Rémi Bernon : winex11: Force thread DPI awareness when calling NtUserChildWindowFromPointEx.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 0bc571657e63b478fb5913b90343a8ec39443b82
URL:    https://gitlab.winehq.org/wine/wine/-/commit/0bc571657e63b478fb5913b90343a8e...

Author: Rémi Bernon 
Date:   Mon Jun 10 11:36:12 2024 +0200

winex11: Force thread DPI awareness when calling NtUserChildWindowFromPointEx.

---

dlls/winex11.drv/event.c  | 3 +--
 dlls/winex11.drv/x11drv.h | 9 +++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/dlls/winex11.drv/event.c b/dlls/winex11.drv/event.c
index a0b46fe1fd9..c377bbc9984 100644
--- a/dlls/winex11.drv/event.c
+++ b/dlls/winex11.drv/event.c
@@ -1423,8 +1423,7 @@ static HWND find_drop_window( HWND hQueryWnd, LPPOINT lpPt )

if (PtInRect( &tempRect, pt))
         {
-            HWND ret = NtUserChildWindowFromPointEx( hQueryWnd, pt.x, pt.y,
-                                                     CWP_SKIPINVISIBLE|CWP_SKIPDISABLED );
+            HWND ret = child_window_from_point( hQueryWnd, pt.x, pt.y, CWP_SKIPINVISIBLE | CWP_SKIPDISABLED );
             if (ret && ret != hQueryWnd)
             {
                 ret = find_drop_window( ret, lpPt );
diff --git a/dlls/winex11.drv/x11drv.h b/dlls/winex11.drv/x11drv.h
index 3485d239fa2..6d257a2afbd 100644
--- a/dlls/winex11.drv/x11drv.h
+++ b/dlls/winex11.drv/x11drv.h
@@ -903,6 +903,15 @@ static inline BOOL redraw_window( HWND hwnd, const RECT *rect, HRGN hrgn, UINT f
     return ret;
 }

+/* per-monitor DPI aware NtUserChildWindowFromPointEx call */
+static inline HWND child_window_from_point( HWND parent, LONG x, LONG y, UINT flags )
+{
+    UINT context = NtUserSetThreadDpiAwarenessContext( NTUSER_DPI_PER_MONITOR_AWARE_V2 );
+    HWND ret = NtUserChildWindowFromPointEx( parent, x, y, flags );
+    NtUserSetThreadDpiAwarenessContext( context );
+    return ret;
+}
+
 static inline HWND get_focus(void)
 {
     GUITHREADINFO info;