winit/src/platform_impl/ios/view.rs

#![allow(clippy::unnecessary_cast)]

use objc2::foundation::{CGFloat, CGRect, MainThreadMarker, NSObject, NSSet};
use objc2::rc::{Id, Shared};
use objc2::runtime::Class;
use objc2::{declare_class, extern_methods, msg_send, msg_send_id, ClassType};

use super::uikit::{
    UIApplication, UIDevice, UIEvent, UIForceTouchCapability, UIInterfaceOrientationMask,
    UIResponder, UITouch, UITouchPhase, UITouchType, UITraitCollection, UIView, UIViewController,
    UIWindow,
};
use super::window::WindowId;
use crate::{
    dpi::PhysicalPosition,
    event::{DeviceId as RootDeviceId, Event, Force, Touch, TouchPhase, WindowEvent},
    platform::ios::ValidOrientations,
    platform_impl::platform::{
        app_state,
        event_loop::{EventProxy, EventWrapper},
        ffi::{UIRectEdge, UIUserInterfaceIdiom},
        window::PlatformSpecificWindowBuilderAttributes,
        DeviceId, Fullscreen,
    },
    window::{WindowAttributes, WindowId as RootWindowId},
};

declare_class!(
    pub(crate) struct WinitView {}

    unsafe impl ClassType for WinitView {
        #[inherits(UIResponder, NSObject)]
        type Super = UIView;
        const NAME: &'static str = "WinitUIView";
    }

    unsafe impl WinitView {
        #[sel(drawRect:)]
        fn draw_rect(&self, rect: CGRect) {
            let window = self.window().unwrap();
            unsafe {
                app_state::handle_nonuser_events(
                    std::iter::once(EventWrapper::StaticEvent(Event::RedrawRequested(
                        RootWindowId(window.id()),
                    )))
                    .chain(std::iter::once(EventWrapper::StaticEvent(
                        Event::RedrawEventsCleared,
                    ))),
                );
            }
            let _: () = unsafe { msg_send![super(self), drawRect: rect] };
        }

        #[sel(layoutSubviews)]
        fn layout_subviews(&self) {
            let _: () = unsafe { msg_send![super(self), layoutSubviews] };

            let window = self.window().unwrap();
            let window_bounds = window.bounds();
            let screen = window.screen();
            let screen_space = screen.coordinateSpace();
            let screen_frame = self.convertRect_toCoordinateSpace(window_bounds, &screen_space);
            let scale_factor = screen.scale();
            let size = crate::dpi::LogicalSize {
                width: screen_frame.size.width as f64,
                height: screen_frame.size.height as f64,
            }
            .to_physical(scale_factor as f64);

            // If the app is started in landscape, the view frame and window bounds can be mismatched.
            // The view frame will be in portrait and the window bounds in landscape. So apply the
            // window bounds to the view frame to make it consistent.
            let view_frame = self.frame();
            if view_frame != window_bounds {
                self.setFrame(window_bounds);
            }

            unsafe {
                app_state::handle_nonuser_event(EventWrapper::StaticEvent(Event::WindowEvent {
                    window_id: RootWindowId(window.id()),
                    event: WindowEvent::Resized(size),
                }));
            }
        }

        #[sel(setContentScaleFactor:)]
        fn set_content_scale_factor(&self, untrusted_scale_factor: CGFloat) {
            let _: () =
                unsafe { msg_send![super(self), setContentScaleFactor: untrusted_scale_factor] };

            // `window` is null when `setContentScaleFactor` is invoked prior to `[UIWindow
            // makeKeyAndVisible]` at window creation time (either manually or internally by
            // UIKit when the `UIView` is first created), in which case we send no events here
            let window = match self.window() {
                Some(window) => window,
                None => return,
            };
            // `setContentScaleFactor` may be called with a value of 0, which means "reset the
            // content scale factor to a device-specific default value", so we can't use the
            // parameter here. We can query the actual factor using the getter
            let scale_factor = self.contentScaleFactor();
            assert!(
                !scale_factor.is_nan()
                    && scale_factor.is_finite()
                    && scale_factor.is_sign_positive()
                    && scale_factor > 0.0,
                "invalid scale_factor set on UIView",
            );
            let scale_factor = scale_factor as f64;
            let bounds = self.bounds();
            let screen = window.screen();
            let screen_space = screen.coordinateSpace();
            let screen_frame = self.convertRect_toCoordinateSpace(bounds, &screen_space);
            let size = crate::dpi::LogicalSize {
                width: screen_frame.size.width as _,
                height: screen_frame.size.height as _,
            };
            let window_id = RootWindowId(window.id());
            unsafe {
                app_state::handle_nonuser_events(
                    std::iter::once(EventWrapper::EventProxy(EventProxy::DpiChangedProxy {
                        window,
                        scale_factor,
                        suggested_size: size,
                    }))
                    .chain(std::iter::once(EventWrapper::StaticEvent(
                        Event::WindowEvent {
                            window_id,
                            event: WindowEvent::Resized(size.to_physical(scale_factor)),
                        },
                    ))),
                );
            }
        }

        #[sel(touchesBegan:withEvent:)]
        fn touches_began(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
            self.handle_touches(touches)
        }

        #[sel(touchesMoved:withEvent:)]
        fn touches_moved(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
            self.handle_touches(touches)
        }

        #[sel(touchesEnded:withEvent:)]
        fn touches_ended(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
            self.handle_touches(touches)
        }

        #[sel(touchesCancelled:withEvent:)]
        fn touches_cancelled(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
            self.handle_touches(touches)
        }
    }
);

extern_methods!(
    #[allow(non_snake_case)]
    unsafe impl WinitView {
        fn window(&self) -> Option<Id<WinitUIWindow, Shared>> {
            unsafe { msg_send_id![self, window] }
        }

        unsafe fn traitCollection(&self) -> Id<UITraitCollection, Shared> {
            msg_send_id![self, traitCollection]
        }

        // TODO: Allow the user to customize this
        #[sel(layerClass)]
        pub(crate) fn layerClass() -> &'static Class;
    }
);

impl WinitView {
    pub(crate) fn new(
        _mtm: MainThreadMarker,
        _window_attributes: &WindowAttributes,
        platform_attributes: &PlatformSpecificWindowBuilderAttributes,
        frame: CGRect,
    ) -> Id<Self, Shared> {
        let this: Id<Self, Shared> =
            unsafe { msg_send_id![msg_send_id![Self::class(), alloc], initWithFrame: frame] };

        this.setMultipleTouchEnabled(true);

        if let Some(scale_factor) = platform_attributes.scale_factor {
            this.setContentScaleFactor(scale_factor as _);
        }

        this
    }

    fn handle_touches(&self, touches: &NSSet<UITouch>) {
        let window = self.window().unwrap();
        let uiscreen = window.screen();
        let mut touch_events = Vec::new();
        let os_supports_force = app_state::os_capabilities().force_touch;
        for touch in touches {
            let logical_location = touch.locationInView(None);
            let touch_type = touch.type_();
            let force = if os_supports_force {
                let trait_collection = unsafe { self.traitCollection() };
                let touch_capability = trait_collection.forceTouchCapability();
                // Both the OS _and_ the device need to be checked for force touch support.
                if touch_capability == UIForceTouchCapability::Available {
                    let force = touch.force();
                    let max_possible_force = touch.maximumPossibleForce();
                    let altitude_angle: Option<f64> = if touch_type == UITouchType::Pencil {
                        let angle = touch.altitudeAngle();
                        Some(angle as _)
                    } else {
                        None
                    };
                    Some(Force::Calibrated {
                        force: force as _,
                        max_possible_force: max_possible_force as _,
                        altitude_angle,
                    })
                } else {
                    None
                }
            } else {
                None
            };
            let touch_id = touch as *const UITouch as u64;
            let phase = touch.phase();
            let phase = match phase {
                UITouchPhase::Began => TouchPhase::Started,
                UITouchPhase::Moved => TouchPhase::Moved,
                // 2 is UITouchPhase::Stationary and is not expected here
                UITouchPhase::Ended => TouchPhase::Ended,
                UITouchPhase::Cancelled => TouchPhase::Cancelled,
                _ => panic!("unexpected touch phase: {:?}", phase as i32),
            };

            let physical_location = {
                let scale_factor = self.contentScaleFactor();
                PhysicalPosition::from_logical::<(f64, f64), f64>(
                    (logical_location.x as _, logical_location.y as _),
                    scale_factor as f64,
                )
            };
            touch_events.push(EventWrapper::StaticEvent(Event::WindowEvent {
                window_id: RootWindowId(window.id()),
                event: WindowEvent::Touch(Touch {
                    device_id: RootDeviceId(DeviceId {
                        uiscreen: Id::as_ptr(&uiscreen),
                    }),
                    id: touch_id,
                    location: physical_location,
                    force,
                    phase,
                }),
            }));
        }
        unsafe {
            app_state::handle_nonuser_events(touch_events);
        }
    }
}

declare_class!(
    pub(crate) struct WinitViewController {
        _prefers_status_bar_hidden: bool,
        _prefers_home_indicator_auto_hidden: bool,
        _supported_orientations: UIInterfaceOrientationMask,
        _preferred_screen_edges_deferring_system_gestures: UIRectEdge,
    }

    unsafe impl ClassType for WinitViewController {
        #[inherits(UIResponder, NSObject)]
        type Super = UIViewController;
        const NAME: &'static str = "WinitUIViewController";
    }

    unsafe impl WinitViewController {
        #[sel(shouldAutorotate)]
        fn should_autorotate(&self) -> bool {
            true
        }
    }

    unsafe impl WinitViewController {
        #[sel(prefersStatusBarHidden)]
        fn prefers_status_bar_hidden(&self) -> bool {
            *self._prefers_status_bar_hidden
        }

        #[sel(setPrefersStatusBarHidden:)]
        fn set_prefers_status_bar_hidden(&mut self, val: bool) {
            *self._prefers_status_bar_hidden = val;
            self.setNeedsStatusBarAppearanceUpdate();
        }

        #[sel(prefersHomeIndicatorAutoHidden)]
        fn prefers_home_indicator_auto_hidden(&self) -> bool {
            *self._prefers_home_indicator_auto_hidden
        }

        #[sel(setPrefersHomeIndicatorAutoHidden:)]
        fn set_prefers_home_indicator_auto_hidden(&mut self, val: bool) {
            *self._prefers_home_indicator_auto_hidden = val;
            let os_capabilities = app_state::os_capabilities();
            if os_capabilities.home_indicator_hidden {
                self.setNeedsUpdateOfHomeIndicatorAutoHidden();
            } else {
                os_capabilities.home_indicator_hidden_err_msg("ignoring")
            }
        }

        #[sel(supportedInterfaceOrientations)]
        fn supported_orientations(&self) -> UIInterfaceOrientationMask {
            *self._supported_orientations
        }

        #[sel(setSupportedInterfaceOrientations:)]
        fn set_supported_orientations(&mut self, val: UIInterfaceOrientationMask) {
            *self._supported_orientations = val;
            UIViewController::attemptRotationToDeviceOrientation();
        }

        #[sel(preferredScreenEdgesDeferringSystemGestures)]
        fn preferred_screen_edges_deferring_system_gestures(&self) -> UIRectEdge {
            *self._preferred_screen_edges_deferring_system_gestures
        }

        #[sel(setPreferredScreenEdgesDeferringSystemGestures:)]
        fn set_preferred_screen_edges_deferring_system_gestures(&mut self, val: UIRectEdge) {
            *self._preferred_screen_edges_deferring_system_gestures = val;
            let os_capabilities = app_state::os_capabilities();
            if os_capabilities.defer_system_gestures {
                self.setNeedsUpdateOfScreenEdgesDeferringSystemGestures();
            } else {
                os_capabilities.defer_system_gestures_err_msg("ignoring")
            }
        }
    }
);

extern_methods!(
    #[allow(non_snake_case)]
    unsafe impl WinitViewController {
        #[sel(setPrefersStatusBarHidden:)]
        pub(crate) fn setPrefersStatusBarHidden(&self, flag: bool);

        #[sel(setSupportedInterfaceOrientations:)]
        pub(crate) fn setSupportedInterfaceOrientations(&self, val: UIInterfaceOrientationMask);

        #[sel(setPrefersHomeIndicatorAutoHidden:)]
        pub(crate) fn setPrefersHomeIndicatorAutoHidden(&self, val: bool);

        #[sel(setPreferredScreenEdgesDeferringSystemGestures:)]
        pub(crate) fn setPreferredScreenEdgesDeferringSystemGestures(&self, val: UIRectEdge);
    }
);

impl WinitViewController {
    pub(crate) fn set_supported_interface_orientations(
        &self,
        mtm: MainThreadMarker,
        valid_orientations: ValidOrientations,
    ) {
        let mask = match (
            valid_orientations,
            UIDevice::current(mtm).userInterfaceIdiom(),
        ) {
            (ValidOrientations::LandscapeAndPortrait, UIUserInterfaceIdiom::Phone) => {
                UIInterfaceOrientationMask::AllButUpsideDown
            }
            (ValidOrientations::LandscapeAndPortrait, _) => UIInterfaceOrientationMask::All,
            (ValidOrientations::Landscape, _) => UIInterfaceOrientationMask::Landscape,
            (ValidOrientations::Portrait, UIUserInterfaceIdiom::Phone) => {
                UIInterfaceOrientationMask::Portrait
            }
            (ValidOrientations::Portrait, _) => {
                UIInterfaceOrientationMask::Portrait
                    | UIInterfaceOrientationMask::PortraitUpsideDown
            }
        };
        self.setSupportedInterfaceOrientations(mask);
    }

    pub(crate) fn new(
        mtm: MainThreadMarker,
        _window_attributes: &WindowAttributes,
        platform_attributes: &PlatformSpecificWindowBuilderAttributes,
        view: &UIView,
    ) -> Id<Self, Shared> {
        let this: Id<Self, Shared> =
            unsafe { msg_send_id![msg_send_id![Self::class(), alloc], init] };

        this.setPrefersStatusBarHidden(platform_attributes.prefers_status_bar_hidden);

        this.set_supported_interface_orientations(mtm, platform_attributes.valid_orientations);

        this.setPrefersHomeIndicatorAutoHidden(platform_attributes.prefers_home_indicator_hidden);

        this.setPreferredScreenEdgesDeferringSystemGestures(
            platform_attributes
                .preferred_screen_edges_deferring_system_gestures
                .into(),
        );

        this.setView(Some(view));

        this
    }
}

declare_class!(
    #[derive(Debug, PartialEq, Eq, Hash)]
    pub(crate) struct WinitUIWindow {}

    unsafe impl ClassType for WinitUIWindow {
        #[inherits(UIResponder, NSObject)]
        type Super = UIWindow;
    }

    unsafe impl WinitUIWindow {
        #[sel(becomeKeyWindow)]
        fn become_key_window(&self) {
            unsafe {
                app_state::handle_nonuser_event(EventWrapper::StaticEvent(Event::WindowEvent {
                    window_id: RootWindowId(self.id()),
                    event: WindowEvent::Focused(true),
                }));
            }
            let _: () = unsafe { msg_send![super(self), becomeKeyWindow] };
        }

        #[sel(resignKeyWindow)]
        fn resign_key_window(&self) {
            unsafe {
                app_state::handle_nonuser_event(EventWrapper::StaticEvent(Event::WindowEvent {
                    window_id: RootWindowId(self.id()),
                    event: WindowEvent::Focused(false),
                }));
            }
            let _: () = unsafe { msg_send![super(self), resignKeyWindow] };
        }
    }
);

impl WinitUIWindow {
    pub(crate) fn new(
        _mtm: MainThreadMarker,
        window_attributes: &WindowAttributes,
        _platform_attributes: &PlatformSpecificWindowBuilderAttributes,
        frame: CGRect,
        view_controller: &UIViewController,
    ) -> Id<Self, Shared> {
        let this: Id<Self, Shared> =
            unsafe { msg_send_id![msg_send_id![Self::class(), alloc], initWithFrame: frame] };

        this.setRootViewController(Some(view_controller));

        match window_attributes.fullscreen {
            Some(Fullscreen::Exclusive(ref video_mode)) => {
                let monitor = video_mode.monitor();
                let screen = monitor.ui_screen();
                screen.setCurrentMode(Some(&video_mode.screen_mode.0));
                this.setScreen(screen);
            }
            Some(Fullscreen::Borderless(Some(ref monitor))) => {
                let screen = monitor.ui_screen();
                this.setScreen(screen);
            }
            _ => (),
        }

        this
    }

    pub(crate) fn id(&self) -> WindowId {
        (self as *const Self as usize as u64).into()
    }
}

declare_class!(
    pub struct WinitApplicationDelegate {}

    unsafe impl ClassType for WinitApplicationDelegate {
        type Super = NSObject;
    }

    // UIApplicationDelegate protocol
    unsafe impl WinitApplicationDelegate {
        #[sel(application:didFinishLaunchingWithOptions:)]
        fn did_finish_launching(&self, _application: &UIApplication, _: *mut NSObject) -> bool {
            unsafe {
                app_state::did_finish_launching();
            }
            true
        }

        #[sel(applicationDidBecomeActive:)]
        fn did_become_active(&self, _application: &UIApplication) {
            unsafe { app_state::handle_nonuser_event(EventWrapper::StaticEvent(Event::Resumed)) }
        }

        #[sel(applicationWillResignActive:)]
        fn will_resign_active(&self, _application: &UIApplication) {
            unsafe { app_state::handle_nonuser_event(EventWrapper::StaticEvent(Event::Suspended)) }
        }

        #[sel(applicationWillEnterForeground:)]
        fn will_enter_foreground(&self, _application: &UIApplication) {}
        #[sel(applicationDidEnterBackground:)]
        fn did_enter_background(&self, _application: &UIApplication) {}

        #[sel(applicationWillTerminate:)]
        fn will_terminate(&self, application: &UIApplication) {
            let mut events = Vec::new();
            for window in application.windows().iter() {
                if window.is_kind_of::<WinitUIWindow>() {
                    // SAFETY: We just checked that the window is a `winit` window
                    let window = unsafe {
                        let ptr: *const UIWindow = window;
                        let ptr: *const WinitUIWindow = ptr.cast();
                        &*ptr
                    };
                    events.push(EventWrapper::StaticEvent(Event::WindowEvent {
                        window_id: RootWindowId(window.id()),
                        event: WindowEvent::Destroyed,
                    }));
                }
            }
            unsafe {
                app_state::handle_nonuser_events(events);
                app_state::terminated();
            }
        }
    }
);