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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);
+}