Add wasm-bindgen v0.2 handles for web_sys::HtmlCanvasElement and web_sys::OffscreenCanvas

.github/workflows/ci.yml

@@ -40,19 +40,15 @@ jobs:
         with:
           rust-version: ${{ matrix.rust_version }}
 
-      - run: rustup target add x86_64-linux-android
+      - run: rustup target add wasm32-unknown-unknown
 
       - name: Check documentation
         run: cargo doc --no-deps --document-private-items
 
-      - name: Run tests
-        run: cargo test --verbose
-
-      - name: Run tests with std
-        run: cargo test --verbose --features std
+      - uses: taiki-e/install-action@cargo-hack
 
-      - name: Check on Android
-        run: cargo check --verbose --target x86_64-linux-android
+      - name: Run tests
+        run: cargo hack test --feature-powerset
 
-      - name: Check on Android with std
-        run: cargo check --verbose --target x86_64-linux-android --features std
+      - name: Run tests for wasm32-unknown-unknown
+        run: cargo hack check --target wasm32-unknown-unknown --feature-powerset

Cargo.toml

@@ -15,6 +15,15 @@ rust-version = "1.64"
 alloc = []
 std = ["alloc"]
 
+# Allow conversion methods to/from WASM types using `wasm-bindgen` v0.2.
+wasm-bindgen-0-2 = ["wasm-bindgen", "std"]
+
+[target.'cfg(target_family = "wasm")'.dependencies.wasm-bindgen]
+version = "0.2.87"
+default-features = false
+features = ["std"]
+optional = true
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]

src/borrowed.rs

@@ -209,7 +209,7 @@ impl<H: HasWindowHandle + ?Sized> HasWindowHandle for alloc::sync::Arc<H> {
 ///
 /// This handle is guaranteed to be safe and valid. Get the underlying raw window handle with the
 /// [`HasRawWindowHandle`] trait.
-#[derive(PartialEq, Eq, Hash, Clone)]
+#[derive(PartialEq, Eq, Hash, Copy, Clone)]
 pub struct WindowHandle<'a> {
     raw: RawWindowHandle,
     _marker: PhantomData<&'a *const ()>,
@@ -237,13 +237,13 @@ impl<'a> WindowHandle<'a> {
 
 unsafe impl HasRawWindowHandle for WindowHandle<'_> {
     fn raw_window_handle(&self) -> Result<RawWindowHandle, HandleError> {
-        Ok(self.raw.clone())
+        Ok(self.raw)
     }
 }
 
 impl HasWindowHandle for WindowHandle<'_> {
     fn window_handle(&self) -> Result<Self, HandleError> {
-        Ok(self.clone())
+        Ok(*self)
     }
 }
 

src/lib.rs

@@ -1,5 +1,7 @@
 #![no_std]
 #![cfg_attr(docsrs, feature(doc_cfg))]
+#![allow(clippy::new_without_default)]
+#![deny(unsafe_op_in_unsafe_fn)]
 
 //! Interoperability library for Rust Windowing applications.
 //!
@@ -51,7 +53,9 @@ pub use unix::{
     DrmDisplayHandle, DrmWindowHandle, GbmDisplayHandle, GbmWindowHandle, WaylandDisplayHandle,
     WaylandWindowHandle, XcbDisplayHandle, XcbWindowHandle, XlibDisplayHandle, XlibWindowHandle,
 };
-pub use web::{WebDisplayHandle, WebWindowHandle};
+pub use web::{
+    WebCanvasWindowHandle, WebDisplayHandle, WebOffscreenCanvasWindowHandle, WebWindowHandle,
+};
 pub use windows::{Win32WindowHandle, WinRtWindowHandle, WindowsDisplayHandle};
 
 use core::fmt;
@@ -120,7 +124,7 @@ unsafe impl<T: HasRawWindowHandle + ?Sized> HasRawWindowHandle for alloc::sync::
 /// [`RawWindowHandle::Xlib`] on macOS, it would just be weird, and probably
 /// requires something like XQuartz be used).
 #[non_exhaustive]
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum RawWindowHandle {
     /// A raw window handle for UIKit (Apple's non-macOS windowing library).
     ///
@@ -189,6 +193,20 @@ pub enum RawWindowHandle {
     /// ## Availability Hints
     /// This variant is used on Wasm or asm.js targets when targeting the Web/HTML5.
     Web(WebWindowHandle),
+    /// A raw window handle for a Web canvas registered via [`wasm-bindgen`].
+    ///
+    /// ## Availability Hints
+    /// This variant is used on Wasm or asm.js targets when targeting the Web/HTML5.
+    ///
+    /// [`wasm-bindgen`]: https://crates.io/crates/wasm-bindgen
+    WebCanvas(WebCanvasWindowHandle),
+    /// A raw window handle for a Web offscreen canvas registered via [`wasm-bindgen`].
+    ///
+    /// ## Availability Hints
+    /// This variant is used on Wasm or asm.js targets when targeting the Web/HTML5.
+    ///
+    /// [`wasm-bindgen`]: https://crates.io/crates/wasm-bindgen
+    WebOffscreenCanvas(WebOffscreenCanvasWindowHandle),
     /// A raw window handle for Android NDK.
     ///
     /// ## Availability Hints

src/web.rs

@@ -1,3 +1,6 @@
+use core::ffi::c_void;
+use core::ptr::NonNull;
+
 /// Raw display handle for the Web.
 #[non_exhaustive]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -48,3 +51,147 @@ impl WebWindowHandle {
         Self { id }
     }
 }
+
+/// Raw window handle for a Web canvas registered via [`wasm-bindgen`].
+///
+/// [`wasm-bindgen`]: https://crates.io/crates/wasm-bindgen
+#[non_exhaustive]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct WebCanvasWindowHandle {
+    /// A pointer to the [`JsValue`] of an [`HtmlCanvasElement`].
+    ///
+    /// Note: This uses [`c_void`] to avoid depending on `wasm-bindgen`
+    /// directly.
+    ///
+    /// [`JsValue`]: https://docs.rs/wasm-bindgen/latest/wasm_bindgen/struct.JsValue.html
+    /// [`HtmlCanvasElement`]: https://docs.rs/web-sys/latest/web_sys/struct.HtmlCanvasElement.html
+    //
+    // SAFETY: Not using `JsValue` is sound because `wasm-bindgen` guarantees
+    // that there's only one version of itself in any given binary, and hence
+    // we can't have a type-confusion where e.g. one library used `JsValue`
+    // from `v0.2` of `wasm-bindgen`, and another used `JsValue` from `v1.0`;
+    // the binary will simply fail to compile!
+    //
+    // Reference: TODO
+    pub obj: NonNull<c_void>,
+}
+
+impl WebCanvasWindowHandle {
+    /// Create a new handle from a pointer to [`HtmlCanvasElement`].
+    ///
+    /// [`HtmlCanvasElement`]: https://docs.rs/web-sys/latest/web_sys/struct.HtmlCanvasElement.html
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use core::ffi::c_void;
+    /// # use core::ptr::NonNull;
+    /// # use raw_window_handle::WebCanvasWindowHandle;
+    /// # type HtmlCanvasElement = ();
+    /// # type JsValue = ();
+    /// let canvas: &HtmlCanvasElement;
+    /// # canvas = &();
+    /// let value: &JsValue = &canvas; // Deref to `JsValue`
+    /// let obj: NonNull<c_void> = NonNull::from(value).cast();
+    /// let mut handle = WebCanvasWindowHandle::new(obj);
+    /// ```
+    pub fn new(obj: NonNull<c_void>) -> Self {
+        Self { obj }
+    }
+}
+
+#[cfg(all(target_family = "wasm", feature = "wasm-bindgen-0-2"))]
+#[cfg_attr(
+    docsrs,
+    doc(cfg(all(target_family = "wasm", feature = "wasm-bindgen-0-2")))
+)]
+/// These implementations are only available when `wasm-bindgen-0-2` is enabled.
+impl WebCanvasWindowHandle {
+    /// Create a new `WebCanvasWindowHandle` from a [`wasm_bindgen::JsValue`].
+    ///
+    /// The `JsValue` should refer to a `HtmlCanvasElement`, and the lifetime
+    /// of the value should be at least as long as the lifetime of this.
+    pub fn from_wasm_bindgen_0_2(js_value: &wasm_bindgen::JsValue) -> Self {
+        Self::new(NonNull::from(js_value).cast())
+    }
+
+    /// Convert to the underlying [`wasm_bindgen::JsValue`].
+    ///
+    /// # Safety
+    ///
+    /// The inner pointer must be valid. This is ensured if this handle was
+    /// borrowed from [`WindowHandle`][crate::WindowHandle].
+    pub unsafe fn as_wasm_bindgen_0_2(&self) -> &wasm_bindgen::JsValue {
+        unsafe { self.obj.cast().as_ref() }
+    }
+}
+
+/// Raw window handle for a Web offscreen canvas registered via
+/// [`wasm-bindgen`].
+///
+/// [`wasm-bindgen`]: https://crates.io/crates/wasm-bindgen
+#[non_exhaustive]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct WebOffscreenCanvasWindowHandle {
+    /// A pointer to the [`JsValue`] of an [`OffscreenCanvas`].
+    ///
+    /// Note: This uses [`c_void`] to avoid depending on `wasm-bindgen`
+    /// directly.
+    ///
+    /// [`JsValue`]: https://docs.rs/wasm-bindgen/latest/wasm_bindgen/struct.JsValue.html
+    /// [`OffscreenCanvas`]: https://docs.rs/web-sys/latest/web_sys/struct.OffscreenCanvas.html
+    //
+    // SAFETY: See WebCanvasWindowHandle.
+    pub obj: NonNull<c_void>,
+}
+
+impl WebOffscreenCanvasWindowHandle {
+    /// Create a new handle from a pointer to an [`OffscreenCanvas`].
+    ///
+    /// [`OffscreenCanvas`]: https://docs.rs/web-sys/latest/web_sys/struct.OffscreenCanvas.html
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use core::ffi::c_void;
+    /// # use core::ptr::NonNull;
+    /// # use raw_window_handle::WebOffscreenCanvasWindowHandle;
+    /// # type OffscreenCanvas = ();
+    /// # type JsValue = ();
+    /// let canvas: &OffscreenCanvas;
+    /// # canvas = &();
+    /// let value: &JsValue = &canvas; // Deref to `JsValue`
+    /// let obj: NonNull<c_void> = NonNull::from(value).cast();
+    /// let mut handle = WebOffscreenCanvasWindowHandle::new(obj);
+    /// ```
+    pub fn new(obj: NonNull<c_void>) -> Self {
+        Self { obj }
+    }
+}
+
+#[cfg(all(target_family = "wasm", feature = "wasm-bindgen-0-2"))]
+#[cfg_attr(
+    docsrs,
+    doc(cfg(all(target_family = "wasm", feature = "wasm-bindgen-0-2")))
+)]
+/// These implementations are only available when `wasm-bindgen-0-2` is enabled.
+impl WebOffscreenCanvasWindowHandle {
+    /// Create a new `WebOffscreenCanvasWindowHandle` from a
+    /// [`wasm_bindgen::JsValue`].
+    ///
+    /// The `JsValue` should refer to a `HtmlCanvasElement`, and the lifetime
+    /// of the value should be at least as long as the lifetime of this.
+    pub fn from_wasm_bindgen_0_2(js_value: &wasm_bindgen::JsValue) -> Self {
+        Self::new(NonNull::from(js_value).cast())
+    }
+
+    /// Convert to the underlying [`wasm_bindgen::JsValue`].
+    ///
+    /// # Safety
+    ///
+    /// The inner pointer must be valid. This is ensured if this handle was
+    /// borrowed from [`WindowHandle`][crate::WindowHandle].
+    pub unsafe fn as_wasm_bindgen_0_2(&self) -> &wasm_bindgen::JsValue {
+        unsafe { self.obj.cast().as_ref() }
+    }
+}