Fix AppKitWindowHandle missing NSView

examples/raw-window-handle-with-wgpu/main.rs

@@ -4,7 +4,7 @@ extern crate sdl2;
 extern crate wgpu;
 
 use std::borrow::Cow;
-use wgpu::{SurfaceError, SurfaceTexture};
+use wgpu::SurfaceError;
 
 use sdl2::event::{Event, WindowEvent};
 use sdl2::keyboard::Keycode;
@@ -19,6 +19,7 @@ fn main() -> Result<(), String> {
         .window("Raw Window Handle Example", 800, 600)
         .position_centered()
         .resizable()
+        .metal_view()
         .build()
         .map_err(|e| e.to_string())?;
     let (width, height) = window.size();
@@ -138,10 +139,10 @@ fn main() -> Result<(), String> {
             }
         }
 
-        let mut frame = match surface.get_current_texture() {
+        let frame = match surface.get_current_texture() {
             Ok(frame) => frame,
             Err(err) => {
-                let reason = match (err) {
+                let reason = match err {
                     SurfaceError::Timeout => "Timeout",
                     SurfaceError::Outdated => "Outdated",
                     SurfaceError::Lost => "Lost",

src/sdl2/raw_window_handle.rs

@@ -84,7 +84,11 @@ unsafe impl HasRawWindowHandle for Window {
 
                 let mut handle = AppKitWindowHandle::empty();
                 handle.ns_window = unsafe { wm_info.info.cocoa }.window as *mut libc::c_void;
-                handle.ns_view = 0 as *mut libc::c_void; // consumer of RawWindowHandle should determine this
+                handle.ns_view = if self.context().metal_view.is_null() {
+                    panic!("metal_view not initialized, please call WindowBuilder::metal_view() when building the window");
+                } else {
+                    self.context().metal_view
+                };
 
                 RawWindowHandle::AppKit(handle)
             }
@@ -130,7 +134,7 @@ unsafe impl HasRawDisplayHandle for Window {
         // since SDL_GetWindowWMInfo will fail on emscripten
         if cfg!(target_os = "emscripten") {
             use self::raw_window_handle::WebDisplayHandle;
-            let mut handle = WebDisplayHandle::empty();
+            let handle = WebDisplayHandle::empty();
             return RawDisplayHandle::Web(handle);
         }
 
@@ -187,7 +191,7 @@ unsafe impl HasRawDisplayHandle for Window {
             #[cfg(target_os = "macos")]
             SDL_SYSWM_COCOA => {
                 use self::raw_window_handle::AppKitDisplayHandle;
-                let mut handle = AppKitDisplayHandle::empty();
+                let handle = AppKitDisplayHandle::empty();
                 RawDisplayHandle::AppKit(handle)
             }
             #[cfg(any(target_os = "ios"))]
@@ -204,7 +208,7 @@ unsafe impl HasRawDisplayHandle for Window {
 
                 let mut handle = AndroidDisplayHandle::empty();
                 handle.a_native_window =
-                unsafe { wm_info.info.android }.window as *mut libc::c_void;
+                    unsafe { wm_info.info.android }.window as *mut libc::c_void;
 
                 RawDisplayHandle::Android(handle)
             }

src/sdl2/video.rs

@@ -547,23 +547,30 @@ impl GLContext {
 pub struct WindowContext {
     subsystem: VideoSubsystem,
     raw: *mut sys::SDL_Window,
+    pub(crate) metal_view: sys::SDL_MetalView,
 }
 
 impl Drop for WindowContext {
     #[inline]
     #[doc(alias = "SDL_DestroyWindow")]
     fn drop(&mut self) {
-        unsafe { sys::SDL_DestroyWindow(self.raw) };
+        unsafe {
+            if !self.metal_view.is_null() {
+                sys::SDL_Metal_DestroyView(self.metal_view);
+            }
+            sys::SDL_DestroyWindow(self.raw)
+        };
     }
 }
 
 impl WindowContext {
     #[inline]
     /// Unsafe if the `*mut SDL_Window` is used after the `WindowContext` is dropped
-    pub unsafe fn from_ll(subsystem: VideoSubsystem, raw: *mut sys::SDL_Window) -> WindowContext {
+    pub unsafe fn from_ll(subsystem: VideoSubsystem, raw: *mut sys::SDL_Window, metal_view: sys::SDL_MetalView) -> WindowContext {
         WindowContext {
             subsystem: subsystem.clone(),
             raw,
+            metal_view,
         }
     }
 }
@@ -1098,6 +1105,7 @@ pub struct WindowBuilder {
     x: WindowPos,
     y: WindowPos,
     window_flags: u32,
+    create_metal_view: bool,
     /// The window builder cannot be built on a non-main thread, so prevent cross-threaded moves and references.
     /// `!Send` and `!Sync`,
     subsystem: VideoSubsystem,
@@ -1114,6 +1122,7 @@ impl WindowBuilder {
             y: WindowPos::Undefined,
             window_flags: 0,
             subsystem: v.clone(),
+            create_metal_view: false,
         }
     }
 
@@ -1143,11 +1152,16 @@ impl WindowBuilder {
                 raw_height,
                 self.window_flags,
             );
+            let mut metal_view = 0 as sys::SDL_MetalView;
+            #[cfg(target_os="macos")]
+            if self.create_metal_view {
+                metal_view = sys::SDL_Metal_CreateView(raw);
+            }
 
             if raw.is_null() {
                 Err(SdlError(get_error()))
             } else {
-                Ok(Window::from_ll(self.subsystem.clone(), raw))
+                Ok(Window::from_ll(self.subsystem.clone(), raw, metal_view))
             }
         }
     }
@@ -1243,6 +1257,14 @@ impl WindowBuilder {
         self.window_flags |= sys::SDL_WindowFlags::SDL_WINDOW_ALLOW_HIGHDPI as u32;
         self
     }
+
+    /// Create a SDL_MetalView when constructing the window.
+    /// This is required when using the raw_window_handle feature on MacOS.
+    /// Has no effect no other platforms.
+    pub fn metal_view(&mut self) -> &mut WindowBuilder {
+        self.create_metal_view = true;
+        self
+    }
 }
 
 impl From<Window> for CanvasBuilder {
@@ -1261,8 +1283,8 @@ impl Window {
     }
 
     #[inline]
-    pub unsafe fn from_ll(subsystem: VideoSubsystem, raw: *mut sys::SDL_Window) -> Window {
-        let context = WindowContext::from_ll(subsystem, raw);
+    pub unsafe fn from_ll(subsystem: VideoSubsystem, raw: *mut sys::SDL_Window, metal_view: sys::SDL_MetalView) -> Window {
+        let context = WindowContext::from_ll(subsystem, raw, metal_view);
         context.into()
     }