# Buoyant

[](https://crates.io/crates/buoyant)
[](https://docs.rs/buoyant/)
Buoyant is a library for writing and rendering SwiftUI-like views in Rust,
primarily intended for use on `no_std` memory-constrained embedded systems.
Get started with the [Book](https://riley-williams.github.io/buoyant/).
## Available render targets
- `DrawTarget`: `embedded-graphics` displays.
- `TextBuffer`: A basic fixed-size `char` buffer. Does not respect graphemes.
This is primarily useful for testing and debugging.
- `CrossTerm`: Renders colored character-pixels to a terminal using
the `crossterm` crate.
## Example
Here's what an animated toggle button component could look like, implemented with Buoyant:

```rust
fn toggle_button(is_on: bool) -> impl EmbeddedGraphicsView<Rgb565> {
let alignment = if is_on {
HorizontalAlignment::Trailing
} else {
HorizontalAlignment::Leading
};
let color = if is_on { Rgb565::GREEN } else { Rgb565::RED };
ZStack::new((
Capsule.foreground_color(color),
Circle
.foreground_color(Rgb565::WHITE)
.padding(Edges::All, 2),
))
.with_horizontal_alignment(alignment)
.frame_sized(50, 25)
.animated(Animation::ease_in_out(Duration::from_millis(500)), is_on)
.geometry_group()
}
```
## Feature progress
### Layout and Rendering
Static layout and animation between layouts are relatively feature-complete, aside from
transitions. You should be able to construct most desired layouts and animations.
- [x] Stacks of heterogeneous views (VStack, HStack, ZStack)
- [x] Stacks of homogeneous views (ForEach) - partial, vertical only
- [x] Common SwiftUI primitives (Spacer, Divider)
- [x] Conditional views, with match variable binding
- [x] Monospaced Text (whitespace-based line breaking)
- [x] Images (fixed size)
- [x] Interruptible Animations + Curves
- [x] Common embedded-graphics shape primitives
- [ ] Simulated alpha and antialiasing
- [ ] Transitions
- [ ] Shape stroke/fill
- [ ] Shape styles (e.g. gradients)
- [ ] Canvas for arbitrary path/shape/raster drawing
### Interactivity
No interactivity or state management currently exists, but it is the next major
planned feature.
- [ ] State management
- [ ] Click/tap routing
- [ ] Focus management + keyboard input (Text input view)
## Who should use this?
This project could be used in production by the brave, but is probably better suited
for hobby projects at this point. It's significantly better than dealing with raw
embedded-graphics. If you're familiar with SwiftUI, you should feel especially at home.
## License
Licensed under either of
- Apache License, Version 2.0
([LICENSE-APACHE](LICENSE-APACHE) or <http://www.apache.org/licenses/LICENSE-2.0>)
- MIT license
([LICENSE-MIT](LICENSE-MIT) or <http://opensource.org/licenses/MIT>)
at your option.
## Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.