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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 <QtGui>
class PannableGraphicsView : public QGraphicsView
{
public:
PannableGraphicsView()
{
grabGesture(Qt::PanGesture);
}
protected:
bool event(QEvent *event)
{
if (event->type() == QEvent::Gesture) {
QGestureEvent *gestureEvent = static_cast<QGestureEvent*>(event);
if (const QGesture *g = gestureEvent->gesture(Qt::PanGesture)) {
QPoint pt = g->pos() - g->lastPos();
horizontalScrollBar()->setValue(horizontalScrollBar()->value() - pt.x());
verticalScrollBar()->setValue(verticalScrollBar()->value() - pt.y());
event->accept();
return true;
}
}
return QGraphicsView::event(event);
}
};
class ImageItem : public QGraphicsItem
{
public:
ImageItem()
: colored(false)
{
grabGesture(Qt::DoubleTapGesture);
}
QRectF boundingRect() const
{
return pixmap.isNull() ? QRectF(0, 0, 100, 100)
: QRectF(QPointF(0,0), QSizeF(pixmap.size()));
}
void paint(QPainter *painter, const QStyleOptionGraphicsItem*, QWidget*)
{
if (pixmap.isNull()) {
painter->setBrush(QBrush( colored ? Qt::green : Qt::white));
painter->drawRect(0, 0, 100, 100);
painter->drawLine(0, 0, 100, 100);
painter->drawLine(0, 100, 100, 0);
return;
}
painter->drawPixmap(0, 0, pixmap);
}
bool sceneEvent(QEvent *event)
{
if (event->type() == QEvent::GraphicsSceneGesture) {
QGraphicsSceneGestureEvent *gestureEvent = static_cast<QGraphicsSceneGestureEvent*>(event);
if (gestureEvent->gesture(Qt::DoubleTapGesture)) {
event->accept();
colored = !colored;
update();
return true;
} else {
qWarning("Item received unknown gesture");
}
}
return QGraphicsItem::sceneEvent(event);
}
private:
QPixmap pixmap;
bool colored;
};
class MainWidget : public QWidget
{
Q_OBJECT
public:
MainWidget(QWidget *parent = 0)
: QWidget(parent)
{
QVBoxLayout *l = new QVBoxLayout(this);
view = new PannableGraphicsView;
l->addWidget(view);
scene = new QGraphicsScene(0, 0, 1024, 768, view);
view->setScene(scene);
ImageItem *item = new ImageItem;
scene->addItem(item);
item->setPos(scene->width()/3, scene->height()/3);
}
signals:
public slots:
private:
QGraphicsView *view;
QGraphicsScene *scene;
};
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QApplication::setAttribute(Qt::AA_EnableGestures);
MainWidget w;
w.show();
return app.exec();
}
#include "main.moc"
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