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
..
2025-06-03 14:55:23 +03:00

Input Form example

This example demonstrates how to handle input across several form fields (2 strings and an number). It uses an enum to track the focused field, and sends keyboard events to one which is current.

Run this example with:

cargo run -p input-form

This example does not handle things like cursor movement within the line (just keys and backspace). Most apps would benefit from using the following crates for text input rather than directly using strings:

Some more ideas for handling focus can be found in: