Josh McKinney 6dcd53bc6b
feat: add ergonomic methods for layouting Rects (#1909)
This commit introduces new methods for the `Rect` struct that simplify
the process of splitting a `Rect` into sub-rects according to a given
`Layout`. By putting these methods on the `Rect` struct, we make it a
bit more natural that a layout is applied to the `Rect` itself, rather
than passing a `Rect` to the `Layout` struct to be split.

Adds:
- `Rect::layout` and `Rect::try_layout` methods that allow splitting a
  `Rect` into an array of sub-rects according to a given `Layout`.
- `Rect::layout_vec` method that returns a `Vec` of sub-rects.
- `Layout::try_areas` method that returns an array of sub-rects, with
  compile-time checks for the number of constraints. This is added
  mainly for consistency with the new `Rect` methods.

```rust
use ratatui_core::layout::{Layout, Constraint, Rect};
let area = Rect::new(0, 0, 10, 10);
let layout = Layout::vertical([Constraint::Fill(1); 2]);

// Rect::layout() infers the number of constraints at compile time:
let [top, main] = area.layout(&layout);

// Rect::try_layout() and Layout::try_areas() do the same, but return a
// Result:
let [top, main] = area.try_layout(&layout)?;
let [top, main] = layout.try_areas(area)?;

// Rect::layout_vec() returns a Vec of sub-rects:
let areas_vec = area.layout_vec(&layout);

// you can also explicitly specify the number of constraints:
let areas = area.layout::<2>(&layout);
let areas = area.try_layout::<2>(&layout)?;
let areas = layout.try_areas::<2>(area)?;
```
2025-06-28 01:23:34 -07:00

83 lines
3.1 KiB
Rust

//! # [Ratatui] `Tabs` example
//!
//! The latest version of this example is available in the [widget 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
//! [widget examples]: https://github.com/ratatui/ratatui/blob/main/ratatui-widgets/examples
//! [examples readme]: https://github.com/ratatui/ratatui/blob/main/examples/README.md
use color_eyre::Result;
use crossterm::event::{self, KeyCode};
use ratatui::layout::{Alignment, Constraint, Layout, Offset, Rect};
use ratatui::style::{Color, Style, Stylize};
use ratatui::text::{Line, Span};
use ratatui::widgets::{Block, Paragraph, Tabs};
use ratatui::{Frame, symbols};
fn main() -> Result<()> {
color_eyre::install()?;
let mut selection = 0;
ratatui::run(|terminal| {
loop {
terminal.draw(|frame| render(frame, selection))?;
if let Some(key) = event::read()?.as_key_press_event() {
match key.code {
KeyCode::Char('q') | KeyCode::Esc => break Ok(()),
KeyCode::Char('l') | KeyCode::Right => selection = (selection + 1) % 3,
KeyCode::Char('h') | KeyCode::Left => selection = (selection + 2) % 3,
_ => {}
}
}
}
})
}
/// Render the UI with tabs.
fn render(frame: &mut Frame, selected_tab: usize) {
let layout = Layout::vertical([Constraint::Length(1), Constraint::Fill(1)]).spacing(1);
let [top, main] = frame.area().layout(&layout);
let title = Line::from_iter([
Span::from("Tabs Widget").bold(),
Span::from(" (Press 'q' to quit, arrow keys to navigate tabs)"),
]);
frame.render_widget(title.centered(), top);
render_content(frame, main, selected_tab);
render_tabs(frame, main.offset(Offset { x: 1, y: 0 }), selected_tab);
}
/// Render the tabs.
pub fn render_tabs(frame: &mut Frame, area: Rect, selected_tab: usize) {
let tabs = Tabs::new(vec!["Tab1", "Tab2", "Tab3"])
.style(Color::White)
.highlight_style(Style::default().magenta().on_black().bold())
.select(selected_tab)
.divider(symbols::DOT)
.padding(" ", " ");
frame.render_widget(tabs, area);
}
/// Render the tab content.
pub fn render_content(frame: &mut Frame, area: Rect, selected_tab: usize) {
let text = match selected_tab {
0 => "Great terminal interfaces start with a single widget.".into(),
1 => "In the terminal, we don't just render widgets; we create dreams.".into(),
2 => "Render boldly, style with purpose.".bold(),
_ => unreachable!(),
};
let block = Paragraph::new(text)
.alignment(Alignment::Center)
.block(Block::bordered());
frame.render_widget(block, area);
}