From 485ae90aaea5cd1d316168bea714bee05bd3e140 Mon Sep 17 00:00:00 2001
From: Shane Celis <shane.celis@gmail.com>
Date: Tue, 22 Oct 2024 07:00:53 -0400
Subject: [PATCH] macOS: fix panic during drag_window

Return error from it instead of unwrapping.
---
 src/changelog/unreleased.md                |   3 +-
 src/platform_impl/apple/appkit/window.rs   | 369 +++++++++++++++++++++
 src/platform_impl/macos/window_delegate.rs |   3 +-
 3 files changed, 373 insertions(+), 2 deletions(-)
 create mode 100644 src/platform_impl/apple/appkit/window.rs

diff --git a/src/changelog/unreleased.md b/src/changelog/unreleased.md
index 2c2a254be..086df8be0 100644
--- a/src/changelog/unreleased.md
+++ b/src/changelog/unreleased.md
@@ -48,6 +48,7 @@ changelog entry.
 ### Fixed
 
 - On macOS, fix `WindowEvent::Moved` sometimes being triggered unnecessarily on resize.
-- On MacOS, package manifest definitions of `LSUIElement` will no longer be overridden with the
+- On macOS, package manifest definitions of `LSUIElement` will no longer be overridden with the
   default activation policy, unless explicitly provided during initialization.
+- On macOS, fix crash when calling `drag_window()` without a left click present.
 - On X11, key events forward to IME anyway, even when it's disabled.
diff --git a/src/platform_impl/apple/appkit/window.rs b/src/platform_impl/apple/appkit/window.rs
new file mode 100644
index 000000000..be59dbed9
--- /dev/null
+++ b/src/platform_impl/apple/appkit/window.rs
@@ -0,0 +1,369 @@
+#![allow(clippy::unnecessary_cast)]
+
+use dpi::{Position, Size};
+use objc2::rc::{autoreleasepool, Retained};
+use objc2::{declare_class, mutability, ClassType, DeclaredClass};
+use objc2_app_kit::{NSResponder, NSWindow};
+use objc2_foundation::{MainThreadBound, MainThreadMarker, NSObject};
+
+use super::event_loop::ActiveEventLoop;
+use super::window_delegate::WindowDelegate;
+use crate::error::RequestError;
+use crate::monitor::MonitorHandle as CoreMonitorHandle;
+use crate::window::{
+    Cursor, Fullscreen, Icon, ImePurpose, Theme, UserAttentionType, Window as CoreWindow,
+    WindowAttributes, WindowButtons, WindowId, WindowLevel,
+};
+
+pub(crate) struct Window {
+    window: MainThreadBound<Retained<WinitWindow>>,
+    /// The window only keeps a weak reference to this, so we must keep it around here.
+    delegate: MainThreadBound<Retained<WindowDelegate>>,
+}
+
+impl Window {
+    pub(crate) fn new(
+        window_target: &ActiveEventLoop,
+        attributes: WindowAttributes,
+    ) -> Result<Self, RequestError> {
+        let mtm = window_target.mtm;
+        let delegate =
+            autoreleasepool(|_| WindowDelegate::new(&window_target.app_state, attributes, mtm))?;
+        Ok(Window {
+            window: MainThreadBound::new(delegate.window().retain(), mtm),
+            delegate: MainThreadBound::new(delegate, mtm),
+        })
+    }
+
+    pub(crate) fn maybe_wait_on_main<R: Send>(
+        &self,
+        f: impl FnOnce(&WindowDelegate) -> R + Send,
+    ) -> R {
+        self.delegate.get_on_main(|delegate| f(delegate))
+    }
+
+    #[cfg(feature = "rwh_06")]
+    #[inline]
+    pub(crate) fn raw_window_handle_rwh_06(
+        &self,
+    ) -> Result<rwh_06::RawWindowHandle, rwh_06::HandleError> {
+        if let Some(mtm) = MainThreadMarker::new() {
+            Ok(self.delegate.get(mtm).raw_window_handle_rwh_06())
+        } else {
+            Err(rwh_06::HandleError::Unavailable)
+        }
+    }
+
+    #[cfg(feature = "rwh_06")]
+    #[inline]
+    pub(crate) fn raw_display_handle_rwh_06(
+        &self,
+    ) -> Result<rwh_06::RawDisplayHandle, rwh_06::HandleError> {
+        Ok(rwh_06::RawDisplayHandle::AppKit(rwh_06::AppKitDisplayHandle::new()))
+    }
+}
+
+impl Drop for Window {
+    fn drop(&mut self) {
+        // Restore the video mode.
+        if matches!(self.fullscreen(), Some(Fullscreen::Exclusive(_))) {
+            self.set_fullscreen(None);
+        }
+
+        self.window.get_on_main(|window| autoreleasepool(|_| window.close()))
+    }
+}
+
+#[cfg(feature = "rwh_06")]
+impl rwh_06::HasDisplayHandle for Window {
+    fn display_handle(&self) -> Result<rwh_06::DisplayHandle<'_>, rwh_06::HandleError> {
+        let raw = self.raw_display_handle_rwh_06()?;
+        unsafe { Ok(rwh_06::DisplayHandle::borrow_raw(raw)) }
+    }
+}
+
+#[cfg(feature = "rwh_06")]
+impl rwh_06::HasWindowHandle for Window {
+    fn window_handle(&self) -> Result<rwh_06::WindowHandle<'_>, rwh_06::HandleError> {
+        let raw = self.raw_window_handle_rwh_06()?;
+        unsafe { Ok(rwh_06::WindowHandle::borrow_raw(raw)) }
+    }
+}
+
+impl CoreWindow for Window {
+    fn id(&self) -> crate::window::WindowId {
+        self.maybe_wait_on_main(|delegate| delegate.id())
+    }
+
+    fn scale_factor(&self) -> f64 {
+        self.maybe_wait_on_main(|delegate| delegate.scale_factor())
+    }
+
+    fn request_redraw(&self) {
+        self.maybe_wait_on_main(|delegate| delegate.request_redraw());
+    }
+
+    fn pre_present_notify(&self) {
+        self.maybe_wait_on_main(|delegate| delegate.pre_present_notify());
+    }
+
+    fn reset_dead_keys(&self) {
+        self.maybe_wait_on_main(|delegate| delegate.reset_dead_keys());
+    }
+
+    fn inner_position(&self) -> Result<dpi::PhysicalPosition<i32>, RequestError> {
+        Ok(self.maybe_wait_on_main(|delegate| delegate.inner_position()))
+    }
+
+    fn outer_position(&self) -> Result<dpi::PhysicalPosition<i32>, RequestError> {
+        Ok(self.maybe_wait_on_main(|delegate| delegate.outer_position()))
+    }
+
+    fn set_outer_position(&self, position: Position) {
+        self.maybe_wait_on_main(|delegate| delegate.set_outer_position(position));
+    }
+
+    fn surface_size(&self) -> dpi::PhysicalSize<u32> {
+        self.maybe_wait_on_main(|delegate| delegate.surface_size())
+    }
+
+    fn request_surface_size(&self, size: Size) -> Option<dpi::PhysicalSize<u32>> {
+        self.maybe_wait_on_main(|delegate| delegate.request_surface_size(size))
+    }
+
+    fn outer_size(&self) -> dpi::PhysicalSize<u32> {
+        self.maybe_wait_on_main(|delegate| delegate.outer_size())
+    }
+
+    fn set_min_surface_size(&self, min_size: Option<Size>) {
+        self.maybe_wait_on_main(|delegate| delegate.set_min_surface_size(min_size))
+    }
+
+    fn set_max_surface_size(&self, max_size: Option<Size>) {
+        self.maybe_wait_on_main(|delegate| delegate.set_max_surface_size(max_size));
+    }
+
+    fn surface_resize_increments(&self) -> Option<dpi::PhysicalSize<u32>> {
+        self.maybe_wait_on_main(|delegate| delegate.surface_resize_increments())
+    }
+
+    fn set_surface_resize_increments(&self, increments: Option<Size>) {
+        self.maybe_wait_on_main(|delegate| delegate.set_surface_resize_increments(increments));
+    }
+
+    fn set_title(&self, title: &str) {
+        self.maybe_wait_on_main(|delegate| delegate.set_title(title));
+    }
+
+    fn set_transparent(&self, transparent: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_transparent(transparent));
+    }
+
+    fn set_blur(&self, blur: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_blur(blur));
+    }
+
+    fn set_visible(&self, visible: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_visible(visible));
+    }
+
+    fn is_visible(&self) -> Option<bool> {
+        self.maybe_wait_on_main(|delegate| delegate.is_visible())
+    }
+
+    fn set_resizable(&self, resizable: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_resizable(resizable))
+    }
+
+    fn is_resizable(&self) -> bool {
+        self.maybe_wait_on_main(|delegate| delegate.is_resizable())
+    }
+
+    fn set_enabled_buttons(&self, buttons: WindowButtons) {
+        self.maybe_wait_on_main(|delegate| delegate.set_enabled_buttons(buttons))
+    }
+
+    fn enabled_buttons(&self) -> WindowButtons {
+        self.maybe_wait_on_main(|delegate| delegate.enabled_buttons())
+    }
+
+    fn set_minimized(&self, minimized: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_minimized(minimized));
+    }
+
+    fn is_minimized(&self) -> Option<bool> {
+        self.maybe_wait_on_main(|delegate| delegate.is_minimized())
+    }
+
+    fn set_maximized(&self, maximized: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_maximized(maximized));
+    }
+
+    fn is_maximized(&self) -> bool {
+        self.maybe_wait_on_main(|delegate| delegate.is_maximized())
+    }
+
+    fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
+        self.maybe_wait_on_main(|delegate| delegate.set_fullscreen(fullscreen.map(Into::into)))
+    }
+
+    fn fullscreen(&self) -> Option<Fullscreen> {
+        self.maybe_wait_on_main(|delegate| delegate.fullscreen().map(Into::into))
+    }
+
+    fn set_decorations(&self, decorations: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_decorations(decorations));
+    }
+
+    fn is_decorated(&self) -> bool {
+        self.maybe_wait_on_main(|delegate| delegate.is_decorated())
+    }
+
+    fn set_window_level(&self, level: WindowLevel) {
+        self.maybe_wait_on_main(|delegate| delegate.set_window_level(level));
+    }
+
+    fn set_window_icon(&self, window_icon: Option<Icon>) {
+        self.maybe_wait_on_main(|delegate| delegate.set_window_icon(window_icon));
+    }
+
+    fn set_ime_cursor_area(&self, position: Position, size: Size) {
+        self.maybe_wait_on_main(|delegate| delegate.set_ime_cursor_area(position, size));
+    }
+
+    fn set_ime_allowed(&self, allowed: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_ime_allowed(allowed));
+    }
+
+    fn set_ime_purpose(&self, purpose: ImePurpose) {
+        self.maybe_wait_on_main(|delegate| delegate.set_ime_purpose(purpose));
+    }
+
+    fn focus_window(&self) {
+        self.maybe_wait_on_main(|delegate| delegate.focus_window());
+    }
+
+    fn has_focus(&self) -> bool {
+        self.maybe_wait_on_main(|delegate| delegate.has_focus())
+    }
+
+    fn request_user_attention(&self, request_type: Option<UserAttentionType>) {
+        self.maybe_wait_on_main(|delegate| delegate.request_user_attention(request_type));
+    }
+
+    fn set_theme(&self, theme: Option<Theme>) {
+        self.maybe_wait_on_main(|delegate| delegate.set_theme(theme));
+    }
+
+    fn theme(&self) -> Option<Theme> {
+        self.maybe_wait_on_main(|delegate| delegate.theme())
+    }
+
+    fn set_content_protected(&self, protected: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_content_protected(protected));
+    }
+
+    fn title(&self) -> String {
+        self.maybe_wait_on_main(|delegate| delegate.title())
+    }
+
+    fn set_cursor(&self, cursor: Cursor) {
+        self.maybe_wait_on_main(|delegate| delegate.set_cursor(cursor));
+    }
+
+    fn set_cursor_position(&self, position: Position) -> Result<(), RequestError> {
+        self.maybe_wait_on_main(|delegate| delegate.set_cursor_position(position))
+    }
+
+    fn set_cursor_grab(&self, mode: crate::window::CursorGrabMode) -> Result<(), RequestError> {
+        self.maybe_wait_on_main(|delegate| delegate.set_cursor_grab(mode))
+    }
+
+    fn set_cursor_visible(&self, visible: bool) {
+        self.maybe_wait_on_main(|delegate| delegate.set_cursor_visible(visible))
+    }
+
+    fn drag_window(&self) -> Result<(), RequestError> {
+        self.maybe_wait_on_main(|delegate| delegate.drag_window())
+    }
+
+    fn drag_resize_window(
+        &self,
+        direction: crate::window::ResizeDirection,
+    ) -> Result<(), RequestError> {
+        Ok(self.maybe_wait_on_main(|delegate| delegate.drag_resize_window(direction))?)
+    }
+
+    fn show_window_menu(&self, position: Position) {
+        self.maybe_wait_on_main(|delegate| delegate.show_window_menu(position))
+    }
+
+    fn set_cursor_hittest(&self, hittest: bool) -> Result<(), RequestError> {
+        self.maybe_wait_on_main(|delegate| delegate.set_cursor_hittest(hittest));
+        Ok(())
+    }
+
+    fn current_monitor(&self) -> Option<CoreMonitorHandle> {
+        self.maybe_wait_on_main(|delegate| {
+            delegate.current_monitor().map(|inner| CoreMonitorHandle { inner })
+        })
+    }
+
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
+        self.maybe_wait_on_main(|delegate| {
+            Box::new(
+                delegate.available_monitors().into_iter().map(|inner| CoreMonitorHandle { inner }),
+            )
+        })
+    }
+
+    fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
+        self.maybe_wait_on_main(|delegate| {
+            delegate.primary_monitor().map(|inner| CoreMonitorHandle { inner })
+        })
+    }
+
+    #[cfg(feature = "rwh_06")]
+    fn rwh_06_display_handle(&self) -> &dyn rwh_06::HasDisplayHandle {
+        self
+    }
+
+    #[cfg(feature = "rwh_06")]
+    fn rwh_06_window_handle(&self) -> &dyn rwh_06::HasWindowHandle {
+        self
+    }
+}
+
+declare_class!(
+    #[derive(Debug)]
+    pub struct WinitWindow;
+
+    unsafe impl ClassType for WinitWindow {
+        #[inherits(NSResponder, NSObject)]
+        type Super = NSWindow;
+        type Mutability = mutability::MainThreadOnly;
+        const NAME: &'static str = "WinitWindow";
+    }
+
+    impl DeclaredClass for WinitWindow {}
+
+    unsafe impl WinitWindow {
+        #[method(canBecomeMainWindow)]
+        fn can_become_main_window(&self) -> bool {
+            trace_scope!("canBecomeMainWindow");
+            true
+        }
+
+        #[method(canBecomeKeyWindow)]
+        fn can_become_key_window(&self) -> bool {
+            trace_scope!("canBecomeKeyWindow");
+            true
+        }
+    }
+);
+
+impl WinitWindow {
+    pub(super) fn id(&self) -> WindowId {
+        WindowId::from_raw(self as *const Self as usize)
+    }
+}
diff --git a/src/platform_impl/macos/window_delegate.rs b/src/platform_impl/macos/window_delegate.rs
index 8aa8a269f..19dc605e0 100644
--- a/src/platform_impl/macos/window_delegate.rs
+++ b/src/platform_impl/macos/window_delegate.rs
@@ -1163,7 +1163,8 @@ impl WindowDelegate {
     #[inline]
     pub fn drag_window(&self) -> Result<(), ExternalError> {
         let mtm = MainThreadMarker::from(self);
-        let event = NSApplication::sharedApplication(mtm).currentEvent().unwrap();
+        let event =
+            NSApplication::sharedApplication(mtm).currentEvent().ok_or(ExternalError::Ignored)?;
         self.window().performWindowDragWithEvent(&event);
         Ok(())
     }