//! A web runtime for Iced, targetting the DOM.
//!
//! 
//!
//! `iced_web` takes [`iced_core`] and builds a WebAssembly runtime on top. It
//! achieves this by introducing a `Widget` trait that can be used to produce
//! VDOM nodes.
//!
//! The crate is currently a __very experimental__, simple abstraction layer
//! over [`dodrio`].
//!
//! [`iced_core`]: https://github.com/hecrj/iced/tree/master/core
//! [`dodrio`]: https://github.com/fitzgen/dodrio
//!
//! # Usage
//! The current build process is a bit involved, as [`wasm-pack`] does not
//! currently [support building binary crates](https://github.com/rustwasm/wasm-pack/issues/734).
//!
//! Therefore, we instead build using the `wasm32-unknown-unknown` target and
//! use the [`wasm-bindgen`] CLI to generate appropriate bindings.
//!
//! For instance, let's say we want to build the [`tour` example]:
//!
//! ```bash
//! cd examples
//! cargo build --example tour --target wasm32-unknown-unknown
//! wasm-bindgen ../target/wasm32-unknown-unknown/debug/examples/tour.wasm --out-dir tour --web
//! ```
//!
//! Then, we need to create an `.html` file to load our application:
//!
//! ```html
//!
//!
//!
//!
//! Tour - Iced
//!
//!
//!
//!
//!
//! ```
//!
//! Finally, we serve it using an HTTP server and access it with our browser.
//!
//! [`wasm-pack`]: https://github.com/rustwasm/wasm-pack
//! [`wasm-bindgen`]: https://github.com/rustwasm/wasm-bindgen
//! [`tour` example]: https://github.com/hecrj/iced/blob/master/examples/tour.rs
#![deny(missing_docs)]
#![deny(missing_debug_implementations)]
#![deny(unused_results)]
#![deny(unsafe_code)]
#![deny(rust_2018_idioms)]
use dodrio::bumpalo;
use std::cell::RefCell;
mod bus;
mod element;
pub mod widget;
pub use bus::Bus;
pub use dodrio;
pub use element::Element;
pub use iced_core::{
Align, Background, Color, Font, HorizontalAlignment, Length,
VerticalAlignment,
};
pub use widget::*;
/// An interactive web application.
///
/// This trait is the main entrypoint of Iced. Once implemented, you can run
/// your GUI application by simply calling [`run`](#method.run). It will take
/// control of the `` and the `<body>` of the document.
///
/// An [`Application`](trait.Application.html) can execute asynchronous actions
/// by returning a [`Command`](struct.Command.html) in some of its methods.
pub trait Application {
/// The type of __messages__ your [`Application`] will produce.
///
/// [`Application`]: trait.Application.html
type Message;
/// Handles a __message__ and updates the state of the [`Application`].
///
/// This is where you define your __update logic__. All the __messages__,
/// produced by either user interactions or commands, will be handled by
/// this method.
///
/// Any [`Command`] returned will be executed immediately in the background.
///
/// [`Application`]: trait.Application.html
/// [`Command`]: struct.Command.html
fn update(&mut self, message: Self::Message);
/// Returns the widgets to display in the [`Application`].
///
/// These widgets can produce __messages__ based on user interaction.
///
/// [`Application`]: trait.Application.html
fn view(&mut self) -> Element<'_, Self::Message>;
/// Runs the [`Application`].
///
/// [`Application`]: trait.Application.html
fn run(self)
where
Self: 'static + Sized,
{
let app = Instance::new(self);
let window = web_sys::window().unwrap();
let document = window.document().unwrap();
let body = document.body().unwrap();
let vdom = dodrio::Vdom::new(&body, app);
vdom.forget();
}
}
struct Instance<Message> {
ui: RefCell<Box<dyn Application<Message = Message>>>,
}
impl<Message> Instance<Message> {
fn new(ui: impl Application<Message = Message> + 'static) -> Self {
Self {
ui: RefCell::new(Box::new(ui)),
}
}
fn update(&mut self, message: Message) {
self.ui.borrow_mut().update(message);
}
}
impl<Message> dodrio::Render for Instance<Message>
where
Message: 'static,
{
fn render<'a, 'bump>(
&'a self,
bump: &'bump bumpalo::Bump,
) -> dodrio::Node<'bump>
where
'a: 'bump,
{
let mut ui = self.ui.borrow_mut();
let element = ui.view();
element.widget.node(bump, &Bus::new())
}
}