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Diffstat (limited to 'examples/multitouch/pinchzoom/graphicsview.cpp')
-rw-r--r-- | examples/multitouch/pinchzoom/graphicsview.cpp | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/examples/multitouch/pinchzoom/graphicsview.cpp b/examples/multitouch/pinchzoom/graphicsview.cpp new file mode 100644 index 0000000..ca2f519 --- /dev/null +++ b/examples/multitouch/pinchzoom/graphicsview.cpp @@ -0,0 +1,76 @@ +/**************************************************************************** +** +** 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); +} |