fix(ui): let macOS windows inherit app appearance

changelog.d/11095-macos-window-appearance.md

@@ -0,0 +1,5 @@
+### Fixed
+
+- macOS windows now inherit the application's effective appearance, allowing
+  `NSRequiresAquaSystemAppearance` to keep an app in light mode while preserving
+  the normal system appearance behavior by default.

crates/perry-ui-macos/Cargo.toml

@@ -106,3 +106,8 @@ harness = false
 name = "native_button_image_size"
 path = "tests/native_button_image_size.rs"
 harness = false
+
+[[test]]
+name = "native_window_appearance"
+path = "tests/native_window_appearance.rs"
+harness = false

crates/perry-ui-macos/src/app.rs

@@ -100,22 +100,9 @@ pub fn app_create(title_ptr: *const u8, width: f64, height: f64) -> i64 {
         let ns_title = NSString::from_str(&title);
         window.setTitle(&ns_title);
 
-        // Match window appearance to the system setting so native controls
-        // (NSTextField, NSPopUpButton, etc.) use the correct light/dark theme.
-        // isDarkMode() is called here (after NSApp exists) to get the correct value.
-        let is_dark = super::perry_system_is_dark_mode() != 0;
-        let appearance_name = if is_dark {
-            NSString::from_str("NSAppearanceNameDarkAqua")
-        } else {
-            NSString::from_str("NSAppearanceNameAqua")
-        };
-        let appearance_cls = objc2::runtime::AnyClass::get(c"NSAppearance").unwrap();
-        let appearance: *mut objc2::runtime::AnyObject = objc2::msg_send![
-            appearance_cls, appearanceNamed: &*appearance_name
-        ];
-        if !appearance.is_null() {
-            let _: () = objc2::msg_send![&*window, setAppearance: appearance];
-        }
+        // Keep the window's appearance unset so it inherits NSApp's effective
+        // appearance. AppKit follows the system by default and honors an
+        // app-bundle `NSRequiresAquaSystemAppearance` override (#11092).
 
         APPS.with(|a| {
             let mut apps = a.borrow_mut();

crates/perry-ui-macos/tests/native_window_appearance.rs

@@ -0,0 +1,43 @@
+// #11092 — a main window must leave its explicit appearance unset so it
+// inherits NSApp.effectiveAppearance. This lets AppKit follow the system by
+// default and honor NSRequiresAquaSystemAppearance from the app bundle.
+
+#[cfg(target_os = "macos")]
+fn main() {
+    use objc2::{msg_send, runtime::AnyObject};
+    use objc2_app_kit::NSApplication;
+    use objc2_foundation::MainThreadMarker;
+    use perry_runtime as _;
+
+    if std::env::args().any(|arg| arg == "--list") {
+        println!("native_window_appearance: test");
+        return;
+    }
+
+    let mtm = MainThreadMarker::new().expect("native window test runs on the main thread");
+    let app = NSApplication::sharedApplication(mtm);
+    let windows_before = app.windows().len();
+
+    perry_ui_macos::app::app_create(std::ptr::null(), 320.0, 200.0);
+
+    let windows = app.windows();
+    assert_eq!(
+        windows.len(),
+        windows_before + 1,
+        "app_create must register one NSWindow"
+    );
+    let window = windows
+        .iter()
+        .last()
+        .expect("app_create registered its NSWindow");
+    let appearance: *mut AnyObject = unsafe { msg_send![&**window, appearance] };
+    assert!(
+        appearance.is_null(),
+        "the main window must inherit NSApp.effectiveAppearance"
+    );
+
+    println!("PASS native window appearance inherits NSApp");
+}
+
+#[cfg(not(target_os = "macos"))]
+fn main() {}