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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 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 qt-sales@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#include "shadoweffect.h"
#include <math.h>
ShadowEffect::ShadowEffect(QGraphicsItem *item, QGraphicsItem *source)
: QGraphicsShadowEffect()
, item(item), m_lightSource(source)
{
setBlurRadius(8);
}
void ShadowEffect::adjustForItem()
{
QPointF delta = item->pos() - m_lightSource->pos();
setShadowOffset(delta.toPoint() / 30);
qreal dx = delta.x();
qreal dy = delta.y();
qreal dd = sqrt(dx * dx + dy * dy);
setOpacity(qBound(0.4, 1 - dd / 200.0, 0.7));
}
QRectF ShadowEffect::boundingRectFor(const QRectF &rect) const
{
const_cast<ShadowEffect *>(this)->adjustForItem();
return QGraphicsShadowEffect::boundingRectFor(rect);
}
void ShadowEffect::draw(QPainter *painter, QGraphicsEffectSource *source)
{
adjustForItem();
QGraphicsShadowEffect::draw(painter, source);
}
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