ratatui/examples/user_input.rs
2019-01-13 14:35:51 +00:00

113 lines
3.3 KiB
Rust

/// A simple example demonstrating how to handle user input. This is
/// a bit out of the scope of the library as it does not provide any
/// input handling out of the box. However, it may helps some to get
/// started.
///
/// This is a very simple example:
/// * A input box always focused. Every character you type is registered
/// here
/// * Pressing Backspace erases a character
/// * Pressing Enter pushes the current input in the history of previous
/// messages
#[allow(dead_code)]
mod util;
use std::io::{self, Write};
use termion::cursor::Goto;
use termion::event::Key;
use termion::input::MouseTerminal;
use termion::raw::IntoRawMode;
use termion::screen::AlternateScreen;
use tui::backend::TermionBackend;
use tui::layout::{Constraint, Direction, Layout};
use tui::style::{Color, Style};
use tui::widgets::{Block, Borders, List, Paragraph, Text, Widget};
use tui::Terminal;
use unicode_width::UnicodeWidthStr;
use crate::util::event::{Event, Events};
/// App holds the state of the application
struct App {
/// Current value of the input box
input: String,
/// History of recorded messages
messages: Vec<String>,
}
impl Default for App {
fn default() -> App {
App {
input: String::new(),
messages: Vec::new(),
}
}
}
fn main() -> Result<(), failure::Error> {
// Terminal initialization
let stdout = io::stdout().into_raw_mode()?;
let stdout = MouseTerminal::from(stdout);
let stdout = AlternateScreen::from(stdout);
let backend = TermionBackend::new(stdout);
let mut terminal = Terminal::new(backend)?;
// Setup event handlers
let events = Events::new();
// Create default app state
let mut app = App::default();
loop {
// Draw UI
terminal.draw(|mut f| {
let chunks = Layout::default()
.direction(Direction::Vertical)
.margin(2)
.constraints([Constraint::Length(3), Constraint::Min(1)].as_ref())
.split(f.size());
Paragraph::new([Text::raw(&app.input)].iter())
.style(Style::default().fg(Color::Yellow))
.block(Block::default().borders(Borders::ALL).title("Input"))
.render(&mut f, chunks[0]);
let messages = app
.messages
.iter()
.enumerate()
.map(|(i, m)| Text::raw(format!("{}: {}", i, m)));
List::new(messages)
.block(Block::default().borders(Borders::ALL).title("Messages"))
.render(&mut f, chunks[1]);
})?;
// Put the cursor back inside the input box
write!(
terminal.backend_mut(),
"{}",
Goto(4 + app.input.width() as u16, 4)
)?;
// Handle input
match events.next()? {
Event::Input(input) => match input {
Key::Char('q') => {
break;
}
Key::Char('\n') => {
app.messages.push(app.input.drain(..).collect());
}
Key::Char(c) => {
app.input.push(c);
}
Key::Backspace => {
app.input.pop();
}
_ => {}
},
_ => {}
}
}
Ok(())
}