Add QPlatformWindow::isForeignWindow()

Simplifies code at call sites and allows for refactoring how to decide
if a window is foreign or not at a later point.

Change-Id: Icc51a83bac187f4975535366b53b4990832b6c82
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index 008b2a0d77..2c85ed3c0b 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -2161,11 +2161,14 @@ QWidget *qt_tlw_for_window(QWindow *wnd)
     // QTBUG-32177, wnd might be a QQuickView embedded via window container.
     while (wnd && !wnd->isTopLevel()) {
         QWindow *parent = wnd->parent();
+        if (!parent)
+            break;
+
         // Don't end up in windows not belonging to this application
-        if (parent && parent->type() != Qt::ForeignWindow)
-            wnd = wnd->parent();
-        else
+        if (parent->handle() && parent->handle()->isForeignWindow())
             break;
+
+        wnd = wnd->parent();
     }
     if (wnd) {
         const auto tlws = qApp->topLevelWidgets();