ratatui/examples/modifiers.rs
Josh McKinney ed51c4b342
feat(terminal): Add ratatui::init() and restore() methods (#1289)
These are simple opinionated methods for creating a terminal that is
useful to use in most apps. The new init method creates a crossterm
backend writing to stdout, enables raw mode, enters the alternate
screen, and sets a panic handler that restores the terminal on panic.

A minimal hello world now looks a bit like:

```rust
use ratatui::{
    crossterm::event::{self, Event},
    text::Text,
    Frame,
};

fn main() {
    let mut terminal = ratatui::init();
    loop {
        terminal
            .draw(|frame: &mut Frame| frame.render_widget(Text::raw("Hello World!"), frame.area()))
            .expect("Failed to draw");
        if matches!(event::read().expect("failed to read event"), Event::Key(_)) {
            break;
        }
    }
    ratatui::restore();
}
```

A type alias `DefaultTerminal` is added to represent this terminal
type and to simplify any cases where applications need to pass this
terminal around. It is equivalent to:
`Terminal<CrosstermBackend<Stdout>>`

We also added `ratatui::try_init()` and `try_restore()`, for situations
where you might want to handle initialization errors yourself instead
of letting the panic handler fire and cleanup. Simple Apps should
prefer the `init` and `restore` functions over these functions.

Corresponding functions to allow passing a `TerminalOptions` with
a `Viewport` (e.g. inline, fixed) are also available
(`init_with_options`,
and `try_init_with_options`).

The existing code to create a backend and terminal will remain and
is not deprecated by this approach. This just provides a simple one
line initialization using the common options.

---------

Co-authored-by: Orhun Parmaksız <orhunparmaksiz@gmail.com>
2024-08-22 15:16:35 +03:00

100 lines
3.5 KiB
Rust

//! # [Ratatui] Modifiers 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
// This example is useful for testing how your terminal emulator handles different modifiers.
// It will render a grid of combinations of foreground and background colors with all
// modifiers applied to them.
use std::{error::Error, iter::once, result};
use itertools::Itertools;
use ratatui::{
crossterm::event::{self, Event, KeyCode, KeyEventKind},
layout::{Constraint, Layout},
style::{Color, Modifier, Style, Stylize},
text::Line,
widgets::Paragraph,
DefaultTerminal, Frame,
};
type Result<T> = result::Result<T, Box<dyn Error>>;
fn main() -> Result<()> {
color_eyre::install()?;
let terminal = ratatui::init();
let app_result = run(terminal);
ratatui::restore();
app_result
}
fn run(mut terminal: DefaultTerminal) -> Result<()> {
loop {
terminal.draw(draw)?;
if let Event::Key(key) = event::read()? {
if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
return Ok(());
}
}
}
}
fn draw(frame: &mut Frame) {
let vertical = Layout::vertical([Constraint::Length(1), Constraint::Min(0)]);
let [text_area, main_area] = vertical.areas(frame.area());
frame.render_widget(
Paragraph::new("Note: not all terminals support all modifiers")
.style(Style::default().fg(Color::Red).add_modifier(Modifier::BOLD)),
text_area,
);
let layout = Layout::vertical([Constraint::Length(1); 50])
.split(main_area)
.iter()
.flat_map(|area| {
Layout::horizontal([Constraint::Percentage(20); 5])
.split(*area)
.to_vec()
})
.collect_vec();
let colors = [
Color::Black,
Color::DarkGray,
Color::Gray,
Color::White,
Color::Red,
];
let all_modifiers = once(Modifier::empty())
.chain(Modifier::all().iter())
.collect_vec();
let mut index = 0;
for bg in &colors {
for fg in &colors {
for modifier in &all_modifiers {
let modifier_name = format!("{modifier:11?}");
let padding = (" ").repeat(12 - modifier_name.len());
let paragraph = Paragraph::new(Line::from(vec![
modifier_name.fg(*fg).bg(*bg).add_modifier(*modifier),
padding.fg(*fg).bg(*bg).add_modifier(*modifier),
// This is a hack to work around a bug in VHS which is used for rendering the
// examples to gifs. The bug is that the background color of a paragraph seems
// to bleed into the next character.
".".black().on_black(),
]));
frame.render_widget(paragraph, layout[index]);
index += 1;
}
}
}
}