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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 "QtPanGestureRecognizer.h"
#include "QtWebPageEventHandler.h"
#include <QTouchEvent>
namespace WebKit {
QtPanGestureRecognizer::QtPanGestureRecognizer(QtWebPageEventHandler* eventHandler)
: QtGestureRecognizer(eventHandler)
{
reset();
}
bool QtPanGestureRecognizer::recognize(const QTouchEvent* event)
{
if (!interactionEngine())
return false;
// Pan gesture always starts on TouchBegin unless the engine is suspended, or
// we ignored the event.
if (m_state == NoGesture && event->type() != QEvent::TouchBegin)
return false;
// Having multiple touch points cancel the panning gesture.
if (event->touchPoints().size() > 1) {
if (m_state == GestureRecognized)
interactionEngine()->panGestureCancelled();
reset();
return false;
}
const QTouchEvent::TouchPoint& touchPoint = event->touchPoints().first();
switch (event->type()) {
case QEvent::TouchBegin:
ASSERT(m_state == NoGesture);
m_state = GestureRecognitionStarted;
m_firstPosition = touchPoint.screenPos();
m_touchBegin.reset(new QTouchEvent(*event));
interactionEngine()->panGestureCancelled();
return false;
case QEvent::TouchUpdate: {
ASSERT(m_state != NoGesture);
if (m_state == GestureRecognitionStarted) {
// To start the gesture, the delta from start in screen coordinates
// must be bigger than the trigger threshold.
QPointF totalOffsetFromStart(touchPoint.screenPos() - m_firstPosition);
if (qAbs(totalOffsetFromStart.x()) < panningInitialTriggerDistanceThreshold && qAbs(totalOffsetFromStart.y()) < panningInitialTriggerDistanceThreshold)
return false;
m_state = GestureRecognized;
ASSERT(m_touchBegin);
interactionEngine()->panGestureStarted(m_touchBegin.data());
}
ASSERT(m_state == GestureRecognized);
interactionEngine()->panGestureRequestUpdate(event);
return true;
}
case QEvent::TouchEnd:
if (m_state == GestureRecognized) {
interactionEngine()->panGestureEnded(event);
reset();
return true;
}
ASSERT(m_state == GestureRecognitionStarted);
reset();
return false;
default:
ASSERT_NOT_REACHED();
}
return false;
}
void QtPanGestureRecognizer::reset()
{
QtGestureRecognizer::reset();
m_firstPosition = QPointF();
}
} // namespace WebKit
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