WIP: Provide an implementation for the HasRawWindowHandle trait in Ru…

…st for sixtyfps::Window

RWH is the de-facto standard crate in Rust to express window handles
(and associated windowing system connections). This should be safe to
use in the public API.

This patch implements RWH for the GL backend.

cc #877

sixtyfps_runtime/corelib/Cargo.toml

@@ -60,7 +60,7 @@ pin-project = "1"
 atomic-polyfill = { version = "0.1.5" }
 num-traits = { version = "0.2", default-features = false }
 sixtyfps-common = { version = "=0.2.0", path = "../common" }
-
+raw-window-handle = { version = "0.4.2" }
 defmt = { version = "0.3.0", optional = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]

sixtyfps_runtime/corelib/window.rs

@@ -17,7 +17,7 @@ use core::pin::Pin;
 /// This trait represents the interface that the generated code and the run-time
 /// require in order to implement functionality such as device-independent pixels,
 /// window resizing and other typically windowing system related tasks.
-pub trait PlatformWindow {
+pub trait PlatformWindow: raw_window_handle::HasRawWindowHandle {
     /// Registers the window with the windowing system.
     fn show(self: Rc<Self>);
     /// De-registers the window from the windowing system.
@@ -591,6 +591,13 @@ pub mod api {
             self.0.hide();
         }
     }
+
+    unsafe impl raw_window_handle::HasRawWindowHandle for Window {
+        #![allow(unsafe_code)]
+        fn raw_window_handle(&self) -> raw_window_handle::RawWindowHandle {
+            self.0.raw_window_handle()
+        }
+    }
 }
 
 impl WindowHandleAccess for api::Window {

sixtyfps_runtime/rendering_backends/gl/Cargo.toml

@@ -50,6 +50,7 @@ ttf-parser = "0.14.0"
 unicode-script = "0.5.3"
 cfg-if = "1"
 winit = { version = "0.26", default-features = false }
+raw-window-handle = { version = "0.4.2" }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 web_sys = { version = "0.3", package = "web-sys", features=["console", "WebGlContextAttributes"] }

sixtyfps_runtime/rendering_backends/gl/glwindow.rs

@@ -621,6 +621,16 @@ impl PlatformWindow for GLWindow {
     }
 }
 
+unsafe impl raw_window_handle::HasRawWindowHandle for GLWindow {
+    fn raw_window_handle(&self) -> raw_window_handle::RawWindowHandle {
+        if let Some(mapped_window) = self.borrow_mapped_window() {
+            mapped_window.opengl_context.window().raw_window_handle()
+        } else {
+            raw_window_handle::RawWindowHandle::Xcb(raw_window_handle::XcbHandle::empty())
+        }
+    }
+}
+
 struct MappedWindow {
     canvas: Option<CanvasRc>,
     opengl_context: crate::OpenGLContext,

sixtyfps_runtime/rendering_backends/qt/Cargo.toml

@@ -30,6 +30,7 @@ euclid = "0.22.1"
 pin-weak = "1"
 once_cell = "1"
 lyon_path = "0.17"
+raw-window-handle = { version = "0.4.2" }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 qttypes = { version = "0.2.5", default-features = false }

sixtyfps_runtime/rendering_backends/qt/qt_window.rs

@@ -1512,6 +1512,12 @@ impl PlatformWindow for QtWindow {
     }
 }
 
+unsafe impl raw_window_handle::HasRawWindowHandle for QtWindow {
+    fn raw_window_handle(&self) -> raw_window_handle::RawWindowHandle {
+        unimplemented!()
+    }
+}
+
 fn get_font(request: FontRequest) -> QFont {
     let family: qttypes::QString = request.family.unwrap_or_default().as_str().into();
     let pixel_size: f32 = request.pixel_size.unwrap_or(0.);

sixtyfps_runtime/rendering_backends/testing/Cargo.toml

@@ -18,3 +18,4 @@ path = "lib.rs"
 [dependencies]
 sixtyfps-corelib = { version = "=0.2.0", path = "../../corelib" }
 image = { version = "0.23.14", default-features = false, features = ["png"] }
+raw-window-handle = { version = "0.4.2" }

sixtyfps_runtime/rendering_backends/testing/lib.rs

@@ -157,6 +157,12 @@ impl PlatformWindow for TestingWindow {
     }
 }
 
+unsafe impl raw_window_handle::HasRawWindowHandle for TestingWindow {
+    fn raw_window_handle(&self) -> raw_window_handle::RawWindowHandle {
+        unimplemented!()
+    }
+}
+
 /// Initialize the testing backend.
 /// Must be called before any call that would otherwise initialize the rendering backend.
 /// Calling it when the rendering backend is already initialized will have no effects