QGesture: make sure we copy timestamp value for event clones

Otherwise, double-click recognition will fail.

Use QEvent::clone when possible, or set the timestamp explicitly when
not.

As a drive-by, remove some long-dead code in affected code lines.

Fixes: QTBUG-102010
Change-Id: I882bf6e8090bf6f182b7a0a3c62aa3a4c8db2e14
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
(cherry picked from commit fb09c82a2c7c44d41a0a36d8fe6d6d22e792668a)
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/widgets/util/qflickgesture.cpp

@@ -38,43 +38,19 @@ static QMouseEvent *copyMouseEvent(QEvent *e)
     case QEvent::MouseButtonPress:
     case QEvent::MouseButtonRelease:
     case QEvent::MouseMove: {
-        QMouseEvent *me = static_cast<QMouseEvent *>(e);
+        return static_cast<QMouseEvent *>(e->clone());
-        QMouseEvent *cme = new QMouseEvent(me->type(), QPoint(0, 0), me->scenePosition(), me->globalPosition(),
-                                           me->button(), me->buttons(), me->modifiers(), me->source());
-        return cme;
     }
 #if QT_CONFIG(graphicsview)
     case QEvent::GraphicsSceneMousePress:
     case QEvent::GraphicsSceneMouseRelease:
     case QEvent::GraphicsSceneMouseMove: {
         QGraphicsSceneMouseEvent *me = static_cast<QGraphicsSceneMouseEvent *>(e);
-#if 1
         QEvent::Type met = me->type() == QEvent::GraphicsSceneMousePress ? QEvent::MouseButtonPress :
                            (me->type() == QEvent::GraphicsSceneMouseRelease ? QEvent::MouseButtonRelease : QEvent::MouseMove);
         QMouseEvent *cme = new QMouseEvent(met, QPoint(0, 0), QPoint(0, 0), me->screenPos(),
                                            me->button(), me->buttons(), me->modifiers(), me->source());
+        cme->setTimestamp(me->timestamp());
         return cme;
-#else
-        QGraphicsSceneMouseEvent *copy = new QGraphicsSceneMouseEvent(me->type());
-        copy->setPos(me->pos());
-        copy->setScenePos(me->scenePos());
-        copy->setScreenPos(me->screenPos());
-        for (int i = 0x1; i <= 0x10; i <<= 1) {
-            Qt::MouseButton button = Qt::MouseButton(i);
-            copy->setButtonDownPos(button, me->buttonDownPos(button));
-            copy->setButtonDownScenePos(button, me->buttonDownScenePos(button));
-            copy->setButtonDownScreenPos(button, me->buttonDownScreenPos(button));
-        }
-        copy->setLastPos(me->lastPos());
-        copy->setLastScenePos(me->lastScenePos());
-        copy->setLastScreenPos(me->lastScreenPos());
-        copy->setButtons(me->buttons());
-        copy->setButton(me->button());
-        copy->setModifiers(me->modifiers());
-        copy->setSource(me->source());
-        copy->setFlags(me->flags());
-        return copy;
-#endif
     }
 #endif // QT_CONFIG(graphicsview)
     default:
@@ -190,22 +166,6 @@ public:
             mouseTarget = nullptr;
         } else if (mouseTarget) {
             // we did send a press, so we need to fake a release now
-
-            // release all pressed mouse buttons
-            /* Qt::MouseButtons mouseButtons = QGuiApplication::mouseButtons();
-            for (int i = 0; i < 32; ++i) {
-                if (mouseButtons & (1 << i)) {
-                    Qt::MouseButton b = static_cast<Qt::MouseButton>(1 << i);
-                    mouseButtons &= ~b;
-                    QPoint farFarAway(-QWIDGETSIZE_MAX, -QWIDGETSIZE_MAX);
-
-                    qFGDebug() << "QFG: sending a fake mouse release at far-far-away to " << mouseTarget;
-                    QMouseEvent re(QEvent::MouseButtonRelease, QPoint(), farFarAway,
-                                   b, mouseButtons, QGuiApplication::keyboardModifiers());
-                    sendMouseEvent(&re);
-                }
-            }*/
-
             QPoint farFarAway(-QWIDGETSIZE_MAX, -QWIDGETSIZE_MAX);
 
             qFGDebug() << "QFG: sending a fake mouse release at far-far-away to " << mouseTarget;
@@ -265,6 +225,7 @@ protected:
                                  mouseTarget->topLevelWidget()->mapFromGlobal(me->globalPosition()), me->globalPosition(),
                                  me->button(), me->buttons(), me->modifiers(),
                                  me->source(), me->pointingDevice());
+                copy.setTimestamp(me->timestamp());
                 qt_sendSpontaneousEvent(mouseTarget, &copy);
             }
 

tests/auto/widgets/util/qscroller/tst_qscroller.cpp

@@ -103,6 +103,7 @@ private slots:
     void scroll();
     void overshoot();
     void multipleWindows();
+    void mouseEventTimestamp();
 
 private:
     QPointingDevice *m_touchScreen = QTest::createTouchDevice();
@@ -516,6 +517,67 @@ void tst_QScroller::multipleWindows()
 #endif
 }
 
+/*!
+    This test verifies that mouse events arrive at the target widget
+    with valid timestamp, even if there is a gesture filtering (and then
+    replaying a copy of) the event. QTBUG-102010
+
+    We cannot truly simulate the double click here, as simulated events don't
+    go through the exact same event machinery as real events, so double clicks
+    don't get generated by Qt here. But we can verify that the timestamps of
+    the eventually delivered events are maintained.
+*/
+void tst_QScroller::mouseEventTimestamp()
+{
+#if QT_CONFIG(gestures) && QT_CONFIG(scroller)
+    QScopedPointer<tst_QScrollerWidget> sw(new tst_QScrollerWidget());
+    sw->scrollArea = QRectF(0, 0, 1000, 1000);
+    QScroller::grabGesture(sw.data(), QScroller::LeftMouseButtonGesture);
+    sw->setGeometry(100, 100, 400, 300);
+    sw->show();
+    QApplication::setActiveWindow(sw.data());
+    if (!QTest::qWaitForWindowExposed(sw.data()) || !QTest::qWaitForWindowActive(sw.data()))
+        QSKIP("Failed to show and activate window");
+
+    QScroller *s1 = QScroller::scroller(sw.data());
+
+    struct EventFilter : QObject
+    {
+        QList<int> timestamps;
+    protected:
+        bool eventFilter(QObject *o, QEvent *e) override
+        {
+            if (e->isInputEvent())
+                timestamps << static_cast<QInputEvent *>(e)->timestamp();
+            return QObject::eventFilter(o, e);
+        }
+
+    } eventFilter;
+    sw->installEventFilter(&eventFilter);
+
+    const int interval = QGuiApplication::styleHints()->mouseDoubleClickInterval() / 10;
+    const QPoint point = sw->geometry().center();
+    // Simulate double by pressing twice within the double click interval.
+    // Presses are filtered and then delayed by the scroller/gesture machinery,
+    // so we first record all events, and then make sure that the relative timestamps
+    // are maintained also for the replayed or synthesized events.
+    QTest::mousePress(sw->windowHandle(), Qt::LeftButton, {}, point);
+    QCOMPARE(s1->state(), QScroller::Pressed);
+    QTest::mouseRelease(sw->windowHandle(), Qt::LeftButton, {}, point, interval);
+    QCOMPARE(s1->state(), QScroller::Inactive);
+    QTest::mousePress(sw->windowHandle(), Qt::LeftButton, {}, point, interval);
+    QCOMPARE(s1->state(), QScroller::Pressed);
+    // also filtered and delayed by the scroller
+    QTest::mouseRelease(sw->windowHandle(), Qt::LeftButton, {}, point, interval);
+    QCOMPARE(s1->state(), QScroller::Inactive);
+    int lastTimestamp = -1;
+    for (int timestamp : std::as_const(eventFilter.timestamps)) {
+        QCOMPARE_GE(timestamp, lastTimestamp);
+        lastTimestamp = timestamp + interval;
+    }
+#endif
+}
+
 QTEST_MAIN(tst_QScroller)
 
 #include "tst_qscroller.moc"