Windows: Split window initialization across NCCREATE and CREATE (rust…

…-windowing#2062)

* Refactor window initialization by splitting NCCREATE and CREATE related tasks.

Fixes issue with invisible owner windows.

* address review comments

* Update src/platform_impl/windows/event_loop.rs

Co-authored-by: Markus Røyset <maroider@protonmail.com>

Co-authored-by: Markus Røyset <maroider@protonmail.com>

src/platform_impl/windows/event_loop.rs

@@ -38,7 +38,7 @@ use crate::{
     monitor::MonitorHandle as RootMonitorHandle,
     platform_impl::platform::{
         dark_mode::try_theme,
-        dpi::{become_dpi_aware, dpi_to_scale_factor, enable_non_client_dpi_scaling},
+        dpi::{become_dpi_aware, dpi_to_scale_factor},
         drop_handler::FileDropHandler,
         event::{self, handle_extended_keys, process_key_params, vkey_to_winit_vkey},
         monitor::{self, MonitorHandle},
@@ -789,9 +789,9 @@ fn update_modifiers<T>(window: HWND, userdata: &WindowData<T>) {
 }
 
 #[cfg(target_arch = "x86_64")]
-type WindowLongPtr = LONG_PTR;
+pub(crate) type WindowLongPtr = LONG_PTR;
 #[cfg(target_arch = "x86")]
-type WindowLongPtr = LONG;
+pub(crate) type WindowLongPtr = LONG;
 
 /// Any window whose callback is configured to this function will have its events propagated
 /// through the events loop of the thread the window was created in.
@@ -813,23 +813,27 @@ pub(super) unsafe extern "system" fn public_window_callback<T: 'static>(
             let initdata = createstruct.lpCreateParams as LONG_PTR;
             let initdata = &mut *(initdata as *mut InitData<'_, T>);
 
-            let runner = initdata.event_loop.runner_shared.clone();
-            if let Some((win, userdata)) = runner.catch_unwind(|| (initdata.post_init)(window)) {
-                initdata.window = Some(win);
-                let userdata = Box::into_raw(Box::new(userdata));
-                winuser::SetWindowLongPtrW(
-                    window,
-                    winuser::GWL_USERDATA,
-                    userdata as WindowLongPtr,
-                );
-                userdata
-            } else {
-                return -1;
-            }
+            let result = match initdata.on_nccreate(window) {
+                Some(userdata) => {
+                    winuser::SetWindowLongPtrW(window, winuser::GWL_USERDATA, userdata as _);
+                    winuser::DefWindowProcW(window, msg, wparam, lparam)
+                }
+                None => -1, // failed to create the window
+            };
+
+            return result;
         }
         // Getting here should quite frankly be impossible,
         // but we'll make window creation fail here just in case.
         (0, winuser::WM_CREATE) => return -1,
+        (_, winuser::WM_CREATE) => {
+            let createstruct = &mut *(lparam as *mut winuser::CREATESTRUCTW);
+            let initdata = createstruct.lpCreateParams as LONG_PTR;
+            let initdata = &mut *(initdata as *mut InitData<'_, T>);
+
+            initdata.on_create();
+            return winuser::DefWindowProcW(window, msg, wparam, lparam);
+        }
         (0, _) => return winuser::DefWindowProcW(window, msg, wparam, lparam),
         _ => userdata as *mut WindowData<T>,
     };
@@ -889,11 +893,6 @@ unsafe fn public_window_callback_inner<T: 'static>(
             0
         }
 
-        winuser::WM_NCCREATE => {
-            enable_non_client_dpi_scaling(window);
-            winuser::DefWindowProcW(window, msg, wparam, lparam)
-        }
-
         winuser::WM_NCLBUTTONDOWN => {
             if wparam == winuser::HTCAPTION as _ {
                 winuser::PostMessageW(window, winuser::WM_MOUSEMOVE, 0, lparam);