ScrollResult ScrollableArea::handleWheel(const PlatformWheelEvent& wheelEvent)
{
    // Wheel events which do not scroll are used to trigger zooming.
    if (!wheelEvent.canScroll())
        return ScrollResult();

    cancelProgrammaticScrollAnimation();
    return scrollAnimator()->handleWheelEvent(wheelEvent);
}
Exemplo n.º 2
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PassRefPtrWillBeRawPtr<WheelEvent> WheelEvent::create(const PlatformWheelEvent& event, PassRefPtrWillBeRawPtr<AbstractView> view)
{
    return adoptRefWillBeNoop(new WheelEvent(FloatPoint(event.wheelTicksX(), event.wheelTicksY()), FloatPoint(event.deltaX(), event.deltaY()),
        convertDeltaMode(event), view, event.globalPosition(), event.position(),
        event.ctrlKey(), event.altKey(), event.shiftKey(), event.metaKey(),
        MouseEvent::platformModifiersToButtons(event.modifiers()),
        event.canScroll(), event.hasPreciseScrollingDeltas(),
        static_cast<Event::RailsMode>(event.railsMode())));
}
ScrollResult RootFrameViewport::handleWheel(const PlatformWheelEvent& event)
{
    updateScrollAnimator();

    ScrollableArea& primary = !m_invertScrollOrder ? layoutViewport() : visualViewport();
    ScrollableArea& secondary = !m_invertScrollOrder ? visualViewport() : layoutViewport();

    ScrollResult viewScrollResult = primary.handleWheel(event);

    // The visual viewport will only accept pixel scrolls.
    if (!event.canScroll() || event.granularity() == ScrollByPageWheelEvent)
        return viewScrollResult;

    // TODO(sataya.m) : The delta in PlatformWheelEvent is negative when scrolling the
    // wheel towards the user, so negate it to get the scroll delta that should be applied
    // to the page. unusedScrollDelta computed in the ScrollResult is also negative. Say
    // there is WheelEvent({0, -10} and page scroll by 2px and unusedScrollDelta computed
    // is {0, -8}. Due to which we have to negate the unusedScrollDelta to obtain the expected
    // animation.Please address http://crbug.com/504389.
    DoublePoint oldOffset = secondary.scrollPositionDouble();
    DoublePoint locationDelta;
    if (viewScrollResult.didScroll()) {
        locationDelta = -DoublePoint(viewScrollResult.unusedScrollDeltaX, viewScrollResult.unusedScrollDeltaY);
    } else {
        if (event.railsMode() != PlatformEvent::RailsModeVertical)
            locationDelta.setX(-event.deltaX());
        if (event.railsMode() != PlatformEvent::RailsModeHorizontal)
            locationDelta.setY(-event.deltaY());
    }

    DoublePoint targetPosition = secondary.clampScrollPosition(
        secondary.scrollPositionDouble() + toDoubleSize(locationDelta));
    secondary.setScrollPosition(targetPosition, UserScroll);

    DoublePoint usedLocationDelta(secondary.scrollPositionDouble() - oldOffset);

    bool didScrollX = viewScrollResult.didScrollX || usedLocationDelta.x();
    bool didScrollY = viewScrollResult.didScrollY || usedLocationDelta.y();
    return ScrollResult(didScrollX, didScrollY, -viewScrollResult.unusedScrollDeltaX - usedLocationDelta.x(), -viewScrollResult.unusedScrollDeltaY - usedLocationDelta.y());
}