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/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the $MODULE$ of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** 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 qt-sales@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/

#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);
}