src/pixmapviewer.h

   1 /***************************************************************************
   2  *   Copyright (C) 2006 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 PIXMAPVIEWER_H
  21 #define PIXMAPVIEWER_H
  22
  23 #include <QWidget>
  24 #include <QPixmap>
  25 #include <QQueue>
  26 #include <QTimeLine>
  27
  28 class QPaintEvent;
  29
  30 /**
  31  * @brief Widget which shows a pixmap centered inside the boundaries.
  32  *
  33  * When the pixmap is changed, a smooth transition is done from the old pixmap
  34  * to the new pixmap.
  35  */
  36 class PixmapViewer : public QWidget
  37 {
  38     Q_OBJECT
  39
  40 public:
  41     enum Transition
  42     {
  43         /** No transition is done when the pixmap is changed. */
  44         NoTransition,
  45
  46         /**
  47          * The old pixmap is replaced by the new pixmap and the size is
  48          * adjusted smoothly to the size of the new pixmap.
  49          */
  50         DefaultTransition,
  51
  52         /**
  53          * If the old pixmap and the new pixmap have the same content, but
  54          * a different size it is recommended to use Transition::SizeTransition
  55          * instead of Transition::DefaultTransition. In this case it is assured
  56          * that the larger pixmap is used for downscaling, which leads
  57          * to an improved scaling output.
  58          */
  59         SizeTransition
  60     };
  61
  62     explicit PixmapViewer(QWidget* parent,
  63                           Transition transition = DefaultTransition);
  64
  65     virtual ~PixmapViewer();
  66     void setPixmap(const QPixmap& pixmap);
  67     const QPixmap& pixmap() const;
  68
  69 protected:
  70     virtual void paintEvent(QPaintEvent* event);
  71
  72 private Q_SLOTS:
  73     void checkPendingPixmaps();
  74
  75 private:
  76     QPixmap m_pixmap;
  77     QPixmap m_oldPixmap;
  78     QQueue<QPixmap> m_pendingPixmaps;
  79     QTimeLine m_animation;
  80     Transition m_transition;
  81     int m_animationStep;
  82 };
  83
  84 inline const QPixmap& PixmapViewer::pixmap() const
  85 {
  86     return m_pixmap;
  87 }
  88
  89
  90 #endif