Add cursor hittest window functionality (#2232)

Co-authored-by: z4122 <412213484@qq.com>
Co-authored-by: Kirill Chibisov <contact@kchibisov.com>

src/platform_impl/macos/util/async.rs

@@ -10,7 +10,7 @@ use cocoa::{
 };
 use dispatch::Queue;
 use objc::rc::autoreleasepool;
-use objc::runtime::{BOOL, NO};
+use objc::runtime::{BOOL, NO, YES};
 
 use crate::{
     dpi::LogicalSize,
@@ -93,6 +93,14 @@ pub unsafe fn set_level_async(ns_window: id, level: ffi::NSWindowLevel) {
     });
 }
 
+// `setIgnoresMouseEvents_:` isn't thread-safe, and fails silently.
+pub unsafe fn set_ignore_mouse_events(ns_window: id, ignore: bool) {
+    let ns_window = MainThreadSafe(ns_window);
+    Queue::main().exec_async(move || {
+        ns_window.setIgnoresMouseEvents_(if ignore { YES } else { NO });
+    });
+}
+
 // `toggleFullScreen` is thread-safe, but our additional logic to account for
 // window styles isn't.
 pub unsafe fn toggle_full_screen_async(

src/platform_impl/macos/window.rs

@@ -678,6 +678,15 @@ impl UnownedWindow {
         Ok(())
     }
 
+    #[inline]
+    pub fn set_cursor_hittest(&self, hittest: bool) -> Result<(), ExternalError> {
+        unsafe {
+            util::set_ignore_mouse_events(*self.ns_window, !hittest);
+        }
+
+        Ok(())
+    }
+
     pub(crate) fn is_zoomed(&self) -> bool {
         // because `isZoomed` doesn't work if the window's borderless,
         // we make it resizable temporalily.