iOS: Split classes in view.rs into separate files (#3511)

* Move application delegate to its own file
* Move window subclass to window.rs
* Split view controller to separate file

src/platform_impl/ios/app_delegate.rs

@@ -0,0 +1,103 @@
+use icrate::Foundation::{MainThreadMarker, NSObject, NSObjectProtocol};
+use objc2::{declare_class, mutability, ClassType, DeclaredClass};
+
+use super::app_state::{self, EventWrapper};
+use super::uikit::{UIApplication, UIWindow};
+use super::window::WinitUIWindow;
+use crate::{
+    event::{Event, WindowEvent},
+    window::WindowId as RootWindowId,
+};
+
+declare_class!(
+    pub struct AppDelegate;
+
+    unsafe impl ClassType for AppDelegate {
+        type Super = NSObject;
+        type Mutability = mutability::InteriorMutable;
+        const NAME: &'static str = "WinitApplicationDelegate";
+    }
+
+    impl DeclaredClass for AppDelegate {}
+
+    // UIApplicationDelegate protocol
+    unsafe impl AppDelegate {
+        #[method(application:didFinishLaunchingWithOptions:)]
+        fn did_finish_launching(&self, _application: &UIApplication, _: *mut NSObject) -> bool {
+            app_state::did_finish_launching(MainThreadMarker::new().unwrap());
+            true
+        }
+
+        #[method(applicationDidBecomeActive:)]
+        fn did_become_active(&self, _application: &UIApplication) {
+            let mtm = MainThreadMarker::new().unwrap();
+            app_state::handle_nonuser_event(mtm, EventWrapper::StaticEvent(Event::Resumed))
+        }
+
+        #[method(applicationWillResignActive:)]
+        fn will_resign_active(&self, _application: &UIApplication) {
+            let mtm = MainThreadMarker::new().unwrap();
+            app_state::handle_nonuser_event(mtm, EventWrapper::StaticEvent(Event::Suspended))
+        }
+
+        #[method(applicationWillEnterForeground:)]
+        fn will_enter_foreground(&self, application: &UIApplication) {
+            self.send_occluded_event_for_all_windows(application, false);
+        }
+
+        #[method(applicationDidEnterBackground:)]
+        fn did_enter_background(&self, application: &UIApplication) {
+            self.send_occluded_event_for_all_windows(application, true);
+        }
+
+        #[method(applicationWillTerminate:)]
+        fn will_terminate(&self, application: &UIApplication) {
+            let mut events = Vec::new();
+            for window in application.windows().iter() {
+                if window.is_kind_of::<WinitUIWindow>() {
+                    // SAFETY: We just checked that the window is a `winit` window
+                    let window = unsafe {
+                        let ptr: *const UIWindow = window;
+                        let ptr: *const WinitUIWindow = ptr.cast();
+                        &*ptr
+                    };
+                    events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+                        window_id: RootWindowId(window.id()),
+                        event: WindowEvent::Destroyed,
+                    }));
+                }
+            }
+            let mtm = MainThreadMarker::new().unwrap();
+            app_state::handle_nonuser_events(mtm, events);
+            app_state::terminated(mtm);
+        }
+
+        #[method(applicationDidReceiveMemoryWarning:)]
+        fn did_receive_memory_warning(&self, _application: &UIApplication) {
+            let mtm = MainThreadMarker::new().unwrap();
+            app_state::handle_nonuser_event(mtm, EventWrapper::StaticEvent(Event::MemoryWarning))
+        }
+    }
+);
+
+impl AppDelegate {
+    fn send_occluded_event_for_all_windows(&self, application: &UIApplication, occluded: bool) {
+        let mut events = Vec::new();
+        for window in application.windows().iter() {
+            if window.is_kind_of::<WinitUIWindow>() {
+                // SAFETY: We just checked that the window is a `winit` window
+                let window = unsafe {
+                    let ptr: *const UIWindow = window;
+                    let ptr: *const WinitUIWindow = ptr.cast();
+                    &*ptr
+                };
+                events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+                    window_id: RootWindowId(window.id()),
+                    event: WindowEvent::Occluded(occluded),
+                }));
+            }
+        }
+        let mtm = MainThreadMarker::new().unwrap();
+        app_state::handle_nonuser_events(mtm, events);
+    }
+}