Run Window::set_ime_position on main thread on macOS

Fixes #2756.

CHANGELOG.md

@@ -9,6 +9,7 @@ And please only add new entries to the top of this list, right below the `# Unre
 # Unreleased
 
 - On macOS, fixed potential panic when getting refresh rate.
+- On macOS, fix crash when calling `Window::set_ime_position` from another thread.
 
 # 0.28.3
 

src/platform_impl/macos/util/async.rs

@@ -2,10 +2,10 @@ use std::ops::Deref;
 
 use dispatch::Queue;
 use objc2::foundation::{is_main_thread, CGFloat, NSPoint, NSSize, NSString};
-use objc2::rc::autoreleasepool;
+use objc2::rc::{autoreleasepool, Id};
 
 use crate::{
-    dpi::LogicalSize,
+    dpi::{LogicalPosition, LogicalSize},
     platform_impl::platform::{
         appkit::{NSScreen, NSWindow, NSWindowLevel, NSWindowStyleMask},
         ffi,
@@ -201,3 +201,11 @@ pub(crate) fn close_sync(window: &NSWindow) {
         });
     });
 }
+
+pub(crate) fn set_ime_position_sync(window: &WinitWindow, logical_spot: LogicalPosition<f64>) {
+    let window = MainThreadSafe(window);
+    run_on_main(move || {
+        // TODO(madsmtm): Remove the need for this
+        unsafe { Id::from_shared(window.view()) }.set_ime_position(logical_spot);
+    });
+}

src/platform_impl/macos/window.rs

@@ -1165,8 +1165,7 @@ impl WinitWindow {
     pub fn set_ime_position(&self, spot: Position) {
         let scale_factor = self.scale_factor();
         let logical_spot = spot.to_logical(scale_factor);
-        // TODO(madsmtm): Remove the need for this
-        unsafe { Id::from_shared(self.view()) }.set_ime_position(logical_spot);
+        util::set_ime_position_sync(self, logical_spot);
     }
 
     #[inline]