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/*
* Copyright (C) 2011 Benjamin Poulain <benjamin@webkit.org>
*
* 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 "QtPinchGestureRecognizer.h"
#include "PageViewportControllerClientQt.h"
#include "QtWebPageEventHandler.h"
#include <QtCore/QLineF>
namespace WebKit {
const qreal pinchInitialTriggerDistanceThreshold = 5.;
static inline QPointF computePinchCenter(const QTouchEvent::TouchPoint& point1, const QTouchEvent::TouchPoint& point2)
{
return (point1.pos() + point2.pos()) / 2.0f;
}
QtPinchGestureRecognizer::QtPinchGestureRecognizer(QtWebPageEventHandler* eventHandler)
: QtGestureRecognizer(eventHandler)
{
reset();
}
bool QtPinchGestureRecognizer::update(const QTouchEvent::TouchPoint& point1, const QTouchEvent::TouchPoint& point2)
{
const qreal currentFingerDistance = QLineF(point1.screenPos(), point2.screenPos()).length();
switch (m_state) {
case NoGesture:
m_initialFingerDistance = currentFingerDistance;
m_state = GestureRecognitionStarted;
return false;
case GestureRecognitionStarted: {
const qreal pinchDistance = qAbs(currentFingerDistance - m_initialFingerDistance);
if (pinchDistance < pinchInitialTriggerDistanceThreshold)
return false;
m_state = GestureRecognized;
if (viewportController())
viewportController()->pinchGestureStarted(computePinchCenter(point1, point2));
// We reset the initial span distance to the current distance of the
// touch points in order to avoid the jump caused by the events which
// were skipped between the recognition start and the actual recognition.
m_initialFingerDistance = currentFingerDistance;
// fall through
}
case GestureRecognized:
const qreal totalScaleFactor = currentFingerDistance / m_initialFingerDistance;
const QPointF touchCenterInViewCoordinates = computePinchCenter(point1, point2);
if (viewportController())
viewportController()->pinchGestureRequestUpdate(touchCenterInViewCoordinates, totalScaleFactor);
return true;
break;
}
ASSERT_NOT_REACHED();
return false;
}
void QtPinchGestureRecognizer::finish()
{
if (m_state == NoGesture)
return;
if (viewportController())
viewportController()->pinchGestureEnded();
reset();
}
void QtPinchGestureRecognizer::cancel()
{
if (m_state == NoGesture)
return;
if (viewportController())
viewportController()->pinchGestureCancelled();
reset();
}
} // namespace WebKit
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