Desktop: Fix resize helper window Z-order and attach to parent console on Windows (#3572)

* Desktop: Fix helper window zorder on Windows

* Attach to parent console if launched from a terminal

* Workaround for a Windows-specific exception that occurs when `app` is dropped

Author: timon-schelling

desktop/Cargo.toml

@@ -55,6 +55,7 @@ windows = { version = "0.58.0", features = [
 	"Win32_Graphics_Gdi",
 	"Win32_System_LibraryLoader",
 	"Win32_System_Com",
+	"Win32_System_Console",
 	"Win32_UI_Controls",
 	"Win32_UI_WindowsAndMessaging",
 	"Win32_UI_HiDpi",

desktop/src/lib.rs

@@ -93,6 +93,14 @@ pub fn start() {
 	let mut app = App::new(Box::new(cef_context), cef_view_info_sender, wgpu_context, app_event_receiver, app_event_scheduler, cli.files);
 
 	event_loop.run_app(&mut app).unwrap();
+
+	// Workaround for a Windows-specific exception that occurs when `app` is dropped.
+	// The issue causes the window to hang for a few seconds before closing.
+	// Appears to be related to CEF object destruction order.
+	// Calling `exit` bypasses rust teardown and lets Windows perform process cleanup.
+	// TODO: Identify and fix the underlying CEF shutdown issue so this workaround can be removed.
+	#[cfg(target_os = "windows")]
+	exit(0);
 }
 
 pub fn start_helper() {

desktop/src/window/win.rs

@@ -1,4 +1,5 @@
 use windows::Win32::System::Com::{COINIT_APARTMENTTHREADED, CoInitializeEx};
+use windows::Win32::System::Console::{ATTACH_PARENT_PROCESS, AttachConsole};
 use windows::Win32::UI::Shell::SetCurrentProcessExplicitAppUserModelID;
 use windows::core::HSTRING;
 use winit::event_loop::ActiveEventLoop;
@@ -13,6 +14,12 @@ pub(super) struct NativeWindowImpl {
 
 impl super::NativeWindow for NativeWindowImpl {
 	fn init() {
+		// Attach to parent console if launched from a terminal (no-op otherwise)
+		unsafe {
+			let _ = AttachConsole(ATTACH_PARENT_PROCESS);
+		}
+
+		// Set stable app ID
 		let app_id = HSTRING::from(APP_ID);
 		unsafe {
 			let _ = CoInitializeEx(None, COINIT_APARTMENTTHREADED).ok();

desktop/src/window/win/native_handle.rs

@@ -61,7 +61,7 @@ impl NativeWindowHandle {
 				0,
 				0,
 				0,
-				None,
+				main,
 				None,
 				HINSTANCE(std::ptr::null_mut()),
 				// Pass the main window's HWND to WM_NCCREATE so the helper can store it.
@@ -118,7 +118,7 @@ impl NativeWindowHandle {
 		}
 
 		// Force window update
-		let _ = unsafe { SetWindowPos(main, None, 0, 0, 0, 0, SWP_FRAMECHANGED | SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER) };
+		let _ = unsafe { SetWindowPos(main, None, 0, 0, 0, 0, SWP_FRAMECHANGED | SWP_NOMOVE | SWP_NOSIZE) };
 
 		native_handle
 	}
@@ -325,20 +325,20 @@ unsafe fn position_helper(main: HWND, helper: HWND) {
 	let w = (r.right - r.left) + RESIZE_BAND_THICKNESS * 2;
 	let h = (r.bottom - r.top) + RESIZE_BAND_THICKNESS * 2;
 
-	let _ = unsafe { SetWindowPos(helper, main, x, y, w, h, SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOOWNERZORDER | SWP_NOSENDCHANGING) };
+	let _ = unsafe { SetWindowPos(helper, main, x, y, w, h, SWP_NOACTIVATE | SWP_NOSENDCHANGING) };
 }
 
 unsafe fn calculate_hit(helper: HWND, lparam: LPARAM) -> u32 {
-	let x = (lparam.0 & 0xFFFF) as i16 as u32;
-	let y = ((lparam.0 >> 16) & 0xFFFF) as i16 as u32;
+	let x = (lparam.0 & 0xFFFF) as i16 as i32;
+	let y = ((lparam.0 >> 16) & 0xFFFF) as i16 as i32;
 
 	let mut r = RECT::default();
 	let _ = unsafe { GetWindowRect(helper, &mut r) };
 
-	let on_top = y < (r.top + RESIZE_BAND_THICKNESS) as u32;
-	let on_right = x >= (r.right - RESIZE_BAND_THICKNESS) as u32;
-	let on_bottom = y >= (r.bottom - RESIZE_BAND_THICKNESS) as u32;
-	let on_left = x < (r.left + RESIZE_BAND_THICKNESS) as u32;
+	let on_top = y < (r.top + RESIZE_BAND_THICKNESS) as i32;
+	let on_right = x >= (r.right - RESIZE_BAND_THICKNESS) as i32;
+	let on_bottom = y >= (r.bottom - RESIZE_BAND_THICKNESS) as i32;
+	let on_left = x < (r.left + RESIZE_BAND_THICKNESS) as i32;
 
 	match (on_top, on_right, on_bottom, on_left) {
 		(true, _, _, true) => HTTOPLEFT,