src/panels/information/pixmapviewer.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2006 by Peter Penz <peter.penz19@gmail.com>             *
   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>
  23
  24 #include <QPainter>
  25 #include <QStyle>
  26
  27 PixmapViewer::PixmapViewer(QWidget* parent, Transition transition) :
  28     QWidget(parent),
  29     m_transition(transition),
  30     m_animationStep(0),
  31     m_sizeHint()
  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, &QTimeLine::valueChanged, this, static_cast<void(PixmapViewer::*)()>(&PixmapViewer::update));
  41         connect(&m_animation, &QTimeLine::finished, this, &PixmapViewer::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::setSizeHint(const QSize& size)
  76 {
  77     m_sizeHint = size;
  78     updateGeometry();
  79 }
  80
  81 QSize PixmapViewer::sizeHint() const
  82 {
  83     return m_sizeHint;
  84 }
  85
  86 void PixmapViewer::paintEvent(QPaintEvent* event)
  87 {
  88     QWidget::paintEvent(event);
  89
  90     QPainter painter(this);
  91
  92     if (m_transition != NoTransition) {
  93         const float value = m_animation.currentValue();
  94         const int scaledWidth  = static_cast<int>((m_oldPixmap.width()  * (1.0 - value)) + (m_pixmap.width()  * value));
  95         const int scaledHeight = static_cast<int>((m_oldPixmap.height() * (1.0 - value)) + (m_pixmap.height() * value));
  96
  97         const bool useOldPixmap = (m_transition == SizeTransition) &&
  98                                   (m_oldPixmap.width() > m_pixmap.width());
  99         const QPixmap& largePixmap = useOldPixmap ? m_oldPixmap : m_pixmap;
 100         if (!largePixmap.isNull()) {
 101             const QPixmap scaledPixmap = largePixmap.scaled(scaledWidth,
 102                                                             scaledHeight,
 103                                                             Qt::IgnoreAspectRatio,
 104                                                             Qt::FastTransformation);
 105
 106             style()->drawItemPixmap(&painter, rect(), Qt::AlignCenter, scaledPixmap);
 107         }
 108     } else {
 109         style()->drawItemPixmap(&painter, rect(), Qt::AlignCenter, m_pixmap);
 110     }
 111 }
 112
 113 void PixmapViewer::checkPendingPixmaps()
 114 {
 115     if (!m_pendingPixmaps.isEmpty()) {
 116         QPixmap pixmap = m_pendingPixmaps.dequeue();
 117         m_oldPixmap = m_pixmap.isNull() ? pixmap : m_pixmap;
 118         m_pixmap = pixmap;
 119         update();
 120         m_animation.start();
 121     } else {
 122         m_oldPixmap = m_pixmap;
 123     }
 124 }
 125