui.git --branch latest
cd ratatui
cargo run --example=demo --features=crossterm
cargo run --example=demo --no-default-features --features=termion
cargo run --example=demo --no-default-features --features=termwiz

demo

demo/main.rs
//! # [Ratatui] Original Demo example
//!
//! The latest version of this example is available in the [examples] folder in the repository.
//!
//! Please note that the examples are designed to be run against the `main` branch of the Github
//! repository. This means that you may not be able to compile with the latest release version on
//! crates.io, or the one that you have installed locally.
//!
//! See the [examples readme] for more information on finding examples that match the version of the
//! library you are using.
//!
//! [Ratatui]: https://github.com/ratatui/ratatui
//! [examples]: https://github.com/ratatui/ratatui/blob/main/examples
//! [examples readme]: https://github.com/ratatui/ratatui/blob/main/examples/README.md


use std::{error::Error, time::Duration};


use argh::FromArgs;


mod app;
#[cfg(feature = "crossterm")]
mod crossterm;
#[cfg(all(not(windows), feature = "termion"))]
mod termion;
#[cfg(feature = "termwiz")]
mod termwiz;


mod ui;


/// Demo
#[derive(Debug, FromArgs)]
struct Cli {
    /// time in ms between two ticks.
    #[argh(option, default = "250")]
    tick_rate: u64,
    /// whether unicode symbols are used to improve the overall look of the app
    #[argh(option, default = "true")]
    enhanced_graphics: bool,
}


fn main() -> Result<(), Box<dyn Error>> {
    let cli: Cli = argh::from_env();
    let tick_rate = Duration::from_millis(cli.tick_rate);
    #[cfg(feature = "crossterm")]
    crate::crossterm::run(tick_rate, cli.enhanced_graphics)?;
    #[cfg(all(not(windows), feature = "termion", not(feature = "crossterm")))]
    crate::termion::run(tick_rate, cli.enhanced_graphics)?;
    #[cfg(all(
        feature = "termwiz",
        not(feature = "crossterm"),
        not(feature = "termion")
    ))]
    crate::termwiz::run(tick_rate, cli.enhanced_graphics)?;
    Ok(())
}
demo/app.rs
use rand::{
    distributions::{Distribution, Uniform},
    rngs::ThreadRng,
};
use ratatui::widgets::ListState;


const TASKS: [&str; 24] = [
    "Item1", "Item2", "Item3", "Item4", "Item5", "Item6", "Item7", "Item8", "Item9", "Item10",
    "Item11", "Item12", "Item13", "Item14", "Item15", "Item16", "Item17", "Item18", "Item19",
    "Item20", "Item21", "Item22", "Item23", "Item24",
];


const LOGS: [(&str, &str); 26] = [
    ("Event1", "INFO"),
    ("Event2", "INFO"),
    ("Event3", "CRITICAL"),
    ("Event4", "ERROR"),
    ("Event5", "INFO"),
    ("Event6", "INFO"),
    ("Event7", "WARNING"),
    ("Event8", "INFO"),
    ("Event9", "INFO"),
    ("Event10", "INFO"),
    ("Event11", "CRITICAL"),
    ("Event12", "INFO"),
    ("Event13", "INFO"),
    ("Event14", "INFO"),
    ("Event15", "INFO"),
    ("Event16", "INFO"),
    ("Event17", "ERROR"),
    ("Event18", "ERROR"),
    ("Event19", "INFO"),
    ("Event20", "INFO"),
    ("Event21", "WARNING"),
    ("Event22", "INFO"),
    ("Event23", "INFO"),
    ("Event24", "WARNING"),
    ("Event25", "INFO"),
    ("Event26", "INFO"),
];


const EVENTS: [(&str, u64); 24] = [
    ("B1", 9),
    ("B2", 12),
    ("B3", 5),
    ("B4", 8),
    ("B5", 2),
    ("B6", 4),
    ("B7", 5),
    ("B8", 9),
    ("B9", 14),
    ("B10", 15),
    ("B11", 1),
    ("B12", 0),
    ("B13", 4),
    ("B14", 6),
    ("B15", 4),
    ("B16", 6),
    ("B17", 4),
    ("B18", 7),
    ("B19", 13),
    ("B20", 8),
    ("B21", 11),
    ("B22", 9),
    ("B23", 3),
    ("B24", 5),
];


#[derive(Clone)]
pub struct RandomSignal {
    distribution: Uniform<u64>,
    rng: ThreadRng,
}


impl RandomSignal {
    pub fn new(lower: u64, upper: u64) -> Self {
        Self {
            distribution: Uniform::new(lower, upper),
            rng: rand::thread_rng(),
        }
    }
}


impl Iterator for RandomSignal {
    type Item = u64;
    fn next(&mut self) -> Option<u64> {
        Some(self.distribution.sample(&mut self.rng))
    }
}


#[derive(Clone)]
pub struct SinSignal {
    x: f64,
    interval: f64,
    period: f64,
    scale: f64,
}


impl SinSignal {
    pub const fn new(interval: f64, period: f64, scale: f64) -> Self {
        Self {
            x: 0.0,
            interval,
            period,
            scale,
        }
    }
}


impl Iterator for SinSignal {
    type Item = (f64, f64);
    fn next(&mut self) -> Option<Self::Item> {
        let point = (self.x, (self.x * 1.0 / self.period).sin() * self.scale);
        self.x += self.interval;
        Some(point)
    }
}


pub struct TabsState<'a> {
    pub titles: Vec<&'a str>,
    pub index: usize,
}


impl<'a> TabsState<'a> {
    pub const fn new(titles: Vec<&'a str>) -> Self {
        Self { titles, index: 0 }
    }
    pub fn next(&mut self) {
        self.index = (self.index + 1) % self.titles.len();
    }


    pub fn previous(&mut self) {
        if self.index > 0 {
            self.index -= 1;
        } else {
            self.index = self.titles.len() - 1;
        }
    }
}


pub struct StatefulList<T> {
    pub state: ListState,
    pub items: Vec<T>,
}


impl<T> StatefulList<T> {
    pub fn with_items(items: Vec<T>) -> Self {
        Self {
            state: ListState::default(),
            items,
        }
    }


    pub fn next(&mut self) {
        let i = match self.state.selected() {
            Some(i) => {
                if i >= self.items.len() - 1 {
                    0
                } else {
                    i + 1
                }
            }
            None => 0,
        };
        self.state.select(Some(i));
    }


    pub fn previous(&mut self) {
        let i = match self.state.selected() {
            Some(i) => {
                if i == 0 {
                    self.items.len() - 1
                } else {
                    i - 1
                }
            }
            None => 0,
        };
        self.state.select(Some(i));
    }
}


pub struct Signal<S: Iterator> {
    source: S,
    pub points: Vec<S::Item>,
    tick_rate: usize,
}


impl<S> Signal<S>
where
    S: Iterator,
{
    fn on_tick(&mut self) {
        self.points.drain(0..self.tick_rate);
        self.points
            .extend(self.source.by_ref().take(self.tick_rate));
    }
}


pub struct Signals {
    pub sin1: Signal<SinSignal>,
    pub sin2: Signal<SinSignal>,
    pub window: [f64; 2],
}


impl Signals {
    fn on_tick(&mut self) {
        self.sin1.on_tick();
        self.sin2.on_tick();
        self.window[0] += 1.0;
        self.window[1] += 1.0;
    }
}


pub struct Server<'a> {
    pub name: &'a str,
    pub location: &'a str,
    pub coords: (f64, f64),
    pub status: &'a str,
}


pub struct App<'a> {
    pub title: &'a str,
    pub should_quit: bool,
    pub tabs: TabsState<'a>,
    pub show_chart: bool,
    pub progress: f64,
    pub sparkline: Signal<RandomSignal>,
    pub tasks: StatefulList<&'a str>,
    pub logs: StatefulList<(&'a str, &'a str)>,
    pub signals: Signals,
    pub barchart: Vec<(&'a str, u64)>,
    pub servers: Vec<Server<'a>>,
    pub enhanced_graphics: bool,
}


impl<'a> App<'a> {
    pub fn new(title: &'a str, enhanced_graphics: bool) -> Self {
        let mut rand_signal = RandomSignal::new(0, 100);
        let sparkline_points = rand_signal.by_ref().take(300).collect();
        let mut sin_signal = SinSignal::new(0.2, 3.0, 18.0);
        let sin1_points = sin_signal.by_ref().take(100).collect();
        let mut sin_signal2 = SinSignal::new(0.1, 2.0, 10.0);
        let sin2_points = sin_signal2.by_ref().take(200).collect();
        App {
            title,
            should_quit: false,
            tabs: TabsState::new(vec!["Tab0", "Tab1", "Tab2"]),
            show_chart: true,
            progress: 0.0,
            sparkline: Signal {
                source: rand_signal,
                points: sparkline_points,
                tick_rate: 1,
            },
            tasks: StatefulList::with_items(TASKS.to_vec()),
            logs: StatefulList::with_items(LOGS.to_vec()),
            signals: Signals {
                sin1: Signal {
                    source: sin_signal,
                    points: sin1_points,
                    tick_rate: 5,
                },
                sin2: Signal {
                    source: sin_signal2,
                    points: sin2_points,
                    tick_rate: 10,
                },
                window: [0.0, 20.0],
            },
            barchart: EVENTS.to_vec(),
            servers: vec![
                Server {
                    name: "NorthAmerica-1",
                    location: "New York City",
                    coords: (40.71, -74.00),
                    status: "Up",
                },
                Server {
                    name: "Europe-1",
                    location: "Paris",
                    coords: (48.85, 2.35),
                    status: "Failure",
                },
                Server {
                    name: "SouthAmerica-1",
                    location: "São Paulo",
                    coords: (-23.54, -46.62),
                    status: "Up",
                },
                Server {
                    name: "Asia-1",
                    location: "Singapore",
                    coords: (1.35, 103.86),
                    status: "Up",
                },
            ],
            enhanced_graphics,
        }
    }


    pub fn on_up(&mut self) {
        self.tasks.previous();
    }


    pub fn on_down(&mut self) {
        self.tasks.next();
    }


    pub fn on_right(&mut self) {
        self.tabs.next();
    }


    pub fn on_left(&mut self) {
        self.tabs.previous();
    }


    pub fn on_key(&mut self, c: char) {
        match c {
            'q' => {
                self.should_quit = true;
            }
            't' => {
                self.show_chart = !self.show_chart;
            }
            _ => {}
        }
    }


    pub fn on_tick(&mut self) {
        // Update progress
        self.progress += 0.001;
        if self.progress > 1.0 {
            self.progress = 0.0;
        }


        self.sparkline.on_tick();
        self.signals.on_tick();


        let log = self.logs.items.pop().unwrap();
        self.logs.items.insert(0, log);


        let event = self.barchart.pop().unwrap();
        self.barchart.insert(0, event);
    }
}
demo/ui.rs
use ratatui::{
    layout::{Constraint, Layout, Rect},
    style::{Color, Modifier, Style},
    symbols,
    text::{self, Span},
    widgets::{
        canvas::{self, Canvas, Circle, Map, MapResolution, Rectangle},
        Axis, BarChart, Block, Cell, Chart, Dataset, Gauge, LineGauge, List, ListItem, Paragraph,
        Row, Sparkline, Table, Tabs, Wrap,
    },
    Frame,
};


use crate::app::App;


pub fn draw(frame: &mut Frame, app: &mut App) {
    let chunks = Layout::vertical([Constraint::Length(3), Constraint::Min(0)]).split(frame.area());
    let tabs = app
        .tabs
        .titles
        .iter()
        .map(|t| text::Line::from(Span::styled(*t, Style::default().fg(Color::Green))))
        .collect::<Tabs>()
        .block(Block::bordered().title(app.title))
        .highlight_style(Style::default().fg(Color::Yellow))
        .select(app.tabs.index);
    frame.render_widget(tabs, chunks[0]);
    match app.tabs.index {
        0 => draw_first_tab(frame, app, chunks[1]),
        1 => draw_second_tab(frame, app, chunks[1]),
        2 => draw_third_tab(frame, app, chunks[1]),
        _ => {}
    };
}


fn draw_first_tab(frame: &mut Frame, app: &mut App, area: Rect) {
    let chunks = Layout::vertical([
        Constraint::Length(9),
        Constraint::Min(8),
        Constraint::Length(7),
    ])
    .split(area);
    draw_gauges(frame, app, chunks[0]);
    draw_charts(frame, app, chunks[1]);
    draw_text(frame, chunks[2]);
}


fn draw_gauges(frame: &mut Frame, app: &mut App, area: Rect) {
    let chunks = Layout::vertical([
        Constraint::Length(2),
        Constraint::Length(3),
        Constraint::Length(2),
    ])
    .margin(1)
    .split(area);
    let block = Block::bordered().title("Graphs");
    frame.render_widget(block, area);


    let label = format!("{:.2}%", app.progress * 100.0);
    let gauge = Gauge::default()
        .block(Block::new().title("Gauge:"))
        .gauge_style(
            Style::default()
                .fg(Color::Magenta)
                .bg(Color::Black)
                .add_modifier(Modifier::ITALIC | Modifier::BOLD),
        )
        .use_unicode(app.enhanced_graphics)
        .label(label)
        .ratio(app.progress);
    frame.render_widget(gauge, chunks[0]);


    let sparkline = Sparkline::default()
        .block(Block::new().title("Sparkline:"))
        .style(Style::default().fg(Color::Green))
        .data(&app.sparkline.points)
        .bar_set(if app.enhanced_graphics {
            symbols::bar::NINE_LEVELS
        } else {
            symbols::bar::THREE_LEVELS
        });
    frame.render_widget(sparkline, chunks[1]);


    let line_gauge = LineGauge::default()
        .block(Block::new().title("LineGauge:"))
        .filled_style(Style::default().fg(Color::Magenta))
        .line_set(if app.enhanced_graphics {
            symbols::line::THICK
        } else {
            symbols::line::NORMAL
        })
        .ratio(app.progress);
    frame.render_widget(line_gauge, chunks[2]);
}


#[allow(clippy::too_many_lines)]
fn draw_charts(frame: &mut Frame, app: &mut App, area: Rect) {
    let constraints = if app.show_chart {
        vec![Constraint::Percentage(50), Constraint::Percentage(50)]
    } else {
        vec![Constraint::Percentage(100)]
    };
    let chunks = Layout::horizontal(constraints).split(area);
    {
        let chunks = Layout::vertical([Constraint::Percentage(50), Constraint::Percentage(50)])
            .split(chunks[0]);
        {
            let chunks =
                Layout::horizontal([Constraint::Percentage(50), Constraint::Percentage(50)])
                    .split(chunks[0]);


            // Draw tasks
            let tasks: Vec<ListItem> = app
                .tasks
                .items
                .iter()
                .map(|i| ListItem::new(vec![text::Line::from(Span::raw(*i))]))
                .collect();
            let tasks = List::new(tasks)
                .block(Block::bordered().title("List"))
                .highlight_style(Style::default().add_modifier(Modifier::BOLD))
                .highlight_symbol("> ");
            frame.render_stateful_widget(tasks, chunks[0], &mut app.tasks.state);


            // Draw logs
            let info_style = Style::default().fg(Color::Blue);
            let warning_style = Style::default().fg(Color::Yellow);
            let error_style = Style::default().fg(Color::Magenta);
            let critical_style = Style::default().fg(Color::Red);
            let logs: Vec<ListItem> = app
                .logs
                .items
                .iter()
                .map(|&(evt, level)| {
                    let s = match level {
                        "ERROR" => error_style,
                        "CRITICAL" => critical_style,
                        "WARNING" => warning_style,
                        _ => info_style,
                    };
                    let content = vec![text::Line::from(vec![
                        Span::styled(format!("{level:<9}"), s),
                        Span::raw(evt),
                    ])];
                    ListItem::new(content)
                })
                .collect();
            let logs = List::new(logs).block(Block::bordered().title("List"));
            frame.render_stateful_widget(logs, chunks[1], &mut app.logs.state);
        }


        let barchart = BarChart::default()
            .block(Block::bordered().title("Bar chart"))
            .data(&app.barchart)
            .bar_width(3)
            .bar_gap(2)
            .bar_set(if app.enhanced_graphics {
                symbols::bar::NINE_LEVELS
            } else {
                symbols::bar::THREE_LEVELS
            })
            .value_style(
                Style::default()
                    .fg(Color::Black)
                    .bg(Color::Green)
                    .add_modifier(Modifier::ITALIC),
            )
            .label_style(Style::default().fg(Color::Yellow))
            .bar_style(Style::default().fg(Color::Green));
        frame.render_widget(barchart, chunks[1]);
    }
    if app.show_chart {
        let x_labels = vec![
            Span::styled(
                format!("{}", app.signals.window[0]),
                Style::default().add_modifier(Modifier::BOLD),
            ),
            Span::raw(format!(
                "{}",
                (app.signals.window[0] + app.signals.window[1]) / 2.0
            )),
            Span::styled(
                format!("{}", app.signals.window[1]),
                Style::default().add_modifier(Modifier::BOLD),
            ),
        ];
        let datasets = vec![
            Dataset::default()
                .name("data2")
                .marker(symbols::Marker::Dot)
                .style(Style::default().fg(Color::Cyan))
                .data(&app.signals.sin1.points),
            Dataset::default()
                .name("data3")
                .marker(if app.enhanced_graphics {
                    symbols::Marker::Braille
                } else {
                    symbols::Marker::Dot
                })
                .style(Style::default().fg(Color::Yellow))
                .data(&app.signals.sin2.points),
        ];
        let chart = Chart::new(datasets)
            .block(
                Block::bordered().title(Span::styled(
                    "Chart",
                    Style::default()
                        .fg(Color::Cyan)
                        .add_modifier(Modifier::BOLD),
                )),
            )
            .x_axis(
                Axis::default()
                    .title("X Axis")
                    .style(Style::default().fg(Color::Gray))
                    .bounds(app.signals.window)
                    .labels(x_labels),
            )
            .y_axis(
                Axis::default()
                    .title("Y Axis")
                    .style(Style::default().fg(Color::Gray))
                    .bounds([-20.0, 20.0])
                    .labels([
                        Span::styled("-20", Style::default().add_modifier(Modifier::BOLD)),
                        Span::raw("0"),
                        Span::styled("20", Style::default().add_modifier(Modifier::BOLD)),
                    ]),
            );
        frame.render_widget(chart, chunks[1]);
    }
}


fn draw_text(frame: &mut Frame, area: Rect) {
    let text = vec![
        text::Line::from("This is a paragraph with several lines. You can change style your text the way you want"),
        text::Line::from(""),
        text::Line::from(vec![
            Span::from("For example: "),
            Span::styled("under", Style::default().fg(Color::Red)),
            Span::raw(" "),
            Span::styled("the", Style::default().fg(Color::Green)),
            Span::raw(" "),
            Span::styled("rainbow", Style::default().fg(Color::Blue)),
            Span::raw("."),
        ]),
        text::Line::from(vec![
            Span::raw("Oh and if you didn't "),
            Span::styled("notice", Style::default().add_modifier(Modifier::ITALIC)),
            Span::raw(" you can "),
            Span::styled("automatically", Style::default().add_modifier(Modifier::BOLD)),
            Span::raw(" "),
            Span::styled("wrap", Style::default().add_modifier(Modifier::REVERSED)),
            Span::raw(" your "),
            Span::styled("text", Style::default().add_modifier(Modifier::UNDERLINED)),
            Span::raw(".")
        ]),
        text::Line::from(
            "One more thing is that it should display unicode characters: 10€"
        ),
    ];
    let block = Block::bordered().title(Span::styled(
        "Footer",
        Style::default()
            .fg(Color::Magenta)
            .add_modifier(Modifier::BOLD),
    ));
    let paragraph = Paragraph::new(text).block(block).wrap(Wrap { trim: true });
    frame.render_widget(paragraph, area);
}


fn draw_second_tab(frame: &mut Frame, app: &mut App, area: Rect) {
    let chunks =
        Layout::horizontal([Constraint::Percentage(30), Constraint::Percentage(70)]).split(area);
    let up_style = Style::default().fg(Color::Green);
    let failure_style = Style::default()
        .fg(Color::Red)
        .add_modifier(Modifier::RAPID_BLINK | Modifier::CROSSED_OUT);
    let rows = app.servers.iter().map(|s| {
        let style = if s.status == "Up" {
            up_style
        } else {
            failure_style
        };
        Row::new(vec![s.name, s.location, s.status]).style(style)
    });
    let table = Table::new(
        rows,
        [
            Constraint::Length(15),
            Constraint::Length(15),
            Constraint::Length(10),
        ],
    )
    .header(
        Row::new(vec!["Server", "Location", "Status"])
            .style(Style::default().fg(Color::Yellow))
            .bottom_margin(1),
    )
    .block(Block::bordered().title("Servers"));
    frame.render_widget(table, chunks[0]);


    let map = Canvas::default()
        .block(Block::bordered().title("World"))
        .paint(|ctx| {
            ctx.draw(&Map {
                color: Color::White,
                resolution: MapResolution::High,
            });
            ctx.layer();
            ctx.draw(&Rectangle {
                x: 0.0,
                y: 30.0,
                width: 10.0,
                height: 10.0,
                color: Color::Yellow,
            });
            ctx.draw(&Circle {
                x: app.servers[2].coords.1,
                y: app.servers[2].coords.0,
                radius: 10.0,
                color: Color::Green,
            });
            for (i, s1) in app.servers.iter().enumerate() {
                for s2 in &app.servers[i + 1..] {
                    ctx.draw(&canvas::Line {
                        x1: s1.coords.1,
                        y1: s1.coords.0,
                        y2: s2.coords.0,
                        x2: s2.coords.1,
                        color: Color::Yellow,
                    });
                }
            }
            for server in &app.servers {
                let color = if server.status == "Up" {
                    Color::Green
                } else {
                    Color::Red
                };
                ctx.print(
                    server.coords.1,
                    server.coords.0,
                    Span::styled("X", Style::default().fg(color)),
                );
            }
        })
        .marker(if app.enhanced_graphics {
            symbols::Marker::Braille
        } else {
            symbols::Marker::Dot
        })
        .x_bounds([-180.0, 180.0])
        .y_bounds([-90.0, 90.0]);
    frame.render_widget(map, chunks[1]);
}


fn draw_third_tab(frame: &mut Frame, _app: &mut App, area: Rect) {
    let chunks = Layout::horizontal([Constraint::Ratio(1, 2), Constraint::Ratio(1, 2)]).split(area);
    let colors = [
        Color::Reset,
        Color::Black,
        Color::Red,
        Color::Green,
        Color::Yellow,
        Color::Blue,
        Color::Magenta,
        Color::Cyan,
        Color::Gray,
        Color::DarkGray,
        Color::LightRed,
        Color::LightGreen,
        Color::LightYellow,
        Color::LightBlue,
        Color::LightMagenta,
        Color::LightCyan,
        Color::White,
    ];
    let items: Vec<Row> = colors
        .iter()
        .map(|c| {
            let cells = vec![
                Cell::from(Span::raw(format!("{c:?}: "))),
                Cell::from(Span::styled("Foreground", Style::default().fg(*c))),
                Cell::from(Span::styled("Background", Style::default().bg(*c))),
            ];
            Row::new(cells)
        })
        .collect();
    let table = Table::new(
        items,
        [
            Constraint::Ratio(1, 3),
            Constraint::Ratio(1, 3),
            Constraint::Ratio(1, 3),
        ],
    )
    .block(Block::bordered().title("Colors"));
    frame.render_widget(table, chunks[0]);
}
demo/crossterm.rs
use std::{
    error::Error,
    io,
    time::{Duration, Instant},
};


use ratatui::{
    backend::{Backend, CrosstermBackend},
    crossterm::{
        event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyEventKind},
        execute,
        terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
    },
    Terminal,
};


use crate::{app::App, ui};


pub fn run(tick_rate: Duration, enhanced_graphics: bool) -> Result<(), Box<dyn Error>> {
    // setup terminal
    enable_raw_mode()?;
    let mut stdout = io::stdout();
    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
    let backend = CrosstermBackend::new(stdout);
    let mut terminal = Terminal::new(backend)?;


    // create app and run it
    let app = App::new("Crossterm Demo", enhanced_graphics);
    let app_result = run_app(&mut terminal, app, tick_rate);


    // restore terminal
    disable_raw_mode()?;
    execute!(
        terminal.backend_mut(),
        LeaveAlternateScreen,
        DisableMouseCapture
    )?;
    terminal.show_cursor()?;


    if let Err(err) = app_result {
        println!("{err:?}");
    }


    Ok(())
}


fn run_app<B: Backend>(
    terminal: &mut Terminal<B>,
    mut app: App,
    tick_rate: Duration,
) -> io::Result<()> {
    let mut last_tick = Instant::now();
    loop {
        terminal.draw(|frame| ui::draw(frame, &mut app))?;


        let timeout = tick_rate.saturating_sub(last_tick.elapsed());
        if event::poll(timeout)? {
            if let Event::Key(key) = event::read()? {
                if key.kind == KeyEventKind::Press {
                    match key.code {
                        KeyCode::Left | KeyCode::Char('h') => app.on_left(),
                        KeyCode::Up | KeyCode::Char('k') => app.on_up(),
                        KeyCode::Right | KeyCode::Char('l') => app.on_right(),
                        KeyCode::Down | KeyCode::Char('j') => app.on_down(),
                        KeyCode::Char(c) => app.on_key(c),
                        _ => {}
                    }
                }
            }
        }
        if last_tick.elapsed() >= tick_rate {
            app.on_tick();
            last_tick = Instant::now();
        }
        if app.should_quit {
            return Ok(());
        }
    }
}
demo/termion.rs
#![allow(dead_code)]
use std::{error::Error, io, sync::mpsc, thread, time::Duration};


use ratatui::{
    backend::{Backend, TermionBackend},
    termion::{
        event::Key,
        input::{MouseTerminal, TermRead},
        raw::IntoRawMode,
        screen::IntoAlternateScreen,
    },
    Terminal,
};


use crate::{app::App, ui};


pub fn run(tick_rate: Duration, enhanced_graphics: bool) -> Result<(), Box<dyn Error>> {
    // setup terminal
    let stdout = io::stdout()
        .into_raw_mode()
        .unwrap()
        .into_alternate_screen()
        .unwrap();
    let stdout = MouseTerminal::from(stdout);
    let backend = TermionBackend::new(stdout);
    let mut terminal = Terminal::new(backend)?;


    // create app and run it
    let app = App::new("Termion demo", enhanced_graphics);
    run_app(&mut terminal, app, tick_rate)?;


    Ok(())
}


fn run_app<B: Backend>(
    terminal: &mut Terminal<B>,
    mut app: App,
    tick_rate: Duration,
) -> Result<(), Box<dyn Error>> {
    let events = events(tick_rate);
    loop {
        terminal.draw(|frame| ui::draw(frame, &mut app))?;


        match events.recv()? {
            Event::Input(key) => match key {
                Key::Up | Key::Char('k') => app.on_up(),
                Key::Down | Key::Char('j') => app.on_down(),
                Key::Left | Key::Char('h') => app.on_left(),
                Key::Right | Key::Char('l') => app.on_right(),
                Key::Char(c) => app.on_key(c),
                _ => {}
            },
            Event::Tick => app.on_tick(),
        }
        if app.should_quit {
            return Ok(());
        }
    }
}


enum Event {
    Input(Key),
    Tick,
}


fn events(tick_rate: Duration) -> mpsc::Receiver<Event> {
    let (tx, rx) = mpsc::channel();
    let keys_tx = tx.clone();
    thread::spawn(move || {
        let stdin = io::stdin();
        for key in stdin.keys().flatten() {
            if let Err(err) = keys_tx.send(Event::Input(key)) {
                eprintln!("{err}");
                return;
            }
        }
    });
    thread::spawn(move || loop {
        if let Err(err) = tx.send(Event::Tick) {
            eprintln!("{err}");
            break;
        }
        thread::sleep(tick_rate);
    });
    rx
}
demo/termwiz.rs
#![allow(dead_code)]
use std::{
    error::Error,
    time::{Duration, Instant},
};


use ratatui::{
    backend::TermwizBackend,
    termwiz::{
        input::{InputEvent, KeyCode},
        terminal::Terminal as TermwizTerminal,
    },
    Terminal,
};


use crate::{app::App, ui};


pub fn run(tick_rate: Duration, enhanced_graphics: bool) -> Result<(), Box<dyn Error>> {
    let backend = TermwizBackend::new()?;
    let mut terminal = Terminal::new(backend)?;
    terminal.hide_cursor()?;


    // create app and run it
    let app = App::new("Termwiz Demo", enhanced_graphics);
    let app_result = run_app(&mut terminal, app, tick_rate);


    terminal.show_cursor()?;
    terminal.flush()?;


    if let Err(err) = app_result {
        println!("{err:?}");
    }


    Ok(())
}


fn run_app(
    terminal: &mut Terminal<TermwizBackend>,
    mut app: App,
    tick_rate: Duration,
) -> Result<(), Box<dyn Error>> {
    let mut last_tick = Instant::now();
    loop {
        terminal.draw(|frame| ui::draw(frame, &mut app))?;


        let timeout = tick_rate.saturating_sub(last_tick.elapsed());
        if let Some(input) = terminal
            .backend_mut()
            .buffered_terminal_mut()
            .terminal()
            .poll_input(Some(timeout))?
        {
            match input {
                InputEvent::Key(key_code) => match key_code.key {
                    KeyCode::UpArrow | KeyCode::Char('k') => app.on_up(),
                    KeyCode::DownArrow | KeyCode::Char('j') => app.on_down(),
                    KeyCode::LeftArrow | KeyCode::Char('h') => app.on_left(),
                    KeyCode::RightArrow | KeyCode::Char('l') => app.on_right(),
                    KeyCode::Char(c) => app.on_key(c),
                    _ => {}
                },
                InputEvent::Resized { cols, rows } => {
                    terminal
                        .backend_mut()
                        .buffered_terminal_mut()
                        .resize(cols, rows);
                }
                _ => {}
            }
        }


        if last_tick.elapsed() >= tick_rate {
            app.on_tick();
            last_tick = Instant::now();
        }
        if app.should_quit {
            return Ok(());
        }
    }
}