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/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
** of its contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#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(areaSize.height());
horizontalScrollBar()->setPageStep(areaSize.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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