apps/dolphin/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 <QLayout>
  25 #include <QPainter>
  26 #include <QPixmap>
  27 #include <QKeyEvent>
  28
  29 PixmapViewer::PixmapViewer(QWidget* parent, Transition transition) :
  30     QWidget(parent),
  31     m_transition(transition),
  32     m_animationStep(0),
  33     m_sizeHint()
  34 {
  35     setMinimumWidth(KIconLoader::SizeEnormous);
  36     setMinimumHeight(KIconLoader::SizeEnormous);
  37
  38     m_animation.setDuration(150);
  39     m_animation.setCurveShape(QTimeLine::LinearCurve);
  40
  41     if (m_transition != NoTransition) {
  42         connect(&m_animation, SIGNAL(valueChanged(qreal)), this, SLOT(update()));
  43         connect(&m_animation, SIGNAL(finished()), this, SLOT(checkPendingPixmaps()));
  44     }
  45 }
  46
  47 PixmapViewer::~PixmapViewer()
  48 {
  49 }
  50
  51 void PixmapViewer::setPixmap(const QPixmap& pixmap)
  52 {
  53     if (pixmap.isNull()) {
  54         return;
  55     }
  56
  57     if ((m_transition != NoTransition) && (m_animation.state() == QTimeLine::Running)) {
  58         m_pendingPixmaps.enqueue(pixmap);
  59         if (m_pendingPixmaps.count() > 5) {
  60             // don't queue more than 5 pixmaps
  61             m_pendingPixmaps.takeFirst();
  62         }
  63         return;
  64     }
  65
  66     m_oldPixmap = m_pixmap.isNull() ? pixmap : m_pixmap;
  67     m_pixmap = pixmap;
  68     update();
  69
  70     const bool animate = (m_transition != NoTransition) &&
  71                          (m_pixmap.size() != m_oldPixmap.size());
  72     if (animate) {
  73         m_animation.start();
  74     }
  75 }
  76
  77 void PixmapViewer::setSizeHint(const QSize& size)
  78 {
  79     m_sizeHint = size;
  80     updateGeometry();
  81 }
  82
  83 QSize PixmapViewer::sizeHint() const
  84 {
  85     return m_sizeHint;
  86 }
  87
  88 void PixmapViewer::paintEvent(QPaintEvent* event)
  89 {
  90     QWidget::paintEvent(event);
  91
  92     QPainter painter(this);
  93
  94     if (m_transition != NoTransition) {
  95         const float value = m_animation.currentValue();
  96         const int scaledWidth  = static_cast<int>((m_oldPixmap.width()  * (1.0 - value)) + (m_pixmap.width()  * value));
  97         const int scaledHeight = static_cast<int>((m_oldPixmap.height() * (1.0 - value)) + (m_pixmap.height() * value));
  98
  99         const int x = (width()  - scaledWidth ) / 2;
 100         const int y = (height() - scaledHeight) / 2;
 101
 102         const bool useOldPixmap = (m_transition == SizeTransition) &&
 103                                   (m_oldPixmap.width() > m_pixmap.width());
 104         const QPixmap& largePixmap = useOldPixmap ? m_oldPixmap : m_pixmap;
 105         const QPixmap scaledPixmap = largePixmap.scaled(scaledWidth,
 106                                                         scaledHeight,
 107                                                         Qt::IgnoreAspectRatio,
 108                                                         Qt::FastTransformation);
 109         painter.drawPixmap(x, y, scaledPixmap);
 110     } else {
 111         const int x = (width()  - m_pixmap.width() ) / 2;
 112         const int y = (height() - m_pixmap.height()) / 2;
 113         painter.drawPixmap(x, y, m_pixmap);
 114     }
 115 }
 116
 117 void PixmapViewer::checkPendingPixmaps()
 118 {
 119     if (m_pendingPixmaps.count() > 0) {
 120         QPixmap pixmap = m_pendingPixmaps.dequeue();
 121         m_oldPixmap = m_pixmap.isNull() ? pixmap : m_pixmap;
 122         m_pixmap = pixmap;
 123         update();
 124         m_animation.start();
 125     } else {
 126         m_oldPixmap = m_pixmap;
 127     }
 128 }
 129
 130 #include "pixmapviewer.moc"