winit-appkit 0.31.0-beta.3

#![allow(clippy::unnecessary_cast)]
use std::cell::{Cell, RefCell};
use std::collections::VecDeque;
use std::ffi::c_void;
use std::ptr;
use std::rc::Rc;
use std::sync::{Arc, Mutex};

use dispatch2::MainThreadBound;
use dpi::{
    LogicalInsets, LogicalPosition, LogicalSize, PhysicalInsets, PhysicalPosition, PhysicalSize,
    Position, Size,
};
use objc2::rc::{Retained, autoreleasepool};
use objc2::runtime::{AnyObject, ProtocolObject};
use objc2::{
    ClassType, DefinedClass, MainThreadMarker, MainThreadOnly, Message, available, define_class,
    msg_send, sel,
};
use objc2_app_kit::{
    NSAppKitVersionNumber, NSAppKitVersionNumber10_12, NSAppearance, NSAppearanceCustomization,
    NSAppearanceNameAqua, NSApplication, NSApplicationPresentationOptions,
    NSAutoresizingMaskOptions, NSBackingStoreType, NSColor, NSDragOperation, NSDraggingContext,
    NSDraggingDestination, NSDraggingInfo, NSDraggingSession, NSDraggingSource,
    NSPasteboardTypeFileURL, NSPasteboardTypeHTML, NSPasteboardTypePNG, NSPasteboardTypeSound,
    NSPasteboardTypeString, NSPasteboardTypeTIFF, NSRequestUserAttentionType, NSScreen, NSToolbar,
    NSView, NSViewFrameDidChangeNotification, NSWindow, NSWindowButton, NSWindowCollectionBehavior,
    NSWindowDelegate, NSWindowLevel, NSWindowOcclusionState, NSWindowOrderingMode,
    NSWindowSharingType, NSWindowStyleMask, NSWindowTabbingMode, NSWindowTitleVisibility,
    NSWindowToolbarStyle,
};
#[cfg(not(feature = "private-apple-apis"))]
use objc2_app_kit::{
    NSVisualEffectBlendingMode, NSVisualEffectMaterial, NSVisualEffectState, NSVisualEffectView,
};
use objc2_core_foundation::{CGFloat, CGPoint};
use objc2_core_graphics::{
    CGAcquireDisplayFadeReservation, CGAssociateMouseAndMouseCursorPosition, CGDisplayCapture,
    CGDisplayFade, CGDisplayRelease, CGDisplaySetDisplayMode, CGReleaseDisplayFadeReservation,
    CGRestorePermanentDisplayConfiguration, CGShieldingWindowLevel, CGWarpMouseCursorPosition,
    kCGDisplayBlendNormal, kCGDisplayBlendSolidColor, kCGDisplayFadeReservationInvalidToken,
    kCGFloatingWindowLevel, kCGNormalWindowLevel,
};
use objc2_foundation::{
    NSArray, NSDictionary, NSEdgeInsets, NSKeyValueChangeKey, NSKeyValueChangeNewKey,
    NSKeyValueChangeOldKey, NSKeyValueObservingOptions, NSNotificationCenter, NSObject,
    NSObjectNSDelayedPerforming, NSObjectNSKeyValueObserverRegistration, NSObjectProtocol, NSPoint,
    NSRect, NSSize, NSString, ns_string,
};
use tracing::{debug_span, trace, warn};
use winit_common::core_foundation::MainRunLoop;
use winit_common::positioner::place_window;
use winit_core::cursor::Cursor;
use winit_core::data_transfer::DataTransferId;
use winit_core::error::{NotSupportedError, RequestError};
use winit_core::event::{SurfaceSizeWriter, WindowEvent};
use winit_core::icon::Icon;
use winit_core::monitor::{Fullscreen, MonitorHandle as CoreMonitorHandle, MonitorHandleProvider};
use winit_core::window::{
    CursorGrabMode, ImeCapabilities, ImeRequest, ImeRequestError, ResizeDirection, Theme,
    UserAttentionType, WindowAttributes, WindowButtons, WindowId, WindowLevel, WindowPositioner,
    WindowType,
};

use super::app_state::AppState;
use super::cursor::{CustomCursor, cursor_from_icon};
use super::monitor::{self, MonitorHandle, flip_window_screen_coordinates, get_display_id};
use super::util::cgerr;
use super::view::WinitView;
use super::window::{WinitPanel, WinitWindow, window_id};
use crate::app_state::DragState;
use crate::dnd::{
    dnd_action_to_ns_drag_operation, ns_drag_operation_to_dnd_action, preferred_drag_operation,
};
use crate::{BlurMaterial, OptionAsAlt, WindowAttributesMacOS, WindowExtMacOS};

#[derive(Debug)]
pub(crate) struct State {
    /// Strong reference to the global application state.
    app_state: Rc<AppState>,

    window: Retained<NSWindow>,

    view: Retained<WinitView>,

    #[cfg(not(feature = "private-apple-apis"))]
    blur_view: RefCell<Option<Retained<NSVisualEffectView>>>,

    blur_material: Cell<BlurMaterial>,

    // During `windowDidResize`, we use this to only send Moved if the position changed.
    //
    // This is expressed in desktop coordinates, and flipped to match Winit's coordinate system.
    previous_position: Cell<NSPoint>,

    // Used to prevent redundant events.
    previous_scale_factor: Cell<f64>,

    /// The current resize increments for the window content.
    surface_resize_increments: Cell<NSSize>,
    /// Whether the window is showing decorations.
    decorations: Cell<bool>,
    resizable: Cell<bool>,
    maximized: Cell<bool>,

    /// Presentation options saved before entering `set_simple_fullscreen`, and
    /// restored upon exiting it. Also used when transitioning from Borderless to
    /// Exclusive fullscreen in `set_fullscreen` because we need to disable the menu
    /// bar in exclusive fullscreen but want to restore the original options when
    /// transitioning back to borderless fullscreen.
    save_presentation_opts: Cell<Option<NSApplicationPresentationOptions>>,
    // This is set when WindowAttributes::with_fullscreen was set,
    // see comments of `window_did_fail_to_enter_fullscreen`
    initial_fullscreen: Cell<bool>,
    /// This field tracks the current fullscreen state of the window
    /// (as seen by `WindowDelegate`).
    fullscreen: RefCell<Option<Fullscreen>>,
    // If it is attempted to toggle fullscreen when in_fullscreen_transition is true,
    // Set target_fullscreen and do after fullscreen transition is end.
    target_fullscreen: RefCell<Option<Option<Fullscreen>>>,
    // This is true between windowWillEnterFullScreen and windowDidEnterFullScreen
    // or windowWillExitFullScreen and windowDidExitFullScreen.
    // We must not toggle fullscreen when this is true.
    in_fullscreen_transition: Cell<bool>,
    standard_frame: Cell<Option<NSRect>>,
    is_simple_fullscreen: Cell<bool>,
    saved_style: Cell<Option<NSWindowStyleMask>>,
    is_borderless_game: Cell<bool>,
    /// The window's role, used for creation/role behavior (decorations, activation/keyboard-grab
    /// default, initial placement). Does *not* determine whether the window is anchor-positioned
    /// -- see `anchored`.
    window_type: WindowType,
    /// Whether this window is positioned relative to its parent using the anchor/gravity/
    /// positioner system, either because it's a [`WindowType::Popup`] or because anchor
    /// attributes were set on a [`WindowType::Window`]. Gates the parent-relative coordinate
    /// frame used when applying anchor/gravity/positioner-offset changes.
    anchored: bool,
    positioner: RefCell<WindowPositioner>,
}

define_class!(
    #[unsafe(super(NSObject))]
    #[thread_kind = MainThreadOnly]
    #[name = "WinitWindowDelegate"]
    #[ivars = State]
    pub(crate) struct WindowDelegate;

    unsafe impl NSObjectProtocol for WindowDelegate {}

    unsafe impl NSWindowDelegate for WindowDelegate {
        #[unsafe(method(windowShouldClose:))]
        fn window_should_close(&self, _: Option<&AnyObject>) -> bool {
            let _entered = debug_span!("windowShouldClose:").entered();
            self.queue_event(WindowEvent::CloseRequested);
            false
        }

        #[unsafe(method(windowWillClose:))]
        fn window_will_close(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowWillClose:").entered();
            // `setDelegate:` retains the previous value and then autoreleases it
            autoreleasepool(|_| {
                // Since El Capitan, we need to be careful that delegate methods can't
                // be called after the window closes.
                self.window().setDelegate(None);
            });
            self.queue_event(WindowEvent::Destroyed);
        }

        #[unsafe(method(windowDidResize:))]
        fn window_did_resize(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidResize:").entered();
            // NOTE: WindowEvent::SurfaceResized is reported using NSViewFrameDidChangeNotification.
            self.emit_move_event();
            // `windowDidMove:` isn't triggered when a move is part of a resize (e.g. dragging the
            // top or left edge), so anchored children need repositioning here too.
            self.reposition_child_windows();
        }

        #[unsafe(method(windowWillStartLiveResize:))]
        fn window_will_start_live_resize(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowWillStartLiveResize:").entered();

            let increments = self.ivars().surface_resize_increments.get();
            self.set_resize_increments_inner(increments);
        }

        #[unsafe(method(windowDidEndLiveResize:))]
        fn window_did_end_live_resize(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidEndLiveResize:").entered();
            self.set_resize_increments_inner(NSSize::new(1., 1.));
        }

        // This won't be triggered if the move was part of a resize.
        #[unsafe(method(windowDidMove:))]
        fn window_did_move(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidMove:").entered();
            self.emit_move_event();
            self.reposition_child_windows();
        }

        #[unsafe(method(windowDidChangeBackingProperties:))]
        fn window_did_change_backing_properties(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidChangeBackingProperties:").entered();
            let scale_factor = self.scale_factor();
            if scale_factor == self.ivars().previous_scale_factor.get() {
                return;
            };
            self.ivars().previous_scale_factor.set(scale_factor);

            let mtm = MainThreadMarker::from(self);
            let this = self.retain();
            MainRunLoop::get(mtm).queue_closure(move || {
                this.handle_scale_factor_changed(scale_factor);
            });
        }

        #[unsafe(method(windowDidBecomeKey:))]
        fn window_did_become_key(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidBecomeKey:").entered();
            // TODO: center the cursor if the window had mouse grab when it
            // lost focus
            self.queue_event(WindowEvent::Focused(true));
        }

        #[unsafe(method(windowDidResignKey:))]
        fn window_did_resign_key(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidResignKey:").entered();
            // It happens rather often, e.g. when the user is Cmd+Tabbing, that the
            // NSWindowDelegate will receive a didResignKey event despite no event
            // being received when the modifiers are released. This is because
            // flagsChanged events are received by the NSView instead of the
            // NSWindowDelegate, and as a result a tracked modifiers state can quite
            // easily fall out of synchrony with reality. This requires us to emit
            // a synthetic ModifiersChanged event when we lose focus.
            self.view().reset_modifiers();

            self.queue_event(WindowEvent::Focused(false));
        }

        /// Invoked when before enter fullscreen
        #[unsafe(method(windowWillEnterFullScreen:))]
        fn window_will_enter_fullscreen(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowWillEnterFullScreen:").entered();

            self.ivars().maximized.set(self.is_zoomed());
            let mut fullscreen = self.ivars().fullscreen.borrow_mut();
            match &*fullscreen {
                // Exclusive mode sets the state in `set_fullscreen` as the user
                // can't enter exclusive mode by other means (like the
                // fullscreen button on the window decorations)
                Some(Fullscreen::Exclusive(..)) => (),
                // `window_will_enter_fullscreen` was triggered and we're already
                // in fullscreen, so we must've reached here by `set_fullscreen`
                // as it updates the state
                Some(Fullscreen::Borderless(_)) => (),
                Some(_) => (),
                // Otherwise, we must've reached fullscreen by the user clicking
                // on the green fullscreen button. Update state!
                None => {
                    let current_monitor = self
                        .current_monitor_inner()
                        .map(|monitor| CoreMonitorHandle(Arc::new(monitor)));
                    *fullscreen = Some(Fullscreen::Borderless(current_monitor));
                },
            }
            self.ivars().in_fullscreen_transition.set(true);
        }

        /// Invoked when before exit fullscreen
        #[unsafe(method(windowWillExitFullScreen:))]
        fn window_will_exit_fullscreen(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowWillExitFullScreen:").entered();

            self.ivars().in_fullscreen_transition.set(true);
        }

        #[unsafe(method(window:willUseFullScreenPresentationOptions:))]
        fn window_will_use_fullscreen_presentation_options(
            &self,
            _: Option<&AnyObject>,
            proposed_options: NSApplicationPresentationOptions,
        ) -> NSApplicationPresentationOptions {
            let _entered = debug_span!("window:willUseFullScreenPresentationOptions:").entered();
            // Generally, games will want to disable the menu bar and the dock. Ideally,
            // this would be configurable by the user. Unfortunately because of our
            // `CGShieldingWindowLevel() + 1` hack (see `set_fullscreen`), our window is
            // placed on top of the menu bar in exclusive fullscreen mode. This looks
            // broken so we always disable the menu bar in exclusive fullscreen. We may
            // still want to make this configurable for borderless fullscreen. Right now
            // we don't, for consistency. If we do, it should be documented that the
            // user-provided options are ignored in exclusive fullscreen.
            let mut options = proposed_options;
            let fullscreen = self.ivars().fullscreen.borrow();
            if let Some(Fullscreen::Exclusive(..)) = &*fullscreen {
                options = NSApplicationPresentationOptions::FullScreen
                    | NSApplicationPresentationOptions::HideDock
                    | NSApplicationPresentationOptions::HideMenuBar;
            }

            options
        }

        /// Invoked when entered fullscreen
        #[unsafe(method(windowDidEnterFullScreen:))]
        fn window_did_enter_fullscreen(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidEnterFullScreen:").entered();
            self.ivars().initial_fullscreen.set(false);
            self.ivars().in_fullscreen_transition.set(false);
            if let Some(target_fullscreen) = self.ivars().target_fullscreen.take() {
                self.set_fullscreen(target_fullscreen);
            }
        }

        /// Invoked when exited fullscreen
        #[unsafe(method(windowDidExitFullScreen:))]
        fn window_did_exit_fullscreen(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidExitFullScreen:").entered();

            self.restore_state_from_fullscreen();
            self.ivars().in_fullscreen_transition.set(false);
            if let Some(target_fullscreen) = self.ivars().target_fullscreen.take() {
                self.set_fullscreen(target_fullscreen);
            }
        }

        /// Invoked when fail to enter fullscreen
        ///
        /// When this window launch from a fullscreen app (e.g. launch from VS Code
        /// terminal), it creates a new virtual desktop and a transition animation.
        /// This animation takes one second and cannot be disable without
        /// elevated privileges. In this animation time, all toggleFullscreen events
        /// will be failed. In this implementation, we will try again by using
        /// performSelector:withObject:afterDelay: until window_did_enter_fullscreen.
        /// It should be fine as we only do this at initialization (i.e with_fullscreen
        /// was set).
        ///
        /// From Apple doc:
        /// In some cases, the transition to enter full-screen mode can fail,
        /// due to being in the midst of handling some other animation or user gesture.
        /// This method indicates that there was an error, and you should clean up any
        /// work you may have done to prepare to enter full-screen mode.
        #[unsafe(method(windowDidFailToEnterFullScreen:))]
        fn window_did_fail_to_enter_fullscreen(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidFailToEnterFullScreen:").entered();
            self.ivars().in_fullscreen_transition.set(false);
            self.ivars().target_fullscreen.replace(None);
            if self.ivars().initial_fullscreen.get() {
                unsafe {
                    self.window().performSelector_withObject_afterDelay(
                        sel!(toggleFullScreen:),
                        None,
                        0.5,
                    )
                };
            } else {
                self.restore_state_from_fullscreen();
            }
        }

        // Invoked when the occlusion state of the window changes
        #[unsafe(method(windowDidChangeOcclusionState:))]
        fn window_did_change_occlusion_state(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidChangeOcclusionState:").entered();
            let visible = self.window().occlusionState().contains(NSWindowOcclusionState::Visible);
            self.queue_event(WindowEvent::Occluded(!visible));

            // We do this here rather than in `window:willUseFullScreenPresentationOptions`
            // because doing it there leaves the menu bar interactable despite being hidden.
            // Moving it here produces the most consistent results.
            if self.is_borderless_game()
                && matches!(*self.ivars().fullscreen.borrow(), Some(Fullscreen::Borderless(_)))
            {
                let mtm = MainThreadMarker::from(self);
                let app = NSApplication::sharedApplication(mtm);
                app.setPresentationOptions(
                    NSApplicationPresentationOptions::HideDock
                        | NSApplicationPresentationOptions::HideMenuBar,
                );
            }
        }

        #[unsafe(method(windowDidChangeScreen:))]
        fn window_did_change_screen(&self, _: Option<&AnyObject>) {
            let _entered = debug_span!("windowDidChangeScreen:").entered();
            let is_simple_fullscreen = self.ivars().is_simple_fullscreen.get();
            if is_simple_fullscreen {
                if let Some(screen) = self.window().screen() {
                    self.window().setFrame_display(screen.frame(), true);
                }
            }
        }
    }

    unsafe impl NSDraggingSource for WindowDelegate {
        #[unsafe(method(draggingSession:sourceOperationMaskForDraggingContext:))]
        fn dragging_session_source_operation_mask(
            &self,
            _: &NSDraggingSession,
            _: NSDraggingContext,
        ) -> NSDragOperation {
            self.view().drag_operations()
        }

        #[unsafe(method(draggingSession:endedAtPoint:operation:))]
        fn dragging_session_ended_at_point(
            &self,
            session: &NSDraggingSession,
            _: NSPoint,
            operation: NSDragOperation,
        ) {
            let id = DataTransferId::from_raw(session.draggingSequenceNumber() as i64);
            if operation == NSDragOperation::None {
                self.queue_event(WindowEvent::OutgoingDragCanceled { id });
            } else {
                self.queue_event(WindowEvent::OutgoingDragDropped {
                    id,
                    action: ns_drag_operation_to_dnd_action(operation),
                });
            }

            self.view().clear_dragging_session(session);
        }
    }

    unsafe impl NSDraggingDestination for WindowDelegate {
        /// Invoked when the dragged image enters destination bounds or frame
        #[unsafe(method(draggingEntered:))]
        fn dragging_entered(&self, sender: &ProtocolObject<dyn NSDraggingInfo>) -> NSDragOperation {
            let _entered = debug_span!("draggingEntered:").entered();

            let pb =
                MainThreadBound::new(sender.draggingPasteboard(), MainThreadMarker::new().unwrap());

            let dl = sender.draggingLocation();
            let dl = self.view().convertPoint_fromView(dl, None);
            let position =
                LogicalPosition::<f64>::from((dl.x, dl.y)).to_physical(self.scale_factor());

            let window_id = self.id();

            let vars = self.ivars();

            let source_operations = sender.draggingSourceOperationMask();

            let transfer_id = DataTransferId::from_raw(sender.draggingSequenceNumber() as i64);
            vars.app_state.pasteboards().insert(transfer_id, &pb, window_id);

            vars.app_state
                .drag_state()
                .replace(Some(DragState { id: transfer_id, valid_actions: vec![] }));

            self.queue_event(WindowEvent::DragEntered {
                id: transfer_id,
                position: Some(position),
            });

            let drag_state = vars.app_state.drag_state().borrow();

            drag_state
                .as_ref()
                .and_then(|drag_state| {
                    preferred_drag_operation(source_operations, &drag_state.valid_actions)
                })
                .map(dnd_action_to_ns_drag_operation)
                .unwrap_or(NSDragOperation::empty())
        }

        #[unsafe(method(wantsPeriodicDraggingUpdates))]
        fn wants_periodic_dragging_updates(&self) -> bool {
            let _entered = debug_span!("wantsPeriodicDraggingUpdates:").entered();
            true
        }

        /// Invoked periodically as the image is held within the destination area, allowing
        /// modification of the dragging operation or mouse-pointer position.
        #[unsafe(method(draggingUpdated:))]
        fn dragging_updated(&self, sender: &ProtocolObject<dyn NSDraggingInfo>) -> NSDragOperation {
            let _entered = debug_span!("draggingUpdated:").entered();

            let vars = self.ivars();

            let Some(transfer_id) =
                vars.app_state.drag_state().borrow().as_ref().map(|state| state.id)
            else {
                return NSDragOperation::empty();
            };

            let pb =
                MainThreadBound::new(sender.draggingPasteboard(), MainThreadMarker::new().unwrap());

            let source_operations = sender.draggingSourceOperationMask();

            vars.app_state.pasteboards().set_pasteboard(transfer_id, &pb);

            let dl = sender.draggingLocation();
            let dl = self.view().convertPoint_fromView(dl, None);
            let position =
                LogicalPosition::<f64>::from((dl.x, dl.y)).to_physical(self.scale_factor());

            let proposed_action = vars.app_state.proposed_drag_action(source_operations);

            self.queue_event(WindowEvent::DragPosition {
                id: transfer_id,
                position,
                proposed_action,
            });

            let drag_state = vars.app_state.drag_state().borrow();

            drag_state
                .as_ref()
                .and_then(|drag_state| {
                    preferred_drag_operation(source_operations, &drag_state.valid_actions)
                })
                .map(dnd_action_to_ns_drag_operation)
                .unwrap_or(NSDragOperation::empty())
        }

        /// Invoked when the image is released
        #[unsafe(method(prepareForDragOperation:))]
        fn prepare_for_drag_operation(&self, _sender: &NSObject) -> bool {
            let _entered = debug_span!("prepareForDragOperation:").entered();
            true
        }

        /// Invoked after the released image has been removed from the screen
        #[unsafe(method(performDragOperation:))]
        fn perform_drag_operation(&self, sender: &ProtocolObject<dyn NSDraggingInfo>) -> bool {
            let _entered = debug_span!("performDragOperation:").entered();

            let vars = self.ivars();

            let Some(transfer_id) =
                vars.app_state.drag_state().borrow().as_ref().map(|state| state.id)
            else {
                return false.into();
            };

            let pb =
                MainThreadBound::new(sender.draggingPasteboard(), MainThreadMarker::new().unwrap());

            let source_operations = sender.draggingSourceOperationMask();
            // let operations = ns_drag_operation_to_dnd_actions(source_operations);

            vars.app_state.pasteboards().set_pasteboard(transfer_id, &pb);

            let dl = sender.draggingLocation();
            let dl = self.view().convertPoint_fromView(dl, None);
            let position =
                LogicalPosition::<f64>::from((dl.x, dl.y)).to_physical(self.scale_factor());

            let proposed_action = vars.app_state.proposed_drag_action(source_operations);

            self.queue_event(WindowEvent::DragPosition {
                id: transfer_id,
                position,
                proposed_action,
            });

            // Check again, in case the application updated
            let proposed_action = vars.app_state.proposed_drag_action(source_operations);

            self.queue_event(WindowEvent::DragDropped { id: transfer_id, proposed_action });

            // We assume that if the OS has sent `perform_drag_operation`, that the drag succeeded.
            // We may want to extend this API in the future to allow signalling that the final drop
            // failed.
            true
        }

        /// Invoked when the dragging operation is complete
        #[unsafe(method(concludeDragOperation:))]
        fn conclude_drag_operation(&self, _sender: Option<&NSObject>) {
            let _entered = debug_span!("concludeDragOperation:").entered();
            let vars = self.ivars();

            vars.app_state.pasteboards().remove_deloaded_pasteboards();
            vars.app_state.drag_state().take();
        }

        /// Invoked when the dragging operation is cancelled
        #[unsafe(method(draggingExited:))]
        fn dragging_exited(&self, sender: Option<&ProtocolObject<dyn NSDraggingInfo>>) {
            let _entered = debug_span!("draggingExited:").entered();

            let vars = self.ivars();

            let Some(transfer_id) =
                vars.app_state.drag_state().borrow().as_ref().map(|state| state.id)
            else {
                return;
            };

            if let Some(sender) = sender {
                let pb = MainThreadBound::new(
                    sender.draggingPasteboard(),
                    MainThreadMarker::new().unwrap(),
                );
                vars.app_state.pasteboards().set_pasteboard(transfer_id, &pb);

                let dl = sender.draggingLocation();
                let dl = self.view().convertPoint_fromView(dl, None);
                let position =
                    LogicalPosition::<f64>::from((dl.x, dl.y)).to_physical(self.scale_factor());

                let source_operations = sender.draggingSourceOperationMask();
                let proposed_action = vars.app_state.proposed_drag_action(source_operations);

                self.queue_event(WindowEvent::DragPosition {
                    id: transfer_id,
                    position,
                    proposed_action,
                });
            }

            self.queue_event(WindowEvent::DragLeft { id: transfer_id });

            vars.app_state.drag_state().take();
        }
    }

    /// Key-Value Observing
    impl WindowDelegate {
        #[unsafe(method(observeValueForKeyPath:ofObject:change:context:))]
        fn observe_value(
            &self,
            key_path: Option<&NSString>,
            _object: Option<&AnyObject>,
            change: Option<&NSDictionary<NSKeyValueChangeKey, AnyObject>>,
            _context: *mut c_void,
        ) {
            let _entered = debug_span!("observeValueForKeyPath:ofObject:change:context:").entered();
            // NOTE: We don't _really_ need to check the key path, as there should only be one, but
            // in the future we might want to observe other key paths.
            if key_path == Some(ns_string!("effectiveAppearance")) {
                let change = change.expect(
                    "requested a change dictionary in `addObserver`, but none was provided",
                );
                let old = change
                    .objectForKey(unsafe { NSKeyValueChangeOldKey })
                    .expect("requested change dictionary did not contain `NSKeyValueChangeOldKey`");
                let new = change
                    .objectForKey(unsafe { NSKeyValueChangeNewKey })
                    .expect("requested change dictionary did not contain `NSKeyValueChangeNewKey`");

                // The value of `effectiveAppearance` is `NSAppearance`
                let old = old.downcast::<NSAppearance>().unwrap();
                let new = new.downcast::<NSAppearance>().unwrap();

                trace!(old = %old.name(), new = %new.name(), "effectiveAppearance changed");

                // Ignore the change if the window's theme is customized by the user (since in that
                // case the `effectiveAppearance` is only emitted upon said customization, and then
                // it's triggered directly by a user action, and we don't want to emit the event).
                if self.window().appearance().is_some() {
                    return;
                }

                let old = appearance_to_theme(&old);
                let new = appearance_to_theme(&new);
                // Check that the theme changed in Winit's terms (the theme might have changed on
                // other parameters, such as level of contrast, but the event should not be emitted
                // in those cases).
                if old == new {
                    return;
                }

                self.queue_event(WindowEvent::ThemeChanged(new));
            } else {
                panic!("unknown observed keypath {key_path:?}");
            }
        }
    }
);

impl Drop for WindowDelegate {
    fn drop(&mut self) {
        unsafe { self.window().removeObserver_forKeyPath(self, ns_string!("effectiveAppearance")) };
    }
}

fn new_window(
    app_state: &Rc<AppState>,
    attrs: &WindowAttributes,
    macos_attrs: &WindowAttributesMacOS,
    anchored: bool,
    mtm: MainThreadMarker,
) -> Option<(Retained<NSWindow>, Retained<WinitView>)> {
    autoreleasepool(|_| {
        let screen = match attrs.fullscreen.clone() {
            Some(Fullscreen::Borderless(Some(monitor)))
            | Some(Fullscreen::Exclusive(monitor, _)) => {
                let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
                monitor.ns_screen(mtm).or_else(|| NSScreen::mainScreen(mtm))
            },
            Some(Fullscreen::Borderless(None)) => NSScreen::mainScreen(mtm),
            Some(_) => NSScreen::mainScreen(mtm),
            None => None,
        };
        let frame = match &screen {
            Some(screen) => screen.frame(),
            None => {
                let scale_factor = NSScreen::mainScreen(mtm)
                    .map(|screen| screen.backingScaleFactor() as f64)
                    .unwrap_or(1.0);
                let size = match attrs.surface_size {
                    Some(size) => {
                        let size = size.to_logical(scale_factor);
                        NSSize::new(size.width, size.height)
                    },
                    None => NSSize::new(800.0, 600.0),
                };
                let position = match attrs.position {
                    // An anchored window's position is parent-relative; it's applied in
                    // `WindowDelegate::new` (after the delegate exists) via the shared
                    // translation in `set_outer_position`. A parentless anchored window can't be
                    // positioned that way, so it falls through to the same handling as a
                    // non-anchored window below.
                    _ if anchored && attrs.parent_window().is_some() => NSPoint::new(0.0, 0.0),
                    Some(position) => {
                        let position = position.to_logical(scale_factor);
                        flip_window_screen_coordinates(NSRect::new(
                            NSPoint::new(position.x, position.y),
                            size,
                        ))
                    },
                    // This value is ignored by calling win.center() below
                    None => NSPoint::new(0.0, 0.0),
                };
                NSRect::new(position, size)
            },
        };

        let mut masks = if (!attrs.decorations && screen.is_none()) || macos_attrs.titlebar_hidden {
            // Resizable without a titlebar or borders
            // if decorations is set to false, ignore pl_attrs
            //
            // if the titlebar is hidden, ignore other pl_attrs
            NSWindowStyleMask::Borderless
                | NSWindowStyleMask::Resizable
                | NSWindowStyleMask::Miniaturizable
        } else {
            // default case, resizable window with titlebar and titlebar buttons
            NSWindowStyleMask::Closable
                | NSWindowStyleMask::Miniaturizable
                | NSWindowStyleMask::Resizable
                | NSWindowStyleMask::Titled
        };

        if !attrs.resizable {
            masks &= !NSWindowStyleMask::Resizable;
        }

        if !attrs.enabled_buttons.contains(WindowButtons::MINIMIZE) {
            masks &= !NSWindowStyleMask::Miniaturizable;
        }

        if !attrs.enabled_buttons.contains(WindowButtons::CLOSE) {
            masks &= !NSWindowStyleMask::Closable;
        }

        if macos_attrs.fullsize_content_view {
            // NOTE: If we decide to add an option to change this at runtime, we must emit a
            // `SurfaceResized` event to let applications know that the safe area changed.
            //
            // An alternative would be to add a `WindowEvent::SafeAreaChanged` event, this could be
            // done with an observer on `safeAreaRect` / `contentLayoutRect`, see:
            // <https://github.com/rust-windowing/winit/issues/3911>
            masks |= NSWindowStyleMask::FullSizeContentView;
        }

        // NOTE: This should only be created after the application has started launching,
        // (`applicationWillFinishLaunching:` at the earliest), otherwise you'll run into very
        // confusing issues with the window not being properly activated.
        //
        // Winit ensures this by not allowing access to `ActiveEventLoop` before handling events.
        // Panels (including popups) are non-activating so they don't steal key focus
        // from their parent (matching menu/combobox semantics).
        let window: Retained<NSWindow> = if macos_attrs.panel {
            masks |= NSWindowStyleMask::NonactivatingPanel;

            let window: Option<Retained<WinitPanel>> = unsafe {
                msg_send![
                    super(mtm.alloc().set_ivars(())),
                    initWithContentRect: frame,
                    styleMask: masks,
                    backing: NSBackingStoreType::Buffered,
                    defer: false,
                ]
            };

            window?.as_super().as_super().retain()
        } else {
            let window: Option<Retained<WinitWindow>> = unsafe {
                msg_send![
                    super(mtm.alloc().set_ivars(())),
                    initWithContentRect: frame,
                    styleMask: masks,
                    backing: NSBackingStoreType::Buffered,
                    defer: false,
                ]
            };

            window?.as_super().retain()
        };

        // It is very important for correct memory management that we
        // disable the extra release that would otherwise happen when
        // calling `close` on the window.
        unsafe { window.setReleasedWhenClosed(false) };

        window.setTitle(&NSString::from_str(&attrs.title));
        window.setAcceptsMouseMovedEvents(true);

        if let Some(identifier) = &macos_attrs.tabbing_identifier {
            window.setTabbingIdentifier(&NSString::from_str(identifier));
            window.setTabbingMode(NSWindowTabbingMode::Preferred);
        }

        if attrs.content_protected {
            window.setSharingType(NSWindowSharingType::None);
        }

        if macos_attrs.titlebar_transparent {
            window.setTitlebarAppearsTransparent(true);
        }
        if macos_attrs.title_hidden {
            window.setTitleVisibility(NSWindowTitleVisibility::Hidden);
        }
        if macos_attrs.titlebar_buttons_hidden {
            for titlebar_button in &[
                #[allow(deprecated)]
                objc2_app_kit::NSWindowFullScreenButton,
                NSWindowButton::MiniaturizeButton,
                NSWindowButton::CloseButton,
                NSWindowButton::ZoomButton,
            ] {
                if let Some(button) = window.standardWindowButton(*titlebar_button) {
                    button.setHidden(true);
                }
            }
        }
        if macos_attrs.movable_by_window_background {
            window.setMovableByWindowBackground(true);
        }
        if macos_attrs.unified_titlebar {
            // The toolbar style is ignored if there is no toolbar, so it is
            // necessary to add one.
            window.setToolbar(Some(&NSToolbar::new(mtm)));
            window.setToolbarStyle(NSWindowToolbarStyle::Unified);
        }

        if !attrs.enabled_buttons.contains(WindowButtons::MAXIMIZE) {
            if let Some(button) = window.standardWindowButton(NSWindowButton::ZoomButton) {
                button.setEnabled(false);
            }
        }

        if !macos_attrs.has_shadow {
            window.setHasShadow(false);
        }
        if macos_attrs.fullscreen_auxiliary {
            // This must happen before the window is ordered on screen (below, and in
            // `WindowDelegate::new`), so that showing the window doesn't make macOS
            // switch away from an active fullscreen Space or attempt Split View tiling.
            window.setCollectionBehavior(
                window.collectionBehavior() | NSWindowCollectionBehavior::FullScreenAuxiliary,
            );
        }
        // Center window if the position is not set or it doesn't have any parent
        if attrs.position.is_none() && !(anchored && attrs.parent_window().is_some()) {
            window.center();
        }

        let view = WinitView::new(app_state, macos_attrs.option_as_alt, mtm);

        // The default value of `setWantsBestResolutionOpenGLSurface:` was `false` until
        // macos 10.14 and `true` after 10.15, we should set it to `YES` or `NO` to avoid
        // always the default system value in favour of the user's code
        #[allow(deprecated)]
        view.setWantsBestResolutionOpenGLSurface(!macos_attrs.disallow_hidpi);

        // On Mojave, views automatically become layer-backed shortly after being added to
        // a window. Changing the layer-backedness of a view breaks the association between
        // the view and its associated OpenGL context. To work around this, on Mojave we
        // explicitly make the view layer-backed up front so that AppKit doesn't do it
        // itself and break the association with its context.
        if unsafe { NSAppKitVersionNumber }.floor() > NSAppKitVersionNumber10_12 {
            view.setWantsLayer(true);
        }

        let content_view = NSView::new(mtm);
        window.setContentView(Some(&content_view));

        view.setFrame(content_view.bounds());
        view.setAutoresizingMask(
            NSAutoresizingMaskOptions::ViewWidthSizable
                | NSAutoresizingMaskOptions::ViewHeightSizable,
        );
        content_view.addSubview(&view);

        // Configure the new view as the "key view" for the window
        window.setInitialFirstResponder(Some(&view));

        // Configure the view to send notifications whenever its frame rectangle changes.
        //
        // We explicitly do this _after_ adding the view to the window, to
        // avoid a resize event when creating the window.
        view.setPostsFrameChangedNotifications(true);
        // `setPostsFrameChangedNotifications` posts the notification immediately, so register the
        // observer _after_, again so that the event isn't triggered initially.
        let notification_center = NSNotificationCenter::defaultCenter();
        unsafe {
            notification_center.addObserver_selector_name_object(
                &view,
                sel!(viewFrameDidChangeNotification:),
                Some(NSViewFrameDidChangeNotification),
                Some(&view),
            )
        }

        if attrs.transparent {
            window.setOpaque(false);
            // See `set_transparent` for details on why we do this.
            window.setBackgroundColor(Some(&NSColor::clearColor()));
        }

        Some((window, view))
    })
}

impl WindowDelegate {
    pub(super) fn new(
        app_state: &Rc<AppState>,
        mut attrs: WindowAttributes,
        mtm: MainThreadMarker,
    ) -> Result<Retained<Self>, RequestError> {
        let mut macos_attrs = attrs
            .platform
            .take()
            .and_then(|attrs| attrs.cast::<WindowAttributesMacOS>().ok())
            .unwrap_or_default();

        let window_type = attrs.window_type();
        let is_popup = matches!(window_type, WindowType::Popup);
        let anchored = is_popup || attrs.positioner.is_some();
        if is_popup {
            // A popup is an undecorated, non-activating panel with no titlebar buttons. Model it
            // as such so it flows through the existing borderless + panel paths in `new_window`
            // instead of needing dedicated branches.
            attrs.decorations = false;
            attrs.enabled_buttons = WindowButtons::empty();
            // Unless grab_keyboard is requested, use a non-activating panel so the popup doesn't
            // steal keyboard focus from the parent window.
            if !attrs.active {
                macos_attrs.panel = true;
            }
        }

        let (window, view) = new_window(app_state, &attrs, &macos_attrs, anchored, mtm)
            .ok_or_else(|| os_error!("couldn't create `NSWindow`"))?;

        match attrs.parent_window() {
            Some(rwh_06::RawWindowHandle::AppKit(handle)) => {
                // SAFETY: Caller ensures the pointer is valid or NULL
                // Unwrap is fine, since the pointer comes from `NonNull`.
                let parent_view: Retained<NSView> =
                    unsafe { Retained::retain(handle.ns_view.as_ptr().cast()) }.unwrap();
                let parent = parent_view
                    .window()
                    .ok_or_else(|| os_error!("parent view should be installed in a window"))?;

                // SAFETY: We know that there are no parent -> child -> parent cycles since the only
                // place in `winit` where we allow making a window a child window is
                // right here, just after it's been created.
                unsafe { parent.addChildWindow_ordered(&window, NSWindowOrderingMode::Above) };
            },
            Some(raw) => panic!("invalid raw window handle {raw:?} on macOS"),
            None if is_popup => {
                return Err(RequestError::NotSupported(NotSupportedError::new(
                    "a popup window requires a parent window",
                )));
            },
            None => (),
        }

        let surface_resize_increments = match attrs
            .surface_resize_increments
            .map(|i| i.to_logical(window.backingScaleFactor() as _))
        {
            Some(LogicalSize { width, height }) if width >= 1. && height >= 1. => {
                NSSize::new(width, height)
            },
            _ => NSSize::new(1., 1.),
        };

        let scale_factor = window.backingScaleFactor() as _;

        if let Some(appearance) = theme_to_appearance(attrs.preferred_theme) {
            window.setAppearance(Some(&appearance));
        }

        let delegate = mtm.alloc().set_ivars(State {
            app_state: Rc::clone(app_state),
            window: window.retain(),
            view,
            #[cfg(not(feature = "private-apple-apis"))]
            blur_view: RefCell::new(None),
            blur_material: Cell::new(macos_attrs.blur_material),
            previous_position: Cell::new(flip_window_screen_coordinates(window.frame())),
            previous_scale_factor: Cell::new(scale_factor),
            surface_resize_increments: Cell::new(surface_resize_increments),
            decorations: Cell::new(attrs.decorations),
            resizable: Cell::new(attrs.resizable),
            maximized: Cell::new(attrs.maximized),
            save_presentation_opts: Cell::new(None),
            initial_fullscreen: Cell::new(attrs.fullscreen.is_some()),
            fullscreen: RefCell::new(None),
            target_fullscreen: RefCell::new(None),
            in_fullscreen_transition: Cell::new(false),
            standard_frame: Cell::new(None),
            is_simple_fullscreen: Cell::new(false),
            saved_style: Cell::new(None),
            is_borderless_game: Cell::new(macos_attrs.borderless_game),
            window_type,
            anchored,
            positioner: RefCell::new(attrs.positioner.unwrap_or_default()),
        });
        let delegate: Retained<WindowDelegate> = unsafe { msg_send![super(delegate), init] };

        window.setDelegate(Some(ProtocolObject::from_ref(&*delegate)));

        let drag_types = unsafe {
            // Advertize support for the set of types which correspond to variants of `TypeHint`.
            // If the user wants to support other pasteboard types which don't have a cross-platform
            // equivalent, they can downcast the window and manually call `registerForDraggedTypes`
            // themselves.
            NSArray::from_slice(&[
                NSPasteboardTypeFileURL,
                NSPasteboardTypeHTML,
                NSPasteboardTypePNG,
                NSPasteboardTypeSound,
                NSPasteboardTypeString,
                NSPasteboardTypeTIFF,
            ])
        };
        window.registerForDraggedTypes(&drag_types);

        // Listen for theme change event.
        //
        // SAFETY: The observer is un-registered in the `Drop` of the delegate.
        unsafe {
            window.addObserver_forKeyPath_options_context(
                &delegate,
                ns_string!("effectiveAppearance"),
                NSKeyValueObservingOptions::New | NSKeyValueObservingOptions::Old,
                ptr::null_mut(),
            )
        };

        if attrs.blur {
            delegate.set_blur(attrs.blur);
        }

        if let Some(dim) = attrs.min_surface_size {
            delegate.set_min_surface_size(Some(dim));
        }
        if let Some(dim) = attrs.max_surface_size {
            delegate.set_max_surface_size(Some(dim));
        }

        delegate.set_window_level(attrs.window_level);

        // An anchored window's position is relative to the parent window, and the parent is
        // only attached above, so apply the (translated) position now. Default to the parent's
        // content top-left when no position was given.
        if anchored {
            let position = attrs.position.unwrap_or_else(|| LogicalPosition::new(0.0, 0.0).into());
            delegate.set_outer_position(position);
        }

        delegate.set_cursor(attrs.cursor);

        // Set fullscreen mode after we setup everything
        delegate.set_fullscreen(attrs.fullscreen);

        // Setting the window as key has to happen *after* we set the fullscreen
        // state, since otherwise we'll briefly see the window at normal size
        // before it transitions.
        if attrs.visible {
            if attrs.active {
                // Tightly linked with `app_state::window_activation_hack`
                window.makeKeyAndOrderFront(None);
            } else {
                window.orderFront(None);
            }
        }

        if attrs.maximized {
            delegate.set_maximized(attrs.maximized);
        }

        Ok(delegate)
    }

    pub(super) fn view(&self) -> Retained<WinitView> {
        self.ivars().view.clone()
    }

    #[track_caller]
    pub(super) fn window(&self) -> &NSWindow {
        &self.ivars().window
    }

    #[track_caller]
    pub(crate) fn id(&self) -> WindowId {
        window_id(self.window())
    }

    pub(crate) fn queue_event(&self, event: WindowEvent) {
        let window_id = window_id(self.window());
        self.ivars().app_state.maybe_queue_with_handler(move |app, event_loop| {
            app.window_event(event_loop, window_id, event);
        });
    }

    fn defer_if_handling_event(&self, f: impl FnOnce(Retained<Self>) + 'static) -> bool {
        // AppKit state transitions such as zoom/fullscreen can synchronously run resize/display
        // callbacks. Starting them from inside a winit event callback prevents those callbacks
        // from being delivered immediately, so defer the transition to the next run-loop turn.
        if !self.ivars().app_state.is_handling_event() {
            return false;
        }

        let mtm = MainThreadMarker::from(self);
        let this = self.retain();
        MainRunLoop::get(mtm).queue_closure(move || f(this));
        true
    }

    fn handle_scale_factor_changed(&self, scale_factor: CGFloat) {
        let window = self.window();

        let suggested_size = self.view().surface_size();
        let new_surface_size = Arc::new(Mutex::new(suggested_size));
        self.queue_event(WindowEvent::ScaleFactorChanged {
            scale_factor,
            surface_size_writer: SurfaceSizeWriter::new(Arc::downgrade(&new_surface_size)),
        });
        let physical_size = *new_surface_size.lock().unwrap();
        drop(new_surface_size);

        if physical_size != suggested_size {
            let logical_size = physical_size.to_logical(scale_factor);
            let size = NSSize::new(logical_size.width, logical_size.height);
            window.setContentSize(size);
        }
        self.view().surface_resized();
    }

    fn emit_move_event(&self) {
        let position = flip_window_screen_coordinates(self.window().frame());
        if self.ivars().previous_position.get() == position {
            return;
        }
        self.ivars().previous_position.set(position);

        let position =
            LogicalPosition::new(position.x, position.y).to_physical(self.scale_factor());
        self.queue_event(WindowEvent::Moved(position));
    }

    fn set_style_mask(&self, mask: NSWindowStyleMask) {
        self.window().setStyleMask(mask);
        // If we don't do this, key handling will break
        // (at least until the window is clicked again/etc.)
        let _ = self.window().makeFirstResponder(Some(&self.view()));
    }

    pub fn set_title(&self, title: &str) {
        self.window().setTitle(&NSString::from_str(title))
    }

    pub fn set_transparent(&self, transparent: bool) {
        // This is just a hint for Quartz, it doesn't actually speculate with window alpha.
        // Providing a wrong value here could result in visual artifacts, when the window is
        // transparent.
        self.window().setOpaque(!transparent);

        // AppKit draws the window with a background color by default, which is usually really
        // nice, but gets in the way when we want to allow the contents of the window to be
        // transparent, as in that case, the transparent contents will just be drawn on top of
        // the background color. As such, to allow the window to be transparent, we must also set
        // the background color to one with an empty alpha channel.
        let color =
            if transparent { NSColor::clearColor() } else { NSColor::windowBackgroundColor() };

        self.window().setBackgroundColor(Some(&color));
    }

    pub fn set_blur(&self, blur: bool) {
        #[cfg(feature = "private-apple-apis")]
        {
            #[link(name = "CoreGraphics", kind = "framework")]
            unsafe extern "C" {
                // Wildly used private APIs; Apple uses them for their Terminal.app.
                pub fn CGSMainConnectionID() -> *mut objc2::runtime::AnyObject;
                pub fn CGSSetWindowBackgroundBlurRadius(
                    connection_id: *mut objc2::runtime::AnyObject,
                    window_id: objc2_foundation::NSInteger,
                    radius: i64,
                ) -> i32;
            }

            // NOTE: in general we want to specify the blur radius, but the choice of 80
            // should be a reasonable default.
            let radius = if blur { 80 } else { 0 };
            let window_number = self.window().windowNumber();
            unsafe {
                CGSSetWindowBackgroundBlurRadius(CGSMainConnectionID(), window_number, radius)
            };
        }

        #[cfg(not(feature = "private-apple-apis"))]
        {
            if !blur {
                let installed = self.ivars().blur_view.borrow_mut().take();
                if let Some(installed) = installed {
                    installed.removeFromSuperview();
                }
                return;
            }

            if self.ivars().blur_view.borrow().is_some() {
                return;
            }

            let mtm = MainThreadMarker::from(self);
            let view = self.view();
            let content_view =
                self.window().contentView().expect("window always has a content view");

            let new_blur_view = NSVisualEffectView::new(mtm);
            new_blur_view.setBlendingMode(NSVisualEffectBlendingMode::BehindWindow);
            new_blur_view.setState(NSVisualEffectState::Active);
            if let Some(material) = ns_visual_effect_material(self.ivars().blur_material.get()) {
                new_blur_view.setMaterial(material);
            }
            new_blur_view.setFrame(content_view.bounds());
            new_blur_view.setAutoresizingMask(
                NSAutoresizingMaskOptions::ViewWidthSizable
                    | NSAutoresizingMaskOptions::ViewHeightSizable,
            );
            content_view.addSubview_positioned_relativeTo(
                &new_blur_view,
                NSWindowOrderingMode::Below,
                Some(&view),
            );

            *self.ivars().blur_view.borrow_mut() = Some(new_blur_view);
        }
    }

    pub fn set_visible(&self, visible: bool) {
        match visible {
            true => self.window().makeKeyAndOrderFront(None),
            false => self.window().orderOut(None),
        }
    }

    #[inline]
    pub fn is_visible(&self) -> Option<bool> {
        Some(self.window().isVisible())
    }

    pub fn request_redraw(&self) {
        self.ivars().app_state.queue_redraw(window_id(self.window()));
    }

    #[inline]
    pub fn pre_present_notify(&self) {}

    pub fn outer_position(&self) -> Result<PhysicalPosition<i32>, RequestError> {
        let position = flip_window_screen_coordinates(self.window().frame());
        let position = self
            .translate_anchored_position_to_parent(LogicalPosition::new(position.x, position.y));
        Ok(position.to_physical(self.scale_factor()))
    }

    pub fn surface_position(&self) -> PhysicalPosition<i32> {
        // The calculation here is a bit awkward because we've gotta reconcile the
        // different origins (Winit prefers top-left vs. NSWindow's bottom-left),
        // and I couldn't find a built-in way to do so.

        // The position of the window and the view, both in Winit screen coordinates.
        let window_position = flip_window_screen_coordinates(self.window().frame());
        let view_position = flip_window_screen_coordinates(
            self.window().contentRectForFrameRect(self.window().frame()),
        );

        // And use that to convert the view position to window coordinates.
        let surface_position =
            NSPoint::new(view_position.x - window_position.x, view_position.y - window_position.y);

        let logical = LogicalPosition::new(surface_position.x, surface_position.y);
        logical.to_physical(self.scale_factor())
    }

    pub fn set_outer_position(&self, position: Position) {
        let position = position.to_logical(self.scale_factor());
        let position = self.translate_anchored_position(position);
        let point = flip_window_screen_coordinates(NSRect::new(
            NSPoint::new(position.x, position.y),
            self.window().frame().size,
        ));
        self.window().setFrameOrigin(point);
    }

    /// Anchored windows receive their position relative to the top-left of the parent window's
    /// content area (matching the Win32 and Wayland backends). macOS positions windows
    /// in global screen coordinates, so add the parent content area's origin.
    fn translate_anchored_position(&self, position: LogicalPosition<f64>) -> LogicalPosition<f64> {
        if !self.ivars().anchored {
            return position;
        }
        let Some(parent) = self.window().parentWindow() else {
            return position;
        };
        let parent_origin =
            flip_window_screen_coordinates(parent.contentRectForFrameRect(parent.frame()));
        LogicalPosition::new(parent_origin.x + position.x, parent_origin.y + position.y)
    }

    /// Inverse of [`Self::translate_anchored_position`]. Anchored windows report their position
    /// relative to the top-left of the parent window's content area (matching the
    /// Win32 and Wayland backends), so subtract the parent content area's origin from
    /// the global screen coordinates. Non-anchored windows are returned unchanged.
    fn translate_anchored_position_to_parent(
        &self,
        position: LogicalPosition<f64>,
    ) -> LogicalPosition<f64> {
        if !self.ivars().anchored {
            return position;
        }
        let Some(parent) = self.window().parentWindow() else {
            return position;
        };
        let parent_origin =
            flip_window_screen_coordinates(parent.contentRectForFrameRect(parent.frame()));
        LogicalPosition::new(position.x - parent_origin.x, position.y - parent_origin.y)
    }

    /// The parent window's content area origin, in global (Winit, top-left/y-down) screen
    /// coordinates. `None` if this window isn't anchored, or it has no parent.
    pub fn parent_content_origin(&self) -> Option<LogicalPosition<f64>> {
        if !self.ivars().anchored {
            return None;
        }
        let parent = self.window().parentWindow()?;
        let origin = flip_window_screen_coordinates(parent.contentRectForFrameRect(parent.frame()));
        Some(LogicalPosition::new(origin.x, origin.y))
    }

    pub fn window_type(&self) -> WindowType {
        self.ivars().window_type
    }

    pub fn popup_positioner(&self) -> WindowPositioner {
        *self.ivars().positioner.borrow()
    }

    pub fn set_popup_positioner(&self, positioner: WindowPositioner) {
        *self.ivars().positioner.borrow_mut() = positioner;
        self.reposition();
    }

    /// Recomputes this window's position (and, if constrained, its size) from its positioner
    /// state, using [`winit_common::positioner::place_window`], and applies the result. No-op if
    /// this window isn't anchored. If it has no parent, the positioner is resolved relative to
    /// the screen instead of the parent's content area.
    pub(crate) fn reposition(&self) {
        if !self.ivars().anchored {
            return;
        }

        let positioner = *self.ivars().positioner.borrow();

        let parent_origin = self.parent_content_origin().unwrap_or_default();

        let Some(monitor) = self.current_monitor() else { return };
        // Clip to the monitor's work area rather than its full bounds, so anchored popups don't
        // get placed underneath the menu bar or the Dock.
        let Some((work_area_position, work_area_size)) = monitor.work_area() else { return };

        let scale_factor = self.scale_factor();

        // The anchor rect's position is relative to the parent's content area, and
        // `set_outer_position` re-adds the parent's screen origin for anchored windows (see
        // `translate_anchored_position`). To stay in the same coordinate space, the clip region
        // also needs to be expressed relative to the parent's content area.
        let work_area_position = work_area_position.to_logical::<f64>(scale_factor);
        let clip_position = LogicalPosition::new(
            work_area_position.x - parent_origin.x,
            work_area_position.y - parent_origin.y,
        );
        let clip_size = work_area_size.to_logical::<f64>(scale_factor);

        let current_outer_size = self.outer_size().to_logical::<f64>(scale_factor);

        let (origin, new_outer_size) =
            place_window(&positioner, scale_factor, current_outer_size, (clip_position, clip_size));

        self.set_outer_position(Position::Logical(origin));
        if new_outer_size != current_outer_size {
            // `place_window` positions the window by its outer/frame corner, so it operates on
            // the outer size; convert back to the surface (content) size that
            // `request_surface_size` expects, via AppKit's frame/content rect conversion.
            let frame = NSRect::new(
                NSPoint::new(0.0, 0.0),
                NSSize::new(new_outer_size.width, new_outer_size.height),
            );
            let content_size = self.window().contentRectForFrameRect(frame).size;
            let content_size = LogicalSize::new(content_size.width, content_size.height);
            let _ = self.request_surface_size(Size::Logical(content_size));
        }
    }

    /// Repositions any anchored children owned by this window. AppKit's `addChildWindow:ordered:`
    /// only manages ordering and visibility for child windows -- it doesn't keep their position
    /// in sync with the parent -- so this has to be done manually whenever this window moves.
    fn reposition_child_windows(&self) {
        let Some(children) = self.window().childWindows() else { return };
        for child in children.iter() {
            let Some(child_delegate) = child.delegate() else { continue };
            let Ok(child_delegate) = child_delegate.downcast::<WindowDelegate>() else { continue };
            if child_delegate.ivars().anchored {
                child_delegate.reposition();
            }
        }
    }

    #[inline]
    pub fn surface_size(&self) -> PhysicalSize<u32> {
        self.view().surface_size()
    }

    #[inline]
    pub fn outer_size(&self) -> PhysicalSize<u32> {
        let frame = self.window().frame();
        let logical = LogicalSize::new(frame.size.width, frame.size.height);
        logical.to_physical(self.scale_factor())
    }

    pub fn safe_area(&self) -> PhysicalInsets<u32> {
        // Only available on macOS 11.0
        let insets = if self.view().respondsToSelector(sel!(safeAreaInsets)) {
            // Includes NSWindowStyleMask::FullSizeContentView by default, and the notch because
            // we've set it up with `additionalSafeAreaInsets`.
            self.view().safeAreaInsets()
        } else {
            // If `safeAreaInsets` is not available, we'll have to do the calculation ourselves.

            let window_rect = self.window().convertRectFromScreen(
                self.window().contentRectForFrameRect(self.window().frame()),
            );
            // This includes NSWindowStyleMask::FullSizeContentView.
            let layout_rect = self.window().contentLayoutRect();

            // Calculate the insets from window coordinates in AppKit's coordinate system.
            NSEdgeInsets {
                top: (window_rect.size.height + window_rect.origin.y)
                    - (layout_rect.size.height + layout_rect.origin.y),
                left: layout_rect.origin.x - window_rect.origin.x,
                bottom: layout_rect.origin.y - window_rect.origin.y,
                right: (window_rect.size.width + window_rect.origin.x)
                    - (layout_rect.size.width + layout_rect.origin.x),
            }
        };
        let insets = LogicalInsets::new(insets.top, insets.left, insets.bottom, insets.right);
        insets.to_physical(self.scale_factor())
    }

    #[inline]
    pub fn request_surface_size(&self, size: Size) -> Option<PhysicalSize<u32>> {
        let scale_factor = self.scale_factor();
        let size = size.to_logical(scale_factor);
        self.window().setContentSize(NSSize::new(size.width, size.height));
        None
    }

    pub fn set_min_surface_size(&self, dimensions: Option<Size>) {
        let dimensions =
            dimensions.unwrap_or(Size::Logical(LogicalSize { width: 0.0, height: 0.0 }));
        let min_size = dimensions.to_logical::<CGFloat>(self.scale_factor());

        let min_size = NSSize::new(min_size.width, min_size.height);
        self.window().setContentMinSize(min_size);

        // If necessary, resize the window to match constraint
        let mut current_size = self.window().contentRectForFrameRect(self.window().frame()).size;
        if current_size.width < min_size.width {
            current_size.width = min_size.width;
        }
        if current_size.height < min_size.height {
            current_size.height = min_size.height;
        }
        self.window().setContentSize(current_size);
    }

    pub fn set_max_surface_size(&self, dimensions: Option<Size>) {
        let dimensions = dimensions.unwrap_or(Size::Logical(LogicalSize {
            width: f32::MAX as f64,
            height: f32::MAX as f64,
        }));
        let scale_factor = self.scale_factor();
        let max_size = dimensions.to_logical::<CGFloat>(scale_factor);

        let max_size = NSSize::new(max_size.width, max_size.height);
        self.window().setContentMaxSize(max_size);

        // If necessary, resize the window to match constraint
        let mut current_size = self.window().contentRectForFrameRect(self.window().frame()).size;
        if max_size.width < current_size.width {
            current_size.width = max_size.width;
        }
        if max_size.height < current_size.height {
            current_size.height = max_size.height;
        }
        self.window().setContentSize(current_size);
    }

    pub fn surface_resize_increments(&self) -> Option<PhysicalSize<u32>> {
        let increments = self.ivars().surface_resize_increments.get();
        let (w, h) = (increments.width, increments.height);
        if w > 1.0 || h > 1.0 {
            Some(LogicalSize::new(w, h).to_physical(self.scale_factor()))
        } else {
            None
        }
    }

    pub fn set_surface_resize_increments(&self, increments: Option<Size>) {
        // XXX the resize increments are only used during live resizes.
        self.ivars().surface_resize_increments.set(
            increments
                .map(|increments| {
                    let logical = increments.to_logical::<f64>(self.scale_factor());
                    NSSize::new(logical.width.max(1.0), logical.height.max(1.0))
                })
                .unwrap_or_else(|| NSSize::new(1.0, 1.0)),
        );
    }

    pub(crate) fn set_resize_increments_inner(&self, size: NSSize) {
        // It was concluded (#2411) that there is never a use-case for
        // "outer" resize increments, hence we set "inner" ones here.
        // ("outer" in macOS being just resizeIncrements, and "inner" - contentResizeIncrements)
        // This is consistent with X11 size hints behavior
        self.window().setContentResizeIncrements(size);
    }

    #[inline]
    pub fn set_resizable(&self, resizable: bool) {
        self.ivars().resizable.set(resizable);
        let fullscreen = self.ivars().fullscreen.borrow().is_some();
        if !fullscreen {
            let mut mask = self.window().styleMask();
            if resizable {
                mask |= NSWindowStyleMask::Resizable;
            } else {
                mask &= !NSWindowStyleMask::Resizable;
            }
            self.set_style_mask(mask);
        }
        // Otherwise, we don't change the mask until we exit fullscreen.
    }

    #[inline]
    pub fn is_resizable(&self) -> bool {
        self.window().isResizable()
    }

    #[inline]
    pub fn set_enabled_buttons(&self, buttons: WindowButtons) {
        let mut mask = self.window().styleMask();

        if buttons.contains(WindowButtons::CLOSE) {
            mask |= NSWindowStyleMask::Closable;
        } else {
            mask &= !NSWindowStyleMask::Closable;
        }

        if buttons.contains(WindowButtons::MINIMIZE) {
            mask |= NSWindowStyleMask::Miniaturizable;
        } else {
            mask &= !NSWindowStyleMask::Miniaturizable;
        }

        // This must happen before the button's "enabled" status has been set,
        // hence we do it synchronously.
        self.set_style_mask(mask);

        // We edit the button directly instead of using `NSResizableWindowMask`,
        // since that mask also affect the resizability of the window (which is
        // controllable by other means in `winit`).
        if let Some(button) = self.window().standardWindowButton(NSWindowButton::ZoomButton) {
            button.setEnabled(buttons.contains(WindowButtons::MAXIMIZE));
        }
    }

    #[inline]
    pub fn enabled_buttons(&self) -> WindowButtons {
        let mut buttons = WindowButtons::empty();
        if self.window().isMiniaturizable() {
            buttons |= WindowButtons::MINIMIZE;
        }
        if self
            .window()
            .standardWindowButton(NSWindowButton::ZoomButton)
            .map(|b| b.isEnabled())
            .unwrap_or(true)
        {
            buttons |= WindowButtons::MAXIMIZE;
        }
        if self.window().hasCloseBox() {
            buttons |= WindowButtons::CLOSE;
        }
        buttons
    }

    pub fn set_cursor(&self, cursor: Cursor) {
        let view = self.view();

        let cursor = match cursor {
            Cursor::Icon(icon) => cursor_from_icon(icon),
            Cursor::Custom(cursor) => match cursor.cast_ref::<CustomCursor>() {
                Some(cursor) => cursor.0.clone(),
                None => {
                    tracing::error!("unrecognized cursor passed to macOS backend");
                    return;
                },
            },
        };

        if view.cursor_icon() == cursor {
            return;
        }

        view.set_cursor_icon(cursor);
        self.window().invalidateCursorRectsForView(&view);
    }

    #[inline]
    pub fn set_cursor_grab(&self, mode: CursorGrabMode) -> Result<(), RequestError> {
        let associate_mouse_cursor = match mode {
            CursorGrabMode::Locked => false,
            CursorGrabMode::None => true,
            CursorGrabMode::Confined => {
                return Err(NotSupportedError::new("confined cursor is not supported").into());
            },
        };

        // TODO: Do this for real https://stackoverflow.com/a/40922095/5435443
        cgerr(CGAssociateMouseAndMouseCursorPosition(associate_mouse_cursor))?;

        Ok(())
    }

    #[inline]
    pub fn set_cursor_visible(&self, visible: bool) {
        let view = self.view();
        let state_changed = view.set_cursor_visible(visible);
        if state_changed {
            self.window().invalidateCursorRectsForView(&view);
        }
    }

    #[inline]
    pub fn scale_factor(&self) -> f64 {
        self.window().backingScaleFactor() as _
    }

    #[inline]
    pub fn set_cursor_position(&self, cursor_position: Position) -> Result<(), RequestError> {
        let content_rect = self.window().contentRectForFrameRect(self.window().frame());
        let window_position = flip_window_screen_coordinates(content_rect);
        let cursor_position = cursor_position.to_logical::<CGFloat>(self.scale_factor());
        let point = CGPoint {
            x: window_position.x + cursor_position.x,
            y: window_position.y + cursor_position.y,
        };
        cgerr(CGWarpMouseCursorPosition(point))?;
        cgerr(CGAssociateMouseAndMouseCursorPosition(true))?;

        Ok(())
    }

    #[inline]
    pub fn drag_window(&self) -> Result<(), RequestError> {
        let mtm = MainThreadMarker::from(self);
        let event =
            NSApplication::sharedApplication(mtm).currentEvent().ok_or(RequestError::Ignored)?;
        self.window().performWindowDragWithEvent(&event);
        Ok(())
    }

    #[inline]
    pub fn drag_resize_window(&self, _direction: ResizeDirection) -> Result<(), NotSupportedError> {
        Err(NotSupportedError::new("drag_resize_window is not supported"))
    }

    #[inline]
    pub fn show_window_menu(&self, _position: Position) {}

    #[inline]
    pub fn set_cursor_hittest(&self, hittest: bool) {
        self.window().setIgnoresMouseEvents(!hittest);
    }

    pub(crate) fn is_zoomed(&self) -> bool {
        // because `isZoomed` doesn't work if the window's borderless,
        // we make it resizable temporarily.
        let curr_mask = self.window().styleMask();

        let required = NSWindowStyleMask::Titled | NSWindowStyleMask::Resizable;
        let needs_temp_mask = !curr_mask.contains(required);
        if needs_temp_mask {
            self.set_style_mask(required);
        }

        let is_zoomed = self.window().isZoomed();

        // Roll back temp styles
        if needs_temp_mask {
            self.set_style_mask(curr_mask);
        }

        is_zoomed
    }

    fn saved_style(&self) -> NSWindowStyleMask {
        let base_mask =
            self.ivars().saved_style.take().unwrap_or_else(|| self.window().styleMask());
        if self.ivars().resizable.get() {
            base_mask | NSWindowStyleMask::Resizable
        } else {
            base_mask & !NSWindowStyleMask::Resizable
        }
    }

    /// This is called when the window is exiting fullscreen, whether by the
    /// user clicking on the green fullscreen button or programmatically by
    /// `toggleFullScreen:`
    pub(crate) fn restore_state_from_fullscreen(&self) {
        self.ivars().fullscreen.replace(None);

        let maximized = self.ivars().maximized.get();
        let mask = self.saved_style();

        self.set_style_mask(mask);
        self.set_maximized(maximized);
    }

    #[inline]
    pub fn set_minimized(&self, minimized: bool) {
        let is_minimized = self.window().isMiniaturized();
        if is_minimized == minimized {
            return;
        }

        if minimized {
            self.window().miniaturize(Some(self));
        } else {
            self.window().deminiaturize(Some(self));
        }
    }

    #[inline]
    pub fn is_minimized(&self) -> Option<bool> {
        Some(self.window().isMiniaturized())
    }

    #[inline]
    pub fn set_maximized(&self, maximized: bool) {
        if self.defer_if_handling_event(move |this| this.set_maximized(maximized)) {
            return;
        }

        let mtm = MainThreadMarker::from(self);
        let is_zoomed = self.is_zoomed();
        if is_zoomed == maximized {
            return;
        };

        // Save the standard frame sized if it is not zoomed
        if !is_zoomed {
            self.ivars().standard_frame.set(Some(self.window().frame()));
        }

        self.ivars().maximized.set(maximized);

        if self.ivars().fullscreen.borrow().is_some() {
            // Handle it in window_did_exit_fullscreen
            return;
        }

        if self.window().styleMask().contains(NSWindowStyleMask::Resizable) {
            // Just use the native zoom if resizable
            self.window().zoom(None);
        } else {
            // if it's not resizable, we set the frame directly
            let new_rect = if maximized {
                let screen = NSScreen::mainScreen(mtm).expect("no screen found");
                screen.visibleFrame()
            } else {
                self.ivars().standard_frame.get().unwrap_or(DEFAULT_STANDARD_FRAME)
            };
            self.window().setFrame_display(new_rect, false);
        }
    }

    #[inline]
    pub(crate) fn fullscreen(&self) -> Option<Fullscreen> {
        self.ivars().fullscreen.borrow().clone()
    }

    #[inline]
    pub fn is_maximized(&self) -> bool {
        self.is_zoomed()
    }

    #[inline]
    pub(crate) fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
        if self.ivars().is_simple_fullscreen.get() {
            return;
        }
        if fullscreen.is_some()
            && self
                .window()
                .collectionBehavior()
                .contains(NSWindowCollectionBehavior::FullScreenAuxiliary)
        {
            // `toggleFullScreen:` is silently ignored on such windows, which would leave our
            // internal fullscreen state out of sync, so bail out early instead.
            warn!(
                "cannot fullscreen a window marked as fullscreen auxiliary; call \
                 `set_fullscreen_auxiliary(false)` first"
            );
            return;
        }
        if self.ivars().in_fullscreen_transition.get() {
            // We can't set fullscreen here.
            // Set fullscreen after transition.
            self.ivars().target_fullscreen.replace(Some(fullscreen));
            return;
        }
        let old_fullscreen = self.ivars().fullscreen.borrow().clone();
        if fullscreen == old_fullscreen {
            return;
        }

        if !self.ivars().initial_fullscreen.get()
            && self.defer_if_handling_event({
                let fullscreen = fullscreen.clone();
                move |this| this.set_fullscreen(fullscreen)
            })
        {
            return;
        }

        let mtm = MainThreadMarker::from(self);
        let app = NSApplication::sharedApplication(mtm);

        // If the fullscreen is on a different monitor, we must move the window
        // to that monitor before we toggle fullscreen (as `toggleFullScreen`
        // does not take a screen parameter, but uses the current screen)
        if let Some(ref fullscreen) = fullscreen {
            let new_screen = match fullscreen {
                Fullscreen::Borderless(Some(monitor)) | Fullscreen::Exclusive(monitor, _) => {
                    let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
                    monitor.ns_screen(mtm)
                },
                _ => {
                    if let Some(monitor) = self.current_monitor_inner() {
                        monitor.ns_screen(mtm)
                    } else {
                        return;
                    }
                },
            }
            .unwrap();

            let old_screen = self.window().screen().unwrap();
            if old_screen != new_screen {
                self.window().setFrameOrigin(new_screen.frame().origin);
            }
        }

        if let Some(Fullscreen::Exclusive(ref monitor, ref video_mode)) = fullscreen {
            // Note: `enterFullScreenMode:withOptions:` seems to do the exact
            // same thing as we're doing here (captures the display, sets the
            // video mode, and hides the menu bar and dock), with the exception
            // of that I couldn't figure out how to set the display mode with
            // it. I think `enterFullScreenMode:withOptions:` is still using the
            // older display mode API where display modes were of the type
            // `CFDictionary`, but this has changed, so we can't obtain the
            // correct parameter for this any longer. Apple's code samples for
            // this function seem to just pass in "YES" for the display mode
            // parameter, which is not consistent with the docs saying that it
            // takes a `NSDictionary`..

            let display_id = monitor.native_id() as _;

            let mut fade_token = kCGDisplayFadeReservationInvalidToken;

            if matches!(old_fullscreen, Some(Fullscreen::Borderless(_))) {
                self.ivars().save_presentation_opts.replace(Some(app.presentationOptions()));
            }

            // Fade to black (and wait for the fade to complete) to hide the
            // flicker from capturing the display and switching display mode
            if cgerr(unsafe { CGAcquireDisplayFadeReservation(5.0, &mut fade_token) }).is_ok() {
                CGDisplayFade(
                    fade_token,
                    0.3,
                    kCGDisplayBlendNormal,
                    kCGDisplayBlendSolidColor,
                    0.0,
                    0.0,
                    0.0,
                    true,
                );
            }

            cgerr(CGDisplayCapture(display_id)).unwrap();

            let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
            let video_mode =
                match monitor.video_mode_handles().find(|mode| &mode.mode == video_mode) {
                    Some(video_mode) => video_mode,
                    None => return,
                };

            cgerr(unsafe {
                CGDisplaySetDisplayMode(display_id, Some(&video_mode.native_mode.0), None)
            })
            .expect("failed to set video mode");

            // After the display has been configured, fade back in
            // asynchronously
            if fade_token != kCGDisplayFadeReservationInvalidToken {
                CGDisplayFade(
                    fade_token,
                    0.6,
                    kCGDisplayBlendSolidColor,
                    kCGDisplayBlendNormal,
                    0.0,
                    0.0,
                    0.0,
                    false,
                );
                CGReleaseDisplayFadeReservation(fade_token);
            }
        }

        self.ivars().fullscreen.replace(fullscreen.clone());

        fn toggle_fullscreen(window: &NSWindow) {
            // Window level must be restored from `CGShieldingWindowLevel()
            // + 1` back to normal in order for `toggleFullScreen` to do
            // anything
            window.setLevel(kCGNormalWindowLevel as NSWindowLevel);
            window.toggleFullScreen(None);
        }

        match (old_fullscreen, fullscreen) {
            (None, Some(_)) => {
                // `toggleFullScreen` doesn't work if the `StyleMask` is none, so we
                // set a normal style temporarily. The previous state will be
                // restored in `WindowDelegate::window_did_exit_fullscreen`.
                let curr_mask = self.window().styleMask();
                let required = NSWindowStyleMask::Titled | NSWindowStyleMask::Resizable;
                if !curr_mask.contains(required) {
                    self.set_style_mask(required);
                    self.ivars().saved_style.set(Some(curr_mask));
                }

                toggle_fullscreen(self.window());
            },
            (Some(Fullscreen::Borderless(_)), None) => {
                // State is restored by `window_did_exit_fullscreen`
                toggle_fullscreen(self.window());
            },
            (Some(Fullscreen::Exclusive(monitor, _)), None) => {
                let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
                restore_and_release_display(monitor);
                toggle_fullscreen(self.window());
            },
            (Some(Fullscreen::Borderless(_)), Some(Fullscreen::Exclusive(..))) => {
                // If we're already in fullscreen mode, calling
                // `CGDisplayCapture` will place the shielding window on top of
                // our window, which results in a black display and is not what
                // we want. So, we must place our window on top of the shielding
                // window. Unfortunately, this also makes our window be on top
                // of the menu bar, and this looks broken, so we must make sure
                // that the menu bar is disabled. This is done in the window
                // delegate in `window:willUseFullScreenPresentationOptions:`.
                self.ivars().save_presentation_opts.set(Some(app.presentationOptions()));

                let presentation_options = NSApplicationPresentationOptions::FullScreen
                    | NSApplicationPresentationOptions::HideDock
                    | NSApplicationPresentationOptions::HideMenuBar;
                app.setPresentationOptions(presentation_options);

                let window_level = CGShieldingWindowLevel() as NSWindowLevel + 1;
                self.window().setLevel(window_level);
            },
            (Some(Fullscreen::Exclusive(monitor, _)), Some(Fullscreen::Borderless(_))) => {
                let presentation_options = self.ivars().save_presentation_opts.get().unwrap_or(
                    NSApplicationPresentationOptions::FullScreen
                        | NSApplicationPresentationOptions::AutoHideDock
                        | NSApplicationPresentationOptions::AutoHideMenuBar,
                );
                app.setPresentationOptions(presentation_options);

                let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
                restore_and_release_display(monitor);

                // Restore the normal window level following the Borderless fullscreen
                // `CGShieldingWindowLevel() + 1` hack.
                self.window().setLevel(kCGNormalWindowLevel as NSWindowLevel);
            },
            _ => {},
        };
    }

    #[inline]
    pub fn set_decorations(&self, decorations: bool) {
        if decorations == self.ivars().decorations.get() {
            return;
        }

        self.ivars().decorations.set(decorations);

        let fullscreen = self.ivars().fullscreen.borrow().is_some();
        let resizable = self.ivars().resizable.get();

        // If we're in fullscreen mode, we wait to apply decoration changes
        // until we're in `window_did_exit_fullscreen`.
        if fullscreen {
            return;
        }

        let new_mask = {
            let mut new_mask = if decorations {
                NSWindowStyleMask::Closable
                    | NSWindowStyleMask::Miniaturizable
                    | NSWindowStyleMask::Resizable
                    | NSWindowStyleMask::Titled
            } else {
                NSWindowStyleMask::Borderless | NSWindowStyleMask::Resizable
            };
            if !resizable {
                new_mask &= !NSWindowStyleMask::Resizable;
            }
            new_mask
        };
        self.set_style_mask(new_mask);
    }

    #[inline]
    pub fn is_decorated(&self) -> bool {
        self.ivars().decorations.get()
    }

    #[inline]
    pub fn set_window_level(&self, level: WindowLevel) {
        // Note: There are two different things at play here:
        // `CGWindowLevel` and `CGWindowLevelKey`.
        //
        // It seems like there was a push towards using "key" values instead of the
        // raw window level values, and then you were supposed to use
        // `CGWindowLevelForKey` to get the actual level.
        //
        // But the values that `NSWindowLevel` has are compiled in, and as such has
        // to remain ABI compatible, so they're safe for us to hardcode as well.
        let level = match level {
            WindowLevel::AlwaysOnTop => kCGFloatingWindowLevel as NSWindowLevel,
            WindowLevel::AlwaysOnBottom => (kCGNormalWindowLevel - 1) as NSWindowLevel,
            WindowLevel::Normal => kCGNormalWindowLevel as NSWindowLevel,
        };
        self.window().setLevel(level);
    }

    #[inline]
    pub fn set_window_icon(&self, _icon: Option<Icon>) {
        // macOS doesn't have window icons. Though, there is
        // `setRepresentedFilename`, but that's semantically distinct and should
        // only be used when the window is in some way representing a specific
        // file/directory. For instance, Terminal.app uses this for the CWD.
        // Anyway, that should eventually be implemented as
        // `WindowAttributesExt::with_represented_file` or something, and doesn't
        // have anything to do with `set_window_icon`.
        // https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/WinPanel/Tasks/SettingWindowTitle.html
    }

    pub fn request_ime_update(&self, request: ImeRequest) -> Result<(), ImeRequestError> {
        let current_caps = self.view().ime_capabilities();
        let request_data = match request {
            ImeRequest::Enable(enable) => {
                let (capabilities, request_data) = enable.into_raw();
                if current_caps.is_some() {
                    return Err(ImeRequestError::AlreadyEnabled);
                }
                self.view().enable_ime(capabilities);
                request_data
            },
            ImeRequest::Update(request_data) => {
                if current_caps.is_none() {
                    return Err(ImeRequestError::NotEnabled);
                }
                request_data
            },
            ImeRequest::Disable => {
                self.view().disable_ime();
                return Ok(());
            },
            _ => return Err(ImeRequestError::NotSupported),
        };

        if let Some((spot, size)) = request_data.cursor_area {
            if self.view().ime_capabilities().unwrap().cursor_area() {
                let scale_factor = self.scale_factor();
                let logical_spot = spot.to_logical(scale_factor);
                let logical_spot = NSPoint::new(logical_spot.x, logical_spot.y);

                let size = size.to_logical(scale_factor);
                let size = NSSize::new(size.width, size.height);
                self.view().set_ime_cursor_area(logical_spot, size);
            } else {
                warn!("discarding IME cursor area update without capability enabled.");
            }
        }

        Ok(())
    }

    pub fn ime_capabilities(&self) -> Option<ImeCapabilities> {
        self.view().ime_capabilities()
    }

    #[inline]
    pub fn focus_window(&self) {
        let mtm = MainThreadMarker::from(self);
        let is_minimized = self.window().isMiniaturized();
        let is_visible = self.window().isVisible();

        if !is_minimized && is_visible {
            #[allow(deprecated)]
            NSApplication::sharedApplication(mtm).activateIgnoringOtherApps(true);
            self.window().makeKeyAndOrderFront(None);
        }
    }

    #[inline]
    pub fn request_user_attention(&self, request_type: Option<UserAttentionType>) {
        let mtm = MainThreadMarker::from(self);
        let ns_request_type = request_type.map(|ty| match ty {
            UserAttentionType::Critical => NSRequestUserAttentionType::CriticalRequest,
            UserAttentionType::Informational => NSRequestUserAttentionType::InformationalRequest,
        });
        if let Some(ty) = ns_request_type {
            NSApplication::sharedApplication(mtm).requestUserAttention(ty);
        }
    }

    #[inline]
    // Allow directly accessing the current monitor internally without unwrapping.
    pub(crate) fn current_monitor_inner(&self) -> Option<MonitorHandle> {
        let display_id = get_display_id(&*self.window().screen()?);
        if let Some(monitor) = MonitorHandle::new(display_id) {
            Some(monitor)
        } else {
            // NOTE: Display ID was just fetched from live NSScreen, but can still result in `None`
            // with certain Thunderbolt docked monitors.
            warn!(display_id, "got screen with invalid display ID");
            None
        }
    }

    #[inline]
    pub fn current_monitor(&self) -> Option<MonitorHandle> {
        self.current_monitor_inner()
    }

    #[inline]
    pub fn available_monitors(&self) -> VecDeque<MonitorHandle> {
        monitor::available_monitors()
    }

    #[inline]
    pub fn primary_monitor(&self) -> Option<MonitorHandle> {
        let monitor = monitor::primary_monitor();
        Some(monitor)
    }

    #[inline]
    pub fn raw_window_handle_rwh_06(&self) -> rwh_06::RawWindowHandle {
        let window_handle = rwh_06::AppKitWindowHandle::new({
            let ptr = Retained::as_ptr(&self.view()) as *mut _;
            std::ptr::NonNull::new(ptr).expect("Retained<T> should never be null")
        });
        rwh_06::RawWindowHandle::AppKit(window_handle)
    }

    fn toggle_style_mask(&self, mask: NSWindowStyleMask, on: bool) {
        let current_style_mask = self.window().styleMask();
        if on {
            self.set_style_mask(current_style_mask | mask);
        } else {
            self.set_style_mask(current_style_mask & !mask);
        }
    }

    #[inline]
    pub fn has_focus(&self) -> bool {
        self.window().isKeyWindow()
    }

    pub fn theme(&self) -> Option<Theme> {
        self.window().appearance().map(|appearance| appearance_to_theme(&appearance)).or_else(
            || {
                let mtm = MainThreadMarker::from(self);
                let app = NSApplication::sharedApplication(mtm);

                if available!(macos = 10.14) {
                    Some(super::window_delegate::appearance_to_theme(&app.effectiveAppearance()))
                } else {
                    Some(Theme::Light)
                }
            },
        )
    }

    pub fn set_theme(&self, theme: Option<Theme>) {
        self.window().setAppearance(theme_to_appearance(theme).as_deref());
    }

    #[inline]
    pub fn set_content_protected(&self, protected: bool) {
        self.window().setSharingType(if protected {
            NSWindowSharingType::None
        } else {
            NSWindowSharingType::ReadOnly
        })
    }

    pub fn title(&self) -> String {
        self.window().title().to_string()
    }

    pub fn reset_dead_keys(&self) {
        // (Artur) I couldn't find a way to implement this.
    }
}

fn restore_and_release_display(monitor: &MonitorHandle) {
    let available_monitors = monitor::available_monitors();
    if available_monitors.contains(monitor) {
        CGRestorePermanentDisplayConfiguration();
        cgerr(CGDisplayRelease(monitor.native_id() as _)).unwrap();
    } else {
        warn!(
            monitor = monitor.name().map(|name| name.to_string()),
            "Tried to restore exclusive fullscreen on a monitor that is no longer available"
        );
    }
}

#[cfg(not(feature = "private-apple-apis"))]
fn ns_visual_effect_material(material: BlurMaterial) -> Option<NSVisualEffectMaterial> {
    match material {
        BlurMaterial::Titlebar => Some(NSVisualEffectMaterial::Titlebar),
        BlurMaterial::Selection => Some(NSVisualEffectMaterial::Selection),
        BlurMaterial::Menu => available!(macos = 10.11).then_some(NSVisualEffectMaterial::Menu),
        BlurMaterial::Popover => {
            available!(macos = 10.11).then_some(NSVisualEffectMaterial::Popover)
        },
        BlurMaterial::Sidebar => {
            available!(macos = 10.11).then_some(NSVisualEffectMaterial::Sidebar)
        },
        BlurMaterial::HeaderView => {
            available!(macos = 10.14).then_some(NSVisualEffectMaterial::HeaderView)
        },
        BlurMaterial::FullScreenUI => {
            available!(macos = 10.14).then_some(NSVisualEffectMaterial::FullScreenUI)
        },
        BlurMaterial::HudWindow => {
            available!(macos = 10.14).then_some(NSVisualEffectMaterial::HUDWindow)
        },
        BlurMaterial::ToolTip => {
            available!(macos = 10.14).then_some(NSVisualEffectMaterial::ToolTip)
        },
        BlurMaterial::UnderWindowBackground => {
            available!(macos = 10.14).then_some(NSVisualEffectMaterial::UnderWindowBackground)
        },
    }
}

impl WindowExtMacOS for WindowDelegate {
    #[inline]
    fn simple_fullscreen(&self) -> bool {
        self.ivars().is_simple_fullscreen.get()
    }

    #[inline]
    fn set_simple_fullscreen(&self, fullscreen: bool) -> bool {
        let mtm = MainThreadMarker::from(self);

        let app = NSApplication::sharedApplication(mtm);
        let is_native_fullscreen = self.ivars().fullscreen.borrow().is_some();
        let is_simple_fullscreen = self.ivars().is_simple_fullscreen.get();

        // Do nothing if native fullscreen is active.
        if is_native_fullscreen
            || (fullscreen && is_simple_fullscreen)
            || (!fullscreen && !is_simple_fullscreen)
        {
            return false;
        }

        if fullscreen {
            // Remember the original window's settings
            // Exclude title bar
            self.ivars()
                .standard_frame
                .set(Some(self.window().contentRectForFrameRect(self.window().frame())));
            self.ivars().saved_style.set(Some(self.window().styleMask()));
            self.ivars().save_presentation_opts.set(Some(app.presentationOptions()));

            // Tell our window's state that we're in fullscreen
            self.ivars().is_simple_fullscreen.set(true);

            // Simulate pre-Lion fullscreen by hiding the dock and menu bar
            let presentation_options = if self.is_borderless_game() {
                NSApplicationPresentationOptions::HideDock
                    | NSApplicationPresentationOptions::HideMenuBar
            } else {
                NSApplicationPresentationOptions::AutoHideDock
                    | NSApplicationPresentationOptions::AutoHideMenuBar
            };
            app.setPresentationOptions(presentation_options);

            // Hide the titlebar
            self.toggle_style_mask(NSWindowStyleMask::Titled, false);

            // Set the window frame to the screen frame size
            let screen = self.window().screen().expect("expected screen to be available");
            self.window().setFrame_display(screen.frame(), true);

            // Configure the safe area rectangle, to ensure that we don't obscure the notch.
            if NSScreen::class().responds_to(sel!(safeAreaInsets)) {
                self.view().setAdditionalSafeAreaInsets(screen.safeAreaInsets());
            }

            // Fullscreen windows can't be resized, minimized, or moved
            self.toggle_style_mask(NSWindowStyleMask::Miniaturizable, false);
            self.toggle_style_mask(NSWindowStyleMask::Resizable, false);
            self.window().setMovable(false);
        } else {
            let new_mask = self.saved_style();
            self.ivars().is_simple_fullscreen.set(false);

            let save_presentation_opts = self.ivars().save_presentation_opts.get();
            let frame = self.ivars().standard_frame.get().unwrap_or(DEFAULT_STANDARD_FRAME);

            if let Some(presentation_opts) = save_presentation_opts {
                app.setPresentationOptions(presentation_opts);
            }

            if NSScreen::class().responds_to(sel!(safeAreaInsets)) {
                self.view().setAdditionalSafeAreaInsets(NSEdgeInsets {
                    top: 0.0,
                    left: 0.0,
                    bottom: 0.0,
                    right: 0.0,
                });
            }

            self.window().setFrame_display(frame, true);
            self.window().setMovable(true);
            self.set_style_mask(new_mask);
        }

        true
    }

    #[inline]
    fn has_shadow(&self) -> bool {
        self.window().hasShadow()
    }

    #[inline]
    fn set_has_shadow(&self, has_shadow: bool) {
        self.window().setHasShadow(has_shadow)
    }

    #[inline]
    fn set_tabbing_identifier(&self, identifier: &str) {
        self.window().setTabbingIdentifier(&NSString::from_str(identifier))
    }

    #[inline]
    fn tabbing_identifier(&self) -> String {
        self.window().tabbingIdentifier().to_string()
    }

    #[inline]
    fn select_next_tab(&self) {
        self.window().selectNextTab(None)
    }

    #[inline]
    fn select_previous_tab(&self) {
        self.window().selectPreviousTab(None)
    }

    #[inline]
    fn select_tab_at_index(&self, index: usize) {
        if !available!(macos = 10.13) {
            tracing::warn!("window tab groups are only available on macOS 10.13+");
            return;
        }
        if let Some(group) = self.window().tabGroup() {
            if let Some(windows) = self.window().tabbedWindows() {
                if index < windows.len() {
                    group.setSelectedWindow(Some(&windows.objectAtIndex(index)));
                }
            }
        }
    }

    #[inline]
    fn num_tabs(&self) -> usize {
        self.window().tabbedWindows().map(|windows| windows.len()).unwrap_or(1)
    }

    fn is_document_edited(&self) -> bool {
        self.window().isDocumentEdited()
    }

    fn set_document_edited(&self, edited: bool) {
        self.window().setDocumentEdited(edited)
    }

    fn set_option_as_alt(&self, option_as_alt: OptionAsAlt) {
        self.view().set_option_as_alt(option_as_alt);
    }

    fn set_blur_material(&self, blur_material: BlurMaterial) {
        self.ivars().blur_material.set(blur_material);

        #[cfg(not(feature = "private-apple-apis"))]
        if let Some(blur_view) = self.ivars().blur_view.borrow().as_ref() {
            if let Some(material) = ns_visual_effect_material(blur_material) {
                blur_view.setMaterial(material);
            }
        }
    }

    fn blur_material(&self) -> BlurMaterial {
        self.ivars().blur_material.get()
    }

    fn option_as_alt(&self) -> OptionAsAlt {
        self.view().option_as_alt()
    }

    fn set_borderless_game(&self, borderless_game: bool) {
        self.ivars().is_borderless_game.set(borderless_game);
    }

    fn is_borderless_game(&self) -> bool {
        self.ivars().is_borderless_game.get()
    }

    fn set_unified_titlebar(&self, unified_titlebar: bool) {
        let window = self.window();

        if unified_titlebar {
            let mtm = MainThreadMarker::from(self);

            // The toolbar style is ignored if there is no toolbar, so it is
            // necessary to add one.
            window.setToolbar(Some(&NSToolbar::new(mtm)));
            window.setToolbarStyle(NSWindowToolbarStyle::Unified);
        } else {
            window.setToolbar(None);
            window.setToolbarStyle(NSWindowToolbarStyle::Automatic);
        }
    }

    fn unified_titlebar(&self) -> bool {
        let window = self.window();

        window.toolbar().is_some() && window.toolbarStyle() == NSWindowToolbarStyle::Unified
    }

    #[inline]
    fn set_fullscreen_auxiliary(&self, fullscreen_auxiliary: bool) {
        let window = self.window();
        let behavior = window.collectionBehavior();
        if fullscreen_auxiliary {
            window
                .setCollectionBehavior(behavior | NSWindowCollectionBehavior::FullScreenAuxiliary);
        } else {
            window
                .setCollectionBehavior(behavior - NSWindowCollectionBehavior::FullScreenAuxiliary);
        }
    }

    #[inline]
    fn fullscreen_auxiliary(&self) -> bool {
        self.window().collectionBehavior().contains(NSWindowCollectionBehavior::FullScreenAuxiliary)
    }
}

const DEFAULT_STANDARD_FRAME: NSRect =
    NSRect::new(NSPoint::new(50.0, 50.0), NSSize::new(800.0, 600.0));

fn dark_appearance_name() -> &'static NSString {
    // Don't use the static `NSAppearanceNameDarkAqua` to allow linking on macOS < 10.14
    ns_string!("NSAppearanceNameDarkAqua")
}

pub fn appearance_to_theme(appearance: &NSAppearance) -> Theme {
    let best_match = appearance.bestMatchFromAppearancesWithNames(&NSArray::from_slice(&[
        unsafe { NSAppearanceNameAqua },
        dark_appearance_name(),
    ]));
    if let Some(best_match) = best_match {
        if *best_match == *dark_appearance_name() { Theme::Dark } else { Theme::Light }
    } else {
        warn!(?appearance, "failed to determine the theme of the appearance");
        // Default to light in this case
        Theme::Light
    }
}

fn theme_to_appearance(theme: Option<Theme>) -> Option<Retained<NSAppearance>> {
    let appearance = match theme? {
        Theme::Light => unsafe { NSAppearance::appearanceNamed(NSAppearanceNameAqua) },
        Theme::Dark => NSAppearance::appearanceNamed(dark_appearance_name()),
    };
    if let Some(appearance) = appearance {
        Some(appearance)
    } else {
        warn!(?theme, "could not find appearance for theme");
        // Assume system appearance in this case
        None
    }
}