示例#1
0
bool scroll_widget::event(QEvent *a_event_ptr) {
  if (!o_scroll_widget->m_viewport) {
    return QGraphicsObject::event(a_event_ptr);
  }

  switch (a_event_ptr->type()) {
  case QScrollPrepareEvent::ScrollPrepare: {
    qDebug() << Q_FUNC_INFO << "Prepare :";
    QScrollPrepareEvent *se = static_cast<QScrollPrepareEvent *>(a_event_ptr);
    se->setViewportSize(o_scroll_widget->m_size);
    QRectF br = o_scroll_widget->m_viewport->boundingRect();
    se->setContentPosRange(QRectF(
        0, 0, qMax(qreal(0), br.width() - o_scroll_widget->m_size.width()),
        qMax(qreal(0), br.height() - o_scroll_widget->m_size.height())));
    se->setContentPos(-o_scroll_widget->m_viewport->pos());
    se->accept();
    return QGraphicsObject::event(a_event_ptr);
  }
  case QScrollEvent::Scroll: {
    qDebug() << Q_FUNC_INFO << "Scroll";
    QScrollEvent *se = static_cast<QScrollEvent *>(a_event_ptr);
    o_scroll_widget->m_viewport->setPos(-se->contentPos() -
                                        se->overshootDistance());
    return true;
  }

  default:
    break;
  }
  return QGraphicsObject::event(a_event_ptr);
}
bool QtViewportInteractionEngine::event(QEvent* event)
{
    switch (event->type()) {
    case QEvent::ScrollPrepare: {
        QScrollPrepareEvent* prepareEvent = static_cast<QScrollPrepareEvent*>(event);
        const QRectF viewportRect = m_viewport->boundingRect();
        const QRectF contentRect = m_viewport->mapRectFromItem(m_content, m_content->boundingRect());
        const QRectF posRange = computePosRangeForItemAtScale(m_content->contentsScale());
        prepareEvent->setContentPosRange(posRange);
        prepareEvent->setViewportSize(viewportRect.size());

        // As we want to push the contents and not actually scroll it, we need to invert the positions here.
        prepareEvent->setContentPos(-contentRect.topLeft());
        prepareEvent->accept();
        return true;
    }
    case QEvent::Scroll: {
        QScrollEvent* scrollEvent = static_cast<QScrollEvent*>(event);
        QPointF newPos = -scrollEvent->contentPos() - scrollEvent->overshootDistance();
        if (m_content->pos() != newPos) {
            QPointF currentPosInCSSCoordinates = m_viewport->mapToWebContent(m_content->pos());
            QPointF newPosInCSSCoordinates = m_viewport->mapToWebContent(newPos);

            // This must be emitted before viewportUpdateRequested so that the web process knows where to look for tiles.
            emit viewportTrajectoryVectorChanged(currentPosInCSSCoordinates - newPosInCSSCoordinates);
            m_content->setPos(newPos);
        }
        return true;
    }
    default:
        break;
    }
    return QObject::event(event);
}
示例#3
0
bool PlotWidget::eventFilter(QObject *obj, QEvent *ev)
{
    if (ev->type() == QEvent::Scroll) {
        QScrollEvent *se = static_cast<QScrollEvent *>(ev);
        QScroller *scroller = QScroller::scroller(m_widget);

        QPointF v = scroller->velocity();
        //v.rx() *= scroller->pixelPerMeter().x();
        //v.ry() *= scroller->pixelPerMeter().y();

        PlotItem pi = { v, se->contentPos(), se->overshootDistance() };
        addPlotItem(pi);
    }

    return QWidget::eventFilter(obj, ev);
}