Draft web platform structure

src/platform_impl/web/web_sys/canvas.rs

@@ -0,0 +1,66 @@
+use crate::dpi::LogicalSize;
+use crate::error::OsError as RootOE;
+use crate::platform_impl::OsError;
+
+use wasm_bindgen::JsCast;
+use web_sys::HtmlCanvasElement;
+
+pub struct Canvas {
+    raw: HtmlCanvasElement,
+}
+
+impl Canvas {
+    pub fn create() -> Result<Self, RootOE> {
+        let window = web_sys::window().expect("Failed to obtain window");
+        let document = window.document().expect("Failed to obtain document");
+
+        let canvas: HtmlCanvasElement = document
+            .create_element("canvas")
+            .map_err(|_| os_error!(OsError("Failed to create canvas element".to_owned())))?
+            .unchecked_into();
+
+        document
+            .body()
+            .ok_or_else(|| os_error!(OsError("Failed to find body node".to_owned())))?
+            .append_child(&canvas)
+            .map_err(|_| os_error!(OsError("Failed to append canvas".to_owned())))?;
+
+        Ok(Canvas { raw: canvas })
+    }
+
+    pub fn set_attribute(&self, attribute: &str, value: &str) {
+        self.raw
+            .set_attribute(attribute, value)
+            .expect(&format!("Set attribute: {}", attribute));
+    }
+
+    pub fn position(&self) -> (f64, f64) {
+        let bounds = self.raw.get_bounding_client_rect();
+
+        (bounds.x(), bounds.y())
+    }
+
+    pub fn width(&self) -> f64 {
+        self.raw.width() as f64
+    }
+
+    pub fn height(&self) -> f64 {
+        self.raw.height() as f64
+    }
+
+    pub fn set_size(&self, size: LogicalSize) {
+        self.raw.set_width(size.width as u32);
+        self.raw.set_height(size.height as u32);
+    }
+
+    pub fn raw(&self) -> HtmlCanvasElement {
+        self.raw.clone()
+    }
+
+    pub fn on_mouse_out<F>(&self, f: F) {}
+    pub fn on_mouse_over<F>(&self, f: F) {}
+    pub fn on_mouse_up<F>(&self, f: F) {}
+    pub fn on_mouse_down<F>(&self, f: F) {}
+    pub fn on_mouse_move<F>(&self, f: F) {}
+    pub fn on_mouse_scroll<F>(&self, f: F) {}
+}