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

99 lines
3.8 KiB
Rust

//! # [Ratatui] `Table` 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::Frame;
use ratatui::layout::{Constraint, Layout, Rect};
use ratatui::style::{Color, Style, Stylize};
use ratatui::text::{Line, Span};
use ratatui::widgets::{Row, Table, TableState};
fn main() -> Result<()> {
color_eyre::install()?;
let mut table_state = TableState::default();
table_state.select_first();
table_state.select_first_column();
ratatui::run(|terminal| {
loop {
terminal.draw(|frame| render(frame, &mut table_state))?;
if let Some(key) = event::read()?.as_key_press_event() {
match key.code {
KeyCode::Char('q') | KeyCode::Esc => return Ok(()),
KeyCode::Char('j') | KeyCode::Down => table_state.select_next(),
KeyCode::Char('k') | KeyCode::Up => table_state.select_previous(),
KeyCode::Char('l') | KeyCode::Right => table_state.select_next_column(),
KeyCode::Char('h') | KeyCode::Left => table_state.select_previous_column(),
KeyCode::Char('g') => table_state.select_first(),
KeyCode::Char('G') => table_state.select_last(),
_ => {}
}
}
}
})
}
/// Render the UI with a table.
fn render(frame: &mut Frame, table_state: &mut TableState) {
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("Table Widget").bold(),
Span::from(" (Press 'q' to quit and arrow keys to navigate)"),
]);
frame.render_widget(title.centered(), top);
render_table(frame, main, table_state);
}
/// Render a table with some rows and columns.
pub fn render_table(frame: &mut Frame, area: Rect, table_state: &mut TableState) {
let header = Row::new(["Ingredient", "Quantity", "Macros"])
.style(Style::new().bold())
.bottom_margin(1);
let rows = [
Row::new(["Eggplant", "1 medium", "25 kcal, 6g carbs, 1g protein"]),
Row::new(["Tomato", "2 large", "44 kcal, 10g carbs, 2g protein"]),
Row::new(["Zucchini", "1 medium", "33 kcal, 7g carbs, 2g protein"]),
Row::new(["Bell Pepper", "1 medium", "24 kcal, 6g carbs, 1g protein"]),
Row::new(["Garlic", "2 cloves", "9 kcal, 2g carbs, 0.4g protein"]),
];
let footer = Row::new([
"Ratatouille Recipe",
"",
"135 kcal, 31g carbs, 6.4g protein",
]);
let widths = [
Constraint::Percentage(30),
Constraint::Percentage(20),
Constraint::Percentage(50),
];
let table = Table::new(rows, widths)
.header(header)
.footer(footer.italic())
.column_spacing(1)
.style(Color::White)
.row_highlight_style(Style::new().on_black().bold())
.column_highlight_style(Color::Gray)
.cell_highlight_style(Style::new().reversed().yellow())
.highlight_symbol("🍴 ");
frame.render_stateful_widget(table, area, table_state);
}