bool QtViewportInteractionEngine::panGestureActive() const
{
    QScroller* scroller = const_cast<QtViewportInteractionEngine*>(this)->scroller();
    return scroller->state() == QScroller::Pressed || scroller->state() == QScroller::Dragging;
}
bool QtViewportInteractionEngine::scrollAnimationActive() const
{
    QScroller* scroller = const_cast<QtViewportInteractionEngine*>(this)->scroller();
    return scroller->state() == QScroller::Scrolling;
}