void ScrollAnimator::handleWheelEvent(PlatformWheelEvent& e)
{
Scrollbar* horizontalScrollbar = m_scrollableArea->horizontalScrollbar();
Scrollbar* verticalScrollbar = m_scrollableArea->verticalScrollbar();
// Accept the event if we have a scrollbar in that direction and can still
// scroll any further.
float deltaX = horizontalScrollbar ? e.deltaX() : 0;
float deltaY = verticalScrollbar ? e.deltaY() : 0;
IntSize maxForwardScrollDelta = m_scrollableArea->maximumScrollPosition() - m_scrollableArea->scrollPosition();
IntSize maxBackwardScrollDelta = m_scrollableArea->scrollPosition() - m_scrollableArea->minimumScrollPosition();
if ((deltaX < 0 && maxForwardScrollDelta.width() > 0)
|| (deltaX > 0 && maxBackwardScrollDelta.width() > 0)
|| (deltaY < 0 && maxForwardScrollDelta.height() > 0)
|| (deltaY > 0 && maxBackwardScrollDelta.height() > 0)) {
e.accept();
if (e.granularity() == ScrollByPageWheelEvent) {
ASSERT(!e.deltaX());
bool negative = deltaY < 0;
deltaY = max(max(static_cast<float>(m_scrollableArea->visibleHeight()) * Scrollbar::minFractionToStepWhenPaging(), static_cast<float>(m_scrollableArea->visibleHeight() - Scrollbar::maxOverlapBetweenPages())), 1.0f);
if (negative)
deltaY = -deltaY;
}
if (deltaY)
scroll(VerticalScrollbar, ScrollByPixel, verticalScrollbar->pixelStep(), -deltaY);
if (deltaX)
scroll(HorizontalScrollbar, ScrollByPixel, horizontalScrollbar->pixelStep(), -deltaX);
}
}
bool ScrollAnimator::handleWheelEvent(const PlatformWheelEvent& e)
{
#if ENABLE(CSS_SCROLL_SNAP) && PLATFORM(MAC)
if (!m_scrollController.processWheelEventForScrollSnap(e))
return false;
#endif
#if PLATFORM(COCOA)
// Events in the PlatformWheelEventPhaseMayBegin phase have no deltas, and therefore never passes through the scroll handling logic below.
// This causes us to return with an 'unhandled' return state, even though this event was successfully processed.
//
// We receive at least one PlatformWheelEventPhaseMayBegin when starting main-thread scrolling (see FrameView::wheelEvent), which can
// fool the scrolling thread into attempting to handle the scroll, unless we treat the event as handled here.
if (e.phase() == PlatformWheelEventPhaseMayBegin)
return true;
#endif
Scrollbar* horizontalScrollbar = m_scrollableArea.horizontalScrollbar();
Scrollbar* verticalScrollbar = m_scrollableArea.verticalScrollbar();
// Accept the event if we have a scrollbar in that direction and can still
// scroll any further.
float deltaX = horizontalScrollbar ? e.deltaX() : 0;
float deltaY = verticalScrollbar ? e.deltaY() : 0;
bool handled = false;
ScrollGranularity granularity = ScrollByPixel;
IntSize maxForwardScrollDelta = m_scrollableArea.maximumScrollPosition() - m_scrollableArea.scrollPosition();
IntSize maxBackwardScrollDelta = m_scrollableArea.scrollPosition() - m_scrollableArea.minimumScrollPosition();
if ((deltaX < 0 && maxForwardScrollDelta.width() > 0)
|| (deltaX > 0 && maxBackwardScrollDelta.width() > 0)
|| (deltaY < 0 && maxForwardScrollDelta.height() > 0)
|| (deltaY > 0 && maxBackwardScrollDelta.height() > 0)) {
handled = true;
if (deltaY) {
if (e.granularity() == ScrollByPageWheelEvent) {
bool negative = deltaY < 0;
deltaY = Scrollbar::pageStepDelta(m_scrollableArea.visibleHeight());
if (negative)
deltaY = -deltaY;
}
scroll(VerticalScrollbar, granularity, verticalScrollbar->pixelStep(), -deltaY);
}
if (deltaX) {
if (e.granularity() == ScrollByPageWheelEvent) {
bool negative = deltaX < 0;
deltaX = Scrollbar::pageStepDelta(m_scrollableArea.visibleWidth());
if (negative)
deltaX = -deltaX;
}
scroll(HorizontalScrollbar, granularity, horizontalScrollbar->pixelStep(), -deltaX);
}
}
return handled;
}
bool ScrollAnimator::handleWheelEvent(const PlatformWheelEvent& e)
{
Scrollbar* horizontalScrollbar = m_scrollableArea->horizontalScrollbar();
Scrollbar* verticalScrollbar = m_scrollableArea->verticalScrollbar();
// Accept the event if we have a scrollbar in that direction and can still
// scroll any further.
float deltaX = horizontalScrollbar ? e.deltaX() : 0;
float deltaY = verticalScrollbar ? e.deltaY() : 0;
bool handled = false;
#if PLATFORM(CHROMIUM) && !OS(DARWIN)
ScrollGranularity granularity = e.hasPreciseScrollingDeltas() ? ScrollByPrecisePixel : ScrollByPixel;
#else
ScrollGranularity granularity = ScrollByPixel;
#endif
IntSize maxForwardScrollDelta = m_scrollableArea->maximumScrollPosition() - m_scrollableArea->scrollPosition();
IntSize maxBackwardScrollDelta = m_scrollableArea->scrollPosition() - m_scrollableArea->minimumScrollPosition();
if ((deltaX < 0 && maxForwardScrollDelta.width() > 0)
|| (deltaX > 0 && maxBackwardScrollDelta.width() > 0)
|| (deltaY < 0 && maxForwardScrollDelta.height() > 0)
|| (deltaY > 0 && maxBackwardScrollDelta.height() > 0)) {
handled = true;
if (deltaY) {
if (e.granularity() == ScrollByPageWheelEvent) {
bool negative = deltaY < 0;
deltaY = max(max(static_cast<float>(m_scrollableArea->visibleHeight()) * Scrollbar::minFractionToStepWhenPaging(), static_cast<float>(m_scrollableArea->visibleHeight() - Scrollbar::maxOverlapBetweenPages())), 1.0f);
if (negative)
deltaY = -deltaY;
}
scroll(VerticalScrollbar, granularity, verticalScrollbar->pixelStep(), -deltaY);
}
if (deltaX) {
if (e.granularity() == ScrollByPageWheelEvent) {
bool negative = deltaX < 0;
deltaX = max(max(static_cast<float>(m_scrollableArea->visibleWidth()) * Scrollbar::minFractionToStepWhenPaging(), static_cast<float>(m_scrollableArea->visibleWidth() - Scrollbar::maxOverlapBetweenPages())), 1.0f);
if (negative)
deltaX = -deltaX;
}
scroll(HorizontalScrollbar, granularity, horizontalScrollbar->pixelStep(), -deltaX);
}
}
return handled;
}
bool ScrollableArea::scroll(ScrollDirection direction, ScrollGranularity granularity, float multiplier)
{
ScrollbarOrientation orientation;
Scrollbar* scrollbar;
if (direction == ScrollUp || direction == ScrollDown) {
orientation = VerticalScrollbar;
scrollbar = verticalScrollbar();
} else {
orientation = HorizontalScrollbar;
scrollbar = horizontalScrollbar();
}
if (!scrollbar)
return false;
float step = 0;
switch (granularity) {
case ScrollByLine:
step = scrollbar->lineStep();
break;
case ScrollByPage:
step = scrollbar->pageStep();
break;
case ScrollByDocument:
step = scrollbar->totalSize();
break;
case ScrollByPixel:
case ScrollByPrecisePixel:
step = scrollbar->pixelStep();
break;
case ScrollByPixelVelocity:
break;
}
if (granularity != ScrollByPixelVelocity && (direction == ScrollUp || direction == ScrollLeft))
multiplier = -multiplier;
return scrollAnimator()->scroll(orientation, granularity, step, multiplier);
}