dolphin/src/dolphinviewautoscroller.h
2009-12-06 13:05:56 +00:00

80 lines
2.8 KiB
C++

/***************************************************************************
* Copyright (C) 2008 by Peter Penz <peter.penz@gmx.at> *
* *
* 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 DOLPHINVIEWAUTOSCROLLER_H
#define DOLPHINVIEWAUTOSCROLLER_H
#include <QTime>
#include <QObject>
class QAbstractItemView;
class QModelIndex;
class QTimer;
/**
* @brief Assures that an autoscrolling is done for item views.
*
* This is a workaround as QAbstractItemView::setAutoScroll() is not usable
* when selecting items (see Qt issue #214542).
*/
class DolphinViewAutoScroller : public QObject
{
Q_OBJECT
public:
DolphinViewAutoScroller(QAbstractItemView* parent);
virtual ~DolphinViewAutoScroller();
bool isActive() const;
/**
* Must be invoked by the parent item view, when QAbstractItemView::currentChanged()
* has been called. Assures that the current item stays visible when it has been
* changed by the keyboard.
*/
void handleCurrentIndexChange(const QModelIndex& current, const QModelIndex& previous);
protected:
virtual bool eventFilter(QObject* watched, QEvent* event);
private slots:
void scrollViewport();
private:
void triggerAutoScroll();
void stopAutoScroll();
/**
* Calculates the scroll increment dependent from
* the cursor position \a cursorPos and the range 0 - \a rangeSize - 1.
*/
int calculateScrollIncrement(int cursorPos, int rangeSize) const;
private:
bool m_rubberBandSelection;
bool m_keyPressed;
bool m_initializedTimestamp;
int m_horizontalScrollInc;
int m_verticalScrollInc;
QAbstractItemView* m_itemView;
QTimer* m_timer;
QTime m_timestamp;
};
#endif