apps/dolphin/src/dolphinviewautoscroller.h

   1 /***************************************************************************
   2  *   Copyright (C) 2008 by Peter Penz <peter.penz@gmx.at>                  *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program; if not, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  18  ***************************************************************************/
  19
  20 #ifndef DOLPHINVIEWAUTOSCROLLER_H
  21 #define DOLPHINVIEWAUTOSCROLLER_H
  22
  23 #include <QObject>
  24
  25 class QAbstractItemView;
  26 class QTimer;
  27
  28 /**
  29  * @brief Assures that an autoscrolling is done for item views.
  30  *
  31  * This is a workaround as QAbstractItemView::setAutoScroll() is not usable
  32  * when selecting items (see Qt issue #214542).
  33  */
  34 class DolphinViewAutoScroller : public QObject
  35 {
  36     Q_OBJECT
  37
  38 public:
  39     DolphinViewAutoScroller(QAbstractItemView* parent);
  40     virtual ~DolphinViewAutoScroller();
  41     bool isActive() const;
  42
  43 protected:
  44     virtual bool eventFilter(QObject* watched, QEvent* event);
  45
  46 private slots:
  47     void scrollViewport();
  48
  49 private:
  50     void triggerAutoScroll();
  51     void stopAutoScroll();
  52
  53     /**
  54      * Calculates the scroll increment dependent from
  55      * the cursor position \a cursorPos and the range 0 - \a rangeSize - 1.
  56      */
  57     int calculateScrollIncrement(int cursorPos, int rangeSize) const;
  58
  59 private:
  60     bool m_rubberBandSelection;
  61     int m_horizontalScrollInc;
  62     int m_verticalScrollInc;
  63     QAbstractItemView* m_itemView;
  64     QTimer* m_timer;
  65 };
  66
  67 #endif