Implement web_sys::Canvas event listeners

src/platform_impl/web/web_sys/mod.rs

@@ -1,11 +1,16 @@
 mod canvas;
 mod document;
+mod event;
 mod timeout;
 
 pub use self::canvas::Canvas;
 pub use self::document::Document;
 pub use self::timeout::Timeout;
 
+use crate::platform::web::WindowExtWebSys;
+use crate::window::Window;
+use web_sys::HtmlCanvasElement;
+
 pub fn request_animation_frame<F>(f: F)
 where
     F: Fn(),
@@ -15,3 +20,9 @@ where
 pub fn throw(msg: &str) {
     wasm_bindgen::throw_str(msg);
 }
+
+impl WindowExtWebSys for Window {
+    fn canvas(&self) -> HtmlCanvasElement {
+        self.window.canvas().raw().clone()
+    }
+}