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/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://www.qtsoftware.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/
#include "graphicsview.h"
#include <QScrollBar>
#include <QTouchEvent>
GraphicsView::GraphicsView(QGraphicsScene *scene, QWidget *parent)
: QGraphicsView(scene, parent)
{
setAttribute(Qt::WA_AcceptTouchEvents);
setDragMode(ScrollHandDrag);
}
bool GraphicsView::event(QEvent *event)
{
switch (event->type()) {
case QEvent::TouchBegin:
case QEvent::TouchUpdate:
case QEvent::TouchEnd:
{
QList<QTouchEvent::TouchPoint> touchPoints = static_cast<QTouchEvent *>(event)->touchPoints();
if (touchPoints.count() == 2) {
// determine scale factor
const QTouchEvent::TouchPoint &touchPoint0 = touchPoints.first();
const QTouchEvent::TouchPoint &touchPoint1 = touchPoints.last();
const qreal scaleFactor = QLineF(touchPoint0.pos(), touchPoint1.pos()).length()
/ QLineF(touchPoint0.startPos(), touchPoint1.startPos()).length();
setTransform(QTransform().scale(scaleFactor, scaleFactor));
}
return true;
}
default:
break;
}
return QGraphicsView::event(event);
}
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