ratatui/examples/crossterm_demo.rs

#[allow(dead_code)]
mod demo;
#[allow(dead_code)]
mod util;

use std::sync::mpsc;
use std::thread;
use std::time::Duration;

use crossterm::{input, AlternateScreen, InputEvent, KeyEvent};
use structopt::StructOpt;
use tui::backend::CrosstermBackend;
use tui::Terminal;

use crate::demo::{ui, App};
use std::io::stdout;

enum Event<I> {
    Input(I),
    Tick,
}

#[derive(Debug, StructOpt)]
struct Cli {
    #[structopt(long = "tick-rate", default_value = "250")]
    tick_rate: u64,
    #[structopt(long = "log")]
    log: bool,
}

fn main() -> Result<(), failure::Error> {
    let cli = Cli::from_args();
    stderrlog::new().quiet(!cli.log).verbosity(4).init()?;

    let screen = AlternateScreen::to_alternate(true)?;
    let backend = CrosstermBackend::with_alternate_screen(stdout(), screen)?;
    let mut terminal = Terminal::new(backend)?;
    terminal.hide_cursor()?;

    // Setup input handling
    let (tx, rx) = mpsc::channel();
    {
        let tx = tx.clone();
        thread::spawn(move || {
            let input = input();
            let reader = input.read_sync();
            for event in reader {
                match event {
                    InputEvent::Keyboard(key) => {
                        if let Err(_) = tx.send(Event::Input(key.clone())) {
                            return;
                        }
                        if key == KeyEvent::Char('q') {
                            return;
                        }
                    }
                    _ => {}
                }
            }
        });
    }
    {
        let tx = tx.clone();
        thread::spawn(move || {
            let tx = tx.clone();
            loop {
                tx.send(Event::Tick).unwrap();
                thread::sleep(Duration::from_millis(cli.tick_rate));
            }
        });
    }

    let mut app = App::new("Crossterm Demo");

    terminal.clear()?;

    loop {
        ui::draw(&mut terminal, &app)?;
        match rx.recv()? {
            Event::Input(event) => match event {
                KeyEvent::Char(c) => app.on_key(c),
                KeyEvent::Left => app.on_left(),
                KeyEvent::Up => app.on_up(),
                KeyEvent::Right => app.on_right(),
                KeyEvent::Down => app.on_down(),
                _ => {}
            },
            Event::Tick => {
                app.on_tick();
            }
        }
        if app.should_quit {
            break;
        }
    }

    Ok(())
}