Move UIKit backend to winit-uikit

.github/CODEOWNERS

@@ -2,7 +2,7 @@
 /winit-android                      @MarijnS95
 
 # Apple (AppKit + UIKit)
-/src/platform/ios.rs                @madsmtm
+/winit-uikit                        @madsmtm
 /src/platform/macos.rs              @madsmtm
 /src/platform_impl/apple            @madsmtm
 /winit-common/src/core_foundation   @madsmtm

.github/workflows/ci.yml

@@ -201,6 +201,11 @@ jobs:
       if: contains(matrix.platform.target, 'redox')
       run: cargo test -p winit-orbital
 
+    - name: Test winit UIKit
+      if: contains(matrix.platform.target, 'ios')
+      # TODO: Run on Simulator
+      run: cargo $CMD test -p winit-uikit --target=${{ matrix.platform.target }} --no-run
+
     - name: Test winit Win32
       if: contains(matrix.platform.target, 'windows')
       run: cargo $CMD test -p winit-win32 --target=${{ matrix.platform.target }}

Cargo.toml

@@ -16,6 +16,7 @@ winit-android = { version = "0.0.0", path = "winit-android" }
 winit-common = { version = "0.0.0", path = "winit-common" }
 winit-core = { version = "0.0.0", path = "winit-core" }
 winit-orbital = { version = "0.0.0", path = "winit-orbital" }
+winit-uikit = { version = "0.0.0", path = "winit-uikit" }
 winit-win32 = { version = "0.0.0", path = "winit-win32" }
 
 # Core dependencies.
@@ -164,6 +165,7 @@ serde = [
     "dpi/serde",
     "bitflags/serde",
     "winit-core/serde",
+    "winit-uikit/serde",
 ]
 wayland = [
     "wayland-client",
@@ -296,52 +298,8 @@ objc2-foundation = { workspace = true, features = [
     "NSValue",
 ] }
 
-# UIKit
 [target.'cfg(all(target_vendor = "apple", not(target_os = "macos")))'.dependencies]
-objc2-core-foundation = { workspace = true, features = [
-    "std",
-    "CFCGTypes",
-    "CFBase",
-    "CFRunLoop",
-    "CFString",
-] }
-objc2-foundation = { workspace = true, features = [
-    "std",
-    "block2",
-    "objc2-core-foundation",
-    "NSArray",
-    "NSEnumerator",
-    "NSGeometry",
-    "NSObjCRuntime",
-    "NSOperation",
-    "NSString",
-    "NSThread",
-    "NSSet",
-] }
-objc2-ui-kit = { workspace = true, features = [
-    "std",
-    "objc2-core-foundation",
-    "UIApplication",
-    "UIDevice",
-    "UIEvent",
-    "UIGeometry",
-    "UIGestureRecognizer",
-    "UITextInput",
-    "UITextInputTraits",
-    "UIOrientation",
-    "UIPanGestureRecognizer",
-    "UIPinchGestureRecognizer",
-    "UIResponder",
-    "UIRotationGestureRecognizer",
-    "UIScreen",
-    "UIScreenMode",
-    "UITapGestureRecognizer",
-    "UITouch",
-    "UITraitCollection",
-    "UIView",
-    "UIViewController",
-    "UIWindow",
-] }
+winit-uikit.workspace = true
 
 [target.'cfg(target_os = "windows")'.dependencies]
 winit-win32.workspace = true

src/platform/mod.rs

@@ -5,7 +5,7 @@
 #[cfg(android_platform)]
 pub use winit_android as android;
 #[cfg(ios_platform)]
-pub mod ios;
+pub use winit_uikit as ios;
 #[cfg(macos_platform)]
 pub mod macos;
 #[cfg(orbital_platform)]

src/platform_impl/apple/mod.rs

@@ -1,11 +1,6 @@
 #[cfg(target_os = "macos")]
 mod appkit;
-#[cfg(not(target_os = "macos"))]
-mod uikit;
 
 #[allow(unused_imports)]
 #[cfg(target_os = "macos")]
 pub use self::appkit::*;
-#[allow(unused_imports)]
-#[cfg(not(target_os = "macos"))]
-pub use self::uikit::*;

src/platform_impl/apple/uikit/mod.rs

@@ -1,26 +0,0 @@
-#![allow(clippy::let_unit_value)]
-
-mod app_state;
-mod event_loop;
-mod monitor;
-mod notification_center;
-mod view;
-mod view_controller;
-mod window;
-
-use std::fmt;
-
-pub(crate) use self::event_loop::{
-    ActiveEventLoop, EventLoop, PlatformSpecificEventLoopAttributes,
-};
-pub(crate) use self::monitor::MonitorHandle;
-pub(crate) use self::window::Window;
-
-#[derive(Debug)]
-pub enum OsError {}
-
-impl fmt::Display for OsError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "os error")
-    }
-}

src/platform_impl/apple/uikit/notification_center.rs

@@ -1 +0,0 @@
-../appkit/notification_center.rs

src/platform_impl/mod.rs

@@ -1,17 +1,19 @@
 #[cfg(android_platform)]
 pub(crate) use winit_android as platform;
-#[cfg(target_vendor = "apple")]
+#[cfg(macos_platform)]
 mod apple;
 #[cfg(any(x11_platform, wayland_platform))]
 mod linux;
 #[cfg(orbital_platform)]
 pub(crate) use winit_orbital as platform;
+#[cfg(ios_platform)]
+pub(crate) use winit_uikit as platform;
 #[cfg(web_platform)]
 mod web;
 #[cfg(windows_platform)]
 pub(crate) use winit_win32 as platform;
 
-#[cfg(target_vendor = "apple")]
+#[cfg(macos_platform)]
 use self::apple as platform;
 #[cfg(any(x11_platform, wayland_platform))]
 use self::linux as platform;

winit-uikit/Cargo.toml

@@ -0,0 +1,72 @@
+[package]
+description = "Winit's UIKit (iOS/tvOS/visionOS) backend"
+documentation = "https://docs.rs/winit-uikit"
+edition.workspace = true
+license.workspace = true
+name = "winit-uikit"
+repository.workspace = true
+rust-version.workspace = true
+version = "0.0.0"
+
+[features]
+serde = ["dep:serde", "bitflags/serde", "smol_str/serde", "dpi/serde"]
+
+[dependencies]
+bitflags.workspace = true
+dpi.workspace = true
+rwh_06.workspace = true
+serde = { workspace = true, optional = true }
+smol_str.workspace = true
+tracing.workspace = true
+winit-common = { workspace = true, features = ["core-foundation", "event-handler"] }
+winit-core.workspace = true
+
+# Platform-specific
+[target.'cfg(target_vendor = "apple")'.dependencies]
+block2.workspace = true
+dispatch2.workspace = true
+objc2.workspace = true
+objc2-core-foundation = { workspace = true, features = [
+    "std",
+    "CFCGTypes",
+    "CFBase",
+    "CFRunLoop",
+    "CFString",
+] }
+objc2-foundation = { workspace = true, features = [
+    "std",
+    "block2",
+    "objc2-core-foundation",
+    "NSArray",
+    "NSEnumerator",
+    "NSGeometry",
+    "NSObjCRuntime",
+    "NSOperation",
+    "NSString",
+    "NSThread",
+    "NSSet",
+] }
+objc2-ui-kit = { workspace = true, features = [
+    "std",
+    "objc2-core-foundation",
+    "UIApplication",
+    "UIDevice",
+    "UIEvent",
+    "UIGeometry",
+    "UIGestureRecognizer",
+    "UITextInput",
+    "UITextInputTraits",
+    "UIOrientation",
+    "UIPanGestureRecognizer",
+    "UIPinchGestureRecognizer",
+    "UIResponder",
+    "UIRotationGestureRecognizer",
+    "UIScreen",
+    "UIScreenMode",
+    "UITapGestureRecognizer",
+    "UITouch",
+    "UITraitCollection",
+    "UIView",
+    "UIViewController",
+    "UIWindow",
+] }

winit-uikit/README.md

@@ -0,0 +1 @@
+../README.md

winit-uikit/src/app_state.rs

@@ -23,8 +23,8 @@ use winit_core::event::{StartCause, SurfaceSizeWriter, WindowEvent};
 use winit_core::event_loop::ControlFlow;
 use winit_core::window::WindowId;
 
-use super::window::WinitUIWindow;
-use super::ActiveEventLoop;
+use crate::event_loop::ActiveEventLoop;
+use crate::window::WinitUIWindow;
 
 macro_rules! bug {
     ($($msg:tt)*) => {

winit-uikit/src/event_loop.rs

@@ -28,11 +28,12 @@ use winit_core::window::{Theme, Window as CoreWindow};
 
 use super::app_state::{send_occluded_event_for_all_windows, AppState};
 use super::notification_center::create_observer;
-use super::{app_state, monitor, MonitorHandle};
-use crate::platform_impl::Window;
+use crate::monitor::MonitorHandle;
+use crate::window::Window;
+use crate::{app_state, monitor};
 
 #[derive(Debug)]
-pub(crate) struct ActiveEventLoop {
+pub struct ActiveEventLoop {
     pub(super) mtm: MainThreadMarker,
 }
 
@@ -138,12 +139,10 @@ pub struct EventLoop {
 }
 
 #[derive(Default, Debug, Copy, Clone, PartialEq, Eq, Hash)]
-pub(crate) struct PlatformSpecificEventLoopAttributes {}
+pub struct PlatformSpecificEventLoopAttributes {}
 
 impl EventLoop {
-    pub(crate) fn new(
-        _: &PlatformSpecificEventLoopAttributes,
-    ) -> Result<EventLoop, EventLoopError> {
+    pub fn new(_: &PlatformSpecificEventLoopAttributes) -> Result<EventLoop, EventLoopError> {
         let mtm = MainThreadMarker::new()
             .expect("On iOS, `EventLoop` must be created on the main thread");
 

winit-uikit/src/lib.rs

@@ -1,4 +1,4 @@
-//! # iOS / UIKit
+//! # Winit's UIKit (iOS/tvOS/visionOS) backend
 //!
 //! Winit has [the same iOS version requirements as `rustc`][rustc-ios-version], although it's
 //! frequently only tested on newer iOS versions.
@@ -98,16 +98,26 @@
 //! register an application delegate, so you can set up a custom one in a nib file instead.
 //!
 //! [app-delegate]: https://developer.apple.com/documentation/uikit/uiapplicationdelegate?language=objc
+#![cfg(target_vendor = "apple")] // TODO: Remove once `objc2` allows compiling on all platforms
+
+mod app_state;
+mod event_loop;
+mod monitor;
+mod notification_center;
+mod view;
+mod view_controller;
+mod window;
 
 use std::os::raw::c_void;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-use winit_core::window::PlatformWindowAttributes;
+use winit_core::monitor::{MonitorHandle, VideoMode};
+use winit_core::window::{PlatformWindowAttributes, Window};
 
-use crate::monitor::{MonitorHandle, VideoMode};
-use crate::platform_impl::MonitorHandle as IosMonitorHandle;
-use crate::window::Window;
+pub use self::event_loop::{EventLoop, PlatformSpecificEventLoopAttributes};
+use self::monitor::MonitorHandle as UIKitMonitorHandle;
+use self::window::Window as UIKitWindow;
 
 /// Additional methods on [`Window`] that are specific to iOS.
 pub trait WindowExtIOS {
@@ -212,25 +222,25 @@ pub trait WindowExtIOS {
 impl WindowExtIOS for dyn Window + '_ {
     #[inline]
     fn set_scale_factor(&self, scale_factor: f64) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_scale_factor(scale_factor));
     }
 
     #[inline]
     fn set_valid_orientations(&self, valid_orientations: ValidOrientations) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_valid_orientations(valid_orientations));
     }
 
     #[inline]
     fn set_prefers_home_indicator_hidden(&self, hidden: bool) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_prefers_home_indicator_hidden(hidden));
     }
 
     #[inline]
     fn set_preferred_screen_edges_deferring_system_gestures(&self, edges: ScreenEdge) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| {
             w.set_preferred_screen_edges_deferring_system_gestures(edges)
         });
@@ -238,19 +248,19 @@ impl WindowExtIOS for dyn Window + '_ {
 
     #[inline]
     fn set_prefers_status_bar_hidden(&self, hidden: bool) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_prefers_status_bar_hidden(hidden));
     }
 
     #[inline]
     fn set_preferred_status_bar_style(&self, status_bar_style: StatusBarStyle) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_preferred_status_bar_style(status_bar_style))
     }
 
     #[inline]
     fn recognize_pinch_gesture(&self, should_recognize: bool) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| w.recognize_pinch_gesture(should_recognize));
     }
 
@@ -261,7 +271,7 @@ impl WindowExtIOS for dyn Window + '_ {
         minimum_number_of_touches: u8,
         maximum_number_of_touches: u8,
     ) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| {
             w.recognize_pan_gesture(
                 should_recognize,
@@ -273,13 +283,13 @@ impl WindowExtIOS for dyn Window + '_ {
 
     #[inline]
     fn recognize_doubletap_gesture(&self, should_recognize: bool) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| w.recognize_doubletap_gesture(should_recognize));
     }
 
     #[inline]
     fn recognize_rotation_gesture(&self, should_recognize: bool) {
-        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<UIKitWindow>().unwrap();
         window.maybe_wait_on_main(move |w| w.recognize_rotation_gesture(should_recognize));
     }
 }
@@ -395,13 +405,13 @@ impl MonitorHandleExtIOS for MonitorHandle {
     fn ui_screen(&self) -> *mut c_void {
         // SAFETY: The marker is only used to get the pointer of the screen
         let mtm = unsafe { objc2::MainThreadMarker::new_unchecked() };
-        let monitor = self.cast_ref::<IosMonitorHandle>().unwrap();
+        let monitor = self.cast_ref::<UIKitMonitorHandle>().unwrap();
         objc2::rc::Retained::as_ptr(monitor.ui_screen(mtm)) as *mut c_void
     }
 
     #[inline]
     fn preferred_video_mode(&self) -> VideoMode {
-        let monitor = self.cast_ref::<IosMonitorHandle>().unwrap();
+        let monitor = self.cast_ref::<UIKitMonitorHandle>().unwrap();
         monitor.preferred_video_mode()
     }
 }

winit-uikit/src/notification_center.rs

@@ -0,0 +1 @@
+../../src/platform_impl/apple/appkit/notification_center.rs

winit-uikit/src/view_controller.rs

@@ -8,7 +8,7 @@ use objc2_ui_kit::{
     UIUserInterfaceIdiom, UIView, UIViewController,
 };
 
-use crate::platform::ios::{ScreenEdge, StatusBarStyle, ValidOrientations, WindowAttributesIos};
+use crate::{ScreenEdge, StatusBarStyle, ValidOrientations, WindowAttributesIos};
 
 pub struct ViewControllerState {
     prefers_status_bar_hidden: Cell<bool>,

winit-uikit/src/window.rs

@@ -30,8 +30,10 @@ use winit_core::window::{
 use super::app_state::EventWrapper;
 use super::view::WinitView;
 use super::view_controller::WinitViewController;
-use super::{app_state, monitor, ActiveEventLoop, MonitorHandle};
-use crate::platform::ios::{ScreenEdge, StatusBarStyle, ValidOrientations, WindowAttributesIos};
+use super::{app_state, monitor};
+use crate::event_loop::ActiveEventLoop;
+use crate::monitor::MonitorHandle;
+use crate::{ScreenEdge, StatusBarStyle, ValidOrientations, WindowAttributesIos};
 
 define_class!(
     #[unsafe(super(UIWindow, UIResponder, NSObject))]