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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 documentation 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 Technology Preview License Agreement accompanying
** this package.
**
** 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 1.1, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QtGui>
class MyScrollArea : public QAbstractScrollArea
{
public:
MyScrollArea(QWidget *w);
void setWidget(QWidget *w);
protected:
void scrollContentsBy(int dx, int dy);
void resizeEvent(QResizeEvent *event);
private:
void updateWidgetPosition();
void updateArea();
QWidget *widget;
};
MyScrollArea::MyScrollArea(QWidget *widget)
: QAbstractScrollArea()
{
setWidget(widget);
}
void MyScrollArea::setWidget(QWidget *w)
{
widget = w;
widget->setParent(viewport());
if (!widget->testAttribute(Qt::WA_Resized))
widget->resize(widget->sizeHint());
verticalScrollBar()->setValue(0);
verticalScrollBar()->setValue(0);
updateArea();
}
void MyScrollArea::updateWidgetPosition()
{
//! [0]
int hvalue = horizontalScrollBar()->value();
int vvalue = verticalScrollBar()->value();
QPoint topLeft = viewport()->rect().topLeft();
widget->move(topLeft.x() - hvalue, topLeft.y() - vvalue);
//! [0]
}
void MyScrollArea::scrollContentsBy(int /*dx*/, int /*dy*/)
{
updateWidgetPosition();
}
void MyScrollArea::updateArea()
{
//! [1]
QSize areaSize = viewport()->size();
QSize widgetSize = widget->size();
verticalScrollBar()->setPageStep(widgetSize.height());
horizontalScrollBar()->setPageStep(widgetSize.width());
verticalScrollBar()->setRange(0, widgetSize.height() - areaSize.height());
horizontalScrollBar()->setRange(0, widgetSize.width() - areaSize.width());
updateWidgetPosition();
//! [1]
}
void MyScrollArea::resizeEvent(QResizeEvent *event)
{
updateArea();
}
int main(int argv, char **args)
{
QApplication app(argv, args);
QPixmap pixmap("mypixmap.png");
QLabel label;
label.setPixmap(pixmap);
MyScrollArea area(&label);
area.resize(300, 300);
area.show();
area.setWidget(&label);
return app.exec();
}
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