WIP - wasm_bindgen backend for eventloop-2.0

.circleci/config.yml

@@ -32,7 +32,7 @@ jobs:
           paths:
             - target
 
-  wasm-test:
+  emscripten-test:
     working_directory: ~/winit
     docker:
       - image: tomaka/rustc-emscripten
@@ -43,7 +43,22 @@ jobs:
           key: wasm-test-cache-{{ checksum "Cargo.toml" }}
       - run: cargo build --example window --target wasm32-unknown-emscripten
       - save_cache:
+          key: emscripten-test-cache-{{ checksum "Cargo.toml" }}
+          paths:
+            - target
+
+  websys-test:
+    working_directory: ~/winit
+    docker:
+      - image: tomaka/rustc-emscripten
+    steps:
+      - run: apt-get -qq update && apt-get install -y git
+      - checkout
+      - restore_cache:
           key: wasm-test-cache-{{ checksum "Cargo.toml" }}
+      - run: cargo build --example wasm_bindgen --target wasm32-unknown-unknown --features websys
+      - save_cache:
+          key: websys-test-cache-{{ checksum "Cargo.toml" }}
           paths:
             - target
 
@@ -53,4 +68,5 @@ workflows:
     jobs:
       - android-test
       - asmjs-test
-      - wasm-test
+      - emscripten-test
+      - websys-test

Cargo.toml

@@ -13,6 +13,9 @@ categories = ["gui"]
 [package.metadata.docs.rs]
 features = ["serde"]
 
+[features]
+websys = ["wasm-bindgen", "web-sys"]
+
 [dependencies]
 lazy_static = "1"
 libc = "0.2"
@@ -72,3 +75,24 @@ percent-encoding = "1.0"
 
 [target.'cfg(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd", target_os = "windows"))'.dependencies.parking_lot]
 version = "0.8"
+
+[target.'cfg(target_arch = "wasm32")'.dependencies.wasm-bindgen]
+version = "0.2"
+optional = true
+
+[target.'cfg(target_arch = "wasm32")'.dependencies.web-sys]
+version = "0.3.4"
+optional = true
+features = [
+    'Document',
+    'Element',
+    'HtmlElement',
+    'HtmlCanvasElement',
+    'CanvasRenderingContext2d',
+    'MouseEvent',
+    'Node',
+    'Window',
+    'console',
+    'CssStyleDeclaration',
+    'DomRect',
+]

examples/wasm_bindgen.rs

@@ -0,0 +1,74 @@
+extern crate web_sys;
+extern crate wasm_bindgen;
+
+extern crate winit;
+use winit::window::WindowBuilder;
+use winit::event::{Event, WindowEvent};
+use winit::event_loop::{EventLoop, ControlFlow};
+use winit::platform::websys::WebsysWindowExt;
+use winit::platform::websys::WebsysWindowBuilderExt;
+
+use wasm_bindgen::prelude::*;
+use wasm_bindgen::JsCast;
+
+// A macro to provide `println!(..)`-style syntax for `console.log` logging.
+macro_rules! log {
+    ( $( $t:tt )* ) => {
+        web_sys::console::log_1(&format!( $( $t )* ).into());
+    }
+}
+
+// use wee_alloc if it is available
+#[cfg(feature = "wee_alloc")]
+#[global_allocator]
+static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+
+#[wasm_bindgen]
+struct App {}
+
+#[wasm_bindgen]
+impl App {
+    pub fn new() -> App {
+        App{}
+    }
+
+    pub fn run(&self) {
+        // create an event loop
+        let event_loop = EventLoop::new();
+
+        // create a window and associate it with the event loop
+        let window = WindowBuilder::new()
+            .with_title("A fantastic window!")
+            .with_canvas_id("test")
+            .build(&event_loop)
+            .unwrap();
+
+        // do some drawing
+        let canvas = window.get_canvas();
+        let ctx = canvas.get_context("2d").unwrap().unwrap()
+                        .dyn_into::<web_sys::CanvasRenderingContext2d>().unwrap();
+        ctx.begin_path();
+        ctx.arc(95.0, 50.0, 40.0, 0.0, 2.0 * 3.14159).unwrap();
+        ctx.stroke();
+
+        // run forever
+        //
+        // when using wasm_bindgen, this will currently throw a js
+        // exception once all browser event handlers have been installed.
+        event_loop.run(|event, _, control_flow| {
+
+            match event {
+                Event::WindowEvent {
+                    event: WindowEvent::CloseRequested,
+                    ..
+                } => *control_flow = ControlFlow::Exit,
+                _ => *control_flow = ControlFlow::Poll,
+            }
+        });
+    }
+}
+
+pub fn main() {
+    let app = App::new();
+    app.run();
+}

src/lib.rs

@@ -111,6 +111,10 @@ extern crate percent_encoding;
 extern crate smithay_client_toolkit as sctk;
 #[cfg(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd", target_os = "netbsd", target_os = "openbsd"))]
 extern crate calloop;
+#[cfg(all(target_arch = "wasm32", target_os = "unknown", feature = "websys"))]
+extern crate wasm_bindgen;
+#[cfg(all(target_arch = "wasm32", target_os = "unknown", feature = "websys"))]
+extern crate web_sys;
 
 pub mod dpi;
 #[macro_use]

src/platform/mod.rs

@@ -19,5 +19,6 @@ pub mod ios;
 pub mod macos;
 pub mod unix;
 pub mod windows;
+pub mod websys;
 
 pub mod desktop;

src/platform/websys.rs

@@ -0,0 +1,33 @@
+extern crate wasm_bindgen;
+extern crate web_sys;
+
+use platform_impl::window::ElementSelection;
+use window::{Window, WindowBuilder};
+
+pub trait WebsysWindowExt {
+    fn get_canvas<'a>(&'a self) -> &'a web_sys::HtmlCanvasElement;
+}
+
+impl WebsysWindowExt for Window {
+    fn get_canvas<'a>(&'a self) -> &'a web_sys::HtmlCanvasElement {
+        &self.window.canvas
+    }
+}
+
+pub trait WebsysWindowBuilderExt {
+    fn with_canvas_id(self, canvas_id: &str) -> WindowBuilder;
+
+    fn with_container_id(self, container_id: &str) -> WindowBuilder;
+}
+
+impl WebsysWindowBuilderExt for WindowBuilder {
+    fn with_canvas_id(mut self, canvas_id: &str) -> WindowBuilder {
+        self.platform_specific.element = ElementSelection::CanvasId(canvas_id.to_string());
+        self
+    }
+
+    fn with_container_id(mut self, container_id: &str) -> WindowBuilder {
+        self.platform_specific.element = ElementSelection::ContainerId(container_id.to_string());
+        self
+    }
+}

src/platform_impl/mod.rs

@@ -18,9 +18,12 @@ mod platform;
 #[cfg(target_os = "emscripten")]
 #[path="emscripten/mod.rs"]
 mod platform;
+#[cfg(all(target_arch = "wasm32", target_os = "unknown", feature = "websys"))]
+#[path="websys/mod.rs"]
+mod platform;
 
 #[cfg(all(not(target_os = "ios"), not(target_os = "windows"), not(target_os = "linux"),
   not(target_os = "macos"), not(target_os = "android"), not(target_os = "dragonfly"),
   not(target_os = "freebsd"), not(target_os = "netbsd"), not(target_os = "openbsd"),
-  not(target_os = "emscripten")))]
+  not(target_os = "emscripten"), not(all(target_arch = "wasm32", feature="websys"))))]
 compile_error!("The platform you're compiling for is not supported by winit");

src/platform_impl/websys/event.rs

@@ -0,0 +1,19 @@
+use std::convert::From;
+
+use ::event::WindowEvent as WindowEvent;
+use ::event::DeviceId as WDeviceId;
+use ::event::{ElementState, MouseButton};
+
+use ::web_sys::MouseEvent;
+use super::window::DeviceId;
+
+impl From<MouseEvent> for WindowEvent {
+    fn from(event: MouseEvent) -> Self {
+        WindowEvent::MouseInput {
+            device_id: WDeviceId(DeviceId::dummy()),
+            state: ElementState::Pressed,
+            button: MouseButton::Left,
+            modifiers: Default::default()
+        }
+    }
+}