macOS: Take window mask into account when computing QCocoaScreen::topLevelAt

Although not explicitly documented, this is the behavior in practice
on XCB and Windows, and we rely on this behavior in our implementation
of QApplication::widgetAt(), where we punch a temporary hole in the
widget using a mask if it has Qt::WA_TransparentForMouseEvents set.

Pick-to: 6.5 6.6
Fixes: QTBUG-41696
Task-number: QTBUG-119092
Change-Id: Ie7abc31b6930ee6b56fcdf391befc625c1ddf502
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoascreen.mm b/src/plugins/platforms/cocoa/qcocoascreen.mm
index 7f1995761a..966b412de3 100644
--- a/src/plugins/platforms/cocoa/qcocoascreen.mm
+++ b/src/plugins/platforms/cocoa/qcocoascreen.mm
@@ -542,7 +542,12 @@ QWindow *QCocoaScreen::topLevelAt(const QPoint &point) const
             if (!w->isVisible())
                 return;
 
-            if (!QHighDpi::toNativePixels(w->geometry(), w).contains(point))
+            auto nativeGeometry = QHighDpi::toNativePixels(w->geometry(), w);
+            if (!nativeGeometry.contains(point))
+                return;
+
+            QRegion mask = QHighDpi::toNativeLocalPosition(w->mask(), w);
+            if (!mask.isEmpty() && !mask.contains(point - nativeGeometry.topLeft()))
                 return;
 
             window = w;