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/***************************************************************************
* Copyright (C) 2011 by Peter Penz <[email protected]> *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA *
***************************************************************************/
#ifndef KITEMLISTSMOOTHSCROLLER_H
#define KITEMLISTSMOOTHSCROLLER_H
#include "dolphin_export.h"
#include <QAbstractAnimation>
#include <QObject>
class QPropertyAnimation;
class QScrollBar;
class QWheelEvent;
/**
* @brief Helper class for KItemListContainer to have a smooth
* scrolling when adjusting the scrollbars.
*/
class DOLPHIN_EXPORT KItemListSmoothScroller : public QObject
{
Q_OBJECT
public:
explicit KItemListSmoothScroller(QScrollBar* scrollBar,
QObject* parent = 0);
virtual ~KItemListSmoothScroller();
void setScrollBar(QScrollBar* scrollBar);
QScrollBar* scrollBar() const;
void setTargetObject(QObject* target);
QObject* targetObject() const;
void setPropertyName(const QByteArray& propertyName);
QByteArray propertyName() const;
/**
* Adjusts the position of the target by \p distance
* pixels. Is invoked in the context of QAbstractScrollArea::scrollContentsBy()
* where the scrollbars already have the new position but the content
* has not been scrolled yet.
*/
void scrollContentsBy(qreal distance);
/**
* Does a smooth-scrolling to the position \p position
* on the target and also adjusts the corresponding scrollbar
* to the new position.
*/
void scrollTo(qreal position);
/**
* Must be invoked before the scrollbar should get updated to have a new
* maximum. True is returned if the new maximum can be applied. If false
* is returned the maximum has already been reached and the value will
* be reached at the end of the animation.
*/
// TODO: This interface is tricky to understand. Try to make this more
// generic/readable if the corresponding code in KItemListContainer got
// stable.
bool requestScrollBarUpdate(int newMaximum);
protected:
virtual bool eventFilter(QObject* obj, QEvent* event);
private slots:
void slotAnimationStateChanged(QAbstractAnimation::State newState,
QAbstractAnimation::State oldState);
private:
/**
* Results into a smooth-scrolling of the target dependent on the direction
* of the wheel event.
*/
void handleWheelEvent(QWheelEvent* event);
private:
bool m_scrollBarPressed;
bool m_smoothScrolling;
QScrollBar* m_scrollBar;
QPropertyAnimation* m_animation;
};
#endif
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