iOS: Refactor event handling to share code with macOS

src/platform_impl/apple/appkit/app_state.rs

@@ -8,7 +8,7 @@ use std::time::Instant;
 use objc2_app_kit::{NSApplication, NSApplicationActivationPolicy};
 use objc2_foundation::{MainThreadMarker, NSNotification};
 
-use super::event_handler::EventHandler;
+use super::super::event_handler::EventHandler;
 use super::event_loop::{stop_app_immediately, ActiveEventLoop, PanicInfo};
 use super::observer::{EventLoopWaker, RunLoop};
 use super::{menu, WindowId};
@@ -291,7 +291,7 @@ impl AppState {
         callback: impl FnOnce(&mut dyn ApplicationHandler, &ActiveEventLoop),
     ) {
         let event_loop = ActiveEventLoop { app_state: Rc::clone(self), mtm: self.mtm };
-        self.event_handler.handle(callback, &event_loop);
+        self.event_handler.handle(|app| callback(app, &event_loop));
     }
 
     /// dispatch `NewEvents(Init)` + `Resumed`

src/platform_impl/apple/appkit/mod.rs

@@ -5,7 +5,6 @@ mod app;
 mod app_state;
 mod cursor;
 mod event;
-mod event_handler;
 mod event_loop;
 mod ffi;
 mod menu;

src/platform_impl/apple/appkit/event_handler.rs → src/platform_impl/apple/event_handler.rs

@@ -2,8 +2,9 @@ use std::cell::RefCell;
 use std::{fmt, mem};
 
 use crate::application::ApplicationHandler;
-use crate::platform_impl::ActiveEventLoop;
 
+/// A helper type for storing a reference to `ApplicationHandler`, allowing interior mutable access
+/// to it within the execution of a closure.
 #[derive(Default)]
 pub(crate) struct EventHandler {
     /// This can be in the following states:
@@ -100,19 +101,17 @@ impl EventHandler {
         // soundness.
     }
 
+    #[cfg(target_os = "macos")]
     pub(crate) fn in_use(&self) -> bool {
         self.inner.try_borrow().is_err()
     }
 
+    #[cfg(target_os = "macos")]
     pub(crate) fn ready(&self) -> bool {
         matches!(self.inner.try_borrow().as_deref(), Ok(Some(_)))
     }
 
-    pub(crate) fn handle(
-        &self,
-        callback: impl FnOnce(&mut dyn ApplicationHandler, &ActiveEventLoop),
-        event_loop: &ActiveEventLoop,
-    ) {
+    pub(crate) fn handle(&self, callback: impl FnOnce(&mut dyn ApplicationHandler)) {
         match self.inner.try_borrow_mut().as_deref_mut() {
             Ok(Some(user_app)) => {
                 // It is important that we keep the reference borrowed here,
@@ -121,7 +120,7 @@ impl EventHandler {
                 //
                 // If the handler unwinds, the `RefMut` will ensure that the
                 // handler is no longer borrowed.
-                callback(*user_app, event_loop);
+                callback(*user_app);
             },
             Ok(None) => {
                 // `NSApplication`, our app state and this handler are all

src/platform_impl/apple/mod.rs

@@ -2,6 +2,7 @@
 
 #[cfg(target_os = "macos")]
 mod appkit;
+mod event_handler;
 mod notification_center;
 #[cfg(not(target_os = "macos"))]
 mod uikit;