ScrollAnimator.cpp [plain text]
#include "config.h"
#include "ScrollAnimator.h"
#include "FloatPoint.h"
#include "LayoutSize.h"
#include "PlatformWheelEvent.h"
#include "ScrollableArea.h"
#include <algorithm>
namespace WebCore {
#if !ENABLE(SMOOTH_SCROLLING) && !PLATFORM(IOS)
std::unique_ptr<ScrollAnimator> ScrollAnimator::create(ScrollableArea& scrollableArea)
{
return std::make_unique<ScrollAnimator>(scrollableArea);
}
#endif
ScrollAnimator::ScrollAnimator(ScrollableArea& scrollableArea)
: m_scrollableArea(scrollableArea)
#if ENABLE(CSS_SCROLL_SNAP) || ENABLE(RUBBER_BANDING)
, m_scrollController(*this)
#endif
, m_currentPosX(0)
, m_currentPosY(0)
{
}
ScrollAnimator::~ScrollAnimator()
{
}
bool ScrollAnimator::scroll(ScrollbarOrientation orientation, ScrollGranularity, float step, float multiplier)
{
float* currentPos = (orientation == HorizontalScrollbar) ? &m_currentPosX : &m_currentPosY;
float newPos = std::max(std::min(*currentPos + (step * multiplier), static_cast<float>(m_scrollableArea.scrollSize(orientation))), 0.0f);
float delta = *currentPos - newPos;
if (*currentPos == newPos)
return false;
*currentPos = newPos;
notifyPositionChanged(orientation == HorizontalScrollbar ? FloatSize(delta, 0) : FloatSize(0, delta));
return true;
}
void ScrollAnimator::scrollToOffsetWithoutAnimation(const FloatPoint& offset)
{
FloatSize delta = FloatSize(offset.x() - m_currentPosX, offset.y() - m_currentPosY);
m_currentPosX = offset.x();
m_currentPosY = offset.y();
notifyPositionChanged(delta);
updateActiveScrollSnapIndexForOffset();
}
#if ENABLE(CSS_SCROLL_SNAP)
#if PLATFORM(MAC)
bool ScrollAnimator::processWheelEventForScrollSnap(const PlatformWheelEvent& wheelEvent)
{
return m_scrollController.processWheelEventForScrollSnap(wheelEvent);
}
#endif
bool ScrollAnimator::activeScrollSnapIndexDidChange() const
{
return m_scrollController.activeScrollSnapIndexDidChange();
}
unsigned ScrollAnimator::activeScrollSnapIndexForAxis(ScrollEventAxis axis) const
{
return m_scrollController.activeScrollSnapIndexForAxis(axis);
}
#endif
bool ScrollAnimator::handleWheelEvent(const PlatformWheelEvent& e)
{
#if ENABLE(CSS_SCROLL_SNAP) && PLATFORM(MAC)
if (!m_scrollController.processWheelEventForScrollSnap(e))
return false;
#endif
#if PLATFORM(COCOA)
if (e.phase() == PlatformWheelEventPhaseMayBegin)
return true;
#endif
Scrollbar* horizontalScrollbar = m_scrollableArea.horizontalScrollbar();
Scrollbar* verticalScrollbar = m_scrollableArea.verticalScrollbar();
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;
}
#if ENABLE(TOUCH_EVENTS)
bool ScrollAnimator::handleTouchEvent(const PlatformTouchEvent&)
{
return false;
}
#endif
void ScrollAnimator::setCurrentPosition(const FloatPoint& position)
{
m_currentPosX = position.x();
m_currentPosY = position.y();
updateActiveScrollSnapIndexForOffset();
}
FloatPoint ScrollAnimator::currentPosition() const
{
return FloatPoint(m_currentPosX, m_currentPosY);
}
void ScrollAnimator::updateActiveScrollSnapIndexForOffset()
{
#if ENABLE(CSS_SCROLL_SNAP)
m_scrollController.setActiveScrollSnapIndicesForOffset(m_currentPosX, m_currentPosY);
if (m_scrollController.activeScrollSnapIndexDidChange()) {
m_scrollableArea.setCurrentHorizontalSnapPointIndex(m_scrollController.activeScrollSnapIndexForAxis(ScrollEventAxis::Horizontal));
m_scrollableArea.setCurrentVerticalSnapPointIndex(m_scrollController.activeScrollSnapIndexForAxis(ScrollEventAxis::Vertical));
}
#endif
}
void ScrollAnimator::notifyPositionChanged(const FloatSize& delta)
{
UNUSED_PARAM(delta);
m_scrollableArea.setScrollOffsetFromAnimation(IntPoint(m_currentPosX, m_currentPosY));
}
#if ENABLE(CSS_SCROLL_SNAP)
void ScrollAnimator::updateScrollSnapState()
{
m_scrollController.updateScrollSnapState(m_scrollableArea);
}
LayoutUnit ScrollAnimator::scrollOffsetOnAxis(ScrollEventAxis axis) const
{
return axis == ScrollEventAxis::Horizontal ? m_currentPosX : m_currentPosY;
}
void ScrollAnimator::immediateScrollOnAxis(ScrollEventAxis axis, float delta)
{
FloatPoint currentPosition = this->currentPosition();
if (axis == ScrollEventAxis::Horizontal)
scrollToOffsetWithoutAnimation(FloatPoint(currentPosition.x() + delta, currentPosition.y()));
else
scrollToOffsetWithoutAnimation(FloatPoint(currentPosition.x(), currentPosition.y() + delta));
}
LayoutSize ScrollAnimator::scrollExtent() const
{
return m_scrollableArea.contentsSize();
}
#endif
#if (ENABLE(CSS_SCROLL_SNAP) || ENABLE(RUBBER_BANDING)) && PLATFORM(MAC)
void ScrollAnimator::deferTestsForReason(WheelEventTestTrigger::ScrollableAreaIdentifier identifier, WheelEventTestTrigger::DeferTestTriggerReason reason) const
{
if (!m_wheelEventTestTrigger)
return;
m_wheelEventTestTrigger->deferTestsForReason(identifier, reason);
}
void ScrollAnimator::removeTestDeferralForReason(WheelEventTestTrigger::ScrollableAreaIdentifier identifier, WheelEventTestTrigger::DeferTestTriggerReason reason) const
{
if (!m_wheelEventTestTrigger)
return;
m_wheelEventTestTrigger->removeTestDeferralForReason(identifier, reason);
}
#endif
}