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Ratatui

Ratatui Website · API Docs · Examples · Changelog · Breaking Changes
Contributing · Report a bug · Request a Feature · Create a Pull Request

Ratatui

Ratatui is a crate for cooking up terminal user interfaces in Rust. It is a lightweight library that provides a set of widgets and utilities to build complex Rust TUIs. Ratatui was forked from the tui-rs crate in 2023 in order to continue its development.

Installation

Add ratatui as a dependency to your cargo.toml:

cargo add ratatui

Ratatui uses Crossterm by default as it works on most platforms. See the Installation section of the Ratatui Website for more details on how to use other backends (Termion / Termwiz).

Introduction

Ratatui is based on the principle of immediate rendering with intermediate buffers. This means that for each frame, your app must render all widgets that are supposed to be part of the UI. This is in contrast to the retained mode style of rendering where widgets are updated and then automatically redrawn on the next frame. See the Rendering section of the Ratatui Website for more info.

You can also watch the FOSDEM 2024 talk about Ratatui which gives a brief introduction to terminal user interfaces and showcases the features of Ratatui, along with a hello world demo.

Quickstart

The following example demonstrates the minimal amount of code necessary to setup a terminal and render "Hello World!". The full code for this example which contains a little more detail is in the Examples directory. For more guidance on different ways to structure your application see the Application Patterns and Hello World tutorial sections in the Ratatui Website and the various Examples. There are also several starter templates available in the templates repository.

Every application built with ratatui needs to implement the following steps:

Initialize the terminal
A main loop to:
- Handle input events
- Draw the UI
Restore the terminal state

The library contains a [prelude] module that re-exports the most commonly used traits and types for convenience. Most examples in the documentation will use this instead of showing the full path of each type.

Initialize and restore the terminal

The [Terminal] type is the main entry point for any Ratatui application. It is a light abstraction over a choice of Backend implementations that provides functionality to draw each frame, clear the screen, hide the cursor, etc. It is parametrized over any type that implements the Backend trait which has implementations for Crossterm, Termion and Termwiz.

Most applications should enter the Alternate Screen when starting and leave it when exiting and also enable raw mode to disable line buffering and enable reading key events. See the backend module and the Backends section of the Ratatui Website for more info.

Drawing the UI

The drawing logic is delegated to a closure that takes a Frame instance as argument. The Frame provides the size of the area to draw to and allows the app to render any Widget using the provided render_widget method. After this closure returns, a diff is performed and only the changes are drawn to the terminal. See the Widgets section of the Ratatui Website for more info.

Handling events

Ratatui does not include any input handling. Instead event handling can be implemented by calling backend library methods directly. See the Handling Events section of the Ratatui Website for more info. For example, if you are using Crossterm, you can use the crossterm::event module to handle events.

Example

use std::io::{self, stdout};

use ratatui::{
    backend::CrosstermBackend,
    crossterm::{
        event::{self, Event, KeyCode},
        terminal::{
            disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
        },
        ExecutableCommand,
    },
    widgets::{Block, Paragraph},
    Frame, Terminal,
};

fn main() -> io::Result<()> {
    enable_raw_mode()?;
    stdout().execute(EnterAlternateScreen)?;
    let mut terminal = Terminal::new(CrosstermBackend::new(stdout()))?;

    let mut should_quit = false;
    while !should_quit {
        terminal.draw(ui)?;
        should_quit = handle_events()?;
    }

    disable_raw_mode()?;
    stdout().execute(LeaveAlternateScreen)?;
    Ok(())
}

fn handle_events() -> io::Result<bool> {
    if event::poll(std::time::Duration::from_millis(50))? {
        if let Event::Key(key) = event::read()? {
            if key.kind == event::KeyEventKind::Press && key.code == KeyCode::Char('q') {
                return Ok(true);
            }
        }
    }
    Ok(false)
}

fn ui(frame: &mut Frame) {
    frame.render_widget(
        Paragraph::new("Hello World!").block(Block::bordered().title("Greeting")),
        frame.area(),
    );
}

Running this example produces the following output:

Layout

The library comes with a basic yet useful layout management object called Layout which allows you to split the available space into multiple areas and then render widgets in each area. This lets you describe a responsive terminal UI by nesting layouts. See the Layout section of the Ratatui Website for more info.

use ratatui::{
    layout::{Constraint, Layout},
    widgets::Block,
    Frame,
};

fn ui(frame: &mut Frame) {
    let [title_area, main_area, status_area] = Layout::vertical([
        Constraint::Length(1),
        Constraint::Min(0),
        Constraint::Length(1),
    ])
    .areas(frame.area());
    let [left_area, right_area] =
        Layout::horizontal([Constraint::Percentage(50), Constraint::Percentage(50)])
            .areas(main_area);

    frame.render_widget(Block::bordered().title("Title Bar"), title_area);
    frame.render_widget(Block::bordered().title("Status Bar"), status_area);
    frame.render_widget(Block::bordered().title("Left"), left_area);
    frame.render_widget(Block::bordered().title("Right"), right_area);
}

Running this example produces the following output:

Text and styling

The Text, Line and Span types are the building blocks of the library and are used in many places. Text is a list of Lines and a Line is a list of Spans. A Span is a string with a specific style.

The style module provides types that represent the various styling options. The most important one is Style which represents the foreground and background colors and the text attributes of a Span. The style module also provides a Stylize trait that allows short-hand syntax to apply a style to widgets and text. See the Styling Text section of the Ratatui Website for more info.

use ratatui::{
    layout::{Constraint, Layout},
    style::{Color, Modifier, Style, Stylize},
    text::{Line, Span},
    widgets::{Block, Paragraph},
    Frame,
};

fn ui(frame: &mut Frame) {
    let areas = Layout::vertical([Constraint::Length(1); 4]).split(frame.area());

    let line = Line::from(vec![
        Span::raw("Hello "),
        Span::styled(
            "World",
            Style::new()
                .fg(Color::Green)
                .bg(Color::White)
                .add_modifier(Modifier::BOLD),
        ),
        "!".red().on_light_yellow().italic(),
    ]);
    frame.render_widget(line, areas[0]);

    // using the short-hand syntax and implicit conversions
    let paragraph = Paragraph::new("Hello World!".red().on_white().bold());
    frame.render_widget(paragraph, areas[1]);

    // style the whole widget instead of just the text
    let paragraph = Paragraph::new("Hello World!").style(Style::new().red().on_white());
    frame.render_widget(paragraph, areas[2]);

    // use the simpler short-hand syntax
    let paragraph = Paragraph::new("Hello World!").blue().on_yellow();
    frame.render_widget(paragraph, areas[3]);
}

Running this example produces the following output:

Status of this fork

In response to the original maintainer Florian Dehau's issue regarding the future of tui-rs, several members of the community forked the project and created this crate. We look forward to continuing the work started by Florian 🚀

In order to organize ourselves, we currently use a Discord server, feel free to join and come chat! There is also a Matrix bridge available at #ratatui:matrix.org.

While we do utilize Discord for coordinating, it's not essential for contributing. We have recently launched the Ratatui Forum, and our primary open-source workflow is centered around GitHub. For bugs and features, we rely on GitHub. Please Report a bug, Request a Feature or Create a Pull Request.

Please make sure you read the updated contributing guidelines, especially if you are interested in working on a PR or issue opened in the previous repository.

Widgets

Built in

The library comes with the following widgets:

BarChart
Block
Calendar
Canvas which allows rendering points, lines, shapes and a world map
Chart
Clear
Gauge
List
Paragraph
Scrollbar
Sparkline
Table
Tabs

Each widget has an associated example which can be found in the Examples folder. Run each example with cargo (e.g. to run the gauge example cargo run --example gauge), and quit by pressing q.

You can also run all examples by running cargo make run-examples (requires cargo-make that can be installed with cargo install cargo-make).

Third-party libraries, bootstrapping templates and widgets

ansi-to-tui — Convert ansi colored text to ratatui::text::Text
color-to-tui — Parse hex colors to ratatui::style::Color
templates — Starter templates for bootstrapping a Rust TUI application with Ratatui & crossterm
tui-builder — Batteries-included MVC framework for Tui-rs + Crossterm apps
tui-clap — Use clap-rs together with Tui-rs
tui-log — Example of how to use logging with Tui-rs
tui-logger — Logger and Widget for Tui-rs
tui-realm — Tui-rs framework to build stateful applications with a React/Elm inspired approach
tui-realm-treeview — Treeview component for Tui-realm
tui-rs-tree-widgets — Widget for tree data structures.
tui-windows — Tui-rs abstraction to handle multiple windows and their rendering
tui-textarea — Simple yet powerful multi-line text editor widget supporting several key shortcuts, undo/redo, text search, etc.
tui-input — TUI input library supporting multiple backends and tui-rs.
tui-term — A pseudoterminal widget library that enables the rendering of terminal applications as ratatui widgets.

Apps

Check out awesome-ratatui for a curated list of awesome apps/libraries built with ratatui!

Alternatives

You might want to checkout Cursive for an alternative solution to build text user interfaces in Rust.

Acknowledgments

Special thanks to Pavel Fomchenkov for his work in designing an awesome logo for the ratatui project and ratatui organization.

License

MIT

ethan75/ratatui

Ratatui

Installation

Introduction

Other documentation

Quickstart

Initialize and restore the terminal

Drawing the UI

Handling events

Example

Layout

Text and styling

Status of this fork

Widgets

Built in

Third-party libraries, bootstrapping templates and widgets

Apps

Alternatives

Acknowledgments

License