ui_layout

A minimal Flexbox-inspired layout engine for Rust GUI development.

This crate provides a small, predictable layout system designed for custom GUI frameworks, editors, and experimental UI engines.

[!NOTE] This crate is under active development; patch releases may be frequent.

Features

• Flex layout (Row / Column)
• flex_grow and flex_basis
• Fixed, percentage, and viewport-relative sizing via Length
• Min / max size constraints (Length-based)
• Margin, padding, and gaps with CSS-like spacing semantics
• Block layout
• Recursive tree-based layout
• Parent-relative positioning
• Row and column gaps (row_gap / column_gap)
• Justify content (justify_content) and align items (align_items)

Non-goals

• Full CSS compatibility
• Inline or text layout
• Absolute / fixed positioning
• Web rendering or HTML/CSS parsing

Design goals

• Simple and explicit layout rules
• Easy to reason about and debug
• Suitable for custom renderers (wgpu, skia, etc.)
• No dependency on web standards or DOM

Example

use layout::*;

LayoutEngine::layout(&mut root, 800.0, 600.0);

For more examples and to understand the behavior of gaps, alignment, and sizing, see the unit tests in the tests/ directory. They provide practical usage patterns and expected layouts.

Status

See CHANGELOG.md for a detailed list of changes.

• Version: 0.8.0
• API is evolving but now includes full Flexbox-like alignment and gaps

Future versions may add:

• flex_shrink
• grid
• Additional flex sizing rules (wrap, fr units, etc.)
• Absolute / fixed positioning

License

MIT