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/*
* Copyright (C) 2014 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "WheelEventDeltaTracker.h"
#include "PlatformWheelEvent.h"
namespace WebCore {
WheelEventDeltaTracker::WheelEventDeltaTracker()
: m_isTrackingDeltas(false)
{
}
WheelEventDeltaTracker::~WheelEventDeltaTracker()
{
}
void WheelEventDeltaTracker::beginTrackingDeltas()
{
m_recentWheelEventDeltas.clear();
m_isTrackingDeltas = true;
}
void WheelEventDeltaTracker::endTrackingDeltas()
{
m_isTrackingDeltas = false;
}
void WheelEventDeltaTracker::recordWheelEventDelta(const PlatformWheelEvent& event)
{
m_recentWheelEventDeltas.append(FloatSize(event.deltaX(), event.deltaY()));
if (m_recentWheelEventDeltas.size() > recentEventCount)
m_recentWheelEventDeltas.removeFirst();
}
static bool deltaIsPredominantlyVertical(const FloatSize& delta)
{
return fabs(delta.height()) > fabs(delta.width());
}
DominantScrollGestureDirection WheelEventDeltaTracker::dominantScrollGestureDirection() const
{
bool allVertical = m_recentWheelEventDeltas.size();
bool allHorizontal = m_recentWheelEventDeltas.size();
for (const auto& delta : m_recentWheelEventDeltas) {
bool isVertical = deltaIsPredominantlyVertical(delta);
allVertical &= isVertical;
allHorizontal &= !isVertical;
}
if (allVertical)
return DominantScrollGestureDirection::Vertical;
if (allHorizontal)
return DominantScrollGestureDirection::Horizontal;
return DominantScrollGestureDirection::None;
}
} // namespace WebCore
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