frus-layout

frus's layout engine: it turns a tree of styled nodes into positioned rectangles.

Layer: Foundations. Flexbox comes from taffy, kept behind frus's own types so it can be replaced without breaking the API. It does not know what a widget is. See ARCHITECTURE.md.

What you reach for

• Layout: the node tree. Add leaves and containers, compute it, read the rects back.
• Style, with Dimension, FlexDirection, Justify and Align: what a node asks for.
• Overflowing: what Layout::overflows reports when children do not fit their parent.

Example

use frus_layout::{Dimension, FlexDirection, Layout, Size, Style};

let fixed = |width| Style {
    width: Dimension::Length(width),
    height: Dimension::Length(20.0),
    ..Style::default()
};

let mut layout: Layout<'_, &str> = Layout::new();
let a = layout.leaf(fixed(80.0), "a");
let b = layout.leaf(fixed(80.0), "b");
let row = layout.container(
    Style { flex_direction: FlexDirection::Row, gap: 10.0, ..Style::default() },
    &[a, b],
);
layout.compute(row, Size::new(400.0, 100.0));

let rects = layout.absolute_rects(row);
let (b_rect, _) = rects.iter().find(|(_, data)| *data == Some(&"b")).unwrap();
assert_eq!(b_rect.x, 90.0);

Part of frus

Widgets build their layout through this crate; an application describes layout with widgets instead. See the workspace README. Licensed under MIT or Apache-2.0.