QAccessibleWidget: Retrieve window from native parent widget.

Query the native parent widget if the widget does not have a window handle.
The window is required to be able to determine the correct
scale factor for the screen when High DPI scaling is active.

Change-Id: Ibaf5e8e7b07327ea635d2f726acea76c2c95bda3
Task-number: QTBUG-52943
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@theqtcompany.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/src/widgets/accessible/qaccessiblewidget.cpp b/src/widgets/accessible/qaccessiblewidget.cpp
index 3a9422cc26..beff27ad64 100644
--- a/src/widgets/accessible/qaccessiblewidget.cpp
+++ b/src/widgets/accessible/qaccessiblewidget.cpp
@@ -206,8 +206,14 @@ bool QAccessibleWidget::isValid() const
 /*! \reimp */
 QWindow *QAccessibleWidget::window() const
 {
-    Q_ASSERT(widget());
-    return widget()->windowHandle();
+    const QWidget *w = widget();
+    Q_ASSERT(w);
+    QWindow *result = w->windowHandle();
+    if (!result) {
+        if (const QWidget *nativeParent = w->nativeParentWidget())
+            result = nativeParent->windowHandle();
+    }
+    return result;
 }
 
 /*!