Trait iced::Sandbox

source ·

pub trait Sandbox {
    type Message: Debug + Send;

    // Required methods
    fn new() -> Self;
    fn title(&self) -> String;
    fn update(&mut self, message: Self::Message);
    fn view(&self) -> Element<'_, Self::Message>;

    // Provided methods
    fn theme(&self) -> Theme { ... }
    fn style(&self) -> Application { ... }
    fn scale_factor(&self) -> f64 { ... }
    fn run(settings: Settings<()>) -> Result<(), Error>
       where Self: 'static + Sized { ... }
}

Expand description

A sandboxed Application.

If you are a just getting started with the library, this trait offers a simpler interface than Application.

Unlike an Application, a Sandbox cannot run any asynchronous actions or be initialized with some external flags. However, both traits are very similar and upgrading from a Sandbox is very straightforward.

Therefore, it is recommended to always start by implementing this trait and upgrade only once necessary.

§Examples

The repository has a bunch of examples that use the Sandbox trait:

bezier_tool, a Paint-like tool for drawing Bézier curves using the Canvas widget.
counter, the classic counter example explained in the overview.
custom_widget, a demonstration of how to build a custom widget that draws a circle.
geometry, a custom widget showcasing how to draw geometry with the Mesh2D primitive in iced_wgpu.
pane_grid, a grid of panes that can be split, resized, and reorganized.
progress_bar, a simple progress bar that can be filled by using a slider.
styling, an example showcasing custom styling with a light and dark theme.
svg, an application that renders the Ghostscript Tiger by leveraging the Svg widget.
tour, a simple UI tour that can run both on native platforms and the web!

§A simple “Hello, world!”

If you just want to get started, here is a simple Sandbox that says “Hello, world!”:

use iced::{Element, Sandbox, Settings};

pub fn main() -> iced::Result {
    Hello::run(Settings::default())
}

struct Hello;

impl Sandbox for Hello {
    type Message = ();

    fn new() -> Hello {
        Hello
    }

    fn title(&self) -> String {
        String::from("A cool application")
    }

    fn update(&mut self, _message: Self::Message) {
        // This application has no interactions
    }

    fn view(&self) -> Element<Self::Message> {
        "Hello, world!".into()
    }
}