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//! 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 --package tour --target wasm32-unknown-unknown //! wasm-bindgen ../target/wasm32-unknown-unknown/debug/tour.wasm --out-dir tour --web //! ``` //! //! Then, we need to create an `.html` file to load our application: //! //! ```html //! <!DOCTYPE html> //! <html> //! <head> //! <meta http-equiv="Content-type" content="text/html; charset=utf-8"/> //! <meta name="viewport" content="width=device-width, initial-scale=1"> //! <title>Tour - Iced</title> //! </head> //! <body> //! <script type="module"> //! import init from "./tour/tour.js"; //! //! init('./tour/tour_bg.wasm'); //! </script> //! </body> //! </html> //! ``` //! //! 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/tree/0.1/examples/tour #![deny(missing_docs)] #![deny(missing_debug_implementations)] #![deny(unused_results)] #![forbid(unsafe_code)] #![forbid(rust_2018_idioms)] use dodrio::bumpalo; use std::{cell::RefCell, rc::Rc}; mod bus; mod element; mod hasher; pub mod css; pub mod subscription; pub mod widget; pub use bus::Bus; pub use css::Css; pub use dodrio; pub use element::Element; pub use hasher::Hasher; pub use iced_core::{ keyboard, mouse, Align, Background, Color, Font, HorizontalAlignment, Length, Point, Rectangle, Size, Vector, VerticalAlignment, }; pub use iced_futures::{executor, futures, Command}; pub use subscription::Subscription; #[doc(no_inline)] pub use widget::*; #[doc(no_inline)] pub use executor::Executor; /// 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 `<title>` 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 [`Executor`] that will run commands and subscriptions. /// /// The [`executor::WasmBindgen`] can be a good choice for the Web. /// /// [`Executor`]: trait.Executor.html /// [`executor::Default`]: executor/struct.Default.html type Executor: Executor; /// The type of __messages__ your [`Application`] will produce. /// /// [`Application`]: trait.Application.html type Message: Send; /// The data needed to initialize your [`Application`]. /// /// [`Application`]: trait.Application.html type Flags; /// Initializes the [`Application`]. /// /// Here is where you should return the initial state of your app. /// /// Additionally, you can return a [`Command`](struct.Command.html) if you /// need to perform some async action in the background on startup. This is /// useful if you want to load state from a file, perform an initial HTTP /// request, etc. /// /// [`Application`]: trait.Application.html fn new(flags: Self::Flags) -> (Self, Command<Self::Message>) where Self: Sized; /// Returns the current title of the [`Application`]. /// /// This title can be dynamic! The runtime will automatically update the /// title of your application when necessary. /// /// [`Application`]: trait.Application.html fn title(&self) -> String; /// 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) -> Command<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>; /// Returns the event [`Subscription`] for the current state of the /// application. /// /// A [`Subscription`] will be kept alive as long as you keep returning it, /// and the __messages__ produced will be handled by /// [`update`](#tymethod.update). /// /// By default, this method returns an empty [`Subscription`]. /// /// [`Subscription`]: struct.Subscription.html fn subscription(&self) -> Subscription<Self::Message> { Subscription::none() } /// Runs the [`Application`]. /// /// [`Application`]: trait.Application.html fn run(flags: Self::Flags) where Self: 'static + Sized, { use futures::stream::StreamExt; let window = web_sys::window().unwrap(); let document = window.document().unwrap(); let body = document.body().unwrap(); let (sender, receiver) = iced_futures::futures::channel::mpsc::unbounded(); let mut runtime = iced_futures::Runtime::new( Self::Executor::new().expect("Create executor"), sender.clone(), ); let (app, command) = runtime.enter(|| Self::new(flags)); let mut title = app.title(); document.set_title(&title); runtime.spawn(command); let application = Rc::new(RefCell::new(app)); let instance = Instance { application: application.clone(), bus: Bus::new(sender), }; let vdom = dodrio::Vdom::new(&body, instance); let event_loop = receiver.for_each(move |message| { let (command, subscription) = runtime.enter(|| { let command = application.borrow_mut().update(message); let subscription = application.borrow().subscription(); (command, subscription) }); let new_title = application.borrow().title(); runtime.spawn(command); runtime.track(subscription); if title != new_title { document.set_title(&new_title); title = new_title; } vdom.weak().schedule_render(); futures::future::ready(()) }); wasm_bindgen_futures::spawn_local(event_loop); } } struct Instance<A: Application> { application: Rc<RefCell<A>>, bus: Bus<A::Message>, } impl<'a, A> dodrio::Render<'a> for Instance<A> where A: Application, { fn render( &self, context: &mut dodrio::RenderContext<'a>, ) -> dodrio::Node<'a> { use dodrio::builder::*; let mut ui = self.application.borrow_mut(); let element = ui.view(); let mut css = Css::new(); let node = element.widget.node(context.bump, &self.bus, &mut css); div(context.bump) .attr("style", "width: 100%; height: 100%") .children(vec![css.node(context.bump), node]) .finish() } }