Deliver WindowActivate/Deactivate events to QWindow

We need those events to trigger palette color group changes in QQuickItem
without having to connect every item to yet another QWindow signal.

Task-number: QTBUG-93752
Pick-to: 6.2
Change-Id: I8534808cdaab828e5876f8fda31567aeb1b4272a
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/gui/kernel/qguiapplication.cpp

@@ -3478,8 +3478,16 @@ void QGuiApplicationPrivate::notifyLayoutDirectionChange()
     }
 }
 
-void QGuiApplicationPrivate::notifyActiveWindowChange(QWindow *)
+void QGuiApplicationPrivate::notifyActiveWindowChange(QWindow *prev)
 {
+    if (prev) {
+        QEvent de(QEvent::WindowDeactivate);
+        QCoreApplication::sendEvent(prev, &de);
+    }
+    if (self->focus_window) {
+        QEvent ae(QEvent::WindowActivate);
+        QCoreApplication::sendEvent(focus_window, &ae);
+    }
 }
 
 /*!

src/widgets/kernel/qapplication.cpp

@@ -1921,6 +1921,7 @@ void QApplicationPrivate::notifyActiveWindowChange(QWindow *previous)
                 if (widget->inherits("QAxHostWidget"))
                     widget->setFocus(Qt::ActiveWindowFocusReason);
     }
+    // don't call base class to avoid double delivery of WindowActivate/Deactivate events
 }
 
 /*!internal

tests/auto/gui/kernel/qwindow/tst_qwindow.cpp

@@ -109,6 +109,7 @@ private slots:
     void testBlockingWindowShownAfterModalDialog();
     void generatedMouseMove();
     void keepPendingUpdateRequests();
+    void activateDeactivateEvent();
 
 private:
     QPoint m_availableTopLeft;
@@ -2604,6 +2605,48 @@ void tst_QWindow::keepPendingUpdateRequests()
     QTRY_VERIFY(!platformWindow->hasPendingUpdateRequest());
 }
 
+void tst_QWindow::activateDeactivateEvent()
+{
+    class Window : public QWindow
+    {
+    public:
+        using QWindow::QWindow;
+
+        int activateCount = 0;
+        int deactivateCount = 0;
+    protected:
+        bool event(QEvent *e)
+        {
+            switch (e->type()) {
+            case QEvent::WindowActivate:
+                ++activateCount;
+                break;
+            case QEvent::WindowDeactivate:
+                ++deactivateCount;
+                break;
+            default:
+                break;
+            }
+            return QWindow::event(e);
+        }
+    };
+
+    Window w1;
+    Window w2;
+
+    w1.show();
+    w1.requestActivate();
+    QVERIFY(QTest::qWaitForWindowActive(&w1));
+    QCOMPARE(w1.activateCount, 1);
+    QCOMPARE(w1.deactivateCount, 0);
+
+    w2.show();
+    w2.requestActivate();
+    QVERIFY(QTest::qWaitForWindowActive(&w2));
+    QCOMPARE(w1.deactivateCount, 1);
+    QCOMPARE(w2.activateCount, 1);
+}
+
 #include <tst_qwindow.moc>
 QTEST_MAIN(tst_QWindow)