From 0881a2830218337f59bfed1806eb6c085c19f7f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Amandus=20S=C3=B8ve=20Thorsrud?= <ama.thorsrud@gmail.com>
Date: Sat, 15 Apr 2023 01:58:36 +0200
Subject: [PATCH] Run `Window::set_ime_position` on main thread on macOS

Fixes #2756.
---
 CHANGELOG.md                          |  1 +
 src/platform_impl/macos/util/async.rs | 12 ++++++++++--
 src/platform_impl/macos/window.rs     |  3 +--
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e9e6bb3067..a6950dbd73 100644
--- a/CHANGELOG.md
+++ b/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
 
diff --git a/src/platform_impl/macos/util/async.rs b/src/platform_impl/macos/util/async.rs
index 6edbd8db6f..3cc9a4b46e 100644
--- a/src/platform_impl/macos/util/async.rs
+++ b/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);
+    });
+}
diff --git a/src/platform_impl/macos/window.rs b/src/platform_impl/macos/window.rs
index 6d3e79af96..69921ba78f 100644
--- a/src/platform_impl/macos/window.rs
+++ b/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]