buoyant 0.7.0

SwiftUI-like UIs in Rust for embedded devices
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82

# Manual View Lifecycle

Taking the simple Hello World example, the `AsDrawable` trait usage can be replaced
with a manual view lifecycle.

```rust,no_run
# extern crate buoyant;
# extern crate embedded_graphics;
# extern crate embedded_graphics_simulator;
use buoyant::{
    environment::DefaultEnvironment,
    render::Render as _,
    render_target::EmbeddedGraphicsRenderTarget,
    view::prelude::*,
};
use embedded_graphics::{mono_font::ascii::FONT_10X20, pixelcolor::Rgb888, prelude::*};
use embedded_graphics_simulator::{OutputSettings, SimulatorDisplay, Window};

const BACKGROUND_COLOR: Rgb888 = Rgb888::BLACK;
const DEFAULT_COLOR: Rgb888 = Rgb888::WHITE;

fn main() {
    let size = Size::new(480, 320);
    let mut window = Window::new("Hello World", &OutputSettings::default());
    let mut display: SimulatorDisplay<Rgb888> = SimulatorDisplay::new(size);
    let mut target = EmbeddedGraphicsRenderTarget::new(&mut display);

    target.display_mut().clear(BACKGROUND_COLOR).unwrap();

    let environment = DefaultEnvironment::default();
    let origin = buoyant::primitives::Point::zero();

    let mut app_data = ();

    let view = hello_view();

    let mut app_state = view.build_state(&mut app_data);
    let layout = view.layout(&size.into(), &environment, &mut app_data, &mut app_state);
    let render_tree = view.render_tree(&layout.sublayouts, origin, &environment, &mut app_data, &mut app_state);

    render_tree.render(&mut target, &DEFAULT_COLOR);

    window.show_static(target.display());
}

fn hello_view() -> impl View<Rgb888, ()> {
    HStack::new((
        Text::new("Hello", &FONT_10X20).foreground_color(Rgb888::GREEN),
        Spacer::default(),
        Text::new("World", &FONT_10X20).foreground_color(Rgb888::YELLOW),
    ))
    .padding(Edges::All, 20)
}
```

## Layout

```rust,ignore
let layout = view.layout(&size.into(), &environment, &mut app_data, &mut app_state);
```

The layout call resolves the sizes of all the views. It is a bug to try to reuse the layout
after mutating the view, and Buoyant may panic if you do so.

## Render Tree

```rust,ignore
let render_tree = view.render_tree(&layout, origin, &environment, &mut app_data, &mut app_state);
```

The render tree is a minimal snapshot of the view. It holds a copy of the resolved positions,
sizes, colors, etc. of all the elements that are actually rendered to the screen.
Relational elements like `Padding`, `Frame`s, alignment, and so on have been stripped.

## Rendering

```rust,ignore
render_tree.render(&mut display, &DEFAULT_COLOR, origin);
```

Here, the snapshot is finally rendered to the display buffer. A default color is passed in
which is used for elements that aren't explicitly colored using `.foreground_color()`.