macOS: Merge window and delegate state (#3391)

Previously we had a sort of artificial split between these, but both were accessing each other's state, since it's really the same state!
It was especially difficult to follow what happens to the fullscreen state.
So instead, we basically merge the window and the delegate files.

This does unfortunately screw a bit with the git history, apologies to whoever reads this in the future!

src/platform_impl/macos/event_loop.rs

@@ -75,7 +75,7 @@ impl PanicInfo {
 #[derive(Debug)]
 pub struct EventLoopWindowTarget {
     delegate: Id<ApplicationDelegate>,
-    mtm: MainThreadMarker,
+    pub(super) mtm: MainThreadMarker,
 }
 
 impl EventLoopWindowTarget {

src/platform_impl/macos/mod.rs

@@ -22,7 +22,8 @@ pub(crate) use self::{
         EventLoop, EventLoopProxy, EventLoopWindowTarget, PlatformSpecificEventLoopAttributes,
     },
     monitor::{MonitorHandle, VideoModeHandle},
-    window::{PlatformSpecificWindowBuilderAttributes, WindowId},
+    window::WindowId,
+    window_delegate::PlatformSpecificWindowBuilderAttributes,
 };
 use crate::event::DeviceId as RootDeviceId;
 

src/platform_impl/macos/view.rs

@@ -34,7 +34,7 @@ use crate::{
         WindowEvent,
     },
     keyboard::{Key, KeyCode, KeyLocation, ModifiersState, NamedKey},
-    platform::macos::{OptionAsAlt, WindowExtMacOS},
+    platform::macos::OptionAsAlt,
 };
 
 #[derive(Debug)]
@@ -141,6 +141,9 @@ pub struct ViewState {
 
     // Weak reference because the window keeps a strong reference to the view
     _ns_window: WeakId<WinitWindow>,
+
+    /// The state of the `Option` as `Alt`.
+    option_as_alt: Cell<OptionAsAlt>,
 }
 
 declare_class!(
@@ -437,7 +440,7 @@ declare_class!(
             // Get the characters from the event.
             let old_ime_state = self.ivars().ime_state.get();
             self.ivars().forward_key_to_app.set(false);
-            let event = replace_event(event, self.window().option_as_alt());
+            let event = replace_event(event, self.option_as_alt());
 
             // The `interpretKeyEvents` function might call
             // `setMarkedText`, `insertText`, and `doCommandBySelector`.
@@ -483,7 +486,7 @@ declare_class!(
         fn key_up(&self, event: &NSEvent) {
             trace_scope!("keyUp:");
 
-            let event = replace_event(event, self.window().option_as_alt());
+            let event = replace_event(event, self.option_as_alt());
             self.update_modifiers(&event, false);
 
             // We want to send keyboard input when we are currently in the ground state.
@@ -759,11 +762,16 @@ declare_class!(
 );
 
 impl WinitView {
-    pub(super) fn new(window: &WinitWindow, accepts_first_mouse: bool) -> Id<Self> {
+    pub(super) fn new(
+        window: &WinitWindow,
+        accepts_first_mouse: bool,
+        option_as_alt: OptionAsAlt,
+    ) -> Id<Self> {
         let mtm = MainThreadMarker::from(window);
         let this = mtm.alloc().set_ivars(ViewState {
             accepts_first_mouse,
             _ns_window: WeakId::new(&window.retain()),
+            option_as_alt: Cell::new(option_as_alt),
             ..Default::default()
         });
         let this: Id<Self> = unsafe { msg_send_id![super(this), init] };
@@ -883,6 +891,14 @@ impl WinitView {
         }
     }
 
+    pub(super) fn set_option_as_alt(&self, value: OptionAsAlt) {
+        self.ivars().option_as_alt.set(value)
+    }
+
+    pub(super) fn option_as_alt(&self) -> OptionAsAlt {
+        self.ivars().option_as_alt.get()
+    }
+
     /// Update modifiers if `event` has something different
     fn update_modifiers(&self, ns_event: &NSEvent, is_flags_changed_event: bool) {
         use ElementState::{Pressed, Released};