#![deny(clippy::all)]
#![warn(clippy::pedantic, clippy::nursery)]
use std::error::Error;
use std::io;
use crossterm::event::{self, Event, KeyCode};
use crossterm::terminal::{disable_raw_mode, enable_raw_mode};
use crossterm::terminal::{EnterAlternateScreen, LeaveAlternateScreen};
use ratatui::backend::{Backend, CrosstermBackend};
use ratatui::layout::Alignment;
use ratatui::text::Line;
use ratatui::widgets::{Block, Borders, Paragraph};
use ratatui::{Frame, Terminal};
type Result<T> = std::result::Result<T, Box<dyn Error>>;
#[derive(Default)]
struct App {
hook_enabled: bool,
}
impl App {
fn chain_hook(&mut self) {
let original_hook = std::panic::take_hook();
std::panic::set_hook(Box::new(move |panic| {
reset_terminal().unwrap();
original_hook(panic);
}));
self.hook_enabled = true;
}
}
fn main() -> Result<()> {
let mut terminal = init_terminal()?;
let mut app = App::default();
let res = run_tui(&mut terminal, &mut app);
reset_terminal()?;
if let Err(err) = res {
println!("{err:?}");
}
Ok(())
}
fn init_terminal() -> Result<Terminal<CrosstermBackend<io::Stdout>>> {
crossterm::execute!(io::stdout(), EnterAlternateScreen)?;
enable_raw_mode()?;
let backend = CrosstermBackend::new(io::stdout());
let mut terminal = Terminal::new(backend)?;
terminal.hide_cursor()?;
Ok(terminal)
}
fn reset_terminal() -> Result<()> {
disable_raw_mode()?;
crossterm::execute!(io::stdout(), LeaveAlternateScreen)?;
Ok(())
}
fn run_tui<B: Backend>(terminal: &mut Terminal<B>, app: &mut App) -> io::Result<()> {
loop {
terminal.draw(|f| ui(f, app))?;
if let Event::Key(key) = event::read()? {
match key.code {
KeyCode::Char('p') => {
panic!("intentional demo panic");
}
KeyCode::Char('e') => {
app.chain_hook();
}
_ => {
return Ok(());
}
}
}
}
}
fn ui<B: Backend>(f: &mut Frame<B>, app: &App) {
let text = vec![
if app.hook_enabled {
Line::from("HOOK IS CURRENTLY **ENABLED**")
} else {
Line::from("HOOK IS CURRENTLY **DISABLED**")
},
Line::from(""),
Line::from("press `p` to panic"),
Line::from("press `e` to enable the terminal-resetting panic hook"),
Line::from("press any other key to quit without panic"),
Line::from(""),
Line::from("when you panic without the chained hook,"),
Line::from("you will likely have to reset your terminal afterwards"),
Line::from("with the `reset` command"),
Line::from(""),
Line::from("with the chained panic hook enabled,"),
Line::from("you should see the panic report as you would without ratatui"),
Line::from(""),
Line::from("try first without the panic handler to see the difference"),
];
let b = Block::default()
.title("Panic Handler Demo")
.borders(Borders::ALL);
let p = Paragraph::new(text).block(b).alignment(Alignment::Center);
f.render_widget(p, f.size());
}