src/pixmapviewer.cpp

   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 #include "pixmapviewer.h"
  21
  22 #include <kiconloader.h>
  23
  24 #include <QPainter>
  25 #include <QPixmap>
  26 #include <QKeyEvent>
  27
  28 PixmapViewer::PixmapViewer(QWidget* parent, Transition transition) :
  29     QWidget(parent),
  30     m_transition(transition),
  31     m_animationStep(0)
  32 {
  33     setMinimumWidth(KIconLoader::SizeEnormous);
  34     setMinimumHeight(KIconLoader::SizeEnormous);
  35
  36     m_animation.setDuration(150);
  37     m_animation.setCurveShape(QTimeLine::LinearCurve);
  38
  39     if (m_transition != NoTransition) {
  40         connect(&m_animation, SIGNAL(valueChanged(qreal)), this, SLOT(update()));
  41         connect(&m_animation, SIGNAL(finished()), this, SLOT(checkPendingPixmaps()));
  42     }
  43 }
  44
  45 PixmapViewer::~PixmapViewer()
  46 {
  47 }
  48
  49 void PixmapViewer::setPixmap(const QPixmap& pixmap)
  50 {
  51     if (pixmap.isNull()) {
  52         return;
  53     }
  54
  55     if ((m_transition != NoTransition) && (m_animation.state() == QTimeLine::Running)) {
  56         m_pendingPixmaps.enqueue(pixmap);
  57         if (m_pendingPixmaps.count() > 5) {
  58             // don't queue more than 5 pixmaps
  59             m_pendingPixmaps.takeFirst();
  60         }
  61         return;
  62     }
  63
  64     m_oldPixmap = m_pixmap.isNull() ? pixmap : m_pixmap;
  65     m_pixmap = pixmap;
  66     update();
  67
  68     const bool animate = (m_transition != NoTransition) &&
  69                          (m_pixmap.size() != m_oldPixmap.size());
  70     if (animate) {
  71         m_animation.start();
  72     }
  73 }
  74
  75 void PixmapViewer::paintEvent(QPaintEvent* event)
  76 {
  77     QWidget::paintEvent(event);
  78
  79     QPainter painter(this);
  80
  81     if (m_transition != NoTransition) {
  82         const float value = m_animation.currentValue();
  83         const int scaledWidth  = static_cast<int>((m_oldPixmap.width()  * (1.0 - value)) + (m_pixmap.width()  * value));
  84         const int scaledHeight = static_cast<int>((m_oldPixmap.height() * (1.0 - value)) + (m_pixmap.height() * value));
  85
  86         const int x = (width()  - scaledWidth ) / 2;
  87         const int y = (height() - scaledHeight) / 2;
  88
  89         const bool useOldPixmap = (m_transition == SizeTransition) &&
  90                                   (m_oldPixmap.width() > m_pixmap.width());
  91         const QPixmap& largePixmap = useOldPixmap ? m_oldPixmap : m_pixmap;
  92         const QPixmap scaledPixmap = largePixmap.scaled(scaledWidth,
  93                                                         scaledHeight,
  94                                                         Qt::IgnoreAspectRatio,
  95                                                         Qt::FastTransformation);
  96         painter.drawPixmap(x, y, scaledPixmap);
  97     } else {
  98         const int x = (width()  - m_pixmap.width() ) / 2;
  99         const int y = (height() - m_pixmap.height()) / 2;
 100         painter.drawPixmap(x, y, m_pixmap);
 101     }
 102 }
 103
 104 void PixmapViewer::checkPendingPixmaps()
 105 {
 106     if (m_pendingPixmaps.count() > 0) {
 107         QPixmap pixmap = m_pendingPixmaps.dequeue();
 108         m_oldPixmap = m_pixmap.isNull() ? pixmap : m_pixmap;
 109         m_pixmap = pixmap;
 110         update();
 111         m_animation.start();
 112     } else {
 113         m_oldPixmap = m_pixmap;
 114     }
 115 }
 116
 117 #include "pixmapviewer.moc"