QWidget: close the QWindow in QWidget::close

We want to close the window, end full screen mode on macOS, and free
platform resources. This is all done by QWindow::close. QWindow::close
closes the platform window, triggering a closeEvent to QWidgetWindow,
which then calls QWidgetPrivate::close_helper.

This way, closing a window via QWidget::close, QWindow::close, or
interactively by the user are all equivalent.

The QCloseEvent generated by the widget needs to be spontaneous for
window-system generated events (i.e. the user clicked the close button),
and non-spontaneous if the window closes because of a call to
QWindow::close. To keep track of whether the event originated in an
explicit call to QWindow::close, add a boolean to the QWindowPrivate.

Add a test case that verifies that the window resources is destroyed,
and that events are delivered as they should.

Done-with: Morten Johan Sørvig <morten.sorvig@qt.io>
Fixes: QTBUG-46701
Pick-to: 6.2
Change-Id: Iacb6a2c8d5e880b16b0c8f0c9257ed94bed36f5b
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 66 insertions, 0 deletions

diff --git a/tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp b/tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp
index dbd541c736..6d6affa23a 100644
--- a/tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp
+++ b/tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp
@@ -90,6 +90,8 @@ private slots:
     void tst_show_resize();
     void tst_show_resize_hide_show();
 
+    void close();
+
     void tst_windowFilePathAndwindowTitle_data();
     void tst_windowFilePathAndwindowTitle();
     void tst_windowFilePath_data();
@@ -247,6 +249,70 @@ void tst_QWidget_window::tst_show_resize_hide_show()
     QCOMPARE(w.size(), m_testWidgetSize);
 }
 
+void tst_QWidget_window::close()
+{
+    // Verfy that closing a QWidgetWindow deletes its platform window,
+    // as expected of a QWindow subclass. This must be done also
+    // if QWidget API is used to close. The QCloseEvent must not be
+    // spontaneous if the close is triggered by a Qt API that the application
+    // would call in response to an event, and spontaneous if it is directly
+    // caused by user interaction, such as clicking the (x) in the titlebar.
+    // We can simulate this only by generating a WindowSystemEvent.
+    // Children of the window should get a hide event (never spontaneous when
+    // caused by closing the window).
+
+    struct Widget : public QWidget
+    {
+        using QWidget::QWidget;
+        int spontClose = -1;
+        int spontHide = -1;
+    protected:
+        void hideEvent(QHideEvent *e)
+        { spontHide = e->spontaneous() ? 1 : 0; }
+        void closeEvent(QCloseEvent *e)
+        { spontClose = e->spontaneous() ? 1 : 0; }
+    };
+
+    // QWindow::close()
+    {
+        Widget w;
+        Widget child(&w);
+        w.winId();
+        QVERIFY(w.windowHandle());
+        QVERIFY(w.windowHandle()->handle());
+        w.windowHandle()->close();
+        QCOMPARE(w.spontClose, 0);
+        QCOMPARE(child.spontHide, -1); // was never shown
+        QVERIFY(w.windowHandle());
+        QVERIFY(!w.windowHandle()->handle());
+    }
+
+    // QWidget::close()
+    {
+        Widget w;
+        Widget child(&w);
+        w.show();
+        QVERIFY(w.windowHandle());
+        QVERIFY(w.windowHandle()->handle());
+        w.close();
+        QCOMPARE(w.spontClose, 0);
+        QCOMPARE(child.spontHide, 0);
+        QVERIFY(w.windowHandle());
+        QVERIFY(!w.windowHandle()->handle());
+    }
+
+    // User-initiated close
+    {
+        Widget w;
+        Widget child(&w);
+        w.show();
+        QWindowSystemInterface::handleCloseEvent(w.windowHandle());
+        QApplication::processEvents();
+        QCOMPARE(w.spontClose, 1);
+        QCOMPARE(child.spontHide, 0);
+    }
+}
+
 class PaintTestWidget : public QWidget
 {
 public: