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, 33 insertions, 0 deletions

diff --git a/tests/auto/gui/kernel/qguiapplication/tst_qguiapplication.cpp b/tests/auto/gui/kernel/qguiapplication/tst_qguiapplication.cpp
index 2a2dbd0e48..e4f1158d27 100644
--- a/tests/auto/gui/kernel/qguiapplication/tst_qguiapplication.cpp
+++ b/tests/auto/gui/kernel/qguiapplication/tst_qguiapplication.cpp
@@ -61,6 +61,8 @@ private slots:
 
     void staticFunctions();
 
+    void topLevelAt();
+
     void settableStyleHints_data();
     void settableStyleHints(); // Needs to run last as it changes style hints.
 };
@@ -1325,6 +1327,37 @@ void tst_QGuiApplication::staticFunctions()
     QPixmap::defaultDepth();
 }
 
+void tst_QGuiApplication::topLevelAt()
+{
+    int argc = 1;
+    char *argv[] = { const_cast<char*>("tst_qguiapplication") };
+    QGuiApplication app(argc, argv);
+
+    QWindow bottom;
+    bottom.setObjectName("Bottom");
+    bottom.setFlag(Qt::FramelessWindowHint);
+    bottom.setGeometry(200, 200, 200, 200);
+    bottom.showNormal();
+    QVERIFY(QTest::qWaitForWindowExposed(&bottom));
+    QTRY_COMPARE(app.topLevelAt(QPoint(300, 300)), &bottom);
+
+    QWindow top;
+    top.setObjectName("Top");
+    top.setFlag(Qt::FramelessWindowHint);
+    top.setGeometry(200, 200, 200, 200);
+    top.showNormal();
+    QVERIFY(QTest::qWaitForWindowExposed(&top));
+    top.raise();
+    QTRY_COMPARE(app.topLevelAt(QPoint(300, 300)), &top);
+
+    if (!QGuiApplicationPrivate::platformIntegration()->hasCapability(QPlatformIntegration::WindowMasks))
+        QSKIP("QWindow::setMask() is not supported.");
+
+    top.setMask(QRect(0, 0, 50, 50));
+    QTRY_COMPARE(app.topLevelAt(QPoint(300, 300)), &bottom);
+    QTRY_COMPARE(app.topLevelAt(QPoint(225, 225)), &top);
+}
+
 void tst_QGuiApplication::settableStyleHints_data()
 {
     QTest::addColumn<bool>("appInstance");