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https://github.com/ratatui-org/ratatui
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ed51c4b342
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>
72 lines
3 KiB
Rust
72 lines
3 KiB
Rust
//! # [Ratatui] Hello World example
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//!
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//! The latest version of this example is available in the [examples] folder in the repository.
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//!
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//! Please note that the examples are designed to be run against the `main` branch of the Github
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//! repository. This means that you may not be able to compile with the latest release version on
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//! crates.io, or the one that you have installed locally.
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//!
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//! See the [examples readme] for more information on finding examples that match the version of the
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//! library you are using.
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//!
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//! [Ratatui]: https://github.com/ratatui/ratatui
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//! [examples]: https://github.com/ratatui/ratatui/blob/main/examples
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//! [examples readme]: https://github.com/ratatui/ratatui/blob/main/examples/README.md
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use std::time::Duration;
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use color_eyre::{eyre::Context, Result};
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use ratatui::{
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crossterm::event::{self, Event, KeyCode},
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widgets::Paragraph,
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DefaultTerminal, Frame,
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};
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/// This is a bare minimum example. There are many approaches to running an application loop, so
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/// this is not meant to be prescriptive. It is only meant to demonstrate the basic setup and
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/// teardown of a terminal application.
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///
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/// This example does not handle events or update the application state. It just draws a greeting
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/// and exits when the user presses 'q'.
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fn main() -> Result<()> {
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color_eyre::install()?; // augment errors / panics with easy to read messages
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let terminal = ratatui::init();
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let app_result = run(terminal).context("app loop failed");
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ratatui::restore();
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app_result
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}
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/// Run the application loop. This is where you would handle events and update the application
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/// state. This example exits when the user presses 'q'. Other styles of application loops are
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/// possible, for example, you could have multiple application states and switch between them based
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/// on events, or you could have a single application state and update it based on events.
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fn run(mut terminal: DefaultTerminal) -> Result<()> {
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loop {
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terminal.draw(draw)?;
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if should_quit()? {
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break;
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}
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}
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Ok(())
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}
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/// Render the application. This is where you would draw the application UI. This example draws a
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/// greeting.
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fn draw(frame: &mut Frame) {
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let greeting = Paragraph::new("Hello World! (press 'q' to quit)");
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frame.render_widget(greeting, frame.area());
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}
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/// Check if the user has pressed 'q'. This is where you would handle events. This example just
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/// checks if the user has pressed 'q' and returns true if they have. It does not handle any other
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/// events. There is a 250ms timeout on the event poll to ensure that the terminal is rendered at
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/// least once every 250ms. This allows you to do other work in the application loop, such as
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/// updating the application state, without blocking the event loop for too long.
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fn should_quit() -> Result<bool> {
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if event::poll(Duration::from_millis(250)).context("event poll failed")? {
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if let Event::Key(key) = event::read().context("event read failed")? {
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return Ok(KeyCode::Char('q') == key.code);
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}
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}
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Ok(false)
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}
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